Is Mendocino, CA Tap Water Safe? Quality & Contaminants

What was found in Mendocino'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
Nitrate	3164 µg/L 32% of the EPA limit 10000 µg/L Highest in the city: SHORELANDS ROAD & WATER COMPANY · 78 people · 2019	4/6	SYR4
Fluoride	120 µg/L 3% of the EPA limit 4000 µg/L Main supplier: SURFWOOD MUTUAL WATER CORPORATION · 160 people · 2015 Highest in the city: 268 µg/L — HILLS RANCH MUTUAL WATER COMPANY · 79 people · 2019	4/6	SYR4
Total Haloacetic Acids (HAA5)	166 µg/L 277% of the EPA limit, at the 95th percentile of samples — 60 µg/L Main supplier: SURFWOOD MUTUAL WATER CORPORATION · 160 people · 2019	6/6	SYR4
TTHM	143 µg/L 179% of the EPA limit, at the 95th percentile of samples — 80 µg/L Main supplier: SURFWOOD MUTUAL WATER CORPORATION · 160 people · 2019	6/6	SYR4
Copper	120 µg/L 9.2% of the EPA limit 1300 µg/L Highest in the city: POINT OF VIEW MUTUAL WATER CO · 56 people · 2017	2/6	SYR4
Trichloroacetic Acid	118 µg/L No EPA limit set Main supplier: SURFWOOD MUTUAL WATER CORPORATION · 160 people · 2019	1/6	SYR4
Chloroform	114 µg/L No EPA limit set Main supplier: SURFWOOD MUTUAL WATER CORPORATION · 160 people · 2019	2/6	SYR4
Chromium	110 µg/L 110% of the EPA limit, at the 95th percentile of samples — 100 µg/L Highest in the city: HILLS RANCH MUTUAL WATER COMPANY · 79 people · 2019	1/6	SYR4
Bromoform	2 µg/L No EPA limit set Main supplier: SURFWOOD MUTUAL WATER CORPORATION · 160 people · 2019 Highest in the city: 53.9205 µg/L — HILLS RANCH MUTUAL WATER COMPANY · 79 people · 2017	6/6	SYR4
Dichloroacetic Acid	50.65 µg/L No EPA limit set Main supplier: SURFWOOD MUTUAL WATER CORPORATION · 160 people · 2019	2/6	SYR4
Bromodichloromethane	34.7 µg/L No EPA limit set Main supplier: SURFWOOD MUTUAL WATER CORPORATION · 160 people · 2019	4/6	SYR4
Barium	22.85 µg/L 1.1% of the EPA limit 2000 µg/L Main supplier: SURFWOOD MUTUAL WATER CORPORATION · 160 people · 2015	1/6	SYR4
Dibromochloromethane	18.4 µg/L No EPA limit set Main supplier: SURFWOOD MUTUAL WATER CORPORATION · 160 people · 2019	6/6	SYR4
Dibromoacetic Acid	4.61 µg/L No EPA limit set Main supplier: SURFWOOD MUTUAL WATER CORPORATION · 160 people · 2019 Highest in the city: 8.84 µg/L — HILLS RANCH MUTUAL WATER COMPANY · 79 people · 2017	6/6	SYR4
Monochloroacetic Acid	7.04 µg/L No EPA limit set Main supplier: SURFWOOD MUTUAL WATER CORPORATION · 160 people · 2019	1/6	SYR4
Monobromoacetic Acid	1.29 µg/L No EPA limit set Main supplier: SURFWOOD MUTUAL WATER CORPORATION · 160 people · 2019	1/6	SYR4
Lead	0.0069 mg/L 46% of the EPA limit 0.0150 mg/L Main supplier: SURFWOOD MUTUAL WATER CORPORATION · 160 people · 2024 Highest in the city: 0.0160 mg/L — HILLS RANCH MUTUAL WATER COMPANY · 79 people · 2025	6/6	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 Mendocino

Supplier	Population served
SURFWOOD MUTUAL WATER CORPORATION	160
HILLS RANCH MUTUAL WATER COMPANY	79
SHORELANDS ROAD & WATER COMPANY	78
POINT OF VIEW MUTUAL WATER CO	56
SEAFAIR ROAD AND WATER COMPANY	50
BIG RIVER VISTA MUTUAL WATER COMPANY	36

Frequently asked questions about Mendocino tap water

Is Mendocino tap water safe to drink?

EPA testing detected 17 contaminants in the water serving Mendocino. 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 Mendocino?

6 public water suppliers report drinking-water monitoring for Mendocino, California to the EPA. Each is listed above with its population served.

What contaminants are in Mendocino's water?

The contaminants EPA monitoring detected in Mendocino include Nitrate, Fluoride, Total Haloacetic Acids (HAA5), TTHM, Copper. 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.