San Dimas

San Dimas, CA receives a water quality score of 93/100 (Grade A) based on EPA Safe Drinking Water Information System (SDWIS) compliance data for 8 public water systems serving the area.

San Dimas's water quality is above the national average, with strong compliance records and low contaminant levels. Residents generally receive clean, safe tap water that meets EPA standards.

San Dimas's score of 93 is 4 points above the California state average of 89, and above the nationwide average of roughly 78/100 across all U.S. states.

Prospective homebuyers looking at the mid-size city of San Dimas, California, will find reassuring water quality, as the community's supply consistently performs at an exceptional level across its eight distinct water systems. This reliable performance is particularly notable given the regional challenges of the West Coast, where water systems must evaluate varied local geology alongside the pressures of nearby agricultural hubs and major urban centers. For everyday residents, this robust network maintains reliable compliance, ensuring clean and well-managed tap water for all household needs.

Water quality data is sourced from the U.S. EPA SDWIS database and updated quarterly. Learn about our scoring methodology → Read our California water quality rankings report →