Checklist:
Disinfection Profiling for the
LT1 ESWTR
/I? 1 989, EPA published the Surface Water Treatment Rule to control microbial
pathogens in drinking water. On January 14, 2002, EPA finalized the Long Term 1
Enhanced Surface Water Treatment Rule (LT1 ESWTR) to improve control of
microbial pathogens. Among other provisions, it requires certain public water
systems to evaluate their disinfection practices (through a process called
disinfection profiling). The purpose of disinfection profiling is to help ensure
there is not a reduction in microbial protection if changes are made to
disinfection practices to comply with new maximum contaminant levels
established by the December 1998 Stage 1 Disinfectants and Disinfection
Byproducts Rule (Stage 1 DBPR).
This checklist will step you through the disinfection profiling requirements to help you
determine what activities you must conduct and when the activity must be completed.
PART 1 : System Type
Please answer the following questions to see if your system is subject to the
. ...... YES NO
1 .) Does your system use surface water or ground water I — | i — ^
under the direct influence of surface water (GWUDI)? <-J *— J
2.) Is your system a community or non-transient non-community water system? Q Q
3.) Does your system serve fewer than 10,000 people? Q Q
"^ If you answered NO to one or more questions, this fact sheet does not apply to you.
«& If you answered YES to all three questions in Part 1 , please go to Part 2. You are
subject to the disinfection profiling and benchmarking requirements unless your State
determines that you have acceptable data on disinfection byproducts.
PART 2: Disinfection Byproduct (DBP) Sampling
Systems that can demonstrate low DBP levels are less likely to make a change in disinfection practices
to meet the Stage 1 DBPR requirements, and therefore may not have to create a disinfection profile.
Please answer the following questions to see if your data qualifies. YES NO
4.) Have you collected a sample for total trihalomethanes (TTHM) and five ,-, ,-,
haloacetic acids (HAAS) after January 1 , 1 998 ? LJ LI
^ If you answered NO to question 4, go to Part 3.
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PART 2: Disinfection Byproduct Sampling (Continued) YES NO
5.) Let's look at your TTHM data
a.) Was the TTHM sample collected during the month of warmest water '—• *—'
temperature?
b.) Was the TTHM sample collected at a point where the water has Q Q
remained in the distribution system for the longest time (i.e. maximum
residence time)?
c.) Was the TTHM sample result less than 0.064 mg/L? Qj Q
6.) Let's look at your HAAS data:
a.) Was the HAAS sample collected during the month of warmest water Qj Q
temperature?
b.) Was the HAAS sample collected at a point where the water has r—v r—j
remained in the distribution system for the longest time (i.e. maximum "—I "—I
residence time)?
c.) Was the HAAS sample result less than 0.048 mg/L? Q Q
w If you answered NO to one or more questions in Part 2, go to Part 3.
E5- If you answered YES to all the questions in Part 2, your State may determine you do not
have to develop a disinfection profile. Please contact your State agency.
PART 3: Your Options.
If you have gotten to Part 3, you are subject to the disinfection profiling requirement because you do not
have TTHM and HAAS data or the data you have does not meet all the requirements outlined in Part 2.
Please read the following options and decide what option is best for your system.
Q OPTION 1 - Plan to collect TTHM and HAAS samples this summer (i.e. month of warmest water
temperature). Collect one TTHM sample and one HAAS sample in your distribution system where
the water remains the longest (maximum residence time) during the month of warmest water
temperature.
KP If your TTHM sample result is less than 0.064 mg/L and your HAAS sample result is less
than 0.048 mg/L, your State may determine you do not have to develop a disinfection
profile. Please contact your State agency.
us? If you are at or above these levels go to Part 4.
Q OPTION 2 - Go straight into disinfection profiling. Disinfection profiling consists of determining your
system's level of inactivation once a week for one year. See Part .4 for more detail.
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Part 4: Disinfection Profile - What you need to know
WHAT is A DISINFECTION PROFILE?
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A disinfection profile provides a description of your
system's disinfection practices. It is a graphical
representation of your system's level of inactivation for
Giardia lamblia each week for a period of one year. If
your system uses chloramines, ozone or chlorine dioxide
for primary disinfection, you must also calculate in-
activation of viruses. The disinfection profile does not
need to be submitted to the State. However, it must be available for review during a sanitary survey.
1.400 ,
1200-j
| 1,000 -
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j 0.600
J 0.400
"* 0200 ',
0.000 -i r
0 4
12 16 20 24
32 36 40 44 48 52
Week Tested
How is A DISINFECTION PROFILE DEVELOPED? WHAT DATA NEEDS TO BE COLLECTED?
Inactivation values for the disinfection profile are calculated from operational data collected on the
same day each week, over the course of one year.
The following data used for inactivation calculations must be collected during peak hourly flow:
> Data Collected at each sampling location
>• Disinfectant residual concentration ("C", in mg/L),
>• Contact time ("T", in minutes),
>• Water temperature (in degrees Celsius) and
>• pH (only for systems using chlorine).
> Sampling locations
> Before or at the first customer
*• Prior to each additional point of disinfection
"^ An electronic spreadsheet that calculates inactivation values is posted on the EPA website at
http://www.epa.gov/safewater/mdbo/lt1eswtr.html.
«& More detailed information on how to create a disinfection profile is available in EPA 's LT1ESWTR
Profiling and Benchmarking Guidance Manual which is posted on the EPA website at
http://www.epa.gov/safewater/mdbp/lt1eswtr.html.
WHEN DO I BEGIN COLLECTING DATA FOR MY DISINFECTION PROFILE?
If your system serves...
500 to 9,999 people
fewer than 500 people
Begin your disinfection profile by...
July 1,2003
January 1 , 2004
A CHANGE TO YOUR DISINFECTION PRACTICES?
If you are thinking about making a change to your disinfection practices, you must
consult with your State prior to making any changes.
Please contact the Safe Drinking Water Hotline at 1-800-426-4791 or
visit http://www.epa.gov/safewater/mdbp/lt1eswtr.html for more information.
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Your water system is expected to be affected
by the requirements of the new Long Term 1
Enhanced Surface Water Treatment Rule.
However EPA wants to let you know how you may be able to
reduce your workload by planning ahead I
PLEASE LOOK INSIDE
Office of Water (4606M) EPA816-F-02-009 www.epa.gov/safewater April 2002
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