Copper in Oregon Drinking Water
Ranked by 90th percentile copper level (mg/L) · Data from EPA SDWIS & UCMR
Copper in Oregon: what the data shows
Oregon has 75 cities with copper monitoring data. The state average 90th percentile copper level is 1.850 mg/L, compared to 28.808 mg/L nationally — better than the national average. 75 cities exceed the EPA action level of 1.3 mg/L. Copper in drinking water typically comes from corrosion of copper pipes and plumbing fixtures, particularly in older homes. The EPA action level of 1.3 mg/L is the 90th percentile threshold — if more than 10% of tap samples exceed it, utilities must take corrective action including adjusting water chemistry to reduce corrosivity. Short-term copper exposure above the action level can cause gastrointestinal distress. Long-term exposure at elevated levels is associated with liver and kidney damage. Flushing your tap for 30 seconds before use and using an NSF 53-certified filter can reduce copper exposure.
Cities exceeding 1.3 mg/L EPA Action Level
Copper data across Oregon
Each dot is a city, colored by overall water quality grade. Cities with copper levels above the 1.3 mg/L EPA action level are highlighted. Size reflects population served.
Top 10 cities by copper level in Oregon
Highest Copper levels (mg/L)
All Oregon cities ranked by copper level
| # | City | Level | Level | Exceeds? | Violations | Grade |
|---|---|---|---|---|---|---|
| 1 | Cottage Grove | 3.840 mg/L | Yes | 173 | F | |
| 2 | Seaside | 3.300 mg/L | Yes | 27 | F | |
| 3 | Cave Junction | 3.300 mg/L | Yes | 60 | D | |
| 4 | Lyons | 3.200 mg/L | Yes | 8 | F | |
| 5 | Milwaukie | 3.120 mg/L | Yes | 1 | F | |
| 6 | Manzanita | 3.030 mg/L | Yes | 4 | B | |
| 7 | Garibaldi | 2.700 mg/L | Yes | 15 | C | |
| 8 | Newport | 2.630 mg/L | Yes | 29 | F | |
| 9 | Antelope | 2.308 mg/L | Yes | 25 | C- | |
| 10 | Falls City | 2.218 mg/L | Yes | 3 | B- | |
| 11 | Bandon | 2.190 mg/L | Yes | 119 | F | |
| 12 | Gaston | 2.190 mg/L | Yes | 13 | D | |
| 13 | Sandy | 2.180 mg/L | Yes | 161 | F | |
| 14 | Canby | 2.150 mg/L | Yes | 21 | D | |
| 15 | Nyssa | 2.110 mg/L | Yes | 34 | B- | |
| 16 | Carlton | 2.100 mg/L | Yes | 9 | B- | |
| 17 | Otis | 2.072 mg/L | Yes | 28 | D | |
| 18 | Rogue River | 2.050 mg/L | Yes | 7 | C | |
| 19 | Coquille | 2.020 mg/L | Yes | 57 | F | |
| 20 | Waldport | 2.004 mg/L | Yes | 25 | D | |
| 21 | Cloverdale | 2.000 mg/L | Yes | 5 | F | |
| 22 | Cornelius | 1.990 mg/L | Yes | 5 | F | |
| 23 | Lafayette | 1.950 mg/L | Yes | 16 | C- | |
| 24 | Brookings | 1.930 mg/L | Yes | 19 | D | |
| 25 | Gresham | 1.920 mg/L | Yes | 0 | B | |
| 26 | Newberg | 1.920 mg/L | Yes | 270 | F | |
| 27 | Grants Pass | 1.900 mg/L | Yes | 78 | F | |
| 28 | Monmouth | 1.870 mg/L | Yes | 18 | D | |
| 29 | The Dalles | 1.860 mg/L | Yes | 54 | F | |
| 30 | Port Orford | 1.860 mg/L | Yes | 24 | D | |
| 31 | Rickreall | 1.858 mg/L | Yes | 15 | F | |
