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9

3Ts: TRAINING, TESTING, TAKING ACTION
*4*
Module 4: Developing a Sampling Plan
Develop a Code System for Samples
Code each outlet using a system that will allow each unique outlet to be identified by location, type and other
relevant characteristics. The text below provides examples for coding by fixture type and sample type. The
following is an example template that can be used to designate unique samples in single-buildings.
Floor-Room Number-Outlet Type-Sample Number
The following is an example that uses the structure above and the example codes to the right. A first draw
sample (P) was taken at a drinking water fountain (DW) on the 3rd floor (003) outside of room 312 (312) and is
the 15th outlet counted (015). This sample would be coded as:
003-312-DW-P-015
If multiple buildings are being sampled, include the building number
as well.
Building Number-Floor-Room Number-Outlet Type-Sample Number
Thus, if that same drinking water fountain was located in building 1
(01), it would be coded as:
01-003-312-DW-P-015
Important Note: when taking sequential samples, be sure to add a
number to the sample to indicate the order the samples were taken in.
•	1SS= First sequential sample
•	2SS= Second sequential sample
For example, the first 125-mL sequential sample taken at that
same drinking water fountain, would be coded as:
Coding examples can include:
>
DW= drinking water fountain
>
WC = water cooler (chiller unit)
>
CF = classroom faucet
>
KF = kitchen faucet
>
BF = bathroom faucet
>
NS = nurse's office sink
>
SC = service connector
As well as the type of sample taken:
>
P = primary or first draw sample
>
F = follow-up flush sample
>
SS= sequential sample
003-312-DW-1SS-015
The coding should be identified on a site map, accompanied by a narrative that describes the observable
conditions of each sampling location. It is also important to document any special conditions for the sampling,
such as whether it was conducted after a remedy was implemented (e.g., after fixture/plumbing replacement,
after POU filter installation), during a flushing evaluation (e.g., XX hours after morning flushing), or after aerator
or inlet strainer cleaning so that results can be interpreted in the future.
Office of Water (4606M)
EPA 815-F-18-021
October 2018
v>EPA
OFFICE OF GROUND WATER
AND DRINKING WATER

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