Heating Oil Tank cleanup site — Restorical Research
UW Surface Lot 1
4513-4557 11th Ave NE, Seattle, King County
Restorical Research
Preliminary Site-Specific Analysis

This property has a documented history as a property with a heating oil tank going back to 1905. Historical insurance policies issued during those prior operations and through 1986 could fund a cleanup.

This property at 4513–4557 11th Ave NE was occupied by a row of houses from 1905 until the 1970s, when the structures were demolished and the lot was paved over — leaving heating oil tanks in place beneath the surface. Between 2008 and 2014, cleanup activities removed multiple underground storage tanks, petroleum-contaminated soil, and burned materials; in treated areas, BTEX and PAHs were remediated to below cleanup levels, while remaining impacted soil in other areas was capped with structures and pavement. The site remains enrolled in Washington's Standard Cleanup program, with cleanup not yet complete for all affected areas. That history could support an insurance cost recovery claim against carriers who issued insurance policies 40+ years ago.

Former Use
Former Heating Oil Tank
Address4513-4557 11th Ave NE, Seattle, King County
Historical UseHeating Oil Tank
Est. Operating Since1905
StatusAwaiting Cleanup
Contamination & Investigation
Site Assessment Summary
ContaminantsDiesel and petroleum hydrocarbons (BTEX, PAHs) in soil and groundwater
Media ImpactedSoil, Groundwater
Regulatory ProgramMTCA — Standard Cleanup
Ecology Site #12374

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.

The diesel and petroleum contamination at this site traces directly to residential heating oil tanks that supplied houses occupied from 1905 through the 1970s — a release origin squarely within the pre-1986 era when occurrence-based CGL policies written for residential property owners carried no effective pollution exclusion. Cleanup is not yet closed, and the costs of addressing the remaining petroleum-impacted areas represent forward-looking expenditures those historical policies were written to cover. Property owners and their historical carriers from the residential-use period may retain obligations that have never been presented or recovered.

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.