| 32 | Molalla | 1.800 mg/L | Yes | 75 | F | |
| 33 | Hillsboro | 1.790 mg/L | Yes | 7 | F | |
| 34 | Glendale | 1.750 mg/L | Yes | 42 | B | |
| 35 | Corvallis | 1.740 mg/L | Yes | 38 | F | |
| 36 | St Helens | 1.730 mg/L | Yes | 33 | F | |
| 37 | Rainier | 1.720 mg/L | Yes | 121 | D | |
| 38 | Albany | 1.713 mg/L | Yes | 35 | F | |
| 39 | Brownsville | 1.700 mg/L | Yes | 17 | F | |
| 40 | Salem | 1.680 mg/L | Yes | 108 | F | |
| 41 | Springfield | 1.640 mg/L | Yes | 19 | F | |
| 42 | Gold Beach | 1.640 mg/L | Yes | 3 | F | |
| 43 | Yamhill | 1.610 mg/L | Yes | 53 | F | |
| 44 | Scappoose | 1.600 mg/L | Yes | 84 | F | |
| 45 | Gleneden Beach | 1.590 mg/L | Yes | 2 | A- | |
| 46 | Stayton | 1.584 mg/L | Yes | 2 | B+ | |
| 47 | West Linn | 1.570 mg/L | Yes | 15 | F | |
| 48 | Tangent | 1.565 mg/L | Yes | 7 | C | |
| 49 | Lebanon | 1.560 mg/L | Yes | 16 | F | |
| 50 | Prairie City | 1.516 mg/L | Yes | 6 | B- | |
| 51 | Columbia City | 1.500 mg/L | Yes | 3 | B | |
| 52 | Mulino | 1.500 mg/L | Yes | 10 | F | |
| 53 | Nehalem | 1.480 mg/L | Yes | 8 | D | |
| 54 | Prineville | 1.460 mg/L | Yes | 56 | F | |
| 55 | Hubbard | 1.455 mg/L | Yes | 30 | F | |
| 56 | Astoria | 1.450 mg/L | Yes | 45 | F | |
| 57 | Independence | 1.450 mg/L | Yes | 6 | B | |
| 58 | Junction City | 1.450 mg/L | Yes | 14 | F | |
| 59 | Siletz | 1.446 mg/L | Yes | 9 | B+ | |
| 60 | Eugene | 1.440 mg/L | Yes | 178 | F | |
| 61 | Bay City | 1.420 mg/L | Yes | 3 | B | |
| 62 | Amity | 1.412 mg/L | Yes | 31 | D | |
| 63 | Beaverton | 1.410 mg/L | Yes | 10 | F | |
| 64 | Ophir | 1.410 mg/L | Yes | 2 | B- | |
| 65 | Oregon City | 1.400 mg/L | Yes | 14 | D | |
| 66 | Cascade Locks | 1.400 mg/L | Yes | 3 | C | |
| 67 | Mount Vernon | 1.400 mg/L | Yes | 3 | B+ | |
| 68 | Pacific City | 1.395 mg/L | Yes | 2 | D | |
| 69 | Estacada | 1.390 mg/L | Yes | 119 | F | |
| 70 | Yachats | 1.390 mg/L | Yes | 5 | D | |
| 71 | Portland | 1.370 mg/L | Yes | 118 | F | |
| 72 | Talent | 1.370 mg/L | Yes | 3 | B- | |
| 73 | Welches | 1.360 mg/L | Yes | 47 | D+ | |
| 74 | Harbor | 1.359 mg/L | Yes | 3 | B+ | |
| 75 | Tillamook | 1.350 mg/L | Yes | 38 | F |
Frequently asked questions about copper in Oregon
Is copper in Oregon drinking water safe?
75 cities in Oregon exceed the EPA action level of 1.3 mg/L for copper. The state average is 1.850 mg/L. Copper levels are highest in homes with copper plumbing, particularly when water sits in pipes overnight. Flushing the tap before use significantly reduces copper in drinking water.
What causes high copper levels in Oregon tap water?
Copper typically leaches from copper pipes and brass fittings within homes, not from the water source itself. Corrosive (low pH or soft) water accelerates this leaching. Water utilities with high copper readings are required to adjust water chemistry to reduce corrosivity. You can reduce exposure by flushing your tap for 30 seconds before use.