Hawaii Administrative Rules
Title 11 - DEPARTMENT OF HEALTH
Subtitle 1 - GENERAL DEPARTMENTAL PROVISIONS
Chapter 20 - RULES RELATING TO PUBLIC WATER SYSTEMS
Section 11-20-4.1 - Maximum contaminant levels for disinfection byproducts
Universal Citation: HI Admin Rules 11-20-4.1
Current through February, 2024
(a) Bromate and chlorite. The maximum contaminant levels (MCLs) for bromate and chlorite are as follows:
|
Disinfection byproduct |
MCL (mg/L) |
|
Bromate |
0.010 |
|
Chlorite |
1.0 |
(1)
Compliance dates for CWSs and NTNCWSs. Subpart H systems
serving 10,000 or more persons must comply with this paragraph beginning
January 1, 2002. Subpart H systems serving fewer than 10,000 persons and
systems using only ground water not under the direct influence of surface water
must comply with this paragraph beginning January 1, 2004.
(2) The Administrator, pursuant to section
1412 of the Act, hereby identifies the following as the best technology,
treatment techniques, or other means available for achieving compliance with
the maximum contaminant levels for bromate and chlorite identified in this
paragraph:
|
Disinfection byproduct |
Best available technology |
|
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 |
(b) TTHM and HAA5.
(1) Section
11-20-45.1
RAA compliance.
(A) Compliance dates. Subpart
H systems serving 10,000 or more persons must comply with this paragraph
beginning January 1, 2002. Subpart H systems serving fewer than 10,000 persons
and systems using only ground water not under the direct influence of surface
water must comply with this paragraph beginning January 1, 2004. All systems
must comply with these MCLs until the date specified in section
11-20-45.3(a)(3).
|
Disinfection byproduct |
MCL(mg/L) |
|
Total trihalomethanes(TTHM) |
0.080 |
|
Haloacetic acids(five)(HAA5) |
0.060 |
(B)
The Administrator, pursuant to section 1412 of the Act, hereby identifies the
following as the best technology, treatment techniques, or other means
available for achieving compliance with the maximum contaminant levels for TTHM
and HAA5 identified in this paragraph: Enhanced coagulation or enhanced
softening or GAC10 with chlorine as the primary and residual disinfectant.
(2) Stage 2
Disinfection Byproduct LRAA compliance.
(A)
Compliance dates. The MCLs for TTHM and HAA5 must be complied with as a
locational running annual average at each monitoring location beginning the
date specified in section
11-20-45.3(c).
|
Disinfection byproduct |
MCL(mg/L) |
|
Total trihalomethanes(TTHM) |
0.080 |
|
Haloacetic acids(five)(HAA5) |
0.060 |
(B)
The Administrator, pursuant to section 1412 of the Act, hereby identifies the
following as the best technology, treatment techniques, or other means
available for achieving compliance with the maximum contaminant levels for TTHM
and HAA5 identified in this paragraph for all systems that disinfect their
source water: Enhanced coagulation or enhanced softening, plus GAC10; or
nanofiltration with a molecular weight cutoff <=1000 Daltons; or
GAC20.
(C) The Administrator,
pursuant to section 1412 of the Act, hereby identifies the following as the
best technology, treatment techniques, or other means available for achieving
compliance with the maximum contaminant levels for TTHM and HAA5 identified in
this paragraph for consecutive systems and applies only to the disinfected
water that consecutive systems buy or otherwise receive: 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.
Disclaimer: These regulations may not be the most recent version. Hawaii may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
This site is protected by reCAPTCHA and the Google
Privacy Policy and
Terms of Service apply.
