AWWA JAW24301

Cast-iron test surfaces in a distribution system were exposed to ascertain the relationship between suspended microbial population density, chloramine residual, velocity, water temperature, and selected average solute concentrations and attached microbial population density. The population of attached microorganisms was directly related to water temperature and suspended microbial population density and indirectly related to chloramine concentrations and maximum velocity using either analysis of variance or linear correlation. Statistical analysis using linear correlation could demonstrate no strong relationships between pH, alkalinity, organic nitrogen, ammonia, nitrite, nitrate, total phosphate, orthophosphate, or total organic carbon and attached microbial population density. Includes 17 references, tables, figures.