Water Quality
While our drinking water remains very clean and safe, the water quality in Lake Whatcom has been declining in recent decades due to ongoing changes and activities in the Lake Whatcom watershed. Learn more from the links below.
Why is there a water quality problem? What is the problem?
Watch this short Lake Whatcom Water Quality Overview video.
Drinking Water Quality
To meet federal drinking water regulations and to provide the public with important information about their drinking water quality, all public water utilities are required to provide annual drinking water reports to their customers. Lake Whatcom provides drinking water for the City of Bellingham and Lake Whatcom Water and Sewer District customers.
Lake Water Quality
Lake Whatcom has been the subject of monitoring efforts since the early 1960s. Western Washington University's (WWU) Institute for Watershed Studies (IWS) conducts long-term water quality monitoring in cooperation with Lake Whatcom Management Program partners. The current monitoring program began in 1988.
Visit the Institute for Watershed Studies to access lake water quality data and learn more about the monitoring program (click the Lake Whatcom link in the top menu).
The Lake Whatcom Management Program also conducts tributary monitoring on the water quality of streams flowing into the lake.
Lake Whatcom Tributary Monitoring Program Phase 3 Report without appendices (48 pages) (2021)
Lake Whatcom Tributary Monitoring Program Phase 3 Report with appendices (556 pages) (2021)
Lake Whatcom Management Program partners also assess impacts from on-site sewage systems (also known as OSS or septic systems) on Lake Whatcom's north shore.
Lake Whatcom North Shore On-Site Sewage System Leachate Detection Project Report (2017)
Lake Whatcom On-Site Sewage System Impact Assessment Report (2020)
Improving Lake Water Quality
In 1998, Lake Whatcom was placed on Washington's 303(d) list for polluted water bodies because it failed to meet state water quality standards for dissolved oxygen. As a result, the State Department of Ecology completed the Lake Whatcom Watershed Total Phosphorus and Bacteria Total Maximum Daily Load (TMDL) water quality study and improvement reports. These TMDL documents inform our current cleanup plan for Lake Whatcom. Specific cleanup requirements are included in the city and county's municipal stormwater permit. To learn more about this process, visit the following Ecology website pages:
Western Washington Phase II Municipal Stormwater Permit
The federal Clean Water Act National Pollutant Discharge Elimination System (NPDES) requires cities and counties to manage stormwater runoff within their boundaries to protect water quality. The City of Bellingham and Whatcom County have comprehensive stormwater management programs designed to reduce impacts from stormwater runoff entering our our local streams, lakes, and bays and meet the requirements of their municipal stormwater permits, commonly called the NPDES permit.