Science & Environment

Environmental regulators to test well water for contaminants in Central Oregon

By Monica Samayoa (OPB)
Nov. 28, 2022 2 p.m. Updated: Nov. 28, 2022 10:48 p.m.

Water samples indicate a growing problem with nitrate and arsenic pollution.

The Oregon Department of Environmental Quality will test the water in up to 100 wells for free in southern Deschutes County as part of a statewide study of groundwater pollution.

The testing will take place in the spring and again in the fall. Similar testing for groundwater contamination has been completed over the last five years in seven other areas around the state, including the Willamette Valley, Harney County and the Klamath Basin.


Southern Deschutes County has many shallow groundwater aquifers, making wells more vulnerable to contamination. The agency will test for nitrate, arsenic, pesticides and other contaminants.

DEQ spokesperson Harry Esteve said the agency will be collecting samples from a mix of private and public wells, as well as wells for irrigation and livestock, to get a better picture of which areas have more contamination. Some wells will be tested twice in spring and fall.

“The area is vulnerable to nitrate contamination from septic systems,” Esteve said. “We picked it because the data does show elevated nitrate levels in some water samples in the kind of shallow and vulnerable aquifers. But we don’t have a ton of data on it.”

DEQ has been testing well water in Deschutes County since the late 1970s, and has detected more nitrate and arsenic pollution in the past decade. In 2014, some wells tested above the above the federal safe drinking water levels for both contaminants.

DEQ to test for contaminants in southern Deschutes county

The Oregon Department of Environmental Quality will test the water for contaminants in up to 100 wells for in the highlighted area of southern Deschutes County.

Oregon Department of Environmental Quality

Drinking nitrate levels exceeding federal standards can cause serious health problems that can lead to respiratory infections, thyroid dysfunction and stomach or bladder cancer. The Oregon Health Authority warns drinking high levels of arsenic could lead to stomach pain, nausea, vomiting, diabetes or reproductive system disorders.


Esteve said the agency has already received many requests for testing in southern Deschutes County but not everyone that has submitted a request will qualify for testing.

“Based on the response, we will probably get more than the 60 to 100 that we want to test,” he said.

Oregon has no water quality regulations on private wells. Homeowners are responsible for testing their wells for contamination and are encouraged to test regularly.

High levels of contamination could lead to a Groundwater Management Area designation, which creates a committee tasked with figuring out what’s causing the high levels of contamination and developing plans to reduce it.

Oregon has three Groundwater Management Areas. The Lower Umatilla Basin Groundwater Management Area, created in 1990, has recently come under scrutiny from local residents and public officials because nitrate levels have actually increased since the creation of the committee, according to data from DEQ. Groundwater is the primary drinking water source for residents in Morrow and Umatilla counties, and it has been polluted for more than 30 years. In June, Morrow County declared a local state of emergency after dozens of private well water tests showed high levels of nitrate contamination. Some wells tested up to five times higher than the federal limit for safe drinking water.

The committee recently restructured to address these concerns and is launching a new effort to reduce nitrate contamination.

Esteve said after DEQ collects the samples, the agency will determine how to move forward.

Residents interested in getting their well water tested can contact the agency through email or by calling 503-693-5736.

Residents can also collect their own well water samples and send them to an accredited lab for results. The price for testing depends on the pollutant and testing kit provided by the lab. Some prices can range from $20 to $45 per pollutant.

Correction: In an earlier version of this article, a DEQ official misstated information about the characteristics of the area where well testing is being conducted. The story has been updated to reflect that the area is vulnerable to nitrate contamination from septic systems.