While the City of Bellingham produces some of the cleanest drinking water in the nation, the water quality of Lake Whatcom has started to decrease in recent decades due to a number of water quality challenges.
Drinking Water Quality
Despite lake water quality challenges, the City is committed to supplying some of the safest drinking water in the country.
Water Quality Reports
- 2024 Drinking Water Quality Report (PDF June 2025)
- 2023 Drinking Water Quality Report (PDF May 2024)
- 2022 Drinking Water Quality Report (PDF May 2023)
Water Quality Reports from previous years are available upon request. Please contact the Water Quality Specialists at the City’s Lab at (360) 778-7870 for more information.
More Information
- Drinking Water Quality Frequently Asked Questions (PDF)
- Drinking Water Quality Monitoring
- Water Treatment Process
Lake Water Quality
The City works closely with the Western Washington University Institute for Watershed Studies (IWS) to monitor water quality trends in Lake Whatcom. Currently the lake is sampled in five locations with 12 tributaries monitored throughout the year. IWS provides detailed annual reports.
Improving Lake Water Quality
In 1998, the Washington Department of Ecology (ECY) placed Lake Whatcom on Washington’s 303(d) list for polluted water bodies because it failed to meet state water quality standards for dissolved oxygen and phosphorus. Ecology, City and County staff work together to develop a watershed management strategy that will enable Lake Whatcom to safely meet state water quality standards in the future.
- Lake Whatcom Water Quality Improvement Project (TMDL) (Department of Ecology website)
- TMDL Study Findings (Department of Ecology publication) (PDF)
- Focus on Lake Whatcom TMDL Fact Sheet (Department of Ecology publication) (PDF)
