- EPA's UCMR 5 testing looked for 30 contaminants here and found 7.
- Lithium: found in 8 of 8 samples, average 25.1 µg/L, highest 60 µg/L (EPA UCMR 5 testing, Dec 2023–Sep 2024)
- PFBS (a PFAS): found in 4 of 8 samples, average 5 ppt, highest 11 ppt (EPA UCMR 5 testing, Dec 2023–Sep 2024)
- PFHxS (a PFAS): found in 4 of 8 samples, average 2.1 ppt, highest 5.5 ppt (EPA UCMR 5 testing, Dec 2023–Sep 2024)
- PFOS (a PFAS): found in 3 of 8 samples, average 2.1 ppt, highest 6.8 ppt (EPA UCMR 5 testing, Dec 2023–Sep 2024)
- PFPeA (a PFAS): found in 4 of 8 samples, average 2 ppt, highest 4.5 ppt (EPA UCMR 5 testing, Dec 2023–Sep 2024)
- PFOA (a PFAS): found in 3 of 8 samples, average 1.8 ppt, highest 5.8 ppt (EPA UCMR 5 testing, Dec 2023–Sep 2024)
- PFHxA (a PFAS): found in 3 of 8 samples, average 1.3 ppt, highest 3.5 ppt (EPA UCMR 5 testing, Dec 2023–Sep 2024)
- Lead, 90th percentile: 0 ppb at the latest result in EPA records for a monitoring period that ran on or after July 1, 2021, at or below EPA's 15 ppb action level (EPA SDWIS, monitoring period Jan 1, 2024–Dec 31, 2026). The 90th percentile is a system-wide measure from homes sampled under EPA's lead rule; it isn't a result for your home.
Public EPA test results
Can you drink Arroyo Grande tap water? What EPA records show
EPA CA4010001 · serves San Luis Obispo County, CA · about 17,963 people (EPA SDWIS)
This report shows EPA's federal records for this water system: UCMR 5 testing, lead testing and violations. It isn't a test of the water at your tap, and it has no Water Score.
Public EPA test results
City of Arroyo Grande Utilities Division (EPA CA4010001)
EPA data as of October 14, 2026. For Arroyo Grande's main utility, City of Arroyo Grande Utilities Division: We found no health-based violations in EPA's records for this system (CA4010001) since July 1, 2021, as of October 14, 2026. EPA's UCMR 5 testing looked for 30 contaminants here and found 7.
What EPA records show for City of Arroyo Grande Utilities Division, as of October 14, 2026
We found no health-based violations in EPA's records for this system (CA4010001) since July 1, 2021, as of October 14, 2026.
Source: EPA ECHO record for City of Arroyo Grande Utilities Division (SDWIS). Data as of October 14, 2026.
Lead, 90th percentile: 0 ppb at the latest result in EPA records for a monitoring period that ran on or after July 1, 2021, at or below EPA's 15 ppb action level (EPA SDWIS, monitoring period Jan 1, 2024–Dec 31, 2026). The 90th percentile is a system-wide measure from homes sampled under EPA's lead rule; it isn't a result for your home.
EPA's UCMR 5 testing looked for 30 contaminants here and found 7.
Source: EPA records (SDWIS, UCMR 5). SDWIS: data as of Oct 14, 2026. EPA UCMR 5 data, samples through June 2026.
Your water bill names your utility.
Does City of Arroyo Grande Utilities Division use chloramine?
We didn't find chloramine in City of Arroyo Grande Utilities Division's EPA treatment records. That's not a complete list; your utility's annual water quality report says which disinfectant it uses.