AWWA WQTC69405

This powerpoint presentation begins by providing a brief overview of the city of Hutchinson, Minnesota, and the water treatment plant (WTP) site location. Key issues included the following: exceeding copper corrosion standards as defined in the Lead & Copper Rule (LCR) in distribution system; chlorine demands were significantly different between the two treatment trains using the same water supply; high iron concentration; biological growth occurring within distribution systems; disinfection byproduct (DBP) formation; and, aging facilities. Key issues were resolved with the following results: copper corrosion standards achieved; 2007 CCR: 0.62 mg/L; uncontrollable chlorine demands; previously chlorine application varied with water production, now chlorine application H chlorine residual desired, ammonia reduced to 0.02 mg/L, and chlorine feed controllable; and, high iron concentration, Raw Water Iron concentration of 2.6 mg/L, existing plan generally controlled Iron below 0.30 mg/L, and finished water Iron = 0.01 mg/L. Includes tables, figures.