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13 STATE OF WASHINGTON
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15 KING COUNTY SUPERIOR COURT
16
17 STATE OF WASHINGTON,
18 DEPARTMENT OF ECOLOGY, NO. __________
19
20 Plaintiff,
21 CONSENT DECREE RE: LORA LAKE
22 v. APARTMENTS SITE, BURIEN,
23 WASHINGTON
24 Port of Seattle,
25
26 Defendant.
27
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31 TABLE OF CONTENTS
32
33 I. INTRODUCTION .......................................................................................................
34 II. JURISDICTION ..........................................................................................................
35 III. PARTIES BOUND ......................................................................................................
36 IV. DEFINITIONS.............................................................................................................
37 V. FINDINGS OF FACTS ...............................................................................................
38 VI. WORK TO BE PERFORMED ....................................................................................
39 VII. DESIGNATED PROJECT COORDINATORS ..........................................................
40 VIII. PERFORMANCE ........................................................................................................
41 IX. ACCESS ......................................................................................................................
42 X. SAMPLING, DATA SUBMITTAL, AND AVAILABILITY ....................................
43 XI. PROGRESS REPORTS ...............................................................................................
44 XII. RETENTION OF RECORDS .....................................................................................
45 XIII. TRANSFER OF INTEREST IN PROPERTY ............................................................
46 XIV. RESOLUTION OF DISPUTES...................................................................................
47 XV. AMENDMENT OF DECREE .....................................................................................
48 XVI. EXTENSION OF SCHEDULE ...................................................................................
49 XVII. ENDANGERMENT ....................................................................................................
50 XVIII. COVENANT NOT TO SUE .......................................................................................
51 XIX. CONTRIBUTION PROTECTION .............................................................................
CONSENT DECREE RE: 1 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 XX. LAND USE RESTRICTIONS.....................................................................................
2 XXI. FINANCIAL ASSURANCES .....................................................................................
3 XXII. INDEMNIFICATION .................................................................................................
4 XXIII. COMPLIANCE WITH APPLICABLE LAWS ..........................................................
5 XXIV. REMEDIAL ACTION COSTS ...................................................................................
6 XXV. IMPLEMENTATION OF REMEDIAL ACTION ......................................................
7 XXVI. PERIODIC REVIEW ..................................................................................................
8 XXVII. PUBLIC PARTICIPATION ........................................................................................
9 XXVIII. DURATION OF DECREE ..........................................................................................
10 XXIX. CLAIMS AGAINST THE STATE..............................................................................
11 XXX. EFFECTIVE DATE .....................................................................................................
12 XXXI. WITHDRAWAL OF CONSENT ................................................................................
13
14 EXHIBIT A. Site Diagram
15 EXHIBIT B. Cleanup Action Plan
16 EXHIBIT C. Scope of Work and Schedule
17 EXHIBIT D. Applicable or Relevant and Appropriate Requirements
18 EXHIBIT E. Procedurally Exempt Requirements
19
20
21
CONSENT DECREE RE: 2 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 I. INTRODUCTION
2
3 A. The mutual objective of the State of Washington, Department of Ecology
4 (Ecology) and Port of Seattle (Defendant) under this Decree is to provide for remedial action at
5 a facility where there has been a release or threatened release of hazardous substances. This
6 Decree requires Defendant to perform a final cleanup of the Lora Lake Apartments Site in
7 Burien, Washington.
8 B. Ecology has determined that these actions are necessary to protect human health
9 and the environment.
10 C. The Complaint in this action is being filed simultaneously with this Decree. An
11 Answer has not been filed, and there has not been a trial on any issue of fact or law in this case.
12 However, the Parties wish to resolve the issues raised by Ecology's Complaint. In addition, the
13 Parties agree that settlement of these matters without litigation is reasonable and in the public
14 interest, and that entry of this Decree is the most appropriate means of resolving these matters.
15 D. By signing this Decree, the Parties agree to its entry and agree to be bound by its
16 terms.
17 E. By entering into this Decree, the Parties do not intend to discharge non-settling
18 parties from any liability they may have with respect to matters alleged in the Complaint. The
19 Parties retain the right to seek reimbursement, in whole or in part, from any liable persons for
20 sums expended under this Decree.
21 F. This Decree shall not be construed as proof of liability or responsibility for any
22 releases of hazardous substances or cost for remedial action nor an admission of any facts;
23 provided, however, that Defendant shall not challenge the authority of the Attorney General and
24 Ecology to enforce this Decree.
CONSENT DECREE RE: 3 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 G. The Court is fully advised of the reasons for entry of this Decree, and good cause
2 having been shown:
3 Now, therefore, it is HEREBY ORDERED, ADJUDGED, AND DECREED as follows:
4
5 II. JURISDICTION
6 A. This Court has jurisdiction over the subject matter and over the Parties pursuant
7 to the Model Toxics Control Act (MTCA), RCW 70.105D.
8 B. Authority is conferred upon the Washington State Attorney General by
9 RCW 70.105D.040(4)(a) to agree to a settlement with any potentially liable person (PLP) if,
10 after public notice and any required hearing, Ecology finds the proposed settlement would lead
11 to a more expeditious cleanup of hazardous substances. RCW 70.105D.040(4)(b) requires that
12 such a settlement be entered as a consent decree issued by a court of competent jurisdiction.
13 C. Ecology has determined that a release or threatened release of hazardous
14 substances has occurred at the Site that is the subject of this Decree.
15 D. Ecology has given notice to Defendant of Ecology's determination that Defendant
16 is a PLP for the Site, as required by RCW 70.105D.020(26) and WAC 173-340-500.
17 E. The actions to be taken pursuant to this Decree are necessary to protect public
18 health and the environment.
19 F. This Decree has been subject to public notice and comment.
20 G. Ecology finds that this Decree will lead to a more expeditious cleanup of
21 hazardous substances at the Site in compliance with the cleanup standards established under
22 RCW 70.105D.030(2)(e) and WAC 173-340.
23 H. Defendant has agreed to undertake the actions specified in this Decree and
24 consents to the entry of this Decree under MTCA.
CONSENT DECREE RE: 4 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 III. PARTIES BOUND
2 This Decree shall apply to and be binding upon the Parties to this Decree, their successors
3 and assigns. The undersigned representative of each party hereby certifies that he or she is fully
4 authorized to enter into this Decree and to execute and legally bind such party to comply with
5 this Decree. Defendant agrees to undertake all actions required by the terms and conditions of
6 this Decree. No change in ownership or corporate status shall alter Defendant's responsibility
7 under this Decree. Defendant shall provide a copy of this Decree to all agents, contractors, and
8 subcontractors retained to perform work required by this Decree, and shall ensure that all work
9 undertaken by such agents, contractors, and subcontractors complies with this Decree.
10 IV. DEFINITIONS
11 Unless otherwise specified herein, all definitions in RCW 70.105D.020 and
12 WAC 173-340-200 shall control the meanings of the terms in this Decree.
13 A. Site: The Site is referred to as the Lora Lake Apartments Site and is generally
14 located at 15001 Des Moines Memorial Drive, Burien, Washington. The Site is generally as
15 shown in the Site Diagram (Exhibit A), and more particularly as described in the Cleanup Action
16 Plan (Exhibit B, see Section 2.1 and Figure 2.1). The Site constitutes a facility under RCW
17 70.105D.020(8).
18 B. Parties: Refers to the State of Washington, Department of Ecology and the Port
19 of Seattle.
20 C. Defendant: Refers to the Port of Seattle.
21 D. Consent Decree or Decree: Refers to this Consent Decree and each of the exhibits
22 to this Decree. All exhibits are integral and enforceable parts of this Consent Decree. The terms
23 "Consent Decree" or "Decree" shall include all exhibits to this Consent Decree.
CONSENT DECREE RE: 5 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 V. FINDINGS OF FACTS
2 Ecology makes the following findings of fact without any express or implied admissions
3 of such facts by Defendant.
4 A. Defendant owns the Site.
5 B. Prior to 1940, the Lora Lake Apartments Parcel had both an orchard and a private
6 residence. During the 1940s and 1950s, Novak Barrel Cleaning Company operated at the Lora
7 Lake Apartments Parcel. From the mid-1950s to 1981, Burien Auto Wrecking operated at the
8 Lora Lake Apartments Parcel. In the 1986 to 1987 timeframe, the Mueller Group, a building
9 developer, purchased the Lora Lake Apartments Parcel, investigated and removed contaminated
10 soil, and constructed an apartment complex. After constructing the apartment complex, the
11 Mueller Group sold the property to Santa Anita Realty Enterprises, which transferred the
12 property to a wholly-owned subsidiary, Pacific Gulf Properties, Inc., in 1993. In 1998,
13 Defendant acquired the Lora Apartments Parcel from Pacific Gulf Properties, Inc. for conversion
14 to airport support (industrial) use, and vacated the apartments. Ownership of the Lora Lake
15 Apartments Parcel was temporarily transferred from Defendant to the King County Housing
16 Authority (KCHA) in May 2000. On July 20, 2007, the Defendant reacquired ownership of the
17 Lora Lake Apartments Parcel. Following reacquisition of the Lora Lake Apartments Parcel by
18 Defendant, six of the apartment buildings were demolished to comply with Federal Aviation
19 Administration (FAA) flight path requirements because of expansion at SeaTac International
20 Airport.
21 C. Defendant notified Ecology of soil and ground water contamination at the Site on
22 February 27, 2008.
23 D. Defendant and KCHA submitted a Voluntary Cleanup Program (VCP)
24 application to Ecology on April 4, 2008. The Defendant subsequently entered the VCP. The
CONSENT DECREE RE: 6 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 Defendant filed a Modified VCP application on September 23, 2008, removing KCHA from the
2 VCP application.
3 E. The modified VCP application listed polycyclic aromatic hydrocarbons,
4 hydrocarbons (gasoline, diesel, and oil), and dioxins as confirmed soil contaminants and these
5 same contaminants plus tetrachloroethene, trichloroethene, 1,2-dichloroethane, and arsenic as
6 confirmed groundwater contaminants. This contaminant list was refined during the subsequent
7 RI/FS.
8 F. Ecology notified Defendant of their potential liability for the Site under the Model
9 Toxics Control Act on February 3, 2009. Defendant accepted status as a Potentially Liable
10 Person on March 5, 2009.
11 G. Defendant entered into Agreed Order DE 6703 with Ecology on July 10, 2009,
12 requiring Defendant to complete interim remedial actions, prepare a Public Participation Plan,
13 complete a Supplemental Data Gaps Report, and complete a Remedial Investigation/Feasibility
14 Study (RI/FS) for all releases at the site. Agreed Order DE 6703 required Defendant to demolish
15 all buildings and ancillary above-ground facilities of the Lora Lake Apartments (excluding
16 foundations) as an interim remedial action. This interim remedial action was completed in the
17 summer of 2009.
18 H. The RI/FS identified arsenic, lead, total petroleum hydrocarbons,
19 pentachlorophenol, carcinogenic polycyclic aromatic hydrocarbons, ethylbenzene, toluene, and
20 dioxins/furans as soil contaminants; arsenic, total petroleum hydrocarbons, pentachlorophenol,
21 carcinogenic polycyclic aromatic hydrocarbons and dioxins/furans as groundwater
22 contaminants; and lead, arsenic, pentachlorophenol, carcinogenic polycyclic aromatic
23 hydrocarbons and dioxins/furans as sediment contaminants for all releases at the Site. During
24 the RI/FS, the site was extended to include portions of airport property east of Des Moines
25 Memorial Drive including Lora Lake and a former Dredged Material Containment Area.
CONSENT DECREE RE: 7 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 I. An active City of Burien stormwater system now runs through the Lora Lake
2 Apartments Parcel, connecting to the Des Moines Memorial Drive drainage system downstream
3 of the property and discharging to Lora Lake.
4 J. A second, smaller sub-system exists on the Lora Lake Apartments Parcel. The
5 sub-system currently drains the northeast portion of the parcel, conveying water to the Des
6 Moines Memorial Drive drainage system upstream of Lora Lake.
7 K. The RI/FS assessed stormwater chemical quality at multiple locations within the
8 interior of the Lora Lake Apartments Parcel as well as where the City of Burien main stormwater
9 line enters and exits the Lora Lake Apartments Parcel, and where the secondary line exits the
10 parcel. The assessment found that upon entry to the Lora Lake Apartments Parcel the City of
11 Burien's stormwater contained multiple chemicals of concern, including dioxins/furans, and
12 stormwater from the Lora Lake Apartments Parcel was not contributing to degradation of the
13 stormwater conveyed from upstream across the property to Lora Lake.
14 L. The First Amendment to Agreed Order DE 6703 with Ecology was effective
15 April 18, 2013, requiring Defendant to prepare a Draft Cleanup Action Plan. The Cleanup
16 Action Plan is attached to this Decree as Exhibit B.
17 VI. WORK TO BE PERFORMED
18 This Decree contains a program designed to protect human health and the environment
19 from the known release, or threatened release, of hazardous substances or contaminants at, on,
20 or from the Site.
21 A. Defendant shall conduct a final cleanup action at the Site by implementing the
22 Cleanup Action Plan (CAP) (Exhibit B) according to the Scope of Work and Schedule (Exhibit
23 C) and all other requirements of this Decree. The cleanup action includes, but is not limited to,
24 the following actions:
25 1. Remedial action design and confirmational data collection.
CONSENT DECREE RE: 8 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 2. Excavation of soil from the Lora Lake Apartments Parcel containing greater than 100
2 picograms per gram (pg/g) Toxicity Equivalent (TEQ) dioxins/furans, with off-site
3 disposal at a licensed disposal facility.
4 3. Soil from the Lora Lake Apartments Parcel containing greater than 13 pg/g, but less than
5 100 pg/g TEQ dioxins/furans, will either be excavated, or remain in situ beneath a
6 constructed engineered surface. Excavated material will be consolidated beneath a
7 constructed engineered surface, either within the Lora Lake Apartments Parcel or at the
8 Dredged Material Containment Area.
9 4. Excavation of soil from selected areas of the Lora Lake Shallow Soil Area sufficient to
10 bring the average dioxins/furans concentrations TEQ of the remaining soil to less than
11 the cleanup level cleanup level of 5.2 pg/g TEQ. Excavations will be backfilled and
12 replanted. Excavated material will be consolidated at the Dredged Material Containment
13 Area. It may also be sent off-site for disposal at a licensed disposal facility if that is more
14 efficient for construction scheduling.
15 5. Filling of Lora Lake and conversion of the open-water lake to a rehabilitated wetland.
16 6. Modification of the stormwater conveyance system that crosses the Lora Lake
17 Apartments Parcel to eliminate the potential for contamination associated with the Site
18 to enter the stormwater system.
19 The Parties intend that the above list include any and all outstanding obligations under Agreed
20 Order DE 6703. The Parties agree that Agreed Order DE 6703 no longer has any force or effect.
21 B. The Defendant will submit for Ecology's review and approval the following
22 documents in accordance with the Schedule: engineering design report, the plans and
23 specifications, compliance monitoring plan, as-built documentation, and operations and
24 maintenance manual for any equipment or systems that are part of the remedy. The Scope of
CONSENT DECREE RE: 9 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 Work and Schedule (Exhibit C) details those deliverables that have been identified at the time
2 of entry of this Decree.
3 C. Defendant agrees not to perform any remedial actions outside the scope of this
4 Decree unless the Parties agree to modify the CAP (Exhibit B), the Scope of Work and Schedule
5 (Exhibit C) to cover these actions. All work conducted by Defendant under this Decree shall be
6 done in accordance with WAC 173-340 unless otherwise provided herein.
7 D. All plans or other deliverables submitted by the Port of Seattle for Ecology's
8 review and approval under the Scope of Work and Schedule (Exhibit C) shall, upon Ecology's
9 approval, become integral and enforceable parts of this Decree.
10 VII. DESIGNATED PROJECT COORDINATORS
11 The project coordinator for Ecology is:
12
13 Sunny Becker
14 Toxics Cleanup Program
15 Department of Ecology, Northwest Regional Office
16 3190 160th Avenue
17 Bellevue, WA 98008-5452
18 (425) 649-7187
19 Sunny.becker@ecy.wa.gov
20 The project coordinator for Defendant is:
21
22 Don Robbins
23 Port of Seattle
24 Aviation/Environmental
25 P.O. Box 68727
26 Seattle, WA 98168
27 206-787-4918
28 Robbins.D@portseattle.org
29 Each project coordinator shall be responsible for overseeing the implementation of this
30 Decree. Ecology's project coordinator will be Ecology's designated representative for the Site.
31 To the maximum extent possible, communications between Ecology and Defendant and all
32 documents, including reports, approvals, and other correspondence concerning the activities
33 performed pursuant to the terms and conditions of this Decree shall be directed through the
CONSENT DECREE RE: 10 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 project coordinators. The project coordinators may designate, in writing, working level staff
2 contacts for all or portions of the implementation of the work to be performed required by this
3 Decree.
4 Any party may change its respective project coordinator. Written notification shall be
5 given to the other party at least ten (10) calendar days prior to the change.
6 VIII. PERFORMANCE
7 All geologic and hydrogeologic work performed pursuant to this Decree shall be under
8 the supervision and direction of a geologist or hydrogeologist licensed in the State of Washington
9 or under the direct supervision of an engineer registered in the State of Washington, except as
10 otherwise provided for by RCW 18.220 and 18.43.
11 All engineering work performed pursuant to this Decree shall be under the direct
12 supervision of a professional engineer registered in the State of Washington, except as otherwise
13 provided for by RCW 18.43.130.
14 All construction work performed pursuant to this Decree shall be under the direct
15 supervision of a professional engineer or a qualified technician under the direct supervision of a
16 professional engineer. The professional engineer must be registered in the State of Washington,
17 except as otherwise provided for by RCW 18.43.130.
18 Any documents submitted containing geologic, hydrologic or engineering work shall be
19 under the seal of an appropriately licensed professional as required by RCW 18.220 and 18.43.
20 Defendant shall notify Ecology in writing of the identity of any engineer(s) and
21 geologist(s), contractor(s) and subcontractor(s), and others to be used in carrying out the terms
22 of this Decree, in advance of their involvement at the Site.
23 IX. ACCESS
24 Ecology or any Ecology authorized representative shall have access to enter and freely
25 move about all property at the Site that Defendant either owns, controls, or has access rights to
26 at all reasonable times for the purposes of, inter alia: inspecting records, operation logs, and
27 contracts related to the work being performed pursuant to this Decree; reviewing Defendant's
CONSENT DECREE RE: 11 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 progress in carrying out the terms of this Decree; conducting such tests or collecting such
2 samples as Ecology may deem necessary; using a camera, sound recording, or other documentary
3 type equipment to record work done pursuant to this Decree; and verifying the data submitted to
4 Ecology by Defendant. Defendant shall make all reasonable efforts to secure access rights for
5 those properties within the Site not owned or controlled by Defendant where remedial activities
6 or investigations will be performed pursuant to this Decree. Ecology or any Ecology authorized
7 representative shall give reasonable notice before entering any Site property owned or controlled
8 by Defendant unless an emergency prevents such notice. All Parties who access the Site pursuant
9 to this Section shall comply with any applicable health and safety plan(s). Ecology employees
10 and their representatives shall follow any appropriate safety and security precautions required
11 by the Port as part of their established safety and security procedures that Ecology has consented
12 to in advance of accessing the Site. Ecology employees and their representatives shall not be
13 required to sign any liability release or waiver as a condition of Site property access.
14 X. SAMPLING, DATA SUBMITTAL, AND AVAILABILITY
15 With respect to the implementation of this Decree, Defendant shall make the results of
16 all sampling, laboratory reports, and/or test results generated by it or on its behalf available to
17 Ecology. Pursuant to WAC 173-340-840(5), all sampling data, including ground water elevation
18 data, shall be submitted to Ecology in both printed and electronic formats in accordance with
19 Section XI (Progress Reports), Ecology's Toxics Cleanup Program Policy 840 (Data Submittal
20 Requirements), and/or any subsequent procedures specified by Ecology for data submittal.
21 If requested by Ecology, Defendant shall allow Ecology and/or its authorized
22 representative to take split or duplicate samples of any samples collected by Defendant pursuant
23 to the implementation of this Decree. Defendant shall notify Ecology seven (7) days in advance
24 of any sample collection or work activity at the Site. Ecology shall, upon request, allow
25 Defendant and/or its authorized representative to take split or duplicate samples of any samples
CONSENT DECREE RE: 12 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 collected by Ecology pursuant to the implementation of this Decree, provided that doing so does
2 not interfere with Ecology's sampling. Without limitation on Ecology's rights under Section IX
3 (Access), Ecology shall notify Defendant prior to any sample collection activity unless an
4 emergency prevents such notice.
5 In accordance with WAC 173-340-830(2)(a), all hazardous substance analyses shall be
6 conducted by a laboratory accredited under WAC 173-50 for the specific analyses to be
7 conducted, unless otherwise approved by Ecology.
8 XI. PROGRESS REPORTS
9 Defendant shall submit to Ecology written monthly Progress Reports that describe the
10 actions taken during the previous month to implement the requirements of this Decree. The
11 Progress Reports shall include the following:
12 A. A list of on-site activities that have taken place during the month;
13 B. Detailed description of any deviations from required tasks not otherwise
14 documented in project plans or amendment requests;
15 C. Description of all deviations from the Scope of Work and Schedule (Exhibit C)
16 during the current month and any planned deviations in the upcoming month;
17 D. For any deviations in schedule, a plan for recovering lost time and maintaining
18 compliance with the schedule;
19 E. All raw data (including laboratory analyses and ground water elevation data)
20 received by Defendant during the past month and an identification of the source of the sample
21 in both printed and electronic formats; and
22 F. A list of deliverables for the upcoming month if different from the schedule.
23 All Progress Reports shall be submitted in electronic format by the fifteenth (15th) day of
24 the month in which they are due after the effective date of this Decree. Unless otherwise
CONSENT DECREE RE: 13 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 specified, documents submitted pursuant to this Decree shall be sent by certified mail, return
2 receipt requested, to Ecology's project coordinator.
3 XII. RETENTION OF RECORDS
4 During the pendency of this Decree, and for ten (10) years from the date this Decree is
5 no longer in effect as provided in Section XXVIII (Duration of Decree), Defendant shall preserve
6 all records, reports, documents, and underlying data in its possession relevant to the
7 implementation of this Decree and shall insert a similar record retention requirement into all
8 contracts with project contractors and subcontractors. Upon request of Ecology, Defendant shall
9 make all records available to Ecology and allow access for review within a reasonable time.
10 Nothing in this Decree is intended by Defendant to waive any right it may have under
11 applicable law to limit disclosure of documents protected by the attorney work-product privilege
12 and/or the attorney-client privilege. If Defendant withholds any requested records based on an
13 assertion of privilege, Defendant shall provide Ecology with a privilege log specifying the
14 records withheld and the applicable privilege. No Site-related data collected pursuant to this
15 Decree shall be considered privileged.
16 XIII. TRANSFER OF INTEREST IN PROPERTY
17 No voluntary conveyance or relinquishment of title, easement, leasehold, or other interest
18 in any portion of the Site shall be consummated by Defendant without provision for continued
19 operation and maintenance of any containment system, treatment system, and/or monitoring
20 system installed or implemented pursuant to this Decree.
21 Prior to Defendant's transfer of any interest in all or any portion of the Site, and during
22 the effective period of this Decree, Defendant shall provide a copy of this Decree to any
23 prospective purchaser, lessee, transferee, assignee, or other successor in said interest; and, at
24 least thirty (30) days prior to any transfer, Defendant shall notify Ecology of said transfer. Upon
25 transfer of any interest, Defendant shall notify all transferees of the restrictions on the activities
CONSENT DECREE RE: 14 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 and uses of the property under this Decree and incorporate any such use restrictions into the
2 transfer documents.
3 XIV. RESOLUTION OF DISPUTES
4 A. In the event that Defendant elects to invoke dispute resolution, Defendant must
5 utilize the procedure set forth below.
6 1. Upon the triggering event (receipt of Ecology's project coordinator's
7 written decision or an itemized billing statement), Defendant has fourteen (14) calendar
8 days within which to notify Ecology's project coordinator in writing of its dispute
9 ("Informal Dispute Notice").
10 2. The Parties' project coordinators shall then confer in an effort to resolve
11 the dispute informally. The parties shall informally confer for up to fourteen (14)
12 calendar days from receipt of the Informal Dispute Notice. If the project coordinators
13 cannot resolve the dispute within those 14 calendar days, then within seven (7) calendar
14 days Ecology's project coordinator shall issue a written decision ("Informal Dispute
15 Decision") stating: the nature of the dispute; the Defendant's position with regards to
16 the dispute; Ecology's position with regards to the dispute; and the extent of resolution
17 reached by informal discussion.
18 3. Defendant may then request regional management review of the dispute.
19 This request ("Formal Dispute Notice") must be submitted in writing to the Northwest
20 Region Toxics Cleanup Section Manager within seven (7) calendar days of receipt of
21 Ecology's Informal Dispute Decision. The Formal Dispute Notice shall include a written
22 statement of dispute setting forth: the nature of the dispute; the disputing Party's position
23 with respect to the dispute; and the information relied upon to support its position.
CONSENT DECREE RE: 15 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 4. The Section Manager shall conduct a review of the dispute and shall issue
2 a written decision regarding the dispute ("Decision on Dispute") within thirty (30)
3 calendar days of receipt of the Formal Dispute Notice.
4 5. If Defendant finds Ecology's Regional Section Manager's decision
5 unacceptable, Defendant may then request final management review of the decision.
6 This request ("Final Review Request") shall be submitted in writing to the Toxics
7 Cleanup Program Manager within seven (7) calendar days of Defendant's receipt of the
8 Decision on Dispute. The Final Review Request shall include a written statement of
9 dispute setting forth: the nature of the dispute; the disputing Party's position with respect
10 to the dispute; and the information relied upon to support its position.
11 6. Ecology's Toxics Cleanup Program Manager shall conduct a review of
12 the dispute and shall issue a written decision regarding the dispute ("Final Decision on
13 Dispute") within thirty (30) calendar days of receipt of the Final Review Request. The
14 Toxics Cleanup Program Manager's decision shall be Ecology's final decision on the
15 disputed matter.
16 B. If Ecology's Final Decision on Dispute is unacceptable to Defendant, Defendant
17 has the right to submit the dispute to the Court for resolution. The Parties agree that one judge
18 should retain jurisdiction over this case and shall, as necessary, resolve any dispute arising under
19 this Decree. In the event Defendant presents an issue to the Court for review, the Court shall
20 review the action or decision of Ecology on the basis of whether such action or decision was
21 arbitrary and capricious and render a decision based on such standard of review.
22 C. The Parties agree to only utilize the dispute resolution process in good faith and
23 agree to expedite, to the extent possible, the dispute resolution process whenever it is used.
24 Where either party utilizes the dispute resolution process in bad faith or for purposes of delay,
25 the other party may seek sanctions.
CONSENT DECREE RE: 16 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 D. Implementation of these dispute resolution procedures shall not provide a basis
2 for delay of any activities required in this Decree, unless Ecology agrees in writing to a schedule
3 extension or the Court so orders.
4 E. In case of a dispute, failure to either proceed with the work required by this
5 Decree or timely invoke dispute resolution may result in Ecology's determination that
6 insufficient progress is being made in preparation of a deliverable, and may result in Ecology
7 undertaking the work under Section XXV (Implementation of Remedial Action).
8 XV. AMENDMENT OF DECREE
9 The project coordinators may agree to minor changes to the work to be performed
10 without formally amending this Decree. Minor changes will be documented in writing by
11 Ecology.
12 Substantial changes to the work to be performed shall require formal amendment of this
13 Decree. This Decree may only be formally amended by a written stipulation among the Parties
14 that is entered by the Court, or by order of the Court. Such amendment shall become effective
15 upon entry by the Court. Agreement to amend the Decree shall not be unreasonably withheld
16 by any party.
17 Defendant shall submit a written request for amendment to Ecology for approval.
18 Ecology shall indicate its approval or disapproval in writing and in a timely manner after the
19 written request for amendment is received. If the amendment to the Decree is a substantial
20 change, Ecology will provide public notice and opportunity for comment. Reasons for the
21 disapproval of a proposed amendment to the Decree shall be stated in writing. If Ecology does
22 not agree to a proposed amendment, the disagreement may be addressed through the dispute
23 resolution procedures described in Section XIV (Resolution of Disputes).
CONSENT DECREE RE: 17 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 XVI. EXTENSION OF SCHEDULE
2 A. An extension of schedule shall be granted only when a request for an extension
3 is submitted in a timely fashion, generally at least thirty (30) days prior to expiration of the
4 deadline for which the extension is requested, and good cause exists for granting the extension.
5 All extensions shall be requested in writing. The request shall specify:
6 1. The deadline that is sought to be extended;
7 2. The length of the extension sought;
8 3. The reason(s) for the extension; and
9 4. Any related deadline or schedule that would be affected if the extension
10 were granted.
11 B. The burden shall be on Defendant to demonstrate to the satisfaction of Ecology
12 that the request for such extension has been submitted in a timely fashion and that good cause
13 exists for granting the extension. Good cause may include, but may not be limited to:
14 1. Circumstances beyond the reasonable control and despite the due
15 diligence of Defendant including delays caused by unrelated third parties or Ecology,
16 such as (but not limited to) delays by Ecology in reviewing, approving, or modifying
17 documents submitted by Defendant;
18 2. Acts of God, including fire, flood, blizzard, extreme temperatures, storm,
19 or other unavoidable casualty; or
20 3. Endangerment as described in Section XVII (Endangerment).
21 However, neither increased costs of performance of the terms of this Decree nor changed
22 economic circumstances shall be considered circumstances beyond the reasonable control of
23 Defendant.
24 C. Ecology shall act upon any written request for extension in a timely fashion.
25 Ecology shall give Defendant written notification of any extensions granted pursuant to this
CONSENT DECREE RE: 18 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 Decree. A requested extension shall not be effective until approved by Ecology or, if required,
2 by the Court. Unless the extension is a substantial change, it shall not be necessary to amend
3 this Decree pursuant to Section XV (Amendment of Decree) when a schedule extension is
4 granted.
5 D. An extension shall only be granted for such period of time as Ecology determines
6 is reasonable under the circumstances. Ecology may grant schedule extensions exceeding ninety
7 (90) days only as a result of:
8 1. Delays in the issuance of a necessary permit which was applied for in a
9 timely manner;
10 2. Other circumstances deemed exceptional or extraordinary by Ecology; or
11 3. Endangerment as described in Section XVII (Endangerment).
12 XVII. ENDANGERMENT
13 In the event Ecology determines that any activity being performed at the Site under this
14 Decree is creating or has the potential to create a danger to human health or the environment,
15 Ecology may direct Defendant to cease such activities for such period of time as it deems
16 necessary to abate the danger. Defendant shall immediately comply with such direction.
17 In the event Defendant determines that any activity being performed at the Site under
18 this Decree is creating or has the potential to create a danger to human health or the environment,
19 Defendant may cease such activities. Defendant shall notify Ecology's project coordinator as
20 soon as possible, but no later than twenty-four (24) hours after making such determination or
21 ceasing such activities. Upon Ecology's direction, Defendant shall provide Ecology with
22 documentation of the basis for the determination or cessation of such activities. If Ecology
23 disagrees with Defendant's cessation of activities, it may direct Defendant to resume such
24 activities.
CONSENT DECREE RE: 19 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 If Ecology concurs with or orders a work stoppage pursuant to this Section, Defendant's
2 obligations with respect to the ceased activities shall be suspended until Ecology determines the
3 danger is abated, and the time for performance of such activities, as well as the time for any other
4 work dependent upon such activities, shall be extended, in accordance with Section XVI
5 (Extension of Schedule), for such period of time as Ecology determines is reasonable under the
6 circumstances.
7 Nothing in this Decree shall limit the authority of Ecology, its employees, agents, or
8 contractors to take or require appropriate action in the event of an emergency.
