DDW-2024-008320

6080 Fashion Point Dr. ● South Ogden, Utah 84403 ● [phone] ● www.jonescivil.com

MEMORANDUM

To: Division of Drinking Water

cc: Division of Water Rights

cc: Mark Johnson, Water Superintendent
South Weber City

From: Dana Q. Shuler, P.E.
City Engineer’s Office
Jones & Associates Consulting Engineers

RE: System Specific Source and Storage Minimum Sizing Requirements - REVISED
South Weber City (PWS UTAH06010)

Date: February 29, 2024
Revised: April 18, 2024

Background
In accordance with the original guidance provided from the Division of Drinking Water (DDW), water
systems were to measure the amount of water flowing into the distribution system, which was generally
considered to be the source flow minus tank overflows and pump to waste. As we understood, system
master meters were to be installed to measure the net flows into the distribution system.
Since South Weber City did not have these system master meters, they entered into a Corrective Action
Agreement with the DDW in order to have time to budget, design, and install the system master meters,
then collect and report the required three (3) years of data. Due to numerous delays, these meters are
just now installed and operable.
Data Gathering and Deficiencies
The new 2023 DDW guidance for determining minimum sizing instructs systems to use the source
meters to calculate the minimum sizing. Therefore, to the best of our ability, we have gathered the past
three (3) years of data from the City’s well #1 SCADA and records from Weber Basin Water Conservancy
District (WBWCD), a wholesale supplier to the City.
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6080 Fashion Point Dr. ● South Ogden, Utah 84403 ● [phone] ● www.jonescivil.com
The collected data has several gaps:
• The City’s new SCADA system was installed in early 2021. It wasn’t until then that daily readings
could be obtained for the well. Daily readings for the well start in February 2021; however, it
looks like correct daily readings didn’t start until the beginning of September 2021.
• WBWCD was unable to provide data for the Church Street Pump Station from 11/17/22 to
7/10/23. Additionally, the data from 7/11/23 to 7/31/23 looks suspect (abnormal peaks), and
the data after 8/1/23 appears low based on the historical data.
• WBWCD’s South Weber Well #2’s meter had to be replaced last year, so daily consumption
readings between 10/5/23 and 12/31/23 were unavailable.
Therefore, we used the best available data in order to determine the 2023 usage.
Annual Average Demand
The following Table 1 summarizes 1) the data reported/to be reported to the Division of Water Rights
(DWRi), 2) the DWRi determined ERCs, and 3) the maximum values for the past three (3) years.
Table 1 – Annual Demand Summary 2021-2023
Annual Demand

2021 2022 2023 2021-2023
Maximum
Reported/to be reported
to DWRi
ac-ft 664.37 730.32 624.13

DWRi ERCs

2,857 2,905 2,955

Average ERCs for reporting
year
2,802 2,881 2,930
Annual Average Demand ac-ft/ERC 0.237 0.253 0.213 0.253 ac-ft/ERC
gal/ERC 77,270 82,596 69,406 82,596 gal/ERC
Annual Average Daily
Demand
gpd/ERC 212 226 190 226 gpd/ERC
Equalization Storage gal/ERC 212 226 190 226 gal/ERC

Upon determining the maximum annual demand and comparing it to comparable cities, we found
226 gpd/ERC to be a low value for an average daily demand per ERC. Knowing that 2021-2023 contains
questionable data and gaps, we looked at a larger data range, going back to 2016. Table 2 contains the
historical data:

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6080 Fashion Point Dr. ● South Ogden, Utah 84403 ● [phone] ● www.jonescivil.com
Table 2 – Historic Annual Demand Summary 2016-2020
Historical Annual Demand

2016 2017 2018 2019 2020 2016-2020
Maximum
Reported/to be reported to DWRi ac-ft 614.47 642.51 740.98 655.23 711.11

