&EPA
United States
Environmental Protection
Agency
Office of Water
(4606)
EPA816-F-01-010
May 2001
vwvw.epa.gov/safewater
Stage 1 Disinfectants and Disinfection
Byproducts Rule:
A Quick Reference Guide
Overview of the Rule
Title
Purpose
General
Description
Utilities
Covered
Stage 1 Disinfectants and Disinfection Byproducts Rule (Stage 1 DBPR)
63 FR 69390 - 69476, December 16, 1998, Vol. 63, No. 241
Revisions to the Interim Enhanced Surface Water Treatment Rule (IESWTR), the Stage 1
Disinfectants and Disinfection Byproducts Rule (Stage 1 DBPR), and Revisions to State Primacy
Requirements to Implement the Safe Drinking Water Act (SDWA) Amendments
66 FR 3770, January 16, 2001, Vol 66, No. 29
Improve public health protection by reducing exposure to disinfection byproducts. Some
disinfectants and disinfection byproducts (DBPs) have been shown to cause cancer and
reproductive effects in lab animals and suggested bladder cancer and reproductive effects in
humans.
The Stage 1 DBPR is the first of a staged set of rules that will reduce the allowable levels of
DBPs in drinking water. The new rule establishes seven new standards and a treatment
technique of enhanced coagulation or enhanced softening to further reduce DBP exposure. The
rule is designed to limit capital investments and avoid major shifts in disinfection technologies
until additional information is available on the occurrence and health effects of DBPs.
The Stage 1 DBPR applies to all sizes of community water systems and nontransient
noncommunity water systems that add a disinfectant to the drinking water during any part of the
treatment process and transient noncommunity water systems that use chlorine dioxide.
Public Health Benefits
Implementation of the
Stage 1 DBPR will
result in ...
Estimated impacts of
the Stage 1 DBPR
include ..
As many as 140 million people receiving increased protection from DBPs.
24 percent average reduction nationally in trihalomethane levels.
Reduction in exposure to the major DBPs from use of ozone (DBP = bromate) and
chlorine dioxide (DBP = chlorite).
National capital costs: $2.3 billion
National total annualized costs to utilities: $684 million
95 percent of households will incur an increase of less than $1 per month.
4 percent of households will incur an increase of $1-10 per month.
<1 percent of households will incur an increase of $10-33 per month.
Critical Deadlines and Requirements
For Drinking Water Systems
January 1, 2002
January 1, 2004
Surface water systems and ground water systems under the direct
influence of surface water serving > 10,000 people must comply with the
Stage 1 DBPR requirements.
Surface water systems and ground water systems under the direct
influence of surface water serving < 10,000, and all ground water systems
must comply with the Stage 1 DBPR requirements.
For States
December 16, 2000
December 16, 2002
States submit Stage 1 DBPR primacy revision applications to EPA
(triggers interim primacy).
Primacy extension deadline - all states with an extension must submit
primacy revision applications to EPA.
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For additional information
on the Stage 1 DBPR
Call the Safe Drinking Water
Hotline at 1-800-426-4791;
visit the EPA web site at
www.epa.gov/safewater; or
contact your State drinking
water representative.
Additional material is
available at www.epa.gov/
safewater/mdbp/
implement.html.
Regulated Contaminants/Disinfectants
Regulated
Contaminants
Total Trihalomethanes (TTHM)
Chloroform
Bromodichloromethane
Dibromochloromethane
Bromoform
Five Haloacetic Acids (HAAS)
Monochloroacetic acid
Dichloroacetic acid
Trichloroacetic acid
Bromoacetic acid
Dibromoacetic acid
Bromate (plants that use ozone)
Chlorite (plants that use chlorine
dioxide)
MCL
(mg/L)
0.080
0.060
0.010
1.0
MCLG
(mg/L)
zero
0.06
zero
zero
0.3
zero
0.8
Regulated
Disinfectants
Chlorine
Chloramines
Chlorine dioxide
MRDL*
(mg/L)
4.0 as CI2
4.0 as CI2
0.8
MRDLG* I
(mg/L)
4
4
0.8
'Stage 1 DBPR includes maximum residual
disinfectant levels (MRDLs) and maximum
residual disinfectant level goals (MRDLGs)
which are similar to MCLs and MCLGs, but for
disinfectants.
Treatment Technique
Enhanced coagulation/enhanced softening to improve removal of DBF precursors (See Step 1 TOC Table) for
systems using conventional filtration treatment.
Step 1 TOC Table - Required % Removal of TOC
Source Water
TOC (mg/L)
> 2.0 to 4.0
> 4.0 to 8.0
>8.0
Source Water Alkalinity, mg/L as CaCO3
0-60
35.0%
45.0%
50.0%
> 60-120
25.0%
35.0%
40.0%
> 120
15.0%
25.0%
30.0%
1 Systems meeting at least one of the alternative compliance criteria in the rule are not required to meet the
removals in this table.
2 Systems practicing softening must meet the TOC removal requirements in the last column to the right
Routine Monitoring Requirements
TTHIWHAA5
Bromate
Chlorite
Chlorine dioxide
Chlorine/Chloramines
DBF precursors
Coverage
Surface and ground water
under the direct influence of
surface water serving > 10,000
Surface and ground water
under the direct influence of
surface water serving 500 -
9,999
Surface and ground water
under the direct influence of
surface water serving < 500
Ground water serving > 10,000
Ground water serving < 10,000
Ozone plants
Chlorine dioxide plants
Chlorine dioxide plants
All systems
Conventional filtration
Monitoring
Frequency
4/plant/quarter
1/plant/quarter
1/plant/year in month of
wannest water temperature**
1/plant/quarter
1/plant/year in month of
wannest water temperature**
Monthly
Daily at entrance to
distribution system; monthly
in distribution system
Daily at entrance to
distribution system
Same location and frequency
as TCR sampling
Monthly for total organic
carbon and alkalinity
Compliance
Running annual average
Running annual average
Running annual average
of increased monitoring
Running annual average
Running annual average
of increased monitoring
Running annual average
Daily/follow-up monitoring
Daily/follow-up monitoring
Running annual average
Running annual average
** System must increase monitoring to 1 sample per plant per quarter if an MCL is exceeded.
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