9 XVIII. COVENANT NOT TO SUE
10 A. Covenant Not to Sue: In consideration of Defendant's compliance with the terms
11 and conditions of this Decree, Ecology covenants not to institute legal or administrative actions
12 against Defendant regarding the release or threatened release of hazardous substances covered
13 by this Decree.
14 This Decree covers only the Site specifically identified in the Site Diagram (Exhibit A)
15 and those hazardous substances that Ecology knows are located at the Site as of the date of entry
16 of this Decree. This Decree does not cover any other hazardous substance or area. Ecology
17 retains all of its authority relative to any substance or area not covered by this Decree.
18 This Covenant Not to Sue shall have no applicability whatsoever to:
19 1. Criminal liability;
20 2. Liability for damages to natural resources; and
21 3. Any Ecology action, including cost recovery, against PLPs not a party to
22 this Decree.
23 If factors not known at the time of entry of this Decree are discovered and present a
24 previously unknown threat to human health or the environment, the Court shall amend this
25 Covenant Not to Sue.
CONSENT DECREE RE: 20 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 B. Reopeners: Ecology specifically reserves the right to institute legal or
2 administrative action against Defendant to require it to perform additional remedial actions at
3 the Site and to pursue appropriate cost recovery, pursuant to RCW 70.105D.050 under the
4 following circumstances:
5 1. Upon Defendant's failure to meet the requirements of this Decree,
6 including, but not limited to, failure of the remedial action to meet the cleanup standards
7 identified in the Cleanup Action Plan (CAP) (Exhibit B);
8 2. Upon Ecology's determination that remedial action beyond the terms of
9 this Decree is necessary to abate an imminent and substantial endangerment to human
10 health or the environment;
11 3. Upon the availability of new information regarding factors previously
12 unknown to Ecology, including the nature or quantity of hazardous substances at the Site,
13 and Ecology's determination, in light of this information, that further remedial action is
14 necessary at the Site to protect human health or the environment; or
15 4. Upon Ecology's determination that additional remedial actions are
16 necessary to achieve cleanup standards within the reasonable restoration time frame set
17 forth in the CAP (Exhibit B).
18 C. Except in the case of an emergency, prior to instituting legal or administrative
19 action against Defendant pursuant to this section, Ecology shall provide Defendant with fifteen
20 (15) calendar days' notice of such action.
21 XIX. CONTRIBUTION PROTECTION
22 With regard to claims for contribution against Defendant, the Parties agree that
23 Defendant is entitled to protection against claims for contribution for matters addressed in this
24 Decree as provided by RCW 70.105D.040(4)(d).
CONSENT DECREE RE: 21 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 XX. LAND USE RESTRICTIONS
2 In consultation with Defendant, Ecology will prepare the Environmental (Restrictive)
3 Covenant consistent with WAC 173-340-440 and RCW 64.70. After approval by Ecology,
4 Defendant shall record the Environmental (Restrictive) Covenant with the office of the King
5 County Auditor within ten (10) days of the completion of the As-Built Report for each Parcel
6 within the Site. The Environmental (Restrictive) Covenant shall restrict future activities and
7 uses of the Site as agreed to by Ecology and Defendant. Defendant shall provide Ecology with
8 the original recorded Environmental (Restrictive) Covenant within thirty (30) days of the
9 recording date.
10 XXI. FINANCIAL ASSURANCES
11 Pursuant to WAC 173-340-440(11), Defendant shall maintain sufficient and adequate
12 financial assurance mechanisms to cover all costs associated with the operation and maintenance
13 of the remedial action at the Site, including institutional controls, compliance monitoring, and
14 corrective measures.
15 Within sixty (60) days of the effective date of this Decree, Defendant shall submit to
16 Ecology for review and approval an estimate of the costs that it will incur in carrying out the
17 terms of this Decree, including operation and maintenance, and compliance monitoring. Within
18 sixty (60) days after Ecology approves the aforementioned cost estimate, Defendant shall
19 provide proof of financial assurances sufficient to cover all such costs in a form acceptable to
20 Ecology.
21 Defendant shall adjust the financial assurance coverage and provide Ecology's project
22 coordinator with documentation of the updated financial assurance for:
23 A. Inflation, annually, within thirty (30) days of the anniversary date of the entry of
24 this Decree; or if applicable, the modified anniversary date established in accordance with this
CONSENT DECREE RE: 22 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 section, or if applicable, ninety (90) days after the close of Defendant's fiscal year if the financial
2 test or corporate guarantee is used; and
3 B. Changes in cost estimates, within thirty (30) days of issuance of Ecology's
4 approval of a modification or revision to the CAP that result in increases to the cost or expected
5 duration of remedial actions. Any adjustments for inflation since the most recent preceding
6 anniversary date shall be made concurrent with adjustments for changes in cost estimates. The
7 issuance of Ecology's approval of a revised or modified CAP will revise the anniversary date
8 established under this Section to become the date of issuance of such revised or modified CAP.
9 XXII. INDEMNIFICATION
10 Defendant agrees to indemnify and save and hold the State of Washington, its employees,
11 and agents harmless from any and all claims or causes of action (1) for death or injuries to
12 persons or (2) for loss or damage to property to the extent arising from or on account of acts or
13 omissions of Defendant, its officers, employees, agents, or contractors in entering into and
14 implementing this Decree. However, Defendant shall not indemnify the State of Washington
15 nor save nor hold its employees and agents harmless from any claims or causes of action to the
16 extent arising out of the negligent acts or omissions of the State of Washington, or the employees
17 or agents of the State, in entering into or implementing this Decree.
18 XXIII. COMPLIANCE WITH APPLICABLE LAWS
19 A. All actions carried out by Defendant pursuant to this Decree shall be done in
20 accordance with all applicable federal, state, and local requirements, including requirements to
21 obtain necessary permits, except as provided in RCW 70.105D.090. The permits or other
22 federal, state or local requirements that the agency has determined are applicable and that are
23 known at the time of entry of this Decree have been identified in the Applicable or Relevant and
24 Appropriate Requirements (Exhibit D).
CONSENT DECREE RE: 23 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 B. Pursuant to RCW 70.105D.090(1), Defendant is exempt from the procedural
2 requirements of RCW 70.94, 70.95, 70.105, 77.55, 90.48, and 90.58 and of any laws requiring
3 or authorizing local government permits or approvals. However, Defendant shall comply with
4 the substantive requirements of such permits or approvals. The exempt permits or approvals and
5 the applicable substantive requirements of those permits or approvals, as they are known at the
6 time of entry of this Decree, Procedurally Exempt Requirements (Exhibit E).
7 Defendant has a continuing obligation to determine whether additional permits or
8 approvals addressed in RCW 70.105D.090(1) would otherwise be required for the remedial
9 action under this Decree. In the event either Ecology or Defendant determines that additional
10 permits or approvals addressed in RCW 70.105D.090(1) would otherwise be required for the
11 remedial action under this Decree, it shall promptly notify the other party of this determination.
12 Ecology shall determine whether Ecology or Defendant shall be responsible to contact the
13 appropriate state and/or local agencies. If Ecology so requires, Defendant shall promptly consult
14 with the appropriate state and/or local agencies and provide Ecology with written documentation
15 from those agencies of the substantive requirements those agencies believe are applicable to the
16 remedial action. Ecology shall make the final determination on the additional substantive
17 requirements that must be met by Defendant and on how Defendant must meet those
18 requirements. Ecology shall inform Defendant in writing of these requirements. Once
19 established by Ecology, the additional requirements shall be enforceable requirements of this
20 Decree. Defendant shall not begin or continue the remedial action potentially subject to the
21 additional requirements until Ecology makes its final determination.
22 C. Pursuant to RCW 70.105D.090(2), in the event Ecology determines that the
23 exemption from complying with the procedural requirements of the laws referenced in
24 RCW 70.105D.090(1) would result in the loss of approval from a federal agency that is necessary
25 for the State to administer any federal law, the exemption shall not apply and Defendant shall
CONSENT DECREE RE: 24 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 comply with both the procedural and substantive requirements of the laws referenced in RCW
2 70.105D.090(1), including any requirements to obtain permits.
3 XXIV. REMEDIAL ACTION COSTS
4 Defendant shall pay to Ecology costs incurred by Ecology pursuant to this Decree and
5 consistent with WAC 173-340-550(2). These costs shall include work performed by Ecology or
6 its contractors for, or on, the Site under RCW 70.105D, including remedial actions and Decree
7 preparation, negotiation, oversight and administration. These costs shall include work
8 performed both prior to and subsequent to the entry of this Decree. Ecology's costs shall include
9 costs of direct activities and support costs of direct activities as defined in WAC 173-340-550(2).
10 Ecology has accumulated $11,078.12 in unpaid remedial action costs related to this facility
11 incurred under Agreed Order No. DE 6703 as of March 31, 2015. Payment for this amount shall
12 be submitted within thirty (30) days of the effective date of this Decree or by the due date of the
13 invoice for those costs. For all costs incurred subsequent to March 31, 2015, Defendant shall
14 pay the required amount within thirty (30) days of receiving from Ecology an itemized statement
15 of costs that includes a summary of costs incurred, an identification of involved staff, and the
16 amount of time spent by involved staff members on the project. A general statement of work
17 performed will be provided upon request. Itemized statements shall be prepared quarterly.
18 Pursuant to WAC 173-340-550(4), failure to pay Ecology's costs within ninety (90) days of
19 receipt of the itemized statement of costs will result in interest charges at the rate of twelve
20 percent (12%) per annum, compounded monthly.
21 In addition to other available relief, pursuant to RCW 70.105D.055, Ecology has
22 authority to recover unreimbursed remedial action costs by filing a lien against real property
23 subject to the remedial actions.
CONSENT DECREE RE: 25 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 XXV. IMPLEMENTATION OF REMEDIAL ACTION
2 If Ecology determines that Defendant has failed without good cause to make sufficient
3 progress or failed to implement the remedial action, in whole or in part, Ecology may, after
4 notice to Defendant, perform any or all portions of the remedial action or at Ecology's discretion
5 allow the Defendant opportunity to correct. If Ecology performs all or po rtions of the remedial
6 action because of Defendant's failure to comply with its obligations under this Decree, Defendant
7 shall reimburse Ecology for the costs of doing such work in accordance with Section XXIV
8 (Remedial Action Costs), provided that Defendant is not obligated under this section to
9 reimburse Ecology for costs incurred for work inconsistent with or beyond the scope of this
10 Decree.
11 Except where necessary to abate an emergency situation, Defendant shall not perform
12 any remedial actions at the Site outside those remedial actions required by this Decree, unless
13 Ecology concurs, in writing, with such additional remedial actions pursuant to Section XV
14 (Amendment of Decree).
15 XXVI. PERIODIC REVIEW
16 As remedial action, including groundwater monitoring, continues at the Site, the Parties
17 agree to review the progress of remedial action at the Site, and to review the data accumulated
18 as a result of monitoring the Site as often as is necessary and appropriate under the
19 circumstances. At least every five (5) years after the initiation of cleanup action at the Site the
20 Parties shall meet to discuss the status of the Site and the need, if any, for further remedial action
21 at the Site. At least ninety (90) days prior to each periodic review, Defendant shall submit a
22 report to Ecology that documents whether human health and the environment are being protected
23 based on the factors set forth in WAC 173-340-420(4). Under Section XVIII (Covenant Not to
24 Sue), Ecology reserves the right to require further remedial action at the Site under appropriate
25 circumstances. This provision shall remain in effect for the duration of this Decree.
CONSENT DECREE RE: 26 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 XXVII. PUBLIC PARTICIPATION
2 A Public Participation Plan is required for this Site. Ecology shall review any existing
3 Public Participation Plan to determine its continued appropriateness and whether it requires
4 amendment.
5 Ecology shall maintain the responsibility for public participation at the Site. However,
6 Defendant shall cooperate with Ecology, and shall:
7 A. If agreed to by Ecology, develop appropriate mailing lists, prepare drafts of public
8 notices and fact sheets at important stages of the remedial action, such as the submission of work
9 plans, remedial investigation/feasibility study reports, cleanup action plans, and engineering
10 design reports. As appropriate, Ecology will edit, finalize, and distribute such fact sheets and
11 prepare and distribute public notices of Ecology's presentations and meetings.
12 B. Notify Ecology's project coordinator prior to the preparation of all press releases
13 and fact sheets, and before major meetings with the interested public and local governments.
14 Likewise, Ecology shall notify Defendant prior to the issuance of all press releases and fact
15 sheets, and before major meetings with the interested public and local governments. For all press
16 releases, fact sheets, meetings, and other outreach efforts by Defendant that do not receive prior
17 Ecology approval, Defendant shall clearly indicate to its audience that the press release, fact
18 sheet, meeting, or other outreach effort was not sponsored or endorsed by Ecology.
19 C. When requested by Ecology, participate in public presentations on the progress
20 of the remedial action at the Site. Participation may be through attendance at public meetings to
21 assist in answering questions, or as a presenter.
22 D. When requested by Ecology, arrange and/or continue information repositories at
23 the following locations:
24
25 1. Burien Public Library
26 400 S.W. 152nd street
27 Burien, WA 98166
28 (206) 243-3490
CONSENT DECREE RE: 27 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 2. Ecology's Northwest Regional Office
2 3190 160th Avenue SE
3 Bellevue, WA 98008-5452
4 (425) 649-7190
5 At a minimum, copies of all public notices, fact sheets, and documents relating to public
6 comment periods shall be promptly placed in these repositories. A copy of all documents related
7 to this site shall be maintained in the repository at Ecology's Northwest Regional Office in
8 Bellevue, Washington.
9 XXVIII. DURATION OF DECREE
10 The remedial program required pursuant to this Decree shall be maintained and continued
11 until Defendant has received written notification from Ecology that the requirements of this
12 Decree have been satisfactorily completed. This Decree shall remain in effect until dismissed
13 by the Court. When dismissed, Section XVIII (Covenant Not to Sue) and Section XIX
14 (Contribution Protection) shall survive.
15 XXIX. CLAIMS AGAINST THE STATE
16 Defendant hereby agrees that it will not seek to recover any costs accrued in
17 implementing the remedial action required by this Decree from the State of Washington or any
18 of its agencies; and further, that Defendant will make no claim against the State Toxics Control
19 Account or any local Toxics Control Account for any costs incurred in implementing this Decree.
20 Except as provided above, however, Defendant expressly reserves its right to seek to recover
21 any costs incurred in implementing this Decree from any other PLP. This Section does not limit
22 or address funding that may be provided under WAC 173-322.
23 XXX. EFFECTIVE DATE
24 This Decree is effective upon the date it is entered by the Court.
CONSENT DECREE RE: 28 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
1 XXXI. WITHDRAWAL OF CONSENT
2 If the Court withholds or withdraws its consent to this Decree, it shall be null and void at
3 the option of any party and the accompanying Complaint shall be dismissed without costs and
4 without prejudice. In such an event, no party shall be bound by the requirements of this Decree.
5 STATE OF WASHINGTON Robert W. Ferguson
6 DEPARTMENT OF ECOLOGY Attorney General
7
8
9
10 James J. Pendowski Ivy Anderson, WSBA #30652
11 Program Manager Assistant Attorney General
12 Toxics Cleanup Program (360) 586-4619
13 (360) 407-7177
14
15 Date: Date:
16
17
18 PORT OF SEATTLE
19
20
21
22 Theodore J. Fick
23 Chief Executive Officer
24 (206) 728-3000
25
26 Date:
27
28 ENTERED this _____ day of ________________ 20____.
29
30
31 JUDGE
32 King County Superior Court
CONSENT DECREE RE: 29 ATTORNEY GENERAL OF WASHINGTON
Ecology Division
LORA LAKE APARTMENTS SITE
PO Box 40117
Olympia, WA 98504-0117
FAX (360) 586-6760
Exhibit A
Site Diagram
1,271,500 1,272,000 1,272,500 1,273,000 1,273,500
Legend
N
Lora Lake Apartments Site Extent E
I C
R A
U T
SR 518
00 3
0
0 B A
City Boundary
5, 0 00
E
F
5, 0 S
O
F
17
Notes: Y 17
O
T
City boundary data provided by King County. I Y
C
T
Aerial image provided by Port of Seattle I
C
and dated March 20, 2011.
Coordinate grid presented in NAD 1983 HARN
State Plane Coordinate System, Washington
North Zone, in units of Survey Feet.
Lora Lake
Apartments Parcel 1982 Dredged Material
Lora Lake C on tainment Area
Shallow Soil
SOUTH 150TH STREET
00 00
17 4, 5 4, 5
E
17
V
I
R
OU TH
D
L
A
I
S
R Lora Lake
VE O
M
TH 8 A PORT OF
E Shallow Soil
M SEATTLE
S
E
N PROPERTY
I
O
M
S
E
D L o r a
PORT OF L a k e
SEATTLE
PROPERTY
STIA 3RD RUNWAY
N
E
I
APPROACH
C
R A LIGHTING SYSTEM
U T
B A
E
F
S
O
F
Y
00 O
T 00 4, 0
I Y
4, 0 C
T
I
17 C 17
0 150 300
Scale in Feet
Consent Decree Exhibit A
Figure 1
Lora Lake Apartments Site
Site Diagram
Burien, Washington
I:\GIS\Projects\POS_LLA\MXD\CleanupActionPlan - T1140\Figure 1 Site Diagram.mxd
4/14/2015 REVISED DRAFT
Exhibit B
Cleanup Action Plan
Washington State
Department of Ecology Lora Lake Apartments Site
Table of Contents
1.0 Introduction ...................................................................................................... 1-1
2.0 Site Description, Background, and Characterization ................................... 2-1
2.1 SITE DESCRIPTION ........................................................................................2-1
2.1.1 Lora Lake Apartments Parcel .............................................................2-1
2.1.2 Lora Lake Parcel ................................................................................2-2
2.1.3 1982 Dredged Material Containment Area ..........................................2-3
2.2 HISTORICAL PROPERTY OWNERSHIP AND LAND USE ..............................2-4
2.3 REGIONAL AND SITE GEOLOGY ...................................................................2-4
2.4 REGIONAL AND SITE GROUNDWATER.........................................................2-5
3.0 Contaminants of Concern, Cleanup Standards, and Contaminant
Distribution ...................................................................................................... 3-1
3.1 CONTAMINANTS OF CONCERN ....................................................................3-1
3.2 CLEANUP STANDARDS ..................................................................................3-2
3.2.1 Soil Cleanup Levels ............................................................................3-4
3.2.2 Groundwater Cleanup Levels .............................................................3-7
3.2.3 Points of Compliance ..........................................................................3-8
3.3 CONTAMINANT DISTRIBUTION ......................................................................3-9
3.3.1 Soil ...................................................................................................3-10
3.3.2 Groundwater .....................................................................................3-11
3.3.3 Lora Lake Sediment .........................................................................3-12
4.0 Cleanup Areas ................................................................................................. 4-1
4.1 LORA LAKE APARTMENTS PARCEL CLEANUP AREAS ...............................4-1
4.1.1 Cleanup Area A ..................................................................................4-1
4.1.2 Cleanup Area B ..................................................................................4-2
4-4.1.3 Cleanup Area C ..................................................................................4-2
4.2 LORA LAKE PARCEL CLEANUP AREAS ........................................................4-3
4.2.1 Shallow Soil Cleanup Area .................................................................4-3
4.2.2 Sediment Cleanup Area......................................................................4-4
5.0 Selected Remedy ............................................................................................. 5-1
5.1 LORA LAKE APARTMENTS PARCEL ..............................................................5-1
5.2 LORA LAKE PARCEL .......................................................................................5-3
5.3 1982 DREDGED MATERIAL CONTAINMENT AREA .......................................5-6
Revised Draft Cleanup Action Plan
Page i
76860083.1 0061365-00043
Washington State
Department of Ecology Lora Lake Apartments Site
6.0 Selected Remedy Implementation ................................................................. 6-1
6.1 LORA LAKE APARTMENTS PARCEL REMEDY IMPLEMENTATION .............6-1
6.1.1 Soil .....................................................................................................6-1
6.1.2 Groundwater .......................................................................................6-1
6.1.3 Stormwater Conveyance System Improvements ................................6-2
6.1.4 Environmental Covenants ...................................................................6-3
6.2 LORA LAKE PARCEL REMEDY IMPLEMENTATION ......................................6-3
6.2.1 Shallow Soil Cleanup Area .................................................................6-3
6.2.2 Sediment Cleanup Area (Future Wetland) ..........................................6-4
6.2.3 Environmental Covenants ...................................................................6-5
6.3 1982 DREDGED MATERIAL CONTAINMENT AREA REMEDY
IMPLEMENTATION ..........................................................................................6-5
6.3.1 Environmental Covenants ...................................................................6-5
6.4 ENVIRONMENTAL ANALYSIS OF REMEDY IMPLEMENTATION...................6-6
6.5 COMPLIANCE MONITORING ..........................................................................6-6
6.5.1 Lora Lake Apartments Parcel Soil Excavation and DMCA
Consolidation ......................................................................................6-6
6.5.2 Lora Lake Parcel Shallow Soil Cleanup Area Excavation ...................6-7
6.5.3 Groundwater .......................................................................................6-8
6.5.4 Lora Lake Parcel Sediment Cleanup Area (Future Wetland
Soils) ..................................................................................................6-8
6.6 REQUIRED FOLLOW-ON DOCUMENTATION ..............................................6-10
6.6.1 Financial Assurances .......................................................................6-10
6.6.2 Plans Describing the Cleanup Action ................................................6-10
6.6.3 Permits, Approvals, and Substantive Requirements .........................6-11
6.6.4 Construction Documentation ............................................................6-12
6.6.5 Compliance Monitoring Plan .............................................................6-12
7.0 Schedule .......................................................................................................... 7-1
7.1 IMPLEMENTATION SCHEDULE ......................................................................7-1
7.2 CONSTRUCTION PHASING AND SEQUENCING ...........................................7-1
8.0 References ....................................................................................................... 8-1
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List of Tables
Table 3.1 Soil and Groundwater Cleanup Levels
Table 5.1 Cleanup Alternatives Considered for the Lora Lake Apartments Parcel
Table 5.2 Cleanup Alternatives Considered for the Lora Lake Parcel
List of Figures
Figure 1.1 Site Vicinity Map
Figure 2.1 Site Area Map
Figure 2.2 Site Topography
Figure 2.3 Miller Creek Watershed Map
Figure 2.4 Historical Site Uses and Operations
Figure 3.1 Points of Compliance
Figure 3.2 Summary of Contaminant Distribution
Figure 3.3 Excavation Volume by Soil Concentration
Figure 4.1 Lora Lake Apartments Parcel Cleanup Areas
Figure 4.2 Lora Lake Parcel Cleanup Areas
Figure 5.1 Lora Lake Apartments Parcel Alternative Cost vs. Percent Dioxins/Furans
Mass Removed
Figure 5.2 Lora Lake Apartments Parcel and Lora Lake Parcel Soil Dioxins/Furans
TEQ Concentrations to Remain On-site Compared to Dioxins/Furans TEQ
Concentrations in Seattle Urban Soil
Figure 6.1 Conceptual Remedy Cross Section
List of Appendices
Appendix A SEPA Documents
List of Acronyms and Abbreviations
Acronym/
Abbreviation Definition
AO Agreed Order
bgs Below ground surface
BMP Best Management Practices
CAA Controlled Activity Area
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Acronym/
Abbreviation Definition
CFR Code of Federal Regulations
COC Contaminant of concern
cPAH Carcinogenic polycyclic aromatic hydrocarbon
DCAP Draft Cleanup Action Plan
DMCA 1982 Dredged Material Containment Area
EIC Ecological Indicator (soil) Concentration
Ecology Washington State Department of Ecology
FAA Federal Aviation Administration
LL Apartments Parcel Lora Lake Apartments Parcel
LL Parcel Lora Lake Parcel
g/kg Micrograms per kilogram
g/L Micrograms per liter
mg/kg Milligrams per kilogram
MTCA Model Toxics Control Act
NRMP Natural Resource Management Plan
PCP Pentachlorophenol
pg/g Picograms per gram
pg/L Picograms per liter
POC Point of compliance
Port Port of Seattle
RCW Revised Code of Washington
RI Remedial Investigation
RI/FS Remedial Investigation/Feasibility Study
RPZ Runway Protection Zone
SEPA State Environmental Policy Act
Site Lora Lake Apartments Site
SR 518 State Route 518
STIA Seattle-Tacoma International Airport
TEE Terrestrial Ecological Evaluation
TEQ Toxicity equivalent
USACE U.S. Army Corps of Engineers
WAC Washington Administrative Code
WHMP Wildlife Hazard Management Plan
XOFA Extended Object Free Area
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1.0 Introduction
This Draft Cleanup Action Plan (DCAP) describes the cleanup action selected by the
Washington State Department of Ecology (Ecology) for the Lora Lake Apartments Site
(LL Apartments Site, or Site). The Site is located at 15001 Des Moines Memorial Drive in
Burien, Washington (Figure 1.1), near the northwest corner of Seattle-Tacoma
International Airport (STIA).
This DCAP was developed using information presented in the Remedial
Investigation/Feasibility Study (RI/FS) for the Site, which was prepared by Floyd|Snider
in 2015 (Floyd|Snider 2015a) on behalf of the Port of Seattle (Port) in accordance with
the Agreed Order (AO) for the Site. The Port and Ecology entered into AO No. DE 6703
for the LL Apartments Site on July 10, 2009 (Ecology 2009).
The Site consists of three parcels: (1) Lora Lake Apartments Parcel (LL Apartments
Parcel), (2) Lora Lake Parcel (LL Parcel), and (3) 1982 Dredged Material Containment
Area (DMCA). The site cleanup is expected to occur in phases, with remedial actions
conducted consistent with the schedule provided in Exhibit C of the Consent Decree.
The Lora Lake Apartments Site is being cleaned up under the authority of the Model
Toxics Control Act (MTCA), Chapter 70.105D of the Revised Code of Washington (RCW)
(Ecology, 2007), and the MTCA Cleanup Regulation, Chapter 173-340 of the Washington
Administrative Code (WAC).
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2.0 Site Description, Background, and Characterization
The Site straddles the boundary between the Cities of Burien and SeaTac, Washington
(refer to Figure 2.1). The LL Apartments Parcel is located within the City of Burien, at
15001 Des Moines Memorial Drive. The LL Parcel is located immediately across
Des Moines Memorial Drive to the east, and the DMCA is located to the northeast of the
LL Parcel, both within the City of SeaTac.
The Site, as defined by WAC 173-340-200, consists of the LL Apartments property, and
areas within the LL Parcel and DMCA, where contamination has come to be located. Prior
to the Remedial Investigation (RI) conducted in 2010, environmental investigations at the
Site focused on the property referred to throughout this document as the LL Apartments
Parcel. Investigations and historical research conducted as part of the RI determined that
concentrations of contaminants identified at the LL Apartments Parcel were also present
in soil and sediment on the LL Parcel and the DMCA.
A portion of the LL Apartments Parcel and all of the LL Parcel and the DMCA are within
designated safety zones established for operation of the STIA 3rd Runway (Figure 2.1).
Collectively these zones are called Runway Protection Zones (RPZs). Two subzones
cover the Site, the Extended Object Free Area (XOFA) and the Controlled Activity Area
(CAA). The XOFA must be kept clear of objects (including structures, equipment, and
terrain), with the exception of objects necessary for air navigation or aircraft groundmaneuvering
purposes. The CAA is farther from the runway; however, construction of
residences and public gathering places, such as shopping centers, offices, or hospitals
may not be constructed in the CAA. The Port will own the land within the RPZs in
perpetuity. Residential land use is not a potential future use within the RPZs.
2.1 SITE DESCRIPTION
2.1.1 Lora Lake Apartments Parcel
The LL Apartments Parcel occupies approximately 8.3 acres of currently vacant land that
is bounded to the north by State Route 518 (SR 518), to the east and southeast by
Des Moines Memorial Drive, to the west by 8th Avenue South, and to the south by an
open area that was formerly the site of a grocery store, bowling alley, small office
complex, and the former Seattle City Light Sunnydale Substation (shown on Figure 2.1
as the Former Seattle City Light Property), purchased by the Port in 2011. Land use to
the west of the LL Apartments Parcel is primarily residential. The area of the STIA located
just southeast of Des Moines Memorial Drive is reserved for habitat mitigation associated
with development of the STIA 3rd Runway and for the eastbound onramp to SR 518. The
LL Apartments Parcel vacant land is currently covered by asphalt parking areas, concrete
building foundations, and landscaping areas remaining from the previous LL Apartments
complex. The apartment buildings were demolished by the Port in 2009. The existing
LL Apartments Parcel topography was created during construction of the apartment
buildings in 1987. The LL Apartments Parcel topography slopes gradually to the
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southeast, with steeper slopes located adjacent to Des Moines Memorial Drive to the east
and from the SR 518 embankment to the north, as shown on Figure 2.2. To the southeast
of the existing property boundary, the topography continues to slope gradually to the east
towards Lora Lake.
An active City of Burien stormwater system currently runs through the LL Apartments
Parcel, including a main stormwater line that conveys stormwater drainage from the
upstream City of Burien drainage network (the Main Line). This main stormwater line
enters on the west side of the LL Apartments Parcel and exits on the east side of the
parcel. A second, smaller sub-system drains the northeast portion of the LL Apartments
Parcel and conveys water through smaller pipes (the Secondary Line). The two systems
connect to the adjacent Des Moines Memorial Drive drainage system downstream of the
property and discharge, with the additional stormwater from Des Moines Memorial Drive,
to Lora Lake through an outfall located at the northwestern edge of the lake.
Stormwater chemical quality was assessed during the RI at multiple locations within the
interior of the LL Apartments Parcel as well as where the City of Burien main stormwater
line enters and exits the parcel (i.e., the Main Line Inlet and Outlet), and where the
secondary line exits the parcel (the Secondary Line Outlet). The assessment found that
(1) upon entry to the LL Apartments Parcel, the City of Burien's stormwater contained
multiple Contaminants of Concern (COCs), including dioxins/furans, and (2) stormwater
from the LL Apartments Parcel was not contributing to degradation of the stormwater
conveyed from upstream across the property (refer to Appendix E of the RI/FS).
2.1.2 Lora Lake Parcel
The LL Parcel is located to the southeast of the LL Apartments Parcel, on the east side
of Des Moines Memorial Drive. The LL Parcel consists of approximately 7.1 acres of land,
including the approximately 3-acre Lora Lake and a STIA-constructed wetland aquatic
habitat mitigation area. The LL Parcel is bounded to the north by the SR 518 highway
interchange, to the east and south by Port-owned habitat mitigation area and the northern
boundary of the STIA air operations area, and to the west and northwest by Des Moines
Memorial Drive (Figure 2.1). The LL Parcel and surrounding areas are located within the
Miller Creek Watershed. Headwaters of Miller Creek flow south (from north of STIA) along
the west side of the airport, through a series of Port-owned habitat mitigation properties
(including the LL Parcel), before turning west, crossing below Highway 509, and
eventually draining to Puget Sound. Figure 2.3 shows the location of Lora Lake in relation
to Miller Creek and the Miller Creek Watershed.
The LL Parcel lies within a series of habitat mitigation areas developed and enhanced by
the Port in compliance with requirements of the Clean Water Act Section 404 Permit
#1996-4-02325 issued by the U.S. Army Corps of Engineers (USACE) to support aquatic,
amphibian, and wetland habitat as part of the mitigation requirements associated with
development of the STIA 3rd Runway in 1997 (Port of Seattle 2011). The mitigation area
is designated in the Natural Resource Management Plan (NRMP) as the Miller
Creek/Lora Lake/Vacca Farm Wetland and Floodplain Mitigation Area (Parametrix 2001).
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The LL Parcel is densely vegetated and contains a mixture of grasses, forbs, emergent
wetland plants, and a canopy of mixed deciduous trees. Surface water bodies associated
with the LL Parcel consist of Lora Lake and Miller Creek, which runs past the southeast
margin of Lora Lake.
The operation and maintenance requirements for the Miller Creek/Lora Lake/Vacca Farm
Wetland and Floodplain Mitigation Area are described in the NRMP (Parametrix 2001).
The mitigation plan requirements support specific ecological functions, but these are
managed within the context of the Port's Wildlife Hazard Management Plan (WHMP; Port
of Seattle 2005), the controlling authority for this special-use area. The WHMP provisions
require, and result in, careful control of birds, mammals, and plants within the area to
minimize aircraft navigation dangers associated with bird strikes and wildlife in the runway
area.
Lora Lake currently receives stormwater runoff from the LL Apartments Parcel, the City
of Burien residential and commercial drainage areas upstream of the LL Apartments
Parcel, and the surrounding roadways downstream of the LL Apartments Parcel (e.g.,
Des Moines Memorial Drive, SR 518 interchange, City of SeaTac) through a single outfall
located near the northwestern edge of Lora Lake and via non-point source overland flow
from the LL Parcel.
2.1.3 1982 Dredged Material Containment Area
The DMCA, presented on Figure 2.1, is located adjacent to the LL Parcel, to the northeast,
on Port property. The DMCA is located within the secured airport area, the RPZ-XOFA,
within security fencing and is monitored and access-controlled by Port security. Entry by
the public is prohibited.
The City of Burien stormwater system that currently crosses the LL Apartments Parcel
discharges from an outfall in the northwest corner of Lora Lake, as described above. In
1982, in response to complaints from residents around the lake regarding excessive
siltation caused by this stormwater discharge, the then-current owner of the system,
King County, agreed to dredge approximately 4 feet of sediment from the lake bottom.
King County arranged with the Port to place the dredge material in a specifically
constructed facility on Port-owned property to the northeast of Lora Lake. The historical
project plans for the dredging work indicate that a total of 16,000 cubic yards of material
would be dredged, then placed and dewatered inside an approximately
120,000-square-foot area surrounded by a constructed soil berm. The dredging project
was implemented in 1982. The dredge spoil containment area is now referred to as the
DMCA.
The DMCA has an area of approximately 2.75 acres, based on review of aerial
photographs. The eastern half of the DMCA is an approximately 1.5-acre vegetated area
covered by a few trees and a mix of grasses and invasive and pioneering plant species,
including scotch broom, alder saplings, Himalayan blackberry, and butterfly bush. The
remaining approximately 1.25 acres of land is the location of the Approach Lighting
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System for the STIA 3rd Runway, which was constructed in 2006. This area has been
regraded and covered with gravel and is maintained by the Port to be free of vegetation.
The DMCA is located outside of the Miller Creek/Lora Lake/Vacca Farm Wetland and
Floodplain Mitigation Area. It is subject to the WHMP.
2.2 HISTORICAL PROPERTY OWNERSHIP AND LAND USE
Through the 1930s, the area was primarily agricultural, containing family farms, suburban
development, and supporting commercial businesses. Des Moines Memorial Drive has
been a primary thoroughfare since this time. To the east of Des Moines Memorial Drive,
a peat bog was excavated in the 1940s and 1950s to mine the peat, resulting in the
creation of Lora Lake. Houses were built around the lake, which were present through the
late 1990s.
The LL Apartments Parcel property was farmland until the mid-1940s, when the Novak
Barrel Cleaning Company was established. Metal drums and other containers were
brought to the company for washing in order to prepare the containers for reuse. It is
suspected that barrel drainage and washing activities took place in an operations area
located near the center of the LL Apartments Parcel, where barrel contents appear to
have been released, given the current presence of a clearly defined zone of substantial
contamination. Barrel-washing operations were conducted on the property until the early
1950s, when the property was sold for use as an auto-wrecking yard. The property was
used for auto-wrecking and auto storage until the mid-1980s.
In 1987, apartment buildings were constructed on the property. During development, a
small excavation to remove metals and petroleum-contaminated material was completed
in the area of assumed barrel-washing operations. This excavation and associated
cleanup were reported to and approved by Ecology at the time. Figure 2.4 presents
locations of these known historical site uses and operations at, and directly adjacent to,
the LL Apartments Parcel.
The Port purchased the LL Apartments Parcel property in 1998, as part of the STIA
3rd Runway Project. Concurrently, the Port purchased properties east of Des Moines
Memorial Drive, which also were within the expansion area for the new runway and the
Federal Aviation Administration (FAA) RPZs. These properties included Lora Lake and
its abutting residences. The residences and apartments were demolished by the Port
between approximately 2005 and 2009.
2.3 REGIONAL AND SITE GEOLOGY
Substantial investigations of the regional geology in the area of the Site have been
conducted, including a Port-commissioned STIA Groundwater Study (Aspect Consulting
and S.S. Papadopulos 2008), and were used in the development of the following geology
summary.
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In general, the Puget Lowland is underlain at depth by volcanic and sedimentary bedrock
and is filled to the present-day land surface with both glacial and interglacial sediments
(interglacial sediments are those derived between periods of glaciation) deposited during
the Quaternary Period (within the last 2 million years; Aspect Consulting 2010).
At the LL Apartments Parcel, glacial recessional outwash deposits are present at the
surface in areas where no fill is present. These recessional outwash deposits are part of
a relatively large southwest-northeast trending channel feature. With the exception of the
northern portion of the LL Apartments Parcel, the surface topography across the
remainder of the LL Apartments Parcel reflects substantial regrading that was performed
during construction of the apartment complex.
Data collected from soil borings and monitoring well installations indicate that the
subsurface geology at the LL Apartments Parcel consists of a discontinuous fill layer that
overlays glacial recessional outwash deposits. At the bottom of the recessional outwash
deposits a silt unit about 10 feet thick was encountered in the eastern portion of the
LL Apartments Parcel. Based on the STIA Groundwater Study, this silt unit is likely
indicative of a transition from recessional outwash deposits into glacial till deposits
(Aspect Consulting and S.S. Papadopulos 2008). The fill unit in the vicinity of the
LL Apartments Parcel is observed to have a variable thickness of up to 15 feet but is
absent in the northern portion of the property. The fill is composed of medium dense-todense
, fine-to-coarse grained sand with rounded gravel.
To the southeast of the LL Apartments Parcel, the LL Parcel is also underlain by
recessional outwash deposits, which are exposed at the surface. Beneath the recessional
outwash deposits, it is inferred that the till deposits are also present and create a perching
layer on which Lora Lake and the surrounding wetlands are formed. Three subsurface
sediment cores were collected in Lora Lake to depths of 5.5 feet in two locations, and a
depth of approximately 2 feet in the third location. Sediment types were observed to be
variable between the three sampling locations. Sediment types included sandy silts with
gravels, silts, and a thick reddish-brown peat layer in one of the cores beneath a layer of
silt.
Data collected from test pits advanced to 6 feet below ground surface (bgs) at the DMCA
indicate a similar fill layer to that of the LL Apartments Parcel (i.e., fine-to-coarse grained
sand with some silty sands and gravels). The assumed dredge material horizon was dark
brown silty sand with peaty material.
2.4 REGIONAL AND SITE GROUNDWATER
The uppermost groundwater aquifer in the vicinity of the Site is the recessional outwash
aquifer. Groundwater flow in the recessional outwash aquifer in the vicinity of the
LL Apartments Parcel is to the southeast, towards Lora Lake. Because of the absence of
any confining units within the recessional outwash deposits that prevent groundwater flow
between the recessional outwash aquifer and Lora Lake, and based on the calculated
vertical groundwater gradients, the recessional outwash aquifer is likely in hydraulic
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continuity with Lora Lake. Lora Lake and the predecessor peat-dominated wetland
formation likely formed on top of glacial till deposits that act as a confining unit (aquitard)
beneath the recessional outwash aquifer in the eastern portion of the LL Apartments
Parcel. This aquitard acts as a low-permeability barrier to groundwater flow and limits
downward flow into the deeper glacial advance outwash deposits and regional aquifers.
Groundwater at the LL Apartments Parcel was observed at depths ranging from
approximately 5 to 22 feet bgs in wells within the native recessional outwash deposits
and some fill materials. Groundwater in downgradient wells located just east of Des
Moines Memorial Drive was observed at depths ranging from approximately
10 to 15 feet bgs. Groundwater levels generally responded to an increase in
precipitation, with lower groundwater levels observed in August and higher groundwater
levels observed in January (with the difference ranging between 1 foot and 6 feet).
Groundwater levels in all of the monitoring wells were substantially higher than surface
water levels in Lora Lake and Miller Creek. These data suggest that the surface water
bodies may be "gaining" water from groundwater discharge. Based on both groundwater
elevation contour maps, groundwater flow in the vicinity of the LL Apartments Parcel is
primarily to the southeast, towards Lora Lake, with slightly lower horizontal groundwater
gradients (between 0.008 and 0.017 feet per foot) across the western portion of the LL
Apartments Parcel, compared to the eastern portion of the LL Apartments Parcel
(between 0.044 and 0.051 feet per foot).
The drinking water supply for residences and businesses surrounding the Site is provided
primarily by the Highline Water District's municipal drinking water system. The closest
groundwater supply/extraction wells are located approximately 1 to 2 miles downgradient
and cross-gradient to the Site. These wells are screened in the deeper regional aquifer
units (more than 100 feet bgs) and are unlikely to have hydrologic connection to the
near-surface shallow aquifer (recessional outwash aquifer) because of the presence of
underlying aquitards, including till deposits and, potentially, the fine-grained units of the
transition beds.
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3.0 Contaminants of Concern, Cleanup Standards,
and Contaminant Distribution
COCs, their distribution, and applicable cleanup standards for the LL Apartments Parcel
and the LL Parcel are presented below.
3.1 CONTAMINANTS OF CONCERN
The following COCs were identified in the RI/FS for the Site:
Lora Lake
Contaminant Soil Groundwater Sediment1
Arsenic
Carcinogenic polyaromatic
hydrocarbons
Pentachlorophenol
Dioxins/furans
Total Petroleum Hydrocarbons
(Gasoline, Diesel, and Heavy Oil
Ranges)
Lead
Toluene
Ethylbenzene
These contaminants are consistent with the past site uses, assuming that barrel-washing
residue would contain a variety of chemicals comprising wood-treating compounds,
solvents, and petroleum products.
Dioxins/furans are the most widespread COC at the Site, exceeding the applicable
cleanup level in shallow soil throughout the LL Apartments Parcel, deeper soil within the
1 As described in Section 4.2, the LL Parcel is divided into two clean up areas: the Shallow Soil Cleanup Area and the
Sediment Cleanup Area. The Lora Lake Sediment Cleanup Area encompasses sediments within the lake and extends
to the lake shoreline (approximately 3 acres), and is the only sediment area at the Site. The remedial action to be
implemented to address Lora Lake sediment contamination includes capping and the filling of the open water to
rehabilitate the lake to a palustrine scrub-shrub wetland. Thus, remedy implementation results in the conversion of
existing lake sediment and open water to wetland soil. The wetland will be designed so that water is not present for
more than 6 consecutive weeks. Hence, the wetland surface will not be classified as sediment because it will not
meet the definition of sediment in the Sediment Management Standards (refer to WAC 173-204-505(22)).
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central and eastern source areas of the LL Apartments Parcel, and shallow soil at the
LL Parcel.
The historical releases and operations within the central and eastern source areas of the
LL Apartments Parcel have impacted the shallow groundwater with arsenic,
pentachlorophenol (PCP), and dioxins/furans. Deeper groundwater beneath the
LL Apartments Parcel has not been impacted by contamination.
Shallow groundwater contamination is limited to the LL Apartments Parcel. Groundwater
downgradient of the LL Apartments Parcel, beneath the LL Parcel, and beneath and
downgradient of the DMCA, has not been impacted.
Lora Lake sediment has been impacted by elevated levels of dioxins/furans. Detected
concentrations of arsenic and lead in Lora Lake sediments were greater than Sediment
Cleanup Objective levels, but less than Cleanup Screening Levels as evaluated in the
RI/FS. Biological toxicity testing demonstrated that the sediments would not cause
adverse impacts to benthic organisms.
At the DMCA, reported concentrations of site COCs were less than the applicable
Industrial Cleanup Standards. The Port plans to use the DMCA for equipment storage
and temporary construction laydown. The DMCA surface will be improved by placing a
compacted gravel or an equivalent engineered surface. This will eliminate potential
wildlife exposure pathways and allow for an exclusion from the Terrestrial Ecological
Evaluation (TEE).2
3.2 CLEANUP STANDARDS
Cleanup standards have been established for this Site. Two factors control designation
of appropriate cleanup standards for specific sites: specification of cleanup levels (the
chemical concentrations that are protective of human health and the environment for the
applicable exposure pathways) for each COC in each impacted media; and identification
of the point of compliance (POC; the location on the Site where the cleanup levels must
be attained). Current and future uses and associated exposure pathways are different for
each of the three parcels at the LL Apartments Site, resulting in different soil cleanup
levels for each parcel. Groundwater cleanup levels apply site-wide as demonstrated in
the RI/FS and the Demonstration of Groundwater Protection of Surface Water Beneficial
Uses technical memorandum (Floyd Snider 2015b).
As described in Section 5.2, the remedial action to be implemented to address Lora Lake
sediment contamination includes capping and the filling of the open water to rehabilitate
Lora Lake to a wetland system. This action will result in the conversion of the existing
lake sediment and open water conditions to a palustrine scrub-shrub wetland (as defined
2 The TEE COCs are dioxins/furans. Dioxins/furans do not have cleanup levels applicable to plants or soil biota. There
are cleanup standards for wildlife. Hence, the barrier needs to prevent exposure of wildlife to soil.
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in Cowardin et al. 1979). The scope of the Lora Lake sediment remedy will be based on
the current extent of open water and lake sediments. Once implemented, the remedy will
result in a contiguous wetland on the LL Parcel. The wetland will be designed so that
open water does not occur more than 6 consecutive weeks per year, and, hence, the
wetland surface will be classified as soil as it will not meet the definition of sediment in
the Sediment Management Standards (refer to WAC 173-204-505(22)). Following
remedy implementation, soil and groundwater cleanup levels and associated MTCA
regulations will be applicable to the entire LL Parcel, rather than sediment-based cleanup
levels.
Applicable cleanup standards for each parcel in each media have been identified in the
RI/FS and technical memorandum (Floyd Snider 2015b) and are described below.
In overview, the primary cleanup regulation and guidance that applies to this Site is the
MTCA Cleanup Regulation (Chapter 173-340 WAC). Surface water quality criteria
(National Toxics Rule, 40 Code of Federal Regulations [CFR] 131.36 and Clean Water
Act Section 304) were also considered in determination of groundwater cleanup levels,
evaluating the leaching potential of Lora Lake and Miller Creek sediments, and
conceptual design of the sediment remedial action.
In developing cleanup levels, the following site-specific land use information is relevant:
The Port's current objective for the Site is to redevelop the city block that the
LL Apartments Parcel is a part of for airport-compatible commercial or light
industrial use.
The LL Apartments Parcel, the majority of the LL Parcel, and the DMCA are all
Port-owned properties currently located within security fencing and monitored
and access-controlled by Port security procedures and personnel. Public
access is not allowed. A small portion of the LL Parcel adjacent to Des Moines
Memorial Drive is outside of the secured fencing, is potentially accessible by
the public, and is located on City of SeaTac right-of-way.
The FAA defines restrictions on allowable development and structures for
runway and runway approach safety areas (AC/150 5300-13; USDOT
FAA 1989). Figure 2.1 shows where the FAA's Runway Protection and
Approach Transition Zones overlay the Site. The restrictions are given in the
legend.
The LL Parcel is part of the Miller Creek/Lora Lake Upland Buffer and Flood
Plain Zone Mitigation Area required by the NRMP for STIA 3rd Runway
construction (Parametrix 2001). Lora Lake and Miller Creek are both currently
freshwater environments with public access prohibited in the area surrounding
Lora Lake and the adjacent portions of Miller Creek. Restrictive covenants
prohibit any future development on the LL Parcel, which, following remedy
implementation, will be maintained as a protected wetland habitat area in
perpetuity.
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WAC 173-201A-600(1), a section of the Water Quality Standards for Surface
Waters of the State of Washington, requires that water quality in Miller Creek
be protected for the following: salmonid spawning, rearing, and migration;
primary contact recreation; domestic, industrial, and agricultural water supply;
stock watering; wildlife habitat; harvesting; commerce and navigation; boating;
and aesthetic values. In addition, Miller Creek, to which Lora Lake discharges,
has been closed to consumptive use since 1946 in order to protect flows for
aquatic habitat (Water Resource Inventory Area 9, WAC 173-509-040).
The DMCA meets the MTCA criteria for establishing soil cleanup levels for
industrial land use. COC soil concentrations measured at the DMCA were less
than the soil cleanup standards for industrial properties (WAC 173-340-745).
Groundwater downgradient from the DMCA was not impacted by COCs. The
DMCA qualifies for an exclusion from the TEE due to the Port's planned future
land use. An institutional control will be placed on the DMCA to require that
surface improvements provide a barrier to wildlife and to keep the area in
industrial use.
Table 3.1 summarizes the cleanup levels applicable to the LL Apartments Parcel, the
LL Parcel, and the DMCA following evaluation of the pathways for each media. Table 3.1
also identifies the specific numerical cleanup levels, based on the applicable cleanup
levels by media for each specific COC.
3.2.1 Soil Cleanup Levels
As stated above, each of the three parcels at the LL Apartments Site have different current
and future uses and associated exposure pathways, resulting in differing applicability of
soil cleanup levels, as described below.
3.2.1.1 Lora Lake Apartments Parcel
The following soil exposure pathways and associated cleanup level regulations are
applicable to the LL Apartments Parcel:
Protection of human health via direct contact with soil: MTCA Method B (or
Method A where Method B is not available) soil cleanup levels. MTCA
Method B soil cleanup levels are protective for airport workers and possible
public direct contact exposure.
Soil leaching to groundwater: MTCA Equation 747-1 calculation of soil cleanup
levels for the protection of groundwater resources from contaminants leaching
from soil, unless empirical site data demonstrate that this is not a pathway of
concern.
Protection of ecological receptors: The LL Apartments Parcel meets the criteria
for an exclusion from the TEE because future land use is planned to be airportcompatible
commercial or light industrial use within 4 years of completion of
cleanup construction, thus creating a barrier to wildlife. An institutional control
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will be placed on the LL Apartments Parcel to require that surface
improvements provide a barrier to wildlife and to keep the area in commercial
use.
As shown in Table 3.1, the numeric cleanup levels selected for soil at the LL Apartments
Parcel are:
Dioxins/furans toxicity equivalent (TEQ) = 13 picograms per gram (pg/g)
Arsenic = 20 milligrams per kilogram (mg/kg)
Lead = 250 mg/kg
Gasoline-range hydrocarbons = 100 mg/kg
Sum of diesel and heavy oil range hydrocarbons = 2,000 mg/kg
Pentachlorophenol = 2,500 micrograms per kilogram (g/kg)
Carcinogenic polycyclic aromatic hydrocarbons (cPAHs) TEQ = 137 g/kg
Ethylbenzene = 8,000 mg/kg
Toluene = 6,400 mg/kg
3.2.1.2 Lora Lake Parcel
The following soil exposure pathways and associated cleanup level regulations are
applicable to the LL Parcel:
Protection of human health via direct contact with soil: MTCA Method B (or
Method A where Method B is not available) soil cleanup levels. MTCA
Method B soil cleanup levels are protective for airport workers and possible
public direct contact exposure.
Soil leaching to groundwater: MTCA Equation 747-1 calculation of soil cleanup
levels for the protection of groundwater resources from contaminants leaching
from soil, unless empirical site data demonstrate that this is not a pathway of
concern.
Protection of terrestrial plants and animals: The LL Parcel does not qualify for
an exclusion from the TEE process, and site-specific ecological indicator soil
concentrations (EICs) for plants, avian and mammalian wildlife (WAC 173-340-
900, Table 749-3) are applicable as soil cleanup levels for the ecological COCs.
TEE EICs for wildlife exposure for dioxins and furans (2 pg/g TEQ and 2 pg/g
TEQ, separately) are less than the Ecology-determined State of Washington
natural background soil concentration of 5.2 pg/g TEQ for dioxins/furans
(Ecology 2010). Because MTCA WAC 173-340-900 Table 749-3 states that
"Natural background concentrations may be substituted for ecological indicator
concentrations provided in this table," natural background is applicable as a
soil cleanup level at the LL Parcel for dioxins/furans.
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As shown in Table 3.1, the numeric cleanup levels selected for soil at the LL Parcel are:
Dioxins/furans TEQ = 5.2 pg/g
Arsenic = 20 mg/kg
Lead = 50 mg/kg
Gasoline-range hydrocarbons = 100 mg/kg
Sum of diesel and heavy oil range hydrocarbons = 200 mg/kg
Pentachlorophenol = 2,500 g/kg
cPAHs TEQ = 137 g/kg
Ethylbenzene = 8,000 mg/kg
Toluene = 6,400 mg/kg
3.2.1.3 1982 Dredged Material Containment Area
The following soil exposure pathways and associated cleanup levels are applicable to the
DMCA:
Protection of human health via direct contact with soil: MTCA Method C soil
cleanup levels. MTCA Method C soil cleanup levels are protective for industrial
use and airport worker direct contact exposure.
Soil leaching to groundwater: MTCA Equation 747-1 calculation of soil cleanup
levels for the protection of groundwater resources from contaminants leaching
from soil, unless empirical site data demonstrate that this is not a pathway of
concern.
Protection of terrestrial plants and animals: Future land uses at the DMCA will
be airport-compatible uses in compliance with the FAA RPZs, such as
temporary construction laydown or equipment storage. Land use
improvements to allow for this future use will consist of surface improvements
(e.g., placement of a compacted gravel or engineered surface), which eliminate
potential wildlife exposure pathways and allow for an exclusion from the TEE
and application of cleanup standards for terrestrial and ecological protection at
the DMCA. Institutional controls will be placed on the DMCA to ensure barriers
to wildlife are maintained in the future and to keep the area in industrial use.
As shown in Table 3.1, the numeric cleanup levels selected for soil at the DMCA are:
Dioxins/furans TEQ = 1,700 pg/g
Arsenic = 88 mg/kg
Lead = 1,000 mg/kg
Gasoline-range hydrocarbons = 100 mg/kg
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Sum of diesel and heavy oil range hydrocarbons = 2,000 mg/kg
Pentachlorophenol = 330,000 g/kg
cPAHs TEQ = 18,000 g/kg
Ethylbenzene = 350,000 mg/kg
Toluene = 280,000 mg/kg
3.2.2 Groundwater Cleanup Levels
The following groundwater exposure pathways and associated cleanup level regulations
were evaluated for applicability to groundwater throughout the Site:
Protection of human health via drinking water consumption: MTCA Method B
(or Method A where Method B is not available) groundwater cleanup levels.
Protection of human health via drinking water consumption: state and federal
drinking water Maximum Contaminant Levels.
Protection of surface water beneficial uses.
Applicability of surface water quality criteria was evaluated in the RI/FS and in a technical
memorandum (Floyd Snider 2015b). Surface water quality criteria are based on protection
of human health via consumption of aquatic organisms. For all site COCs, except
dioxins/furans, groundwater cleanup levels based on drinking water consumption are
more stringent than these surface water criteria. Therefore, evaluation of the applicability
of surface water quality criteria was limited to dioxins/furans.
Assessment of dioxins/furans concentrations in groundwater at the LL Apartments Parcel
is discussed in Section 5.2.2.2 of the RI/FS. Assessment of dioxins/furans in groundwater
at the LL Parcel is discussed in a technical memorandum (Floyd|Snider 2015b). These
assessments demonstrate dioxins/furans present in groundwater at the Site are not likely
to reach surface water. WAC 173-340-720(4)(b)(ii) states that,
"Where the groundwater cleanup level is based on a drinking water
beneficial use, standard MTCA Method B cleanup levels shall be at least as
stringent as concentrations established in accordance with the methods
specified in WAC 173-340-730 for protecting surface water beneficial uses
unless it can be demonstrated that the hazardous substances are not likely
to reach surface water. This demonstration must be based on factors other
than the implementation of a cleanup action at the site."
Hence, the applicable groundwater cleanup level for dioxins/furans throughout the Site is
based on protection of human health via drinking water consumption.
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As shown in Table 3.1, the numeric cleanup levels for groundwater throughout the Site
are:
Dioxins/furans TEQ = 6.7 picograms per liter (pg/L)
Arsenic = 5 micrograms per liter (g/L)
Gasoline-range hydrocarbons = 1,000 g/L
Sum of diesel and heavy oil range hydrocarbons = 500 g/L
Pentachlorophenol = 1 g/L
cPAHs TEQ = 0.12 g/L
3.2.3 Points of Compliance
The POCs are the point or points where cleanup levels are attained. POCs for soil,
groundwater, and sediment are shown on Figure 3.1.
3.2.3.1 Soil Points of Compliance
Lora Lake Apartments Parcel
Soil direct contact. The POC for the soil cleanup level is based on the direct contact
exposure pathway. The MTCA standard POC for soil direct contact is throughout the
LL Apartments Parcel, from the ground surface to a depth of 15 feet bgs (WAC 173-
340-740(6)(d); Ecology 2007). However, Ecology recognizes that soil cleanup levels
for direct contact to a depth of 15 feet bgs will not typically be met in portions of sites
that use containment. In these cases, the cleanup action may be determined to comply
with cleanup standards provided the selected remedy is permanent to the maximum
extent practicable and is protective of human health. All soil with dioxins/furans
concentrations exceeding 13 pg/g TEQ within the POC must be contained or
excavated. The POC is the LL Apartments property boundary, and a zone of the
former Seattle City Light Property, as shown in Figure 3.1. This POC also establishes
the area that must be covered by a barrier to wildlife.
Protection of groundwater. The POC for soil to protect groundwater is throughout
the Site. Groundwater sampling has empirically demonstrated that groundwater
contamination is limited to areas where soil dioxins/furans TEQ exceedances are
greater than 100 times the cleanup level (1,000 pg/g TEQ). The soil POC for protecting
groundwater will be the limits of soil with dioxins/furans TEQ concentrations exceeding
about 10 times the cleanup level. This is the area where soil exceeds 100 pg/g TEQ,
the remediation level set above. All soil exceeding the 100 pg/g TEQ dioxins/furans
remediation level must be excavated and disposed of off-site at a properly permitted
facility.
Protection of wildlife. The LL Apartments Parcel qualifies for an exclusion from TEE
assessment because its future use is commercial and it has a barrier to wildlife
exposure. This exclusion requires an institutional control to ensure the excluded area
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is covered by barriers that will prevent wildlife from being exposed to the soil
contamination. We anticipate that the institutional control will apply to the LL
Apartments Parcel property boundary.
Lora Lake Parcel
The soil POC bounds the areas of soil in the LL Parcel where some soil dioxins/furans
TEQ concentrations exceed the TEE cleanup level of 5.2 pg/g TEQ. This POC is shown
on Figure 3.1. The POC for current sediment that will be converted to soil in the future by
implementation of the remedy is discussed below as sediment.
1982 Dredged Material Containment Area
The DMCA is an industrial area. Hence, industrial soil cleanup levels were used for
comparison to COC detected concentrations. The POC is the extent of the DMCA. An
institutional control is required when industrial cleanup levels are used (WAC 173-340-
440(4)(c)) to maintain the area covered by the institutional control in industrial use. An
environmental covenant will be placed on the area within the DMCA POC, requiring it be
kept in industrial use.
3.2.3.2 Groundwater Point of Compliance
The standard POC for groundwater under MTCA is "throughout the site from the
uppermost level of the saturated zone extending vertically to the lowest depth which could
potentially be affected by the site" (WAC 173-340-720(8)(b)). At the LL Apartments Site,
the standard POC for groundwater applies and cleanup levels will be met by the proposed
cleanup action. The groundwater POC is shown on Figure 3.1.
3.2.3.3 Lora Lake Sediment Point of Compliance
Modeling has indicated surface sediment COC concentrations in Lora Lake may cause
exceedances of surface water quality standards for dioxins/furans unless a remedial
action is performed. The POC for the existing sediment, the area exceeding sediment
cleanup standards within Lora Lake, is shown on Figure 3.1. This area must be
remediated in a manner to address surface sediment COC concentrations and prevent
leaching of COCs to surface water.
3.3 CONTAMINANT DISTRIBUTION
The following sections summarize the current extent of Site COCs in impacted media as
identified by the RI/FS, including soil, groundwater, and sediment. As previously
discussed, following remedy implementation, sediments at the LL Parcel will no longer
meet the regulatory definition of sediment, and, therefore, will be compared to soil cleanup
standards; however, the following sections describe the current contaminant distribution,
and discuss lake sediment separate from soil. Figure 3.2 summarizes the distribution of
the COCs in soil at the three areas of the Site compared to their cleanup levels. The
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values presented show the degree of cleanup level exceedance by the maximum
detected COC concentration in units of "times greater than the cleanup level."
This section also discusses establishment of a dioxins/furans remediation level for soil.
3.3.1 Soil
3.3.1.1 Lora Lake Apartments Parcel Contaminant Distribution
Soil contamination on the LL Apartments Parcel reflects the history of use of the Site.
Contamination is highest and deepest in the area of the concrete sump where barrelwashing
operations occurred (refer to Figure 2.4). During development of the land for
apartment construction, soil was pushed downslope to the east for grading; high
concentrations of COCs occur here. Exceedances of cleanup levels for COCs other than
dioxins/furans are associated with higher concentrations of dioxins/furans. Over much of
the rest of the LL Apartments Parcel, dioxins/furans contamination is shallow and
dioxins/furans concentrations are less than 10 times the cleanup level.
The distribution of dioxins/furans contaminant concentrations is such that most of the
mass of dioxins/furans is in the areas that exceed 10 times the dioxins/furans cleanup
level. Figure 3.3 shows the relationship between soil volume and dioxins/furans TEQ
concentrations. The figure shows that the soil volume with dioxins/furans TEQ less than
10 times the cleanup level (30,000 cubic yards) is approximately 1.6 times greater than
the soil with dioxins/furans TEQ greater than 10 times the cleanup level
(19,000 cubic yards).
Approximately 88 percent of the mass of dioxins/furans in the soil is in the areas where
dioxins/furans exceed 100 times the cleanup level. Approximately 96 percent of the mass
of dioxins/furans is in the areas where dioxins/furans exceed 10 times the cleanup level.
Approximately 4 percent of the mass of dioxins/furans is in areas where dioxins/furans
are less than 10 times the cleanup level.
3.3.1.2 Dioxins/Furans Remediation Level
A remediation level is a contaminant concentration greater than which a more aggressive
cleanup action will be taken. Remediation levels are greater than cleanup levels.
A remediation level of 100 pg/g TEQ (about 10 times the cleanup level) for dioxins/furans
has been selected at the LL Apartments Parcel. This level was determined by considering
the relationship between soil volume excavation and reduction in site-wide dioxins/furans
TEQ mass concentration shown on Figure 3.3. If the remediation level was set at less
than 100 pg/g TEQ, a disproportionate increase in excavation volume, and hence in cost,
is required to achieve a lower dioxins/furans TEQ concentration of soil left on-site (refer
to WAC 173-340-360(e) and discussion in Section 5.0).
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In the context of the Site, soil present on the LL Apartments Parcel with dioxins/furans
TEQ concentrations exceeding the remediation level will be excavated and sent to an offsite
disposal facility. Soil with dioxins/furans TEQ concentrations less than the
remediation level will be contained on-site to prevent exposure. Institutional controls to
provide for maintenance of the containment will be included in an environmental
covenant.
3.3.1.3 Lora Lake Parcel
Only dioxins/furans and lead concentrations in soil on the LL Parcel exceed their cleanup
levels. The other COC concentrations are less than their cleanup levels. A technical
memorandum describing dioxins/furans TEQ concentrations in LL Parcel soil was
submitted to Ecology in August 2013 (Floyd|Snider 2013). Refer to RI/FS Figure 4.2 for
maximum lead concentrations measured in soil at the LL Parcel.
