Septic systems

About 650 permitted septic systems (or on-site sewage systems (OSS)) are located in the Lake Whatcom watershed. Proper care and maintenance of your septic system is critical for the protection of our water quality.


A failing septic system can impact more than just your wallet, it can:

  • Allow potentially harmful bacteria and other disease-causing microorganisms to enter our drinking water
  • Result in greater algae and plant growth in the lake as a result of added nutrients
  • Result in decreased dissolved oxygen in the lake
  • Result in people coming into direct contact with raw sewage

Care and Maintenance

Avoid septic system failure through regular care and maintenance.

  • Get your septic system inspected and pumped every 3-5 years (or when the total amount of solids in the tank equals 1/3 of the total volume)
  • Avoid overloading your septic system:
    • Check your sinks, toilets, and showers regularly for leaks
    • Run your dishwasher, washing machine, and showers at different times
    • Have a break in between running loads of washing
    • Redirect surface water runoff away from the drain field
  • Be aware of what is going down the drain and entering your system:
    • Avoid using your garbage disposal as it may mean your system needs to be pumped more regularly
    • Avoid flushing products designed to kill bacteria down your drain/toilet as these may also kill the essential bacteria needed to make your septic system work properly (antibiotics, products containing bleach, polishes, caustic drain openers)
    • Use cleaning products that are safe for septic systems (OSS)
  • Keep grease and oils out of your drains
  • Avoid using any products containing phosphates or nitrates as these may enter the water supply
  • Flush only human waste and toilet paper down the toilet

Septic System Failure

If you are having a problem with your septic system, you should have it inspected immediately.

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