Freshwater Quality | US EPA

Updated June 2021 based on data available through December 2017.

Neutral Trend

20 rivers were assessed with the Freshwater Quality Index (WQI): 14 in Washington, covering most of the major river basins entering Puget Sound; and 6 in British Columbia (BC), covering a range of land-use types. Of the twenty rivers assessed since 2010, two rivers showed decreasing water quality. In particular, the Fraser River score declined from our Good classification to the Fair/Marginal classification.

Though another ten of the rivers occasionally exceeded water quality guidelines, improving water quality scores were observed in three rivers (Cedar, Elwha and Snohomish). 13 of the rivers either regularly or occasionally exceeded water quality guidelines, with a declining pattern most evident for the lower Fraser and Quinsam Rivers in BC, and indications of decline in the Nisqually and Deschutes Rivers in Washington.

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About Freshwater Quality

Water quality problems such as toxic algae in lakes and streams can flow downstream and impact the entire ecosystem.

Clean water from streams and rivers that flow into the Salish Sea is essential for maintaining a healthy ecosystem. Water quality and habitat problems in lakes and streams can continue to flow downstream and impact the entire ecosystem, including:

• Excess nutrients from wastewater discharges.
• Pollutant loads from stormwater, particularly from roads, highways and parking lots.
• Runoff from some agricultural lands.
• Warmer water temperatures associated with the loss of riparian areas along streams.
• Changes in hydrology (water flow).

This is why watershed-scale planning and management approaches are so important to protecting and restoring the water quality and related beneficial uses of our fresh and downstream estuarine waters.

What is a Fresh Water Quality Index?

The Freshwater Quality Index (WQI) is a tool developed by scientists to help evaluate the quality of water in these streams and rivers. It summarizes large amounts of water quality data into a single “score” from 1 to 100. Higher scores reflect cleaner water.

A water quality index is useful for easily comparing water quality across rivers, but since it is an aggregation of data, it can obscure some of the component results. While it can be helpful for interpretation of how streams are doing in general, it is not designed for site-specific analysis.

The Freshwater Quality Index is based on established water quality guidelines and criteria for physical and chemical properties of the waterbody, such as sediments, nutrients, temperature, contaminants and the amount of dissolved oxygen within the water.

In this report, two water quality indices were used evaluate the freshwater ecosystems that flow into the Salish Sea:

• Environment and Climate Change Canada evaluated streams in the Georgia Basin using the Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI).
• The Washington Department of Ecology’s Stream Monitoring Program developed and uses the Freshwater Quality Index tool to evaluate the quality of rivers in Puget Sound.

Water quality index scores for the CCME WQI and Washington’s WQI have individual range categories for determining good, fair, marginal, and poor quality scores. For the purposes of the combined Salish Sea indicator, they have been placed into different ranges that help describe the quality of the water across both indices.

These are the ranges that were established for this report:

• WQI scores from 80-100 indicate high water quality, meaning that water quality rarely exceeds guidelines, and if so, only by a narrow margin.
• WQI scores from 70-79 indicates fair or marginal water quality that sometimes exceeds guidelines, possibly by a wide margin.
• WQI scores below 69 indicate poor water quality that often exceeds guidelines by a wide margin.

Note that these ranges differ from the ranges established for either of the individual water quality indexes that have been combined here for easier comparison.

The average Freshwater Quality Index scores for 20 major rivers from 2000 to 2017 show that:

• 6 rivers have excellent to good water quality (80-100).
• 9 rivers have fair to marginal water quality (70-80).
• 5 rivers have poor water quality (below 69).

WQI scores for Salish Sea rivers from 2000-2017. Click chart for larger view.
Map of Salish Sea rivers and their WQI index rating (green-yellow-red) from 2000-2017. Click map for larger view.

Why Is It Important?

“The Skokomish Tribe is wholly devoted to restoring the Skokomish watershed and its resources — not just for the next five years, not just for another 40 years, but forever. We must continue healing the environment that we depend on for survival. The health and well-being of the Skokomish watershed is vital to the Skokomish tribal culture, tradition, subsistence and economy.”

