Testing drinking water

The Department of Health recommends private well owners test their drinking water every year for coliform bacteria and nitrate.  These two contaminates can rapidly affect a person’s health — possibly even with just one drink of water. In most counties when you sell a home with a private well, the county health or planning department or your lender may require you to provide water sampling results to show that your water is safe to drink. You may also want to test your private well if flooding has occurred in your area.

If you own a private well, you are responsible for testing your own water.  Some counties have water quality testing services available through local health departments and districts. We can help you find an accredited lab to help you test your well water for contaminants.

Find a lab

We regulate well construction in Washington. We also accredit laboratories that test water.

Sampling your well water is easy — just contact an accredited lab. Labs that accept drinking water samples appear as light blue dots on the map below.

Map information is also available in the Lab Search application.

Public water systems

The Washington State Department of Health is in charge of drinking water for larger water systems. Most public water systems have water quality data available to the public. You can request a copy of their consumer confidence report.