DDW-2024-006372

195 North 1950 West • Salt Lake City, UT
Mailing Address: P.O. Box 144830 • Salt Lake City, UT 84114-4830
Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.utah.gov
Printed on 100% recycled paper
State of Utah

Department of
Environmental Quality

Kimberly D. Shelley
Executive Director

DIVISION OF DRINKING WATER
Tim Davis
Director

SPENCER J. COX
Governor

DEIDRE HENDERSON
Lieutenant Governor

September 12, 2023

Justin M Blackett
Nephi City
21 East 100 North
Nephi, Utah 84648

Subject: System-Specific Minimum Sizing Standards
Nephi City, System #12003, File #11525

Dear Justin Blackett:

Based on the water use data submitted to the Division of Water Rights (DWRi), the following
system-specific minimum sizing standards have been set for Nephi City:

Peak Day Source Demand per ERC (gal/day) – 1,404
Average Annual Demand per ERC (gal/yr) – 233,886
Equalization Storage per ERC (gal/day) – 641
Fire Storage (gal) – 60,000

These standards are effective as of the date of this letter. A summary of the water use data and
calculations used to set the minimum sizing standards is attached for your reference. The Division
plans to evaluate these standards every 3 years, or upon request.

Water System Background

The community water system for Nephi City serves approximately 5,952 people and 2,223
connections. The connections include 2,072 residential and 151 commercial. There are six active
sources including four wells and two springs. The sources are disinfected by two gas chlorination
treatment plants. There are also four storage tanks and one pump station.

Justin Blackett
Page 2 of 3
September 12, 2023

Minimum Sizing Standard Background

Per Utah Code 19-4-114, the information needed for the Division of Drinking Water (the
Division) to set system-specific minimum sizing standards may be based on water use data
submitted to the DWRi, or alternatively, a community water system can submit an engineering
study to the Division if the water system’s water use data is not representative of future use or the
water system does not yet have actual water use data.

Actual water use data was available through DWRi and an engineering study was not submitted to
the Division for review. Therefore, the Division analyzed the submitted DWRi water use data and
sent a draft summary of the resulting system-specific minimum sizing standards to your office on
September 8, 2023. The Division allowed time for your water system to review the draft system-
specific minimum sizing. Your office replied on September 11, 2023, to verify the draft sizing
standards are representative. Therefore, the Division is setting system-specific minimum sizing
standard for Nephi City water system.

Water Use Data Definitions

Peak Day Source Demand is the total flow into a public water system to meet the demand of the
water system on the day of highest water consumption in a calendar year.

Average Annual Demand is the total quantity of drinking water flowing into a public water system
within a calendar year.

Total Equivalent Residential Connections (ERCs) term represents the number of residential service
connections and the number of equivalent residential connections for non-residential connections
(commercial, industrial, institutional connections).

Minimum Equalization Storage requirement is a volume that is equivalent to the amount of water needed to
meet the average day culinary demand for public water systems. Equalized storage per ERC is calculated
by dividing the Average Annual Demand per ERC data by the number of operational days in a year.

Fire Storage was set based on information from the Nephi Fire Department on September 11, 2023.

Storage Capacity

Based on your systems storage facilities and the storage minimum sizing requirement established in this
letter, your system is compliant with the minimum storage capacity requirements.

Source Capacity

The Division has documentation of established safe yields for all of your system sources. Using
total system wide safe yields and the source minimum sizing requirement established in this letter
indicates your water system is compliant with minimum source capacity requirements.

Justin Blackett
Page 3 of 3
September 12, 2023

If you have any questions regarding this letter, please contact Chris Martin, of this office, at
[phone], or Michael Newberry, Engineering Manager, at [phone].

Sincerely,

Michael Newberry, P.E.
Engineering Manager

CM/mrn/mdb

Enclosures
1. Utah Department of Environmental Quality Division of Drinking Water Minimum Sizing Standards
Summary Report

cc: Eric Larsen, Central Utah Health Department, [e-mail]
John Chartier, [e-mail]
Justin Blackett, Nephi City, [e-mail]
Chris Martin, Division of Drinking Water, [e-mail]
Curtis Park, Nephi Fire Department, [e-mail]
Ted Black, Office of the State Fire Marshal, [e-mail]

DDW-2022-034314

Utah Department of Environmental Quality
Division of Drinking Water
Minimum Sizing Standards
Date Standard Effective: Mon Sep 11 14:16:44 MDT 2023
Peak Day Source Demand per ERC (gal/day): 1,404
Average Annual Demand per ERC (gal/year): 233,886
Equalization Storage per ERC (gal/day): 641
NEPHI CITY PWS ID: UTAH12003
Admin Name: JUSTIN M BLACKETT
Address:
City, State, Zip: ,
Phone: [phone]
Email: [e-mail]
System Type: Community
Population: 6,443
MINIMUM SIZING STANDARD
MINIMUM SIZING STANDARD CALCULATIONS VARIABILITY
Data from these reporting years: 2021, 2022
Peak Day Source Demand per ERC (gal/day): 1,404
Average Annual Demand per ERC (gal/year): 233,886
Equalization Storage per ERC (gal/day): 641
x
x
x
(1 + 0.0)
(1 + 0.0)
(1 + 0.0)
=
=
=
1,404
233,886
641
DWRi WATER USE DATA REPORTED
Equalization per ERC (gal): 641
Existing Storage (gal): 5,580,000
ERCs: 3,998
Required Storage w/o Fire Flow: 2,562,718
Required Fire Storage (gal): 60,000
Required Storage w/Fire (gal): 2,622,718
Storage Deficiency: 0
Storage Deficiency (%): 0.0
No Storage Deficiency
Peak Day Source Demand per ERC (gpm): 0.98
Existing Source Capacity (gpm): 8,083
ERCs: 3,998
Required Source Capacity (gpm): 3,918
Source Deficiency: 0
Source Deficiency (%): 0.0
No Source Deficiency
Year Peak
Day
Source
Demand
(gal/day)
Average
Annual
Demand
(gallons)
ERCs Peak
Demand
per ERC
(gal/day)
Avg
Annual
Demand
per ERC
(gal/day)
Equaliza
tion
Storage
per ERC
(gal/day)
OP
Days
2022 4,679,220 818,580,072.63 3,998 1,170 204,751 561 365
2021 5,399,351 899,655,059.94 3,847 1,404 233,886 641 365
Variability:0.039 0.0 0.0 0.0
Year Peak Month Average
(gal/day)
Peak Month Average
per ERD (gal/day)
Ratio of PD/ERC to
Peak Month Avg/ERC
2022 4,237,849 1,060 1.1
2021 4,290,805 1,115 1.26
CAPACITY CALCULATIONS FOR STORAGE
CAPACITY CALCULATIONS FOR SOURCES
SYSTEM STORAGE AND SOURCE INVENTORY
Storage ID Storage Name Effective Volume (GAL)
ST001 SILVER TANK 600,000
ST002 BLUE TANK 2,000,000
ST003 EAST 1.5 MILLION GALLON TANK 1,490,000
ST004 SOUTH 1.5 MILLION GALLON TANK 1,490,000
Storage Totals: 5,580,000 GAL
Source ID Source Name Flow Rate (GPM)
WS003 EQUIPMENT SHED WELL 2,350
WS005 JONES WELL 2,600
WS010 FIRE STATION WELL REPL-1 2,400
WS011 WORWOOD WELL 733
Source Totals: 8,083 GPM