Stormwater facts

The search for why large numbers of spawning coho salmon have been dying in Puget Sound's urban streams goes as far back as the 1980s and culminated this year with the discovery of a previously unidentified chemical related to automobile tires. We offer a detailed timeline for the discovery. 

Environmental engineers and chemists at the University of Washington Tacoma have identified a mysterious compound implicated in the deaths of large numbers of coho salmon in Puget Sound. The chemical is linked with a rubber additive commonly used in tires and is thought to kill more than half of the spawning coho that enter the region's urban streams every year. 

Modern automobile tires are a complex mixture of chemicals, all used together in different ways to give tires their structure and properties, including riding comfort, safety and long life. Chemicals from tire wear particles are now thought to be responsible for the deaths of large numbers of coho salmon returning to spawn in Puget Sound streams. 

Many creeks and waterbodies in Puget Sound may look pristine, but most face serious threats from stormwater pollution. A new study at Soos Creek shows how mud-dwelling bugs, traditional chemistry and digital "heatmaps" can be used to track stormwater impacts and identify the most polluted areas. Scientists and planners hope that this may one day lower the price tag on costly stormwater fixes. 

The Toxics in Fish Implementation Strategy is a recovery plan that will guide funding and activities to reduce the impacts of toxics contaminants on marine fish and the humans that consume them. A final version of the plan was published in May 2021.

Many groups have been formed around the goal of saving salmon, but few people talk about a concerted effort to save microscopic creatures. Whether or not a pro-bug movement catches on, future strategies to save salmon are likely to incorporate ideas for restoring streambound creatures known as benthic invertebrates.

How does one of the West's busiest airports deal with extreme stormwater, and what does that mean for water quality standards in the rest of the state?

Pollution from stormwater has been called one of the greatest threats to Puget Sound. How much will it cost to hold back the rain? A new EPA-funded study says the price could reach billions per year, a figure that dwarfs current state and federal allocations.

Finding a replacement for 6PPD in tires is one major challenge; another is to prevent the highly toxic derivative 6PPD-Q from reaching salmon streams and killing fish.

Research that began in Puget Sound has revealed much about the cellular-level assault on vulnerable salmon and trout, yet the puzzle remains incomplete.

Longfellow Creek near West Seattle's industrial district still draws spawning salmon despite a century of city development and an onslaught of toxic chemicals. A current exhibit by photographer Tom Reese explores this often-overlooked gem of urban nature.

A 2023 report from the Puget Sound Ecosystem Monitoring Program presents an overview of selected recent monitoring and research activities focused on toxic contaminants in the Salish Sea. 

High levels of mercury and other toxic chemicals are showing up in seemingly remote and pristine parts of the Puget Sound watershed, the result of atmospheric deposition. Scientists talk about a “dome” of pollution hanging over urban areas, leading to a never-ending cycle of persistent compounds working their way through the air, onto the land and into the water.

A 2019 report from the Puget Sound Ecosystem Monitoring Program presents an overview of selected recent monitoring and research activities focused on toxic contaminants in the Salish Sea. 

As the region's population grows, scientists say we can expect to see increasing amounts of nitrogen and other elements flowing into Puget Sound. Known as “nutrients” these elements are naturally occurring and even necessary for life, but officials worry that nutrients from wastewater and other human sources are tipping the balance. That could mean big problems for fish and other marine life, gradually depleting the water of oxygen and altering the food web.

Researchers are trying to determine which chemicals in stormwater are contributing to the deaths of large numbers of coho salmon in Puget Sound. It has prompted a larger question: What exactly is in stormwater, anyway?

A new study shows a surprising decline in some toxic chemicals in Puget Sound fish, while levels of PCBs increased in some cases. Scientists say the study shows that banning toxic chemicals can work, but old contaminants remain a challenge as they continue to wash into Puget Sound.

Toxic chemicals have been showing up in Puget Sound fish for more than a century, but consistent testing over the past 30 years has helped to reveal some unusual patterns of pollution.

A 2017 report from the Puget Sound Ecosystem Monitoring Program presents an overview of selected recent monitoring and research activities focused on toxic contaminants in the Salish Sea. 

The Puget Sound Ecosystem Monitoring Program (PSEMP) is an independent program established by state and federal statute to monitor environmental conditions in Puget Sound. 

The Puget Sound Ecosystem Monitoring Program released its fifth annual Marine Waters Overview this week. The report provides an assessment of marine conditions for the year 2015 and includes updates on water quality as well as status reports for select plankton, seabirds, fish and marine mammals.

A 2015 report from the Whatcom Conservation District and Whatcom County describes a pilot watershed characterization study focusing on the Terrell Creek and Birch Bay areas. The report and related appendices are available for download. 

The Lower Duwamish Waterway in Puget Sound was designated a Superfund cleanup site in 2001. Its legacy of contamination predates World War II and the waterway continues to pollute Puget Sound through stormwater runoff.

The Puget Sound Fact Book brings together statistics and other information about the health and makeup of the Puget Sound ecosystem. Areas of focus include climate change, geography, water quality, habitats, human dimensions and regional species. The fact book was prepared for the Encyclopedia of Puget Sound with funding from the Environmental Protection Agency and the Puget Sound Partnership.

The Puget Sound Ecosystem Monitoring Program (PSEMP), along with partners from the US EPA Columbia River Program and USGS Oregon Water Science Center, have developed a framework for prioritizing monitoring of Contaminants of Emerging Concern (CECs) in the Pacific Northwest.

New research presented at the 2014 Salish Sea Ecosystem Conference shows that some of the greatest dangers to Puget Sound marine life come from our common, everyday activities. These pervasive sources of pollution are so woven into our lives that they are almost invisible to us, but it’s becoming impossible to ignore their effects.

Several research groups in the region are investigating biological markers and/or impacts of Contaminant of Emerging Concern (CEC) exposure in different organisms.  An abstract describing each study is included below.  Also included are links or contact details for further information about each project.

Several studies have been performed to determine the occurrence of selected Contaminants of Emerging Concern (CECs) in the environment.

Thousands of different compounds are produced and used as part of our daily lives.  Examples include pharmaceuticals (NSAIDs, birth control pills, etc), personal care products (sun screen agents, scents, preservatives, etc), food additives (artificial sweeteners) and compounds used in industrial and commercial applications (flame retardants, antibiotics, etc).  Advances in analytical methods have allowed the detection of many of these compounds in the environment.

Puget Sound Stream Benthos is a data management project which monitors benthic invertebrates in streams and rivers in the Puget Sound region. The system is maintained and operated by King County and was the result of a joint effort between King, Pierce, and Snohomish Counties.