5 cities covered
Colorado water quality and radon, by city
4 of 5 covered Colorado cities use chloramine in at least part of the system, and 0 have hard water. 53 of Colorado's 64 counties are EPA radon zone 1.
| City | Disinfectant | Hardness | Lead | PFAS | Radon |
|---|---|---|---|---|---|
| Denver | Chloramine | 5.7 gpg | 3.1 ppb | Not detected | Zone 1 |
| Colorado Springs | Chlorine | 2.1 gpg | 5.7 ppb | Not detected | Zone 1 |
| Aurora | Chloramine | 5.8 gpg | 2.5 ppb | Detected | Zone 1 |
| Lakewood | Chloramine | 5.7 gpg | 3.1 ppb | Not detected | Zone 1 |
| Thornton | Chloramine | 5.8 gpg | 2.3 ppb | PFOA, PFOS | Zone 1 |
Colorado radon zones
Zone 1 (highest)53 counties
Zone 211 counties
Zone 3 (lowest)0 counties