Mississippi Water Supply Operator Certification: Class D Through Class A
Certification Structure
Mississippi water treatment operators are certified by the Mississippi State Department of Health (MSDH), Bureau of Public Water Supply, in four classes graded by treatment process complexity rather than simple flow or population thresholds:
- Class D — systems with no treatment beyond chlorination and/or fluoridation, or direct chemical feed such as polyphosphate
- Class C — systems with aeration, pH adjustment, corrosion control, or closed pressure filtration (including zeolite softening or iron removal)
- Class B — systems with two or more Class-C-type facilities of different types, iron/manganese removal breaking pressure or requiring flocculation/sedimentation, membrane filtration, or ion exchange treatment
- Class A — systems with surface water treatment and