DDW-2024-010023

August 15, 2024
Darren Hess
Weber Basin Water Conservancy District
2837 UT-193
Layton, Utah 84041
Subject:ConditionalPlan Approval, So. Weber Well 2 Re-equipping (WS004), Chlorination Type Change at So. Weber Well 2 NaOCl and F- (TP004), and Temporary Exception to R309-520-7(1)(c)(i)Chlorine
Feed Capacity;
Weber Basin WCD - Central, System #29023, File #13638This temporary exception expires on August 31, 2027.
Dear Darren Hess:The following is a summary of the Division’s review of this project:The Division of Drinking Water (the Division) received the plans and specifications for So. Weber
Well 2 Re-equipping and the So. Weber Well 2 NaOCl and F- (TP004) from your consultant, Michael McFadden, P.E., with Bowen, Collins and Associates on February 27, 2024. Written review
comments were provided to your consultant on March 28, 2024. The Division received the revised plans and specifications and responses to review comments on April 24, 2024Additional review
comments were provided to your consultant on May 9, 2024.The Division received an exception request to R309-520-7(1)(c)(i) Chlorine Feed Capacity on June 4, 2024. The Division requested
further information to justify the exception on June 13, 2024.The Division received the requested information on June 20, 2024. Further information was received on July 9, 2024, and
August 5, 2024.This project has met the conditions for receiving a plan approval.
The letter includes the following sections and addenda:

Project Summary for Re-equipping So. Weber Well 2 (WS004)
Project Summary for So. Weber Well 2 NaOCl and F- (TP004)    
Conditional Plan Approval for So. Weber Well 2 Re-equipping (WS004) and Chlorination Type Change at So. Weber Well 2 NaOCl and F- (TP004)
Exception to Rule R309-520-7(1)(c)(i) Chlorine Feed Capacity 
Secondary Disinfection Requirements
Operating Permit Checklist 
FutureMonitoring and Reporting Requirements (Addendum 1)Project Summary for Re-equipping So Weber Well 2 (WS004)
Between June and August 2021, So. Weber Well 2 was cleaned, video inspected, test pumped and disinfected. After the rehabilitation was complete, the well was inactivated, and a temporary
well cap installed in anticipation of this project to rebuild the well house and re-equip the well.
Our understanding of this project is that the well will be equipped with a new 4,500 gallon per minute (gpm) pump and variable frequency drive. The new 16-inch diameter well discharge
piping will also include a 10-inch diameter pump-to-waste line and a 8-inch diameter pressure relief line. A new well house will be built to house the well head, discharge piping, and
new on-site hypochlorite generation system. Water from the well will be chlorinated within the new well house, then flow to the nearby, existing fluoridation building before entering
the distribution system.This well is identified as WS004 in the Division’s database.Project Summary for Chlorination Type Change at So. Weber Well 2 NaOCl and F- (TP004)
Our understanding is the project will include construction of a new onsite hypochlorite generation facility, which will replace the existing chlorine gas facility. The new onsite hypochlorination
facility, formerly named So. Weber Well 2 Cl2 Gas and F-, is now identified as So. Weber Well 2 NaOCl and F- in the Division’s database.
The plan review of the proposed Chlorination Type Change at So. Weber Well 2 NaOCl and F- (TP004) has been completed according to the following:
The proposed chlorination system at So. Weber Well 2 NaOCl and F- is an onsite generation process that converts brine solution to sodium hypochlorite solution. The sodium hypochlorite
generation system will be a De Nora ClorTec 75 ppm system.
This chlorinator will add chlorine to the water from So. Weber Well 2 (WS004).
This chlorinator is intendedto continue to provide secondary disinfection in the distribution system in place of the gas chlorination facility it will replace.
The chlorinated water will go to the nearby fluoridation facility before entering the distribution system.
The proposed sodium hypochlorite generation system and chemicals for disinfection meets the ANSI/NSF 60 and 61 standards.
The proposed design target dose of 0.5 mg/L or ppm (measured as free chlorine) is based on a typical flow of 4,500 gallons per minute (gpm) from So. Weber Well 2.
The chlorine dose will be adjusted by an automatic flow-paced control.
The Point of Entry (POE) sampling location will be within the well house.
Conditional Plan Approval for So. Weber Well 2 (WS004) and Chlorination Type Change at So. Weber Well 2 NaOCl and F- (TP004)
We have completed our review of the plans and specifications, stamped, and signed byCristina Nelson, P.E., dated February 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, we hereby approve the proposed plans to re-equip So. Weber Well 2 and construct a new
sodium hypochlorite generation system at So. Weber Well 2 NaOCl and F-with the following conditions:
Collect updated Inorganics and Metals, Nitrate, Sulfate Sodium and TDS samples from Weber Well 2 (WS004) and submit the results to the Division.
You must fulfill and comply with the condition of approval,or this approval is invalid.
This conditional approval pertains to construction only. An Operating Permit must be obtained from the Director before So. Weber Well 2 and So. Weber Well 2 NaOCl and F- 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, a 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.
Exception to R309-520-7(1)(c)(i) Chlorine Feed Capacity
According to R309-520-7(1)(c)(i) Chlorine Feed Capacity, “the capacity of the chlorine feed equipment shall be sized to provide at least 2 mg/L during peak demand.” The basis for your
request for an exception to R309-520-7(1)(c)(i) is as follows:
The target chlorine residual within the distribution system is 0.5 mg/L.
The chlorinator is sized to yield 0.7 mg/L under all flow conditions from the well. The water system cannot foresee a scenario where they would elect to dose at a higher rate.
A chlorinator sized to meet the 2 mg/L dose specified in the rule would be impractical for meeting the target dose of 0.7 mg/L under expected flow conditions.