Clean, cold water is critical for the health of stream and river ecosystems, particularly where salmon spawn and migrate. Even small changes in stream temperature can affect salmon populations.

Poor stream water quality, for example due to contaminants, pathogens, or excess nutrients, can impact downstream rivers and marine water quality. Contaminants can directly affect species through both acute and longer-term food-web based responses. Adding nutrients to marine waters can result in algal blooms that may lower oxygen levels and affect many species and uses of these waters. Pathogens directly affect recreation and shellfish harvests. Further, freshwater stream habitats and biological communities are impacted by a variety of stressors that are associated with land use conversion and urbanization, including but not limited to excessive fine sediment, loss of riparian and wetland vegetation and scouring high flows due to accelerated stormwater runoff.

Drinking water, irrigation, recreation, and other uses can also be affected by poor stream quality.

Sustainable Perspectives

Between 1858 and 1870, the fur trade gave way to the gold rush as gold seekers flooded the Fraser River Basin. Coined the “hungry people” by the Sto:lo, gold seekers made their way up the Fraser River, bringing mining, road construction and boom towns to the region, impacting salmon spawning habitat and reducing water quality.

To separate gold from sand at Fort Hope, standard mining operations used 40 to 50 pounds (18 to 23 kilograms) of mercury a day, while smaller operations used 8 to 10 pounds (4 to 5 kilograms). Today, beads of mercury (or “quicksilver”) can be found by digging down only a few feet into the sands of Emery’s Bar.

The impacts of mercury on sturgeon and other aquatic life – as well as First Nations who depend on them – have yet to be studied.

Source: Keith Thor Carlson, Sto:lo – Coast Salish Historical Atlas

Why Is It Happening?

Four major factors that affect freshwater are:

1. Stormwater runoff due to increasing development as buildings, roads, parking lots, and other paved areas prevent the absorption of rainwater. Paved surfaces also collect pollutants like chemicals, oils and fertilizers, and also many small particles from tires, brake pads and types of road dusts and salts. These pollutants are then picked up by rainwater and carried to the stormwater system and downstream into our estuary and marine waters.
2. Loss of forested riparian and wetland areas along streams due to development, agricultural operations, and forestry practices. Wetlands can hold freshwater for a period of time, allowing vegetation and microbes to break down some of the suspended contaminants and let suspended biologic material settle out of the water.
3. Loss of forested areas in the upper watersheds due to timber harvesting. More forested areas in the area will absorb water and control sediment transfer into freshwater streams. Forests also shade freshwater streams, providing a variety of different habitats for aquatic organisms and plants. High densities of logging roads in forested areas can also change the hydrology of some watersheds resulting in pulse flooding, stream erosion and downstream sedimentation problems.
4. Industrial, agricultural, and other urban pollutants that are intentionally or unintentionally discharged directly into freshwater systems. Unintentional connections to freshwater systems can prevent pollutants from reaching treatment systems designed to collect and remove chemicals from the water used in agriculture or industry. These chemicals then travel to freshwater systems and can have impacts on aquatic organisms.

Recent studies have shown that stream quality can be affected when as little as 7% of the total watershed area is covered by impervious (paved) surfaces.

The amount of surrounding vegetation plays a role in stream quality too. Impacts to stream quality can be observed when vegetative cover (e.g. forested areas) is reduced to less than 65% of the total watershed area. The main types of land uses (e.g. urban, agricultural, forested) within each river’s watershed will largely determine its water quality.

Overall, the rivers with ratings in the poor category are almost all located in areas with urbanized and agricultural land use. These urbanized watersheds show substantial changes in hydrology and toxic contaminants, and agricultural land practices often lead to nutrient loadings that can flow into nearby waters. Rivers in the excellent to good category are usually located in remote or forested land use areas, where wetlands and vegetation along streambanks can filter stormwater and provide shade to waterways.

What’s Being Done About It?

Governments, industries, and non-profit organizations are working together to help reduce stormwater runoff from developed lands by implementing green infrastructure practices, planting trees along streambanks, restoring wetlands, upgrading older wastewater treatment plants to more effectively remove pollutants, and adopting best management practices for agriculture and forestry.

