Water Quality in ARROYO GRANDE, CA (93420)

EPA violation data for public water systems serving ZIP code 93420.

Total Violations

Health-Based

Monitoring / Reporting

Resolved

What does this mean?

72 of 77 violations have been resolved. 33 are health-based violations, meaning contaminant levels exceeded federal safety limits. The remaining 44 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: 36 Population served: 21,186

Violations Detail (77 total)

Contaminant	Category	MCL Limit	Measured	Date	Status	Health Effects
Nitrate	Health-Based	N/A	11	Jun 30, 2025	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Selenium	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
Selenium	Health-Based	N/A	61	Jun 30, 2025	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
Revised Total Coliform Rule	Monitoring	N/A	N/A	Apr 30, 2025	Resolved	N/A
Nitrate	Health-Based	N/A	12	Mar 31, 2025	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Selenium	Health-Based	N/A	61	Mar 31, 2025	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
Nitrate	Health-Based	N/A	19	Dec 31, 2024	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Selenium	Monitoring	N/A	N/A	Dec 31, 2024	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
Selenium	Health-Based	N/A	61	Dec 31, 2024	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
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
Nitrate	Health-Based	N/A	19	Sep 30, 2024	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Selenium	Monitoring	N/A	N/A	Sep 30, 2024	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
Selenium	Health-Based	N/A	54	Sep 30, 2024	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 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
Nitrate	Health-Based	N/A	11	Jun 30, 2024	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Selenium	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
Selenium	Health-Based	N/A	54	Jun 30, 2024	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
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
Selenium	Monitoring	N/A	N/A	Mar 31, 2024	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
Selenium	Health-Based	N/A	54	Mar 31, 2024	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
Revised Total Coliform Rule	Health-Based	N/A	N/A	Feb 29, 2024	Resolved	N/A
Nitrate	Health-Based	N/A	11	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, 2023	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Health-Based	N/A	16	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	16	Dec 31, 2023	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Selenium	Health-Based	N/A	54	Dec 31, 2023	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
Revised Total Coliform Rule	Monitoring	N/A	N/A	Dec 31, 2023	Resolved	N/A
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
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2023	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2023	Resolved	N/A
Selenium	Health-Based	N/A	54	Sep 30, 2023	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
Nitrate	Monitoring	N/A	N/A	Jun 30, 2023	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Selenium	Health-Based	N/A	54	Jun 30, 2023	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
Nitrate	Health-Based	N/A	11	Mar 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	Mar 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	Mar 31, 2023	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Selenium	Health-Based	N/A	54	Mar 31, 2023	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
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
Selenium	Health-Based	N/A	54	Dec 31, 2022	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
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	Sep 30, 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	Sep 30, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Selenium	Health-Based	N/A	54	Sep 30, 2022	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
Nitrate	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Selenium	Health-Based	N/A	0.054	Jun 30, 2022	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
Selenium	Health-Based	N/A	54	Mar 31, 2022	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
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
Selenium	Health-Based	N/A	54	Dec 31, 2021	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
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
Nitrate	Monitoring	N/A	N/A	Sep 30, 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
Selenium	Health-Based	N/A	54	Sep 30, 2021	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
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
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
Nitrate	Monitoring	N/A	N/A	Jun 30, 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	Jun 30, 2021	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Selenium	Health-Based	N/A	69	Jun 30, 2021	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems
Nitrate	Monitoring	N/A	N/A	May 24, 2021	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Selenium	Health-Based	N/A	60	Apr 4, 2021	Resolved	Hair or fingernail loss; numbness in fingers or toes; circulatory problems

Lead & Copper Levels

Violation Timeline

2025(6)

Nitrate

Jun 30Resolved

Selenium

Jun 30Resolved

Selenium

Jun 30Resolved

Revised Total Coliform Rule

Apr 30Resolved

Nitrate

Mar 31Resolved

Selenium

Mar 31Resolved

2024(20)

Nitrate

Dec 31Resolved

Selenium

Dec 31Resolved

Selenium

Dec 31Resolved

LEAD AND COPPER RULE REVISIONS

Oct 16Active

LEAD AND COPPER RULE REVISIONS

Oct 16Active

LEAD AND COPPER RULE REVISIONS

Oct 16Active

LEAD AND COPPER RULE REVISIONS

Oct 16Active

Nitrate

Sep 30Resolved

Selenium

Sep 30Resolved

Selenium

Sep 30Resolved

Lead and Copper Rule

Sep 30Active

Lead and Copper Rule

Sep 30Resolved

Lead and Copper Rule

Sep 30Resolved

Nitrate

Jun 30Resolved

Selenium

Jun 30Resolved

Selenium

Jun 30Resolved

Nitrate

Mar 31Resolved

Selenium

Mar 31Resolved

Selenium

Mar 31Resolved

Revised Total Coliform Rule

Feb 29Resolved

How Does This Compare?

ARROYO GRANDE (93420) has 77 recorded violations, including 33 health-based. 5 remain unresolved. Consider testing your tap water independently for added peace of mind.

Recommended Water Filters

Based on the contaminants detected in your area, these filter types may help improve your water quality.

Reverse Osmosis System

Highly effective at removing heavy metals, dissolved solids, and a wide range of contaminants. Recommended for homes with lead or arsenic concerns.

Targets:Lead, Copper, Arsenic, Mercury, Cadmium

Look for:NSF/ANSI 58 certified

NSF Certified Products → EPA Safe Drinking Water Guide →

UV Water Purifier

Uses ultraviolet light to neutralize bacteria, viruses, and parasites without chemicals. Ideal for homes with microbial contamination concerns.

Targets:E. coli, Coliform, Giardia, Cryptosporidium

Look for:NSF/ANSI 55 (Class A) certified

NSF Certified Products → EPA Safe Drinking Water Guide →

Always look for filters certified by NSF International for the specific contaminants you want to remove.

Water Quality in ARROYO GRANDE, CA (93420)

What does this mean?

Violations Detail (77 total)

Lead & Copper Levels

Violation Timeline

2025(6)

2024(20)

2023(17)

2022(15)

2021(19)

How Does This Compare?

Recommended Water Filters

Reverse Osmosis System

UV Water Purifier

Nearby ZIP Codes

Check Another ZIP Code