Water Supply and Treatment

Where does your drinking water come from?

Lake Whatcom is the drinking water source for over 100,000 people, which is approximately half of all Whatcom County residents. Water is provided by:

Water flows into Lake Whatcom from two main sources:

  • Rainwater that falls in the Lake Whatcom watershed and flows into the lake from pipes, ditches, and streams.
  • Water from the Deming Glacier on Mt. Baker that flows to the Middle Fork of the Nooksack River and is periodically diverted into Lake Whatcom through a diversion and conveyance system.


How does your drinking water get from the lake to your tap?

Drinking water is withdrawn from two major intake structures in the lake.

The City of Bellingham withdraws water from Basin 2 through a 1,200-foot wooden pipeline that leads to Whatcom Falls Park. At the park, the water first flows through a screenhouse then to the treatment plant. The city's treatment plant is capable of producing 24 million gallons of drinking water per day and serves residents of Bellingham as well as five neighboring water districts and one tribal nation.

The Lake Whatcom Water and Sewer District withdraws water out of Basin 3 to serve residents of Sudden Valley, Geneva, and portions of North Shore and South Bay. The District's treatment process is similar to that of the City of Bellingham but uses four multi-media filters and reaches a maximum output of 50,100 gallons per day.

What happens to your wastewater?

Sewers were first installed throughout the developed areas of Bellingham in 1892. These original sewers collected both sewage and rainwater and discharged them into Whatcom Creek and Bellingham Bay. Most of these early sewers are still in use. The ones carrying sewage are now separate from those carrying stormwater and send their flows directly to the wastewater treatment plant.

  • In 1947, the City of Bellingham first provided primary wastewater treatment, discharging effluent into a shallow party of Bellingham Bay from a treatment plant located near the mouth of Whatcom Creek. This site is now the fish hatchery in Maritime Heritage Park.
  • In 1974, Bellingham replaced the Whatcom Creek treatment plant with the Post Point Wastewater Treatment Plant at the foot of Harris Avenue. The Post Point Wastewater Treatment Plant provided primary treatment for up to a peak flow of 55 million gallons per day for the area's sewered population.
  • In 1993, Post Point was upgraded to include secondary treatment at a cost of $55 million. This upgrade to secondary treatment increased contamination removal to 95 percent before releasing wastewater into Bellingham Bay.
  • In 2014, additional plant improvements were completed to increase secondary treatment processes, upgrade to more efficient equipment, and to increase wastewater treatment capacity at the Post Point Plant.
  • The Post Point Plant receives all sewage from both the City of Bellingham and the Lake Whatcom Water and Sewer District.

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