Below are examples of work being done by agencies and organizations to help improve stream quality:

The following links exit the site

Georgia Basin

• The government of Canada implemented the Wastewater Systems Effluent Regulations (WSER) under the federal Fisheries Act in 2012. Operators have until 2020, 2030, or 2040 to upgrade their treatment systems to meet WSER requirements, depending on risk. In the Salish Sea, two major wastewater systems will be updated to meet WSER standards by the end of 2020, three systems must be upgraded by 2030, and only one system has been granted the maximum deadline (until 2040) for upgrading its treatment level.
• By June 2019, there were 151 chemical substances listed as toxic under the Canadian Environmental Protection Act, 1999. Chemical assessments are conducted by Environment and Climate Change Canada under the Chemicals Management Plan (CMP). A new phase of the CMP was launched in 2016 to support and investigate the risks posed by an additional 1550 priority chemicals.
• Environment and Climate Change Canada has been modernizing regulations related to aquatic environments under the Fisheries Act. The Metal and Diamond Mining Effluent Regulations came into force on June 1, 2018, and introduced new limits for several substances that could be released into waters by mining operations.
• British Columbia’s Living Water Smart vision is a strategy for sustainable water stewardship that includes actions such as ensuring wetlands and waterways will be protected and rehabilitated, and that land activities will not negatively impact our water. A key commitment of Living Water Smart was to improve water laws, and in 2016 the new Water Sustainability Act came into effect, laying out seven areas of improvement.
• In December 2019, British Columbia increased oversight on water use by small-scale placer mining projects. Placer mining occurs in streambeds and is the type of mining that describes a range of activities from one person working with a gold pan to using larger equipment to dig through stream banks and using large volumes of water to wash loose sediments. The new regulations, part of the Water Sustainability Act, now require placer miners using large mechanical tools to apply for authorization to use any water resources in their operations.
• Local governments such as Metro Vancouver are developing integrated stormwater management plans and adopting best management practices in the Georgia Basin. As of 2016, many plans are complete and being put into action. Infrastructure planning grants for local governments from the British Columbia Ministry of Municipal Affairs and Housing are available for developing or improving integrated stormwater management plans.

Puget Sound

• In Puget Sound, local governments are beginning to implement new stormwater permit requirements including the use of Low Impact Development (LID) stormwater techniques to reduce the impact of stormwater on fresh waters. There are now dozens of LID practices in Washington with some popular examples including rain gardens, permeable pavement and green roofs. The Washington Department of Ecology is working with regional partners to establish LID best practices and requirements and is providing financial assistance to local governments to implement these new requirements.
• The Washington State University-Puyallup Research Station, has been testing and designing bioretention, permeable pavement and other Best Management Practices for treating pollutants and reducing impacts to local hydrology.
• The Washington Department of Transportation (WSDOT) is implementing new stormwater permit requirements to reduce the impacts of stormwater from state highways on fresh water streams. A new permit became effective in 2019 requiring WSDOT to conduct baseline monitoring and monitoring the effectiveness of best management practices.
• The Puget Sound Partnership, through the Puget Sound Action Agenda, has made stormwater runoff one of its highest priorities helping to direct millions of dollars into stormwater management plans and practices, including the advancement of green infrastructure, to protect local stream and rive habitats from polluted runoff and changes in local hydrology.
• The Washington Department of Ecology outlines technology-based effluent limits for wastewater treatment plants to ensure that released by-products don’t harm the natural environment. A Water Treatment Plant General Permit came into effect in September of 2019 that has requirements and conditions to protect rivers and downstream waterbodies.
• Where rivers and streams are already polluted or degraded to the extent that water quality standards are not being met, the Washington Department of Ecology may require that Total Maximum Daily Loads (TMDLs) be established to cap and reduce future pollutant loadings. Visit EPA’s Impaired Waters and Stormwater page for more information.
• Washington’s Stormwater Action Monitoring Program aims to improve stormwater management, reduce pollution, improve water quality, and reduce flooding. They do this by working together to measure stormwater impacts on the environment and evaluate the effectiveness of efforts to manage stormwater.

