How does a city test the quality of their drinking water? Get de - NBC Right Now/KNDO/KNDU Tri-Cities, Yakima, WA |

How does a city test the quality of their drinking water? Get details from Yakima officials

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LabTest Business Sign LabTest Business Sign
Clean water vs. water with coliform (yellow) Clean water vs. water with coliform (yellow)
Water with E. coli contamination (neon white) Water with E. coli contamination (neon white)

Yakima, WA - With the City of Mabton recently having to deal with contaminated drinking water it makes people wonder, how is drinking water actually tested? The City of Yakima's Water Irrigation Manager and a lab technician with LabTest, a local environmental testing facility, help explain the process.

Dave Brown, the city's water irrigation manager, says Yakima's main water source comes from the Naches River, along with ground water wells. Based on standards set by Washington State Health Department, the frequency of Yakima's and any city's drinking water testing is based on the population size. 

"Its all based on the population, so our population says we have to take 80 samples a month, that's about 20 samples a week, we take them all over town. Then we have a plan called the coliform monitoring plan, which prescribes where we take them, we take them all over the city that's representative of the water all over town," said Brown.

Coliform bacteria are organisms that are present in the environment and in the feces of all warm-blooded animals and humans. Their presence in drinking water indicates that disease-causing organisms, or pathogens, could be in the water system. Most pathogens that can contaminate water supplies come from the feces of humans or animals, according to the Washington State Health Department's website.

The City of Yakima works with Cascade Analytical Lab for all kinds of testing of city water.  Another lab local to Yakima is, LabTest, and they test water, soil, and wine, for all kinds of environmental contaminants.  LabTest provides water testing services for the city of Toppenish, Harrah, and more.

Testing for coliform is the most common drinking water tests done at these labs.

"We take samples of water, and put them in an incubator for a 24-hour period, if the water comes back yellow, the water sample is positive for coliform, to find out if there is E. coli present in the water, we turn off the lights, put a black light up to the water and if it turns a neon white color, E. coli is present," said Giles Hamilton, Lab Supervisor at LabTest.

If coliform bacteria are found in a water sample, water system operators work to find the source of contamination and restore safe drinking water. 

Labs also test for metals in the water as well, but those tests do not happen as frequent as coliform testing.

For more information on LabTest and/or to inquire about getting your water tested with them, click here.