Lead exceeded its cleanup level of 50 mg/kg in 2 of the 19 soil samples collected in which
lead was measured, at concentrations of 58 and 64 mg/kg. These concentrations were in
the surface soil.
Dioxins/furans exceeded the cleanup level of 5.2 pg/g TEQ in 10 of the 29 soil samples
collected. It exceeded twice the cleanup level in 5 of 10 exceeding soil samples.
Whether the dioxins/furans concentrations detected in the soil sampled from the LL Parcel
are related to historical industrial operations or to general urban background
concentrations cannot be determined.
3.3.1.4 1982 Dredged Material Containment Area
Soil COC concentrations at the DMCA were all less than their cleanup levels, which are
based on industrial land use. Soil within the DMCA was dredged from Lora Lake in 1982.
3.3.2 Groundwater
The only well on-site that had an exceedance of the dioxins/furans cleanup level is located
in the concrete sump area (Well MW-1) where barrel-washing activities occurred and
dioxins/furans TEQ soil concentrations are highest. The highest dioxins/furans TEQ
groundwater concentration was approximately 5.7 times its cleanup level. Arsenic was
almost 3 times its cleanup level at this location (refer to Figure 3.2).
Dioxins/furans TEQ concentrations in groundwater attenuate rapidly due to their strong
tendency to sorb to soil. The wells downgradient of the historical industrial operations
area do not have dioxins/furans TEQ concentrations exceeding their cleanup level.
Arsenic and PCP exceeded their cleanup levels in one well on the eastern boundary of
the LL Apartments Parcel. This is downgradient of the concrete sump area where barrelwashing
activities occurred.
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3.3.3 Lora Lake Sediment
Bioassay results found that surface sediment quality was protective of benthic organisms.
To evaluate the extent of contamination for the existing lake sediments and assess
remedial alternatives, COC surface sediment concentrations were compared to the
sediment cleanup levels as presented in the RI/FS. Dioxins/furans TEQ concentrations
ranged from 7.55 pg/g TEQ to 217 pg/g TEQ. While dioxins/furans strongly sorb to
soil/sediment and have very low solubility in water, the National Recommended Water
Quality Standard for surface water to protect human health is very low (0.005 pg/L). The
standard is low because dioxins/furans are highly bioaccumulative in fish. All other COCs
were not detected at concentrations greater than the respective Cleanup Screening
Levels as presented in the RI/FS. The extent of sediment contamination in Lora Lake was
identified in the RI/FS as the entire footprint of the lake.
Additionally, a numerical cap modeling evaluation was conducted as part of the RI/FS for
all surface sediment COCs (i.e., arsenic, dioxins/furans, PCP, and cPAHs) to (1) further
assess the potential for sediment COCs in Lora Lake to leach from sediments to surface
water at concentrations greater than those permitted by applicable surface water
standards, and (2) to assess remedial alternatives. The Lora Lake numerical cap
modeling evaluation and the resulting remedial alternative is discussed in Section 5.2.
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4.0 Cleanup Areas
The LL Apartments Parcel and LL Parcel have been divided into Cleanup Areas for
application of remedial technologies. Remedial alternatives were developed and
evaluated for each cleanup area in the RI/FS (refer to Section 5.0). Descriptions of the
Cleanup Areas for the LL Apartments Parcel and LL Parcel are presented below.
The DMCA did not require division into Cleanup Areas.
4.1 LORA LAKE APARTMENTS PARCEL CLEANUP AREAS
Because the application of remedial technologies to a given area of the LL Apartments
Parcel is based primarily on the nature and extent of the contamination, Cleanup Areas
have been determined so that a single remedial component may be conducted in areas
with similar nature and extent of contamination conditions.
Based on nature and extent of contamination, the LL Apartments Parcel has been divided
into three Cleanup Areas (illustrated on Figure 4.1): Cleanup Areas A, B, and C. The
extent of each Cleanup Area is defined by soil cleanup levels based on protection of
human health by direct contact (assuming unrestricted land use) and the soil remediation
level for dioxins/furans (refer to Section 3.3.1.2). Cleanup Areas A, B, and C are described
below.
4.1.1 Cleanup Area A
Cleanup Area A designates two separate locations at the LL Apartments Parcel where
the maximum detected dioxins/furans TEQ concentration in soil at any depth is greater
than 1,000 pg/g TEQ. Concentrations of dioxins/furans identified during the RI in Cleanup
Area A range from 1,000 to 21,165 pg/g TEQ dioxins/furans. Additional COCs present,
and their associated maximum concentrations, include: cPAHs (880 g/kg), PCP
(15,000 g/kg), total petroleum hydrocarbons (1,900 mg/kg, 8,900 mg/kg, and
17,000 mg/kg for gasoline range, diesel range, and heavy oil range, respectively) and
lead (2,880 mg/kg). Cleanup Area A is presented on Figure 4.1. The total acreage of
Cleanup Area A is approximately 0.7 acre, comprising two different locations:
The Central Source Area, which is the location of the historical barrel-washing
drum cleanout pond.
The Eastern Source Area along the eastern property line in the vicinity of
Monitoring Wells MW-4 and MW-5.
The soil in Cleanup Area A is contaminated from the ground surface to a maximum depth
of approximately 15 to 20 feet bgs from past releases associated with historical barrelwashing
operations, auto-wrecking operations, and soil relocation during apartment
construction and site grading. Cleanup Area A also encompasses the area with currently
contaminated groundwater. Groundwater in Area A is expected be in compliance with
cleanup levels within 5 years of removing the source of contaminants to groundwater.
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Maximum concentrations of COCs in groundwater samples collected between 2010 and
2011 include: arsenic (14.2 micrograms per liter [g/L]), cPAHs (0.028 g/L), PCP
(1.4 g/L), and dioxins/furans (38.3 g/L).
4.1.2 Cleanup Area B
Cleanup Area B includes all locations within the LL Apartments Parcel where the
maximum detected dioxins/furans TEQ concentration in soil at any depth is between
100 pg/g TEQ and 1,000 pg/g TEQ. Cleanup Area B is adjacent to the source areas within
Cleanup Area A. Substantial site regrading activities during construction of the apartment
complex in the mid-1980s are likely responsible for the widespread presence of
dioxins/furans across the shallow surface soil at the LL Apartments Parcel. Based on
existing data, Cleanup Areas A and B (in combination) are believed to contain all soil on
the LL Apartments Parcel where dioxins/furans TEQ concentrations are greater than
100 pg/g TEQ. Cleanup Area B is presented on Figure 4.1. The total acreage of Cleanup
Area B is approximately 2.2 acres and consists of the following locations:
The west-central portion of the LL Apartments Parcel. This location
encompasses dioxins/furans contamination observed in surface soils
(0 to 0.5 feet bgs) from Boring PSB-04 at a concentration of 194 pg/g TEQ.
The Western Source Area near the LL Apartments Parcel property boundary
with the former Seattle City Light Property. This area encompasses
dioxins/furans contamination observed in soil from 0 to 2 feet bgs at
concentrations ranging from 56 pg/g TEQ to 702 pg/g TEQ. This area also
contains cPAH contamination observed from 2 to 4 feet bgs at a maximum
concentration of 160 g/kg.
A zone between and north of the Central Source Area and the Eastern Source
Area. This area encompasses dioxins/furans contamination observed in soil
from 0 to 2 feet bgs at concentrations ranging from 132 to 187 pg/g TEQ.
A zone along the southeastern property line, primarily east of the Eastern
Source Area. Much of this area is outside the property fence, along Des Moines
Memorial Drive at the foot of the topographic slope. This area encompasses
dioxins/furans contamination observed in surface soils (0 to 0.5 feet bgs) with
concentrations ranging from 107 to 209 pg/g TEQ.
4.1.3 Cleanup Area C
Cleanup Area C includes all locations within the LL Apartments Parcel property boundary
where the maximum detected dioxins/furans TEQ concentration at any depth is between
13 and 100 pg/g TEQ. In the limited areas where data indicate dioxins/furans TEQ
concentrations are present outside the property boundary, the dioxins/furans
concentrations are within the range of typical urban background (refer to Appendix M and
Figure 4.9 of the RI/FS for more information) and cannot be attributed to the industrial
operations on the LL Apartments Parcel. Cleanup Area C is presented on Figure 4.1. The
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total acreage of Cleanup Area C is approximately 3.3 acres and consists of the following
locations:
In the western portion of the property dioxins/furans contamination was
detected in soil between 0 and 2 feet bgs, at concentrations ranging from
11.5 to 33.8 pg/g TEQ.
In the northeast corner of the property exceedances of the cleanup level are
present in shallow soil (0 to 2 feet bgs) at concentrations ranging from 16.6 to
26.2 pg/g TEQ.
The central portion of the property between Cleanup Areas A and B, directly
south of the Central and Eastern Source Areas, at concentrations ranging from
11.6 to 57 pg/g TEQ detected in surface soil between 0 and 0.5 feet bgs.
4.2 LORA LAKE PARCEL CLEANUP AREAS
This section identifies Cleanup Areas for the LL Parcel. The application of technologies
to the LL Parcel is based primarily on the ecological characteristics of the cleanup area
(i.e., soil or sediment), the nature and extent of the contamination, its physical location,
and institutional considerations. The existing LL Parcel includes both soil- and sedimentcontaminated
zones, and zone-specific remedies. The LL Parcel has been divided into
two Cleanup Areas, illustrated on Figure 4.2: the LL Parcel Shallow Soil Cleanup Area
and the LL Parcel Sediment Cleanup Area. The extents of the Cleanup Areas are defined
by soil cleanup levels based on protection of terrestrial ecological receptors for the LL
Parcel Shallow Soil Cleanup Area, and protection of surface water via sediment leaching
for the LL Parcel Sediment Cleanup Area (refer to Section 3.0). The LL Parcel Shallow
Soil Cleanup Area and the LL Parcel Sediment Cleanup Area are described below.
4.2.1 Shallow Soil Cleanup Area
Shallow soil at the LL Parcel is contaminated with dioxins/furans at concentrations greater
than the natural background-based cleanup level of 5.2 pg/g TEQ for protection of
ecological receptors. Soil contamination exists along the western property boundary at
depths ranging from 0 to 5 feet bgs. The Cleanup Area extent identified in the RI/FS has
been refined based on additional data collected in February 2013 (Floyd|Snider 2013).
Figure 4.2 presents the revised LL Parcel Shallow Soil Cleanup Area. The additional data
confirmed dioxins/furans concentrations in shallow soils do not extend past the STIA
security fencing to the north and do not extend as far to the east as was conservatively
estimated in the RI/FS. Soil concentrations from the additional 2013 sample locations
ranged from 0.177 pg/g TEQ dioxins/furans to 6.12 pg/g TEQ dioxins/furans. The updated
Cleanup Area is composed of two areas, one approximately 25 feet by 90 feet, and the
other approximately 25 to 65 feet wide, and approximately 155 feet long. Both areas
extend to the paved sidewalk along Des Moines Memorial Drive, and together are
approximately 0.2 acre.
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The LL Parcel Shallow Soil Cleanup Area is within area covered by the NRMP. Its current
and future use will be as a habitat mitigation area.
4.2.2 Sediment Cleanup Area
The LL Parcel Sediment Cleanup Area encompasses sediments within the lake and
extending to the lake shoreline. The lake surface is approximately 3 acres. All Lora Lake
sediments are encompassed by the LL Parcel Sediment Cleanup Area, which is shown
on Figure 4.2.As described in Appendix P of the RI/FS and below in Section 5.2, the
results of the numerical modeling evaluation indicated that the necessary sand cap
thickness to effectively attenuate and isolate the surface sediment COC concentrations
of 18-inches with a 0.06 percent organic carbon content is driven by arsenic and
dioxins/furans. Dioxins/furans are present at concentrations ranging from 7.55 pg/g TEQ
to 217 pg/g TEQ in surface sediments. Arsenic is present at concentrations ranging from
7 mg/kg to 70 mg/kg in surface sediments.
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5.0 Selected Remedy
The RI/FS evaluated five cleanup alternatives for the LL Apartments Parcel and four
cleanup alternatives for the LL Parcel.
The DMCA is within the City of SeaTac's Aviation Operations zone. The area of the DMCA
qualifies as an industrial area pursuant to WAC 173-340-745(1). Soil COCs do not exceed
industrial direct contact cleanup levels within the DMCA and are not impacting
groundwater. The DMCA qualifies for an exclusion from a TEE because future use will
include an engineered surface that is a barrier to wildlife. An institutional control will be
placed on the DMCA to keep it in industrial use and maintain a barrier to wildlife.
The cleanup remedies for the Site were selected in accordance with and comply with the
requirements of WAC 173-340-360 for selection of cleanup actions.
5.1 LORA LAKE APARTMENTS PARCEL
The cleanup alternatives considered in the RI/FS for the LL Apartments Parcel are
summarized in Table 5.1. The alternatives use varying degrees of excavation and off-site
disposal of contaminated soil and containment of remaining contaminated soil.
Groundwater cleanup alternatives range from monitoring and management to source
removal. All but Alternative 5 require environmental covenants. All alternatives include
storm drain system improvements to prevent entry of contaminated groundwater or soil,
which are described in Section 6.1.3. Conceptual costs for LL Apartments Parcel
alternatives range from $4.7 million to $9.2 million.
Ecology's selected remedy for the LL Apartments Parcel is Alternative 3. Alternative 3
provides for excavation and off-site disposal of soil containing dioxins/furans
concentrations greater than 100 pg/g TEQ. Soil with concentrations less than 100 pg/g
TEQ will be capped with a barrier to wildlife. A barrier to wildlife will be a sufficient barrier
to unintentional human intrusion, as required if the Port opts to contain soil with
dioxins/furans TEQ concentrations on the LL Apartments Parcel.
The Port has indicated they may prefer to consolidate soil with dioxins/furans TEQ
concentrations equal to or less than 100 pg/g TEQ within the DMCA to facilitate
development of the LL Apartments Parcel. This is Alternative 4. The Port may opt to
implement LL Apartments Parcel Alternative 4 if it so chooses. Consolidating soil with
dioxins/furans TEQ concentrations equal to or less than 100 pg/g TEQ at the DMCA better
meets Ecology's expectation to consolidate contaminated soil to the maximum extent
practicable (WAC 173-340-370(5)); however, the increased cost offsets the
environmental benefit.
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The RI/FS provides a detailed discussion of the remedy selection process (refer to
Sections 12.0 and 13.0). The primary reasons for selecting Alternative 3 are as follows:
Alternatives 1 and 2 leave substantial amounts of contamination on-site to be
managed with institutional controls. Institutional controls do not have the same
long-term effectiveness as other cleanup actions, such as excavation and
removal. Moreover, the cost of excavation and removal of additional soil with
dioxins/furans TEQ concentrations greater than the 100 pg/g TEQ
concentration is proportionate to the incremental environmental benefit gained
from removing this high-concentration material from the Site. Because
Alternatives 1 and 2 leave soil with higher contaminant concentrations on-site
more than the other alternatives, there is greater uncertainty as to whether the
source removal will be protective of groundwater throughout the Site.
Alternatives 1 and 2 also would result in a higher risk to human health if a cap
over the higher concentration soil were to be penetrated.
Alternative 4 requires excavation and on-site consolidation at the DMCA of an
additional 30,000 cubic yards of soil compared to Alternative 3, with an
accompanying import of clean backfill and transport of the excavated soil to the
nearby DMCA. The Port has indicated to Ecology that they may prefer this more
expensive cleanup alternative for business reasons. The Port may implement
Alternative 4 instead of Alternative 3 at its option.
Alternative 5 requires excavation and off-site disposal of an additional
30,000 cubic yards of soil compared to Alternative 3, also with accompanying
import of clean backfill and transport of the excavated soil to a distant properly
permitted facility. The additional soil has dioxins/furans concentrations between
11 and 100 pg/g TEQ. This concentration range is within the range that may be
encountered in the urban Seattle area (Ecology 2011). Capping and
institutional controls are more suitable for addressing this high volume of soil
with relatively low dioxins/furans TEQ concentrations.
Alternative 3 has been chosen as the action that best balances the protection
of human health and the environment with the cost of cleanup. Removing soil
with dioxins/furans concentrations exceeding 100 pg/g TEQ is expected to
remove the source of groundwater contamination. This will be verified by
groundwater monitoring. The primary considerations in choosing Alternative 3
include the following:
o Figure 5.1 shows the alternative cost versus the percent of dioxins/furans
mass in the soil removed. The figure shows that soil excavation is cost
effective in removing dioxins/furans mass at concentrations greater than
100 pg/g TEQ. When the soil dioxins/furans concentrations become less
than 100 pg/g TEQ the amount of soil to be removed, and hence the cost,
to further reduce soil dioxins/furans TEQ concentrations by excavation and
off-site disposal increases rapidly as the mass of dioxins/furans in a cubic
yard of soil is much less at concentrations less than 100 pg/g TEQ than
concentrations greater than 100 pg/g TEQ. The regulation requires that
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cleanups be permanent to the maximum extent practicable and that where
incremental costs substantially exceed incremental benefits, a lower cost
alternative will be chosen (WAC 173-340-360(2)(b)(i) and (3)(e)(i))
Figure 5.1 shows the increased cost of excavation and off-site disposal rises
disproportionally to the increased environmental benefit of excavation of
large volumes of soil with lower concentrations of dioxins/furans. Capping
of soil with dioxins/furans TEQ concentrations less than 100 pg/g TEQ will
achieve protection human health and the environment more cost effectively
than excavation.
o The soil to be capped on the LL Apartments Parcel (or consolidated within
the DMCA and capped, if the Port chooses that option) has dioxins/furans
TEQ concentrations within the range found within urban areas of Seattle
(refer to Figure 5.2). Alternative 3 recognizes Ecology's expectation of the
need to use engineering controls, such as containment, for sites or portions
of sites that contain large volumes of materials with relatively low levels of
hazardous substances where treatment is impracticable
(WAC 173-340-370(3)).
5.2 LORA LAKE PARCEL
The cleanup alternatives considered in the RI/FS for the LL Parcel are summarized in
Table 5.2. Alternatives for Lora Lake include (1) controlling sediment and fish movement
from Lora Lake to Miller Creek, (2) thin capping, (3) capping then filling the lake to restore
the wetland that existed prior to peat mining, (4) and dredging and off-site disposal of
contaminated sediment. Alternatives for the LL Parcel Shallow Soil Cleanup Area include
controlling risk with institutional controls, capping, and excavation and off-site disposal.
Alternatives 1, 2, and 3 include environmental covenants to maintain restoration and keep
the land in its current use. Conceptual costs for LL Parcel alternatives range from
$0.4 million to $7.3 million.
Ecology's selected remedy for the LL Parcel is Alternative 3.
A numerical cap modeling evaluation was conducted as part of the RI/FS for all surface
sediment COCs (i.e., arsenic, dioxins/furans, PCP, and cPAHs) to (1) further assess the
potential for sediment COCs in Lora Lake to leach from sediments to surface water at
concentrations greater than those permitted by surface water Applicable or Relevant and
Appropriate Requirement, and (2) to assess remedial alternatives. The results of the
numerical modeling evaluation indicated that capping is a viable technology and remedial
alternative in terms of the effectiveness of isolating contaminants (Appendix P of the
RI/FS). The results of this evaluation indicate that a sand cap thickness of 6 inches with
a 0.06 percent organic carbon content would effectively isolate the surface sediment
concentrations of lead, cPAHs, and PCP and attenuate their concentrations in pore water
to protect surface water. The results also indicated that a thicker sand cap of 18 inches
and 0.06 percent organic carbon content would be needed to effectively attenuate and
isolate the surface sediment concentrations of arsenic and dioxins/furans. Therefore,
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based on the modeling results, the placement of an cap with the isolation capacity of an
18-inch sand cap with a minimum 0.06 percent organic carbon content on top of the Lora
Lake sediments would be protective of the surface water human health pathway via fish
and water consumption for all COCs.
Alternative 3 for the lake portion of the parcel provides for restoring Lora Lake to a
palustrine scrub-shrub wetland system (Figure 6.1). This alternative results in the
conversion of the existing open water and benthic sediment conditions of the lake to a
palustrine scrub-shrub wetland with wetland soils. Contaminated lake sediment will be
contained in place using a sand cap that will be designed to immobilize COCs in the
sediment. This will prevent leaching of COCs to surface water. The wetland will be
designed so that it does not adversely impact the functioning of the Port's mitigation areas
covered by the NRMP. This includes not adversely impacting flood frequencies in Miller
Creek. The wetland design and construction will also comply with all applicable permits
and resource agency requirements.
Alternative 3 for the soil portion of the parcel provides for excavation of contaminated soil
and restoration and replanting of the excavated area in accordance with the NRMP.
The RI/FS provides a detailed discussion of the remedy selection process (refer to
Sections 12.0 and 13.0). The primary reasons for selecting Alternative 3 for the lake and
soil portions of the parcel are as follows:
With regard to the lake:
Alternative 1 will not prevent interchange of water between Lora Lake and Miller
Creek; hence, it is not sufficiently protective if dioxins/furans leach from
sediment to the lake water.
Alternative 2 proposes a single layer thin (1.5 foot) sand cap. A thin cap with
sufficient carbon content would be effective at immobilizing the COCs in the
sediment. However, a thin cap is more easily disturbed; therefore, its long-term
effectiveness is less certain than a cap that is used in combination with a thick
fill layer and converts the lake to a palustrine scrub-shrub wetland. In addition,
a thin cap would further shallow this already shallow lake. Lora Lake is currently
a source of low-oxygen, high-temperature water to Miller Creek in the summer.
A shallow cap would exacerbate this condition. Ecology expects that cleanup
actions conducted under this chapter will not result in a substantially greater
overall threat to human health and the environment than other alternatives
(WAC 173-340-370(8)). Alternative 2 could result in a greater environmental
damage to Miller Creek than the environmental benefit achieved.
Alternative 4 presents short-term risks of spreading contamination on the land
or having it enter the water during dredging of the lake. In addition, it is
substantially more expensive than Alternative 3 and would not achieve
substantially greater environmental protection than immobilizing the COCs by
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installing a sand cap over the contaminated sediments, covering the cap with
a fill layer and wetland soil, and restoring the lake to wetland conditions.
Alternative 3 will provide a sand cap designed to immobilize the current
sediment COCs in place. This will prevent leaching of COCs to surface water.
Ecology recognizes immobilization as having good long-term effectiveness
(WAC 173-340-360(3)(f)(iv)). Alternative 3 includes placement of a fill layer and
wetland soil over the isolated sediment contamination, restoring the lake to
wetland conditions. This has the added benefit of converting the open-water
lake to an upland wetland, thereby eliminating a source of low-oxygen, hightemperature
water to Miller Creek in the summer.3
With regard to the soil at the LL Parcel, the soil is located within a special
purpose wetland landscape and habitat mitigation area. The plant communities
were planted in 2005 and 2006. Necessary infill planting to keep density
numbers high has been completed intermittently since then, with the last
planting effort completed in 2010. Currently, the area of concern is mature
enough to meet its desired goals. The buffer has grown to provide a dense
break between the nearby road and the adjacent wetland and lake. Grading
and floodplain connection have been completed. The wetland vegetation has
undergone minor corrective actions that have allowed the area to reach cover
and density performance levels that either meet, or are rapidly approaching,
the final performance standards for the area. The Port continues the
management of the plant coverage and diversity that exists within the potential
extent of soil excavation to support the targeted ecological functions.
Excavation and containment at the DMCA or off-site disposal of soil from the
LL Parcel Shallow Soil Cleanup Area will result in compliance with the
applicable Lora Lake Parcel soil cleanup level of 5.2 pg/g dioxins/furans. This
cleanup level is protective of terrestrial exposure at the Lora Lake Parcel.
Excavation will destroy established high-value mitigation plantings. Th e
excavation design will reduce this impact by reducing the extent of excavation
as much as possible while excavating sufficient soil to comply with the cleanup
standards and restoring the excavated portion of the Mitigation Area to the
condition specified in the NRMP. This accords with provisions of the Restrictive
3 As part of the Port's mitigation for Master Plan Update improvement impacts, a portion of Miller Creek was relocated.
The relocated section of Miller Creek was designed to provide a salmonid spawning habitat; however, the relocation
resulted in areas of standing water and limited flow velocity. The Port implemented corrective actions to limit areas of
standing water and improve stream flow. In addition to standing water and limited flow, assessments of the original
relocation reach identified stream temperatures greater than, and dissolved oxygen levels less than, the water quality
standards. These deficiencies during the summer months were partially attributed to upstream influences, including
discharges from Lora Lake. To further improve water quality in Miller Creek, the resource agencies overseeing the
mitigation area have recommended that surface flows from Lora Lake be prevented from entering Miller Creek during
late spring, summer, and early fall.
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Covenant on the property that any activity in the Mitigation Area shall use
methods that minimize damage to the Mitigation Area (Port of Seattle 2003).
The chosen remedy of excavating selected areas of the LL Parcel Shallow Soil
Cleanup Area will bring the average dioxins/furans TEQ concentrations
remaining on-site to less than the cleanup level while minimizing destruction of
established plantings. Following excavation, the area will be backfilled and
replanted, and managed in accordance with the requirements and
management goals of the NRMP.
5.3 1982 DREDGED MATERIAL CONTAINMENT AREA
As noted above, Ecology's selected remedy for the DMCA is placing institutional controls
on the area. Institutional controls are required when soil cleanup levels are based on
industrial land use. As the future land use will have a barrier to wildlife, the DMCA also
qualifies from an exclusion from a TEE. This exclusion also requires an institutional
control.
The Port plans to make land use improvements at the DMCA to allow for its future use as
a temporary construction laydown or as equipment storage. The improvements will
consist of surface improvements (e.g., placement of a compacted gravel or engineered
surface) that will prevent plant and wildlife exposure pathways. Soil from the Lora Lake
Apartments Parcel and the LL Parcel Shallow Soil Cleanup Area with dioxins/furans
concentrations less than 100 pg/g TEQ may be consolidated at the DMCA (Figure 6.1).
If this occurs, the consolidation area and surface improvements will be designed
considering potential erosion from flood events, and constructed accordingly.
Construction requirements will include Temporary Erosion and Sedimentation Control
Best Management Practices (BMPs), as is standard practice at construction sites.
According to current maps, approximately 1,000 square feet (0.7 percent) of the DMCA
along its southern boundary may lie within the 100-year floodplain. Prior to consolidation,
the boundary of the 100-year floodplain will be surveyed, and no material will be
consolidated in this area.
Material consolidation at the DMCA will raise the elevation of the area by approximately
6 to 8 feet. Design of the DMCA consolidation area and engineered surface will consider
this, and will be constructed to prevent contaminant migration, including migration during
flood events. Filled areas will be constructed, and protected from erosion with slope
stabilization construction techniques.
The method for erosion protection of the wildlife barrier will be determined in design, and
may consist of a geotextile (a woven plastic fabric) or similar reinforcement layers,
crushed rock, or riprap, or other durable materials. The DMCA will be inspected regularly
to assess its integrity, and any necessary repairs made. Repairs also will be made
whenever damage is observed. The inspection schedule will depend upon the nature of
the final surface of the DMCA.
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Institutional controls will be placed on the DMCA by recording an environmental covenant
to require that it remains an industrial use area and to ensure a barrier to wildlife is
maintained in the future.
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6.0 Selected Remedy Implementation
6.1 LORA LAKE APARTMENTS PARCEL REMEDY IMPLEMENTATION
6.1.1 Soil
The Port will excavate all contaminated soil with dioxins/furans TEQ concentrations
greater than 100 pg/g TEQ (about 19,000 cubic yards) for off-site disposal at a properly
permitted facility. The remaining contaminated soil, containing dioxins/furans TEQ
concentrations between 13 pg/g TEQ and 100 pg/g TEQ (about 30,000 cubic yards) will
either be contained beneath a barrier to wildlife within the LL Apartments Parcel or, at the
Port's option, transported to the DMCA and contained beneath an engineered surface
that is a barrier to wildlife.
Excavations will be backfilled to final grade with imported soil or with soil from within the
LL Apartments Parcel boundary with dioxins/furans TEQ concentrations less than
100 pg/g TEQ. Imported backfill will be sourced from a facility or location in which an
assessment has been conducted to confirm that there are no impacts to fill material based
on historical operations. The contractor selected to complete the work will be required to
provide confirmation that backfill meets the requirements outlined in the project
specifications. This will include sourcing from an area with no industrial history and testing
the material to ensure the material meets the requirements of the project specifications.
A barrier to wildlife will be established within 4 years of the completion of excavation and
backfilling. This allows the Port time to identify the commercial use of the property and
integrate the barrier to wildlife with property development. The barrier design requires
Ecology approval. Excavation will be considered complete when excavation has extended
to the pre-determined and approved survey coordinates based on the results of
compliance monitoring conducted prior to excavation (refer to Section 6.5). Backfilling will
be considered complete when excavations have been backfilled to design grade as
specified in the project plans and specifications.
After excavation and backfilling have been completed stormwater and erosion control
measures will be implemented and maintained. The measures will control dust generation
as well.
Any existing groundwater monitoring wells within the limits of excavations and deeper
than anticipated excavation depths must be abandoned in accordance with regulations
prior to the start of excavation.
6.1.2 Groundwater
The excavation of Cleanup Area A is expected to remove the contaminant mass above,
and in contact with, groundwater in Cleanup Area A, which may contribute to the elevated
dioxins/furans concentrations in groundwater at Monitoring Well MW-1. Following
removal of this saturated soil source, compliance groundwater sampling will be conducted
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until groundwater concentrations are in compliance with cleanup levels. It is anticipated
that groundwater will be in compliance with cleanup levels within 5 years from completion
of excavation and backfilling. Until groundwater concentrations are less than cleanup
levels, institutional controls will be required to prevent groundwater withdrawal.
Groundwater encountered during excavation and removed from the subsurface for
excavation dewatering will be either treated as needed and discharged to the sanitary
sewer under a discharge permit, or collected for off-site disposal at a properly permitted
facility. Dewatering methods will be determined by the Contractor and approved by the
Port prior to implementation.
The final monitoring well network will be determined in the Compliance Monitoring Plan
(refer to Section 6.5). New wells may be required at locations where wells were
abandoned as part of cleanup construction.
6.1.3 Stormwater Conveyance System Improvements
A City of Burien storm drain currently traverses the LL Apartments Parcel and conveys
stormwater from upstream across the property to Lora Lake (the Main Line). The City of
Burien is planning a stormwater project that would entail constructing a new stormwater
pipe that would redirect the upstream stormwater down 8th Avenue South to a new
stormwater facility. The stormwater facility would be located south of the LL Apartments
Parcel and would provide infiltration treatment of the water quality design storm volume
for current land use consistent with Ecology's Stormwater Management Manual for
Western Washington (Ecology 2012).
If the City of Burien implements the project to redirect the upstream water down 8th
Avenue South to a new stormwater facility prior to Site remedy construction, the existing
Main Line will be abandoned in place or removed entirely from the LL Apartments Parcel
during the site excavation.
If the City of Burien redirects the upstream stormwater down 8th Avenue South following
Site remedy construction, the main line will be temporarily diverted around the Site during
construction to discharge temporarily to Miller Creek or another area of the Port-managed
mitigation area wetlands downgradient of construction until the City of Burien work is
complete. If the City of Burien work is not conducted, following Site remedy construction
the Main Line will convey the upstream stormwater to the rehabilitated wetland on the LL
Parcel and be infiltrated (refer to Section 6.2.2 for discussion of wetland design). If the
Main Line continues to traverse the Site, the utility would be lined in a manner that
prohibits groundwater infiltration and penetration of soils into the pipe.
There is a small segment of Des Moines Memorial Drive from which runoff may continue
to drain to the Lora Lake Parcel following construction of this project, or may be redirected
as part of City utility improvements. This will be determined during the design process for
this work, and will comply with all applicable regulations.
