PlainWater

LAKE YOSEMITE COUNTY PARK

PWS ID: CA2400114 · MERCED, California 95340

LAKE YOSEMITE COUNTY PARK serves 1,200 people in MERCED, California using Groundwater water sources. It has 19 recorded EPA violations, including 15 health-based violations. No PFAS contamination was detected in UCMR5 testing.

Water Quality Snapshot: LAKE YOSEMITE COUNTY PARK

LAKE YOSEMITE COUNTY PARK is a local-owned transient non-community water system that delivers drinking water to 1,200 residents in MERCED, California (Merced County) through 24 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 19 total violations for this system , of which 15 (79%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 4 monitoring and reporting violations are on file. The most recent violation on record dates to 2016.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 15 violations (MCL, health-based). 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. LAKE YOSEMITE COUNTY PARK's 19 violations sit below the California average. Statewide, 447 of 694 UCMR5-tested systems have reported PFAS detections (64.4%). 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
1,200
Total Violations
19
Health-Based Violations
15
Water Source
Groundwater

System Details

System Type
Transient Non-Community
Owner Type
Local
Connections
24
County
Merced
School/Daycare
No
MCL Violations
15
Monitoring Violations
4
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MCL 15 2011
Coliform (TCR) MR 2 2012
Nitrate MR 2 2016

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 LAKE YOSEMITE COUNTY 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 CA2400114 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 LAKE YOSEMITE COUNTY 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
2016 Nitrate MR 2 SDWIS / CA2400114 / 1040
2012 Coliform (TCR) MR 2 SDWIS / CA2400114 / 3100
2011 Coliform (TCR) MCL 15 SDWIS / CA2400114 / 3100

How LAKE YOSEMITE COUNTY PARK Compares

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

Metric LAKE YOSEMITE COUNTY PARK California avg Federal benchmark
Total violations 19 21.1 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 15 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 1,200 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
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is LAKE YOSEMITE COUNTY PARK water safe to drink?
LAKE YOSEMITE COUNTY PARK (PWS ID: CA2400114) has 19 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 1,200 people using Groundwater sources.
How many people does LAKE YOSEMITE COUNTY PARK serve?
LAKE YOSEMITE COUNTY PARK serves 1,200 people in MERCED, California. It is a Local-owned system using Groundwater water sources with 24 service connections.
What type of violations does LAKE YOSEMITE COUNTY PARK have?
LAKE YOSEMITE COUNTY PARK has 19 total violations: 15 health-based violations (MCL exceedances or treatment failures), 4 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in LAKE YOSEMITE COUNTY PARK water?
No PFAS testing data is available for LAKE YOSEMITE COUNTY PARK under the EPA's UCMR5 monitoring program.
What water source does LAKE YOSEMITE COUNTY PARK use?
LAKE YOSEMITE COUNTY PARK uses Groundwater 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.

Explore PlainWater

Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. This data is provided for informational purposes only.

Related

Data sourced from $official public datasets. See our methodology for details. Retrieved and formatted by PlainWater Editorial