City of Gridley

Water Quality Snapshot: City of Gridley

City of Gridley is a local-owned community water system that delivers drinking water to 7,269 residents in Gridley, California (Butte County) through 2,282 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 11 total violations for this system , of which 7 (64%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 2 monitoring and reporting violations are on file. The most recent violation on record dates to 2024.

The most frequently cited contaminant at this system is Arsenic, recorded in 4 violations (MCL, health-based). Under EPA's UCMR5 PFAS monitoring program, 6 PFAS compounds were detected in samples collected from this system, with a maximum reported concentration of 12.8 ppt (parts per trillion). PFAS are persistent synthetic chemicals linked to health effects at very low exposure levels.

Across California, EPA tracks 7,249 public water systems serving 42,404,883 people, with 153,308 cumulative violations and 63,983 health-based violations on record. About 89% of systems in the state carry at least one violation, and state-wide the average per system is 21.1 violations. Statewide, 447 of 694 UCMR5-tested systems have reported PFAS detections (64.4%).

City of Gridley's 11 violations sit below the California average.

All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.