AWWA ACE99355

The purpose of the Stage 1 Disinfectants/Disinfection Byproducts (D/DBP) Rule is to reduce exposure to disinfection byproducts (DBPs) by enforcing maximum contaminant levels (MCL) for various DBPs and by requiring the implementation of a treatment technique to remove presursor material so that the formation of identified and unidentified DBPs are lowered. The D/DBP rule lowers the MCL for trihalomethanes and adds new MCLs for haloacetic acids, bromate, and chlorite. Enhanced coagulation, requiring certain percentage of the raw water total organic carbon removal, is defined as one of the Best Available Technologies (BAT) for the D/DBP rule. Use of granular activated carbon (GAC) adsorption is considered as another BAT. Control of disinfectant demand and the disinfection process is considered the BAT for chlorite and control of ozonation process is the BAT for bromate. Water utilities must implement enhanced coagulation or enhanced softening to achieve removal of certain percentage of total organic carbon (TOC) if the system could be categorized as follows: the source water is surface water or groundwater under the direct influence of surface water; and, the utility uses conventional treatment. Some types of treatment trains and groundwater systems are excluded from the enhanced coagulation/enhanced softening requirements because: their source waters are generally expected to be of a higher quality than water treated by conventional water treatment plants; and, the treatment trains are not typically configured to allow significant TOC removal. Further requirements are listed.

Product Details

Published:

01/01/1999

ISBN(s):

1583210016

Number of Pages:

16

File Size:

1 file , 190 KB