You propose to protect public health and to meet the intent of the rule based on the following:
As designed, the proposed chlorinator meets the other requirements of R309-520-7(1)(c)(i) including “the feed equipment shall operate accurately over the design feeding range” and, “the
feed equipment shall be designed to maintain a detectable residual at all times, at all points within the intended area in the distribution system”.
The water system’s other chlorinators operate with a dosing rate of 0.5 mg/L, with the exception of the Weber South Water Treatment Plant, where the target dose is 1 mg/L.
Based on distribution system chlorine residual data provided with your exception request, the chlorine residual within the distribution system is generally between 0.2 mg/L and 1 mg/L
at most locations.
On this basis, an exception to R309-520-7(1)(c)(i) Chlorine Feed Capacity is hereby granted for So. Weber Well 2 NaOCl and F- (TP004).
This Temporary Exception expires onAugust 31, 2027.
You will be required to re-submit an exception request along with confirmation that all conditions outlined in this temporary exception have been fulfilled and obtain an exception renewal
prior to August 31, 2027.
Exceptions granted by the Division include an expiration date to ensure that the basis and conditions for granting the exception are verified periodically and that the drinking water
quality remains protected. After receiving your request, the Division will determine whether this exception can be re-issued.
Failure to request the re-evaluation of this exception and obtain an exception renewal by August 31, 2027, will result in the activation of the deficiency related to not having adequate
means to maintain disinfectant residual in the water entering the distribution system.
This Temporary Exception may be rescinded any time if new evidence indicates that the conditions of this exception are no longer being met or a public health risk exists due to this
exception.
Secondary Disinfection Requirements
The plan review of the proposed So. Weber Well 2 NaOCl and F- (TP004) is based on providing secondary disinfection. When this chlorinator is installed and placed in operation after the
Operating Permit issuance, the Weber-Basin WCD- Central will be required to demonstrate ongoing compliance with the secondary disinfection requirements that are outlined in Addendum
1 to this letter.
The Division shall be informed by telephone within 8 hours by a water supplier ofthe 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 So. Weber Well 2 is found to requireadditionaldisinfection 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 have any questions regarding this temporary exception, please contact Hunter Payne, of this office, at [phone], or Michael Newberry, P.E., Permitting and Engineering Manager,
at [phone].
Sincerely,
Russell Seeley, P.E.
Assistant Director
HP/mrn/mdbEnclosures –Operating Permit ChecklistAddendum 1- Future Monitoring and Reporting Requirementscc:Scott Braeden, Weber-Morgan Health Department, [e-mail]
McFadden, P.E., Bowen Collins & Associates, [e-mail] Hess, Weber Basin Water Conservancy District, [e-mail] Payne, Division of Drinking Water,
[e-mail]
Luke Treutel, Division of Drinking Water, [e-mail]
David Kruse, Division of Drinking Water, [e-mail]
Jennifer Yee, Division of Drinking Water, [e-mail]
Sitara Federico, Division of Drinking Water, [e-mail]
Nagendra Dev, P.E., Division of Drinking Water, [e-mail]
hpayne 29023 13638 PA WS004 TP004 and Exception
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
Addendum 1
Future Elective Monitoring and Reporting Requirements
Chlorine Monitoring & Reporting Requirements
The water system will be required to meet elective disinfection requirements once this facility is installed and operating. As a part of these requirements, the water system will need
to continuously maintain a minimum free chlorine residual at each chlorinator Point of Entry (POE) into the system and demonstrate a detectable chlorine residual in the distribution
system.
Elective Disinfection Requirements and Reporting

Chlorine Residual ‒ Point of Entry (POE) to Distribution System
The POE sampling location will be identified in the Division’s database. The location will be identified during the plan approval 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)]
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)]Record
and report the lowest daily value of chlorine residual measured as free chlorine at the POE sampling location. [R309-215-10(1)]
Chlorine Residual ‒ Distribution System (DS001)
This water system must maintain a detectable residualthroughout 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 shall 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 must take a minimum of three (3) chlorine residual samples per weekat varying locations throughout its distribution system (DS001). [R309-105-10(1)(c)]
Distribution system chlorine residuals must be taken in conjunction with total coliform sampling. [R309-215-10(3)]
Disinfection Report Submission
To demonstrate ongoing compliance with elective disinfection requirements, the water system must complete monthly operational reports for each active chlorinator using a template approved
by the Division.
Operational reports are submitted quarterly. 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 10th for quarterly reports). The reports can be submitted by hardcopy, fax, or email at [e-mail]. Please contact Luke Treutel at [phone] or [e-mail]
to schedule training regarding proper reporting.
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 can be submitted via an online form found at mrdl.utah.gov.
Records must be maintained for a minimum of 5 years. [R309-105-17(1)]
Source Bacteriological Monitoring 
The operating permit will include requirements for monthly Escherichia Coli (E. Coli) sampling at So. Weber Well 2 (WS004), prior to any treatment for a minimum of two operating seasons.
This monitoring is required to evaluate the quality of the water coming from So. Weber Well 2 (WS004) to determine whether primary disinfection treatment is required or not. Additional
monitoring and/or disinfection requirements may be assigned depending on the results of the assessment monitoring.