Long Term 1 Enhanced Surface Water Treatment Rule: A Quick Reference Guide

v>EPA
United States
Environmental Protection
Agency
816F02001
on the LTIESWTR
Call the Safe Drinking Water
Hotline at 1-800-426-4791; visit
the EPA web site at
www.epa.gov/safewater/mdbp/
It1 eswtr.html; or contact your
State drinking water
representative.
1 This frequency may be reduced
by the State to once per day for
systems using slow sand/alternative
filtration or for systems serving 500
persons or fewer regardless of the
type of filtration used.
Long Term 1 Enhanced Surface
Water Treatment Rule:
A Quick Reference Guide
Overview of the Rule
Title
Purpose
General
Description
Utilities
Covered
Long Term 1 Enhanced Surface Water Treatment Rule (LT1ESWTR)
67 FR 1812, January 14, 2002, Vol. 67, No. 9
Improve public health protection through the control of microbial contaminants,
particularly Cryptosporidium. Prevent significant increases in microbial risk that
might otherwise occur when systems implement the Stage 1 Disinfectants and
Disinfection Byproducts Rule.
Builds upon the requirements of the 1989 Surface Water Treatment Rule (SWTR).
Smaller system counterpart of the Interim Enhanced Surface Water Treatment Rule
(IESWTR).
Public water systems that use surface water or ground water under the direct
influence of surface water (GWUDI) and serve fewer than 10,000 people.
Major Provisions
Control of
Cryptosporidium
Combined Filter
Effluent (CFE)
Turbidity
Performance
Standards

Filter
1
IFE
Filter Filter
2 3
IFE
'
IFE
CFE
r
The maximum contaminant level goal (MCLG) is set at zero.
Filtered systems must physically remove 99% (2-log) of Cryptosporidium.
Unfiltered systems must update their watershed control programs to
minimize the potential for contamination by Cryptosporidium oocysts.
Cryptosporidium is included as an indicator of GWUDI.
Specific CFE turbidity requirements depend on the type of filtration
used by the system.
Conventional and direct filtration:
> < 0.3 nephelometric turbidity units (NTU) in at least 95% of measurements
taken each month.
> Maximum level of turbidity: 1 NTU.

Slow sand and diatomaceous earth (DE) filtration:
> Continue to meet CFE turbidity limits specified in the SWTR:
• 1 NTU in at least 95% of measurements taken each month.
• Maximum level of turbidity: 5 NTU.
Alternative technologies (other than conventional, direct, slow sand, or DE):
> Turbidity levels are established by the State based on filter
demonstration data submitted by the system.
• State-set limits must not exceed 1 NTU (in at least 95% of
measurements) or 5 NTU (maximum).
Turbidity Monitoring Requirements
Combined Filter
Effluent
Individual Filter
Effluent (IFE)
(for systems using
conventional and
direct filtration only)
Performed at least every 4 hours to ensure compliance with CFE
turbidity performance standards.1
Since the CFE may meet regulatory requirements even though one
filter is producing high turbidity water, the IFE is measured to assist
conventional and direct filtration treatment plant operators in
understanding and assessing individual filter performance.
> Performed continuously (recorded at least every 15 minutes).
> Systems with two or fewer filters may conduct continuous monitoring
of CFE turbidity in place of individual filter effluent turbidity monitoring.
> Certain follow-up actions are required if the IFE turbidity (or CFE for
systems with two filters) exceeds 1.0 NTU in 2 consecutive readings or
more (i.e., additional reporting, filter self-assessments, and/or
comprehensive performance evaluations (CPEs)).

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 Disinfection  Profiling and Benchmarking  Requirements
 Community and non-transient non-community public water systems must evaluate impacts on microbial risk before changing disinfection
 practices to ensure adequate microbial protection is maintained. This is accomplished through a process called disinfection profiling and
 benchmarking.
 What are the disinfection profiling and benchmarking requirements?
 >  Systems must develop a disinfection profile, which is a graphical compilation of weekly inactivation of Giardia lamblia, taken on the
   same calendar day each week over 12 consecutive months. (Systems using chloramines, ozone, or chlorine dioxide for primary
   disinfection must also calculate inactivation of viruses). Results must be available for review by the State during sanitary surveys.
 >  A State may deem a profile unnecessary if the system has sample data collected after January 1,1998-during the month of warmest
   water temperature and at maximum residence time in the distribution system-indicating TTHM levels are below 0.064 mg/L and HAAS
   levels are below 0.048 mg/L.

 >  Prior to making a significant change to disinfection practices, systems required to develop a profile must calculate a disinfection
   benchmark and consult with the State. The benchmark is the calculation of the lowest monthly average of inactivation based on the
   disinfection profile.
Additional Requirements
   Construction of new uncovered finished water reservoirs is prohibited.
Critical Deadlines and Requirements
For Drinking Water Systems
March 15, 2002
July 1,2003
January 1, 2004
June 30, 2004
December 31 , 2004
January 14, 2005
Construction of uncovered finished reservoirs is prohibited.
No later than this date, systems serving between 500-9,999 persons must report to the State:
> Results of optional monitoring which show levels of TTHM < 0.064 mg/L and HAAS < 0.048 mg/L OR
> System has started profiling.
No later than this date, systems serving fewer than 500 persons must report to the State:
> Results of optional monitoring which show levels of TTHM < 0.064 mg/L and HAAS < 0.048 mg/L, OR
> System has started profiling.
Systems serving between 500 and 9,999 persons must complete their disinfection profile unless the State has
determined it is unnecessary.
Systems serving fewer than 500 persons must complete their disinfection profile unless the State has determined it is
unnecessary.
Surface water systems or GWUDI systems serving fewer than 10,000 people must comply with the applicable
LT1 ESWTR provisions (e.g., turbidity standards, individual filter monitoring, Cryptosporidium removal requirements,
updated watershed control requirements for unfiltered systems).
Far States
January 2002
October 14, 2003
January 14, 2004
December 2004
January 14, 2006
December 2006
As per the IESWTR, States begin first round of sanitary surveys (at least every 3 years for community water systems
and every 5 years for non-community water systems).
States are encouraged to submit final primacy applications to EPA.
Final primacy applications must be submitted to EPA unless granted an extension.
States must complete first round of sanitary surveys for community water systems (as per the IESWTR).
Final primacy revision applications from States with approved 2-year extension agreements must be submitted to EPA.
States must complete first round of sanitary surveys for non-community water systems (as per the IESWTR).
Public  Health  Benefits
Implementation of
the LT1 ESWTR will
result in  ...
Increased protection against gastrointestinal illnesses from Cryptosporidium and other pathogens through
improvements in filtration.
Reduced likelihood of endemic illness from Cryptosporidium by an estimated 12,000 to 41,000 cases annually.
Reduced likelihood of outbreaks of cryptosporidiosis.
Estimated impacts
of the LT1 ESWTR
include.. .
National total annualized cost: $39.5 million.
90% of affected households will incur an increase of less than $1.25 per month.
One percent of affected households are likely to incur an increase of more than $10 per month.
          Office of \^pter (4606)
                   EPA816-F-02-001
w w w. epa. gov/saf e wate r
January 2002

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