Sustainability in Practice

Restoring the Cowichan and Koksilah Watersheds

The Cowichan River has been important to people living in and downstream of the watershed for millennia. The Cowichan peoples describe the Cowichan and Koksilah river drainages as a prized source of salmon, considered a gift from the First Ancestor, and located their winter villages along the rivers’ paths to the Salish Sea.

As British Columbia grew, the Cowichan River was altered to accommodate log driving and other uses. The Cowichan watershed basin now has influences from industrial, agricultural, and urban land uses. In 2010, the Cowichan Water Board was created as a partnership between the Cowichan Tribes and the Cowichan Valley Regional District to understand what key factors were driving the declines in water quality in the watershed and to start work on restoring the watershed’s health.

There is now much work underway in the Cowichan and Koksilah watersheds. In 2015, with funding from Environment and Climate Change Canada’s Eco Action Community Funding Program, Fisheries and Oceans Canada, and other partners, the Cowichan Lake and River Stewardship Society organized a riparian (streamside) planting project to improve the watershed’s health.

This 2015 planting project focused on re-introducing native plants in nine locations, with four sites along Lake Cowichan and five sites along the Cowichan River. Vegetation along streambeds can act as a temperature moderator by providing shade, act as a biological and physical filter by absorbing nutrients and sediments from surface runoff, and reducing sediment transport downstream as well as stabilizing slopes along streams and avoiding additional streambank erosion.

The Cowichan Watershed Board completed additional studies in 2017 and 2018 to assess the water quality the Koksilah River and other tributaries of Cowichan Bay. In 2018 Canada’s Coastal Restoration Fund also provided additional funding for 5 years to the Cowichan Tribes to continue restoration work on the Cowichan and Koksilah rivers.

Depave Puget Sound

A playground restoration project in Tacoma, Washington is helping to reduce the impact that urban areas have on freshwater quality in the Puget Sound. Depave Puget Sound, a regional partnership of agencies and community members along with the Pierce County Conservation District, completed a successful “depave” project in 2019. A paved schoolyard at Holy Rosary Bilingual Academy was converted into a thriving greenspace that features a grassy soccer field ringed by trees.

Ripping up the pavement and replacing it with grass took the work of many volunteers, including the students and parents at the school. The removal and disposal of the paved surface now allows the ground to soak up more water when it rains, reducing the total amount of polluted stormwater entering nearby freshwater streams. In addition, airborne pollution from the nearby highway can now settle onto plants or into the ground, where microbes can work to break down pollutants before they can get washed downstream reducing the load of contaminants that end up in Salish Sea waterways.

Every year, this project will prevent an estimated 360,000 gallons of polluted stormwater from entering Puget Sound waterways.

Learn More

Learn more about freshwater quality and some of the work our partners are doing.

The following links exit the site

Five Things You Can Do To Help

1. Keep streams shaded. Trees and bushes keep the water cool for fish and help stabilize the banks from erosion. Watch for stream restoration projects in your community.
2. Use techniques such as natural landscaping, rain gardens, rain barrels, green roofs and permeable paving that conserve water and allow rain to soak into the ground. See EPA’s landscaping tips for ideas.
3. Never dump unused medicine and chemicals into household toilets and sinks or outside where they can get into ditches or storm drains. See if your community has a household hazardous waste collection facility that will take your old or unused chemicals.
4. Scoop your pet’s poop. Pet waste is full of bacteria that can get washed into waterways during rain storms. Bag it and place it in the trash.
5. If you keep livestock, follow manure management practices to help reduce agricultural runoff. Learn more about what you can do to manage animal waste.

References

Below is a listing of references used in this report.

