Nitrate in Oregon well water
In Oregon, 17% of 2,606 tested private well samples exceeded the EPA limit for nitrate (10 mg/L).
Nitrate reaches wells from fertilizer, septic systems and manure. Above the limit it can cause methemoglobinemia (blue baby syndrome) in infants under six months, and long-term exposure is associated with some cancers. Shallow and dug wells near farmland or dense septic systems are most at risk.
Check your nitrate number
Type the value from your lab report. It is compared to the EPA limit, the same way the full interpretation does it.
Test your Oregon well for nitrate
Certified lab analysis of your own tap water, bottles and prepaid return shipping included. The Essential well panel covers arsenic, uranium, nitrate, lead, copper, manganese, iron, sodium and bacteria; radon and PFAS are add-ons.
Order the Tap Score well water test kit, from $209Already tested? Upload the report
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Systems that remove nitrate
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Some links below are affiliate links. If you buy through one, the merchant pays us a commission at no extra cost to you. It does not change which products we list or what the data says.
For nitrate
Under-sink reverse osmosis system
under-sink or countertop, about $300
Look for NSF/ANSI 58 certification listing the contaminant you need removed.
For nitrate
Aquasana SmartFlow reverse osmosis
under-sink or countertop, about $225
Certified to NSF/ANSI 58 and 53 to reduce arsenic (96%, pentavalent), fluoride (90%), lead (99%), nitrate, nitrite and PFOA/PFOS at the kitchen tap, with a remineralizer.
Rather have it installed and sized for your well? Book a free in-home water test with a licensed local company.
Where to get a well tested for nitrate in Oregon: certified labs, state programs and prices.
By county, from individual samples
Public monitoring samples against the EPA limit (10 mg/L); counties with at least 30 samples.
| County | Above EPA limit | Samples | Detected | Median | Highest |
|---|---|---|---|---|---|
| Malheur | 452 | 100% | 13 | 74 mg/L | |
| Marion | 96 | 77% | 1.21 | 115 mg/L | |
| Umatilla | 216 | 67% | 0.331 | 68.7 mg/L | |
| Multnomah | 191 | 100% | 5.3 | 54.5 mg/L | |
| Linn | 151 | 87% | 0.61 | 79.7 mg/L | |
| Jackson | 159 | 99% | 0.2 | 43 mg/L | |
| Deschutes | 320 | 73% | 0.26 | 215 mg/L | |
| Morrow | 60 | 88% | 0.241 | 12.9 mg/L | |
| Clackamas | 127 | 65% | 0.09 | 48.7 mg/L | |
| Harney | 115 | 74% | 0.33 | 25 mg/L | |
| Polk | 61 | 64% | 0.26 | 11 mg/L | |
| Washington | 101 | 33% | 0 | 23.9 mg/L | |
| Columbia | 51 | 100% | 0.16 | 1.3 mg/L | |
| Josephine | 50 | 100% | 0.09 | 4.4 mg/L | |
| Douglas | 174 | 90% | 0.06 | 5 mg/L |
- Dead Ox Flat CCD, Malheur County83% of 64
- Ontario CCD, Malheur County74% of 196
- Malheur Junction CCD, Malheur County70% of 63
- Jefferson CCD, Marion County29% of 56
- Hermiston-Umatilla CCD, Umatilla County27% of 81
- Portland East CCD, Multnomah County17% of 161
- Medford CCD, Jackson County17% of 54
- Owyhee CCD, Malheur County16% of 32
- Vale CCD, Malheur County15% of 54
- Albany CCD, Linn County9% of 82
- Sisters-Millican CCD, Deschutes County8% of 263
- Umatilla Reservation CCD, Umatilla County7% of 88
- Boardman CCD, Morrow County4% of 51
- Drewsey CCD, Harney County4% of 56
- Monmouth-Independence CCD, Polk County3% of 32
- Beaverton-Hillsboro CCD, Washington County2% of 55
- Scappoose CCD, Columbia County0% of 51
- Gresham CCD, Multnomah County0% of 30
- Bend CCD, Deschutes County0% of 31
- Kellogg-Yoncalla CCD, Douglas County0% of 32
Sources
- Individual samples from the USGS Water Quality Portal and state monitoring, summarized per geography. nitrate counts and shares are listed on each county and town page with their sources.
Analysis: Nitrate in private wells, decade by decade, from the same public records.