Jefferson Hills Water Hardness & Quality Report (2026)

The Jefferson Hills Municipal Authority supplies water to roughly 12,000 customers across Jefferson Hills Borough, South Park Township, and sections of Baldwin and Union Townships in Allegheny County, Pennsylvania. Their water comes from a blend of sources, including the South Park Reservoir and local wells tapping into underground aquifers. Water treatment takes place at the authority's own plant, where processes like filtration and chlorine disinfection are used before the water travels through more than 100 miles of pipes to reach homes.

The water originates in the Monongahela River watershed, part of the Allegheny Plateau. Beneath the surface lie Pennsylvanian-age bedrock formations such as the Conemaugh Formation, which contains limestone and shale layers. When water interacts with these carbonate-rich rocks, it dissolves minerals like calcium and magnesium, leading to the moderately hard water characteristic of this region. Aquifers within Pottsville sandstone also contribute to the water's mineral content, influenced by the karst terrain and local precipitation.

This moderately hard water can lead to scale buildup in appliances like water heaters, dishwashers, and washing machines, potentially shortening their lifespan and reducing efficiency. Homeowners often notice white residue on fixtures and spots on glassware. Regular cleaning with vinegar on faucets and coffee makers, along with annual flushing of hot water tanks, can help manage this. For those experiencing frequent issues, installing a water softener is a good idea to protect appliances and improve cleaning performance. The water's pH typically ranges from 7.5 to 8.5, and recent tests show good compliance with lead and copper regulations.