darthsoilsguy2
Geotechnical
An RSF has been operating for 20 years. It's for a neighborhood system and treats an average of 10,000 metered gals/day. We took it offline for work on the tank and hauled away the sewage. Before the work, the sand filter lab results had been taking both BOD and TSS from around approx 200-300 mg/l influent down to +/- 5 at the filter effluent. Our first lab test was 50 days after the system went back online and the results were 37 mg/l BOD and 22 mg/l TSS. After looking into this a little, I've found out that the annual tank cleaning usually happens a month after labs, so any lab data for the system has either 5 or 11 months of continuous recirculation before sample. My thoughts are that the recirc tank water quality is still improving and those numbers should continue to drop. Throwing it out there to see if anybody has had similar experiences, concerns, or a good reference link on RSF operation to share.