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6.1.4 Environmental Covenants
Environmental covenants will be placed on the LL Apartments Parcel to implement
institutional controls. The covenants will require institutional controls to maintain the
barrier to wildlife, to prevent groundwater withdrawal during the restoration time frame it
will take for the groundwater to achieve compliance after cleanup construction is complete
(estimated to be 5 years), and to require that the area remains in commercial use.
The environmental covenant shall describe the nature and extent of contamination
remaining on-site after completion of cleanup construction.
Two draft environmental covenants will be submitted to Ecology for review and approval
with the draft As-built Reports for the work (Refer to Section 6.6.4). One covenant will be
for maintenance of long-term institutional controls for the barrier to wildlife and to keep
the area in commercial use. The other will prevent groundwater withdrawal. It is
anticipated that this covenant will be removed once compliance monitoring indicates
groundwater meets cleanup standards.
Separate environmental covenants may be needed for the former Seattle City Light
Property (now owned by the Port) and a small area east of the Lora Lake Apartments
Parcel property boundary within the City of Burien right-of-way. The need for
environmental covenants for these areas will be determined after compliance monitoring
data have been collected and the concentrations remaining in these areas are known.
6.2 LORA LAKE PARCEL REMEDY IMPLEMENTATION
6.2.1 Shallow Soil Cleanup Area
The areas surrounding LL-SB6, LL-SB5, LL-SB5B, and LL-SB2 have dioxins/furans TEQ
concentrations exceeding the natural background concentration of 5.2 pg/g TEQ. These
areas will be excavated, backfilled with clean soil, and replanted. Excavated material will
be consolidated at the Dredged Material Containment Area. It may also be sent off-site
for disposal at a licensed disposal facility if that is more efficient for construction
scheduling.
The areas to be excavated are shown on Figure 4.2. Excavations will extend to the
sidewalk. Excavation of these areas will bring the average dioxins/furans TEQ
concentration to levels less than the required standard of 5.2 pg/g TEQ in the LL Parcel
Shallow Soil Cleanup Area. The average concentration is the value that is compared to
the required standard in order to demonstrate remedy compliance with cleanup
standards.
Sidewall samples will be collected from the west side of each excavation to assess
dioxins/furans concentrations beneath the City of SeaTac's sidewalk. An environmental
covenant will be placed on the area beneath the sidewalk, if necessary, depending upon
sampling results.
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One of the areas to be excavated, defined by boring LL-SB5 and LL-SB-5B, will be
excavated to a depth of 6 feet, as prior sampling did not vertically bound contamination
in this area. A soil sample will be collected from the bottom of the excavation. If the
dioxins/furans concentrations exceed 5.2 pg/g TEQ, a conditional POC will be established
at a depth of 6 feet. An environmental covenant will be established that regulates any
disturbance of deeper soil (refer to WAC 173-340-7490(4)(a)).
6.2.2 Sediment Cleanup Area (Future Wetland)
Lora Lake sediments will be isolated through capping and open-water filling of Lora Lake
to rehabilitate the area to wetland conditions. A clean sand cap with a minimum thickness
of 18 inches and a minimum organic carbon content of 0.1 percent will be placed in Lora
Lake. The sand cap will be placed to extend a minimum of 18 inches beyond the existing
lake footprint and current extent of contaminated sediment to provide containment at the
contaminated sediment margin. This specification provides a margin of safety over the
18-inch thickness with 0.06 percent organic carbon content sand cap found to be
sufficient by the Reible and Lampert computer model (Floyd|Snider 2015a, Appendix P).
This will eliminate the potential for aquatic exposure or transport of COC-contaminated
sediments. The sand cap will provide a physical and chemical barrier between the
contaminated sediments and water flowing into Miller Creek, addressing the human
exposure pathways.
The Engineering Design Report will include acceptance criteria for the fill material to
ensure it is uncontaminated, contains adequate organic carbon to immobilize COCs
(particularly arsenic and dioxins/furans), and meets any other specifications developed
during engineering design. Carbon amendments will be added if necessary. An
appropriate sampling and analysis plan will be developed when a potential fill source is
identified.
The capping of lake sediments and filling of Lora Lake will consist of placing sand in the
lake to an elevation that converts all of the open-water area to a palustrine scrub-shrub
wetland system. The lake will be filled over its entire footprint to depths between
approximately 2 and 13 feet, based on existing bathymetry.
Top soil suitable for the establishment of wetland plantings will be placed over the sand
fill material. Wetland design will include consideration of the potential for contaminant
migration by gas ebullition and bioturbation. The design will also maintain the Miller Creek
channel stability and will minimize erosion potential, as well as requiring placement of
high conductivity fill material (relative to the adjacent wetland soils) to maintain the current
upward groundwater flow path beneath Lora Lake.
The rehabilitated wetland will be capable of supporting emergent and woody vegetation
and will create habitat that is consistent with the goals of the NRMP. This wetland
rehabilitation is considered a preferred form of compensatory mitigation for ecological
impacts (Ecology et al. 2006) and, of all the remedial alternatives evaluated, will provide
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the maximum ecological benefit to the Miller Creek Basin (as described in detail in RI/FS
Section 20.0).
6.2.3 Environmental Covenants
An environmental covenant will be placed on the LL Parcel Sediment Cleanup Area. It
will require the rehabilitated wetland to continue to be managed in accordance with
recorded restrictive covenants already in place as part of the NRMP. This will ensure that
Ecology must agree to removing or changing these restrictive covenants with regard to
this area.
The environmental covenant will describe the nature and extent of contamination
remaining on-site after completion of cleanup construction.
A draft environmental covenant for the LL Parcel Sediment Cleanup Area will be
submitted to Ecology for consideration with the As-built Reports for the LL Parcel work
(refer to Section 6.6.4).
6.3 1982 DREDGED MATERIAL CONTAINMENT AREA REMEDY
IMPLEMENTATION
If implemented, material consolidation at the DMCA will raise the elevation of the area by
approximately 6 to 8 feet. Design of the DMCA consolidation area and engineered surface
will consider this, and will be constructed in a manner that protects against contaminant
migration, including during flood events. According to existing maps, approximately
1,000 square feet (0.7 percent) of the DMCA along its southern boundary may lie within
the 100-year floodplain. The boundary of the 100-year floodplain will be surveyed as part
of the design process. Fill will not be placed in the 100-year floodplain, and the
construction of filled areas will protect the material from erosion with slope stabilization
construction techniques. The method for erosion protection of the containment barrier will
be determined in design, and may consist of a geotextile or similar reinforcement layers,
crushed rock, riprap, or other durable materials.
6.3.1 Environmental Covenants
An environmental covenant will be placed on the DMCA to implement institutional
controls. The institutional controls will require that surface improvements provide a barrier
to wildlife and that the area remain in industrial use. The design of the surface
improvements will be included in the Engineering Design Report (refer to Section 6.6.2).
If soil from the LL Apartments Parcel with dioxins/furans TEQ concentrations less than
100 pg/g TEQ is consolidated within the DMCA, the environmental covenant shall
describe the nature, volume, and location of that soil.
A draft environmental covenant will be submitted to Ecology for consideration with the
As-built Reports for the work (refer to Section 6.6.4).
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6.4 ENVIRONMENTAL ANALYSIS OF REMEDY IMPLEMENTATION
The State Environmental Policy Act (SEPA), Chapter 43.21C RCW is a State of
Washington law that is intended to ensure that project proponents consider the effects of
the project on the natural and human environment prior to taking action. SEPA
compliance is required for any state or local agency action. Per the SEPA process, SEPA
documents to evaluate possible effects of the project on the environment have been
completed and are presented in Appendix A.
The SEPA checklist provides a summary of the project description or remedial actions;
describes the site, environmental, and ecological conditions; site and adjacent land uses;
and describes the proposed measures to reduce or control erosion, to reduce or control
air emissions of construction equipment, and measures used during construction to
ensure that remedial actions do not adversely impact downgradient water quality.
Ecology review of the SEPA checklist and information presented in the RI/FS and in this
Cleanup Action Plan indicates a Mitigated Determination of Nonsignificance is warranted
for this site. The mitigation required is to minimize disturbance of plants on the Lora Lake
Parcel to the degree possible. Where plants are disturbed by excavation, the
environmental damage will be mitigated by replanting the excavated areas in accordance
with the NRMP.
6.5 COMPLIANCE MONITORING
In accordance with WAC 173-340-410, compliance monitoring will be conducted to
confirm that (1) human health and the environment are adequately protected, (2) the
remedial action has achieved the cleanup standards, and (3) the cleanup action remains
protective after cleanup standards have been met. The following sections describe the
methods for compliance monitoring for the three site parcels. Additional detail of the
proposed compliance monitoring will be included in a Compliance Monitoring Plan that
will be submitted by the Port to Ecology for approval prior to implementation of cleanup
actions to which the compliance monitoring requirements apply. The Compliance
Monitoring Plan may be submitted in phases if that is more appropriate to the schedule
for completion of the work.
6.5.1 Lora Lake Apartments Parcel Soil Excavation and DMCA Consolidation
Protection monitoring will be conducted during soil excavation at the LL Apartments
Parcel through implementation of an Ecology-reviewed Health and Safety Plan. The
Health and Safety Plan will describe personal protective equipment to be used by site
workers, required soil and air monitoring (including dust monitoring) to document worker
and public safety, and site controls to restrict contact with contaminated material.
Protection monitoring will also include site controls and inspections to monitor that
pollution prevention measures are implemented during remedial construction to ensure
compliance with the NPDES discharge requirements, and includes erosion and sediment
control and stormwater management BMPs.
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Performance monitoring will be conducted prior to implementation of soil excavation at
the LL Apartments Parcel, and will consist of the collection of confirmation soil samples
to delineate the vertical and horizontal extent of soil excavation. Soil sample locations will
be surveyed by a licensed surveyor, and excavation will be conducted to the extents
determined by this soil sampling and surveying. This pre-excavation monitoring approach
will be used to avoid open excavations during the multi-week laboratory turnaround time
required for dioxins/furans analysis.
Confirmational monitoring at the LL Apartments Parcel and DMCA will be performed to
verify wildlife barrier integrity and performance (through effective isolation of the
underlying soils). Wildlife barrier inspections will be performed to verify the physical
integrity of the barriers. Monitoring activities and objectives will include visual inspection
of barrier conditions to ensure that the barrier is intact and coverage has been maintained
(i.e., underlying existing soil is not exposed).
LL Apartments Parcel and DMCA wildlife barrier physical integrity inspections or
confirmational monitoring will be conducted annually, or as otherwise directed by Ecology.
Additional barrier physical integrity inspections may be completed if one of the following
occurs and is thought to have potentially adversely impacted the integrity of the barrier: a
storm event that may have led to a barrier failure, such as erosion or a landslide; a site
use accident, such as a substantial barrier penetration or spill; a seismic event where
structural damages have been realized within the Port; or as otherwise determined
necessary by Ecology.
6.5.2 Lora Lake Parcel Shallow Soil Cleanup Area Excavation
Protection monitoring will be conducted during soil excavation at the LL Parcel consistent
with the methods described above for soil excavation at the LL Apartments Parcel.
The true mean remaining soil concentration will be calculated and compared to cleanup
levels per WAC 173-340-740(7)(d) and (e) and the Statistical Guidance for Ecology Site
Managers (Ecology 1992). The Statistical Guidance provides that for relatively small
compliance monitoring sample sizes (number of samples less than 30), not more than
20 percent of the samples should exceed a cleanup level based on the 90th percentile
value, which is the relevant value for cleanup levels based on background data sets. The
current available sample locations are considered adequate to identify the areas that are
required to be excavated to bring the true mean soil dioxins/furans TEQ concentration in
this area to concentrations less than 5.2 pg/g. The areas will be excavated to the extent
shown in Figure 4.2, and confirmed by survey. Following excavation, soil samples will be
collected from the excavation base at 6 feet bgs and at the western sidewall abutting the
Des Moines Memorial Drive paved sidewalk to document any concentrations of
dioxins/furans remaining in place at the conditional POC, or beneath the right-of-way.
Environmental covenants will be necessary if the soil samples collected at 6 feet bgs
contain COCs in excess of cleanup levels. Environmental convenants will be placed, if
needed, that require excavation of soil in the right-of-way or deeper than 6 feet be properly
managed to protect ecological receptors against exposure to excavated soil.
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Confirmational monitoring at the LL Parcel Shallow Soil Cleanup Area will consist of longterm
monitoring to ensure soil stability of the area, and compliance with environmental
covenants and institutional controls. This monitoring will be conducted as part of the
Ecology periodic review process.
6.5.3 Groundwater
Performance monitoring to confirm that the remedial action has attained groundwater
cleanup levels will be conducted through quarterly groundwater monitoring of wells
located upgradient, downgradient, and within the current extent of the contaminated
groundwater plume at the Site (limited to the LL Apartments Parcel central source area).
Groundwater at the LL Parcel and DMCA do not exceed groundwater cleanup levels;
therefore, monitoring of these parcels is not required for groundwater remedy
performance monitoring. Groundwater sampling conducted for sediment remedy
performance monitoring is described in the next section. Well locations, analytes, sample
methodology, and other details will be described in the Compliance Monitoring Plan.
Groundwater remedy performance monitoring will be discontinued when four consecutive
sampling events comply with the groundwater cleanup standards for all groundwater
COCs.
6.5.4 Lora Lake Parcel Sediment Cleanup Area (Future Wetland Soils)
During remedy construction, Protection monitoring will be conducted consistent with that
described above for the LL Apartments Parcel and LL Parcel Shallow Soil Cleanup Area
excavations.
Performance monitoring during cap placement and wetland filling will be conducted to
document that the required fill extent and thickness have been achieved. Sampling of the
fill material as placed will also be required to document that the organic carbon content
of the sand cap is in compliance with the remedial design.
Following remedy implementation, compliance monitoring of the sediment remedy will be
performed to assess whether contamination from the isolated and immobilized Lora Lake
sediment is migrating through the sediment cap. Groundwater samples will be collected
just above the sediment cap and between the former lake footprint and Miller Creek to
assess whether contaminants are moving from the isolated Lora Lake sediment.
Confirmational monitoring data for dioxins/furans and arsenic will be evaluated for
statistical difference from a set of upgradient site vicinity background samples collected
from within Port-owned property, or the public right-of-way. The sediment cap is designed
to achieve compliance with surface water quality criteria at the cap surface. The surface
water quality criteria of 0.005 pg/L dioxins/furans TEQ is significantly less than laboratory
practical quantitation limits of approximately 3.5 pg/L dioxins/furans TEQ. Data from
upgradient and cross-gradient groundwater wells indicate that the background
groundwater concentrations of dioxins/furans in the vicinity of the Site currently exceed
the practical quantitation limit. Similarly, arsenic is a known regional background
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Department of Ecology Lora Lake Apartments Site
contaminant and has been detected in upgradient and cross-gradient groundwater wells.
This statistical comparison method for confirmational monitoring samples provides a
measurable method to determine if samples collected immediately above the sediment
cap are different than samples collected from upgradient locations. This would be a direct
indication of cap performance. The upgradient site vicinity background data set will
contain a minimum of 20 samples, collected from 4 upgradient site vicinity wells during
each 5-year periodic review period, sampled concurrently with the confirmational
monitoring wells discussed below. Confirmational monitoring data will be statistically
compared to this site vicinity background data set.
Confirmational monitoring will be conducted annually for the first 5 years after wetland
construction, and concurrent with quarterly groundwater monitoring events if possible.
The first 5-year periodic review will assess the appropriate monitoring frequency for the
next 5 years, and subsequent 5-year periodic reviews will set the frequency for the
following five-year period. Confirmational monitoring samples will be collected from four
locations across the sediment cap, and from no more than four additional locations
between the former lake footprint and Miller Creek to be determined after the wetland has
been designed. The sampling locations, and the sample depth will depend upon the final
cap design, and will be determined by Ecology in conjunction with wetland design, and
specified in the Compliance Monitoring Plan. The chemicals to be analyzed for will be the
sediment contaminants the cap design addresses: arsenic and dioxins/furans.
The Compliance Monitoring Plan will include contingency actions to be taken if sediment
cap breakthrough from the isolated Lora Lake sediment occurs as identified by the
statistical evaluation or other information made known to Ecology. The Compliance
Monitoring Plan will include conditions under which a contingency action will occur. If
elevated COC concentrations are detected, the Port, in coordination with, and at the
direction of, Ecology, will determine what contingency actions may be necessary and
appropriate. Although not used for evaluation of sediment cap performance, the Site
groundwater cleanup level of 6.7 pg/L is applicable throughout the Site, including at the
LL Parcel. Detections of dioxins/furans in confirmational monitoring locations that exceed
the Site groundwater cleanup level would require contingency action regardless of the
results of the statistical comparison to the site vicinity background data set.
Contingency actions that will be considered for inclusion in the Compliance Monitoring
Plan include the following:
Resampling of the site vicinity background and confirmational monitoring points
to increase the size of the data set and, therefore, the power of the statistical
comparison.
More frequent monitoring to assess whether potential impacts rise to a level
that requires a further contingency response.
Adding sample locations to better assess the occurrence of cap breakthrough.
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Department of Ecology Lora Lake Apartments Site
Addition of more organic carbon to the subsurface through appropriate means
such as injection through borings or other methods identified when the nature
of the breakthrough is known.
Other contingency actions identified during Compliance Monitoring Plan
development.
Contingency actions identified at the time cap breakthrough is identified, as
approved by Ecology.
Ecology will consider the net environmental benefit of any proposed response action that
involves significant disturbance of the mitigation area. Implementation of any proposed
response actions that involve significant disturbance of the mitigation area must be
authorized by the USACE and Ecology as required by the Restrictive Covenant that
applies to the Miller Creek/Lora Lake/Vacca Farm Wetland and Floodplain Mitigation Area
(Port of Seattle 2003).
More frequent monitoring using techniques in the approved Compliance Monitoring Plan
(to be developed) will not be considered to involve significant disturbance of the mitigation
area. Adding sample locations using techniques that do not involve significant vegetation
disturbance also will not be considered to involve significant disturbance of the mitigation
area. Approved techniques are to be included in the Compliance Monitoring Plan and
may depend upon the final design of the wetland.
6.6 REQUIRED FOLLOW-ON DOCUMENTATION
6.6.1 Financial Assurances
The Port will provide Ecology with a cost estimate for implementation of the Consent
Decree and will provide proof of financial assurances that the Port has sufficient financial
resources available and in place of the sufficient amount to cover all costs associated
with the operation and maintenance of the cleanup action, including institutional controls,
compliance monitoring, and corrective measures (refer to WAC 173-340-440(11)).
6.6.2 Plans Describing the Cleanup Action
Plans describing Ecology's selected remedy will be prepared as required by WAC 173-
340-400(4). The plans to be prepared are an Engineering Design Report, Construction
Plans and Specifications, and an Operation and Maintenance Plan. These plans may be
prepared in phases as appropriate and as approved by Ecology.
Once approved by Ecology, these plans become integral and enforceable parts of the
Consent Decree.
The Operations and Maintenance Plan is to include an inspection schedule for the
barriers to wildlife, pre-approved means of repair, and pre-approved procedures for
removing the barrier for needed subsurface work and replacing it when the work is done.
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Department of Ecology Lora Lake Apartments Site
It is also to include pre-approved designs for future work such as landscaping units and
subsurface infrastructure, such as storm drains and underground utilities that may be
installed subsequent to the completion of cleanup construction. Use of pre-approved
procedures requires Ecology be notified 30 days in advance of work, and submittal of Asbuilt
Reports at the completion of work. Work that does not follow pre-approved
procedures requires prior approval from Ecology.
If future work is proposed that does not follow a pre-approved plan, Ecology should be
contacted as early as possible to discuss the work and the time frame for review and
approval.
The Operations and Maintenance Plan is to include a description of the minimum scope
of Periodic Reviews required for the Site, a template for the Periodic Review report, and
a description of the Port submittal of a 5-year report of post-cleanup site conditions and
monitoring data. All work performed during the 5-year review period must be summarized
in the Periodic Review.
6.6.3 Permits, Approvals, and Substantive Requirements
Permits and approvals and any substantive requirements for exempted permits, if
required for construction or to otherwise implement the cleanup action, shall be identified
and, where possible, be resolved before or during the design phase to avoid delays during
construction and implementation of the cleanup action (WAC 173-340-400(5)).
The permits, approvals, and substantive requirements that are known at this time to apply
to the selected cleanup action are listed in Exhibit D of the Consent Decree. Ecology and
the Port have a continuing obligation to determine whether additional permits or approvals
addressed in RCW 70.105D.090(1) would otherwise be required for the remedial action
under the Consent Decree. In the event that either Ecology or the Port determines that
additional permits or approvals are required for the remedial action, they shall promptly
notify the other party of the determination. The substantive requirements and necessary
permits will be identified and included in the Engineering Design Report or obtained by
the cleanup construction contractor prior to the beginning of any work that requires them.
Once approved by Ecology, these requirements become integral and enforceable parts
of the Consent Decree.
The USACE has approval authority regarding activities in the Lora Lake Parcel since it is
within the habitat mitigation area. The USACE has advised Ecology that it agrees in
concept with remediation of Lora Lake sediment through filling and subsequent
rehabilitation of the former wetland, and remediation of Lora Lake shallow soil by
excavation, backfilling, and habitat restoration. The USACE has also advised Ecology
that it can only formally approve such actions after conducting a full review of the project
design and its potential effect on aquatic resources and the mitigation area. USACE
anticipates simultaneously making a Nationwide Permit 38 decision and approving
implementation of the remediation at the Lora Lake Third Runway mitigation area.
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6.6.4 Construction Documentation
Construction documentation will be prepared as required by WAC 173-340-400(6).
Project As-built Reports will be prepared, meeting the requirements of WAC
173-340-400(6)(ii). As-built Reports may be prepared in phases, as approved by Ecology.
A draft environmental covenant for the area in which work was conducted will be
submitted for Ecology review and approval with the As-built Reports.
6.6.5 Compliance Monitoring Plan
A Compliance Monitoring Plan will be prepared as required by WAC 173-340-410. The
Compliance Monitoring Plan shall include contingency actions to be taken if monitoring
indicates cleanup standards have not been attained.
Once approved by Ecology, the Compliance Monitoring Plan becomes an integral and
enforceable part of this Consent Decree.
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7.0 Schedule
7.1 IMPLEMENTATION SCHEDULE
The schedule for major deliverables and work tasks associated with remedial actions at
the Site is included as Exhibit C to the Consent Decree. The schedule provides
anticipated submittal dates or task durations for deliverables and actions associated with
site cleanup, including monthly progress reports, financial assurances, remedial design
and engineering documents, and As-built Reports. The schedule included in Exhibit C
may be amended in the future at the Port's request with approval from Ecology to
coordinate cleanup activities with other construction work anticipated in the Site vicinity,
such as City of Burien stormwater infrastructure improvement projects, SR-518 off ramp
construction, or STIA-related construction. Refer to Exhibit C for details on project
deliverables and schedule.
In addition to the tasks detailed in the project schedule in Exhibit C, the following schedule
requirements apply to work at the Site:
All analytical data collected at the Site must be submitted to Ecology's
Environmental Information Management (EIM) System within 30 days of
receipt of validated data.
Health and Safety Plans for all on-site activities must be developed prior to
mobilization to the field. The Health and Safety Plans will be submitted to
Ecology for review and comment. Ecology does not approve Health and Safety
Plans. The Health and Safety Plans must be consistent with
Chapter 49.17 RCW and regulations adopted under that authority (refer to
WAC 173-340-810(2))
7.2 CONSTRUCTION PHASING AND SEQUENCING
Remedy implementation at the Site may be conducted as a single project or as phased
construction, dependent on Port development decisions and schedule. Any phasing will
be conducted within the schedule presented in Exhibit C of this Consent Decree. Any
projects planned for completion within the LL Apartments Site will require coordination
and approval from Ecology prior to implementation.
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Department of Ecology Lora Lake Apartments Site
8.0 References
Aspect Consulting. 2010. Geology/Hydrogeology Technical Memorandum-Lora Lake
Apartment Parcel Remedial Investigation/FS Work Plan Addendum. July.
Aspect Consulting and S.S. Papadopulos. 2008. Seattle-Tacoma International Airport:
Phase I Groundwater Study Report. Prepared for Port of Seattle. July.
Cowardin, L.M., Carter, V., Golet, F.C. and La Roe, E.T. 1979. Classification of Wetlands
and Deepwater Habitats in the United States. U.S. Dept. Interior, Fish & Wildlife
Service, FWS/OBS-79/31.
Floyd|Snider. 2013. Lora Lake Parcel Soil Sampling Results. Memorandum to
David South, Washington State Department of Ecology. REVISED September 9,
2013.
_____. 2015a. Lora Lake Apartments Site Remedial Investigation/Feasibility Study.
Prepared for Port of Seattle. 16 January.
_____. 2015b. Demonstration of Groundwater Protection of Surface Water Beneficial
Uses. Technical Memorandum. 11 March.
Parametrix, Inc. (Parametrix). 2001. Natural Resource Mitigation Plan Seattle-Tacoma
International Airport Master Plan Update Improvements. Prepared for the Port of
Seattle. November.
Port of Seattle. 2003. Declaration of Restrictive Covenants (Miller Creek/Lora Lake/Vacca
Farm Wetland and Floodplain Mitigation Area). #20030312001777.
_____. 2005. Seattle-Tacoma International Airport-Wildlife Hazard Mitigation and
Conservation Plan.
_____. 2011. 2010 Wetland Mitigation Monitoring Report, Port of Seattle MPU Natural
Resource Mitigation. Prepared by Port of Seattle, Aviation Division, Seattle,
Washington. April.
U.S. Department of Transportation (USDOT) FAA. 1989. Airport Design Advisory
Circular.
Washington State Department of Ecology (Ecology). 1992. Statistical Guidance for
Ecology Site Managers. Publication 92-54. Toxics Cleanup Program. August.
_____. 2007. Model Toxics Control Act Chapter 70.105D RCW. Publication No. 94-06.
Revised November.
. 2009. Agreed Order No. DE-6703 issued to the Port of Seattle.
Revised Draft Cleanup Action Plan
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Department of Ecology Lora Lake Apartments Site
. 2010. Department of Ecology Technical Memorandum #8 re: "Natural
Background for dioxins/furans in WA soils." 28 April.
. 2011. Urban Seattle Area Soil Dioxin and PAH Concentrations Initial Summary
Report. Publication No. 11-09-049. September.
. 2012. Stormwater Management Manual for Western Washington. Publication
Number 12-10-030. August.
Washington State Department of Ecology, U.S. Army Corps of Engineers Seattle District,
and U.S. Environmental Protection Agency Region 10 (Ecology et al.). 2006. Wetland
Mitigation in Washington State Part 1: Agency Policies and Guidance (Version
1). Washington State Department of Ecology Publication #06-06-011a. Olympia,
Washington.
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Tables
Lora Lake Apartments Site
Table 3.1
Soil and Groundwater Cleanup Levels
Cleanup Level Remediation Cleanup/Remediation Level
1
Contaminant of Concern Pathway Cleanup Level Source/Reference Value Level Unit Applies
Metals
Human healthdirect contact and protection of groundwater, adjusted for Lora Lake Apartments Parcel
MTCA Method AUnrestricted Land Use 20 NA mg/kg
natural background for soil and Lora Lake Parcel
Arsenic
MTCA Method CStandard, CarcinogenIndustrial
Human healthdirect contact (ingestion only) 88 NA mg/kg DMCA
Land Use
Terrestrial Plants and Animals MTCA Ecological Indicator Soil Concentrations 50 NA mg/kg Lora Lake Parcel
Lead Human healthdirect contact, prevention of unacceptable blood lead
MTCA Method AUnrestricted Land Use 250 NA mg/kg Lora Lake Apartments Parcel
levels
Human healthdirect contact (ingestion only) MTCA Method A Industrial Land Use 1,000 NA mg/kg DMCA
Total Petroleum Hydrocarbons
Human healthprotection of groundwater for non-carcinogenic effects
Gasoline Range Hydrocarbons MTCA Method AUnrestricted Land Use 2
100 NA mg/kg Site-wide
during drinking water use and Protection of Terrestrial Plants and Animals
Lora Lake Apartments Parcel
Prevention of accumulation of free product in groundwater MTCA Method AUnrestricted Land Use 2,000 NA mg/kg
5
Sum of Diesel and Heavy Oil and DMCA
Range Hydrocarbons
Terrestrial Plants and Animals MTCA Ecological Indicator Soil Concentrations 200 NA mg/kg Lora Lake Parcel
Semivolatile Organic Compounds
Lora Lake Apartments Parcel
Soils MTCA Method BStandard, Carcinogen 2,500 NA g/kg
and Lora Lake Parcel
Pentachlorophenol Human healthdirect contact (ingestion only)
MTCA Method CStandard, CarcinogenIndustrial
330,000 NA g/kg DMCA
Land Use
Lora Lake Apartments Parcel
MTCA Method BStandard, Carcinogen 137 NA g/kg
and Lora Lake Parcel
cPAHs TEQ Human healthdirect contact (ingestion only)
MTCA Method CStandard, CarcinogenIndustrial
18,000 NA g/kg DMCA
Land Use
Volatile Organic Compounds
Lora Lake Apartments Parcel
MTCA Method BStandard, Non-carcinogen 8,000 NA mg/kg
and Lora Lake Parcel
Ethylbenzene Human healthdirect contact (ingestion only)
MTCA Method CStandard, CarcinogenIndustrial
350,000 NA mg/kg DMCA
Land Use
Lora Lake Apartments Parcel
MTCA Method BStandard, Non-carcinogen 6,400 NA mg/kg
and Lora Lake Parcel
Toluene Human healthdirect contact (ingestion only)
MTCA Method CStandard, CarcinogenIndustrial
280,000 NA mg/kg DMCA
Land Use
Dioxins/Furans
Human healthdirect contact (ingestion only) MTCA Method BStandard, Carcinogen 13 100 pg/g Lora Lake Apartments Parcel
MTCA Method CStandard, CarcinogenIndustrial
Human healthdirect contact (ingestion only) 1,700 NA pg/g DMCA
Dioxins/Furans TEQ Land Use
Natural Background for Dioxins/Furans in Washington Soils
Terrestrial Plants and Animals 5.2 NA pg/g Lora Lake Parcel
3
Technical Memorandum (WSDOE 2010)
Revised Draft Cleanup Action Plan
Page 1 of 2 Table 3.1
Lora Lake Apartments Site
Table 3.1
Soil and Groundwater Cleanup Levels
Cleanup Level Remediation Cleanup/Remediation Level
1
Contaminant of Concern Pathway Cleanup Level Source/Reference Value Level Unit Applies
Metals
Arsenic Washington state background MTCA Method A 5 NA g/L Site-wide
Total Petroleum Hydrocarbons
Gasoline Range Hydrocarbons MTCA Method AUnrestricted Land Use 2
1,000 NA g/L Site-wide
Groundwater Human healthprotection of groundwater for non-carcinogenic effects
Sum of Diesel and Heavy Oil during drinking water use MTCA Method AUnrestricted Land Use 500 NA g/L Site-wide
Range Hydrocarbons
Semivolatile Organic Compounds
Pentachlorophenol Human healthdrinking water beneficial use State and Federal MCL 1 NA g/L Site-wide
cPAHs TEQ Human healthdrinking water beneficial use MTCA Method BStandard, Carcinogen 0.12 NA g/L Site-wide
Dioxins/Furans
Dioxins/Furans TEQ Human healthdrinking water beneficial use 4
MTCA Method BAdjusted, Carcinogen 6.7 NA pg/L Site-wide
Notes:
1 The most stringent applicable cleanup levels for the complete human health pathways are identified for the Lora Lake Apartments Site.
2 Gasoline range hydrocarbons cleanup levels for soil and groundwater are based on the higher cleanup level as testing indicated that benzene was not present.
