Safe and reliable drinking water keeps us healthy. In Washington State, 88 percent of us get our water from public water systems.
Why is data about contaminants in drinking water important?
- If present in drinking water, nitrate can impair our blood's ability to transport oxygen. Nitrate contamination of drinking water can come from the agricultural use of fertilizers and manure, septic tank and waste water effluent, and the disposal of animal wastes.
- Less than 0.5% of our public water systems have reported nitrate levels above the federal limit of 10 mg/L.
- If present in drinking water, synthetic organic compounds (SOCs) such as Atrazine and Di [2-ethylhexyl] phthalate (DEPH), and volatile organic compounds (VOCs) such as tetrachloroethene, also called perchloroethylene (PCE), and trichloroethylenes (TCE) can cause a long-term potential health risk.
- In Washington State these compounds rarely occur in our drinking water and all community water systems that were tested met the standard.
- Haloacetic acids (HAA5) are disinfection by-products (DBPs) formed when chlorine is used to disinfect water. HAA5 can vary seasonally and are generally tested every quarter on water systems where disinfection is necessary. If present in drinking water, DBPs can cause a long-term potential health risk.
- About 0.8% of tested systems test above the maximum contaminant level of 60 µg/L.
View the Data
For information or questions related to the Washington Tracking Network, email DOH.WTN@doh.wa.gov.
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