Pennsylvania water quality
Pennsylvania has 7,341 active public water systems (22,494 on file total), 1,782 of them graded by TapGraded.
Grade distribution
Biggest water systems
PHILADELPHIA WATER DEPARTMENT
PHILADELPHIA, PA · 1,600,000 served
AQUA PA MAIN SYSTEM
BRYN MAWR, PA · 822,600 served
PA AMER WATER CO-PITTSBURGH
ELRAMA, PA · 686,000 served
PITTSBURGH WATER & SEWER AUTH
PITTSBURGH, PA · 520,000 served
ERIE CITY WATER AUTHORITY
ERIE, PA · 220,001 served
YORK WATER CO
YORK, PA · 206,762 served
WEST VIEW WATER AUTHORITY
PITTSBURGH, PA · 200,000 served
MAWC SWEENEY PLANT
GREENSBURG, PA · 143,000 served
CHESTER WATER AUTHORITY
CHESTER, PA · 140,437 served
PA AMER WATER CO LAKE SCRANTON
WILKES BARRE, PA · 137,142 served
Lowest-graded systems
Active, graded systems serving at least 10,000 people, ordered by lowest Tap Grade first.
BCWSA MAIN LOWER SOUTH
WARRINGTON, PA · 52,621 served
TRI CNTY JT MUNI AUTH
FREDERICKTOWN, PA · 10,100 served
MUN WATER AUTH OF ALIQUIPPA
ALIQUIPPA, PA · 15,685 served
UPPER SOUTHAMPTON MUN AUTH
SOUTHAMPTON, PA · 16,000 served
WESTERN ALLEGHENY COUNTY MUN A
OAKDALE, PA · 19,031 served
EAST HEMPFIELD WATER AUTH
LANDISVILLE, PA · 20,988 served
E STROUDSBURG BORO WATER DEPT
EAST STROUDSBURG, PA · 13,000 served
CITY OF LANCASTER
LANCASTER, PA · 120,000 served
AQUA PA MAIN SYSTEM
BRYN MAWR, PA · 822,600 served
PHOENIXVILLE WATER DEPT
PHOENIXVILLE, PA · 16,599 served
Cities in Pennsylvania
Source: EPA SDWIS/ECHO · Data as of 2026Q2