Section 5-1.65 - Best Available Technologies (BATs) for Disinfection Byproduct Control
Effective Date
5-1.65 Best Available Technologies (BATs) for Disinfection Byproduct Control
The following is a table of the best available technology, treatment techniques, or other means available for achieving compliance with the maximum contaminant levels for Bromate, Chlorite, TTHM and HAA5, for public water systems that disinfect their source water.
|
Water system type |
Source type |
Disinfection byproduct |
Best available technology1 |
|
All systems that disinfect their source water |
GW; SW; GWUDI |
Bromate |
Control of ozone treatment process to reduce production of bromate |
|
Chlorite |
Control of treatment processes to reduce disinfectant demand and control of disinfection treatment processes to reduce disinfectant levels |
||
|
All systems that disinfect their source water |
GW; SW; GWUDI |
Total trihalomethanes (TTHM); Haloacetic acids (five) (HAA5) |
Enhanced coagulation or enhanced softening, plus GAC10; or nanofiltration with a molecular weight cutoff ≤1000 Daltons; or GAC20 |
|
Consecutive systems: applies only to the disinfected water that consecutive systems buy or otherwise receive |
GW; SW; GWUDI |
Total trihalomethanes (TTHM); Haloacetic acids (five) (HAA5) |
Systems serving ≥10,000: Improved distribution system and storage tank management to reduce residence time, plus the use of chloramines for disinfectant residual maintenance |
|
Systems serving <10,000: Improved distribution system and storage tank management to reduce residence time |
1 Softening that results in removing at least 10 mg/L of magnesium hardness (as CaCO3), measured monthly and calculated quarterly as a running annual average can be the best available technology for controlling disinfection byproduct precursors.