As Maintenance Supervisor of the Wastewater Department, Randy was facing some serious challenges with the existing bar screen equipment.

Question: What was the reason for the purchase of new bar screen equipment?
Randy: “We needed to replace the (existing) bar screen equipment because of all the problems. The (existing) bar screen equipment was extremely high maintenance. Once-a-week minor repairs, once-a-month major repairs. Lower sprockets on the old equipment were a real problem. I had a real problem keeping bushings in my lower sprockets because they were exposed to grit from being submerged in the influent flows. To fix it, we had to dewater the chamber (a twelve hour, four man operation), remove the chains, lay in the lower sump to remove the shaft and sprockets. The whole process required us to work under our confined space program.”

Question: In August of 1998 you switched out one of the old bar screen units and replaced it with one grinding unit, how did that work out for you?
Randy: “We only purchased one grinding unit at my suggestion. We had mechanical problems, and had to pull it several times, and it was causing other problems. It was grinding, but the pieces (rags, string) were still in the system. They would settle out in the bottom of our clarifiers, and plug our under-drain piping. Also, we were taking our primary pumps apart every two months and removing a six gallon plug that would completely block off our closed impellers. The stainless steel wear rings (on the pumps) were wearing out too, because of the ground pieces of rags and plastic. We’d get about five to six months on the wear rings.”