Tap Water Quality Report
Tap water quality in MONTEREY PARK, California
Tap water in MONTEREY PARK, California receives a grade of F (39/100) from TapWaterSafety.org. It's served by MONTEREY PARK-CITY, WATER DEPT.. The most significant water quality concerns are: PFAS contamination; Perfluorohexane sulfonate (PFHXS) significantly above health guideline; Haloacetic acids (HAA5) significantly above health guideline; Arsenic significantly above health guideline. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database.
What's in MONTEREY PARK's tap water
Top water quality concerns identified by the EPA and Environmental Working Group across the utility serving MONTEREY PARK.
PFAS contamination
Severe concernPerfluorooctane sulfonate (PFOS), Perfluorooctanoic acid (PFOA) detected. PFAS are persistent chemicals linked to cancer and immune effects with no known safe exposure threshold.
Perfluorohexane sulfonate (PFHXS) significantly above health guideline
Moderate concernPerfluorohexane sulfonate (PFHXS) detected at 0.663 ppt, 663x above the EWG health guideline of 0.001 ppt.
Haloacetic acids (HAA5) significantly above health guideline
Moderate concernHaloacetic acids (HAA5) detected at 34.9 ppb, 349x above the EWG health guideline of 0.1 ppb.
Arsenic significantly above health guideline
Moderate concernArsenic detected at 1.18 ppb, 295x above the EWG health guideline of 0.004 ppb.
EPA compliance record
Official U.S. EPA records for MONTEREY PARK-CITY, WATER DEPT. (system ID CA1910092) for the last 3 years. Checked 2026-10-07.
| Rule | Type | Since | Status |
|---|---|---|---|
| Lead and Copper Rule Revisions | Missed reporting | 10/17/2024 | Open |
| Lead and Copper Rule Revisions | Required treatment not met | 10/17/2024 | Open |
Source: U.S. EPA Enforcement and Compliance History Online (ECHO), from the Safe Drinking Water Information System. See EPA's full report.
Recommended filters for MONTEREY PARK
Filters matched to the specific contaminants in MONTEREY PARK's water supply.
Filter certified for PFOA/PFOS (NSF/ANSI 53 or 58)
$180-$750Reverse osmosis and some carbon block filters reduce PFAS. Look for certification to NSF/ANSI 53 or 58 for PFOA/PFOS.
Carbon filter certified for VOCs (NSF/ANSI 53)
$180-$599Activated carbon is effective for disinfection byproducts. Look for NSF/ANSI 53 VOC reduction.
Reverse osmosis certified for arsenic (NSF/ANSI 58)
$429-$599Reverse osmosis certified under NSF/ANSI 58 for arsenic is the most reliable home option.
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 MONTEREY PARK'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 |
|---|---|---|---|---|---|---|---|---|
| Perfluorohexane sulfonate (PFHXS) PFAS |
0.663 ppt | 0.001 | 10.0 | — | — | — | — | 663× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
34.9 ppb | 0.1 | 60.0 | 60 | — | — | — | 349× over |
| Arsenic Heavy metal |
1.18 ppb | 0.004 | 10.0 | 10 | 10 | 0.004 | — | 295× over |
| Chromium (hexavalent) Heavy metal |
2.8 ppb | 0.02 | — | — | — | — | — | 140× over |
| Dibromoacetic acid Disinfection byproduct |
1.21 ppb | 0.03 | — | — | — | — | — | 40× over |
| Nitrate and nitrite Inorganic |
5.0 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 36× over |
| Nitrate Inorganic |
4.04 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 29× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
3.43 ppb | 0.15 | 80.0 | 100 | — | — | — | 23× over |
| Perfluorooctanoic acid (PFOA) PFAS |
1.89 ppt | 0.09 | 4.0 | 100 | 100 | 0.007 | — | 21× over |
| Uranium Radiological |
6.88 pCi/L | 0.43 | 20.0 | 30 | 30 | 0.43 | — | 16× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
0.879 ppb | 0.06 | — | — | — | — | — | 15× over |
| Dibromochloromethane Disinfection byproduct |
1.09 ppb | 0.1 | — | — | — | — | — | 11× over |
| Bromoform Disinfection byproduct |
2.47 ppb | 0.5 | — | — | — | — | — | 4.9× over |
| Perfluorooctane sulfonate (PFOS) PFAS |
1.12 ppt | 0.3 | 4.0 | 100 | 100 | 1 | — | 3.7× over |
| 1,4-Dioxane Semi-volatile organic compound |
0.3 ppb | 0.35 | — | — | 50 | 1 | — | Below guideline |
| Dichloroacetic acid Disinfection byproduct |
0.112 ppb | 0.2 | — | — | — | — | — | Below guideline |
| Chlorate Disinfection byproduct |
62.5 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Vanadium Other |
4.07 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Molybdenum Other |
5.87 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Perchlorate Disinfection byproduct |
0.143 ppb | 1.0 | — | — | — | — | — | Below guideline |
| Manganese Heavy metal |
6.08 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Perfluorohexanoic Acid (PFHxA) PFAS |
1.08 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.5 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Perfluoroheptanoic acid (PFHPA) PFAS |
0.263 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluorobutane sulfonate (PFBS) PFAS |
0.431 ppt | 2000.0 | — | — | — | — | — | Below guideline |
| Chloromethane Other |
0.000275 ppb | 2.69 | — | — | — | — | — | Below guideline |
| 1,1-Dichloroethane Volatile organic compound |
0.000154 ppb | 3.0 | — | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.631 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 MONTEREY PARK-CITY, WATER DEPT..