Comparisons between previously determined Coralville Reservoir conditions and water plant operations indicate that various limnological conditions are frequently accompanied by specific treatment problems at the University of Iowa Water Treatment Plant. In general, it appears that three periods of high odor values occur annually, during summer and early fall, during late winter and early spring and during early winter. It appears that the operation of the Coralville Reservoir as a flood control structure has a significant effect on limnological conditions within the impoundment and the downstream river. Preliminary comparisons indicate that extended periods of static water level or rapid drawdown may result in increased taste and odor problem at the Water Plant. Laboratory studies were undertaken using a synthesized water and running jar tests to determine what treatment process modifications would be beneficial during critical periods. From experimental runs using five different types of activated carbon, it was found that a reduction in the parameters of ammonia, tannin, and taste and odor was accomplished. Normally used activated carbon gave best removal at 70 ppm. When the water was chlorinated a taste and odor developed that made the water unsatisfactory. (Author)

"April, 1971." "Project no. A-028-IA; duration: July, 1968-June, 1970."