Stormwater

Presentation to the Washington Department of Ecology: 6PPD-Q State of the Science Forum on December 9, 2025 Presented by Laura Baker, Friends of Gualala River, and Timmarie Hamill, CA Urban Streams Alliance-The Stream Team Abstract In 2022, CA Urban Streams Alliance-The Stream Team (The Stream Team) expanded its long-standing watershed monitoring program and began collaborating with Friends of Gualala River …

November 18, 2025For immediate release from Friends of Gualala RiverContact: Laura Baker, 510-684-4572, Lbake66@aol.com With the return of fall storms, Friends of Gualala River in partnership with The Stream Team and other volunteers have launched their second season of testing Gualala stormwater for a potent toxic chemical found in tire grit. The chemical is extremely hazardous to salmonids, especially coho …

Tires treated with 6PPD (which becomes 6PPD-Q) will be with us for a very long time before manufacturers find new alternatives and old tires are removed from the environment. These toxic compounds will continue to affect human health and the health of the environment for decades to come. But in the meantime, here are a few simple steps that you …

May, 2025by Timmarie Hamill, Director, The Stream Team Brief summary: “The results suggest runoff pollution primarily originates from gas stations, parking lots, and Highway 1. For instance, 6PPD-q levels ranged from 71 to 179 ng/L at the Gas Station, Parking Lot, and Footbridge sites, compared to 14 to 28 ng/L at the Above Trinks site. Zinc levels followed a similar …

May, 2025 by Greg Kamman, Professional Geologist & Certified Hydrogeologist Brief Summary: “Because the Project schedule is advancing quickly, we recommend that the Friends of Gualala River convene a meeting with Caltrans and cbec to discuss the findings and conceptual BMP recommendations presented herein. Given The Stream Team’s water quality monitoring expertise and experience in pollutant reduction BMP design, we …

The China Gulch culvert under Highway 1 at the intersection of Old State Highway in Gualala is failing, causing a sinkhole to form at the intersection, and so it needs to be replaced promptly. CalTrans has approved $9.9M for emergency repair, and hopes to complete repairs by the end of November, 2025. China Gulch culvert, west side of Highway 1, …

The China Gulch culvert under Highway 1 at the intersection of Old State Highway in Gualala is failing, causing a sinkhole to form at the intersection, and so it needs to be replaced promptly. CalTrans has approved $9.9M for emergency repair, and hopes to complete repairs by the end of November, 2025. For more information, see: Sinkholes and Salmon May …

Research by King County, WA scientists on how to reduce the toxicity of stormwater runoff is showing promising results and could offer new solutions to the longstanding problem of coho salmon dying from exposure to pollution before they can spawn.

The ever-changing pothole / sinkhole at the convergence of Old State Highway and Highway One is generated by a decaying culvert far underground. If you read the paper two weeks ago or have felt the bump in your car, you know about the sinkhole at the bottom of Old State Highway. The 4ft x 4ft pothole, caused by a failing …

by Laura Baker, Board Member In 2020 FoGR learned of a chemical found in tire grit that pollutes stormwater and kills a number of different aquatic species. It is especially toxic to coho salmon— 40 parts per trillion in a quart of stormwater kills juvenile coho. Information has been pouring out of the State of Washington where the effects of …

Press release by Earthjustice, August 15, 2023 [excerpt] The Institute for Fisheries Resources (IFR) and the Pacific Coast Federation of Fishermen’s Associations (PCFFA) today notified U.S. tire manufacturers of their intent to sue over the use of a chemical called 6PPD in rubber tires because of its devastating impacts on Endangered Species Act (ESA)-protected salmon and steelhead. When 6PPD reacts …

When we think of timber road runoff threats, we habitually think of fine sediment, indirectly affecting coho (and steelhead) by habitat degradation. But this is direct acute mortality by rubber tire chemicals. A new wrinkle on wheeled vehicles operating on rough, abrasive gravel haul roads. – FoGR by Erik Stokstad Science  04 Dec 2020: Vol. 370, Issue 6521, pp. 1145 …