A
89

US Water Score: A

Monterey Park, CA 91755

Los Angeles County · Population served: 248,000 · Data updated July 2026

Service-area evidence: EPA service-area records associate the listed system with this ZIP. Boundaries may still overlap or change.

Water Systems Serving This Area

🌊
SAN GABRIEL VALLEY WATER CO.-EL MONTE
Groundwater · Pop. 248,000
PWSID: CA1910039
🌊
MONTEREY PARK-CITY, WATER DEPT.
Groundwater · Pop. 62,183
PWSID: CA1910092
🏔
GSWC-SOUTH SAN GABRIEL
Surface water · Pop. 26,240
PWSID: CA1910223

Contaminants Detected

ContaminantDetected LevelEPA MCLHealth GuidelineStatus
Lead
0.0
15 ppb 1 ppb Passed

PFAS / Forever Chemicals

2 detected Below comparison values

UCMR5 occurrence results are screening information, not a finding of regulatory compliance or noncompliance. PFAS rules and compliance dates are evolving.

CompoundLevelEPA MCLHealth GuidelineStatus
PFBA10.0 pptNo standard500 pptNo federal MCL shown
PFPeA5.6 pptNo standardNo federal MCL shown

Violation History (Last 5 Years)

3Total (5yr)
1Health-Based
0Major

Water Quality Summary

Understanding Your Water in Monterey Park

Tap water quality in Monterey Park, California (91755) receives an overall grade of A (Lower record-based concern) with a score of 89 out of 100, based on analysis of EPA compliance data, contaminant testing, and violation history. This is roughly in line with the California state average of 92. Compared to the national average (75), this area performs significantly better. The area is served by 3 water systems providing water to approximately 248,000 people, using groundwater and surface water sources. PFAS testing detected 2 compounds, all below the EPA final MCL values used for comparison. Over the past 5 years, water systems here have accumulated 3 violations, including 1 health-based violations.

Your Score 89/100 A
vs State 4 pts below California avg (92)
vs National 14 pts above national avg (75)

What a Grade A Means

A score of 89/100 means public water-system records for Monterey Park, CA show relatively few concerns in the US Water Score model. This is an internal score, not an EPA safety rating, and it does not guarantee conditions at any specific tap.

Groundwater: drawn from underground aquifers via wells
Surface water: sourced from rivers, lakes, or reservoirs

Health Information

What These Contaminants Mean for You

⚠️

Lead in Your Water

Lead is a toxic metal that can leach from aging pipes and plumbing fixtures.

Health Effects

Even low levels of lead exposure can cause developmental delays in children, kidney damage, and cardiovascular effects in adults. The EPA action level is 15 ppb, but health experts recommend no safe level of lead in drinking water.

Common Sources

Lead enters water primarily through corrosion of lead service lines, lead solder, and brass fixtures — especially in homes built before 1986.

What You Can Do

If lead is detected above 1 ppb, consider using a certified lead-removal filter (NSF/ANSI 53) for drinking and cooking water. Run cold water for 30 seconds before use if water has been sitting in pipes.

Common Questions

Frequently Asked Questions

Based on public water-system records, Monterey Park, California receives an internal US Water Score grade of A (Lower record-based concern) with a score of 89/100. This indicates relatively few system-level concerns in our model, but it is not an EPA safety rating and does not guarantee tap conditions inside individual homes.

ZIP code 91755 is served by 3 water systems using groundwater, surface water sources, providing water to approximately 248,000 people. Multiple source types mean your water may come from a blend of surface and underground sources.

Lead levels in Monterey Park, California are 0.0 ppb, which is at or below the health guideline of 1 ppb. This is a positive result, though periodic testing is still recommended.

2 PFAS compounds were detected in water serving Monterey Park, California, with reported values below the EPA final MCL values used by this site. This comparison is informational: federal compliance timelines and the status of some PFAS standards are still evolving. Activated carbon or reverse osmosis filters can reduce some PFAS when appropriately certified and maintained.

Water systems serving Monterey Park, California have received 3 violations in the last 5 years, including 1 health-based violation. Violations can range from paperwork issues (monitoring & reporting) to serious health-based violations where contaminant levels exceeded safe limits. Review the violation details above for specifics.

Based on detected contaminants (PFAS), residents in Monterey Park, California should consider: Reverse osmosis (RO) system — most effective for PFAS, lead, and other contaminants. Always look for filters with NSF/ANSI certification for the specific contaminants you want to remove.

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