Water Quality in NAPA, CA (94558)

EPA violation data for public water systems serving ZIP code 94558.

138

Total Violations

Health-Based

116

Monitoring / Reporting

119

Resolved

What does this mean?

119 of 138 violations have been resolved. 22 are health-based violations, meaning contaminant levels exceeded federal safety limits. The remaining 116 are monitoring or reporting violations (missed testing deadlines or late paperwork — not necessarily a water quality issue). Not all violations mean your water is unsafe. The EPA requires reporting even for minor administrative issues.

Water systems: 120 Population served: 18,808

Violations Detail (138 total)

Contaminant	Category	MCL Limit	Measured	Date	Status	Health Effects
Lead and Copper Rule	Monitoring	N/A	N/A	Jun 30, 2025	Active	N/A
Bromate	Health-Based	N/A	110	Dec 31, 2024	Resolved	Increased risk of cancer
Bromate	Health-Based	N/A	110	Dec 31, 2024	Resolved	Increased risk of cancer
LEAD AND COPPER RULE REVISIONS	Health-Based	N/A	N/A	Oct 16, 2024	Active	N/A
LEAD AND COPPER RULE REVISIONS	Monitoring	N/A	N/A	Oct 16, 2024	Active	N/A
LEAD AND COPPER RULE REVISIONS	Monitoring	N/A	N/A	Oct 16, 2024	Active	N/A
LEAD AND COPPER RULE REVISIONS	Health-Based	N/A	N/A	Oct 16, 2024	Active	N/A
LEAD AND COPPER RULE REVISIONS	Monitoring	N/A	N/A	Oct 16, 2024	Active	N/A
LEAD AND COPPER RULE REVISIONS	Health-Based	N/A	N/A	Oct 16, 2024	Active	N/A
LEAD AND COPPER RULE REVISIONS	Health-Based	N/A	N/A	Oct 16, 2024	Active	N/A
LEAD AND COPPER RULE REVISIONS	Monitoring	N/A	N/A	Oct 16, 2024	Active	N/A
LEAD AND COPPER RULE REVISIONS	Health-Based	N/A	N/A	Oct 16, 2024	Active	N/A
LEAD AND COPPER RULE REVISIONS	Monitoring	N/A	N/A	Oct 16, 2024	Active	N/A
LEAD AND COPPER RULE REVISIONS	Monitoring	N/A	N/A	Oct 16, 2024	Active	N/A
LEAD AND COPPER RULE REVISIONS	Health-Based	N/A	N/A	Oct 16, 2024	Active	N/A
LEAD AND COPPER RULE REVISIONS	Health-Based	N/A	N/A	Oct 16, 2024	Active	N/A
LEAD AND COPPER RULE REVISIONS	Monitoring	N/A	N/A	Oct 16, 2024	Active	N/A
LEAD AND COPPER RULE REVISIONS	Monitoring	N/A	N/A	Oct 16, 2024	Active	N/A
LEAD AND COPPER RULE REVISIONS	Health-Based	N/A	N/A	Oct 16, 2024	Active	N/A
LEAD AND COPPER RULE REVISIONS	Monitoring	N/A	N/A	Oct 16, 2024	Active	N/A
LEAD AND COPPER RULE REVISIONS	Health-Based	N/A	N/A	Oct 16, 2024	Active	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2024	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2024	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2024	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2024	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2024	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2024	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2024	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2024	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Nitrate	Monitoring	N/A	N/A	Dec 31, 2023	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2023	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Lead and Copper Rule	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	N/A
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
E. COLI	Monitoring	0	N/A	Aug 31, 2022	Resolved	Severe gastrointestinal illness; may be fatal in vulnerable populations
E. COLI	Monitoring	0	N/A	Aug 31, 2022	Resolved	Severe gastrointestinal illness; may be fatal in vulnerable populations
Revised Total Coliform Rule	Monitoring	N/A	N/A	Aug 31, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2022	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	May 31, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Apr 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Mar 31, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jan 31, 2022	Resolved	N/A
Nitrate	Health-Based	N/A	14.4	Dec 31, 2021	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Lead and Copper Rule	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	N/A
Nitrate	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2021	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2021	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2021	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2021	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Sep 30, 2021	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Sep 30, 2021	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2021	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2021	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2021	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2021	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2021	Resolved	N/A
Selenium	Health-Based	N/A	130	Jun 30, 2021	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
Selenium	Health-Based	N/A	130	Jun 30, 2021	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jun 30, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jun 30, 2021	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Jun 30, 2021	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Jun 30, 2021	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Jun 30, 2021	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Jun 30, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Mar 31, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Mar 31, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Mar 31, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Mar 31, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Mar 31, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Mar 31, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Mar 31, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Mar 31, 2021	Resolved	N/A

Lead & Copper Levels

Violation Timeline

2025(1)

Lead and Copper Rule

Jun 30Active

2024(30)

Bromate

Dec 31Resolved

Bromate

Dec 31Resolved