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Pennsylvania Water Quality
812
Utilities in database
11.3M
Residents served
30%
On private wells
3
Key contaminants tracked
Drinking Water in Pennsylvania
Pennsylvania has 812 community water systems serving approximately 11.3 million residents. Primary water sources include groundwater. The most commonly reported contaminants include disinfection byproducts, lead, nitrates. 30% of Pennsylvania residents rely on private wells. DEP holds primary enforcement authority under the Safe Drinking Water Act.
Utilities in Pennsylvania
Top 20 of 812 by populationPhiladelphia Water Department
PA1510001 · 1,600,000 served
Aqua Pa Main System
PA1460073 · 822,600 served
Pa Amer Water Co-pittsburgh
PA5020039 · 686,000 served
Pittsburgh Water & Sewer Auth
PA5020038 · 520,000 served
Erie City Water Authority
PA6250028 · 220,001 served
York Water Co
PA7670100 · 206,762 served
West View Water Authority
PA5020043 · 200,000 served
Mawc Sweeney Plant
PA5650032 · 143,000 served
Chester Water Authority
PA1230004 · 140,437 served
Pa Amer Water Co Lake Scranton
PA2359008 · 134,570 served
Mawc Yough Plant
PA5260036 · 133,000 served
Wilkinsburg-penn Jt Water Auth
PA5020056 · 125,000 served
City of Lancaster
PA7360058 · 120,000 served
Lca Allentown Division
PA3390024 · 118,000 served
City of Bethlehem
PA3480046 · 117,259 served
Veolia Water
PA7220015 · 110,000 served
Pa American Water Co West
PA7210029 · 105,127 served
Easton Area Water System
PA3480050 · 96,867 served
Reading Area Water Authority
PA3060059 · 95,100 served
North Penn Water Authority
PA1460034 · 91,941 served
Key Contaminant Concerns in Pennsylvania
Lead
Lead is a naturally occurring heavy metal that was widely used in plumbing infrastructure until it was banned for new installations in 1986. An estimated 9.2 million lead service lines still connect homes to public water mains across the United States, along with millions of homes with lead solder in their internal plumbing.
Nitrates
Nitrate (NO₃⁻) is a nitrogen-containing compound that forms naturally through the decomposition of organic matter. At elevated concentrations — almost always from human activity — nitrate interferes with the blood's ability to carry oxygen. The United States produces over 23 million tons of nitrogen fertilizer annually, making agricultural runoff the dominant source of nitrate contamination.
DBPs
When utilities add chlorine to water to kill pathogens, it reacts with dissolved organic matter — leaves, algae, soil — to produce disinfection byproducts (DBPs). Over 600 DBPs have been identified. The EPA regulates two groups: total trihalomethanes (TTHMs, including chloroform) and haloacetic acids (HAA5). DBP levels tend to be highest in surface water systems and in warm months when organic matter is elevated.
Pennsylvania Water FAQs
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Data source: Utility data from EPA SDWIS. 812 active community water systems ingested. CCR contaminant data ingestion in progress.
Last updated: 2026-04-18