| SANTA CRUZ WATER DEPARTMENT | 94,626 | 15 | Detected |
| WATSONVILLE, CITY OF | 65,231 | 2 | Detected |
| SOQUEL CREEK WATER DISTRICT | 40,809 | 4 | Detected |
| SAN LORENZO VALLEY WATER DIST | 21,145 | 20 | Detected |
| CABRILLO COLLEGE | 12,000 | 7 | Detected |
| SCOTTS VALLEY WATER DISTRICT | 11,197 | 21 | Detected |
| SLVWD - FELTON WATER SYSTEM | 4,340 | 19 | Clean |
| CENTRAL WATER DISTRICT | 2,726 | 8 | — |
| APTOS HIGH SCHOOL | 1,348 | 14 | — |
| MISSION SPRINGS CONFERENCE CENTER | 1,310 | 35 | — |
| MT. HERMON ASSOCIATION, INC. | 1,176 | 7 | — |
| CSP- KIRKWOOD ENTRANCE | 1,154 | 0 | — |
| BIG BASIN WATER COMPANY | 1,120 | 102 | — |
| FOREST LAKES MWC | 1,067 | 38 | — |
| MONTE VISTA CHRISTIAN SCHOOL | 1,051 | 19 | — |
| ALIANZA CHARTER SCHOOL/WCSA | 670 | 17 | — |
| CSP - RANCHO DEL OSO | 669 | 20 | — |
| TROUT GULCH MUTUAL WATER COMPANY | 614 | 23 | Detected |
| SEVENTH DAY ADVENTIST CAMP | 578 | 12 | — |
| SANTA CRUZ COUNTY FAIRGROUNDS | 550 | 14 | — |
| MYSTERY SPOT SNACK SHACK | 500 | 6 | — |
| SUMMIT WEST MUTUAL WATER CO. | 481 | 41 | — |
| BUENA VISTA MIGRANT CENTER | 455 | 18 | — |
| VILLA DEL MONTE MWC | 419 | 30 | — |
| LAS CUMBRES MUTUAL WATER CO | 402 | 249 | — |
| MONTEREY BAY ACADEMY | 400 | 22 | — |
| FOREST SPRINGS | 385 | 267 | — |
| SAN ANDREAS MUTUAL WATER CO | 378 | 4 | — |
| DAVENPORT COUNTY SANITATION | 350 | 27 | — |
| BOULDER CREEK SCOUT RESERV. | 302 | 13 | — |
| MOUNTAIN ELEMENTARY SCHOOL | 240 | 11 | — |
| KENNOLYN CAMP | 239 | 26 | — |
| ROUNTREE FACILITY(PREV. SHERIFF'S REHAB) | 235 | 21 | — |
| MOUNTAIN SUMMIT MUTUAL WATER SYSTEM | 223 | 16 | — |
| RIDGE MUTUAL WATER COMPANY | 213 | 11 | — |
| GIZDICH HOME RANCH | 213 | 6 | — |
| PURESOURCE WATER, INC | 206 | 39 | — |
| RANCHO SAN ANDREAS | 200 | 22 | — |
| ROARING CAMP RAILROAD INC | 193 | 35 | — |
| SANTA CRUZ WALDORF SCHOOL | 190 | 18 | — |
| FERN GROVE WATER CLUB | 187 | 20 | — |
| BIG REDWOOD PARK WATER | 182 | 47 | — |
| SUNSET BEACH MUTUAL WATER CO | 182 | 7 | — |
| LA MADRONA ATHLETIC CLUB | 172 | 6 | — |
| MOUNT MADONNA CENTER | 170 | 18 | — |
| RENAISSANCE HIGH SCHOOL | 166 | 21 | — |
| KOINONIA CONFERENCE GROUNDS | 166 | 47 | — |
| BONNY DOON SCHOOL | 160 | 12 | — |
| CAMP CHESEBROUGH | 155 | 18 | — |
| SUMMIT MUTUAL WATER COMPANY | 152 | 51 | — |