| WAUKESHA WATER UTILITY | 70,718 | 2,969 | Clean |
| BROOKFIELD WATER UTILITY | 29,070 | 504 | Detected |
| NEW BERLIN WATER UTILITY | 27,899 | 675 | Clean |
| MENOMONEE FALLS WW - SURFACE WATER | 23,867 | 87 | Clean |
| OCONOMOWOC WATERWORKS | 15,805 | 26 | Detected |
| SUSSEX VILLAGE HALL & WATER UTILITY | 11,750 | 1,254 | Detected |
| HARTLAND WATERWORKS | 9,212 | 21 | Detected |
| PEWAUKEE CITY WATER AND SEWER UTILITY | 8,671 | 467 | Detected |
| MUKWONAGO WATERWORKS | 8,190 | 284 | Clean |
| PEWAUKEE VILLAGE WATERWORKS | 8,166 | 175 | Clean |
| MUSKEGO WATER UTILITY | 8,150 | 108 | Detected |
| TOWN OF BROOKFIELD SAN DIST 4 | 6,419 | 216 | Detected |
| DOUSMAN WATER UTILITY | 2,350 | 129 | — |
| BUTLER WATERWORKS | 2,181 | 61 | — |
| PRAIRIE VILLAGE WATER TRUST | 2,100 | 253 | — |
| EAGLE WATERWORKS | 1,950 | 253 | — |
| WALES PICK N SAVE | 1,900 | 51 | — |
| KWIK TRIP #1108 | 1,810 | 0 | — |
| MENOMONEE FALLS WW - GROUNDWATER | 1,796 | 271 | — |
| KETTLE MORAINE HIGH SCHOOL & WALES ELEM SCHOOL | 1,670 | 14 | — |
| FLEET FARM MUSKEGO MAIN STORE | 1,585 | 0 | — |
| KWIK TRIP #973 | 1,404 | 0 | — |
| NEW BERLIN WEST MIDDLE HIGH SCHOOL | 1,380 | 330 | Detected |
| ELMBROOK MEMORIAL HOSPITAL | 1,250 | 169 | — |
| MCDONALDS VERNON | 1,250 | 118 | — |
| MERTON INTERMEDIATE & PRIMARY SCHOOL | 1,130 | 21 | — |
| PILGRIM PARK MIDDLE SCHOOL | 950 | 281 | — |
| KWIK TRIP 360 OCONOMOWOC | 906 | 0 | — |
| MILL CREEK ACADEMY | 886 | 2 | — |
| GENERAC POWER SYSTEMS INC | 875 | 8 | — |
| LAKE DENOON MIDDLE SCHOOL | 825 | 35 | — |
| CROSS POINT COMMUNITY CHURCH | 764 | 0 | — |
| LAKE MEADOWS WATER TRUST | 750 | 702 | — |
| HALE PARK MEADOWS | 720 | 179 | — |
| CHRIST LUTHERAN SCHOOL AND CHURCH | 704 | 202 | — |
| DURHAM MEADOWS WATER TRUST | 700 | 3 | — |
| ROLLING HILLS ELEMENTARY SCHL | 666 | 8 | — |
| WAUKESHA BIBLE CHURCH | 654 | 0 | — |
| ROSE GLEN ELEMENTARY | 652 | 50 | — |
| DAYSPRING BAPTIST CHURCH INC | 636 | 0 | — |
| LAKE COUNTRY SCHOOL | 623 | 110 | — |
| ST MARYS SCHOOL & ST MARYS PARISH | 606 | 95 | — |
| ELMBROOK- LAKE COUNTRY | 600 | 8 | — |
| DELAFIELD SQUARE | 587 | 10 | — |
| NRF VIII - AUTUMN GROVE LLC | 578 | 0 | — |
| DOTTIES HOME BAKERY & LIQUOR | 567 | 9 | — |
| PRAIRIE VIEW ELEMENTARY SCHOOL | 565 | 2 | — |
| ABUNDANT LIFE APOSTOLIC CHURCH | 543 | 114 | — |
| SECTION ELEMENTARY SCHOOL | 540 | 8 | — |
| RICHMOND SCHOOL | 533 | 5 | — |