Montana Wastewater Treatment: Class 3C-1C Operator Guide
Certification Structure
Montana DEQ certifies municipal wastewater treatment operators in three main classes: Class 3C (lowest) through Class 1C (highest), with the "C" designator distinguishing this track from the "A" (distribution) and "B" (water treatment) tracks under the same Public Water Supply Bureau program. Separate specialized credentials exist for industrial dischargers (D series) and on-site/package systems (E series), which are outside this core municipal ladder. Certificates run on a 36-month renewal cycle, with advancement gated on qualifying experience plus the next class's exam.
Lagoon Systems and Rural Treatment
Montana's low population density means a large share of small municipal wastewater systems rely on lagoon-based treatment rather than mechanical plants — lagoons are well suited to