PlainWater

Transient Non-Community Water System · PWS CA4100536

San Mateo County Memorial Park

Loma Mar, California 94021 - drinking water served from surface water sources to 1,790 people, tracked in EPA SDWIS and UCMR5.

1,790
People served
26
EPA violations
0
Health-based
Untested
UCMR5 result

The verdict

EPA records 26 drinking-water violations at San Mateo County Memorial Park - above the California per-system average.

26
Total EPA violations on record
0%
Health-based (MCL / treatment failure)
1,790
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: San Mateo County Memorial Park

San Mateo County Memorial Park is a local-owned transient non-community water system that delivers drinking water to 1,790 residents in Loma Mar, California (San Mateo County) through 4 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 26 total violations for this system , of which 0 (0%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 2 monitoring and reporting violations are on file. The most recent violation on record dates to 2004.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 2 violations (MR). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.

Across California, EPA tracks 7,249 public water systems serving 42,404,883 people, with 153,308 cumulative violations and 63,983 health-based violations on record. About 89% of systems in the state carry at least one violation, and state-wide the average per system is 21.1 violations. Statewide, 447 of 694 UCMR5-tested systems have reported PFAS detections (64.4%).

San Mateo County Memorial Park's 26 violations sit above the California average.

All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

Population Served
1,790
Total Violations
26
Health-Based Violations
0
Water Source
Surface Water

System Details

System Type
Transient Non-Community
Owner Type
Local
Connections
4
County
San Mateo
School/Daycare
No
MCL Violations
0
Monitoring Violations
2
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 2 2004

Verify This Water System

The figures above are aggregated from EPA's public databases. To verify the underlying records, or to file a complaint, request a Consumer Confidence Report, or check current monitoring status, go directly to the federal and state regulators that enforce the Safe Drinking Water Act for San Mateo County Memorial Park.

Federal Source of Truth

EPA SDWIS, Federal Reports

EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:

View PWS ID CA4100536 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

California Drinking Water Authority

California State Water Resources Control Board, Division of Drinking Water is the primacy agency that licenses and inspects San Mateo County Memorial Park under EPA-delegated authority.

Open CA regulator portal

Source: California State Water Resources Control Board, Division of Drinking Water

Violation Timeline

Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.

Year (latest) Contaminant Category Count EPA Record
2004 Coliform (TCR) MR 2 SDWIS / CA4100536 / 3100

How San Mateo County Memorial Park Compares

Cross-reference this system's record against state averages and the federal MCL framework for context.

Metric San Mateo County Memorial Park California avg Federal benchmark
Total violations 26 21.1 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 0 8.8 Indicates a contaminant exceeded a federal MCL
PFAS detection None 64.4% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 1,790 5,850 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 7,249 regulated public water systems in California.

Federal MCL reference, Safe Drinking Water Act thresholds
Contaminant Federal MCL / Action Level Note
Lead 0 mg/L (Action Level: 0.015 mg/L) Lead and Copper Rule treatment technique
Arsenic 0.010 mg/L (10 ppb) Health-based MCL since 2006
Total Coliform Treatment technique (RTCR) Indicator organism, monitoring trigger
PFOA / PFOS (PFAS) 4.0 ppt each (final 2024 rule) Compliance deadline 2029 (EPA proposed extending to 2031, not yet final as of May 2026)
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is San Mateo County Memorial Park water safe to drink?
San Mateo County Memorial Park (PWS ID: CA4100536) has 26 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 1,790 people using Surface Water sources.
How many people does San Mateo County Memorial Park serve?
San Mateo County Memorial Park serves 1,790 people in Loma Mar, California. It is a Local-owned system using Surface Water water sources with 4 service connections.
What type of violations does San Mateo County Memorial Park have?
San Mateo County Memorial Park has 26 total violations: 0 health-based violations (MCL exceedances or treatment failures), 2 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in San Mateo County Memorial Park water?
No PFAS testing data is available for San Mateo County Memorial Park under the EPA's UCMR5 monitoring program.
What water source does San Mateo County Memorial Park use?
San Mateo County Memorial Park uses Surface Water as its primary water source. It is classified as a Transient Non-Community Water System, serving transient populations.
Where does this data come from?
All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. This data is provided for informational purposes only.
Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This system's figures are rendered directly from EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.