Tap Water Quality Report
Tap water quality in MONTCLAIR, California
Tap water in MONTCLAIR, California receives a grade of D (62/100) from TapWaterSafety.org. It's served by MONTE VISTA WD. The most significant water quality concerns are: Arsenic significantly above health guideline; Haloacetic acids (HAA5) significantly above health guideline; Haloacetic acids (HAA9) significantly above health guideline. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database.
What's in MONTCLAIR's tap water
Top water quality concerns identified by the EPA and Environmental Working Group across the utility serving MONTCLAIR.
Arsenic significantly above health guideline
Moderate concernArsenic detected at 2.53 ppb, 633x above the EWG health guideline of 0.004 ppb.
Haloacetic acids (HAA5) significantly above health guideline
Moderate concernHaloacetic acids (HAA5) detected at 36.2 ppb, 362x above the EWG health guideline of 0.1 ppb.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 11.4 ppb, 190x above the EWG health guideline of 0.06 ppb.
Recommended filters for MONTCLAIR
Filters matched to the specific contaminants in MONTCLAIR's water supply.
Reverse Osmosis
$249-$750Arsenic is most effectively removed by reverse osmosis. Some specialized adsorptive filters also work.
Carbon block (NSF/ANSI 42 + 53)
$40-$750Activated carbon is highly effective for disinfection byproducts like TTHM and HAA5.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
All contaminants detected in MONTCLAIR's tap water
Every contaminant identified, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal. Why we show multiple standards →
| Contaminant | Detected | EWG US health-based |
EPA US legal |
EU DWD Europe |
WHO global |
CA PHG strictest US |
Tested sample year |
Status |
|---|---|---|---|---|---|---|---|---|
| Arsenic Heavy metal |
2.53 ppb | 0.004 | 10.0 | 10 | 10 | 0.004 | — | 633× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
36.2 ppb | 0.1 | 60.0 | 60 | — | — | — | 362× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
11.4 ppb | 0.06 | — | — | — | — | — | 190× over |
| Chromium (hexavalent) Heavy metal |
2.64 ppb | 0.02 | — | — | — | — | — | 132× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
17.4 ppb | 0.15 | 80.0 | 100 | — | — | — | 116× over |
| Bromodichloromethane Disinfection byproduct |
4.4 ppb | 0.06 | — | — | — | — | — | 73× over |
| Dibromochloromethane Disinfection byproduct |
5.9 ppb | 0.1 | — | — | — | — | — | 59× over |
| Dibromoacetic acid Disinfection byproduct |
1.25 ppb | 0.03 | — | — | — | — | — | 42× over |
| Nitrate Inorganic |
3.21 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 23× over |
| Trichloroacetic acid Disinfection byproduct |
1.07 ppb | 0.1 | — | — | — | — | — | 11× over |
| Chloroform Disinfection byproduct |
3.36 ppb | 0.4 | — | — | — | — | — | 8.4× over |
| Bromoform Disinfection byproduct |
3.75 ppb | 0.5 | — | — | — | — | — | 7.5× over |
| Dichloroacetic acid Disinfection byproduct |
0.959 ppb | 0.2 | — | — | — | — | — | 4.8× over |
| 1,2-Dibromo-3-chloropropane (DBCP) Other |
0.0055 ppb | 0.0017 | 0.2 | — | — | — | — | 3.2× over |
| 1,2,3-Trichloropropane Other |
0.0011 ppb | 0.0007 | — | — | — | — | — | 1.6× over |
| Uranium Radiological |
0.44 pCi/L | 0.43 | 20.0 | 30 | 30 | 0.43 | — | 1.0× over |
| Perchlorate Disinfection byproduct |
0.546 ppb | 1.0 | — | — | — | — | — | Below guideline |
| Vanadium Other |
5.73 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Bromochloromethane Other |
0.0121 ppb | 0.06 | — | — | — | — | — | Below guideline |
| Chlorate Disinfection byproduct |
22.0 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Molybdenum Other |
2.22 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Aluminum Heavy metal |
15.0 ppb | 600.0 | — | 200 | — | 600 | — | Below guideline |
| 1,4-Dioxane Semi-volatile organic compound |
0.00542 ppb | 0.35 | — | — | 50 | 1 | — | Below guideline |
| Manganese Heavy metal |
0.725 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Strontium Radiological |
0.276 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.16 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.
Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines, California OEHHA PHGs, EWG Tap Water Database.
Treatment plant contact info
For service issues, water quality concerns, or to request a Consumer Confidence Report from MONTE VISTA WD.