DDW-2025-001752

195 North 1950 West • Salt Lake City, UT
Mailing Address: P.O. Box 144830 • Salt Lake City, UT 84114-4830
Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.utah.gov
Printed on 100% recycled paper
State of Utah

SPENCER J. COX
Governor

DEIDRE HENDERSON
Lieutenant Governor
Department of
Environmental Quality

Kimberly D. Shelley
Executive Director

DIVISION OF DRINKING WATER
Nathan Lunstad, Ph.D., P.E.
Director

February 4, 2025

Clyde Watkins
Duchesne County WCD
PO Box 133
Altamont, UT 84001

Subject: Increased Disinfection Byproduct Monitoring for Duchesne County WCD
UTAH07069

Dear Clyde Watkins:

The Utah Division of Drinking Water has changed the disinfection byproduct (DBP) sampling
requirements for Duchesne County WCD because the system's annual averages for Total Trhialomethanes
(TTHMs) and Total Haloacetic Acids (HAA5) in 2024 exceeded 60 ug/L and 45 ug/L, respectively [R309-
210-10(6)]. The system may return to its previous reduced monitoring schedule if the annual averages are
less than 40 ug/L for TTHMs and less than 30 ug/L for HAA5 after four quarters of monitoring.

DBP Monitoring Requirements
The water system is now required to collect four (4) DBP sample(s) per quarter. Each sample must be a
dual sample set of total trihalomethanes (TTHMs) and haloacetic acids (HAA5). The next DBP samples
must be collected during the April 1 - June 30, 2025, monitoring period.

Sample Site Plan Update
The system must submit an updated DBP sample site plan to the Division within 30 days of this
letter. A sample site plan template with instructions has been enclosed. The plan must include
at least four (4) site(s).

Questions
You may access an updated version of your water system’s monitoring schedule at waterlink.utah.gov by
searching for your water system and then clicking “Water Monitoring.” If you have any questions, please
contact Luke Treutel at [phone] or [e-mail].

Page 2

Sincerely,
Mark Berger
Monitoring & Standards Section Manager

Enclosure: DBP Sample Site Plan Template

cc: Clyde Watkins, Duchesne County WCD, [e-mail]
Joe Hadlock, TriCounty Health Department, [e-mail]
Luke Treutel, Division or Drinking Water, [e-mail]
Nathan Hall, DEQ District Engineer, [e-mail]
Revised 7/30/2021
Utah Division of Drinking Water
Stage 2 Disinfectant Byproduct (DBP) Sampling Plan
In accordance with State of Utah Rule R309-210-10(3): Any Community (COM) or Non-Transient Non-Community
(NTNC) drinking water system that regularly applies a chemical disinfectant must develop and implement a DBP
monitoring plan. The system must maintain current version of the plan on file and submit a copy of 1) the monitoring
plan, 2) a schematic of the distribution system, and 3) the justification for site selection (IDSE water, modeling analysis,
etc.) to the Division of Drinking Water.
BASIC WATER SYSTEM INFO
Water System Name: Water System #:
Residual Disinfectant Type: ☐ Chlorine ☐ Chlorine Dioxide ☐ Ozone
# of Service Connections:
Population (# of customers):
Sampling Schedule ( # of sampling locations):
Per Quarter Per Year
SITE SELECTION INFO
Associated Rules:
R309-210-9(2)(b)(i)(Q): A dual sample set (i.e., a TTHM and an HAA5 sample) must be
taken at each monitoring location during each monitoring period.
Associated Info:
Disinfection By Product Sampling
schedules are based on
population and source water
type. DBPs may be required
quarterly, annually, or every
three years. For a complete list of
possible schedules please see
associated DBP handout.
•One dual sample set must be taken at the
highest TTHM (trihalomethanes) sampling
site, at a location that represents
maximum residence time; typically in the
furthest reaches of your distribution
system, or where water is oldest.
This location is denoted as MR001.
•One dual sample set must be taken
at the highest HAA5 (haloacetic
acids) sampling site, at a location
that represents the average
residence time; typically located mid
distribution system
This location is denoted as MD001.
R309-210-10(3)(ii):
•Water system must identify which locations will be used for compliance monitoring
by alternating selection of locations representing high TTHM and high HAA5 levels
until the required number of compliance monitoring locations have been identified.
Water system sampling
schedules with sampling
locations and details are available
at any time at
WaterLink.utah.gov
SAMPLES
Sample
Code
Specific sampling location
ADDRESS
Site Characteristics / Site Selection Justification
(check those that apply)
MR001
MR002
MR003
MR004
☐Highest TTHM/HAA5 in prior data☐Endpoint of distribution system and/or maximum water age☐Other:
MD001 MD002 MD003 MD004
☐Highest TTHM/HAA5 in prior data☐Midpoint of a large distribution system☐Endpoint of distribution system and/or maximum water age☐Other:
Annual samples must be collected within a specific time frame in accordance with State of Utah Rules
R309-210-10(2)(a)(ii)(N): All systems must monitor during months of highest DBP concentrations.
R309-210-9(2)(b)(i)(R): The peak historical month is the month with the highest TTHM or HAA5 levels or the
warmest water temperature.
Source Water Types:
☐Ground water
☐Ground water purchasing from wholesale Water System #: UTAH
☐Ground water Under Direct Influence of surface water
☐Surface water
☐Surface water purchasing from wholesale Water System #: UTAH
CERTIFICATION
I certify that I am the person authorized to fill out this application and the information I have provided is
accurate and complete to the best of my knowledge at the time it was completed.
X X
Printed Name Signature
Date: Title: ☐ Administrative Contact ☐ Operator
SUBMITTAL
Mail the completed form to:
Or Email:
Division of Drinking Water
Attn: DBP Rule Manager
195 N 1950 W
PO BOX 144830
Salt lake City, UT 84114
[e-mail]
This application and related environmental information are available online at DrinkingWater.utah.gov
For more information, or to answer questions, please contact the DBP Rule Manager, Luke Treutel at [phone]
[e-mail]
Revised 7/30/2021