Discovering Toxic Chemicals in Roof Runoff


As part of the Control of Toxic Chemicals in Puget Sound project, Ecology scientists tested rainwater from roofing materials and analyzed it for toxic chemicals.

This first Roofing Materials Assessment provided data to evaluate whether roofing materials are a potential source of toxic chemicals in the Puget Sound basin. Ecology sampled runoff from 14 types of roofing materials during 20 rain events, and analyzed the samples for metals (arsenic, cadmium, copper, lead, and zinc) and organic compounds. Results are explained in the Phase 1 publications and short video below.

When this study concluded, the roofing panels were moved to the Washington Stormwater Center at the Washington State University Puyallup Research and Extension Center in Puyallup, Washington. Here, a second phase of the study continues in 2016.


Discovering Roof Runoff


The 2016 WSC project design calls for chemical analysis of the roof runoff and will test zebrafish, coho salmon juveniles, and a water bug called ceriodaphnia dubia for acute toxicity from the runoff water. The study plan can be found at the link below.

Phase 2 Publications

Quality Assurance Project Plan - Roofing Materials Assessment: Investigation of Toxic Chemicals in Roof Runoff at the Washington Stormwater Center (pdf, leaving Ecology) is the plan for this phase of the study.

Phase 1 Publications

Roofing Materials Assessment: Investigation of Toxic Chemicals in Roof Runoff from Constructed Panels in 2013 and 2014 is the final report from the earlier study.

Focus on Toxics in Roofing: Toxic chemicals in roof runoff is a short focus sheet about the earlier study's results.

The Roofing Task Force, an advisory group of manufacturers, associations, contractors, and other stakeholders, convened to provide input for the design of these studies.

Related Information:


Roofing Materials Assessment: Investigation of Toxic Chemicals in Roof Runoff was the final report for the first round of the study, includes leaching tests.

Quality Assurance Project Plan: Roofing Materials Assessment: Investigation of Toxic Chemicals in Roof Runoff describes the study design for the earlier study.

Focus on: Study evaluates roofing materials for toxic chemicals in runoff is an Ecology focus sheet from the first round of the study.

Control of Toxic Chemicals in Puget Sound is the website for a multi-year, multi-agency effort to protect the Puget Sound from toxics.

Puget Sound Toxics Assessment is the website describing the Assessment of Selected Toxic Chemicals in the Puget Sound Basin, 2007-2011 report.

Focus on Puget Sound: Puget Sound Toxics Assessment is an Ecology Focus sheet.

Focus on Puget Sound: Toxics in Surface Runoff to Puget Sound is an Ecology Focus sheet.

TOXICS STUDIES