3 As presented in the WSDOE 2010 technical memorandum, the Washington state natural background concentration of 5.2 pg/g TEQ is calculated as the lower of the 90th percentile and 4 50 percentile (per WAC 173-340-709). Refer to Appendix M of the Lora Lake Apartments Site Remedial
Investigation/Feasibility Study for more details.
4 -5
Cleanup level is Adjusted MTCA Method B value for Protection of Human Health for Consumption of Drinking Water calculated using adjusted MTCA Method B per MTCA Equation 720-2 (with a risk level of 10 ).
5 The MTCA Method A Unrestricted Land Use cleanup level is applied to the DMCA because no MTCA Method C Industrial cleanup level is available for use.
Abbreviations:
CPOC Conditional Point of Compliance
cPAH Carcinogenic polycyclic aromatic hydrocarbon
DMCA Dredged Material Containment Area
MCL Maximum Contaminant Level
g/kg Micrograms per kilogram
g/L Micrograms per liter
mg/kg Milligrams per kilogram
MTCA Model Toxics Control Act
NA Not available
pg/g Picograms per gram
pg/L Picograms per liter
TEQ Toxicity Equivalent
WAC Washington Administrative Code
WSDOE Washington State Department of Ecology
Revised Draft Cleanup Action Plan
Page 2 of 2 Table 3.1
Lora Lake Apartments Site
Table 5.1
Cleanup Alternatives Considered for the Lora Lake Apartments Parcel
Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5
$4.7 million $6.1 million $7.1 million $7.7 million $9.2 million
Excavation and off-site
Excavation and off-site Excavation and off-site disposal of soil >
Excavation and off-site
disposal of soil disposal of soil 100 pg/g dioxins/furans.
No excavation disposal of soil > 13 pg/g
> 1,000 pg/g > 100 pg/g Consolidation of soil 13
dioxins/furans
dioxins/furans dioxins/furans 100 pg/g dioxins/furans at
DMCA
Capping of consolidation
Capping < 1,000 pg/g Capping < 100 pg/g
Capping all area with soil < 100 pg/g Barrier to wildlife
dioxins/furans dioxins/furans
dioxins/furans
Groundwater
Groundwater treatment
monitoring and Groundwater treatment by source removal; Groundwater monitoring
by source removal
management
Environmental
Environmental Covenants to restrict to commercial land use and require cap maintenance Covenants for barrier to
wildlife
All alternatives include drain system improvements to prevent entry of contaminated groundwater or soil
Note:
Bold Selected for implementation (refer to Figure 5.2).
Abbreviations:
pg/g picograms per gram
RPZ Runway Protection Zone
Page 1 of 1 Revised Draft Cleanup Action Plan
Table 5.1
Lora Lake Apartments Site
Table 5.2
Cleanup Alternatives Considered for the Lora Lake Parcel
Alternative 1 Alternative 2 Alternative 3 Alternative 4
$0.4 million $3.3 million $4.3 million $7.3 million
Fill the lake to rehabilitate it
to a wetland system. This
Engineering controls 1.5-foot sand cap with 0.06%
action will result in the
to control sediment organic carbon content to Dredging and off-site
conversion of the existing
LAKE and fish movement contain contaminated sediment disposal of contaminated
lake sediment and open
from Lora Lake to in place and provide a clean sediment.
water conditions to a
Miller Creek. surface for benthic biota.
palustrine scrub-shrub
wetland.
Soil excavation. Excavation
Control risk to
extent will consider Excavation and off-site
SOIL workers with Capping.
resource mitigation area disposal.
institutional controls.
harm.
Environmental
Covenants to Environmental Covenants to Environmental covenants to
maintain engineering maintain cap and keep in maintain restoration and
controls and keep in current land use. keep in current land use.
current land use.
Note:
Bold Selected for implementation.
Page 1 of 1 Revised Draft Cleanup Action Plan
Table 5.2
Figures
1,260,000 1,270,000 1,280,000
190,000 190,000
180,000 Puget 180,000
Sound
Lora Lake 1982 Dredged Material
Apartments Parcel Containment Area
Lora Lake
Parcel
170,000 170,000
Area
Enlarged
^_
W A S H I N G T O N
Notes:
160,000 Basemap provided by Esri, 2014.
Coordinate grid presented in North American
Datum 1983 High Accuracy Reference 160,000
Network. State Plane Coordinate System,
Washington North Zone, in units of Survey 0 1 2
Feet. Map Projection = Lambert Conformal
Conic. Scale in Miles
Cleanup Action Plan
Lora Lake Apartments Site Figure 1.1
Burien, Washington Site Vicinity Map
Esri, HERE, DeLorme, MapmyIndia, OpenStreetMap contributors,
and the GIS user community
I:\GIS\Projects\POS_LLA\MXD\CleanupActionPlan - T1140\Figure 1.1 Site Vicinity Map.mxd
12/1/2014 REVISED DRAFT
1,271,500 1,272,000 1,272,500 1,273,000 1,273,500
SR 518 CITY OF BURIEN 175,000
CITY OF SEATAC
175,000
LORA LAKE
Legend
APARTMENTS 1982 DREDGED
City Boundary AVE SOUTH PARCEL MATERIAL
Tax Parcel TH CONTAINMENT
8
Approximate Extent of 1982 Dredged AREA
300 Material Containment Area
Approximate Location of Fences
Runway Protection Zones1
SOUTH 150TH STREET
Controlled Activity Area 2
Extended Object Free Area 3 174,500 174,500
Notes:
1. Runway Protection Zones (RPZs) based on
Port of Seattle data.
2. The Controlled Activity Area is the zone outside FORMER SEATTLE PORT OF
of and adjacent to the Extended Object Free CITY LIGHT SEATTLE
Area (XOFA) in which land use is restricted by
the Federal Aviation Administration (FAA) and PROPERTY PROPERTY
excludes the construction of residences and
public gathering places such as shopping
centers, offices, or hospitals (FAA 2008).
3. The XOFA must be kept clear of objects PORT OF
including structures, equipment, and terrain, DES MOINES MEMORIAL DRIVE
L o r a
except for those objects necessary for air SEATTLE
navigation or aircraft ground-maneuvering
PROPERTY L a k e
purposes. (FAA 2008).
Tax parcel boundaries based on King County
tax parcel data.
City boundary data provided by King County.
Locations of fences were digitized based on STIA 3RD RUNWAY
aerial image cited below and Google Earth
Street View. CITY OF BURIEN APPROACH
LIGHTING SYSTEM
Aerial image provided by Port of Seattle
and dated March 20, 2011.
Coordinate grid presented in North American
174,000 Datum 1983 High Accuracy Reference
Network. State Plane Coordinate System,
LORA LAKE
Washington North Zone, in units of Survey CITY OF SEATAC 174,000
PARCEL
Feet. Map Projection = Lambert Conformal
Conic.
Abbreviation:
FAA = Federal Aviation Administration
0 150 300
Scale in Feet
Cleanup Action Plan
Figure 2.1
Lora Lake Apartments Site
Site Area Map
Burien, Washington
I:\GIS\Projects\POS_LLA\MXD\CleanupActionPlan - T1140\Figure 2.1 Site Map.mxd REVISED DRAFT
3/20/2015
1,272,000 1,272,500 1,273,000 1,273,500
328
302 296 308
Legend 324 300
320
322 324
320
328
326 324 310
328
300 320 Topographic Contour (NAVD88) 332
334 316 316 292
318 SR 518
175,000 314
Tax Parcel
298
302 300
Approximate Extent of 1982 Dredged 308
330 328 175,000
306 294
Material Containment Area 318
316
310
296
326 322
282
304 282
334
Notes: 292 286
320
332 282
282
Topographic contours derived from Bare-Earth 284
316
290 284 318
294
Return LiDAR data provided by the Puget Sound 312 280
304 294 284
LiDAR Consortium. 300 292 286 276
Topographic contours presented in units of feet 302 286
relative to NAVD88. 282 282
292 288
Tax parcel boundaries based on King County 302 290 312
310tax parcel data. 304 310 314
292 276
302
Aerial image provided by Port of Seattle and dated 280 286
March 20, 2011. 306 LORA LAKE 282 278
310 280
Coordinate grid presented in North American Datum 306
308
APARTMENTS 298 276
288 278
278
302
1983 High Accuracy Reference Network. State 304 294 288
PARCEL 296 290 284 276
280 282
Plane Coordinate System, Washington North Zone, 308 296 294
1982 DREDGED MATERIAL 280 286 278
in units of Survey Feet. Map Projection = Lambert 308 292 CONTAINMENT AREA 280 284
Conformal Conic. 280 278
308 300
308 Abbreviation: 302 298 290 276
NAVD88 = North American Datum 1988 300 288 280
304 308
308 300 280
282 278
SOUTH 150TH STREET 286 278 278
298 280
278 272
174,500 AVE SOUTH 306 310 286 280
302 276
284 280 280
304 284 286 286 174,500
316 282 274
318 274
274 272
288 274
276 272 276
272
326
276
280
TH 274
270 274
272
8
274 282 278 274
282
280 282
296 274 294 274
300 272
328 288 270 274
276 278
274 274
330 DES MOINES MEMORIAL DRIVE 272 272
302 290 276 278
PORT OF
272
L o r a 270
SEATTLE 274
326 274 L a k e
308
PROPERTY 272 272
276 272
328 270 PORT OF
312 272 SEATTLE
270
PROPERTY
310 276 270 270 272
272 272 272
272
270 274
306 274 270 276 274 276
270 274
300 270
LORA LAKE 270 280
174,000 270
280 174,000
PARCEL 278
272 272
268
280 280 276 278
270 270
288
272 268 268
296 274 272 270 272 270 282
276 270 268 284
274 282
0 150 300 268 286
282 286 284
284 286 284
280
Scale in Feet 268
286
268 270 276 286 288
288
284 274 292
290
276 278 290
282 270 268 292
294
Cleanup Action Plan Figure 2.2
Lora Lake Apartments Site Site Topography
Burien, Washington
I:\GIS\Projects\POS_LLA\MXD\CleanupActionPlan - T1140\Figure 2.2 Topography of LLA & LL & DMA.mxd
12/1/2014 REVISED DRAFT
1,260,000 1,270,000 1,280,000
3 5
Legend M
SW ROXBURY ST
T H Y D
S W E E
W S S
Miller Creek SW 102ND ST
190,000 R
AV S M
O
E E S E S W
I W E
Lora Lake N
A V AV E
A AV 190,000
SW 106TH ST
Y
Miller Creek Drainage Basin SW 108TH ST S IN G
E
O
B
H E S
W S S H M
Boundary T T H D
R
C
A
E 8 T 2 8 AV S 1 6 E E S W V T A M
City Boundaries H S
T
2
1 T
1
S O 2 1 S T AV 1 S S I R Tukwila
V E
SW 116TH ST
L A Properties of Interest
1 2 T H A D
State Highway R
5 H T S
Major Road
Notes: S 124TH ST 99 SR
Tax parcel boundaries based on King County
tax parcel data. M
City boundaries, Miller Creek alignment, and SW 128TH ST
S 128TH ST I L I 180,000 A M drainage basin GIS data provided by King
B T A
County. A U
Aerial image provided by National Agriculture R Y M
Imagery Program (NAIP) and dated 2011. S W 13 6 T H
S 136TH ST R 180,000
B
Coordinate grid presented in NAD 1983 HARN
S T D L
State Plane Coordinate System, Washington
V North Zone, in units of Survey Feet. S
Map Projection = Lambert Conformal Conic. D 1982 Dredged Material
Abbreviations: S W Lora Lake Containment Area
HARN = High Accuracy Reference Network Apartments Parcel
NAD = North American Datum
SW 152ND ST
S 154TH ST S
V U
W 1 5 6 T H 518
S S T
Lora Lake
E Burien
S 1 6 0 T H
AV S T
170,000 D W
L Lora Lake
I S
W D Parcel I A
E
R
L R 170,000
P
R
A k
E e
e
M T
r C
S S C
W E A
r
1
7 V R
2
N L
l l e
D Y
S i G
T S
M O
Normandy R
D
S 176TH ST
P u g e t Park SeaTac
S o u n d
SR 509 S 188TH ST
160,000 S 192ND ST
V U S
D
509 R 160,000
S
Y
R D
A
S 200TH ST
T R
I
L
I A
0 2,000 4,000 8,000 M I
L
L
I
Scale in Feet R
O
Cleanup Action Plan Figure 2.3
Lora Lake Apartments Site Miller Creek
Burien, Washington Watershed Map
I:\GIS\Projects\POS_LLA\MXD\CleanupActionPlan - T1140\Figure 2.2 Miller Creek Watershed Map.mxd
12/1/2014 REVISED DRAFT
1,272,000 1,272,500 1,273,000
175,000 SR 518 175,000
Legend
Former Location of Structure Associated
with Industrial Activity1
Location of Former Residence and
Associated Outbuilding1
Approximate Perimeter of Former
Auto Wrecking Yard
Approximate Extent of Investigation
Potential Drum Cleanout Pond (1946 Aerial)
by GeoScience Management, Inc. 4
Tax Parcel
Historical Golder Excavation (1987)
Approximate Excavation Limit (Golder)3
Concrete Sump Approximate Location of Concrete Sump (Golder)
Phase 1 Excavation Limit
Former Seattle City Light Sunnydale Substation
Extent of Concrete Slab (Removed) Approximate Location of Novak
Barrel Cleaning Company Building
Extent of Substation Fenceline Potential Drum
Cleanout Pond 2
Extent of Soil Excavation SOUTH 150 TH STREET DES MOINES MEMORIAL DRIVE
Notes:
1. Locations of former residences and former structures
174,500 AVE SOUTH
associated with auto wrecking and barrel cleaning TH
activities were digitized using reference aerial photos 8 174,500
dated 1936, 1946, 1980, and 1985 (Appendix A of
the RI/FS).
Concrete Slab
2. Approximate location of Potential Drum Cleanout Pond
based on 1946 aerial photograph (Appendix A of the (Removed) Approximate Perimeter of
RI/FS). Former Auto Wrecking Yard
3. Approximate location of the 1987 excavation and sump Former Perimeter Fence
removal by Golder Associates (Golder 1987).
4. Approximate Extent of Investigation by GeoSciences of Seattle City Light
Management, Inc. supplied by AECOM, Inc. (AECOM 2009). Sunnydale Substation5
5. Approximate locations for features associated with the
former Sunnydale Substation are based on Figure 4
Area of Soil Excavation
(Pinnacle Geosciences 2009).
Tax parcel boundaries based on King County tax by Seattle City Light
parcel data.
Aerial image provided by Port of Seattle and dated
March 20, 2011.
Coordinate grid presented in North American Datum
1983 High Accuracy Reference Network. State
Plane Coordinate System, Washington North Zone,
in units of Survey Feet. Map Projection = Lambert L o r a
Conformal Conic. L a k e
0 100 200
Scale in Feet
Cleanup Action Plan
Figure 2.4
Lora Lake Apartments Site
Historical Site Uses and Operations
Burien, Washington
I:\GIS\Projects\POS_LLA\MXD\CleanupActionPlan - T1140\Figure 2.4 Historical Site Uses and Operations.mxd REVISED DRAFT
12/1/2014
Lora Lake
Apartments Parcel
Dredged Material
Containment Area
Port of
Seattle
Property
Legend
Lora Lake
Groundwater Point of
Compliance
Soil Point of Compliance
Sediment and Groundwater
Points of Compliance
Note:
Orthophoto provided by Esri, 2011.
0 25 50 100
Scale in Feet
Sou rce: Esri , D igitalGlob e, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, swi sstopo, and the GIS
Cleanup Action PlanUser Commu ni ty
Lora Lake Apartments Site Figure 3.1
Burien, Washington Points of Compliance
I:\GIS\Projects\POS_LLA\MXD\CleanupActionPlan - T1140\Figure 3.1 Points of Compliance.mxd
4/9/2015 REVISED DRAFT
&<
&<
&<
&<
&<
&<
4
&< &<
&<
&<
1 &<
&<
Legend 3
&<
6
& <
2
&<
&<
&<
&<
&<
&<
&<
TPH- &< 5
2
Area TPH-GRO DRO/HO PCP cPAH Lead
1 < CUL < CUL < CUL 1.16 < CUL
2 < CUL < CUL 6.00 1.09 1.48
3 < CUL < CUL 1.08 2.55 1.18
4 19.0 12.95 1.48 6.42 11.52
5 < CUL < CUL < CUL < CUL 1.16
6 < CUL < CUL < CUL < CUL 1.28
Cleanup Action Plan
Lora Lake Apartments Site
Burien, Washington
REVISED DRAFT
60,000
50,000
40,000
Excavation Soil Volume (cubic yards) 30,000
Excavation Soil Volume: 19,000 cubic yards
Dioxins/Furans TEQ Mass Concentration: 100 pg/g 1
20,000
Excavation Soil Volume: 8,800 cubic yards
Dioxins/Furans TEQ Mass Concentration: 1,000 pg/g 1 Notes:
1 The 100 pg/g and 1,000 pg/g dioxins/furans remedial action levels used for Alternatives 2, 3, and 4 were
selected by picking points on the curve where the majority of contaminant mass would be excavated, without
the volume being disproportionately high.
10,000 2 The dioxins/furans mass concentration points shown are the average concentrations for a contaminant area at
a particular depth. For example, the concentrations were averaged in the Central Source Area in the 0.5 to
2 feet bgs depth interval (1,810 pg/g and 21,200 pg/g) to get an average concentration of 11,500 pg/g.
3 There are 30,000 cubic yards of soil with dioxins/furans concentrations between 13 and 100 pg/g TEQ, and
19,000 cubic yards of soil with dioxins/furans concentrations exceeding 100 pg/g TEQ.
0
0 2,000 4,000 6,000 8,000 10,000 12,000
Dioxin/Furan TEQ Mass Concentration2 (pg/g)
Cleanup Action Plan Figure 3.3
Lora Lake Apartments Site Excavation Volume by
Burien, Washington Soil Concentration
F:\projects\POS-LLA\Task 1140 - CD and CAP Development\Consent Decree\REVISED DRAFT CD\Exhibit B - Cleanup Action Plan\Figures\Figure 3.3 Excavation Volume by Soil Concentration.docx REVISED DRAFT
Excavation Depth Excavation Depth
- 10 feet - 20 feet
Excavation Depth
- 1 foot
Excavation Depth
- 2 feet
1,272,000 1,272,500 1,273,000
Excavation Depth
00 00
SR 518 - 10 feet
5, 0 17 5, 0
17
Excavation Depth
- 20 feet
Excavation Depth LORA LAKE
- 1 foot APARTMENTS
Cleanup Area C PARCEL
TH S OU
Cleanup Area C
VE TH A 8
Cleanup Area B
C entral
Sou rce Are a Excavation Depth
- 2 feet
Legend Cleanup
Lora Lake Apartments Cleanup Areas Western Cleanup A r ea A Area B
Cleanup Area A Source Are a
Excavation Depth
Cleanup Area B - 1 foot
Cleanup Area C Cleanup A r e a C
Cleanup Area Boundary a
SOUTH 150TH STREET e
r
Source Area A
e A
c
Tax Parcel a
r
u e
00 r 00
o A
Approximate Location of Fences FORMER SEATTL E S
4, 5
3 p 4, 5
Notes: 0
0 CITY LIGHT n u
17 Excavation Depth r 17
e n
Cleanup Area A encompasses areas with a maximum PROPERTY t a
- 4 feet Excav ati on Depth s e
l
dioxins/furans TEQ concentration greater than a
E C
Excavation Depth
1,000 pg/g at any depth. - 1 0 feet
Cleanup Area B encompasses areas with a maximum - 1 foot
dioxins/furans TEQ concentration greater than 100 pg/g,
but less than 1,000 pg/g at any depth.
E
Cleanup Area C encompasses areas with a maximum Clea n u p V
I
dioxins/furans TEQ concentration greater than 13 pg/g, R
Area B D
but less than 100 pg/g at any depth. L
PORT OF A
Locations of fences were digitized based on aerial I
R
image cited below and Google Earth Street View. SEATTLE O
PROPERTY M
Aerial image provided by Port of Seattle and dated E
March 20, 2011. M
S
Tax parcel boundaries based on King County tax E
parcel data. N
I
O
Coordinate grid presented in North American Datum M L o r a
1983 High Accuracy Reference Network. State Plane S
E L a k e
Coordinate System, Washington North Zone, in units D
of Survey Feet. Map Projection = Lambert Conformal
Conic.
0 100 200
Abbreviations:
pg/g = Picograms Per Gram
Scale in Feet
TEQ = Toxic Equvalent Quotient
Cleanup Action Plan Figure 4.1
Lora Lake Apartments Site Lora Lake Apartments Parcel
Burien, Washington Cleanup Areas
I:\GIS\Projects\POS_LLA\MXD\CleanupActionPlan - T1140\Figure 4.1 Cleanup Areas.mxd
3/20/2015 REVISED DRAFT
Excavation Depth
- 1 foot
Excavation Depth
- 10 feet
Excavation Depth
- 4 feet
Excavation Depth
- 1 foot
1,272,500 1,273,000 1,273,500
LL APARTMENTS
PARCEL
00 00
w
o
l
4, 5 l a
a 4, 5
e
h
r
S
17 A 17
l
e p
c u
r n
a a
P e
l
L C
L
l
i
o
S
E
V
I
R
D
L
A
I
R
O
M
E w
M o a
l
l e
S a r
E h A
N S p
I l u
O e n
c
M a
r
a e
l
3
0L
0egend
S P C
E
L l
D i
L o L o r a
LL Parcel Sediment Cleanup Area S
L a k e
LL Parcel Shallow Soil Cleanup Area
Approximate Location of Fences
LL Parcel Sediment
Tax Parcel Cleanup Area PORT OF
SEATTLE
Notes:
Tax parcel boundaries based on King County PROPERTY
tax parcel data.
Locations of fences were digitized based on
aerial image cited below and Google Earth
Street View.
Aerial image provided by Port of Seattle
and dated March 20, 2011.
Coordinate grid presented in North American LL
Datum 1983 High Accuracy Reference PARCEL
Network. State Plane Coordinate System,
00 00
Washington North Zone, in units of Survey
4, 0 4, 0
Feet. Map Projection = Lambert Conformal 0 100 200
17 17
Conic.
Scale in Feet
Abbreviation:
LL = Lora Lake.
Cleanup Action Plan
Figure 4.2
Lora Lake Apartments Site
Lora Lake Parcel Cleanup Areas
Burien, Washington
I:\GIS\Projects\POS_LLA\MXD\CleanupActionPlan - T1140\Figure 4.2 Lora Lake Parcel Cleanup Areas.mxd
3/20/2015 REVISED DRAFT
$10
Cleanup Level=13 pg/g
Alt 5, 13 pg/g, 100%
$9 Capping in place (Alt 3)
saves: $0.6 million
compared to capping at
the DMCA (Alt 4); and
$8 $2.1 million compared to
Alt 4, 100 pg/g, 96% excavation (Alt 5)
Alt 3, 100 pg/g, 96% Remediation Level=100 pg/g
$7
Cost (Millions)
Alt 2, 1000 pg/g, 88%
$6
$5 Maximum Concentration
Legend
On site = ~21,000 pg/g
Alternative information presented as: Alternative number,
Alt 1, 21,000 pg/g, 0% Excavation Remediation Level, Percent Mass of Dioxins/Furans
Removed
$4
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Percent Dioxins/Furans Mass Removed
Figure 5.1
Cleanup Action Plan
Lora Lake Apartments Parcel Alternative
Lora Lake Apartments Site
Cost vs. Percent Dioxins/Furans Mass
Burien, Washington
Removed
F:\projects\POS-LLA\Task 1140 - CD and CAP Development\Consent Decree\REVISED DRAFT CD\Exhibit B - Cleanup Action Plan\Figures\Fig 5.1_Dioxin Mass Removed vs. Cost of Implementation for Alternatives_112514.docx REVISED DRAFT
120
Legend
110
100
Mean
90
80
Notes: *Seattle
Dioxins/Furans
TEQ data from
Ecology 2011.
70 **Data has lognormal
distribution.
60
TEQ Concentration (pg/g) /Furans 50
Dioxins 40
30
20 19.0
16.6
10 8.2
0
Seattle* Lora Lake Apartments Lora Lake Parcel
Parcel
Figure 5.2
Cleanup Action Plan Lora Lake Apartments Parcel and
Lora Lake Parcel Soil Dioxins/Furans
Lora Lake Apartments Site
TEQ Concentrations to Remain On-
Burien, Washington site Compared to Dioxins/Furans TEQ
Concentrations in Seattle Urban Soil
REVISED DRAFT
A A' C C'
310 310 310 310
Lora Lake Apartments Parcel
Lora Lake Apartments
Parcel Fence Lora Lake Apartments
Parcel Fence
DMCA 1
100 Year Flood Plain
) Wildlife Barrier E ) E
4,5
10
le le
300 300 va 10 ti o n X )
300 300
ti o va n F n i ti o ra ti o n X n i ee ge ra ee n F (Vt Ex ag ge ag (Vt ic er t Wildlife Barrier
ical
al Ex
Slope Armoring er t ic Exal er t
290 290 290 290
(V ic al t
for Flood Protection
er t EK Ex ge ag ee ag t (V ra n F RE ge ra
Cap in Place or
ee
Excavate Consolidated Soil
n X ti o R C n F ti o n i LE ti o
n i
Consolidate at n X 10 va ti o DMCA, Backfill
E le va 280 280 280 MI L 280 10
E le ) Excavate, Dispose at
Landfill, Backfill
270 270 270 270
Lora Lake
B Parcel Fence B'
e s n l ri a S . Lora Lake Parcel
M oi Me mo Dr .
Des Notes: 1. Approximately 1000 sq. ft (0.7%) of the
290 Excavate, Consolidate 290
at DMCA, Backfill DMCA along its southern boundary lies within
A the 100-year flood-plain. Prior to consolidation,
EK
)
RE C the boundary of the 100-year flood-plain will
be surveyed, and no material will be
10
R C
Wildlife Barrier consolidated in this area.
(for areas where contaminated sediments A B
' LE
are shallower than the 6-ft Conditional E 2.The depth of the biologically active zone n X
280 Point of Compliance line) 280 le MI L (6 ft below ground surface) is established as
ra ti o va
C the conditional point of compliance protective
ge
Wetland Planting Top Soil '
EK ti o
of ecological receptors. This is consistent with.
RE n i
WAC 173-340-7490(4)(a) and with the
ag Ex n F
ical
existence of institutional controls to prevent
R C B
'
ee excavation of deeper soil in the areas per the t
(V er t (V
t
LE RIFS. er t
ee
270 MI L 270 ic
n F
3. Green shading of soils and sediment indicates
Existing Storm Drain al
n i
material contaminated with dioxins/furans.
Outfall Location Darker green shading indicates higher Ex )
Wetland Fill
ti o
ag
concentrations of dioxins/furans.
va
ge
le
ra
Existing Rock Berm NOT TO SCALE
E n X ti o
260 260 10
Sediment Cap
Cross Section Locations
6-foot Conditional
Point of Compliance 0 100 200
(The soil biologically Contaminated
2
active zone ). Sediment Cross Sections Scale i Feet
250 250
DEPARTMENT OF
Cleanup Action Plan Figure 6.1
ECOLOGY Lora Lake Apartments Site
Conceptual Remedy Cross Section
State of Washington Burien, Washington
REVISED DRAFT
Appendix A
SEPA Documents
Withdrawal of Mitigated Determination of Nonsignificance
Issued August 28, 2013
Mitigated Determination of Nonsignificance
Dated April 14, 2015
SEPA Checklist
Dated April 7, 2015
NOTICE OF WITHDRAWAL OF
MITIGATED DETERMINATION OF NONSIGNIFICANCE
Name of Proposal: Lora Lake Apartments Site Cleanup Plan
Environmental Document Being Withdrawn: Mitigated Determination ofNonsignicance
for Lora Lake Apartments Site Cleanup Plan issued August 28, 2013.
This MDNS is being withdrawn and will be re-issued with a revised cleanup action plan, SEPA
checklist, and mitigation measures.
Description of Proposal: This proposal is for the cleanup of the Lora Lake Apartments Site as
required by the Model Toxics Control Act Cleanup Regulation, Chapter 173-340 WAC. An area
of shallow soil with dioxins/furans contamination slightly exceeding the dioxins/furans cleanup
level is located within a habitat mitigation area managed according to a Natural Resources
Management Plan. Environmental covenants on the area require that any activity in the
Mitigation Area shall use methods that minimize damage to the Mitigation Area, and that
following the activity the Mitigation Area will be restored to the condition contemplated in the
Corps/Ecology-approved Natural Resource Mitigation Plan.
The original proposal to address shallow soil with dioxins/furans contamination slightly
exceeding the dioxins/furans cleanup level was to leave it in place, consistent with Ecology's
expectation that cleanup actions do not result in a signicantly greater overall threat to human
health and the environment than other alternatives. Comments received during the public
comment period indicated that excavation of the slightly contaminated soil was preferred.
The proposed cleanup action has been revised to excavate shallow soil to bring shallow soil
dioxins/furans concentrations into compliance with dioxins/furans cleanup levels.
Location of Proposal: 15001 Des Moines Memorial Drive, Burien Washington. The proposed
cleanup action is located immediately northwest of the Third Runway at the SeattleTacoma
International Airport.
Lead Agency: Washington State Department of Ecology
Responsible Official: Robert W. Wairen
Position/Title: Section Manager, Toxics Cleanup Program, Northwest Regional Ofce
Address: Washington State Dept. of Ecology, 3190 160th Avenue SE, Bellevue, WA 98008
Phone: 425649-7054 w
Signaturez/ - '
Date: '2" (i7 ' [5/
Robert W. Wairen
STATE EN V IRONMENTAL POLICY ACT (SEPA)
MITIGATED DETERMINATION OF NONSIGNIFICANCE (MDNS)
FOR THE LORA LAKE APARTMENTS SITE CLEANUP PLAN
Description of Proposal: Lora Lake Apartments Site Cleanup Plan
The proposed cleanup action at the Lora Lake Apartments site is described in the SEPA
Environmental Checklist. The proposed cleanup action plan was prepared by the Department of
Ecology (Ecology) acting in accordance with the Model Toxics Control Act, Chapter 70.105D
RCW, and the regulation promulgated there under at Chapter 173-340 WAC, the Model Toxics
Control Act Cleanup Regulation. The proposed cleanup action will be implemented by the Port
of Seattle.
The proposed cleanup action will involve excavation of more highly contaminated soil, capping
of less highly contaminated soil, and rehabilitation of Lora Lake, which occupies a former peat
mine, by converting it to a scrub-shrub wetland habitat consistent with the surrounding aquatic
wetland mitigation area. The cleanup will be conducted under a Consent Decree between the
Washington State Department of Ecology and the Port of Seattle.
Proponent: Port of Seattle
Location of proposal, including street address, if any: 15001 Des Moines Memorial Drive,
Burien, Washington. The proposed cleanup action is located immediately northwest of the Third
Runway at the Seattle-Tacoma International Airport.
The Proposal consists of three areas: (1) Lora Lake Apartments Parcel (LL Apartments Parcel),
(2) Lora Lake Parcel (LL Parcel), and (3) 1982 Dredged Material Containment Area (DMCA).
The Proposal straddles the boundary between the Cities of Burien and SeaTac, Washington.
The LL Apartments Parcel occupies approximately 8.3 acres of currently vacant land in the City
of Burien that is bounded to the north by State Route 518 (SR 518), to the east and southeast by
Des Moines Memorial Drive, to the West by 8th Avenue South, and to the south by an open
area.
The LL Parcel is located to the southeast of the LL Apartments Parcel, on the east side of Des
Moines Memorial Drive. The LL Parcel consists of approximately 7.1 acres of land, including
the approximately 3-acre Lora Lake and a Port-constructed aquatic habitat mitigation
area, and to
the west and northwest by Des Moines Memorial Drive. The DMCA is located adjacent to the
LL Parcel, to the northeast, on Port property. The DMCA is located within the secured airport
area, within security fencing. The DMCA has an area of approximately 2.75 acres. The eastern
half of the DMCA is an approximately 1.5-acre vegetated area covered by a mixture of
grasses
and invasive and pioneering plant species. The remaining approximately 1.25
acres of land is
the location of the Approach Lighting System for SeaTac International Airport.
