DDW-2025-003869

April 23, 2025
Justun Dave Edwards
Herriman City Water Department
5355 West Herriman Main Street
Herriman, Utah 84096
Subject:Plan Approval, 2 MG Zone 2 E Tank (ST010), 2 MG Zone 3 E Tank (ST011), Zone 2 &3 E Pump Station (PF008) and Zone 2 & 3 E On-Site Hypo chlorination (TP009) Herriman City Water
System; System #18157, File #12411
This letter supersedes the Plan Approval letter previously issued on June 04, 2021
Dear Justun Edwards:The Division of Drinking Water (the Division) received the updated version of plans and specifications for the proposed 2 MG Zone 2 E Tank (ST010), 2 MG Zone 3 E
Tank (ST011), Zone 2 &3 Pump Station (PF008) and Zone 2 & 3 E On-Site Hypo chlorination (TP009) project from your consultant Andrew McKinnon of Bowen Collins and Associates on April
04, 2025. The Division previously approved plan approval for this project on June 04, 2021. Per a conversation with Andrew McKinnon on April 15, 2025, the significant changes to the
plans for this project were necessitated because of property acquisition and developer coordination issues. The property for the previously approved tank sites became unavailable for
development within the next 10 years. This necessitated relocating the tanks to more suitable property for timely construction. This project has met the conditions for receiving superseded
plan approval.Our understanding of the project is as follows:2 MG Zone 2 E Tank (ST010), 2MG Zone3 E Tank (ST011)
Herriman City is proposing to construct two new 2 MG water storage tanks to support drinking water demands in developing areas at the east and southeast end of its service area. The
approximate address for 2 MG Zone 2 Tank (ST010) is 3400 West 15800 South and 2 MG Zone 3 Tank (ST011) is 3900 West 15700 South. The two tanks will serve new pressure zones in the city

and will primarily serve drinking water demands. Water for the two new tanks will be delivered via a new Zone 2 & 3 E Pump Station (PF008) that will be drawn from its Zone 1 East 2 MG
Tank (ST009) which gets water from Zone 1 East Pump Station (PF007).
The proposed 2 MG Zone 2 Tank (ST010) and 2 MG Zone 3 Tank (ST011) are both below ground concrete tanks with inlet/outlet piping, appurtenances, site work, drain/overflow piping,
and piping connected to the proposed Zone 2 & 3 E Pump Station (PF008). The tank dimensions will be 130 feet inside diameter with a height of 22 feet (overflow to the bottom of tank).
Zone 2 &3 E Pump Station (PF008)
Zone 2 & 3 Pump Station (PF008) will be constructed near Zone 1 East 2 MG Tank (ST009) located at 3700 W 15400 S. The long-term plan for the pump station will include 3 vertical turbine
pumps rated at 75 HP which will deliver 1,050 gallons per minute (gpm) of water at a TDH of 164 feet to the 2 MG Zone 2 Tank (ST010). One of the three vertical pumps will be redundant
or will act as a backup. For the first 20 years of operation, the pump station will operate with 2 smaller pumps at 50 HP and 700 gpm. Similarly, there will be 3 vertical turbine pumps
rated at 250 HP which will deliver 2,200 gpm of water at a TDH of 281 feet to the 2 MG Zone 3 Tank (ST011). One of the three vertical pumps will be redundant or will act as a backup.
The early phase for the Zone 3 pumps will include two smaller pumps at 150 HP and 1,467 gpm. These pumps are fed by a 24-inch diameter pipe from the 2 MG Zone 1 East Tank (ST009) and
the delivery to the new tanks from the pumps are through 16- inch and 20-inch diameter ductile iron (DI) pipes.
Zone 2 & 3 E On-Site Hypchlorination (TP009)
The on-site sodium hypochlorite generation (OSHG) system (TP009) is located inside the Zone 2 & 3 Pump Station (PF008) and is designed around a PSI Technologies MICROchlor 80 pounds
per day system (TP010). The system contains a 360-gallon brine storage tank with a 1,500-gallon 0.8% sodium hypochlorite solution storage tank. The OSHG system includes an electrolyzer
equipped with four 20 PPD cells that have 14 Pass, 2" x 12" Active Surface, and 1.2 ASI.
