Landfill cleanup site — Restorical Research
Sunset Park
13831 18th Ave S, Seatac, King County
Restorical Research
Preliminary Site-Specific Analysis

This property has a documented history as a landfill going back to 1941. Historical insurance policies issued during those prior operations and through 1986 could fund a cleanup — and recover costs already spent.

This property was used as a dumping area for waste oil, bilge oil, oil drums, and old cars beginning in the 1941–1945 period, and was later developed as a Public Works maintenance facility with underground storage tanks constructed around 1968. Oil seepage was observed as early as 1963, and contamination was formally documented in reports from 1979 and a 1983 King County Abandoned Landfill Study. Cleanup under the Voluntary Cleanup Program has been ongoing since at least 1991, including removal of multiple leaking USTs, excavation of impacted soil, groundwater treatment through Oxygen Release Compound applications and waste-oil recovery, removal of residences, installation of a new sanitary line, and planned deed restrictions. That history could support an insurance cost recovery claim against carriers who issued insurance policies 40+ years ago.

Former Use
Former Landfill
Address13831 18th Ave S, Seatac, King County
Historical UseLandfill
Est. Operating Since1941
StatusCleanup Started
Contamination & Investigation
Site Assessment Summary
ContaminantsWaste oil, bilge oil, and petroleum hydrocarbons detected in soil and groundwater
Media ImpactedSoil, Groundwater
Regulatory ProgramMTCA — Voluntary Cleanup Program
Ecology Site #6638

Why Historical Insurance Policies May Be Accessible

Pre-1986 Commercial General Liability (CGL) policies were occurrence-based and did not contain an effective pollution exclusion in Washington. If contamination occurred while those policies were active, those historical insurance carriers may still have a legal obligation to fund the cleanup costs, even if the business closed or the property changed hands.

Contamination at this site traces to dumping and fueling operations that began in the 1940s and continued through facility use predating 1986 — squarely within the era when occurrence-based Commercial General Liability policies carried no effective pollution exclusion in Washington. More than three decades of documented remediation expenditures — tank removals, soil excavation, groundwater treatment, long-term monitoring, and institutional controls still being finalized — represent costs tied to releases that originated under those historical policies. The carriers who issued CGL coverage during that operational window may be obligated both to recover past cleanup costs and to fund the remediation work that remains ahead.

Restorical's role is to locate viable historical policies, determine whether a successful coverage claim is possible, and assist our clients and their legal counsel to obtain insurance coverage. Restorical then manages the claim, including accounting, to ensure the cleanup is funded in a timely manner.

What We Look For

  • Historical insurance policies (pre-1986)
  • Policy numbers, carrier names, and coverage periods
  • Connection between contamination timing and policy period
  • Evidence linking cleanup obligation to insured activity

What We Deliver

  • Historical Coverage Chart
  • Trigger Analysis & Property/Policy Nexus
  • Coverage strategy with recommendations
  • Insurance funding for your remediation
  • Claims Management & Forensic Accounting

The Restorical Proven Process

Task 1 — Research and Analysis
Restorical searches for viable historical insurance policies, researches the site history, analyzes the contamination impacts, and underwrites potential coverage — including a proprietary trigger analysis. At the end of Task 1, we provide a clear yes or no on whether a successful cost recovery is possible, along with a strategy and recommendation specific to your situation, even if you are not the policyholder.
Task 2 — Coverage and Funding
When Task 1 confirms viable coverage, Restorical works with your legal counsel to tender the claim, negotiate and secure insurance coverage. Restorical will manage the ongoing claim process, including accounting to ensure the insurance companies are funding your remediation in a timely manner.

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This analysis is preliminary and based on publicly available records. Restorical Research is not a law firm and does not provide legal advice.