Microbial water quality concerns for water supply use

Abstract

AbstractThe greatest impact of water pollution on public health comes through drinking water, the source of which may be degraded by point and nonpoint pollution sources including municipal wastewater, storm water runoff, agricultural drainage, and food processing. While water treatment technology can successfully process poor quality source waters containing in excess of 2000 fecal coliforms/100 mL to produce potable water that meets the accepted drinking water standards, there is serious concern that the barriers to microbial breakthrough in the finished water may prove to be dangerously thin. Any momentary break in the treatment train could allow substantial levels of microorganisms to enter the final product—potable water.The burden of water quality enhancement should be a shared responsibility among all discharges and downstream users of these irreplaceable resources. Much can be accomplished through the application of a multiple barrier approach in wastewater treatment, controlled storm water releases, and water supply enhancement. Dischargers must seek to minimize pathogen releases, reduce particulate dispersion, and diminish organics in effluents. These factors impact heavily on the effectiveness of wastewater disinfection. Furthermore, with passage downstream to the water intake, these organic residuals may be the precursors of disinfection by‐products created during drinking water treatment. Some water supply operations must revise their treatment practices to provide better protection from the passage of protozoan cysts and enhance the removal of organics before applying disinfection. Disinfection of water supply is critical and will only be consistently effective in a clean processed water.