Arsenic in Oregon well water

In Oregon, 39% of 4,750 tested private well samples exceeded the EPA limit for arsenic (10 ug/L).

Arsenic occurs naturally in New England bedrock and dissolves into well water. Long-term exposure raises the risk of bladder, lung and skin cancers, and is linked to heart disease and lower IQ in children. It has no taste or smell, so testing is the only way to know.

Check your arsenic 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 arsenic

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 $209 Already tested? Upload the report

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Systems that remove arsenic

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For arsenic

Under-sink reverse osmosis system

under-sink or countertop, about $300

Look for NSF/ANSI 58 certification listing the contaminant you need removed.

For arsenic

Whole-house arsenic and uranium filter

whole-house, at the point of entry, about $2,500

Adsorptive iron-based media; sized to your well yield.

For arsenic

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 arsenic in Oregon: certified labs, state programs and prices.

By county, from individual samples

Public monitoring samples against the EPA limit (10 ug/L); counties with at least 30 samples.

County	Above EPA limit	Samples	Detected	Median	Highest
Malheur	93%	1,112	100%	29.7	322 ug/L
Clatsop	62%	39	100%	13	86.2 ug/L
Gilliam	56%	121	100%	10.6	38.8 ug/L
Washington	51%	188	79%	11.5	149 ug/L
Lane	50%	114	88%	10.5	1,260 ug/L
Coos	48%	50	92%	10	50 ug/L
Lake	47%	36	100%	10	32.6 ug/L
Harney	35%	145	99%	6.46	634 ug/L
Benton	33%	45	78%	5	62 ug/L
Multnomah	29%	269	90%	3.9	410 ug/L
Marion	27%	210	93%	6.46	341 ug/L
Lincoln	27%	78	90%	5	63 ug/L
Douglas	20%	248	75%	1	460 ug/L
Yamhill	19%	127	82%	1.47	73.2 ug/L
Morrow	18%	376	100%	7	41 ug/L

Malheur Junction CCD, Malheur County99% of 199
Owyhee CCD, Malheur County99% of 85
Vale CCD, Malheur County99% of 170
Ontario CCD, Malheur County98% of 373
Nyssa CCD, Malheur County88% of 74
Forest Grove-Cornelius CCD, Washington County78% of 41
Astoria CCD, Clatsop County73% of 30
Dead Ox Flat CCD, Malheur County72% of 174
Arlington CCD, Gilliam County57% of 120
Lakeview CCD, Lake County49% of 35
Beaverton-Hillsboro CCD, Washington County46% of 106
North Benton CCD, Benton County45% of 31
Sutherlin CCD, Douglas County44% of 48
Hubbard CCD, Marion County41% of 99
Diamond CCD, Harney County41% of 73
Drewsey CCD, Harney County35% of 60
Portland East CCD, Multnomah County30% of 243
McMinnville CCD, Yamhill County26% of 38
Waldport CCD, Lincoln County24% of 33
Newberg CCD, Yamhill County23% of 31

Sources

Individual samples from the USGS Water Quality Portal and state monitoring, summarized per geography. arsenic counts and shares are listed on each county and town page with their sources.

Analysis: Arsenic in private wells, state by state, from the same public records.