Largest public system
- City of Shelby: TTHM (disinfection byproducts)
- 55 ppb
- As reported (2025); federal limit 80 ppb.
- City of Shelby, 2025
- City of Shelby: HAA5 (disinfection byproducts)
- 23 ppb
- As reported (2025); federal limit 60 ppb.
- City of Shelby, 2025
- City of Shelby: Lead (at sampled homes' taps)
- 0 ppb
- 90th percentile of homes sampled (2025); 0 sampled homes above the action level. The federal action level is 15 ppb.
- City of Shelby, 2025