Description of mitigation: The Lora Lake Parcel lies within a Port-constructed aquatic habitat
mitigation area. Restrictive covenants on this area require that following any activity in the
mitigation area, the Port shall restore the mitigation area to the conditions contemplated in the
Natural Resource Mitigation (NRMP) Plan governing the area. This Plan was approved by the
US. Army Corps of Engineers and Ecology.
A small area of contaminated soil on the western margin of the Lora Lake Parcel will be
excavated and backlled. Lora Lake Will be lled to restore it to a scrubshrub wetland.
The environmental damage caused by the excavation will be mitigated by replanting the areas in
accordance with the NRMP. The environmental damage caused by lling Lora Lake will be
mitigated by grading and planting the area with wetland terrestrial species consistent with the
NRMP for the area. The wetland will be designed so that it does not adversely impact the
functioning of the Port's mitigation areas. This includes not adversely impacting ood
frequencies in Miller Creek. The wetland design and construction will also comply with all
applicable permits and resource agency requirements. All disturbed areas will be restored to the
conditions contemplated in the NRMP which governs the area.
Lead Agency: Washington State Department of Ecology
The lead agency has determined that this proposal, with mitigation described, will not have a
probable signicant adverse impact on the environment. An environmental impact statement
(EIS) is not required under RCW 43.21C.030(2)(c). This decision was made after review of a
completed environmental checklist and other information on le with the lead agency. This
information is available to the public on request. The most relevant documents may be accessed
from Ecology's Lora Lake Apartments website,
http_s://f01tress.wa.gov/ecy/gsp/Sitepage.aspx?csid=2008 (click on View Electronic Documents).
I] There is no comment period for this DNS.
[:1 This DNS is issued after using the optional DNS process in WAC 19711-355. There is
no further comment period on the DNS
This MDNS is issued under WAC 1971 1340 and WAC 19711350. The lead agency
will not act on this proposal for 30 days from the date below. Comments must be
submitted by 30 days from the date below.
Responsible ofcial: Robert W. Warren
Position/Title: Section Manager, Toxics Cleanup Program, Northwest Regional Ofce
Address: Washington State Dept. of Ecology, 3190 160th Avenue SE, Bellevue, WA 98008
Phone: 425-6497054 ._
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There is no agency appeal.
SEPA ENVIRONMENTAL CHECKLIST
UPDATED 2014
Purpose of checklist:
Governmental agencies use this checklist to help determine whether the environmental impacts of your
proposal are significant. This information is also helpful to determine if available avoidance, minimization
or compensatory mitigation measures will address the probable significant impacts or if an environmental
impact statement will be prepared to further analyze the proposal.
Instructions for applicants: [help]
This environmental checklist asks you to describe some basic information about your proposal. Please
answer each question accurately and carefully, to the best of your knowledge. You may need to consult
with an agency specialist or private consultant for some questions. You may use "not applicable" or "does
not apply" only when you can explain why it does not apply and not when the answer is unknown. You may
also attach or incorporate by reference additional studies reports. Complete and accurate answers to these
questions often avoid delays with the SEPA process as well as later in the decision-making process.
The checklist questions apply to all parts of your proposal, even if you plan to do them over a period of time
or on different parcels of land. Attach any additional information that will help describe your proposal or its
environmental effects. The agency to which you submit this checklist may ask you to explain your answers
or provide additional information reasonably related to determining if there may be significant adverse
impact.
Instructions for Lead Agencies:
Please adjust the format of this template as needed. Additional information may be necessary to evaluate
the existing environment, all interrelated aspects of the proposal and an analysis of adverse impacts. The
checklist is considered the first but not necessarily the only source of information needed to make an
adequate threshold determination. Once a threshold determination is made, the lead agency is responsible
for the completeness and accuracy of the checklist and other supporting documents.
Use of checklist for nonproject proposals: [help]
For nonproject proposals (such as ordinances, regulations, plans and programs), complete the applicable
parts of sections A and B plus the SUPPLEMENTAL SHEET FOR NONPROJECT ACTIONS (part D). Please
completely answer all questions that apply and note that the words "project," "applicant," and "property or
site" should be read as "proposal," "proponent," and "affected geographic area," respectively. The lead
agency may exclude (for non-projects) questions in Part B - Environmental Elements that do not contribute
meaningfully to the analysis of the proposal.
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 1 of 26
The Port of Seattle has completed an environmental analysis, including review of pertinent
and available environmental information and preparation of an Environmental Checklist
for the proposed project. This environmental checklist provides specific analysis and
proposed mitigation for the Lora Lake Apartments Site Remedial Action.
A. Background
1. Name of proposed project, if applicable
Lora Lake Apartments Site Remedial Action
2. Name of applicant:
Port of Seattle
3. Address and phone number of applicant and contact person:
Port of Seattle
Aviation/Environmental
PO Box 68727
Seattle, WA 98168
Phone: (206) 787-4918
Contact: Don Robbins
SEPA Checklist prepared by:
Floyd|Snider
601 Union Street, Suite 600
Seattle, WA 98106
Contact: Megan McCullough, Project Engineer
Phone: (206) 292-2078
4. Date checklist prepared:
March 2015
5. Agency requesting checklist:
Washington State Department of Ecology
6. Proposed timing or schedule (including phasing, if applicable):
The site cleanup is expected to occur in a phased approach, with remedial actions
conducted at the Lora Lake Apartments Site (LL Apartments Parcel) and Dredged Material
Containment Area (DMCA) in 2017 and remedial actions conducted at the Lora Lake
Parcel (LL Parcel) in 2017 or 2018.
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 2 of 26
7. Do you have any plans for future additions, expansion, or further activity related
to or connected with this proposal? If yes, explain.
Following completion of remedial actions at the LL Apartments Parcel, the property is
anticipated to be redeveloped into a commercial/light-industrial airport-compatible use
facility. Future site development at the LL Apartments Parcel is not associated with this
cleanup action, and will be conducted under a separate process by the Port and future
owners or tenants. However, any future work will comply with environmental covenants
placed on the property as part of this cleanup action.
Restrictive covenants and local zoning designations prohibit any future development on
the LL Parcel, which will be maintained in perpetuity as a protected wetland aquatic habitat
area.
Federal Aviation Administration (FAA) restrictions prohibit any future development on the
DMCA, which will be maintained as a FAA-defined Runway Protection Zone (RPZ)-
Extended Object Free Area as long as Seattle-Tacoma International Airport (STIA) is an
operating airport. The Port's planned future use of the DMCA is for airport-compatible uses
such as equipment storage and temporary construction laydown that comply with the FAA
RPZ restrictions.
8. List any environmental information you know about that has been prepared, or
will be prepared, directly related to this proposal.
The following documents have been prepared in support of this project, and are available
on the Department of Ecology's project document repository
(https://fortress.wa.gov/ecy/gsp/CleanupSiteDocuments.aspx?csid=2008):
Lora Lake Apartments Agreed Order No. DE6703
Summary Report 2008 Investigations and Data Gap Evaluation, Lora Lakes
Apartments, AECOM, September 2009
Final Remedial Investigation/Feasibility Study, F|S, January 16, 2015
Revised Draft Cleanup Action Plan, F|S, January 2015
These documents also support the project and are available from the Port of Seattle:
Natural Resource Mitigation Plan (NRMP), Seattle-Tacoma International
Airport, Master Plan Update Improvements, Parametrix, 2001
Sea-Tac International Airport Master Plan Archaeological Assessment, King
County, Washington. Report on file at the Department of Archaeology and
Historic Preservation, Olympia, Washington, Iversen, David R., Leonard A.
Forsman, Dennis E. Lewarch, and Lynn L. Larson, 2000.
Wetland Mitigation Monitoring Report, Port of Seattle, 2010
9. Do you know whether applications are pending for governmental approvals of
other proposals directly affecting the property covered by your proposal? If yes,
explain. [help]
No.
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 3 of 26
10. List any government approvals or permits that will be needed for your proposal,
if known. [help]
Local Approvals/Permits:
City of Burien Clearing and Grading Permit (Project is exempt from the procedural
requirements, but must comply with the substantive requirements of this law.
WAC 173-340-710)
City of SeaTac Clearing and Grading Permit (Project is exempt from the
procedural requirements, but must comply with the substantive requirements
of this law. WAC 173-340-710)
City of SeaTac Critical Area Review (Project is exempt from the procedural
requirements, but must comply with the substantive requirements of this law.
WAC 173-340-710)
King County Industrial Discharge Authorization
Federal Approvals/Permits:
USACE Clean Water Act Section 404 Nationwide Permit No. 38 (Required for the
LL Parcel remedial action)
State Approvals/Permits:
Department of Ecology Approval of Engineering Design Report, Plans and
Specifications, Compliance Monitoring Plan, and Operations and Maintenance
Plan
Department of Ecology SEPA Checklist
Department of Ecology NPDES Construction General Permit
Washington State Department of Fish and Wildlife (WDFW) Hydraulic Project
Approval (Required for the LL Parcel remedial action)
11. Give brief, complete description of your proposal, including the proposed uses
and the size of the project and site. There are several questions later in this
checklist that ask you to describe certain aspects of your proposal. You do not
need to repeat those answers on this page. (Lead agencies may modify this form
to include additional specific information on project description.) [help]
The cleanup action selected by the Washington State Department of Ecology (Ecology)
for the LL Apartments Site will occur in three areas: LL Apartments Parcel, the DMCA,
and the LL Parcel.
The LL Apartments Parcel occupies approximately 8.3 acres of currently vacant land. The
LL Apartments Parcel is covered by asphalt parking areas, concrete building foundations,
and landscaping areas remaining from the previous LL Apartments complex that was
demolished in 2009. The remedy includes excavation and off-site landfill disposal of
19,000 cubic yards (CY) of soil with dioxins/furans toxicity equivalent (TEQ)
concentrations greater than 100 picograms per gram (pg/g). Up to approximately 30,000
CY of additional soil will either by capped or will be excavated and consolidated within the
Site to minimize the need for capping and institutional controls on the LL Apartments
Parcel. The portion of the LL Apartments Parcel not within the RPZ may be sold for
commercial or light industrial redevelopment after construction. It is anticipated that the
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 4 of 26
30,000 CY of material will be contained within the LL Apartments Parcel or consolidated
at the DMCA. Groundwater encountered during excavation, and removed for dewatering
purposes will be collected and treated as needed prior to disposal either at an off-site
facility, or to the sanitary sewer under applicable authorizations.
The existing on-site stormwater conveyance system will be abandoned and relocated in
coordination with remedial actions at the LL Apartments Parcel. The storm drain main line
that carries stormwater from upgradient City of Burien is planned for relocation by the City
in conjunction with the City's stormwater improvements for the Northeast Redevelopment
Area (NERA) plan. NERA is a 135-acre area that is planned for transformation into uses
compatible with airport operations and includes stormwater management facilities. It is
anticipated that this stormwater work will occur prior to remedial actions at the LL
Apartments Parcel. If this work is not conducted, the existing stormwater conveyance
system will be replaced, and will discharge to the constructed wetland at the LL Parcel,
and infiltrate.
The LL Parcel is located to the southeast of the LL Apartments Parcel, across Des Moines
Memorial Drive. The LL Parcel consists of approximately 7.1 acres of land, including the
approximately 3-acre Lora Lake and a STIA constructed wetland aquatic habitat mitigation
area. Areas of contamination in shallow soil on the west side of the LL Parcel will be
excavated. Excavated material will be consolidated at the Dredged Material Containment
Area. It may also be sent off-site for disposal at a licensed disposal facility if that is more
efficient for construction scheduling. The excavation volume will be approximately 2,300
CY, and will extend outside of the security fence to the edge of the paved sidewalk along
Des Moines Memorial Drive. The environmental damage caused by the excavation will be
mitigated by replanting the areas in accordance with the NRMP that covers the area. Lora
Lake sediments will be isolated through open water filling to convert the area to a scrubshrub
wetland. This action will require filling the lake over the entire lake footprint to depths
between approximately 2 to 13 feet, based on existing bathymetry. Following filling, the
former lake area will be graded and planted with wetland terrestrial species consistent with
the Natural Resources Mitigation Plan for the area. The wetland will be designed so that
it does not adversely impact the functioning of the Port's mitigation areas covered by the
NRMP. This includes not adversely impacting flood frequencies in Miller Creek. The
wetland design and construction will also comply with all applicable permits and resource
agency requirements.
The DMCA is located adjacent to the LL Parcel, to the northeast, on Port property. The
DMCA is located within the secured airport security fencing and is monitored and accesscontrolled
by Port security as STIA property. The DMCA is approximately 2.75 acres,
based on review of aerial photographs, and the known site historical operations. The
eastern half of the DMCA is an approximately 1.5-acre vegetated area covered by a
mixture of grasses and invasive and pioneering plant species. The remaining
approximately 1.25 acres of land is the location of the Approach Lighting System for the
STIA 3rd Runway, which was constructed in 2006. This area has been regraded and
covered with gravel and is maintained by the Port to be free of vegetation. Future land
uses at the DMCA will be airport-compatible uses in compliance with the FAA RPZs, such
as temporary construction laydown, or equipment storage. Land use improvements to
allow for this future use will consist of surface improvements (placement of a compacted
gravel or engineered surface).
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 5 of 26
12. Location of the proposal. Give sufficient information for a person to understand
the precise location of your proposed project, including a street address, if any,
and section, township, and range, if known. If a proposal would occur over a
range of area, provide the range or boundaries of the site(s). Provide a legal
description, site plan, vicinity map, and topographic map, if reasonably available.
While you should submit any plans required by the agency, you are not required
to duplicate maps or detailed plans submitted with any permit applications
related to this checklist.
The LL Apartments Site is located at 15001 Des Moines Memorial Drive in Burien,
Washington, near the northwest corner of STIA. The Site straddles the boundary between
the Cities of Burien and SeaTac, Washington. The LL Parcel is located immediately across
Des Moines Memorial Drive to the east, and the DMCA is located to the northeast of the
LL Parcel, both within the City of SeaTac. The Site Township/Range/Section is
23N/04E/20SW. The three site parcels are shown in Figure 2.1 of the Cleanup Action
Plan.
B. Environmental Elements [help]
1. Earth
a. General description of the site [help]
(circle one): Flat, rolling, hilly, steep slopes, mountainous,
other: flat surfaces at different elevations separated by steep slopes
The LL Apartments Parcel ground surface gradually slopes to the southeast across the
main portion of the property with steeper slopes located adjacent to Des Moines Memorial
Drive and the Highway 518 embankment. To the southeast of the existing property
boundary, the topography continues to gradually slope to the east towards Lora Lake. A
steep slope bounds Lora Lake to the north and west.
The DMCA is relatively flat, with steeper slopes along the western boundary. Elevation
across the DMCA varies by approximately 6-feet across the area.
Topography at the LL Parcel slopes from the western and northern property boundaries
toward Lora Lake. Elevation drops approximately 18-feet between Des Moines Memorial
Drive and the shore of Lora Lake on the west, and approximately 12-feet from the north
side of the parcel to the north shore of the lake.
b. What is the steepest slope on the site (approximate percent slope)? [help]
The steepest slopes on the Site are found along the eastern boundary of the LL
Apartments Parcel, where there is an approximate 65 percent slope from the property
down to Des Moines Memorial Drive, and on the north and west sides of the Lora Lake
Parcel adjacent to the Lake, where there is an approximate 65 percent slope.
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 6 of 26
c. What general types of soils are found on the site (for example, clay, sand, gravel,
peat, muck)? If you know the classification of agricultural soils, specify them and
note any agricultural land of long-term commercial significance and whether the
proposal results in removing any of these soils. [help]
Subsurface geology at the LL Apartments Parcel consists of a discontinuous fill layer that
overlays glacial recessional outwash deposits. At the bottom of the recessional outwash
deposits a silt unit about 10 feet thick was encountered in the eastern portion of the LL
Apartments Parcel.
The fill unit in the vicinity of the LL Apartments Parcel is observed to have a variable
thickness of up to 15 feet, but is absent in the northern portion of the property. The fill is
composed of medium dense to dense, fine to coarse grained sand with rounded gravel.
The underlying native glacial recessional outwash deposits are variable in thickness, but
can be as much as 45 feet thick in the vicinity of the LL Apartments Parcel. The recessional
outwash deposits are characterized as dense to very dense, fine to coarse grained sand,
with gravels up to 2 inches in diameter and occasional silt lenses. There is a stiff to very
stiff clayey silt unit found near the bottom of the recessional outwash deposits (about 10
feet thick), which is likely indicative of a transition into the glacial till deposits. The till
deposits typically consist of very dense silty, gravelly sand. The silt unit and the underlying
till deposits together provide a confining unit (aquitard) beneath the eastern portion of the
LL Apartments Parcel.
To the southeast of the LL Apartments Parcel, the LL Parcel is also underlain by
recessional outwash deposits, which are exposed at the surface. Beneath the recessional
outwash deposits, it is inferred, based on boring data collected during Site investigations,
that the till deposits are also present and create a perched layer on which Lora Lake and
the surrounding wetlands are formed. Lora Lake was formed by peat mining activities, so
the presence of peat in the subsurface is also expected, although only one sediment core
advanced in Lora Lake encountered peat material.
The project does not result in the removal of soil from agricultural land.
d. Are there surface indications or history of unstable soils in the immediate
vicinity? If so, describe. [help]
There are no known surface indications or history of unstable soils within the project area.
e. Describe the purpose, type, total area, and approximate quantities and total
affected area of any filling, excavation, and grading proposed. Indicate source of
fill. [help]
Approximately 19,000 CY of soil will be excavated and disposed of off-site at an
appropriate licensed disposal facility from the LL Apartments Parcel. An additional
approximate 30,000 CY of soil from the LL Apartments Parcel will either be capped on the
LL Apartments Parcel or excavated and consolidated at the DMCA. The excavation will
be backfilled and compacted with material from an Ecology-approved fill source, then
capped to provide a barrier to wildlife exposure. Excavation at the LL Apartments Parcel
covers an area approximately 6 acres.
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 7 of 26
Approximately 2,300 CY will be excavated from the LL Parcel and consolidated at the
DMCA. It may also be sent off-site for disposal at a licensed disposal facility if that is more
efficient for construction scheduling. The excavation will be backfilled and compacted to
existing grade with material from an Ecology-approved fill source that meets the
specifications for fill, included in the NRMP for the mitigation area. Excavation at the LL
Parcel will cover an area of approximately 0.2 acres.
Consolidation of soil at the DMCA could include excavation of material from the LL
Apartments Parcel and LL Parcel. Material would be transported across the street to the
DMCA, where the material will be placed, graded and compacted, and surfaced with
compacted gravel, asphalt, or an equivalent engineered surface that would provide a
barrier to wildlife. Material may be placed over an area of approximately 2.75 acres. This
consolidation may be conducted to reduce the footprint of the Site where contaminants in
soil exceed the Site cleanup level. All excavated areas will be graded and backfilled as
necessary to stabilize the Site for future redevelopment.
Open water filling of Lora Lake is described below in Section 3.
f. Could erosion occur as a result of clearing, construction, or use? If so, generally
describe. [help]
Erosion control measures will be installed prior to start of any ground-disturbing work at
the Site. Erosion and sediment controls will be utilized throughout the work to mitigate
potential erosion during excavation and grading. Following completion of the work, the site
will be stabilized to prevent erosion while the Site awaits redevelopment.
g. About what percent of the site will be covered with impervious surfaces after
project construction (for example, asphalt or buildings)? [help]
Impervious surfaces (asphalt, concrete, or compacted gravel) currently cover
approximately 50 percent of the Site. This project involves remedial excavation and
backfilling. At project completion, impervious surfaces will cover the same or less
percentage of the site than existing conditions.
h. Proposed measures to reduce or control erosion, or other impacts to the earth,
if any: [help]
Temporary erosion and sediment controls (TESC), such as silt fences, straw bales or
waddles, etc., will be used during construction to prevent erosion or transport of soil from
the property. Limitations on vehicles and equipment operation on unpaved areas, wheelwashes
, and similar controls will be implemented to control migration of soil from the
project site. Appropriate construction BMPs will be in place for erosion control in all areas
subject to earth disturbance (including clearing, grading, stockpiling, and materials or
equipment storage). Stormwater will also be collected and treated on-site as needed to
comply with applicable permits and regulations. A Storm Water Pollution Prevention Plan
will also be prepared as part of the Engineering Design Report for the project.
Stormwater management required during and following filling of Lora Lake and
consolidation of material at the DMCA will be determined and evaluated in the design
process, including an evaluation of the potential for an increase in temperature of
groundwater, and flows into Miller Creek from the DMCA area. Construction at the LL
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 8 of 26
Parcel and DMCA will comply with applicable stormwater management regulations,
including Ecology's Stormwater Management Manual for Western Washington (2012),
and the airport's individual NPDES permit. Additionally, in 2013 and 2014, the Port
collected hydrogeologic data from the Lora Lake Parcel, DMCA groundwater wells, and
Miller Creek to evaluate hydrogeologic conditions and determine the design controls
required to ensure no negative impact to Miller Creek from implementation of the Lora
Lake and DMCA remedies.
2. Air
a. What types of emissions to the air would result from the proposal during
construction, operation, and maintenance when the project is completed? If any,
generally describe and give approximate quantities if known. [help]
Operation of construction equipment will result in exhaust emissions within the project
vicinity during construction only. Dust control measures such as wetting exposed soil will
be implemented during construction, as necessary, to protect workers and the public. No
visible dust will be allowed. Dust monitoring will be conducted at appropriate locations
upwind, within and at the periphery of the Site, to assess the effectiveness of dust control
measures. Additional dust control measures will be implemented as necessary.
b. Are there any off-site sources of emissions or odor that may affect your
proposal? If so, generally describe. [help]
There are no known off-site sources of emissions or odor that may affect the proposal.
c. Proposed measures to reduce or control emissions or other impacts to air, if any:
[help]
During construction, dust suppression BMPs will be implemented, including: watering of
exposed soil surfaces, cleaning of construction vehicles to prevent track-out, and street
cleaning, as may be necessary.
3. Water
a. Surface Water: [help]
1) Is there any surface water body on or in the immediate vicinity of the site
(including year-round and seasonal streams, saltwater, lakes, ponds,
wetlands)? If yes, describe type and provide names. If appropriate, state what
stream or river it flows into. [help]
Yes, Lora Lake is located in the Miller Creek watershed and receives stormwater
runoff from the LL Apartments Parcel, City of Burien residential and commercial
drainage areas upgradient of the LL Apartments Parcel, and surrounding
roadways downgradient of the LL Apartments Parcel (e.g., Des Moines Memorial
Drive, SR 518 interchange, City of SeaTac) through a single outfall located near
the northwestern edge of the lake and via non-point source overland flow from the
LL Parcel. Water was also observed entering Lora Lake from the nearby wetlands
to the south, indicating surface water connectivity between the wetlands and lake.
Water from a drainage channel flowing into Lora Lake in the southwest corner of
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 9 of 26
the lake has also been observed. An overflow discharge culvert and overflow berm
is present at the southeast end of the lake. Seasonally, when Lora Lake surface
water levels are elevated, lake water discharges to Miller Creek through the
discharge culvert and by overtopping the overflow berm. When Miller Creek
surface water elevations are elevated (i.e., during periods of heavy rainfall), Miller
Creek surface water discharges to Lora Lake via the same culvert and overflow
berm.
2) Will the project require any work over, in, or adjacent to (within 200 feet) the
described waters? If yes, please describe and attach available plans. [help]
Open water filling of Lora Lake will occur on the LL Parcel to rehabilitate the
wetland and isolate the contaminated sediments beneath clean backfill. Following
filling of the lake, the area will be graded and planted to establish a scrub-shrub
wetland consistent with the surrounding aquatic wetland mitigation area. Figure
4.2 of the Cleanup Action Plan shows the area of Lora Lake to be filled, and the
surrounding wetland mitigation area.
Excavation of shallow soils located approximately 150 feet west of Lora Lake will
occur on the LL Parcel to remove soil contaminated with dioxins/furans TEQ
concentrations greater than 5.2 pg/g. Following excavation, the area will be
backfilled and replanted in accordance with the NRMP that covers the area. Figure
4.2 of the Cleanup Action Plan shows the area of the LL Parcel to be excavated.
3) Estimate the amount of fill and dredge material that would be placed in or
removed from surface water or wetlands and indicate the area of the site that
would be affected. Indicate the source of fill material. [help]
Filling of Lora Lake would consist of the placement of approximately 39,000 CY of
fill material over the open water area of Lora Lake (approximately 120,000 square
feet). Fill depth will range from approximately 2 feet to 13 feet based on existing
bathymetry. This will convert all open water areas of the property to a scrub-shrub
wetland. The source of the fill is not known at this time, but the source will be
provided to Ecology for approval once determined.
4) Will the proposal require surface water withdrawals or diversions? Give
general description, purpose, and approximate quantities if known. [help]
Stormwater from the storm drain traversing the Lora Lake Apartments Site that
enters Lora Lake in the northwest corner of the lake, as described above in 3(a)(1),
is expected to be diverted to a new infiltration facility by the City of Burien off of the
LL Apartments Site. This work is expected to be completed prior to start of
remediation work. After this stormwater work is completed, there will not be surface
water requiring diversion.
If the City of Burien redirects the upstream stormwater down 8th Avenue South
following site remedy construction, the stormwater will be temporarily diverted
around the Site during construction to discharge temporarily to Miller Creek or
another area of the Port-managed mitigation area wetlands downgradient of
construction until the City of Burien work is complete. If the City of Burien work is
not conducted, following site remedy construction, the upstream stormwater will
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 10 of 26
be conveyed to the rehabilitated wetland on the LL Parcel and be infiltrated. If the
stormwater continues to traverse the Site, the utility would be lined in a manner
that prohibits groundwater infiltration and penetration of soils into the pipe. There
is a small segment of Des Moines Memorial Drive from which runoff may continue
to drain to the Lora Lake Parcel following construction of this project, or may be
redirected as part of City utility improvements. This will be determined during the
design process for this work, and will comply with all applicable regulations.
On-site stormwater management will be included in the remedial design, and will
comply with all applicable regulations. The quantity of stormwater is unknown, as
it is dependent on the construction season, which has not been determined.
5) Does the proposal lie within a 100-year floodplain? If so, note location on the
site plan. [help]
The Lora Lake open water area to be filled and rehabilitated as wetland, and a
portion of the DMCA along its southern boundary, may be located within the Miller
Creek 100-year floodplain delineated by the King County Shoreline Master
Program. The preliminary 100-year floodplain extents are shown on Figure A.1
(attached). The Miller Creek 100-year floodplain is located in the stream reach
between South 156th Way and South 160th Street, and is relatively confined to
the channel ravine and is approximately 60 to 100 ft wide. In the stream reach
south of South 160th Street, the floodplain is approximately 80 to 150 ft wide in the
upper reaches. However, farther downstream, it widens to approximately 200 to
250 ft. Urbanization and agriculture have significantly altered the floodplains
associated with Miller Creek. The 100-year floodplain in the vicinity of the Vacca
Farm Site is several acres in size. The wetland area and poor drainage that existed
prior to agricultural drainage activities are evident from the 100-year floodplain
estimated by the Federal Emergency Management Agency (FEMA).
The approximate 100-year flood elevations, vary from 266 ft at the Miller Creek
detention facility outlet to approximately 265 ft at the downstream end of the Vacca
Farm site. A floodway has also been delineated and mapped in a portion of the
floodplain (Figure A.1).
Prior to construction at the LL Parcel and DMCA, a survey will be conducted to
delineate the location of the 100-year floodplain based on elevation. Soil with
dioxins/furans concentrations between 13 and 100 pg/g TEQ will not be
consolidated within the portion of the DMCA that lies within the 100-year floodplain.
The consolidation area will be armored to protect against erosion at the 100-year
floodplain boundary. Stormwater at the DMCA will be managed as described
above in Section B(1)(h).
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 11 of 26
6) Does the proposal involve any discharges of waste materials to surface
waters? If so, describe the type of waste and anticipated volume of discharge.
[help]
Temporary silt control and BMPs will be used during construction to ensure that fill
operations do not adversely impact downstream water quality. For locations with
soft, unconsolidated sediments, lake filling will likely be completed in two phases.
The first layers of sand would be placed in a manner to minimize
disruption/resuspension and gradually strengthen the underlying sediments. The
remainder of the fill will then be placed with a more efficient and more cost-effective
methodology. Following the placement of fill material, topsoil would be placed, and
final grading conducted on the converted surface for wetland creation and
vegetation plantings.
b. Ground Water:
1) Will groundwater be withdrawn from a well for drinking water or other
purposes? If so, give a general description of the well, proposed uses and
approximate quantities withdrawn from the well. Will water be discharged to
groundwater? Give general description, purpose, and approximate quantities
if known. [help]
Groundwater remediation will occur through soil source removal. Because soil
remedial actions include excavation and consolidation of deep soil contamination,
soil located below the water table will be removed during construction only.
Dewatering will be required to manage groundwater in the excavation during soil
excavation. Dewatered groundwater during subsurface excavation (an
approximate less than 1 month period), will be contained on-site until tested or
treated as needed to remove solids and chemical contaminants to comply with
discharge requirements. Water will then be discharged to the sanitary sewer under
a permit approval, or hauled off-site for disposal.
Groundwater will be withdrawn from wells on the site for laboratory analytical
testing as part of long-term compliance monitoring. Water will be withdrawn from
the shallow aquifer four times per year from multiple 2-inch PVC wells installed on
the site for testing. The volume of water to be withdrawn is approximately 2 gallons
per well. Water will not be withdrawn for drinking water purposes.
2) Describe waste material that will be discharged into the ground from septic
tanks or other sources, if any (for example: Domestic sewage; industrial,
containing the following chemicals. . . ; agricultural; etc.). Describe the
general size of the system, the number of such systems, the number of
houses to be served (if applicable), or the number of animals or humans the
system(s) are expected to serve. [help]
Waste materials will not be discharged into the ground from a septic system or
other source.
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 12 of 26
c. Water runoff (including stormwater):
1) Describe the source of runoff (including storm water) and method of
collection and disposal, if any (include quantities, if known). Where will this
water flow? Will this water flow into other waters? If so, describe. [help]
Stormwater runoff is currently collected onsite by an existing catch basin
conveyance system connected to the storm water mainline crossing the Site.
During construction, stormwater runoff that has not been in contact with
contaminated soil will be managed as general construction stormwater.
Stormwater that has come in contact with contaminated soil will be collected,
treated as necessary, and either discharged to the sanitary sewer or hauled offsite
for disposal. Following completion of construction, on-site stormwater will be
collected and managed in accordance with applicable regulations. The stormwater
collection system will be determined during design and in coordination with
redevelopment plans, as appropriate.
2) Could waste materials enter ground or surface waters? If so, generally
describe. [help]
The property is a cleanup site with soils containing concentrations of constituents
of concern greater than Washington State Department of Ecology's MTCA
cleanup levels. These constituents have impacted soils, sediments, and ground
water at the Site. This project is not expected to result in any further impacts to
ground or surface waters, and will improve the environmental quality of the
property and parcels.
3) Does the proposal alter or otherwise affect drainage patterns in the vicinity
of the site? If so, describe.
Drainage patterns will be modified in the vicinity of the project site by other projects
not included in this work. Drainage patterns associated with this work will be
restricted to the project site. Drainage at the LL Apartments Parcel will be
redirected to discharge to an infiltration facility south of the property rather than
discharging into Lora Lake. Drainage at the DMCA will be determined during the
design process. Drainage at the LL Parcel will flow through the constructed
wetland at the property prior to discharge to Miller Creek, rather than flowing to
Lora Lake (which will be filled).
d. Proposed measures to reduce or control surface, ground, and runoff water, and
drainage pattern impacts, if any:
Construction stormwater BMPs, such as silt fencing, geotextiles, stormwater
collection, straw bales or wattles, etc. will be used during construction. Stormwater
management systems to address surface runoff will be included in the design for
areas of the Site where impervious surfaces are constructed, and the design
process will evaluate and address impacts from drainage pattern changes.
