Section 611.312 Maximum Contaminant Levels (MCLs) for Disinfection Byproducts (DBPs)

Section 611

TITLE 35: ENVIRONMENTAL PROTECTION

SUBTITLE F: PUBLIC WATER SUPPLIES

CHAPTER I: POLLUTION CONTROL BOARD

PART 611 PRIMARY DRINKING WATER STANDARDS

SECTION 611.312 MAXIMUM CONTAMINANT LEVELS (MCLS) FOR DISINFECTION BYPRODUCTS (DBPS)

Section 611.312  Maximum

Contaminant Levels (MCLs) for Disinfection Byproducts (DBPs)

a)         Bromate and Chlorite.  MCLs for bromate and chlorite

apply to CWS and NTNCWS suppliers

:

Disinfection

Byproduct

MCL

(mg/L)

Bromate

0.010

Chlorite

1.0

1)         A Subpart

B system supplier must comply with this subsection (a).

2)         USEPA

identifies best available technology, treatment techniques, or other means

available for achieving compliance with the MCLs for bromate and chlorite:

Disinfection

Byproduct

Best Available

Technology

Bromate

Controlling the ozone

treatment process to reduce bromate production.

Chlorite

Controlling the treatment

processes to reduce disinfectant demand and controlling the disinfection

treatment processes to reduce disinfectant levels.

b)         TTHM and HAA5

1)         A

supplier must comply with the Subpart Y MCLs for TTHM and HAA5 as a locational

running annual average at each monitoring location, as Section 611.970(c)

requires.

Disinfection

B

yproduct

MCL (mg/

L

)

Total trihalomethanes (TTHM)

0.080

Haloacetic acids (five) (HAA5)

0.060

2)         USEPA

identifies the best available technology, treatment techniques, or other means

available for complying with the MCLs for TTHM and HAA5 for any supplier disinfecting

its source water:

Disinfection

B

yproduct

Best Available

Technology

Total trihalomethanes (TTHM) and

Haloacetic acids (five) (HAA5)

Enhanced coagulation or

enhanced softening, plus GAC10; or nanofiltration with a molecular weight

cutoff ≤ 1000 Daltons; or GAC20

3)         USEPA

identifies the best available technology, treatment techniques, or other means

available for achieving compliance with the MCLs TTHM and HAA5 for consecutive

systems, which only apply to the disinfected water that a consecutive system

(five) (HAA5)

Enhanced coagulation or

enhanced softening, plus GAC10; or nanofiltration with a molecular weight

cutoff ≤ 1000 Daltons; or GAC20

3)         USEPA

identifies the best available technology, treatment techniques, or other means

available for achieving compliance with the MCLs TTHM and HAA5 for consecutive

systems, which only apply to the disinfected water that a consecutive system

buys or otherwise receives from a wholesale system:

Disinfection

B

yproduct

Best Available Technology

Total trihalomethanes (TTHM) and

Haloacetic acids (five) (HAA5)

Any system serving 10,000 or

more persons:  Improved distribution system and storage tank management to

reduce residence time, plus using chloramines for disinfectant residual maintenance;

or Any system serving fewer than 10,000 persons:  Improved distribution

system and storage tank management to reduce residence time.

BOARD NOTE:

This Section derives

from 40 CFR 141.64.