Ada County Water Quality

Ada County, Idaho has a water quality grade of C with a score of 55.6/100, based on EPA Safe Drinking Water Information System data. The county has 50 health-based drinking water violations on record.

Ada County has 50 health-based drinking water violations recorded by the EPA. Health-based violations indicate instances where contaminant levels exceeded EPA Maximum Contaminant Levels (MCLs). Violations may have been resolved — check with your local water utility for current status.

Ada County's water quality score of 55.6/100 is higher than the Idaho state average of 32.6. The average water quality grade across Idaho is F, based on data from 44 counties with available water quality data.

Based on EPA data, Ada County has a water quality grade of C (55.6/100). This indicates moderate water quality. Some violations have been recorded but overall compliance is maintained. For the most up-to-date information, contact your local water utility or review your Consumer Confidence Report (CCR).

Ada County has 50 health-based drinking water violations on record from the EPA SDWIS database. A higher violation count can result from aging infrastructure, underfunded water utilities, agricultural runoff contamination, or industrial pollution. Counties with more water systems may also see more violations simply due to scale. Residents concerned about water quality should consider independent water testing and home filtration systems.

Ada County ranks #7 out of 44 counties in Idaho by water quality score (1 = best). With a score of 55.6/100, it falls in the top third of counties statewide. Rankings are based on EPA Safe Drinking Water Information System (SDWIS) data including health-based violations and compliance records.