Water Quality Improvement Project
Lake Whatcom Area:

Current Developments

The comment period has closed. There were 109 comments by 19 commenters. Ecology is reviewing the comments and developing a response to them.

February 2013 - Lake Whatcom water quality report out for public review

Ecology worked with the city of Bellingham and Whatcom County officials to update a 2008 report to include guidance and strategy to limit pollutants entering Lake Whatcom.

The report recommends that in order to protect Lake Whatcom and the drinking water for 100,000 people the amount of pollutants entering the lake has to be substantially reduced.

Ecology is seeking public review and comments on the report for the next 90 days before submitting it to the U.S. Environmental Protection Agency.

The final report is available for public review, and Ecology accepted comments through May 28, 2013. Comments were submitted to:

Steve Hood
Bellingham Field Office
WA State Department of Ecology
1440 10th St., Suite 102
Bellingham, WA 98225

Review the report at the following locations:

Lake Whatcom, the main source of drinking water for the city of Bellingham and other communities around the lake, is suffering from low levels of oxygen. The root cause of the problem: increased levels of phosphorous and fecal bacteria entering the lake.

According to the report, two things need to happen for the lake to meet water quality standards: approximately 87 percent of the current development around the lake needs to be able to store and filter stormwater like a forest; and bacteria levels in the most contaminated streams need to be reduced up to 96 percent.

It will be the city’s and county’s ongoing responsibility to achieve these goals.


Lake Whatcom is a large natural lake in Whatcom County. The northwest end of the lake lies within the city of Bellingham, and 22 small watersheds drain into the lake. Lake Whatcom serves as the drinking water source for about 96,000 people in the Bellingham area. The lake is popular for recreation, and the area around it has become a popular place to live.

Water quality problems in Lake Whatcom have triggered a water quality improvement project by Ecology. These projects begin with a study of pollutants. For Lake Whatcom, Ecology is working to determine the allowable limits of phosphorus in the lake and fecal coliform bacteria in the tributaries, to meet water quality standards. Ecology will work with local governments to determine how to achieve those limits. (See Study Area map)

Water quality issues

Based on historic data, Ecology officially recognized in 1998 that Lake Whatcom fails to meet state standards for dissolved oxygen. This put Lake Whatcom on the state’s 303(d) list of impaired water bodies. Also, 11 tributaries flowing into the lake have fecal coliform levels that are too high.

On January 10, 2011 the city of Bellingham filed a petition to have the Lake Whatcom Watershed closed to additional groundwater withdrawals. The city’s petition argues that phosphorus-laden runoff from cleared and developed land is impairing the city’s ability to exercise its municipal water right from Lake Whatcom and supply water to nearly 100,000 people. Elevated levels of phosphorus have resulted in low dissolved oxygen levels and excessive growth of algae blooms in the lake that has slowed operations at the city’s water treatment plant. The algae blooms clog water filters and require the city to use millions of gallons of treated water to flush the filters.

Since 1990, the city and county have worked to develop a strategy to improve water quality in Lake Whatcom to meet state and federal standards for dissolved oxygen. The lake is on the state’s 303(d) list of impaired water bodies, and local governments must meet the pollution limits identified through the state water quality improvement process (called a TMDL). But that process is not intended to address these immediate concerns about the city’s compromised water rights, and immediate concerns about the continuing degradation of the environment in the watershed.

Under the Administrative Procedures Act, Ecology can:

  • Grant Bellingham’s petition.
  • Deny the petition with an explanation.
  • Deny the petition but provide an alternative means to address the concerns of the petition.

Ecology chose the third option and accepted Whatcom County’s proposal to amend its development regulations in the Lake Whatcom watershed in the next several months to ensure no additional phosphorus contamination of the lake. A letter from the county executive to Ecology states the county’s goals of amending the regulations to:

  1. Prevent additions of phosphorus to Lake Whatcom from new development projects.
  2. Achieve a consistent and predictable set of development regulations.

Ecology believes if the amended regulations are adopted and effectively implemented, the goals of the city’s petition will be achieved. If the amendments are not adopted or properly implemented, Ecology reserves the right to take additional regulatory action to ensure that our water quality goals for the lake are achieved.

Lake Whatcom's use for drinking water and its high potential to be degraded further have made it a priority for a state water quality improvement project, also known as a Total Maximum Daily Load (TMDL) study.

Monitoring surveys were completed in 2002 and 2003, and Ecology completed a draft water quality study to identify the limits for phosphorus, the root of the dissolved oxygen issue.