DWRi ERCs

2,403 2,281 2,645 2,585 2,746

Average ERCs for reporting year 2,187 2,342 2,463 2,615 2,666
Annual Average Demand ac-ft/ERC 0.281 0.274 0.301 0.251 0.267 0.301 ac-ft/ERC
gal/ERC 91,546 89,389 98,024 81,642 86,926 98,024 gal/ERC
Annual Average Daily Demand gpd/ERC 250 244 268 223 238 268 gpd/ERC
Equalization Storage gal/ERC 250 244 268 223 238 268 gal/ERC
Peak Day Demand
Based on the best available data from the daily readings reported by the City’s and WBWCD’s SCADA systems, we have determined the
peak day source demands of each year and the maximum to be as follows:
Table 3 – Peak Day Source Demands 2021-2023
Peak Day Source Demand

2021 2022 2023 3-Year Maximum
Peak Day All Sources (excluding
wheeled water)
ac-ft 4.437 4.005 4.507

gallons 1,445,632 1,304,819 1,468,384
Average ERCs for current year 2,857 2,905 2,955

PDD per ERC gpd/ERC 506 449 497 506 gpd/ERC
Date

1/16/2021 10/17/2022 6/5/2023 1/16/2021
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6080 Fashion Point Dr. ● South Ogden, Utah 84403 ● [phone] ● www.jonescivil.com
System-Specific Variability Factor
Due to the sporadic nature of the data over the past few years, we feel that the more reliable data is the
historical data from 2016 to 2020 related to the annual average demand. However, without daily reads
prior to 2021, the peak day source demand can only be calculated from the incomplete 2021-2023 data.
Interestingly, the peak day occurred in January of 2021. That is unusual, and, therefore, suspect.
Without good current data, we respectfully request that the system be permitted to use a system-
specific variability factor until such time as several years of reliable data is logged.
Calculating the variability amongst the data points from 2021-2023, we find the following:
Average Annual Demand Variability (2021-2023) =0.253−0.213
0.213 =18.8%
Peak Day Source Demand Variability (2021-2023) =506−449
449 =12.7%
As a temporary, more conservative approach, we recommend using the higher of the two (2) calculated
variability factors.
Proposed System-Specific Sizing Values
Based on the above presented data and reasoning in the above paragraph, we propose the following
system-specific source and storage minimum sizing requirements for the South Weber City Water
System until such time as more reliable and accurate data can be collected and processed:
Parameter 2021-2023 Max Value System-Specific
Variability Factor
Proposed System-
Specific Value
Annual Average Demand
per ERC
82,596 gal/ERC (226
gpd/ERC)
0.253 ac-ft/ERC
18.8% 98,124 gal/ERC
(268 gpd/ERC)
0.283 ac-ft/ERC
Equalization Storage 226 gal/ERC 18.8% 268 gal/ERC
Peak Day Source Demand
per ERC
506 gpd/ERC 18.8% 601 gpd/ERC

Consecutive Connections
Currently, South Weber receives its water from three (3) sources: a city-owned well and two (2)
connections to Weber Basin Water Conservancy District.
The current production rate of these sources is as follows:

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6080 Fashion Point Dr. ● South Ogden, Utah 84403 ● [phone] ● www.jonescivil.com
Source Pump Capacity Allowable Source
Production Rate1
GPM MGD GPM MGD
Weber Basin Connection #1 (700 East) 3,000 4.320 1,388 1.998 Weber Basin Connection #2 (Church St) 700 1.008
Totals 3,700 5.328 1,388 1.998
1to avoid Peaking Charge
Based on the number of ERCs at the end of 2023 and using the proposed peak day source demand per
ERC, we find that:
2,955 𝐶𝑅𝐶𝑠 𝑥 601 𝑔𝑝𝑑
𝐶𝑅𝐶=1,775,955 𝑔𝑝𝑑 =1,233 𝑔𝑝𝑚= 1.776 𝑀𝐺𝐶
Fire Storage
South Weber’s fire marshal has determined the requirement of 1,750 gpm for 2 hours, or 210,000
gallons for fire storage.

We are happy to provide a copy of the daily source data, any calculations, and/or any other
documentation upon request.
If you have any questions, please feel free to contact me. My contact information is:
Dana Q. Shuler, P.E.
Jones & Associates
[phone]
[e-mail]