AWWA ACE63070

This slide presentation outlines a plant optimization project to meet the Disinfectant/Disinfection Byproduct (D/DBP) Rule. Issues outlined include: Disinfection Byproducts; TOC Removal; Cold water turbidity removal; and, Disinfection Profiling. A two track approach was used: remove as much turbidity and organic matter as possible; and, refine disinfection for best CT. The project involved the Broad Brook Plant in Meriden, Connecticut, with characteristics that include: Largest Individual Source ¿¿¿¿¿¿¿¿ 4.3 mgd; conventional plant processes upgraded in 1976; most complex chemical treatment options; and, seasonal manganese episodes. Plant findings include: alum coagulated total organic carbon (TOC) but floc didn't settle in cold water (verified in jar tests); if UV@254 removal >50%, TOC removal >35%; powdered activated carbon worked best when added at rapid mix (jar tested first, then full scale) and resulted in better TOC removal, less chlorine demand, and small un-baffled clearwell. Jar test findings are outlined and results of the Meriden Plant optimization included: better coagulant for cold water was found; separated powdered activated carbon (PAC) from pre-chlorine, resulting in better organic removal, lower chlorine demand; UV@254, tool to measure TOC removal; and, spreadsheets for disinfection profiling. Includes figures.