Lake Threats

Photo by B. Richter, 2008.

Since 1962, Lake Whatcom's water quality has been monitored by staff from Whatcom County, the City of Bellingham, and Western Washington University's Institute for Watershed Studies. In recent decades, the water quality in Lake Whatcom has been deteriorating due to increased phosphorus inputs that are resulting in algal blooms and depleted oxygen levels. In 1998, Lake Whatcom was placed on Washington's list of polluted waters because it no longer met the state's dissolved oxygen level requirements. Today, the City, County, and Lake Whatcom Water and Sewer District are working together to implement a plan to meet water quality standards. In the meantime, Lake Whatcom is also vulnerable to many additional threats.


Stormwater runoff is the most common cause of water pollution. In Whatcom County, most storm drains lead straight to streams, lakes, or marine waters — whatever goes into your storm drain can end up untreated in our local waters.


Nutrients are essential elements that living organisms need to live, grow, and reproduce. They are naturally occurring in our surrounding environment but can be harmful to plants, animals, and water quality when introduced to the environment in excessive quantities.


Bacteria are microscopic, unicellular organisms that are found in almost every type of environment on Earth. The presence of fecal coliform bacteria indicates that there are feces from a warm-blooded animal contaminating the water.

Aquatic Invasive Species

Aquatic Invasive Species are non-native plants, animals, and pathogens that live primarily in water, thrive in new environments, and are capable of causing economic loss, environmental damage, and harm to human health.

Heavy Metals

High concentrations of heavy metals can kill fish and aquatic plant life and create human health concerns.


Some hydrocarbon pollutants can result in negative health impacts to humans and wildlife. Most petroleum hydrocarbon pollutants are transported by stormwater runoff, which washes the contaminants from roads, driveways, and parking lots into the nearest storm drain or stream.

Photo by J. Gardner, 2015


Pesticides are substances that are intended to prevent, destroy, repel, or mitigate pests. When pesticides end up in our lakes and streams, they can threaten aquatic life and impact our drinking water quality.

Climate Change

Climate change refers to changes in long-term trends in the average climate due to natural variability or as a result of human activity, such as changes in average temperatures and precipitation.