The water in the 2 MG Zone 1 East Tank (ST009) already has a chlorine residual from the primary disinfection step that occurs prior to delivery from wholesaler, Jordan Valley Water Conservation
District (JVWCD, System 18027) source WS001. The concentration of the chlorine residual can vary in the 2 MG Zone 1 East Tank (ST009) based on flows, demand, etc. Since there is already
a chlorine residual present, the OSHG system (TP009) is designed to be a chlorine booster for the 2 MG Zone 2 Tank (ST010) and 2 MG Zone 3 Tank (ST011). As water is pumped from the Zone
2 & 3 Pump Station (PF008) to the 2 MG Zone 2 Tank (ST010) and 2 MG Zone 3 Tank (ST011) 0.8% sodium hypochlorite from the 1,500-storage tank will be dosed separately to the pump discharge
piping for Zone 2 and Zone 3. The OSHG system (TP009) has been designed to generate enough 0.8% sodium hypochlorite to provide an additional residual concentration of up to 2.0 mg/L
for the 2 MG Zone 2 Tank (ST010) and 2 MG Zone 3 Tank (ST011) in the event that no residual is present in the water from JVWCD (WS001).
The areas being served by the 2 MG Zone 1 East Tank (ST009), the 2 MG Zone 2 Tank (ST010), and the 2 MG Zone 3 Tank (ST011) are in the early stages of development and there is currently
no modeling available to calculate flows and demand. This is why the (OSHG) system (TP009) is being designed as a robust and flexible system to provide various options to match the future
growth in the area.
The plan review of the proposed Zone 2 & 3 on-site sodium hypochlorite generation (OSHG) system (TP009) has been completed according to the following:
The Zone 2 & 3 on-site sodium hypochlorite generation (OSHG) system (TP009) is designed to provide secondary disinfection for the water going to the 2MG Zone 2 Tank (ST010) and the 2
MG Zone 3 Tank (ST011).
Wholesaler 18027-JVWCD (WS001) already provides primary disinfection but due to flows, demand and distance required to transfer water to the 2 MG Zone 1 East Tank (ST009) it is possible
that chlorine decay may occur and therefore secondary disinfection has been proposed.
The Zone 2 & 3 on-site sodium hypochlorite generation (OSHG) system (TP009) will be an onsite generation process that converts brine solution to 0.8% sodium hypochlorite solution.
The 0.8% sodium hypochlorite solution will be added separately to the water in the pump discharge piping for Zone 2 and Zone 3.
The chlorinated water then enters the 2 MG Zone 2 Tank (ST010) and the 2 MG Zone 3 Tank (ST011)
The proposed 0.8% sodium hypochlorite solution for disinfection meets the ANSI/NSF 60 standard.
The 0.8% sodium hypochlorite solution will be stored in a 1,500-gallon tank (ANSI/NSF 61 certified) with spill containment.
The proposed design target dose at the chemical addition point is 1.0 mg/L or ppm (measured as free chlorine). The dose is based on a typical flow of 1,050 gallons per minute (gpm) to
the Zone 2 E 2MG Tank (ST010) and 2,200 gpm to the Zone 3 2MG E Tank (ST011).
The chlorine dose will be adjusted by separate flow paced dosing pumps (Grundfos DMH 102-10) with dosing range of 1.0 to 27.0 gallons per hour (gph). Dosing Range is adjusted by a flow
paced PID control.
The Grundfos DMH 102-10 pump will have a rated injection capacity in the range from 1.0 to 27.0 gph, or 24 to 648 gal/day.
The chlorine dosing pump will be electrically wired to the discharge piping to ensure dosing stops when there is no flow.
The target chlorine residual is a minimum 0.2 ppm at the furthest connection point in the distribution system per regulations.
Secondary Disinfection Requirements
The installation of Zone 2 & 3 E On-Site Hypchlorination (TP009) will be to provide secondary disinfection. Herriman City water system is required to demonstrate ongoing compliance with

the following secondary disinfection requirements:
Chlorine Residual ‒ Distribution System (DS001)
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]
The chlorine residual measured in the distribution system must not exceed the maximum residual disinfectant level (MRDL) of 4.0 mg/L (measured as free chlorine). [R309-200-5(3)(c)(iv)]
This water system is required to take a minimum of three (3) chlorine residual samples per weekat varying locations throughout its distribution system (DS001). [R309-105-10(1)(c)]
Take distribution system chlorine residuals in conjunction with total coliform sampling. [R309-215-10(3) and (4)]
Chlorine Residual ‒ Point of Entry to Distribution System (EP009)
The Point of Entry (POE) sampling location for the Zone 2 & 3 E On-Site Hypchlorination (TP009) will be on the transmission line located 10 feet from the injection point inside the building.
This POE sampling location is identified as EP009 in the Division’s database.
