EPA
    United States
    Environmental Protection
    Agency
       *:



Comprehensive Surface Water Treatment Rules
Quick Reference Guide: Systems Using Conven
tional or Direct Filtration
                         Overview  of the Rules
                         Title
                         Purpose
                         General
                         Description
           Surface Water Treatment Rule (SWTR) - 40 CFR 141.70-141.75
           Interim Enhanced Surface Water Treatment Rule (IESWTR) - 40 CFR 141.170-141.175
           Filter Backwash Recycling Rule (FBRR) - 40 CFR 141.76
           Long Term 1 Enhanced Surface Water Treatment Rule (LT1ESWTR) - 40 CFR
           141.500-141.571
           Improve public health protection through the control of microbial contaminants, particularly
           viruses, Giardia, and Cryptosporidium.
           The Surface Water Treatment Rules:
           > Applies to all public water systems (PWSs) using surface water or ground water under
             the direct influence of surface water (GWUDI), otherwise known as "Subpart H
             systems."
           >  Requires ail Subpart H systems to disinfect.
           >  Requires Subpart H systems to filter unless specific filter avoidance criteria are met.
           >  Requires individual filter monitoring and establishes combined filter effluent (CFE) limits.
           > Applies a treatment technique  requirement for control of microbials.
Overview of Requirements
The purpose of this table is show how the requirements for the IESWTR and LT1 ESWTR build on
the existing requirements established in the original SWTR.
APPLICABILITY: PWSs that use surface water or
ground water under the direct influence of
surface water (Subpart H) that practice
conventional or direct filtration.
Population Served
Regulated
Pathogens
Residual
Disinfectant
Requirements
Turbidity
Performance
Standards
Disinfection Profiling
& Benchmarking
Sanitary Surveys
(state requirement)
>1 0,000
< 10,000
99.99% (4-log)
removal/inactivation of viruses
99.9% (3-log)
removal/inactivation of Giardia
lamblia
Final Rule Dates
SWTR
1989
V
/
V
/
99% (2-log) removal of
Cryptosporidium
Entrance to distribution system
(>0.2 mg/L)
Detectable in the distribution
system
Combined Filter Effluent
Individual Filter Effluent
V
/
V
m
IESWTR
1998
V
N/A (except
for sanitary
survey
provisions)
Regulated
under SWTR
Regulated
under SWTR
'
Regulated
under SWTR
Regulated
under SWTR
/
V
Systems must profile
inactivation levels and generate 1 ^
benchmark, if required H H
CWS: Every 3 years
NCWS: Every 5 years
Covered Finished Reservoirs/Water Storage Facilities
(new construction only)
Operated by Qualified Personnel as Specified by
State
-
/
/
V
Regulated
under SWTR
LT1 ESWTR
2002
	
/
Regulated
under SWTR
Regulated
under SWTR
V
Regulated
under SWTR
Regulated
under SWTR
FBRR
2001
V
/
Regulated
under SWTR
Regulated
under SWTR
Regulated
under
IESWTR &
LT1 ESWTR


I
'
/
Regulated
under
IESWTR
V
Regulated
under SWTR



Regulated
under SWTR
                        (CWS) Community Water System    (NCWS) Non-community Water System

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Turbidity
There are two ways turbidity is measured: Combined Filter Effluent (CFE) and Individual Filter Effluent (IFE).
Turbidity Reporting Requirements
(Reports due by the 10th day of the following
month the system serves water to the
public.)
CFE 95% Value
Report total number of CFE measurements
and number and percentage of CFE
measurements < 95th % limit.
CFE Maximum Value
Report date and value of any CFE
measurement that exceeded CFE maximum
limit.
IFE Monitoring
Report IFE monitoring conducted and any
follow-up actions.
Monitoring/
Recording
Frequency
At least every
4 hours*
At least every
4 hours*
Monitor
continuously
every 15
minutes
SWTR
As of June
29, 1993
< 0.5 NTU
5 NTU
Contact state
within 24
hours
None
IESWTR
> 10,000 people
As of January 1, 2002
< 0.3 NTU
1 NTU
Contact state within 24
hours
Monitor-exceedances
require follow-up action
LT1ESWTR
< 10,000 people
As of January 1,2005
< 0.3 NTU
1 NTU
Contact state within 24
hours
Monitor-exceedances
require follow-up action.
Systems with 2 or fewer
filters may monitor CFE
continuously in lieu of IFE.
*Monitoring frequency may be reduced by the state to once per day for systems serving 500 or fewer people.
IFE Follow-Up and Reporting Requirements
Condition
2 consecutive
recordings >0.5 NTU
taken 15 minutes
apart at the end of the
first 4 hours of
continuous filter
operation after

backwash/offline:


2 consecutive
recordings > 1.0 NTU
taken 15 minutes
apart:


2 consecutive
recordings > 1 .0 NTU
taken 15 minutes
apart at the same
filter for 3 months in




2 consecutive
recordings > 2.0 NTU
taken 15 minutes
apart at the same
filter for 2 months in a


IESWTR (> 10,000)
Action


Produce filter
profile within 7
days (if cause
not known)





Produce filter
profile within 7
days (if cause
not known)


Conduct filter
self-assessment
within 14 days




Arrange for CPE
within 30 days &
submit report
within 90 days


Report
>. Filter*
> Turbidity value
>. Date
> Cause
(if known) or
report profile



>. Filter*
> Turbidity value
>. Date
> Cause
(if known) or
report profile
was produced
>. Filter #
>. Turbidity value
>. Date
>. Report filter
self-
assessment

produced

>. Filter #
>. Turbidity value
>. Date
Submit CPE
report

By

LT1ESWTR(< 10,000)**
Action


1 0th of the I
following
month








10th of the
month



1 0th of the
following
month




1 0th of the
following
month
90 days
after

exceedance
Conduct a filter
self -assessment
within 14 days.
Systems with 2
filters that
monitor CFE in


do both filters.

Arrange for CPE
within 60 days &
report within 120
days

Report










>. Filter #
>. Turbidity value
>. Date
>. Cause
(if known)

>. Date filter self-
assessment
triggered &
completed




>. Date CPE
triggered
Submit CPE
report

By











1 0th of the
following month


1 0th of the
following month
(or within 14
days of filter
self -assessment
being triggered
if triggered in

last 4 days of
the month)
1 0th of the
following month
120 days after
exceedance

** Systems serving fewer than 10,000 people must begin complying with these requirements beginning January 1, 2005.

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IFE performance is measured in systems using conventional or direct filtration. The performance of each individual filter is
critical to controlling pathogen breakthrough.  The CFE turbidity results may mask the performance of an individual filter
since the individual filter may have a turbidity spike of a short duration not detected by 4 hour CFE readings.

The IESWTR and LT1ESWTR created more stringent CFE turbidity standards and established a new IFE turbidity monitoring
requirement to address Cryptosporidium. These new turbidity standards assure conventional and direct filtration systems will
be able to provide 2-log Cryptosporidium removal.

Disinfection

Disinfection must be sufficient to ensure that the total treatment process (disinfection plus filtration) of the system achieves
at least:

>       99.9% (3-log) inactivation and/or removal of Giardia lamblia.
>       99.99% (4-log) inactivation and/or removal of viruses.


Cryptosporidium must be removed by filtration and no inactivation credits are currently given for disinfection.  Systems
must also comply with the maximum residual disinfectant level (MRDL) requirements specified in the Stage 1 Disinfectants/
Disinfection Byproducts Rule (Stage 1 DBPR).
 Residual  Disinfectant  Monitoring and  Reporting  Requirements
       Location
        Concentration
   Monitoring Frequency
            Reporting
  (Reports due 10th of the following
             month)
 Entry to distribution
 system.
Residual disinfectant concentration
cannot be < 0.2 mg/L for more
than 4 hours.
Continuous, but states may
allow systems serving 3,300
or fewer persons to take grab
samples from 1 to 4 times per
day, depending on system
size.
Lowest daily value for each day, the
date and duration when residual
disinfectant was < 0.2 mg/L, and when
state was notified of events where
residual disinfectant was < 0.2 mg/L.
 Distribution system -
 same location as total
 coliform sample
 location(s).
Residual disinfectant concentration
cannot be undetectable in greater
than 5% of samples in a month, for
any 2 consecutive months.
Heterotrophic plate count (HPC) <
500/mL is deemed to have
detectable residual disinfectant.
Same time as total coliform
samples.
Number of residual disinfectant or HPC
measurements taken in the month
resulting in no more than 5% of the
measurements as being undetectable in
any 2 consecutive months.