1. Canadian Council of Ministers of the Environment. 2001. Canadian Water Quality Guidelines for the Protection of Aquatic Life: CCME Water Quality Index 1.0 Technical Report. Winnipeg, Manitoba.
2. Canadian Council of Ministers of the Environment. 2017. Canadian Water Quality Guidelines for the Protection of Aquatic Life: CCME Water Quality Index User’s Manual. Winnipeg, Manitoba.
3. Environment Canada. 2015. Data Sources and Methods for the Freshwater Quality in Canadian Rivers Indicator. Catalogue Number En4-144-64-2015-eng.pdf. ISBN 978-0-660-02122-5.
4. Hallock, D. 2002. A Water Quality Index for Ecology’s Stream Monitoring Program. Washington State Department of Ecology, Olympia, WA. 17 pp. + appendices. Publication No. 02-03-052. https://fortress.wa.gov/ecy/publications/summarypages/0203052.html.
5. Washington Department of Ecology. 2014. River and Stream Water Quality Monitoring Report: Water Year 2013. Publication Number 14-30-047.
6. Carlson, K.T. 2001. A Sto:lo Coast Salish Historical Atlas. Published by Sto:lo Nation, Chilliwack, BC and Douglas and McIntyre Ltd., Vancouver, BC. 208 p.
7. Environment Canada. 2001. Threats to Sources of Drinking Water and Aquatic Ecosystem Health in Canada. National Water Research Institute, Burlington, Ontario. NWRI Scientific Assessment Report Series Number 1. 72 p.
8. Northwest Indian Fisheries Commission. 2012. State of Our Watersheds Report. 336 p.
9. Pike, R.G., E.L. Young, J.D. Goetz and D.L. Spittlehouse. 2017. Cowichan River: A Summary of Historical Disturbances, Water Use Pressures and Streamflow Trends. Water Science Series. WSS2017-05. Prov. BC., Victoria, B.C.
10. Wong, C., and M. Rylko. 2014. Health of the Salish Sea as measured using transboundary ecosystem indicators, Aquatic Ecosystem Health & Management, 17:4, 463-471, DOI: 10.1080/14634988.2014.980209.
11. Government of Canada. Wastewater Management. https://www.canada.ca/en/environment-climate-change/services/wastewater/management.html.
12. Government of Canada. Wastewater Systems Effluent Regulations: registry of transitional authorizations. https://www.canada.ca/en/environment-climate-change/services/wastewater/regulations/registry-transitional-authorizations.html.
13. Province of British Columbia. Living Water Smart. https://www2.gov.bc.ca/gov/content/environment/air-land-water/water/water-planning-strategies/living-water-smart.
14. Natural Resources Canada. Metro Vancouver’s Stormwater Management Program. https://www.nrcan.gc.ca/sites/www.nrcan.gc.ca/files/earthsciences/pdf/mun/pdf/vancouver_e.pdf.
15. Washington Stormwater Center. LID Database. https://www.wastormwatercenter.org/lid-database.
16. Washington Department of Ecology. 2008. Focus on Stormwater. https://www.epa.gov/sites/production/files/2015-11/documents/0810043.pdf.
17. Washington Department of Ecology. Water Treatment Plant General Permit. https://ecology.wa.gov/Regulations-Permits/Permits-certifications/Water-treatment-plants.
18. Government of Canada. Risk management of chemical substances. https://www.canada.ca/en/health-canada/services/chemical-substances/canada-approach-chemicals/risk-management.html.
19. Government of Canada. Risk Management Plan. https://www.canada.ca/en/health-canada/services/chemical-substances/chemicals-management-plan.html.
20. Government of Canada. Metal and Diamond Mining Effluent Regulations. https://laws-lois.justice.gc.ca/eng/regulations/SOR-2002-222/FullText.html.
21. Government of Canada. Forward Regulatory Plan 2018 to 2020, Environment and Climate Change Canada, Chapter 3. https://www.canada.ca/en/environment-climate-change/corporate/archive/forward-regulatory-plans/2018-2020/fisheries-act.html.
22. Province of British Columbia. Updated rules for water use in mineral exploration, mining. https://news.gov.bc.ca/releases/2019ENV0124-002472.
23. Cowichan Watershed Board. 2018. A guide to the Cowichan Watershed Board’s aspirational targets for watershed health. https://cowichanwatershedboard.ca/wp-content/uploads/2019/04/CWB-Targets-for-Watershed-Health-2018-Update.pdf.
24. Cowichan Nation. Pre-European Contact. https://www.cowichantribes.com/about-cowichan-tribes/history/pre-european-contact.