AWWA QTC98383

This paper discusses a study to evaluate changes in biostability levels throughout a full-scale distribution system following the conversion from groundwater to biologically treated surface water. The study focused on a system which utilizes 71 wells to supply approximately 80% of the potable water used for the system. The remaining 20% is supplied by a new facility which treats river water using ozone as a predisinfectant followed by settling, biological filtration and chlorine disinfection. Nutrient levels and bacterial levels were monitored at 8 sites on a monthly basis. Total bacterial counts were determined using acridine orange staining techniques and culturable bacterial levels were measured using both R2A and SPC agars. Various water quality parameters were also evaluated including disinfectant residuals, temperature, pH, turbidity and UV254. Additional testing focused on nutrient removal during treatment and included analyses for disinfection by-products. Samples were also tested periodically for Mycobacterium avium Complex organisms. Despite significant differences in nutrient levels in groundwater and biological treated surface water, bacterial levels were similar for both sections of the distribution system. Results indicate that parameters other than nutrient levels may play a substantial role in controlling bacterial levels throughout the distribution system.

Product Details

Published:

01/01/1998

ISBN(s):

0898679796

Number of Pages:

9

File Size:

1 file , 100 KB