The final TMDL study findings will be the basis for decisions local governments make about the lake's future. The city of Bellingham and Whatcom County will work with the state to develop a plan for meeting the limits established in the study. The plan will then go to the U.S. Environmental Protection Agency for review. If the EPA finds that the TMDL and the strategy to meet its limits are sound, EPA will approve the TMDL for Lake Whatcom.

Ecology requested public comment on the Draft Lake Whatcom Watershed Total Phosphorus and Bacteria Total Maximum Daily Loads — Water Quality Study Findings. The public comment period ended on September 17, 2008.

Since 2009 Ecology has worked with the city of Bellingham and Whatcom County to determine what tools they will use to implement the TMDL. We are trying to best characterize current conditions. We plan to run models that estimate how much pollution comes from the watershed and how the lake will respond.

The water cleanup plan will be based on how much pollution reduction is necessary based on our new estimate of existing conditions, with no reserve for new development.

Why this matters

Fecal coliform bacteria originate in human and animal waste. Runoff carries the bacteria from the ground and from failing septic systems into the lake. Eleven tributaries feeding Lake Whatcom fail to meet state standards for fecal coliform bacteria. The bacteria create a health risk for people who work or play in and around the water.

Phosphorus is the main cause of Lake Whatcom’s low-oxygen problem. Phosphorus occurs naturally, but development increases phosphorus entering the lake in stormwater. Computer predictions show the lake would meet state standards for oxygen if there was 86 percent less development than existed in 2003. Since then, zoning laws have allowed more development in the watershed.

Sources: Runoff from bare soil and developed areas. Phosphorus occurs naturally in soil and human and animal waste, and is added to some detergents.

Connection to algae and oxygen: Phosphorus feeds algae growth. Bacteria that consume dying algae deplete the oxygen that fish and other aquatic life need to survive. When oxygen levels are low, phosphorus is released from lake sediment and re-enters the water, perpetuating the cycle. The dissolved oxygen levels in Lake Whatcom fail to meet state water quality standards now, and they have the potential to get much worse, making the problem much harder to fix.

Treatment of drinking water: Excess phosphorus creates larger algae blooms, which require more treatment to make the water safe for drinking. That process creates more trihalomethanes, a byproduct that some studies link to cancer.

Effect of development: Roofs, driveways and lawns interrupt the absorption and filtration provided by forests and soils, instead sending phosphorus-laden stormwater rushing to the lake. Communities must modify existing and future development to create the same effect as removing development.

Technical information

Unless otherwise specified, the following documents are Ecology publications:

Lake Whatcom Watershed Total Phosphorus and Bacteria Total Maximum Daily Loads: Volume 2. Water Quality Improvement Report and Implementation Strategy

Lake Whatcom Watershed Total Phosphorus and Bacteria Total Maximum Daily Loads: Volume 1. Water Quality Study Findings

Dissolved Oxygen in Lake Whatcom/Trend in the Depletion of Hypolimnetic Oxygen in Basin I 83-97

Quality Assurance Project Plan: Lake Whatcom TMDL Study

Quality Assurance Project Plan: Characterization of Groundwater Discharge to Lake Whatcom

Lake Whatcom Total Maximum Daily Load Groundwater Study

Related information

Lake Whatcom water quality still slipping, data shows (The Bellingham Herald article, March 17, 2011)

Ecology accepts plan for better protection of water quality in Lake Whatcom (Ecology news release - March 11, 2011)

State rejects well drilling ban, approves county plan for Lake Whatcom safeguards (The Bellingham Herald article, March 11, 2011)

Focus on Lake Whatcom TMDL: Draft study identifies limits for Lake Whatcom phosphorus and bacteria

Reducing Phosphorus Pollution to Improve Water Quality (Water Quality web site)

WRIA 1: Nooksack Watershed Information (Environmental Assessment Program web site)


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Last updated June 2013
  Water resource inventory area (WRIA) 1 map, Washington State.


WRIA(s): #1 (Nooksack)
County: Whatcom

Water-body Name:
Lake Whatcom

Fecal coliform bacteria

# of TMDLs: ---

Under development
Study for phosphorus and bacteria issued

Contact Info:
Steve Hood
Phone: 360-715-5211
Email: Steve.Hood@ecy.wa.gov

Bellingham Field Office
Department of Ecology
1440 - 10th St., Suite 102
Bellingham, WA 98225-7028