An operator holding a Class D license works in a POTW with 0.080 mgd capacity using an Imhoff tank and stabilization ponds. Can this operator renew the Class D license?

• A. Yes
• B. No
• C. Only if upgrading to Class B
• D. Only with additional training

Answer: (A)

Licenses are tied to the maximum design flow a plant is allowed to treat. Renewal is allowed as long as the facility stays at or below that class’s design-capacity limit and the operator meets required continuing education. Here, the POTW’s capacity is 0.080 mgd, which is under the Class D limit (0.1 mgd). The treatment setup—Imhoff tank and stabilization ponds—describes the plant, but doesn’t push the facility beyond that limit. So the operator may renew the Class D license without upgrading. Additional training requirements exist for renewal, but upgrading would not be necessary unless the design capacity exceeded the Class D limit.