PlainWater

MOUNTAIN HOUSE SCHOOL

PWS ID: CA0105009 · BYRON, California 94514-1920

MOUNTAIN HOUSE SCHOOL serves 50 people in BYRON, California using Surface Water water sources. It has 13 recorded EPA violations, including 2 health-based violations. No PFAS contamination was detected in UCMR5 testing.

Water Quality Snapshot: MOUNTAIN HOUSE SCHOOL

MOUNTAIN HOUSE SCHOOL is a local-owned non-transient non-community water system that delivers drinking water to 50 residents in BYRON, California (Alameda County) through 1 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 13 total violations for this system , of which 2 (15%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 8 monitoring and reporting violations are on file. The most recent violation on record dates to 2001.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 4 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. MOUNTAIN HOUSE SCHOOL's 13 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
50
Total Violations
13
Health-Based Violations
2
Water Source
Surface Water

System Details

System Type
Non-Transient Non-Community
Owner Type
Local
Connections
1
County
Alameda
School/Daycare
Yes
MCL Violations
2
Monitoring Violations
8
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 4 1995
Coliform (TCR) MCL 2 1995
Arsenic MR 2 2001
Nitrate MR 2 2001

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 MOUNTAIN HOUSE SCHOOL.

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 CA0105009 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 MOUNTAIN HOUSE SCHOOL 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
2001 Arsenic MR 2 SDWIS / CA0105009 / 1005
2001 Nitrate MR 2 SDWIS / CA0105009 / 1040
1995 Coliform (TCR) MR 4 SDWIS / CA0105009 / 3100
1995 Coliform (TCR) MCL 2 SDWIS / CA0105009 / 3100

How MOUNTAIN HOUSE SCHOOL Compares

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

Metric MOUNTAIN HOUSE SCHOOL California avg Federal benchmark
Total violations 13 21.1 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 2 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 50 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 MOUNTAIN HOUSE SCHOOL water safe to drink?
MOUNTAIN HOUSE SCHOOL (PWS ID: CA0105009) has 13 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 50 people using Surface Water sources.
How many people does MOUNTAIN HOUSE SCHOOL serve?
MOUNTAIN HOUSE SCHOOL serves 50 people in BYRON, California. It is a Local-owned system using Surface Water water sources with 1 service connections.
What type of violations does MOUNTAIN HOUSE SCHOOL have?
MOUNTAIN HOUSE SCHOOL has 13 total violations: 2 health-based violations (MCL exceedances or treatment failures), 8 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in MOUNTAIN HOUSE SCHOOL water?
No PFAS testing data is available for MOUNTAIN HOUSE SCHOOL under the EPA's UCMR5 monitoring program.
What water source does MOUNTAIN HOUSE SCHOOL use?
MOUNTAIN HOUSE SCHOOL uses Surface Water as its primary water source. It is classified as a Non-Transient Non-Community Water System, serving the same people for at least 6 months per year.
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 Kiznis Studio Editorial