AWWA QTC97104

Under the Safe Drinking Water Act (SDWA), existing and upcoming regulations require public water systems to provide a higher degree of microorganism inactivation and corrosion control while at the same time minimizing disinfection byproducts (DBPs). These goals conflict with each other. Historical water quality data collected in the Pawtucket Water Supply Board's (PWSB's) distribution system indicated that total trihalomethanes would exceed the proposed Disinfectant/Disinfection Byproduct Rule (D/DBPR) Stage II maximum contaminant limit and that raw water total organic carbon (TOC) levels may require enhanced coagulation which in turn may affect the PWSB's ability to claim CT credit for prechlorination. To ensure compliance with the upcoming D/DBPR, while maintaining compliance with existing SDWA requirements, pilot plant studies of alternative DBP control methodologies were performed at the PWSB's 27 mgd capacity conventional water treatment plant. Dissolved air flotation (DAF) was explored as an alternative high-rate clarification process to potentially replace the existing uncovered sedimentation basin. Contact filtration was piloted to determine if effluent water quality could be maintained during the potential future replacement of the sedimentation basin.

Product Details

Published:

01/01/1997

ISBN(s):

0898679583

Number of Pages:

15

File Size:

1 file , 160 KB