Ammonia is oxidized to nitrate also during the aeration process. The underflow from these tanks provides a source of material to re-seed the aeration stage. Clean water overflows the weirs of these tanks. We have 3 secondary tanks. Two 100' diameter tanks and one 142' diameter tank.
Disinfection is by the addition of sodium hypochlorite solution.
Here there is a pump gallery in the basement for transferring between treatment units. The sludge is stabilized by adding quick lime in a pug mill mixer. The new LASA laboratory was completed in November of 1998. There are three full-time laboratory technicians on staff to perform analyses and record results used for wastewater processing control and to verify N.P.D.E.S permit compliance. In addition, wastewater samples collected at industrial facilities are sometime tested at this laboratory as part of the US EPA approved pretreatment program administration.