Is Coos Bay, OR Tap Water Safe? Quality & Contaminants

What was found in Coos Bay's water

The level at the city's main supplier, the highest level anywhere in the city, the EPA limit for each, and where every figure comes from.

Contaminant	Level vs EPA limit	Suppliers	Source
Fluoride	713 µg/L 18% of the EPA limit 4000 µg/L Main supplier: COOS BAY NORTH BEND WTR BRD · 34,500 people · 2019	2/5	SYR4
Nitrate	642 µg/L 6.4% of the EPA limit 10000 µg/L Main supplier: COOS BAY NORTH BEND WTR BRD · 34,500 people · 2019	3/5	SYR4
Nitrate-Nitrite	211 µg/L 2.1% of the EPA limit 10000 µg/L Main supplier: COOS BAY NORTH BEND WTR BRD · 34,500 people · 2019 Highest in the city: 597 µg/L — COUNTRY CLUB ESTATES WD · 45 people · 2019	3/5	SYR4
Copper	86.79 µg/L 6.7% of the EPA limit 1300 µg/L Main supplier: COOS BAY NORTH BEND WTR BRD · 34,500 people · 2019 Highest in the city: 246 µg/L — COUNTRY CLUB ESTATES WD · 45 people · 2019	2/5	SYR4
Total Haloacetic Acids (HAA5)	23.465 µg/L 39% of the EPA limit 60 µg/L Main supplier: COOS BAY NORTH BEND WTR BRD · 34,500 people · 2019 Highest in the city: 180.6 µg/L — COUNTRY CLUB ESTATES WD · 45 people · 2019	3/5	SYR4
TTHM	50.58 µg/L 63% of the EPA limit 80 µg/L Main supplier: COOS BAY NORTH BEND WTR BRD · 34,500 people · 2019 Highest in the city: 89.735 µg/L — COUNTRY CLUB ESTATES WD · 45 people · 2019	3/5	SYR4
Barium	10.7 µg/L 0.5% of the EPA limit 2000 µg/L Main supplier: COOS BAY NORTH BEND WTR BRD · 34,500 people · 2019 Highest in the city: 28.2 µg/L — GARDEN VALLEY WATER ASSOCIATION · 84 people · 2019	3/5	SYR4
Lead	2.69 µg/L 18% of the EPA limit 15 µg/L Main supplier: COOS BAY NORTH BEND WTR BRD · 34,500 people · 2019 Highest in the city: 14.465 µg/L — COUNTRY CLUB ESTATES WD · 45 people · 2019	3/5	SYR4
Arsenic	4 µg/L 40% of the EPA limit 10 µg/L Main supplier: COOS BAY NORTH BEND WTR BRD · 34,500 people · 2019	1/5	SYR4
Xylenes, Total	2.51 µg/L 0% of the EPA limit 10000 µg/L Highest in the city: GARDEN VALLEY WATER ASSOCIATION · 84 people · 2019	2/5	SYR4
Combined Radium (-226 And -228)	2.5 pCi/L 50% of the EPA limit 5 pCi/L Main supplier: COOS BAY NORTH BEND WTR BRD · 34,500 people · 2014	1/5	SYR4
Chromium	2 µg/L 2% of the EPA limit 100 µg/L Main supplier: COOS BAY NORTH BEND WTR BRD · 34,500 people · 2019	1/5	SYR4
Selenium	2 µg/L 4% of the EPA limit 50 µg/L Main supplier: COOS BAY NORTH BEND WTR BRD · 34,500 people · 2019	1/5	SYR4
Lead	0.0050 mg/L 33% of the EPA limit 0.0150 mg/L Main supplier: COOS BAY NORTH BEND WTR BRD · 34,500 people · 2023	4/5	LCR

Each bar shows the measured level as a share of the EPA limit: green is well under, amber is close to it, red is over. For lead and copper the limit applies to exactly the 90th-percentile figure shown, so red there means a real exceedance. For everything else the limit applies to a running annual average while the figure is the 95th percentile of the system's samples — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately. These are the utilities' own EPA-reported results, not a city-wide average. A detection means the lab measured the substance — it isn't the same as exceeding a legal limit. Hover a source tag to see the EPA program and years behind each figure.

Water suppliers serving Coos Bay

Supplier	Population served
COOS BAY NORTH BEND WTR BRD	34,500
GARDEN VALLEY WATER ASSOCIATION	84
SUMNER WATER CORPORATION	50
COUNTRY CLUB ESTATES WD	45
WATSONVILLE WATER SYSTEM	27

Frequently asked questions about Coos Bay tap water

Is Coos Bay tap water safe to drink?

EPA testing detected 14 contaminants in the water serving Coos Bay. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.

How many water suppliers serve Coos Bay?

5 public water suppliers report drinking-water monitoring for Coos Bay, Oregon to the EPA. Each is listed above with its population served.

What contaminants are in Coos Bay's water?

The contaminants EPA monitoring detected in Coos Bay include Fluoride, Nitrate, Nitrate-Nitrite, Copper, Total Haloacetic Acids (HAA5). The full list, with the level at the main supplier and the data source, is in the table above.

Where does this data come from?

Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.