| PA AMER WATER CO-PITTSBURGH | 686,000 | 28 | Detected |
| PITTSBURGH WATER & SEWER AUTH | 520,000 | 193 | Clean |
| WEST VIEW WATER AUTHORITY | 200,000 | 290 | Clean |
| WILKINSBURG-PENN JT WATER AUTH | 125,000 | 155 | Clean |
| HAMPTON SHALER WATER AUTHORITY | 61,949 | 74 | Detected |
| MONROEVILLE MUNICIPAL AUTH | 48,500 | 45 | Detected |
| OAKMONT WATER AUTHORITY | 39,901 | 26 | Detected |
| MOON TWP MUNI AUTH | 38,000 | 168 | Detected |
| WEST CNTY MUNI AUTH-MCKEESPORT | 32,644 | 110 | Clean |
| PLUM BORO MUNI AUTH | 27,500 | 50 | Clean |
| PITTSBURGH INTL AIRPORT | 26,915 | 43 | Detected |
| WESTERN ALLEGHENY COUNTY MUN A | 19,031 | 101 | Detected |
| FOX CHAPEL AUTH | 18,500 | 21 | Clean |
| ROBINSON TWP MUNI AUTH | 16,354 | 199 | Clean |
| HARRISON TWP WATER AUTH | 13,411 | 133 | Clean |
| FINDLAY TWP MUNICIPAL AUTH | 11,460 | 128 | Clean |
| RICHLAND TWP WATER AUTHORITY | 10,190 | 16 | Clean |
| UPMC PRESBYTERIAN | 8,200 | 47 | Clean |
| EDGEWORTH BORO MUNI AUTH | 7,781 | 23 | Clean |
| SEWICKLEY BORO WATER AUTH | 6,800 | 214 | Detected |
| NEVILLE TWP WATER DEPT | 6,750 | 34 | Clean |
| VA PITTSBURGH UD | 6,701 | 10 | Clean |
| CORAOPOLIS WATER & SEWER AUTH | 5,804 | 97 | Detected |
| DUQUESNE WATER DEPT | 5,565 | 136 | Clean |
| TARENTUM BORO WATER DEPT | 4,927 | 152 | Clean |
| UPMC MAGEE WOMENS HOSPITAL | 4,900 | 37 | Detected |
| UPMC SHADYSIDE HILLMAN CAMPUS | 4,750 | 52 | Clean |
| FAWN FRAZER JT WATER AUTH | 4,650 | 72 | Detected |
| UPMC MONTEFIORE | 4,500 | 36 | Clean |
| BRACKENRIDGE BORO WATER DEPT | 3,700 | 137 | Clean |
| SPRINGDALE BORO WATER DEPT | 3,405 | 249 | Detected |
| RESERVE TWP WATER DEPT | 3,204 | 48 | Clean |
| HARMAR TWP MUNI AUTH | 3,200 | 368 | — |
| ASPINWALL BORO WATER DEPT | 3,151 | 47 | — |
| VA HEALTHCARE SYSTEM HEINZ | 3,112 | 11 | — |
| UPMC WESTERN PSYCHIATRIC INST | 2,645 | 49 | — |
| ALLEGHENY GENERAL HOSPITAL | 2,595 | 0 | — |
| JEFFERSON HOSPITAL | 2,470 | 0 | — |
| BLAWNOX BORO WATER DEPT | 2,200 | 176 | — |
| ALEPPO TWP AUTH | 2,200 | 56 | — |
| EAST DEER TWP WATER DEPT | 2,000 | 110 | — |
| CHESWICK BORO WATER DEPT | 1,861 | 119 | — |
| BRADDOCK BORO WATER AUTH | 1,708 | 65 | — |
| TOWNSHIP OF SPRINGDALE | 1,600 | 88 | — |
| OAKDALE BORO WATER DEPT | 1,459 | 119 | — |
| AHN WEXFORD HOSPITAL | 1,072 | 0 | — |
| ALLEGHENY VALLEY HOSPITAL | 908 | 0 | — |
| DAVIDS DINER | 900 | 71 | — |
| VIRGINIA HILLS PA LLC | 843 | 0 | — |
| HERITAGE VALLEY SEWICKLEY | 750 | 0 | — |