DDW-2025-003216

Mz. T Allen <[e-mail]>
Fwd: (EXTERNAL) Re: Salt Lake City Public Utilities System Specific Minimum
Sizing Requirements
1 message
Julie Cobleigh <[e-mail]>Mon, Mar 31, 2025 at 1:03 PM
To: "Mz. T Allen" <[e-mail]>
Hi Mz. T,
Could you update the population in SDWIS for SLC, System 18026, to 381,174 per their comments below?
Thanks!
Julie
Julie Cobleigh, P.E.
Engineer | Permitting
P: [phone]
drinkingwater.utah.gov
Emails to and from this email address may be considered public records and thus subject to Utah GRA
On Fri, Mar 28, 2025 at 10:28 AM Gray, Teresa <[e-mail]> wrote:
Hello Julie,

Thank you for your excellent work on this. We truly appreciate our discussions and your willingness to
delve into these topics, ensuring they align with our system needs and are executed correctly.
Additionally, we appreciate you catching the issue with the wholesale water data. Since the figures were
pulled from the database and had already been double-checked, we did not scrutinize the total number as
closely as we should have. We fully support the proposed change.
This adjustment has a minor impact on our requested variability factors. Since our planning values are
based on historical years outside the three-year window under consideration (for all the reasons
previously discussed), they remain unchanged despite the modifications to reported historic use in 2021.
As a result, to maintain the same final minimum sizing standards, slight adjustments to the variability
factors are necessary.
Since peak day usage has not changed, no modification is needed for the peak day variability factor.
We request that the average annual variability factor be updated from 23.5% to 28.8% to maintain
the City’s sizing standard of 196,000 gallons per year.
We request that the equalization storage variability factor be updated from 61.7% to 68.6% to
maintain the City’s sizing standard of 703 gallons.
Additionally, the draft data table is accurate except for the population figure. Currently, it lists a
population of 360,654, but our records indicate:
2023 Population: 378,838
Caution: This is an external email. Please be cautious when clicking links or opening attachments.
2024 Population: 381,174
Please update the data accordingly.
Let us know if you have any concerns regarding these proposed adjustments. We appreciate your time and
effort on this.
Best regards,

TERESA GRAY, LEHS
Water Quality and Treatment Administrator
DEPARTMENT of PUBLIC UTILITIES | SALT LAKE CITY CORPORATION
Office: [phone] | Mobile: [phone]
Email: [e-mail]
WWW.SLC.GOV/UTILITIES WWW.SLC.GOV

Please note that my email address is now [e-mail].
My [e-mail] address will be forwarded and continue to work for now, but please update
my information in your records.

From: Julie Cobleigh <[e-mail]>
Sent: Tuesday, February 11, 2025 12:55 PM
To: Prue, Tamara <[e-mail]>
Cc: Briefer, Laura <[e-mail]>; Stewart, Jesse <[e-mail]>; Gray, Teresa
<[e-mail]>; Draper, Jason <[e-mail]>; Keith Larson
<[e-mail]>; Denning, Pat <[e-mail]>
Subject: (EXTERNAL) Re: Salt Lake City Public Ulies System Specific Minimum Sizing Requirements

Hi Everyone-

I've attached a draft of the new System-Specific Minimum Sizing Standard for Salt Lake City, using water use data
provided to DWRi for 2021-2023 and a system requested variability. Please take a thorough look at the draft and let me
know if you are in agreement before it is finalized.

A couple things to point out:
Please review the storage tanks listed for accuracy, along with the contract amount included for MWSDSL of
87,470,000 gallons based on the last standard.
The average annual demands are slightly less than what you have included in your letter, which was based on
the original table I sent. This was an error in our table as it pulled in the wrong data from DWRi (it was including
wholesale volumes). The calculations were done correctly in our tables, but it was displaying the wrong data
set. This draft shows the actual average annual demands for each year, not including wholesale volumes (per
DDW guidance policy, wholesale demands are not included in the per ERC sizing standard calculations).
Let me know if you have any questions.

Thanks!
Julie
Julie Cobleigh, P.E.
Engineer | Permitting
P: [phone]
drinkingwater.utah.gov
Emails to and from this email address may be considered public records and thus subject to Utah GRA

On Wed, Jan 29, 2025 at 3:59 PM Prue, Tamara <[e-mail]> wrote:
Hello Julie,

As you know our department has been working to resolve issues you brought up with the ERC calculation and
variability factors. Please see the attached document for our specific requests relative to updating system sizing
requirements for our facilities.

I’ll be sending an email to Division of Water Rights to update our 2021-2023 ERC values.
Feel free to reach out to myself, Teresa, or Keith if you have any questions.

Tamara Prue
Water Resource Manager
DEPARTMENT of PUBLIC UTILITIES | SALT LAKE CITY CORPORATION
1530 South West Temple, Room 234
Salt Lake City, UT 84115
Office: [phone]
Cell: [phone]
Email: [e-mail]
WWW.SLC.GOV/UTILITIES WWW.SLC.GOV

18026 (3).pdf
512K