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