Community Water System · PWS CA4010022
Lopez Project
San Luis Obispo, California 93408 - drinking water served from surface water sources to 1,569 people, tracked in EPA SDWIS and UCMR5.
- 1,569
- People served
- 5
- EPA violations
- 4
- Health-based
- Untested
- UCMR5 result
The verdict
EPA records 5 drinking-water violations at Lopez Project, 80% of them health-based - below the California per-system average.
- 5
- Total EPA violations on record
- 80%
- Health-based (MCL / treatment failure)
- 1,569
- People served by this system
- N/A
- PFAS compounds detected (UCMR5)
Water Quality Snapshot: Lopez Project
Lopez Project is a local-owned community water system that delivers drinking water to 1,569 residents in San Luis Obispo, California (San Luis Obispo County) through 31 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 5 total violations for this system , of which 4 (80%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 1 monitoring and reporting violations are on file. The most recent violation on record dates to 2025.
The most frequently cited contaminant at this system is Coliform (TCR), recorded in 2 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%).
Lopez Project's 5 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
- 31
- County
- San Luis Obispo
- School/Daycare
- No
- MCL Violations
- 4
- Monitoring Violations
- 1
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MCL | 2 | 2008 |
| Revised Total Coliform Rule | MCL | 2 | 2025 |
| 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 Lopez Project.
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 CA4010022 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 Lopez Project 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 |
|---|---|---|---|---|
| 2025 | Revised Total Coliform Rule | MCL | 2 | SDWIS / CA4010022 / 8000 |
| 2008 | Coliform (TCR) | MCL | 2 | SDWIS / CA4010022 / 3100 |
| 1993 | Lead and Copper Rule | MR | 1 | SDWIS / CA4010022 / 5000 |
How Lopez Project Compares
Cross-reference this system's record against state averages and the federal MCL framework for context.
| Metric | Lopez Project | California avg | Federal benchmark |
|---|---|---|---|
| Total violations | 5 | 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 | 1,569 | 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 Lopez Project water safe to drink? ▼
How many people does Lopez Project serve? ▼
What type of violations does Lopez Project have? ▼
Has PFAS been detected in Lopez Project water? ▼
What water source does Lopez Project 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.