DDW-2025-004514

May 1st, 2025
Midvale City Water System
8196 S 700 W
Midvale City, Utah 84047
Dear Wesley Vanvalkenburg:
Subject: Notification for Elective Disinfection Requirements –
Midvale City Water System & UTAH18017, Million Gallon Well (WS001), Oak
Street Well (WS005), and Hancock Replacement Well (WS008)
The Division of Drinking Water records indicate that you are the responsible party for the
Midvale City Water System. The Midvale City Water System water system is a public water
system and thus subject to the Administrative Rules for Public Drinking Water Systems.
Starting in August 2023, Midvale City Water System began source assessment sampling at
Million Gallon Well (WS001), Oak Street Well (WS005), and Hancock Replacement Well
(WS008) as part of a conditional plan approval letter for a chlorinator. Source Assessment
sampling has been completed. Results of sampling are below.
Facility Name/ID Number of Samples Sample Results
Million Gallon Well
(WS001)
44 Total Coliform absent
Oak Street Well (WS005) 21 Total Coliform absent
Hancock Replacement Well
(WS008)
34 Total Coliform absent
Elective Disinfection Requirements
Based on these source assessment monitoring results, the water system is not required to disinfect.
While the Division is not requiring the Midvale City Water System to disinfect, because you have
Wesley Vanvalkenburg
Page 2
elected to chlorinate and install the Oak Street Chlorinator (TP005) and the Hancock Chlorinator
(TP008), Midvale City Water System is required to demonstrate ongoing compliance with
elective disinfection requirements once the water system has received operating permits for
the chlorinators. These requirements are outlined in the included Addendum A, and
compliance with them, including the requirement to maintain detectable chlorine residuals
throughout the distribution system for secondary disinfection, is mandatory . These
requirements will also be included in the operating permit letter(s) for the chlorinators. Please
contact Luke Treutel at [phone] or [e-mail] with any questions relating to
disinfection monitoring and reporting requirements.
Midvale City Water System must not discontinue chlorination without approval from the Division
of Drinking Water. Midvale City Water System must notify the Division by telephone at (801)
560-8456 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. (R309-105-18(1)(a)).
Please be aware that if per R309-200-5(7)(a)(i), Midvale City Water System is ever found to be
required to disinfect, further requirements will apply. For example, if primary disinfection is
required, this will require you to submit disinfection CT information showing compliance with
4-log virus inactivation in accordance with the Ground Water Rule in R309-215-16.
This notice serves as a courtesy to your water system. This notice is a compliance advisory, is not
an agency action, and does not trigger any legal rights and/or remedies for the System.
Additionally, nothing in this notice prevents the Director from initiating formal enforcement at
any time. We urge you to take action on this matter. Compliance with the standards and
regulations for drinking water, as outlined in the Utah Safe Drinking Water Act, the Utah Drinking
Water Rules, and the Federal Safe Drinking Water Act, is essential to ensure safe, reliable
drinking water and to protect public health. We are dedicated to working together with you to help
you come into compliance. If you require assistance in responding to this notice, please contact
Luke Treutel at [phone] or [e-mail] if you have any questions or need
technical assistance.
Wesley Vanvalkenburg
Page 3
Sincerely,
Mark Berger
Rules Section Manager
Enclosure: Addendum A - Elective Disinfection Monitoring and Reporting Requirements
Chlorinator Operational Report Template
cc: Wesley Vanvalkenburg, [e-mail]
Rob Larson, Salt Lake 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, Midvale City Water System 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 lowest daily value of chlorine level at the
point of entry (POE) to the distribution system. [R309-215-10(1)]
a. Our records show that the water system serves 33,005 people. Please be aware that
R309-215-16(3)(b)(iii)(A)(I) requires water systems serving greater than 3,300
people to continuously monitor the POE chlorine residuals. Therefore, an online
analyzer to continuously monitor the POE chlorine residuals entering the
distribution system is needed.
b. The POE sampling locations are identified as EP005 and EP008 in the Division’s
database. The specific locations will be identified during the operating permit
process. 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 Midvale City
Water System 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