New maps chart nitrate levels in Lower Umatilla Basin Groundwater Management Area wells; more households need testing  

PORTLAND, Ore._Oregon Health Authority (OHA) has launched new maps that show nitrate levels found in domestic well water in parts of Morrow and Umatilla counties known as the Lower Umatilla Basin Groundwater Basin Management Area (LUBGWMA). The information will help residents and local partner organizations track progress toward making sure families in the area that rely on domestic wells for drinking and cooking have safe water. 

“It is encouraging that more than 1,700 households in the LUBGWMA have accessed free well water testing, but we hope many more residents will test their wells and make sure their family’s drinking water is safe. As the maps show, nitrate levels can vary greatly even within a small area. The only way to know is to request a free laboratory test,” said Gabriela Goldfarb, OHA Environmental Public Health section manager. 

The maps show the locations where residents have agreed to have their well water tested in response to an intensive education and outreach campaign over the last 15 months. OHA, along with Oregon Department of Human Services, Morrow County Public Health Department and Umatilla County Health Department, in partnership with several community based organizations, are providing free well tests, free water delivery and, where effective, free reverse-osmosis filtration systems to domestic well users exposed to high levels of nitrate in their well water. 

The LUBGWMA spans northern Morrow County and northwestern Umatilla County and was designated by the state due to high nitrate in groundwater that supplies domestic wells. 

Nitrate in well water is a potential health hazard, and nitrate levels above 10 milligrams per liter (mg/L) are considered dangerous for human consumption. Pregnant people and babies face the greatest risk.  

Residents are encouraged to continue testing their domestic wells’ nitrate levels. OHA recently announced a retesting effort to ensure that households near the 10 mg/L limit are monitored. 

Households with a nitrate test result above 10 mg/L are eligible for free water delivery. For households whose well water tests higher than 10 mg/L but below 25 mg/L, the state will also provide free installation and maintenance of one in-home reverse-osmosis system at their kitchen tap. OHA requires its vendors to install and maintain systems that are certified to reduce nitrate levels to safe for drinking. There are no kitchen-tap treatment systems certified to remove nitrate at levels above 25 mg/L. 

The new maps documenting nitrate levels will be updated monthly with new data. 

To learn more, contact [email protected], or call 541-952-9254 and visit testmywell.oregon.gov to learn about free safe water services for residents of northern Morrow County and northwestern Umatilla County. 

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