Gas Station cleanup site — Restorical Research
Unocal 4704
15623 1st Ave S, Burien, King County
Restorical Research
Preliminary Site-Specific Analysis

This property has a documented history as a gasoline service station going back to 1960. Historical insurance policies issued during those prior operations and through 1986 could recover the cleanup costs already paid.

A Unocal gasoline service station was established at this property in 1960, equipped with three steel underground storage tanks, a waste oil tank, and hydraulic hoists. The original USTs were replaced in 1983, and by 1990 elevated concentrations of total petroleum hydrocarbons (TPH-G) and tetrachloroethylene (PCE) had been detected in groundwater above Method A cleanup levels. Groundwater remediation under the Voluntary Cleanup Program included hydrogen release compound (HRC) injections performed in 2000, and the site has since achieved No Further Action status. That history could support an insurance cost recovery claim against carriers who issued insurance policies 40+ years ago.

Former Use
Former Gas Station
Address15623 1st Ave S, Burien, King County
Historical UseGas Station
Est. Operating Since1960
StatusNo Further Action
Contamination & Investigation
Site Assessment Summary
ContaminantsPetroleum hydrocarbons (TPH-G), benzene, and tetrachloroethylene (PCE) detected in groundwater
Media ImpactedSoil, Groundwater
Regulatory ProgramMTCA — Voluntary Cleanup Program
Ecology Site #6349

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.

This gasoline service station operated continuously from 1960 — more than two decades before 1986, when occurrence-based Commercial General Liability policies were still standard and carried no effective pollution exclusion. The petroleum and solvent contamination discovered in groundwater, and the remediation costs incurred to address it — including groundwater treatment and long-term monitoring through to site closure — arose from operations that began squarely within that pre-1986 policy window. Historical carriers who covered the station during its 1960s-through-1980s operational period may still be obligated to respond to those documented cleanup expenditures.

Restorical's role is to locate viable historical policies, determine whether a successful cost recovery claim is possible, and assist our clients and their legal counsel to obtain insurance coverage for costs already incurred. Restorical's forensic accounting team works to re-establish and document past cleanup expenditures, ensuring the strongest possible basis for recovery.

Recovering Costs from an Older Cleanup

If this site reached No Further Action years ago, the original cleanup expenditures may be difficult to reconstruct. Restorical's forensic accounting team specializes in re-establishing and documenting past cleanup costs — even decades later — to build the strongest possible basis for an insurance recovery claim.

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 — Cost Recovery
When Task 1 confirms viable coverage, Restorical works with your legal counsel to tender the claim and negotiate recovery of costs already incurred. Restorical's forensic accounting team re-establishes and documents past cleanup expenditures, managing the claim process to ensure the insurance companies fulfill their obligation 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.