Drinking Water Program

Interesting facts and commonly asked questions about public water systems:

• There are 2,758 public water systems in Oregon

• 3 million+ Oregonians are served by public systems

• 2,426 systems rely on groundwater alone

• 87% of systems serve less than 500 people each

• 400,000 people in Oregon are on individual private wells

• 93% of Oregonians receive water that meets all EPA standards (99% in Deschutes County)

Where does my drinking water come from?

Drinking water comes from surface and ground water sources. Surface sources include rivers, lakes or reservoirs and ground water sources are usually drilled wells. Smaller water systems tend to use wells while large systems like cities often rely on surface sources to supplement well supplies.

When surface water is used for drinking water, it must be filtered and disinfected before use. Public water systems using surface water are required to frequently monitor the water for contaminants in addition to the necessary treatment. Very few public systems in Deschutes County use surface water.

Locally, one common source for private drinking water is from cisterns. Cisterns are large tanks (usually made of concrete) for storing water. If the cistern is filled by a water hauler from an approved source it is generally considered safe. However, if the cistern is filled from a nearby irrigation canal it is not! Canal water is a surface source and is potentially contaminated with pathogenic microorganisms and/or chemicals. If you currently use irrigation water for human consumption, you should contact your irrigation district and review the Well and Cistern Disinfection information.

Wells are another common source of domestic water.  If you are concerned about the quality of your well water, you may want to have your water tested.  It is recommended that private wells are tested for coliform bacteria either quarterly or bi-annually and nitrate annually.

Deschutes County does not have laboratory facilities and cannot test water.  There are, however, two certified labs in the area that can test for any water constituents.

Pyxis Laboratories  -  Redmond: 548-0972

Umpqua Research  -  Bend: 312-9454

Box R Labs - Prineville: 447-4911

Homeowners can collect samples themselves or have the lab collect samples for them.  If you collect samples yourself, special sample bottles are needed and are available from the lab.  Special sampling techniques should also be followed to ensure an accurate result.

Who samples my water and what do they look for?

Federal law requires public water systems to take routine water samples and report the results to the state. The type of contaminant tested for and the sampling frequency depends on the size of the system. Typically, public community systems sample for the presence of bacteria every month, nitrates every year and a variety of chemicals every 3 years. Only certified laboratories can analyze and interpret samples.

Local governments, such as Deschutes County, monitor public water systems and ensure the required samples are being taken and reported. Failure to properly sample and report on water quality can result in fines and/or closure of any facilities served by the system.

Households served by private wells are not required to do routine sampling, but it is recommended that water is tested for bacteria quarterly or bi-annually and nitrates once per year. Ultimately, it is the homeowner’s responsibility to maintain the quality of the drinking water.

How can I protect my private water supply?

The best way to prevent contamination of your well is to carefully manage the activities around the water source.

* Make sure septic systems are at least 100’ from the well

* Store fuels and chemicals away from the wellhead

* Periodically inspect the wellhead and check for cracks or gaps in the seal

* Ensure surface runoff drains away from the well casing

* Hire a licensed well driller for any modifications or alterations to the well

* Keep the area around the wellhead clean