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Tap water quality report

North Marin Water District

EPA monitoring tested this supplier for 93 contaminants and detected 14. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

93
contaminants tested
14
detected
61,691
people served
2
health-based violations
California rankingsLead in CaliforniaPFAS in California
Water source
Surface water
Ownership
Local government
Counties served
Marin

Compliance record

Formal violations the EPA has on file for this supplier. A health-based violation means a contaminant limit or a required treatment was breached; the rest are monitoring or reporting failures — still violations, but not a measured health risk.

2
health-based violations
2
violations on file
0
still open
ViolationTypeStatusPeriod
MCL Health-based Resolved 1993-07-01 → 1993-08-31
MCL Health-based Resolved 1993-07-01 → 1993-08-31

Other contaminants detected

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 single worst sample on record — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately.
ContaminantLevel vs EPA limitDetection rateSourcePeriod
TTHM
97.67 µg/L 122%
of the EPA limit, in the worst sample — 80 µg/L
 307/311 SYR4 2012–2019
Bromodichloromethane
29.04 µg/L
No EPA limit set
 306/311 SYR4 2012–2019
Total Haloacetic Acids (HAA5)
36.1 µg/L 60%
of the EPA limit 60 µg/L
 306/311 SYR4 2012–2019
Chloroform
58.11 µg/L
No EPA limit set
 305/311 SYR4 2012–2019
Dichloroacetic Acid
15.6 µg/L
No EPA limit set
 302/311 SYR4 2012–2019
Dibromochloromethane
9.52 µg/L
No EPA limit set
 296/311 SYR4 2012–2019
Trichloroacetic Acid
26.8 µg/L
No EPA limit set
 277/311 SYR4 2012–2019
Dibromoacetic Acid
3.7 µg/L
No EPA limit set
 152/311 SYR4 2012–2019
Bromoform
3.05 µg/L
No EPA limit set
 143/311 SYR4 2012–2019
Lead
0.0 mg/L 0%
of the EPA limit 0.0150 mg/L
 26/26 LCR 2023
Fluoride
157 µg/L 3.9%
of the EPA limit 4000 µg/L
 13/13 SYR4 2012–2019
Arsenic
6.8 µg/L 68%
of the EPA limit 10 µg/L
 7/17 SYR4 2012–2019
Nitrite
0.0680 µg/L 0%
of the EPA limit 1000 µg/L
 2/8 SYR4 2012–2018
Monochloroacetic Acid
6.7 µg/L
No EPA limit set
 1/311 SYR4 2012–2019
79 contaminants tested, none detected
1,1,1-Trichloroethane1,1,2-Trichloroethane1,1-Dichloroethylene1,2,4-Trichlorobenzene1,2-DIBROMO-3-CHLOROPROPANE1,2-Dichloroethane1,2-Dichloropropane11Cl-PF3OUdS2,4,5-TP2,4-D4:2 Fts6:2 Fts8:2 Fts9Cl-PF3ONSAdonaAntimony, TotalAtrazineBariumBenzeneBeryllium, TotalChlorobenzeneCopperCadmiumCarbofuranCarbon TetrachlorideChromiumDichloromethaneDalaponDinosebDiquatEthylene DibromideEndothallEthylbenzeneGlyphosateHfpo-DaLassoLeadMercuryMonobromoacetic AcidNetfosaaNfdhaNmefosaaNitrateOxamylPfbaPFBSPfdaPfdoaPfeesaPfhpaPfhpsPfhxaPFHXSPfmbaPfmpaPFNAPFOAPFOSPfpeaPfpesPftaPftrdaPfunaPentachlorophenolPicloramSeleniumSimazineStyreneTetrachloroethyleneThallium, TotalTolueneTrichloroethyleneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneLithiumO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact
WILLIAMS, TONY
Phone
415-761-8945
Email
twilliams@nmwd.com

Frequently asked questions about North Marin Water District

Is North Marin Water District tap water safe to drink?

EPA monitoring detected 14 contaminants in North Marin Water District's water. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and the utility's annual Consumer Confidence Report for its official compliance status.

What contaminants were detected in North Marin Water District's water?

EPA monitoring detected TTHM, Bromodichloromethane, Total Haloacetic Acids (HAA5), Chloroform, Dichloroacetic Acid, and others. The full list with the level and data source for each is above.

How many people does North Marin Water District serve?

North Marin Water District reports serving 61,691 people in California, per its EPA record.

Has North Marin Water District had any water quality violations?

The EPA has 2 violations on file for North Marin Water District, of which 2 are health-based (a contaminant limit or required treatment was breached) and 0 remain open. The rest are monitoring or reporting failures.

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.