This water system is required to maintain a minimum of 0.2 mg/L residual (measured as free chlorine) at the POE sampling location. [R309-215-5(3) and R309-215-10(2)]
The chlorine residual measured at the POE sampling location must not exceed the maximum residual disinfectant level (MRDL) of 4.0 mg/L (measured as free chlorine). [R309-200-5(3)(c)(iv)]
This water system will be required to record and report the free chlorine residual at the Zone 2 & 3 E On-Site Hypochlorination (TP009)POE sampling location (EP002) a minimum of daily
and include the readings in the water system’s disinfection reports. [R309-210-10(1)]
Please be aware if any water source of the Herriman City water system is found to require primary disinfection in the future per R309-200-5(7)(a)(i), additional regulations will apply.
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.
We have completed our review of the plans and specifications, stamped and signed by Eric W. Neil, P.E., and dated November 22, 2024,and find they basically comply with the applicable
portions of Utah’s Administrative Rules for Public Drinking Water Systems in R309. On this
basis, the plans for 2 MG Zone 2 E Tank (ST010), 2 MG Zone 3 E Tank (ST011), Zone 2 &3 E Pump Station (PF008) and Zone 2 & 3 E On-Site Hypochlorination (TP009)are hereby approved.
This approval pertains to construction only. An Operating Permit must be obtained from the Director before 2 MG Zone 2 E Tank (ST010), 2 MG Zone 3 E Tank (ST011), Zone 2 &3 E Pump Station
(PF008) and Zone 2 & 3 E On-Site Hypochlorination (TP009)may be put in service. A checklist outlining the items required for operating permit issuance is enclosed for your information.Approvals
or permits from the local authority or the county may be necessary before beginning construction of this project. As the project proceeds, notice of any changes in the approved design,
as well as any change affecting the quantity or quality of the delivered water, must be submitted to the Division. We may also conduct interim and final inspections of this project.
Please notify us when actual construction begins so that these inspections can be scheduled.
This approval must be renewed if construction has not begun or if substantial equipment has not been ordered within one year of the date of this letter.
If you have any questions regarding this approval, please contact Nagendra Dev, P.E.,of this office, at [phone], or me at [phone].
Sincerely,
Michael Newberry, P.E.
Permitting and Engineering Support Manager
ND/mrn/mdb
Enclosure ─ Operating Permit Checklistcc: Matthias Neville, Salt Lake County Health Department, [e-mail] Edwards, Herriman City, [e-mail] Jonathan Bowers,
Herriman City, [e-mail] Andrew McKinnon, Bowen Collins & Associates, [e-mail] Rogers, Bowen Collins & Associates, [e-mail] Berger,
Division of Drinking Water, [e-mail] Treutel, Division of Drinking Water, [e-mail] Dev, P.E., Division of Drinking Water, [e-mail] Superseded PA
Tanks, Chlorinator & Pump Station 18157 12411
Utah Division of Drinking Water ― Checklist for Issuing Operating PermitsWater System Name:System Number: Project Description:File Number:
Items 1 through 8 below must be submitted to the Division and found to be acceptable prior to operating permit issuance (unless a water line project meets the requirements of R309-500-7
and is not required to obtain an Operating Permit).
Distribution lines (not including in-line booster pump stations) requiring Plan Approval may be placed into service prior to submitting all of the following items and receipt of Operating
Permit if the water system has received items 1 and 4 below.☐1.Certification of Rule Conformance by a professional engineer (P.E.) that all conditions of Plan Approval were accomplished,
and if applicable, changes made during construction were in conformance with rules R309-500 through 550☐2.As-built or record drawings incorporating all changes to approved plans and
specifications (unless no changes were made to the previously approved plans during construction)☐3.Confirmation that as-built or record drawings have been received by the water system☐4.Satisfactory
bacteriological samples as evidence of proper disinfection and flushing in accordance with the appropriate ANSI/AWWA standards:
☐ANSI/AWWA C651-14 AWWA Standard for Disinfecting Water MainsTwo consecutive sample sets at least 16 hours apart, none positive (e.g., every 1,200 feet, end-of-line, each branch)☐ANSI/AWWA
C652-11 AWWA Standard for Disinfection of Water-Storage FacilitiesOne or more samples, none positive☐ANSI/AWWA C653-13 AWWA Standard for Disinfection of Water Treatment PlantsTwo consecutive
samples per unit, none positive, no less than 30 minutes apart☐ANSI/AWWA C654-13 AWWA Standard for Disinfection of WellsTwo consecutive samples, none positive, no less than 30 minutes
apart☐5.Water quality data, where appropriate [For example, include raw and finished water data that demonstrate satisfactory performance of the treatment facility; sample should be
taken from a storage tank for residual volatile organic compounds after tank interior re-coating; etc.]☐6.If applicable, all other documentation that may have been required during the
plan review process☐7.If applicable, confirmation that the water system owner has received the O&M manual for the new facility☐8.If applicable, location data of new storage tank, treatment
facility, or source