Heating Oil Tank cleanup site — Restorical Research
Woodmont Recovery Campus
Des Moines, King County
Restorical Research
Preliminary Site-Specific Analysis

This property has a documented history as a property with a heating oil tank predating 1986. Historical insurance policies issued during those prior operations and through 1986 could fund a cleanup — and recover costs already spent.

This property in Des Moines was formerly a single-family residence with three heating oil underground storage tanks. The first UST was identified by a vent pipe during site reconnaissance in October 2024 and confirmed by ground-penetrating radar survey; two additional tanks were discovered during site development in 2026. Ecology's Technical Assistance letter confirmed that petroleum contamination at the site is attributable to a release from a heating oil UST at the former residence. Groundwater sampling found diesel-range organics in seven of nine wells, with concentrations reaching 160,000 µg/L — more than 300 times the 500 µg/L cleanup level — and remediation under the Voluntary Cleanup Program is underway. That history could support an insurance cost recovery claim against carriers who issued insurance policies 40+ years ago.

Former Use
Former Heating Oil Tank
AddressDes Moines, King County
Historical UseHeating Oil Tank
Est. Operating SincePre-1986
StatusCleanup Started
Contamination & Investigation
Site Assessment Summary
ContaminantsDiesel-range organics (DRO) detected in groundwater at concentrations far exceeding cleanup levels
Media ImpactedSoil, Groundwater
Regulatory ProgramMTCA — Voluntary Cleanup Program
Ecology Site #17375

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.

Residential heating oil USTs in the Pacific Northwest were overwhelmingly installed before 1986, when occurrence-based Commercial General Liability policies were the industry standard. The three tanks at this property remained undiscovered in the ground for decades, consistent with that pre-1986 installation era. With diesel-range organics in groundwater at concentrations hundreds of times above cleanup levels, the remediation costs ahead are substantial — and historical CGL carriers whose policies were in effect when these tanks were installed and operating may be obligated to fund them.

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.