Sandwiched between the Olympic and Cascade mountain ranges, Puget Sound's urban areas receive up to 40 inches of rain each year. Historically, most of this water soaked into the ground or was taken up by plants. In forested areas in the Pacific Northwest, evergreen trees transport about 40% of rainfall back to the atmosphere through their needles. The remaining water filters through other plants and the soil. The ecosystem is driven by this water cycle, but over the past 100 years, human development has drastically altered this natural pattern.
Urban areas were originally designed to move stormwater quickly and efficiently downstream through a series of drains, pipes, and sewers. Flood prevention was the main reason for getting stormwater out of the city fast, but over the years municipalities have come to realize that speedy water removal is actually detrimental to the health of Puget Sound.
Without the filtering effect of plants and soil, surface runoff increases and stream flows become "flashier"—surges in runoff are more frequent and more intense. This means greater flooding, and more polluted water flowing into Puget Sound.
Source: "Stormwater fixes could cost billions"; Salish Sea Currents.
Runoff from rain and melting snow is one of the leading causes of pollution in Puget Sound. Here are selected facts related to stormwater, its prevalence, how it affects the Puget Sound ecosystem, and its environmental and economic impacts.
Timeline: The search to find a chemical that kills coho salmon in urban streams
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.
Scientists hunt down deadly chemical that kills coho salmon
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.
The history and chemistry of tires
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.
Combining bugs and chemistry in Soos Creek stormwater study
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.
Toxics in Fish Implementation Strategy
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.
Healthy stream, healthy bugs
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.
Airport offers a glimpse at tightening stormwater regulations
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?
Stormwater fixes could cost billions
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.
Air contaminants, such as mercury and PCBs, undermine the health of Puget Sound
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.
2018 Salish Sea toxics monitoring synthesis: A selection of research
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.
Does Puget Sound need a diet? Concerns grow over nutrients
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.
What is killing the coho?
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?
PCBs in fish remain steady while other toxics decline
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.
Monitoring helps to reveal hidden dangers in the food web
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.
2016 Salish Sea Toxics Monitoring Review: A Selection of Research
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.
Puget Sound Ecosystem Monitoring Program
The Puget Sound Ecosystem Monitoring Program (PSEMP) is an independent program established by state and federal statute to monitor environmental conditions in Puget Sound.
2015 Puget Sound Marine Waters Overview
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.
Birch Bay characterization and watershed planning pilot – taking action
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.
Persistent contaminants in Puget Sound: Overcoming a toxic legacy
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.
Puget Sound Fact Book
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.
Framework for prioritizing monitoring of CECs in the Pacific Northwest
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.
Citizens now the leading cause of toxics in Puget Sound
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.
Regional investigations into the effects of CECs
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.
Regional monitoring of CECs in the Salish Sea
Several studies have been performed to determine the occurrence of selected Contaminants of Emerging Concern (CECs) in the environment.
Contaminants of emerging concern in the Salish Sea
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.
Featured resource: Puget Sound Stream Benthos
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.