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IMPROVEMENT DISTRICT NO. 1

PWS ID: CA5400968 · THREE RIVERS, California 93271

IMPROVEMENT DISTRICT NO. 1 serves 200 people in THREE RIVERS, California using Surface Water water sources. It has 112 recorded EPA violations, including 31 health-based violations. No PFAS contamination was detected in UCMR5 testing.

Water Quality Snapshot: IMPROVEMENT DISTRICT NO. 1

IMPROVEMENT DISTRICT NO. 1 is a local-owned community water system that delivers drinking water to 200 residents in THREE RIVERS, California (Tulare County) through 80 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 112 total violations for this system , of which 31 (28%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 50 monitoring and reporting violations are on file. The most recent violation on record dates to 2019.

The most frequently cited contaminant at this system is Surface Water Treatment Rule, recorded in 23 violations (TT, 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. IMPROVEMENT DISTRICT NO. 1's 112 violations sit above 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
200
Total Violations
112
Health-Based Violations
31
Water Source
Surface Water

System Details

System Type
Community
Owner Type
Local
Connections
80
County
Tulare
School/Daycare
No
MCL Violations
2
Monitoring Violations
50
Treatment Tech Violations
29

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Surface Water Treatment Rule TT 23 2011
Surface Water Treatment Rule MR 22 2008
Nitrate MR 9 2017
Long Term 2 Enhanced Surface Water Treatment Rule TT 6 2014
Lead and Copper Rule MR 5 2013
Coliform (TCR) MR 4 2014
Consumer Confidence Rule Other 3 2003
TTHM MR 2 2013
Nitrate-Nitrite MR 2 2015
Revised Total Coliform Rule MON 2 2019
Gross Alpha, Excl. Radon and U MR 2 1981
Coliform (TCR) MCL 2 2011
Total Haloacetic Acids (HAA5) MR 2 2013

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 IMPROVEMENT DISTRICT NO. 1.

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 CA5400968 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 IMPROVEMENT DISTRICT NO. 1 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
2019 Revised Total Coliform Rule MON 2 SDWIS / CA5400968 / 8000
2017 Nitrate MR 9 SDWIS / CA5400968 / 1040
2015 Nitrate-Nitrite MR 2 SDWIS / CA5400968 / 1038
2014 Long Term 2 Enhanced Surface Water Treatment Rule TT 6 SDWIS / CA5400968 / 0800
2014 Coliform (TCR) MR 4 SDWIS / CA5400968 / 3100
2013 Lead and Copper Rule MR 5 SDWIS / CA5400968 / 5000
2013 TTHM MR 2 SDWIS / CA5400968 / 2950
2013 Total Haloacetic Acids (HAA5) MR 2 SDWIS / CA5400968 / 2456
2011 Surface Water Treatment Rule TT 23 SDWIS / CA5400968 / 0200
2011 Coliform (TCR) MCL 2 SDWIS / CA5400968 / 3100
2008 Surface Water Treatment Rule MR 22 SDWIS / CA5400968 / 0200
2003 Consumer Confidence Rule Other 3 SDWIS / CA5400968 / 7000
1981 Gross Alpha, Excl. Radon and U MR 2 SDWIS / CA5400968 / 4000

How IMPROVEMENT DISTRICT NO. 1 Compares

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

Metric IMPROVEMENT DISTRICT NO. 1 California avg Federal benchmark
Total violations 112 21.1 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 31 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 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 IMPROVEMENT DISTRICT NO. 1 water safe to drink? ▼
IMPROVEMENT DISTRICT NO. 1 (PWS ID: CA5400968) has 112 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 200 people using Surface Water sources.
How many people does IMPROVEMENT DISTRICT NO. 1 serve? ▼
IMPROVEMENT DISTRICT NO. 1 serves 200 people in THREE RIVERS, California. It is a Local-owned system using Surface Water water sources with 80 service connections.
What type of violations does IMPROVEMENT DISTRICT NO. 1 have? ▼
IMPROVEMENT DISTRICT NO. 1 has 112 total violations: 31 health-based violations (MCL exceedances or treatment failures), 50 monitoring/reporting violations, and 29 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in IMPROVEMENT DISTRICT NO. 1 water? ▼
No PFAS testing data is available for IMPROVEMENT DISTRICT NO. 1 under the EPA's UCMR5 monitoring program.
What water source does IMPROVEMENT DISTRICT NO. 1 use? ▼
IMPROVEMENT DISTRICT NO. 1 uses Surface Water as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.
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.

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

Read our methodology — how this data is sourced, computed, and verified.

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