DDW-2025-004987

May 22nd, 2025
Lehi City
2538 N 300 W
Lehi, Utah 84043
Dear David Norman:
Subject: Closeout of Source Assessment Monitoring Requirements –
Lehi City (UTAH25015), Sampling Station - 05 06 08 (SS994)
The Division of Drinking Water records indicate that you are the responsible party for the Lehi
City public water system. The Lehi City water system is a public water system and thus subject
to the Administrative Rules for Public Drinking Water Systems.
Starting in April 2021, Lehi City began source assessment sampling at Sampling Station - 05
06 08 (SS994) as part of a conditional plan approval letter. Source Assessment sampling has
been completed. Results of sampling are below.
Number of Samples Sample Results
40 samples taken at Sampling Station - 05 06 08
(SS994)
All samples were Total Coliform absent
Elective Disinfection Requirements
Based on the sample results, the water system is not required to disinfect the School House Spring
(WS005), the Hamongog Spring (WS006), or the Birch Spring (WS008), which combine at the
sampling station. The Division’s records indicate that the School House Spring (WS005) is treated
by the School House Spring Chlorinator (TP005). Because the source sample results were
satisfactory, the chlorinator is considered to provide disinfection on an elective (i.e. voluntary)
basis. Because of this, the water system must comply with the elective disinfection requirements
described in Addendum A. These requirements should look familiar, but they are included here as
a reminder.
David Norman
Page 2
Lehi City Water System must provide continuous disinfection to maintain detectable chlorine
residuals throughout the distribution system. The water system must not discontinue
chlorination without approval from the Division of Drinking Water and must notify the
Division by telephone at [phone] within eight hours of the malfunction of any
disinfection facility such that a detectable residual cannot be maintained at all points in the
distribution system per R309-105-18(1)(a).
Please be aware if Lehi City Water System is found to require additional disinfection in the future
per R309-200-5(7)(a)(i), further regulations will apply. For example, if primary disinfection is
required this will include submitting disinfection CT information showing compliance with 4-log
virus inactivation in accordance with the Ground Water Rule in R309-215-16. If you require
assistance in responding to this notice, please contact Luke Treutel at [phone] or
ltreutel @utah.gov .
Sincerely,
Mark Berger
Rules Section Manager
Enclosure: Addendum A - Elective Disinfection Monitoring and Reporting Requirements
Chlorinator Operational Report Template
cc: David Norman, [e-mail]
Daymon Swenson, Utah County Health Department
Mark Berger, Division of Drinking Water, [e-mail]
VSA Team, Division of Drinking Water, [e-mail]
Michael Newberry, Division of Drinking Water, [e-mail]
Jennifer Yee, Division of Drinking Water, [e-mail]
Addendum A - Elective Disinfection Monitoring and Reporting Requirements
To meet elective disinfection requirements, Lehi City will be required to demonstrate a
detectable chlorine residual throughout the distribution system and complete chlorinator
operational reports.
Chlorinator Operational Reports
The water system must complete a monthly operational report for each chlorinator. Information
about submitting operational reports is included in the “Disinfection Report Submission” section
of this addendum. The following information must be provided in the reports:
1. The water system must measure and record the chlorine level at the point of entry (POE)
to the distribution system a minimum of three (3) times per week. [R309-215-10(1)]
a. The POE sampling location is identified as EP005 in the Division’s database.
■ The specific POE location must be provided to the Division within 30
days from the date of this letter.
b. Maintain a minimum of 0.2 mg/L residual (measured as free chlorine) at the POE
sampling location. [R309-215-16(3)(b)(iii)(A)(I) and (II)]
c. The chlorine residual concentration measured at the POE sampling location shall
not exceed the maximum residual disinfectant level (MRDL) of 4.0 mg/L
(measured as free chlorine). [R309-200-5(3)(c)(iv)]
2. In addition to the POE residual monitoring, The water system must take the following
readings at each chlorinator a minimum of three times a week [R309-210-8(3)(a)]:
a. The total volume of water treated
b. The type and amount of disinfectant used in treating the water, clearly indicating
the weight if gas feeders are used, or the percent solution and volume fed if liquid
feeders are used
c. The setting of the rotometer valve or injector pump
Chlorine Residual ‒ Distribution System (DS001)
1. This water system must maintain a detectable residual throughout the distribution
system . It is recommended to maintain the chlorine residual above 0.1 ppm in the
distribution system. [R309-520-5]
2. The chlorine residual measured in the distribution system shall not exceed the maximum
residual disinfectant level (MRDL) of 4.0 mg/L (measured as free chlorine).
[R309-200-5(3)(c)(iv)]
3. Take a minimum of three (3) chlorine residual samples per week at varying locations
throughout its distribution system ( DS001 ). [R309-105-10(1)(c)]
4. Distribution system chlorine residuals must be taken in conjunction with total coliform
sampling. [R309-215-10(3)]
5. The water system must submit a summary of the chlorine residual data to the Division.
Information about submitting the chlorine residual data is included in the “Disinfection
Report Submission” section of this addendum.
Disinfection Report Submission
To demonstrate ongoing compliance with elective disinfection requirements, the Lehi City water
system must complete monthly operational reports for each active chlorinator using a template
approved by the Division.
1. Operational reports are submitted quarterly . The operational report template has been
enclosed with this letter. The reports are due to the Division by the 10th day following the
end of each reporting month or quarter (i.e., January 10th, April 10th, July 10th and
October 10 th for quarterly reports). The reports should be submitted through the Division’s
online form found on the mrdl.utah.gov webpage, along with the chlorine residual
summaries.
2. Chlorine residual summaries are also submitted quarterly. In addition to monthly
disinfection reporting, this water system must submit the monthly average of chlorine
residual samples taken in the distribution system. Distribution system chlorine residual
monitoring results are due quarterly by the same compliance dates as the monthly
disinfection report and must be submitted via the online form found at mrdl.utah.gov. Be
aware that the water system must maintain chlorine residual monitoring records for a
minimum of 5 years. [R309-105-17(1)]
System Name :
System # :
Prepared by :
Day Reading on
Water Meter
Totalizer
Volume of
Treated
Water
(gallons)
Setting of
Rotometer
Valve
Gross Weight of
Chlorine
Cylinder (lb)

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Monthly Total
0 Point of Entry
Residual
Distribution
System Residual
NOTE: These readings must be done a minimum of 3 times per week
Disinfectant Type:
Month:
Year:
Chlorinator Location:
MONTHLY AVERAGES :

Chlorine Gas
Point-of-
Entry
Chlorine
Residual
DS Chlorine
Residual
(optional to
record here -
must enter on
online form )
Quarterly Report for DBP Rule Compliance:
Surface Water & Ground Water System Disinfection