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Upcoming Groundwater Advisory Committee Meetings:

  • October 15, 2015 5:00 PM
    Location: Radio KDNA,121 Sunnyside Ave, Granger, WA 98932


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Lower Yakima Valley Groundwater Management Area FAQ

What is the goal of the GWMA?

The goal of the Lower Yakima Valley GWMA is to reduce nitrate contamination concentrations in groundwater below state drinking water standards. The target area extends from Union Gap to County Line Road in Yakima County, Washington, minus the Yakama Nation. View Map.


When was the GWMA formed?

In 2011 the Washington Department of Ecology granted a request by Yakima County to create a special study area and establish an advisory committee to find solutions to prevent contamination and protect residents who might be exposed to high levels of nitrate in their drinking water. The area is known as the Lower Yakima Valley Groundwater Management Area. 2011 Request for Identification Lower Yakima Valley Groundwater Management Area  PDF Document

  • In the short-term, the goal is to educate people about the problem and provide information on how they can protect themselves. 
  • The long-term goal is to reduce nitrate concentrations in groundwater to below state drinking water standards. This will be accomplished by using available and new data collected in the Valley to prevent continued groundwater pollution and make sure residents have clean and safe drinking water.


What is the Lower Yakima Valley Groundwater Advisory Committee (GWAC)?

The GWAC is a multi-agency and citizen-based group that is coordinating the effort to reduce nitrate contamination in the groundwater within the lower Yakima Valley. The GWAC is responsible for developing the GWMA Plan. GWAC Membership.


How often does the GWAC meet?

The full committee meets at least every other month. In addition, the GWAC has organized itself into seven working groups that also meet regularly to develop the GWMA Plan. All meetings are posted on the Web:

Are the meetings open to the public?

Yes. The public is welcome to attend both the full GWAC committee meetings and working group meetings. Check out the next meeting.


Nitrate Education – Q&A

What is nitrate?

Nitrate is a chemical found in fertilizers, manure and septic tank liquids. Rain or irrigation water can carry nitrate down through the soil into groundwater. Your drinking water may contain nitrate if your well draws from this groundwater.


Who is considered a high public health risk from nitrate?

Children less than 12 months of age, pregnant women, or individuals susceptible to health problems from nitrate (as documented by their healthcare provider).


Why are pregnant women, infants and others at high public risk?

Nitrate is a potential human health threat especially to infants, causing the condition known as methemoglobinemia, also called "blue baby syndrome." Nitrate is taken in by eating food and drinking water. Nitrate is converted in the gut to nitrite, which then combines with hemoglobin to form methemoglobin, thus decreasing the ability of the blood to carry oxygen. Infants are more susceptible to nitrate toxicity than older children or adults. Fatalities are rare, but sub-acute methemoglo binemia can be limiting or asymptotic to an infant’s development, making the condition particularly harmful and permanently debilitating. Chronic consumption of high levels of nitrate may also cause other health problems for those who have low resistance to infection.

For more information about nitrate, please read the Washington State Department Of Nitrate in Drinking Water Publication


Water Quality Testing – Q&A

Why should I test my water?

If you are on a private shallow well and have a household member considered a high public health risk, it is a good idea to test your water for nitrate.  It is a colorless, odorless, and tasteless chemical that is only detectable by chemical testing.  It is also a good idea to test for coliform.

Aren’t water supplies tested and treated to be safe?

Public water systems must meet minimum water quality standards to be considered safe and reliable.  A water system can include those of a city and town, down to a small home owners’ association or commercial business. These systems must test their wells on a regular basis to show they meet the minimum standards.  Or if necessary install treatment if the samples show the water supply is contaminated.

Many residents, however, rely on private or shared drinking water wells that are not regulated.   These residents are responsible for testing their own well to make sure it is safe to drink.  They can best protect themselves by having samples analyzed from their drinking water wells by a certified lab at least once a year for bacteria and nitrate.


How do I have my water tested?

Contact a certified testing laboratory for more information. The testing laboratory will provide you with the water bottle and instructions to properly test your water.


Where do I go to get my water tested?

After obtaining a water sample as directed by the certified lab, you will return the sample to the lab for analysis.


How much does the water test cost?

The water test for nitrate and coliform costs roughly $60 (as of February 2014).


What do my test results mean?

Nitrate results above 10 parts per million is above the Maximum Contaminant Level (MCL) and is considered a hazard.


What should I do if I find out my water isn’t safe to drink?

You or your landlord may want to seek treatment or alternative water sources for drinking and cooking, based on the results of these tests.  For instance, a treatment solution for bacteria may not work for nitrate.  You may wish to rely on bottled water, especially for mixing baby formula and for younger family members or for pregnant women. Or you may install a certified filtration system that eliminates nitrate, bacteria, or both types of contamination.

If you are concerned that your water was the cause for someone being sick, you should see a doctor.  For bacterial contamination, symptoms can seem flu-like, but the drinking water may be the problem.


Where can I get more information?

If you get your drinking water from a private well and are located within the Lower Yakima Valley (outside of the Yakama Nation) and would like to get your well tested, contact:

  • The Yakima Health District Help Desk at: 509-249-6508

On the Yakama Nation, contact:

  • Indian Health Services -Environmental Health - Shawn Blackshear 509-865-1776
If you get your water from a public water system, call your water utility or:

  • The Washington State Department of Health, Office of Drinking Water at

1-800-521-0323 or visit us online at:
For a list of certified labs, go to certified testing laboratory or:

For more information about private wells, please read: