Water Quality in California
Water hardness and contaminant data for 42 cities across California. Find your city below to see a detailed water quality profile.
42
Cities
177
Avg Hardness (PPM)
265
Hardest City (PPM)
California Cities by Water Hardness
| City | Hardness (PPM) | Level | PFAS (ppt) | Source |
|---|---|---|---|---|
| Lancaster | 265 | Extremely Hard | 6 | Groundwater, State Water Project |
| Palmdale | 250 | Extremely Hard | 5 | State Water Project, groundwater |
| Sunnyvale | 222 | Very Hard | 6 | SFPUC, Valley Water |
| Temecula | 220 | Very Hard | 8 | MWD imports, Vail Lake |
| Chula Vista | 216 | Very Hard | 8 | Colorado River imports |
| Concord | 215 | Very Hard | 7 | CCWD Los Vaqueros, EBMUD |
| Hayward | 214 | Very Hard | 7 | SFPUC Hetch Hetchy, ACWD |
| Fontana | 208 | Very Hard | 8 | State Water Project, groundwater |
| Long Beach | 204 | Very Hard | 8 | Colorado River, groundwater |
| Moreno Valley | 204 | Very Hard | 6 | EMWD imported + groundwater |
| Garden Grove | 204 | Very Hard | 6 | MWD imports, OC groundwater |
| Torrance | 203 | Very Hard | 9 | MWD imports, groundwater |
| Anaheim | 201 | Very Hard | 7 | MWD imports, OC groundwater |
| Escondido | 201 | Very Hard | 6 | Lake Dixon, MWD imports |
| San Diego | 200 | Very Hard | 10 | Imported + local reservoirs |
| Riverside | 200 | Very Hard | 7 | State Water Project, groundwater |
| Corona | 200 | Very Hard | 9 | Groundwater, MWD imports |
| Fremont | 192 | Very Hard | 6 | Hetch Hetchy + ACWD local |
| Rancho Cucamonga | 192 | Very Hard | 7 | Cucamonga Valley Water District |
| San Bernardino | 190 | Very Hard | 7 | Groundwater, State Water Project |
| Downey | 190 | Very Hard | 7 | Groundwater, MWD |
| Huntington Beach | 189 | Very Hard | 9 | MWD imports, OC groundwater |
| Santa Clarita | 188 | Very Hard | 8 | State Water Project, groundwater |
| San Jose | 183 | Very Hard | 8 | Delta imports, groundwater, Hetch Hetchy |
| Ontario | 183 | Very Hard | 8 | State Water Project, groundwater |
| Pasadena | 182 | Very Hard | 10 | Local wells, MWD imports |
| Los Angeles | 180 | Hard | 12 | Imported + Groundwater |
| Pomona | 180 | Very Hard | 9 | Three Valleys MWD |
| Santa Ana | 178 | Hard | 7 | MWD imports, OC groundwater |
| Murrieta | 177 | Hard | 7 | MWD imports, groundwater |
| Oxnard | 175 | Hard | 7 | Groundwater, State Water Project |
| Irvine | 173 | Hard | 8 | MWD imports, OC groundwater |
| Roseville | 169 | Hard | 4 | Folsom Lake, American River |
| Elk Grove | 154 | Hard | 4 | Sacramento River, groundwater |
| Modesto | 144 | Hard | 4 | Tuolumne River, groundwater |
| Visalia | 141 | Hard | 5 | Groundwater, Kaweah River |
| Bakersfield | 132 | Hard | 3 | Kern River, groundwater |
| Stockton | 129 | Hard | 5 | Surface water, groundwater |
| Fresno | 126 | Hard | 4 | Groundwater, Kings River |
| Daly City | 34 | Slightly Hard | 4 | SFPUC Hetch Hetchy |
| San Francisco | 21 | Slightly Hard | 3 | Hetch Hetchy (Yosemite) |
| Sacramento | 18 | Slightly Hard | 3 | American River, Sacramento River |