Foley, AL

Recently, the Riviera staff upgraded the older units with new aeration equipment, mixers, and probes. "We gutted the older ditches," says Kibler. "We started from scratch and performed the modifications ourselves with the help of our engineering staff and superintendent Richard Peterson." It took about six months, during which flow was diverted to the other ditches that remained in operation.

"The aeration plumbing tubes were in bad shape," Kibler says. "Corrosion of the galvanized plumbing resulted in inadequate aeration, and the handheld meter was giving us inaccurate DO readings. We contracted out the concrete removal and all the electrical installation, but our staff did everything else, including the process development work."

BETTER LOGIC
The ditches are now equipped with rotary brush surface aerators (S&N Airoflo) and new probes (Insite) that include ORP monitoring so the ditches can be run as aerobic or anoxic zones to achieve total nitrogen removal.