Compliance record
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 95th percentile of this
system's samples — over 100% is worth reading, but is not by itself a
violation. Where a single sample came in higher than that percentile, it
is noted under the bar. Formal violations are listed separately.
| Contaminant | Level vs EPA limit | Detection rate | Source | Period |
|---|---|---|---|---|
| Bromodichloromethane | 13.676 µg/L No EPA limit set
worst single sample: 16.2 µg/L | 327/327 | SYR4 | 2012–2019 |
| Chloroform | 41.214 µg/L No EPA limit set
worst single sample: 68.4 µg/L | 327/327 | SYR4 | 2012–2019 |
| Dibromochloromethane | 5.5 µg/L No EPA limit set
worst single sample: 10.8 µg/L | 326/327 | SYR4 | 2012–2019 |
| TTHM | 56.095 µg/L 70% of the EPA limit 80 µg/L
worst single sample: 86.2 µg/L | 324/324 | SYR4 | 2012–2019 |
| Dichloroacetic Acid | 24.51 µg/L No EPA limit set
worst single sample: 57.4 µg/L | 310/315 | SYR4 | 2012–2019 |
| Total Haloacetic Acids (HAA5) | 41 µg/L 68% of the EPA limit 60 µg/L
worst single sample: 99.2 µg/L | 310/315 | SYR4 | 2012–2019 |
| Trichloroacetic Acid | 15.715 µg/L No EPA limit set
worst single sample: 40.6 µg/L | 278/315 | SYR4 | 2012–2019 |
| Fluoride | 950 µg/L 24% of the EPA limit 4000 µg/L
worst single sample: 1020 µg/L | 173/384 | SYR4 | 2012–2019 |
| Dibromoacetic Acid | 3.74 µg/L No EPA limit set
worst single sample: 6.4 µg/L | 107/315 | SYR4 | 2012–2019 |
| Copper | 50 µg/L 3.8% of the EPA limit 1300 µg/L
worst single sample: 121 µg/L | 97/388 | SYR4 | 2012–2019 |
| Nitrate-Nitrite | 508000 µg/L 5080% of the EPA limit, at the 95th percentile of samples — 10000 µg/L
worst single sample: 700000 µg/L | 85/384 | SYR4 | 2012–2019 |
| Bromoform | 2.225 µg/L No EPA limit set
worst single sample: 2.9 µg/L | 52/327 | SYR4 | 2012–2019 |
| Barium | 100 µg/L 5% of the EPA limit 2000 µg/L | 39/80 | SYR4 | 2012–2019 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L | 32/32 | LCR | 2021 |
| Nitrate | 700.27 µg/L 7% of the EPA limit 10000 µg/L
worst single sample: 700.6 µg/L | 32/762 | SYR4 | 2012–2019 |
| Monochloroacetic Acid | 3.45 µg/L No EPA limit set
worst single sample: 3.7 µg/L | 31/315 | SYR4 | 2012–2019 |
| Chromium | 10 µg/L 10% of the EPA limit 100 µg/L | 14/80 | SYR4 | 2012–2019 |
| Nitrite | 400 µg/L 40% of the EPA limit 1000 µg/L | 4/372 | SYR4 | 2012–2019 |
91 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, TotalArsenicAsbestosAtrazineBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalChlorobenzeneCyanideCadmiumCarbofuranCarbon TetrachlorideChlordaneDichloromethaneDalaponDi(2-ethylhexyl) AdipateDi(2-ethylhexyl) PhthalateDinosebDiquatEthylene DibromideEndothallEndrinEthylbenzeneGlyphosateHexachlorobenzeneHfpo-DaHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoLeadMercuryMethoxychlorMonobromoacetic AcidNetfosaaNfdhaNmefosaaOxamylPfbaPFBSPfdaPfdoaPfeesaPfhpaPfhpsPfhxaPFHXSPfmbaPfmpaPFNAPFOAPFOSPfpeaPfpesPftaPftrdaPfunaPentachlorophenolPicloramSeleniumSimazineStyreneTetrachloroethyleneThallium, TotalTolueneTotal Polychlorinated Biphenyls (PCB)ToxapheneTrichloroethyleneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneLithiumO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene
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Frequently asked questions about Marin Municipal Water District
Is Marin Municipal Water District tap water safe to drink?
EPA monitoring detected 18 contaminants in Marin Municipal 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 Marin Municipal Water District's water?
EPA monitoring detected Bromodichloromethane, Chloroform, Dibromochloromethane, TTHM, Dichloroacetic Acid, and others. The full list with the level and data source for each is above.
How many people does Marin Municipal Water District serve?
Marin Municipal Water District reports serving 186,895 people in California, per its EPA record.
Has Marin Municipal Water District had any water quality violations?
The EPA has no formal drinking-water violations on file for Marin Municipal Water District.
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.