Counties with the fewest water health violations and highest water safety scores.
Clean drinking water is a fundamental quality-of-life factor that often goes unexamined until a crisis occurs. Our water quality score is derived from EPA Safe Drinking Water Information System (SDWIS) data, tracking health-based violations at water systems serving each county. These include violations for contaminants like lead, coliform bacteria, disinfection byproducts, and nitrates — substances with direct health implications. Counties scoring highest have water systems with clean compliance records and few or no health violations. Counties scoring lowest may have small, under-resourced water systems or aging infrastructure that struggles to meet federal standards. Water quality issues disproportionately affect rural communities and older cities. For homebuyers, these rankings highlight an often-overlooked factor in location decisions. Counties with poor water scores may require well water testing, filtration systems, or bottled water — ongoing costs that should factor into your total cost of living assessment.