Answering the question, "What an aerobic treatment unit looks like", is about like answering the question "What does a dog look like". They both come in different sizes, shapes, and colors. Most of them are burried except for risers which allow the system to be maintained. The photo on the left shows an ATU (aerobic treatment unit) with two fiberglass risers. This is a fairly typical looking installation before any landscaping has been done.
The photo on the right shows a dry ditch discharge. The pipes sticking up are part of one manufacturer's design for post aeration of effluent and are not necessarily required by Virginia regulations. Dry ditches are sometimes filled with stone, fenced, or otherwise designed to keep children, pets, and animals away from the treated effluent.
The photo above shows the outlet where the effluent leaves the system and enters the dry ditch. Note how clear the effluent is. This is effluent from a properly operating system. You'll have to take our word for it but there isn't any odor with this system. This effluent is absorbed into the soil in the dry ditch and returned to the environment.