DDW-2024-006950

April 1, 2024
Annalee Munsey
Metropolitan Water District
3430 Danish Road
Cottonwood Heights, Utah 84093
Subject:Conditional Plan Approval, Exception to R309-550-7(1) Minimum Separation Requirements, Cottonwoods Connection Phase I Transmission Pipes;
Metropolitan Water District, System #18016, File #13606
Dear Annalee Munsey:The Division of Drinking Water (the Division) received the plans and specifications for the proposed Cottonwoods Connection Phase 1 Transmission Pipeline from Kelly
Stevens on January 17, 2024. Written review comments were provided to your consultant on January 29, February 28, and February 29, 2024. This project has met the conditions for receiving
a conditional plan approval.
On January 17, 2024, the Division of Drinking Water (the Division) also received your request and a completed Plan Review Checklist — Minimum Separation Standards for Water and Sewer
Linesfor an exception to Rule R309-550-7(1), Separation of Water Mains and Transmission Lines from Sewers and Other Pollution Sources for 18 sewer/water crossings along the Cottonwood
Connection transmission pipeline. This rule states specifically that the horizontal distance between pressure water mains and sanitary sewer lines shall be at least ten feet and that
where a main and a sewer line must cross, the water main shall be at least 18 inches above the sewer line.
Plan Approval
Our understanding of the project includes the following:
The purpose of the Cottonwoods Connection Phase 1 Transmission Pipeline is to regionalize treatment operations during the reconstruction of the Big Cottonwood Water Treatment Plant (BCWTP,
Sys#18026 TP001). Currently, the Big Cottonwood Water Treatment Plant receives raw water from Big Cottonwood Intake (Sys#18026, WS001) and conveys finished water to the Big Cottonwood
Conduit, which is a part of DS001, for distribution. During the reconstruction of BCWTP, raw water from Big Cottonwood Creek will be pumped through new pipes to the Little Cottonwood
Water Treatment Plant (LCWTP, Sys#18016, TP002) for treatment. The new pipes include Cottonwood Connector 1 (CC1), Salt Lake Aqueduct Replacement (SLAR), and Cottonwood Connector 2 (CC2).
Finished water from LCWTP will be conveyed through the existing Little Cottonwood Conduit to Big Cottonwood Conduit. This Plan Approval concerns the Cottonwoods Connection Project Phase
1 only and does not include Phase 2 or Phase 3. During Phase 2, LCWTP is proposed to be rebuilt. Raw water, normally treated at LCWTP, is proposed to be conveyed from LCWTP to BCWTP
via CC2, SLAR, and CC1. During Phase 3, finished water is proposed to be conveyed through CC1 and SLAR.
Installation of CC1 will convey raw water through 4,547 LF of 36-inch diameter welded steel pipe from BCWTP to SLAR and cross the Wasatch Fault Line.
Installation of SLAR will convey raw water through 13,823 LF of 60-, 66-, and 72-inch diameter welded steel pipe and will connect CC1 to CC2. The SLAR includes turnout tees and vaults
for future connections. Connection of these turnouts is not approved as a part of this Plan Approval.
Installation of CC2, will convey raw water through 1,905 LF of 36-inch diameter welded steel pipe and connect CC2 to LCWTP.
Installation of four vaults, including the SLAR/CC-1 Mechanical Connection Vault, SLAR/CC-2 Mechanical Connection Vault, McEntire Turnout Loop/Connection Vault, and 7000S Turnout Loop/Connection
Vault.
Documents involving Phase 2, Phase 3, the pump station at BCWTP, the connection of turnouts, extension of SLAR to the Terminal Reservoir, and the repair of SLA were not reviewed in the
scope of this Plan Approval.
We have completed our review of the plans and specifications, stamped and signed byJeremy Williams, dated January 3, 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 construct Cottonwoods Connection Phase 1 Transmission
Pipeswith the following condition:
Provide a means of chamber drainage at the McEntire Turnout and 7000 S Turnout per R309-550-6(7)(b) by March 25, 2025.
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 Cottonwoods Connection Phase 1 Transmission Pipes 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 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 R309-550(7)(1) – Minimum Separation Requirements
The Cottonwoods Connection Phase 1 Transmission Pipeline project involves the installation of 20,275 LF of welded steel pipe ranging from 36 inches to 72 inches in diameter. The immediate
purpose of these pipelines is to transmit raw water and is being considered for transmitting finished water in the future. The soil along the pipe zone is granular and free-draining.
No groundwater was observed in or near the pipe zone.
On January 30, 2024, February 14, 2024, and March 8, 2024, the Division of Drinking Water (the Division) received your request for an exception to Rule R309-550-7(1), Separation of Water
Mains and Transmission Lines from Sewers and Other Pollution Sources for 18 sewer/water crossings. This rule states specifically that the horizontal distance between pressure water
mains and sanitary sewer lines shall be at least ten feet and that where a main and a sewer line
must cross, the water main shall be at least 18 inches above the sewer line.
The basis for your request for an exception to R309-550-7(1) is that the proposed 60-inch, 69-inch, and 72-inch diameter water lines must cross under sewer lines or within 18 inches
at several locations due to existing utilities and limited space in the utility corridor. You propose the following measures to provide equivalent protection for public health:
The water line will be welded steel pipe with a minimum thickness of 0.375 inches.
The pipe joints will be double-welded lap joints, meaning they will be welded on the inside of the pipe and the outside of the pipe. In some locations, the pipe joints will be full-penetration
butt welds.
Each joint will be tested before it is coated and buried.
The pipeline will be continuous.
A cathodic protection system will be installed to minimize corrosion.
The steel cylinder design will provide pipeline integrity up to a vacuum of -11 psi.
Sewer lines within 18 inches of vertical clearance of water lines will be encased in concrete.

On this basis, an exception to R309-550-7(1), Separation of Water Mains and Transmission Lines from Sewers and Other Pollution Sources, is hereby granted for specific locations.This
exception may be rescinded at 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.
Please maintain a copy of this letter with your permanent records for future reference.
If you have any questions regarding this conditional plan approval, please contact Rebecca Yoo, of this office, at [phone], or me at [phone].
Sincerely,
Michael Newberry, P.E.
Permitting and Engineering Support Manager
RY/mrn/mdbEnclosures –Operating Permit ChecklistException Request Spreadsheet – Minimum Separation Standards for Water and Sewer Lines by Maggie Shalvoy, Received on March 8, 2024cc:Matthias
Neville, Salt Lake County Health Department, [e-mail] Williams, Hazen and Sawyer, [e-mail] Shalvoy, Hazen and Sawyer, [e-mail]
Annalee Munsey, Metropolitan Water District of Salt Lake and Sandy, [e-mail] Yoo, Division of Drinking Water, [e-mail]
Nagendra Dev, Division of Drinking Water, [e-mail] 18016 13606 Conditional PA Transmission System
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