Public water system record
City of Norco
Serves Norco, Riverside County, CA · 25,068 people served
Federal records show 1 health-based violation and 42 monitoring/reporting issues for City of Norco in the last ten years. The most serious issue in this window was a Total Trihalomethanes (TTHMs) violation that EPA lists as archived, not resolved.
System profile
- Health-based violations, last 10 years
- 1
- Resolved
- 0
- Unresolved
- 0
- Archived by EPA
- 1
- Any acute record
- No
- Monitoring issues, last 10 years
- 42
Key facts
- City of Norco draws water from 1 well.
- Highest measured level in the last 10 years: Total Trihalomethanes (TTHMs), 0.083 mg/L, federal limit 0.08 mg/L (at or just above the limit), 2025.
- Most recent formal enforcement: compliance order (no penalty) by California, October 2025.
- Record on file since 1979, with 16 health-based violations before October 19, 2016.
- Lead pipe inventory: 0 lead and 0 unknown out of 7,958 service lines.
Check whether City of Norco serves your address
Health-based violations
Since October 2016Violation data reflects EPA records through March 2026. For the most current status, visit the EPA ECHO database.
| Contaminant | Rule family | Start date | Status | Acute |
|---|---|---|---|---|
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.083 mg/L, federal limit 0.08 mg/L (at or just above the limit)
|
220 | Jul 1, 2025 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
Monitoring and reporting issues
Since October 2016Missed tests or reports, not contaminants found above a limit.
| Issue | Start date | Status |
|---|---|---|
|
Chlordane
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
ETHYLENE DIBROMIDE
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
1,2-DIBROMO-3-CHLOROPROPANE
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Total Polychlorinated Biphenyls (PCB)
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Pentachlorophenol
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Benzo(a)pyrene
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
HEXACHLOROBENZENE
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
2,4,5-TP
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
2,4-D
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Heptachlor epoxide
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Heptachlor
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
2,3,7,8-TCDD
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
LASSO
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Atrazine
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Carbofuran
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Hexachlorocyclopentadiene
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Dinoseb
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Picloram
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Di(2-ethylhexyl) phthalate
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Simazine
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
OXAMYL
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Di(2-ethylhexyl) adipate
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Glyphosate
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Endothall
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Diquat
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Dalapon
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Toxaphene
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Methoxychlor
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
BHC-GAMMA
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Endrin
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Selenium
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Thallium, Total
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Beryllium, Total
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Antimony, Total
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Nitrite
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Nickel
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Mercury
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Fluoride
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Chromium (total)
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Cadmium
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Barium
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Arsenic
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
Full record since 1979
EPA's records for City of Norco go back to 1979. Before October 19, 2016 they list 16 health-based violations (12 resolved, 4 archived by EPA without a recorded fix) and 12 monitoring or reporting violations.
| Violations that began in | Health-based | Monitoring and reporting |
|---|---|---|
| 1970s | 1 | 1 |
| 1980s | 3 | 1 |
| 1990s | 7 | 1 |
| 2000s | 3 | 6 |
| 2010 to October 18, 2016 | 2 | 3 |
| 2020s | 1 | 42 |
Most recent health-based violation before October 19, 2016: Total Coliform, began April 2013, Resolved.
Show all 16 health-based violations before October 19, 2016
| Contaminant | Start date | Status |
|---|---|---|
|
Total Coliform
Contaminant limit exceeded
|
Apr 1, 2013 | Resolved |
|
Nitrate (acute)
Contaminant limit exceeded
|
Sep 1, 2011 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
|
Jul 1, 2007 | Resolved |
|
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
|
Apr 1, 2007 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Aug 1, 2003 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Jan 1, 1996 | Resolved |
|
Nitrate (acute)
Contaminant limit exceeded
|
Aug 1, 1995 | Resolved |
|
Nitrate (acute)
Contaminant limit exceeded
|
Sep 1, 1994 | Resolved |
|
Nitrate (acute)
Contaminant limit exceeded
|
Aug 1, 1994 | Resolved |
|
Nitrate (acute)
Contaminant limit exceeded
|
Feb 1, 1994 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Jan 1, 1994 | Resolved |
|
Nitrate (acute)
Contaminant limit exceeded
|
Jun 1, 1993 | Resolved |
|
Fluoride
Contaminant limit exceeded
|
Jun 1, 1986 | Archived |
|
Nitrate (acute)
Contaminant limit exceeded
|
Oct 1, 1980 | Archived |
|
Nitrate (acute)
Contaminant limit exceeded
|
Jul 28, 1980 | Archived |
|
Nitrate (acute)
Contaminant limit exceeded
|
Oct 28, 1979 | Archived |
Enforcement actions
California regulators took 9 formal enforcement actions against City of Norco between 1994 and 2025. The most recent was a compliance order (no penalty) in October 2025.
| Date | By | Action | Violations covered |
|---|---|---|---|
| Oct 7, 2025 | California | Compliance order (no penalty) | 1 violation (1 health-based): Total Trihalomethanes (TTHMs) |
| Sep 2, 2025 | California | Compliance order (no penalty) | 42 violations: Nickel, Nitrite, Antimony, Total, Beryllium, Total, Thallium, Total |
| May 6, 2013 | California | Compliance order (no penalty) | 2 violations (1 health-based): Total Coliform, Groundwater Rule |
| Sep 9, 2003 | California | Compliance order (no penalty) | 1 violation (1 health-based): Total Coliform |
| Oct 17, 2001 | California | Compliance order (no penalty) | 1 violation: Consumer Confidence Rule |
| Dec 5, 1995 | California | Compliance order (no penalty) | 1 violation (1 health-based): Nitrate |
| Dec 1, 1995 | California | Compliance order (no penalty) | 6 violations (5 health-based): Nitrate |
| Oct 18, 1994 | California | Administrative penalty | 3 violations (2 health-based): Nitrate |
| Mar 24, 1994 | California | Administrative penalty | 1 violation (1 health-based): Nitrate |
What the violations mean
Total Trihalomethanes (TTHMs)
1 incidentDisinfection byproduct levels exceeded the federal limit
Long-term TTHM exposure may increase bladder cancer risk
Where the water comes from
City of Norco draws water from 1 well. It also buys water from Western MWD (Arlington), Jurupa Community SD, City of Corona, City of Riverside and Chino Basin Desalter Auth. - Desalter 2. 1 other community water system buys water from City of Norco. 1 other public water system has an emergency connection to City of Norco.
Buys water from
- Western MWD (Arlington) Riverside, CA
- Jurupa Community SD Jurupa Valley, CA
- City of Corona Corona, CA
- City of Riverside Riverside, CA
- Chino Basin Desalter Auth. - Desalter 2 Ontario, CA
Community systems that buy water from it
- California Rehabilitation Center - Norco Norco, CA
Annual water quality report
City of Norco must give its customers an annual water quality report (Consumer Confidence Report) by July 1, with the levels its tests found in the previous year.
Systems serving 10,000 or more people must mail or deliver the report to every customer, and from 2027 they must send it twice a year.
Find a posted report with EPA's Consumer Confidence Report search
Testing your own water
To test the water at your tap, or a private well this record does not cover, use a laboratory certified for drinking water by California.
Certified drinking water labs by state EPA guidance for private wells