DDW-2025-005781

J. Paul Wright <[e-mail]>
Quail Mesa Subdivsion - Virgin Town Water System (File #18323)
Zachery Isaac <[e-mail]>Mon, Jun 23, 2025 at 4:32 PM
To: "J. Paul Wright" <[e-mail]>, "[e-mail]" <[e-mail]>
Cc: Brandee Walker <[e-mail]>, "[e-mail]" <[e-mail]>, "Beers,
Robert" <[e-mail]>, Jean Virgin Krause <[e-mail]>, Rod Mills <[e-mail]>
Paul,

See below for the answers from Civil Science (red) regarding this review.

1. Could you let me know the length of pipe, pipe size and pipe type that will be added to the water system as a part
of this project (ie, 1,000 LF of 12-inch PVC C-900 pipe)
Approximately 354 L.F of 8” C-900 and 2,523 L.F of 12” C-900 will be installed.

2. In the water report that shows the results of the hydraulic modeling, you indicated that for the fire flow + peak day
demand scenario, the minimum pressure is 20.2 psi with 1,000 gpm of fire flow at Node J-21, but in the Table of
results in Appendix B, Node J-22 actually shows a pressure of 15.88 psi, which is lower than 20 psi. The
requirement is that all nodes need to be 20 psi or above. This would then allow a fire flow lower than 1,000 gpm.
This should be explained or a letter from the fire authority allowing a lower fire flow needs to be submitted.
This hydrant was added at the end of the line as a comment from the previous town engineer to address the
concern of not being able to flush the dead-end line. This hydrant will not be used for fire protection and is called
out on the construction drawings to be marked for water line flushing only. The fire hydrant located between lots 9
& 8 will provide the fire protection, as Hurricane Valley Fire’s preference is to not locate hydrants for fire
protection at the end of dead-end streets.

3) Sheet C8 of the plans shows a couple of standard trench details. The following items have not been detailed in the
plans, nor could I find them in the standard specifications:
a) The pipe zone backfill soil material needs to be specified. For plastic pipe, this needs to be at least 3/4" minus material
A note has been added to the utility plan on sheet C2 that calls out the material sizing. (note #2 “waterline
standards & specifications)
b) The required burial depth for the pipe has not been specified.
A standard bury depth of 3’ has been used as the minimum for this project. This note has been added to sheet
C2. (note #3 “waterline standards & specifications)

3. It appears the standard specifications describe the water/sewer line separation requirements on Sheet 14. I just
want to make sure that is referenced in the plans to ensure those separation requirements are met. Any deviation
from this may require an exception from the Division of Drinking Water.
A minimum vertical separation of 18” of separation between water and sewer lines has been followed as required
by Ash Creek. This note has been added to sheet C2. (note #4 “waterline standards & specifications)

6/26/25, 4:22 PM State of Utah Mail - Quail Mesa Subdivsion - Virgin Town Water System (File #18323)
https://mail.google.com/mail/u/0/?ik=f3bcb897f8&view=pt&search=all&permmsgid=msg-f:1835760822360479153&simpl=msg-f:1835760822360479153 1/3
5) I saw that disinfection requirements were specified in the standard specs, but pressure testing requirements were only
mentioned and I could not find where pressure testing is explicitly described (methodology, pressure testing requirements,
etc.). Please add this to the specifications or show where that is outlined.
Rod, could you help us update the town of Virgin specs to describe the pressure testing requirements?
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--
J. Paul Wright, P.E. | District Engineer | Southwest Utah District
435.986.2590 (office) | 435.680.0163 (cell) | 435.986.2595 (fax)
620 S 400 E #400, St. George, UT 84770
DEQ WEBSITE
Emails to and from this email address may be considered public records and thus subject to Utah
GRAMA requirements.

--
J. Paul Wright, P.E. | District Engineer | Southwest Utah District
435.986.2590 (office) | 435.680.0163 (cell) | 435.986.2595 (fax)
620 S 400 E #400, St. George, UT 84770
6/26/25, 4:22 PM State of Utah Mail - Quail Mesa Subdivsion - Virgin Town Water System (File #18323)
https://mail.google.com/mail/u/0/?ik=f3bcb897f8&view=pt&search=all&permmsgid=msg-f:1835760822360479153&simpl=msg-f:1835760822360479153 2/3