Wastewater Treatment Operator: Duties, Licensing, and Pay

A typical day: Much of a wastewater operator's job is keeping a living process healthy. Air is pumped into the incoming wastewater in large tanks called aeration basins. That air gives billions of microbes the oxygen they need to break down the waste. Microbes are tiny living things that are already in the water when it arrives.

The operator checks those basins during the day. The operator also puts a sample of the microbes under a microscope. The point is to see whether they look healthy and active. The operator then adjusts the flow rates. The microbes need enough food, but not so much that they are swamped. The operator collects samples of the effluent as well. Effluent is the treated water that leaves the plant. Every plant holds a discharge permit, which sets limits on what that water may carry. Lab tests on the samples show whether the water leaving the plant meets those limits. A hard rainstorm can push a surge of extra flow through the plant. Operators must act fast to keep the process steady.

Getting licensed: The path usually starts with a high school diploma. Next comes training on the job. A new worker is called an operator-in-training and works under a licensed operator. Every state also asks operators to pass a licensing exam. There is a separate exam for the wastewater side of the work. Each state sets its own license classes and names them in its own way. Texas, for example, uses Class D through Class A. The class depends on the size of the plant and on how many years the operator has worked. Some operators finish a community college program in wastewater or environmental technology. Many others learn the whole job on the plant floor.

Pay and outlook: Federal pay data counts wastewater operators in a larger group. That group is called water and wastewater treatment plant operators. As of May 2025, it earned a median of $60,020 per year. Pay spreads out widely around that middle figure. The 10th percentile was $39,110, meaning the lowest-paid tenth of operators earned less than that. The 90th percentile was $91,060, meaning the highest-paid tenth earned more than that.

The Bureau of Labor Statistics expects about 10,000 openings for operators each year from 2025 to 2035. All of them come from replacing workers who retire or change careers, since total jobs are projected to shrink slightly. About 131,000 people worked in the field in 2025.

Roughly one-third of the water workforce becomes retirement-eligible within the next decade. That means those workers will be old enough to retire. In 2016, only about 10 percent of water workers were 24 or younger, compared with 12.5 percent of all U.S. workers. That gap is one reason the field is hiring hard for new operators.

Discussion questions:

1. Look back at the Career Profile. Name two specific tasks a wastewater operator does during a typical day.

2. Suppose a plant has 12 operators. One-third of them are retirement-eligible within the next decade. How many of the 12 operators is that?

3. An operator starts at the 10th percentile pay of $39,110. That operator gains experience and moves up in license class. Pay reaches the median of $60,020. By about what percent did the operator's pay go up? Round to the nearest whole percent.

4. The field holds about 131,000 jobs and is expected to shrink slightly. Use the Career Profile to explain why it still has steady job openings each year.