Water Quality in PORTERVILLE, CA (93257)

EPA violation data for public water systems serving ZIP code 93257.

102

Total Violations

Health-Based

Monitoring / Reporting

Resolved

What does this mean?

86 of 102 violations have been resolved. 49 are health-based violations, meaning contaminant levels exceeded federal safety limits. The remaining 53 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: 154 Population served: 89,033

Violations Detail (102 total)

Contaminant	Category	MCL Limit	Measured	Date	Status	Health Effects
Groundwater Rule	Health-Based	N/A	N/A	Sep 18, 2025	Active	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2025	Resolved	N/A
Chlorine	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	Eye and nose irritation; stomach discomfort
Arsenic	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	Skin damage; circulatory system problems; increased risk of cancer
Nitrate	Health-Based	N/A	23.6	Jun 30, 2025	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	Jun 30, 2025	Resolved	N/A
Groundwater Rule	Health-Based	N/A	N/A	Jun 29, 2025	Active	N/A
Groundwater Rule	Health-Based	N/A	N/A	Jun 29, 2025	Active	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	May 31, 2025	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	May 31, 2025	Resolved	N/A
Nitrate	Health-Based	N/A	25.3	Mar 31, 2025	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Health-Based	N/A	10.8	Mar 31, 2025	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Unknown	Monitoring	N/A	N/A	Mar 31, 2025	Resolved	N/A
Unknown	Monitoring	N/A	N/A	Mar 31, 2025	Resolved	N/A
Groundwater Rule	Health-Based	N/A	N/A	Feb 13, 2025	Active	N/A
Groundwater Rule	Health-Based	N/A	N/A	Feb 13, 2025	Active	N/A
Nitrate	Monitoring	N/A	N/A	Dec 31, 2024	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Total Haloacetic Acids (HAA5)	Monitoring	N/A	N/A	Dec 31, 2024	Resolved	N/A
Nitrate	Monitoring	N/A	N/A	Dec 31, 2024	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, 2024	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
TTHM	Monitoring	N/A	N/A	Dec 31, 2024	Resolved	N/A
Nitrate	Health-Based	N/A	24.5	Dec 31, 2024	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
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
Nitrate	Monitoring	N/A	N/A	Sep 30, 2024	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Sep 30, 2024	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Sep 30, 2024	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Arsenic	Monitoring	N/A	N/A	Sep 30, 2024	Resolved	Skin damage; circulatory system problems; increased risk of cancer
Nitrate	Health-Based	N/A	22.4	Sep 30, 2024	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Health-Based	N/A	10.3	Sep 30, 2024	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Surface Water Treatment Rule	Monitoring	N/A	N/A	Aug 31, 2024	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Aug 31, 2024	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Aug 31, 2024	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Aug 31, 2024	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Aug 31, 2024	Resolved	N/A
Surface Water Treatment Rule	Monitoring	N/A	N/A	Jul 31, 2024	Resolved	N/A
Nitrate	Health-Based	N/A	23.9	Jun 30, 2024	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Health-Based	N/A	11.2	Jun 30, 2024	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Revised Total Coliform Rule	Health-Based	N/A	N/A	Mar 31, 2024	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Mar 31, 2024	Resolved	N/A
Nitrate	Health-Based	N/A	17.9	Mar 31, 2024	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Health-Based	N/A	11	Mar 31, 2024	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Health-Based	N/A	21.3	Dec 31, 2023	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Health-Based	N/A	11.1	Dec 31, 2023	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	Nov 30, 2023	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Nov 30, 2023	Resolved	N/A
Chlorine	Monitoring	N/A	N/A	Sep 30, 2023	Resolved	Eye and nose irritation; stomach discomfort
