AWWA WQTC65951

This powerpoint presentation provides a brief overview of the Cleveland Water Division (CWD), and the problem it was having with: low Cl₂ residuals in a portion of the transmission mains; suspected biofilm issues; distribution system model not suitable for this arrangement, water age unknown for this small area; and, low flow demands. The approach used included: fluoride tracer study; shut off F- feed at Crown and Morgan Water Treatment Plants (WTPs), maintain at Baldwin WTP; sample strategically; control the variables; draw conclusions from data; and, pipe section sampling considered, but shelved due to cost. Conclusions were that: Independence Pump Station will not put water into Brecksville system if the bleeds are open; with bleeders open, 3rd high pushes water back towards Independence; water from Independence then flows towards Parma; Chlorine Residuals will not increase in Brecksville system as long as bleeders are open as they were in the study; chlorine residual in 3rd high service near Brecksville is low; a biofilm is quite likely since there has been low chlorine in system for some time; open or closed, bleeders will cause water quality issues; and, CWD will expend capital dollars to address. Includes figures.