Community Water System · PWS CA5010029
City of Modesto - del Rio
Modesto, California 95355 - drinking water served from groundwater sources to 1,327 people, tracked in EPA SDWIS and UCMR5.
- 1,327
- People served
- 7
- EPA violations
- 4
- Health-based
- Untested
- UCMR5 result
The verdict
EPA records 7 drinking-water violations at City of Modesto - del Rio, 57% of them health-based - below the California per-system average.
- 7
- Total EPA violations on record
- 57%
- Health-based (MCL / treatment failure)
- 1,327
- People served by this system
- N/A
- PFAS compounds detected (UCMR5)
Water Quality Snapshot: City of Modesto - del Rio
City of Modesto - del Rio is a local-owned community water system that delivers drinking water to 1,327 residents in Modesto, California (Stanislaus County) through 407 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 7 total violations for this system , of which 4 (57%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 3 monitoring and reporting violations are on file. The most recent violation on record dates to 2011.
The most frequently cited contaminant at this system is Coliform (TCR), recorded in 4 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. Statewide, 447 of 694 UCMR5-tested systems have reported PFAS detections (64.4%).
City of Modesto - del Rio's 7 violations sit below 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.
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 407
- County
- Stanislaus
- School/Daycare
- No
- MCL Violations
- 4
- Monitoring Violations
- 3
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MCL | 4 | 2011 |
| Coliform (TCR) | MR | 2 | 2001 |
| Lead and Copper Rule | MR | 1 | 1993 |
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 City of Modesto - del Rio.
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 CA5010029 on SDWISSource: EPA SDWIS Federal Reports Search
California Drinking Water Authority
California State Water Resources Control Board, Division of Drinking Water is the primacy agency that licenses and inspects City of Modesto - del Rio under EPA-delegated authority.
Open CA regulator portalSource: 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 |
|---|---|---|---|---|
| 2011 | Coliform (TCR) | MCL | 4 | SDWIS / CA5010029 / 3100 |
| 2001 | Coliform (TCR) | MR | 2 | SDWIS / CA5010029 / 3100 |
| 1993 | Lead and Copper Rule | MR | 1 | SDWIS / CA5010029 / 5000 |
How City of Modesto - del Rio Compares
Cross-reference this system's record against state averages and the federal MCL framework for context.
| Metric | City of Modesto - del Rio | California avg | Federal benchmark |
|---|---|---|---|
| Total violations | 7 | 21.1 | SDWA compliance, any non-zero count is a recorded breach |
| Health-based violations | 4 | 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 | 1,327 | 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 City of Modesto - del Rio water safe to drink? ▼
How many people does City of Modesto - del Rio serve? ▼
What type of violations does City of Modesto - del Rio have? ▼
Has PFAS been detected in City of Modesto - del Rio water? ▼
What water source does City of Modesto - del Rio use? ▼
Where does this data come from? ▼
Read our methodology - how this data is sourced, computed, and verified.
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.