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 13 of 26
4. Plants [help]
a. Check the types of vegetation found on the site: [help]
__x__deciduous tree: alder, maple, aspen, other
__x__evergreen tree: fir, cedar, pine, other
__x__shrubs
__x__grass
____pasture
____crop or grain
____Orchards, vineyards or other permanent crops.
__x__wet soil plants: cattail, buttercup, bullrush, skunk cabbage, other
__x__water plants: water lily, eelgrass, milfoil, other
____other types of vegetation
b. What kind and amount of vegetation will be removed or altered? [help]
The majority of the LL Apartments Parcel is covered with paved parking areas and
apartment building foundations. The parcel is vacant and is surrounded by a fence.
Vegetation located on the LL Apartments Parcel is present along the parcel margins, on
median strips and dividers in the parking lots, or are in areas where plants have colonized
breaks in the pavement. The majority of vegetation within these areas will be removed by
construction.
The LL Parcel is currently a constructed wetland aquatic habitat mitigation area, part of
the Miller Creek/Lora Lake/Vacca Farm Wetland and Floodplain Mitigation Area. The LL
Parcel is densely vegetated and contains a mixture of grasses, forbs, emergent wetland
plants, and a canopy of mixed deciduous trees. The Miller Creek/Lora Lake/Vacca Farm
Wetland and Floodplain Mitigation Area was enhanced by the Port to support aquatic,
amphibian, and wetland habitat as part of the mitigation requirements associated with
development of the STIA 3rd Runway (Port of Seattle 2010). The operation and
maintenance requirements for the Miller Creek/Lora Lake/Vacca Farm Wetland and
Floodplain Mitigation Area are described in the NRMP (Parametrix 2001). Soil removal in
the aquatic habitat mitigation area will remove plant communities. The environmental
damage caused by the excavation will be mitigated by replanting the areas at the
completion of construction activities in accordance with the NRMP that covers the
approximately 31,000-square-foot area. It is estimated that another approximately 10,000
square feet of vegetation will be removed for access to the Lake during lake filling
activities, and will be replanted at the completion of construction activities.
The eastern half of the DMCA is currently a vegetated area covered by a mixture of
grasses and invasive and pioneering plant species, while the western half of the DMCA
lies underneath the Approach Lighting System for the STIA 3rd Runway, is covered in
gravel, and is maintained by the Port to be free of vegetation. The DMCA is located outside
of the Miller Creek/Lora Lake/Vacca Farm Wetland and Floodplain Mitigation Area, but
remains subject to the WHMP as it is located within the FAA RPZ-Extended Object Free
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 14 of 26
Area. The full DMCA area will be cleared of vegetation as part of this action (except for
any area located within the 100-year floodplain, as material consolidation will not be
conducted in this area).
c. List threatened and endangered species known to be on or near the site. [help]
No threatened or endangered plant species are known to be on or near the Site.
d. Proposed landscaping, use of native plants, or other measures to preserve or
enhance vegetation on the site, if any: [help]
The LL Apartments Parcel and DMCA will not be landscaped as part of this project.
Landscaping at the LL Parcel will be consistent with the requirements of the NRMP for the
site, which uses native plants.
e. List all noxious weeds and invasive species known to be on or near the site.
LL Apartments Parcel is currently vegetated with ruderal groundcover including grasses,
blackberries, scotch broom, and a mixture of ornamental and native trees; ornamental
plantings located on median strips and dividers in the parking lots; and forbs and grasses
that have opportunistically colonized breaks in the pavement.
The eastern portion of the DMCA is currently covered by a mix of grasses and invasive
and pioneering plant species including scotch broom, alder saplings, Himalayan
blackberry, and butterfly bush.
The LL Parcel is densely vegetated and contains a mixture of grasses, forbs, emergent
wetland plants, and a canopy of mixed deciduous trees.
5. Animals
a. List any birds and other animals which have been observed on or near the site
or are known to be on or near the site. Examples include: [help]
BIRDS: Ducks, geese, grebes, cormorants, herons, coots, plovers, hawks, eagles,
falcons, owls, swifts, hummingbirds, kingfishers, tyrant flycatchers, crows, jays, swallows,
chickadees, nuthatches, wrens, kinglets, thrushes, starlings (introduced), waxwings,
warblers, sparrows, toehees, blackbirds, finches, old world sparrows (introduced),
pigeons, doves, woodpeckers
MAMMALS: moles, mice, voles, muskrat, beaver, squirrels (introduced), bats, rabbits
(introduced), opossum, weasels, skunks, raccoons, coyote, bobcat, deer
REPTILES: snakes, lizards;
AMPHIBIANS: salamanders, ensatinas, frogs
FISH: bass, chum and coho salmon, trout, herring, bullhead trout
OTHER: shellfish, aquatic and terrestrial invertebrates
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 15 of 26
b. List any threatened and endangered species known to be on or near the site.
[help]
A biological assessment was prepared to evaluate impacts on threatened and
endangered species and essential fish habitat associated with The Final Seattle-Tacoma
International Airport Comprehensive Development Plan (POS SEPA No. 07-09) (2009).
This assessment included the area associated with this project and found no significant
impact.
Subsequently, on October 3, 2013, the Streaked Horned Lark was listed as a threatened
species under the US Endangered Species Act. This listed subspecies is in documented
decline in Washington State and is currently only found on a few large open grassland
sites in Washington such as the Olympia Airport and Joint Base Lewis-McCord, coastal
foredunes in southern Washington, and islands in the lower Columbia River. Between May
and July of 2014, the Port conducted three presence and absence surveys. The Streaked
Horned Lark was not detected at Seattle-Tacoma International Airport (Center for Natural
Lands Management, 2014).
c. Is the site part of a migration route? If so, explain. [help]
The airport is within the Pacific Flyway, the primary avian migration route on the Pacific
Coast; migratory birds stop-over during spring and fall migrations, but may not choose to
breed or over-winter on airport property. Year-round or resident birds may migrate short
distances to and from the Site within their local range.
d. Proposed measures to preserve or enhance wildlife, if any: [help]
The LL Parcel is located within a monitored and managed mitigation area, and will
continue to be following project completion. The projects to be completed at the LL
Apartments Parcel and DMCA are not expected to preserve wildlife, and the projects are
not expected to enhance wildlife in the future.
e. List any invasive animal species known to be on or near the site.
BIRDS: European starlings, English house sparrows
MAMMALS: Eastern grey squirrel; Eastern cottontail
REPTILES: none
AMPHIBIANS: American bullfrog
FISH: unknown
OTHER: unknown
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 16 of 26
6. Energy and natural resources
a. What kinds of energy (electric, natural gas, oil, wood stove, solar) will be used to
meet the completed project's energy needs? Describe whether it will be used for
heating, manufacturing, etc. [help]
There are no energy needs for the completed project.
b. Would your project affect the potential use of solar energy by adjacent
properties? If so, generally describe. [help]
No.
c. What kinds of energy conservation features are included in the plans of this
proposal? List other proposed measures to reduce or control energy impacts, if
any: [help]
The proposed project is a short-term construction project, without long term equipment
operation, and there will be negligible energy impacts during remediation activities. Low
fuel consumption equipment will be used where possible, and construction activities will
be conducted during daylight hours to avoid the requirement for sight lighting.
7. Environmental health
a. Are there any environmental health hazards, including exposure to toxic
chemicals, risk of fire and explosion, spill, or hazardous waste, that could occur
as a result of this proposal? If so, describe. [help]
1) Describe any known or possible contamination at the site from present or
past uses.
The property is a cleanup site with soils containing concentrations of contaminants
of concern greater than Washington State Department of Ecology's MTCA
cleanup levels. These contaminants have impacted soil, sediments, and
groundwater at the Site. Project environmental field staff and contractors may
come into contact with the Site soil, sediment, or groundwater. Field staff will be
required to have appropriate health and safety training, be enrolled in a medical
monitoring program, and have current hazardous waste operations and
emergency response training. Protection monitoring during remedy construction
will be conducted to provide protection of human health and the environment
during the construction and operation and maintenance activities required at the
Site. Protection monitoring requirements will be described in Health and Safety
Plans covering the activities both during construction, and during any future
operations and maintenance of the constructed remedy. Any activities conducted
at the Site following remedy implementation that disturb areas where
contamination has been contained on-site will require following an appropriate
Health and Safety Plan, and any environmental covenants placed on the area. The
Health and Safety Plans will include provisions for protecting human health and
the environment beyond the property boundary.
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 17 of 26
2) Describe existing hazardous chemicals/conditions that might affect project
development and design. This includes underground hazardous liquid and
gas transmission pipelines located within the project area and in the vicinity.
This project is an environmental cleanup. Existing hazardous chemicals and
conditions at the Site are well known and documented. Existing site utilities are
also known, and mapped. There are no major utilities located within the project
site that will impact project development or design. At the DMCA, the 3rd Runway
approach lighting system foundations will require soil consolidation to be designed
in a manner that does not impact the structural integrity of the foundations.
3) Describe any toxic or hazardous chemicals that might be stored, used, or
produced during the project's development or construction, or at any time
during the operating life of the project.
During construction, fuels for vehicle operation may be temporarily stored on-site.
Any fuel storage will require secondary containment, and on-site absorbent
materials for use if needed to respond to an accidental release. No other
hazardous or toxic chemicals will be stored or used on-site. No toxic or hazardous
chemicals will be produced at any time during the operating life of the project.
Spill kits will be kept on-site to respond to fuel or hydraulic oil leaks from
construction equipment.
4) Describe special emergency services that might be required.
No special emergency services are expected to be required as a result of
implementing the project. Construction-related accidents or injuries may require
response from local fire, police, air units, or ambulances. The Port maintains its
own police force and firefighting and rescue units that would be called upon for
these types of incidents. The Port also maintains a trained response team
available to respond at all times to any spill or loss of contaminated or hazardous
materials.
5) Proposed measures to reduce or control environmental health hazards, if
any:
Safe work practices and protection monitoring requirements will be described in
worker Health and Safety Plans covering the worker activities both during
construction, and during any future operations and maintenance of the
constructed remedy. The Health and Safety Plans will also include descriptions
of the appropriate Personal Protective Equipment to be used during site activities.
b. Noise
1) What types of noise exist in the area which may affect your project (for
example: traffic, equipment, operation, other)? [help]
The Site is bordered by a freeway, and an airport. Noise associated with roadway
and air traffic at STIA is not expected to affect this project.
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 18 of 26
2) What types and levels of noise would be created by or associated with the
project on a short-term or a long-term basis (for example: traffic,
construction, operation, other)? Indicate what hours noise would come from
the site. [help]
Construction of the proposed project will involve temporary short-term increase
in noise associated with the use of construction equipment and/or heavy truck
traffic. There are no long-term contributions to area noise levels.
3) Proposed measures to reduce or control noise impacts, if any: [help]
Short-term noise from construction activities will be mitigated by the use of Best
Management Practices (BMPs) and adhere to the City of Burien's and the City of
SeaTac's noise ordinances. There are no long-term noise mitigation measures
proposed because the project will not change existing use.
8. Land and shoreline use
a. What is the current use of the site and adjacent properties? Will the proposal
affect current land uses on nearby or adjacent properties? If so, describe. [help]
The LL Apartments Parcel is currently vacant, and fenced. All above-ground structures
including buildings, parking covers, and play areas were removed in 2009. Slab on grade
building foundations, landscaping, curbs, and pavement remain in place.
The majority of the LL Parcel is currently located within security fencing for the STIA, and
is monitored and access-controlled by Port security as STIA property. The Port
constructed a habitat mitigation area, the "Miller Creek/Lora Lake/Vacca Farm Wetland
and Floodplain Mitigation Area," which includes the LL Parcel and other properties located
adjacent to the STIA to the north, east, and south of the LL Parcel following completion of
the STIA 3rd Runway in 2008. Restrictive covenants and local zoning designations
prohibit future development on the LL Parcel to assure permanent use of the property as
a protected wetland aquatic habitat area.
The DMCA is completely located within the security fencing for the STIA, and is monitored
and access-controlled by Port of Seattle security as STIA property. The western portion
of the DMCA is located beneath the 3rd Runway approach lighting system, and is a gravel
surface. The eastern portion of the DMCA is vegetated, and vacant.
The proposed project will not affect land uses on nearby or adjacent properties. Land uses
of the project properties will also remain as airport, and airport-compatible commercial
use.
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 19 of 26
b. Has the project site been used as working farmlands or working forest lands? If
so, describe. How much agricultural or forest land of long-term commercial
significance will be converted to other uses as a result of the proposal, if any? If
resource lands have not been designated, how many acres in farmland or forest
land tax status will be converted to nonfarm or nonforest use? [help]
Through the 1930s, the project area was primarily agricultural, containing family farms,
suburban development, and supporting commercial businesses. The Lora Lake
Apartments property was farmland until the mid-1940s. Since that time, none of the project
property has been used as agricultural or forest land.
1) Will the proposal affect or be affected by surrounding working farm or forest
land normal business operations, such as oversize equipment access, the
application of pesticides, tilling, and harvesting? If so, how:
No.
c. Describe any structures on the site. [help]
There are no structures present within the LL Apartments Parcel or LL Parcel. There are
building foundations remaining at the LL Apartments Parcel.
The third runway approach lighting system crosses the DMCA, and two support structures
are present on the DMCA. These structures are metal truss structures, with a concrete
foundations that are approximately 15-20 feet square.
d. Will any structures be demolished? If so, what? [help]
Removal of the remaining apartments buildings foundations.
e. What is the current zoning classification of the site? [help]
The project area is currently zoned within the boundary of City of Burien as "Airport
Industrial 1" (LL Apartments Parcel) and within the boundary of City of SeaTac as "Aviation
Commercial (AVC)" (LL Parcel) and Aviation Operations (AVO)" (DMCA).
f. What is the current comprehensive plan designation of the site? [help]
Based on the City of Burien and City of SeaTac Comprehensive Plan Future Land Use
Map, the property is designated as Airport Industrial. The City of SeaTac land use map
utilizes a single designation ("Airport") for all properties owned or to be owned by the Port
of Seattle under the Airport Master Plan as updated August 1, 1996.
g. If applicable, what is the current shoreline master program designation of the
site? [help]
The project site is not in a shoreline area.
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 20 of 26
h. Has any part of the site been classified as a critical area by the city or county? If
so, specify. [help]
There are no critical areas within the LL Apartments Parcel or the DMCA; however the LL
Parcel includes Lora Lake and a constructed wetland aquatic habitat mitigation area,
which is part of the Miller Creek/Lora Lake/Vacca Farm Wetland and Floodplain Mitigation
Area.
i. Approximately how many people would reside or work in the completed project?
[help]
No one would reside in the project area. If the site or a portion of the site is redeveloped
for airport compatible commercial or industrial uses there is the potential that people will
work within the completed project area in the future following redevelopment, which is
outside the scope of this project.
j. Approximately how many people would the completed project displace? [help]
There will be no displacement impacts expected as a result of this project.
k. Proposed measures to avoid or reduce displacement impacts, if any: [help]
There will be no persons displaced as a result of this project.
l. Proposed measures to ensure the proposal is compatible with existing and
projected land uses and plans, if any: [help]
No measures are proposed because there will be no changes to existing or projected land
use as a result of this project.
m. Proposed measures to ensure the proposal is compatible with nearby
agricultural and forest lands of long-term commercial significance, if any:
There are no agricultural or forested lands of long-term commercial significance nearby.
9. Housing
a. Approximately how many units would be provided, if any? Indicate whether high,
middle, or low-income housing. [help]
There will be no housing units provided by this project.
b. Approximately how many units, if any, would be eliminated? Indicate whether
high, middle, or low-income housing. [help]
There will be no housing units eliminated by this project.
c. Proposed measures to reduce or control housing impacts, if any: [help]
There will be no housing impacts as a result of this project. Therefore, measures to reduce
or control housing impacts are not proposed.
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 21 of 26
10. Aesthetics
a. What is the tallest height of any proposed structure(s), not including antennas;
what is the principal exterior building material(s) proposed? [help]
No structures will be constructed as part of this project, and all existing structures will be
removed. If soil is consolidated at the DMCA, the land elevation may be raised as much
as 6 to 8 feet.
b. What views in the immediate vicinity would be altered or obstructed? [help]
No views in the immediate vicinity are expected to be altered or obstructed.
c. Proposed measures to reduce or control aesthetic impacts, if any: [help]
There are no measures to reduce or control aesthetic impacts of the proposed project.
11. Light and glare
a. What type of light or glare will the proposal produce? What time of day would it
mainly occur? [help]
Light and glare will not be produced by the project, as no permanent structures or lighting
are included.
b. Could light or glare from the finished project be a safety hazard or interfere with
views? [help]
The finished project will not produce light or glare.
c. What existing off-site sources of light or glare may affect your proposal? [help]
There are no known existing off-site sources of light or glare that may affect the proposal.
d. Proposed measures to reduce or control light and glare impacts, if any: [help]
There are no proposed measures to reduce or control light and glare impacts.
12. Recreation
a. What designated and informal recreational opportunities are in the immediate
vicinity? [help]
There are no designated or informal recreational opportunities in the immediate vicinity of
the project.
b. Would the proposed project displace any existing recreational uses? If so,
describe. [help]
The project will not displace any existing recreational uses.
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 22 of 26
c. Proposed measures to reduce or control impacts on recreation, including
recreation opportunities to be provided by the project or applicant, if any: [help]
There will be no measures to reduce or control impacts on recreation.
13. Historic and cultural preservation
a. Are there any buildings, structures, or sites, located on or near the site that are
over 45 years old listed in or eligible for listing in national, state, or local
preservation registers located on or near the site? If so, specifically describe.
[help]
There are no places or objects listed on, or proposed for, national, state, or local
preservation registers known to be on or next to the site. A search of the Washington State
System for Architectural and Archaeological Records (WISAARD) revealed no
archaeological sites or historic (or potentially historic) structures in the project area. The
nearest archaeological site is 45KI1040, a precontact lithic isolate recovered from a
disturbed context, located about 1,500 feet southwest of the Site. An historic site, 45KI772,
is located just under a mile north of the Site.
There are several historic property inventories that have been completed for a residential
area located to the west of 8th Avenue South between S 150th Street and S 152nd Street.
One historic property inventory (residence) was located at 15060 Des Moines Memorial
Drive, located adjacent to both the LL Apartments Parcel and LL Parcel. While these
resources are considered historic resources (greater than 50 years old), they are not
registered or listed properties.
b. Are there any landmarks, features, or other evidence of Indian or historic use or
occupation? This may include human burials or old cemeteries. Are there any
material evidence, artifacts, or areas of cultural importance on or near the site?
Please list any professional studies conducted at the site to identify such
resources. [help]
There are no structures in or near the project area (other than those associated with the
active airport), so there are no potential impacts to the built environment.
The area was assessed for archaeological potential in 2000 (Iversen et al. 2000:32). The
review concluded that:
Water features in the project area at Miller Creek, Des Moines Creek, Lora Lake, and Lake
Reba have a moderate probability for hunter- fisher-gatherer archaeological deposits as
these areas would have been utilized for procuring fish and potable water. However, Lora
Lake and Lake Reba are not represented on historic maps and may be man-made. If Lora
Lake and Lake Reba are not natural water features, they have a low probability for hunterfisher-gatherer
archaeological deposits.
Historical documentation has confirmed that Lora Lake was created by peat mining
processes in the mid-1930s. Therefore, it is an artificial lake, and has a fairly low potential
for archaeological resources. The project area has been disturbed by farming, peat
mining, industrial activities, and construction of apartments in the northern portion of the
project area.
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 23 of 26
Additionally, review of the following studies identified no known historical, architectural,
and/or cultural resources that were determined eligible to affect historic properties:
Final Environmental Impact Statement for the Proposed Master Plan Update
Development Actions, Seattle-Tacoma International Airport (FAA and Port of
Seattle, 1996);
Final Supplemental Environmental Impact Statement for the Proposed Master
Plan Update Development Actions, Seattle-Tacoma International Airport (FAA
and Port of Seattle, 1997); and
Final Sea-Tac International Airport Comprehensive Development Plan, Sea-Tac
International Airport (FAA and Port of Seattle, 2007).
c. Describe the methods used to assess the potential impacts to cultural and
historic resources on or near the project site. Examples include consultation
with tribes and the department of archeology and historic preservation,
archaeological surveys, historic maps, GIS data, etc. [help]
No impacts to archaeological/cultural resources are anticipated; therefore, no measures
are proposed. An Inadvertent Discovery Plan (IDP) would be prepared to address the
potential discovery of archaeological materials during construction activities.
d. Proposed measures to avoid, minimize, or compensate for loss, changes to, and
disturbance to resources. Please include plans for the above and any permits
that may be required.
Because there are no areas of importance, no measures are necessary to control impacts.
14. Transportation
a. Identify public streets and highways serving the site or affected geographic area
and describe proposed access to the existing street system. Show on site plans,
if any. [help]
The LL Apartments Parcel is accessed by Des Moines Memorial Drive and 8th Avenue
South. The LL Parcel and DMCA are accessed by Des Moines Memorial Drive.
b. Is the site or affected geographic area currently served by public transit? If so,
generally describe. If not, what is the approximate distance to the nearest transit
stop? [help]
The nearest King County Metro bus stops are located 0.5 miles NE of the Site on S. 144th
Street, and 0.2 miles SW of the Site on 8th Ave. S and S. 152nd St.
c. How many additional parking spaces would the completed project or non-project
proposal have? How many would the project or proposal eliminate? [help]
There will be no additional parking spaces created and none will be eliminated by this
project.
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 24 of 26
d. Will the proposal require any new or improvements to existing roads, streets,
pedestrian, bicycle or state transportation facilities, not including driveways? If
so, generally describe (indicate whether public or private). [help]
The proposal will not require any new or improved existing roads, streets, pedestrian,
bicycle, or state transportation facilities.
e. Will the project or proposal use (or occur in the immediate vicinity of) water, rail,
or air transportation? If so, generally describe. [help]
The project is located in the vicinity of the Seattle-Tacoma International Airport. The project
will not use water, rail, or air transportation in the immediate vicinity of the Site.
f. How many vehicular trips per day would be generated by the completed project
or proposal? If known, indicate when peak volumes would occur and what
percentage of the volume would be trucks (such as commercial and
nonpassenger vehicles). What data or transportation models were used to make
these estimates? [help]
There will be no additional vehicular trips generated as a result of the completed project.
Construction will result in a temporary increase in traffic volumes due to haul trucks
importing and removing soil from the Site. During construction, approximately 19,000 CY
of contaminated soil will be transported from the Site by truck and trailer to a licensed
Subtitle D landfill. This will generate approximately 1,000 truck trips during an approximate
6-month construction season.
Approximately 30,000 CY of contaminated soil from the LL Apartments Parcel and
approximately 2,300 CY of contaminated soil from the LL Parcel will be transported by
truck from the LL Apartments Parcel to the DMCA for consolidation. This will generate
approximately 1,600 truck trips from the LL Apartments Parcel to the DMCA during the
same 6-month construction season.
Approximately 46,000 CY of material will be imported to the LL Parcel to fill Lora Lake.
This will generate approximately 2,400 truck trips to the LL Parcel during the approximate
6-month construction season at the LL Parcel.
The scheduling of vehicular trips is unknown, and will consider impacts to the surrounding
neighborhood. These estimated vehicle trips assume a truck and trailer capacity of 20 CY
per truck and trailer, and each truck trip includes to and from the Site.
g. Will the proposal interfere with, affect or be affected by the movement of
agricultural and forest products on roads or streets in the area? If so, generally
describe.
No.
h. Proposed measures to reduce or control transportation impacts, if any: [help]
Use of larger vehicles that transport more material, reducing the total number of trips
required will be implemented as possible. Trips may also be scheduled during the lowest
traffic times of the day to reduce impact on the surrounding roadways.
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 25 of 26
15. Public services
a. Would the project result in an increased need for public services (for example:
fire protection, police protection, public transit, health care, schools, other)? If
so, generally describe. [help]
The project will not require an increased need for public services.
b. Proposed measures to reduce or control direct impacts on public services, if any.
[help]
There are no expected direct impacts on public services.
16. Utilities
a. Circle utilities currently available at the site: |help|
electricity, natural gas, water, refuse service, telephone, sanitary sewer, septic
system, other
All utilities previously serving the Site have been disconnected. Active sanitary sewer lines
are located in the right-ofway.
b. Describe the utilities that are proposed for the project, the utility providing the
service, and the general construction activities on the site or in the immediate
vicinity which might be needed. |help|
Sanitary sewer may be required during the project for discharge of dewatering water, or
collected stormwater. Sanitary service would be provided by the Southwest Suburban
Sewer District, through a connection in the adjacent right-ofway.
C. Signature [HELP]
The above answers are true and complete to the best of my knowledge. I understand that
the lead agency is relying on them to make its decision.
/ "7%
Signature:
Name of signeeM
3 Pa Hl9.
Position and Agency/OrganizationW0"?
Date Submitted:MK,
SEPA Environmental checklist (WAC 197-11-960) May 2014 Page 26 0f 26
Legend
????????????????????
????????????????????
Dredged Material
Containment Area
(DMCA)
SR518
#
Lora Lake Apartments
Parcel
#
Lora Lake
Parcel
??????
?????????????????????????????????????? ? ??? ??? ???
???????????????????????????????????????????
???????????????????????????????????? ?????????????
Port of Seattle ??????????
Lora Lake Apartments Site ??????????????????????
Burien, Washington ??????????
????????????????????????????????????????????????????????????????
????????
Exhibit C
Scope of Work and Schedule
Lora Lake Apartments Site
Exhibit C: Scope of Work and Schedule
Deliverable/Milestone Completion/Due Date
th
Monthly on the 15 of the month beginning after
Progress Reports
effective date of Consent Decree
Cost Estimate for Consent Decree Implementation
60 days after effective date of Consent Decree
(per Consent Decree Section XXI)
Proof of Financial Assurances 60 days following Ecology approval of the Cost
(per Consent Decree Section XXI) Estimate for Consent Decree Implementation
Annual Financial Assurance Report Annually, within 30 days of the anniversary date
(per Consent Decree Section XXI) of Consent Decree
Draft Compliance Monitoring Plan for the LL Apartments Submitted to Ecology within 60 days of effective
Parcel and DMCA date of Consent Decree
Final Compliance Monitoring Plan for the LL Apartments Submitted to Ecology within 30 days following
Parcel and DMCA receipt of Ecology comments
Submitted to Ecology within 120 days of
Final Data from Compliance Monitoring Event
submittal of Final Compliance Monitoring Plan
Submitted to Ecology within 6 months of receipt
Draft 60% LL Apartments Parcel and DMCA Engineering
of final data from the Compliance Monitoring
Design Report (EDR)
Event
Submitted to Ecology within 6 months of Ecology
Draft 100% LL Apartments Parcel and DMCA EDR, Project
review of the Draft 60% LL Apartments Parcel
Plans and Specifications, and O&M Plan
and DMCA EDR
Final 100% LL Apartments Parcel and DMCA EDR, Project Submitted to Ecology within 30 days following
Plans and Specifications, and O&M Plan receipt of Ecology comments
Within 2 years of Ecology approval of the 100%
Completion of LL Apartments Parcel and DMCA Cleanup
LL Apartments Parcel and DMCA Project Plans
Construction
and Specifications
Draft LL Apartments Parcel and DMCA As-Built Report Submitted to Ecology within 90 days of
(includes Environmental Covenants for LL Apartments Parcel completion of LL Apartments Parcel Cleanup
and DMCA) Construction
Final LL Apartments Parcel and DMCA As-Built Report
Submitted to Ecology within 30 days of receipt of
(includes Environmental Covenants for LL Apartments Parcel
Ecology comments on the Draft As-Built Report
and DMCA)
Submit proof of recording of LL Apartments Parcel and Submitted to Ecology within 90 days of Final LL
DMCA Environmental Covenants to Ecology Apartments and DMCA As-Built Report
Groundwater Compliance with Cleanup Levels Achieved Within 5 years of construction completion at the
throughout the Site LL Apartments Parcel and DMCA
Installation of Final Barrier to Wildlife on the LL Apartments Within 4 years of construction completion at the
Parcel LL Apartments Parcel
As-Built Report for Final Barrier to Wildlife on the LL Submitted to Ecology within 90 days of
Apartments Parcel completion of construction
Within 1 year of submittal of the Final 100% LL
Draft 60% LL Parcel EDR
Apartments and DMCA Project Plans and
(includes Compliance Monitoring Plan and O&M Plan)
Specifications
Draft 100% LL Parcel EDR, Project Plans and Specifications, Submitted to Ecology within 6 months of Ecology
Compliance Monitoring Plan, and O&M Plan review of the Draft 60% LL Parcel EDR
Submitted to Ecology within 30 days following
Final 100% LL Parcel EDR, Project Plans and Specifications,
receipt of Ecology comments on Draft 100% LL
Compliance Monitoring Plan, and O&M Plan
Parcel EDR
Within 2 years of Ecology approval of the 100%
Completion of LL Parcel Cleanup Construction
LL Parcel Project Plans and Specifications
Draft LL Parcel As-Built Report (includes Environmental Submitted to Ecology within 90 days of
Covenant for LL Parcel) completion of LL Parcel Cleanup Construction
Final LL Parcel As-Built Report (includes Environmental Submitted to Ecology within 30 days of receipt of
Covenant for LL Parcel) Ecology comments on the Draft As-Built Report
Submit Proof of Recording of LLA Parcel Environmental Submitted to Ecology within 90 days of Final LL
Covenants to Ecology Parcel As-Built Report
At least every 5 years from the effective date of
Periodic Reviews Conducted by Ecology
Consent Decree
Page 1 of 1 Consent Decree Exhibit C
Exhibit D
Applicable or Relevant and Appropriate Requirements
Washington State
Department of Ecology Lora Lake Apartments Site
EXHIBIT D:
Applicable or Relevant and Appropriate Requirements
Approvals/permits required:
Local Approvals/Permits:
King County Industrial Discharge Authorization
Federal Approvals/Permits:
US Army Corps of Engineers (USACE) Clean Water Act Section 404 Nationwide
Permit No. 38
(Required for the Lora Lake (LL) Parcel remedial action)
State Approvals/Permits:
Washington State Department of Ecology (Ecology) State Environmental Policy Act
(SEPA) Checklist
Ecology National Pollutant Discharge Elimination System (NPDES) Construction
General Permit
Washington State Department of Fish and Wildlife (WDFW) Hydraulic Project
Approval (Required for the LL Parcel remedial action)
Page 1 of 1 Consent Decree Exhibit D
Exhibit E
Procedurally Exempt Requirements
Washington State
Department of Ecology Lora Lake Apartments Site
EXHIBIT E:
Procedurally Exempt Requirements
Approvals/Permits Required:
City of Burien Clearing and Grading Permit (Project is exempt from the procedural
requirements, but must comply with the substantive requirements of this law.
WAC 173-340-710)
City of SeaTac Clearing and Grading Permit (Project is exempt from the procedural
requirements, but must comply with the substantive requirements of this law.
WAC 173-340-710)
City of SeaTac Critical Area Review (Project is exempt from the procedural
requirements, but must comply with the substantive requirements of this law.
WAC 173-340-710)
City of SeaTac Haul Permit (Project is exempt from the procedural requirements, but
must comply with the substantive requirements of this law. WAC 173-340-710)
City of SeaTac Maintenance of Traffic Plan (Project is exempt from the procedural
requirements, but must comply with the substantive requirements of this law.
WAC 173-340-710)
Page 1 of 1 Consent Decree Exhibit E
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