West Mifflin Water Hardness & Quality Report (2026)

West Mifflin, Pennsylvania, is served by the Municipal Authority of West Mifflin (MAWM), providing water to Allegheny County residents in the borough and surrounding areas. Primary sources include surface water from the Monongahela River via interconnections with the Pittsburgh Water and Sewer Authority (PWSA), supplemented by local groundwater wells tapping Appalachian aquifers. Treatment occurs at PWSA's Aspinwall and Braddock facilities, with distribution through MAWM infrastructure. The system serves approximately 20,000 customers across 14 square miles.

The supply originates in the Monongahela River watershed, part of the larger Ohio River basin within the Allegheny Plateau physiographic province. Underlying geology features Pennsylvanian-age Conemaugh Group formations, including Glenshaw Formation sandstones, shales, and limestone lenses that dissolve to impart minerals. This geology yields a hard supply with elevated calcium and magnesium, contrasting with softer glacial waters in northern Pennsylvania; aquifer recharge through fractured bedrock further enhances mineral content.

Hard water promotes scale buildup in pipes, water heaters, dishwashers, and washing machines, reducing efficiency and lifespan — appliances may show 20–30% higher energy use. Regular vinegar descaling, scale-inhibiting filters, or a whole-home water softener are recommended for households noticing spots on dishes, dry skin, or soap scum. PWSA reports pH 7.5–8.5, compliant with EPA standards; the lead/copper rule is met via corrosion control with orthophosphate, with 90th percentile copper below 1.3 mg/L. No recent PFAS exceedances noted; treatment includes coagulation, filtration, UV, and chloramination.