Following the accidental release of crumb rubber and field turf into Washington State’s Puyallup River during the in-water construction of a hydroelectric dam project in 2020, civil and criminal lawsuits were filed against the dam owner and operator, Electron Hydro LLC. The lawsuits, brought by the US EPA and the State of Washington, alleged that the release of 4-6 cubic yards of crumb rubber and at least 600 square yards of field turf violated the Clean Water Act, as well as multiple state statutes, and resulted in adverse effects on endangered species. Counsel retained a team from Windward Environmental LLC, now part of Barr, to provide expert testimony in support of both legal cases.
The potential toxicity of crumb rubber in aquatic environments has drawn attention in recent years, particularly in the Pacific Northwest, following the observation of abnormal salmon behavior and salmon mortality during rain events. Urban stormwater runoff, which can carry rubber-tire-related pollutants into waterways, has been linked to high death rates in adult coho salmon. A key chemical of concern is 6PPD, used in tires to prevent cracking. When it reacts with ozone, it forms 6PPD-Q, a compound that can be toxic to juvenile coho salmon.
We used a risk-based biological assessment approach to evaluate whether aquatic species were harmed by the accidental release. Environmental harm was evaluated through an assessment of exposure, concentration, and duration. This assessment included an evaluation of published dose-response data for juvenile coho salmon and 6 PPD-Q, a critical review of an approach for estimating 6 PPD-Q concentrations and potential toxicity, an applicability assessment of toxicity test data, and a close examination of key fate and transport assumptions.
The team produced expert reports detailing the findings, and a team lead was deposed in both the civil and criminal cases. Both lawsuits were successfully settled prior to trial.
