Water Quality in Monterey Park, CA: 6 Violations — Grade B
Grade B · Score 77/100 · 1 water system · Updated 2026-05-03
Monterey Park's water is mostly safe. Minor violations exist but are primarily monitoring-related.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
On record with EPA: Monterey Park, CA has 6 water violations.
Water Quality by ZIP Code in Monterey Park
Water quality varies across Monterey Park's 3 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 91754 | B | 74 | 2 | 1 | View report → |
| 91755 | B | 79 | 2 | 1 | View report → |
| 91756 | B | 79 | 2 | 1 | View report → |
Water Quality Overview
Monterey Park, California receives a water quality grade of B with an overall score of 77 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
The 1 water system serving Monterey Park have accumulated 6 EPA violations, including 3 health-based violations. These violations are tracked across 3 ZIP codes serving approximately 62,183 people.
What Grade B Means
A grade of B indicates good compliance with EPA drinking water standards. While not perfect, Monterey Park's water systems meet the vast majority of federal requirements. Minor violations may exist but typically relate to monitoring or reporting rather than health-based standards.
Lead Levels
The average 90th percentile lead level across Monterey Park water systems is 0.0007 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
With 84% of homes built before 1986, Monterey Park has a higher-than-average risk of lead from older plumbing. Lead solder was banned in 1986, and homes built before this date may have lead in pipes, solder joints, or fixtures.
Radon Risk
Monterey Park is in EPA Radon Zone 2 (Moderate risk). Testing is recommended, especially for homes with basements or ground-level living spaces.
Water Systems Serving Monterey Park
Monterey Park is served by 1 community water system regulated under the Safe Drinking Water Act. These systems collectively serve approximately 62,183 people across 3 ZIP codes.
Each water system is identified by a Public Water System ID (PWSID) and is required to:
- Test for over 90 regulated contaminants on a regular schedule
- Report results to the EPA and state regulators
- Issue an annual Consumer Confidence Report (CCR) to all customers
- Take corrective action when violations occur
How to Check Your Water in Monterey Park
Enter your ZIP code on ZipCheckup to see your specific water system data, including contaminant levels, violation history, and safety scores
Request your CCR — your water utility must provide an annual Consumer Confidence Report with detailed test results for all monitored contaminants
Get a home test — certified kits cost $20–$50 and test for lead, bacteria, and common contaminants. Professional lab tests ($150–$400) cover a broader panel
Consider filtration — NSF-certified filters can remove specific contaminants. Reverse osmosis removes the broadest range; activated carbon is effective for chlorine and many organics
Check for advisories — monitor your local utility website and local news for boil water advisories or system alerts
Contaminants Detected in Monterey Park Water Systems
The following contaminants have been detected or caused violations across Monterey Park's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Stage 2 DBP Rule | Treatment Technique | N/A | 6 | 3 | Yes |
MCL = Maximum Contaminant Level (EPA enforceable standard). Health-based violations indicate levels that may pose direct health risks.
Monterey Park vs. Nearby California Cities
How Monterey Park's water quality compares to similar cities in California:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Monterey Park | B | 6 | 1 | 62,183 |
| San Rafael | C | 0 | 2 | 61,991 |
| Pittsburg | B | 0 | 1 | 62,500 |
| Pico Rivera | B | 15 | 2 | 62,651 |
Water Quality by ZIP Code in Monterey Park
Water quality varies across Monterey Park's ZIP codes. The table below shows the worst-scoring and best-scoring areas:
Common Questions About Monterey Park Water
These are the most common questions residents search for about water quality in Monterey Park, California:
Is Monterey Park water hard or soft? Water hardness varies by source. Monterey Park's 1 water system uses a single source. Check your ZIP code report for specific hardness data.
Can I drink Monterey Park tap water? Monterey Park's water receives a grade of B (77/100). There are 3 health-based violations — consider filtration.
What is the best water filter for Monterey Park? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Monterey Park vs. California Average
Understanding how Monterey Park compares to the broader California average helps contextualize your local water quality. Factors like water source, treatment methods, and infrastructure age all contribute to differences between cities in the same state.
To see how individual neighborhoods compare, check the ZIP code reports below — water quality can vary significantly even within Monterey Park.
ZIP Codes in Monterey Park
Monterey Park spans 3 ZIP codes. The ZIP with the lowest water quality score is 91754. Each ZIP code has its own water quality profile based on the specific water system serving that area. Check each ZIP code for detailed contaminant data, violation history, and system information.
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
- Enforcement: EPA ECHO database
- Filter recommendations: NSF/ANSI certified products
Updated daily.
Frequently Asked Questions
Your Water is Safe — Here's How to Keep It That Way
Grade B is excellent news. Here's what proactive homeowners do to maintain water quality:
Annual Water Testing
EPA recommends annual testing even with clean water. Home test kits: $20-$50. Catches changes before they become problems.
Maintenance Filtration
A basic carbon filter removes chlorine taste and catches emerging contaminants like PFAS that aren't yet fully regulated.
Plumbing Check
Even safe city water picks up lead from home pipes. If your home was built before 1986, a one-time pipe inspection is recommended.