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Disinfection Profiling and  Benchmarking Requirements

A disinfection profile is the graphical representation of a system's microbial inactivation over 12 consecutive months.

A disinfection benchmark is the lowest monthly average microbial inactivation value. The disinfection benchmark is used
as a baseline of inactivation when considering changes in the disinfection process.
 Disinfection  Profiling and  Benchmarking  Requirements  Under
 IESWTR &  LT1ESWTR
 The purpose of disinfection profiling and benchmarking is to allow systems and states to assess whether a change in disinfection
 practices creates a microbial risk. Systems should develop a disinfection profile that reflects Giardia lamblia inactivation (systems using
 ozone or chloramines must also calculate inactivation of viruses), calculate a benchmark (lowest monthly inactivation) based on the
 profile, and consult with the state prior to making a significant change to disinfection practices.
      REQUIREMENT
                   IESWTR
                    LT1ESWTR
 AFFECTED SYSTEMS:
                         Community, non-transient non-community, and
                                             Community and non-transient non-community
                                             systems only.
 BEGIN PROFILING BY:
 April 1,2000
    > July 1, 2003 for systems serving 500-9,999
      people.
    > January 1, 2004 for systems serving fewer than
      500 people.
 FREQUENCY &
 DURATION:
 Daily monitoring for 12 consecutive calendar
 months to determine the total logs of Giardia
 lamblia inactivation (and viruses, if necessary) for
 each day in operation.
    Weekly inactivation of Giardia lamblia (and viruses,
    if necessary), on the same calendar day each week
    over 12 consecutive months.
 STATES MAY WAIVE
 DISINFECTION
 PROFILING
 REQUIREMENTS IF:
 TTHM annual average <0.064 mg/L and HAA5
 annual average <0.048 mg/L:
 >  Collected during the same period.
 >  Annual average is arithmetic average of the
    quarterly averages of four consecutive quarters
    of monitoring.
 >  At least 25% of samples at the maximum
    residence time in the distribution system.
 >  Remaining 75% of samples at representative
    locations in the distribution system.
    One TTHM sample <0.064 mg/L and one HAA5
    sample <0.048 mg/L:
    >  Collected during the month of warmest water
       temperature; AND
    >  At the maximum residence time in the
       distribution system.

    Samples must have been collected after January 1,
    1998.
 DISINFECTION
 BENCHMARK MUST BE
 CALCULATED IF:
 Systems required to develop a disinfection profile
 and are considering any of the following:
 >  Changes to the point of disinfection.
 >  Changes to the disinfectant(s) used.
 >  Changes to the disinfection process.
 >  Any other modification identified by the state.

 Systems must consult the state prior to making any
 modifications to disinfection practices.
                                                                    Same as IESWTR, and systems must obtain state
                                                                    approval prior to making any modifications to
                                                                    disinfection practices.
Filter Backwash  Recycling Rule

The FBRR applies to PWSs that use surface water or ground water under the direct influence of surface water, practice
conventional or direct filtration, and recycle spent filter backwash, thickener supernatant, or liquids from dewatering pro-
cesses. The FBRR requires systems that recycle to return specific recycle flows through all processes of the system's
existing conventional or direct filtration system or at an alternate location approved by the state. The FBRR was developed
to improve public health protection by assessing and changing, where needed, recycle practices for improved contaminant
control, particularly microbial contaminants. Systems were required to submit recycle notification to the state by December
8,2003.
 Filter  Backwash  Critical Deadlines  and  Requirements
 June 8, 2004
   Return recycle flows through the processes of a system's existing conventional or direct filtration system
   or an alternate recycle location approved by the state (a 2-year extension is available for systems
   making capital improvements to modify the recycle return location).
   Collect recycle flow information and retain on file.
 June 8, 2006
Complete all capital improvements associated with relocating recycle return location (if necessary).
     Office of Water (4606)
           EPA816-F-04-003
www.epa.gov/safewater
August 2004

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