Nitrate	Health-Based	N/A	17.7	Sep 30, 2023	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Health-Based	N/A	11	Sep 30, 2023	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, 2023	Resolved	N/A
Nitrate	Health-Based	N/A	15.9	Jun 30, 2023	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Health-Based	N/A	10.8	Jun 30, 2023	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Unknown	Monitoring	N/A	N/A	May 31, 2023	Resolved	N/A
Unknown	Monitoring	N/A	N/A	May 31, 2023	Resolved	N/A
TTHM	Monitoring	N/A	N/A	Mar 31, 2023	Resolved	N/A
Total Haloacetic Acids (HAA5)	Monitoring	N/A	N/A	Mar 31, 2023	Resolved	N/A
Nitrate	Health-Based	N/A	17.9	Mar 31, 2023	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Surface Water Treatment Rule	Monitoring	N/A	N/A	Feb 28, 2023	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Feb 28, 2023	Resolved	N/A
Public Notice	Monitoring	N/A	N/A	Feb 28, 2023	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Feb 28, 2023	Resolved	N/A
Public Notice	Monitoring	N/A	N/A	Feb 28, 2023	Resolved	N/A
Public Notice	Monitoring	N/A	N/A	Jan 31, 2023	Active	N/A
Surface Water Treatment Rule	Monitoring	N/A	N/A	Jan 31, 2023	Resolved	N/A
Surface Water Treatment Rule	Health-Based	N/A	N/A	Jan 31, 2023	Resolved	N/A
Chlorine	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Eye and nose irritation; stomach discomfort
Nitrate	Health-Based	N/A	16	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Health-Based	N/A	10.7	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Total Haloacetic Acids (HAA5)	Monitoring	N/A	N/A	Dec 31, 2022	Active	N/A
TTHM	Monitoring	N/A	N/A	Dec 31, 2022	Active	N/A
Ethylbenzene	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Nitrate	Health-Based	N/A	14.1	Sep 30, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Health-Based	N/A	13.8	Jun 30, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Health-Based	N/A	10.55	Jun 30, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Jun 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Jun 30, 2022	Resolved	N/A
2,3,7,8-TCDD	Monitoring	N/A	N/A	Mar 31, 2022	Resolved	N/A
Nitrate	Health-Based	N/A	15	Mar 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
2,3,7,8-TCDD	Monitoring	N/A	N/A	Dec 31, 2021	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
2,3,7,8-TCDD	Monitoring	N/A	N/A	Sep 30, 2021	Resolved	N/A
Combined Radium (-226 and -228)	Monitoring	N/A	N/A	Sep 30, 2021	Resolved	N/A
Nitrate	Health-Based	N/A	12.8	Sep 30, 2021	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, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2021	Resolved	N/A
Nitrate	Health-Based	N/A	12.7	Jun 30, 2021	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Health-Based	N/A	19.35	Jun 30, 2021	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Health-Based	N/A	19.35	Jun 30, 2021	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	Apr 30, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Apr 30, 2021	Resolved	N/A
Nitrate	Health-Based	N/A	11.7	Mar 31, 2021	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Health-Based	N/A	17.45	Mar 31, 2021	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Health-Based	N/A	17.45	Mar 31, 2021	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath

Lead & Copper Levels

Violation Timeline

2025(16)

Groundwater Rule

Sep 18Active

Revised Total Coliform Rule

Jul 31Resolved

Chlorine

Jun 30Resolved

Arsenic

Jun 30Resolved

Nitrate

Jun 30Resolved

Revised Total Coliform Rule

Jun 30Resolved

Groundwater Rule

Jun 29Active

Groundwater Rule

Jun 29Active

Revised Total Coliform Rule

May 31Resolved

Revised Total Coliform Rule

May 31Resolved

Nitrate

Mar 31Resolved

Nitrate

Mar 31Resolved

Unknown contaminant

Mar 31Resolved

Unknown contaminant

Mar 31Resolved

Groundwater Rule

Feb 13Active

Groundwater Rule

Feb 13Active

2024(32)

Nitrate

Dec 31Resolved

Total Haloacetic Acids (HAA5)

Dec 31Resolved

Nitrate

Dec 31Resolved

Nitrate

Dec 31Resolved

TTHM

Dec 31Resolved

Nitrate

Dec 31Resolved