DDW-2024-011799

SANDY
45 W 10000 S, STE 500
Sandy, UT 84070
P: 801.255.0529
LAYTON
919 North 400 West
Layton, UT 84041
P: 801.547.1100
CEDAR CITY
88 E Fiddler’s Canyon Rd, STE 210
Cedar City, UT 84721
P: 435.865.1453
TOOELE
169 N. Main St, Unit 1
Tooele, UT 84074
P: 435.843.3590
RICHFIELD
225 N 100 E
Richfield, UT 84701
P: 435.896.2983
www.ensigneng.com
Structural Engineering
Municipal Services Civil Engineering Land Surveying
September 11, 2024
J. Paul Wright
Southwest Utah District Engineer
Utah Division of Drinking Water
620 S 400 E, #400
St. George, UT 84770
RE: Foothill WUA Improvements: August 20th Comment Response
System No. 11099; Project No. 11884A
Dear Paul,
We have addressed your comments regarding our most recent submission of the Foothills
Drawings, Technical Specifications, and Water Model data on August 20th, 2024. Please see your
comments below, followed by how each was addressed.
1) Regarding the response to Item No. 2, I am not able to complete a full review of the tank
portion of the plans until the full tank design is designed by a licensed professional engineer
and submitted for review. In other words, since the tank replacement really is the main
element of this project, I cannot prepare a plan approval letter simply based on a specification
listing the requirements to a design subcontractor. The full design will have to be submitted.
There have been other projects over the years that use a subcontractor for the design of a
bolted steel tank, and those design drawings become a part of the submission to DDW for
review and approval.
a) We would like to move forward with the conditional plan approval until the tank design
supplied by the contractor can by approved by the DDW. We understand that no payments
can be made until full plan approval has been received.
2) The hydraulic model for fire flow scenario shows 0 (zero) psi at the required fire flow for nodes
J5-J10. 20 psi is the required minimum pressure for fire flow plus peak day demand, not zero
psi. Is this correct? You should show what fire flow can be obtained at the minimum required
pressure of 20 psi and if it is less than what the fire authority would require, we need
documentation from them that it is still adequate to meet their fire flow requirement.
a) For the hydraulic model we used a fire flow of 2000 gpm to accommodate the Paragonah
Fire Department’s largest capacity truck. After speaking with the Fire Chief (Royce Barton,
435.559.3430) we modified the model to use a fire flow of 1500 gpm at which the minimum
pressure is 17 psi. We also found that the maximum fire flow that can be used to obtain a
minimum pressure of 20 psi is 1,469 gpm. Are these values close enough to be
acceptable? I have attached the reports for Fire Flow generated by the hydraulic model
for both scenarios (20 psi at 1,469 gpm and 17 psi at 1,500 gpm).
3) The temporary tank submission didn’t really show any of their details regarding screens,
venting, hatch type (shoebox lid) etc. We just need to make sure the tank is protected from
potential sanitary defects while it is being used. I realize this will likely be a rental, but we just

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want to protect the water system while construction is taking place and these tanks are being
used. I think this is something we can address as construction starts.
a) We will review designs obtained by the contractor and ensure that all of these details are
included prior to construction.
4) Sheet C500, equipment Item C (flow meter) was not labeled on the proposed well house
design.
a) A label for the flow meter has been added.
5) It appears that the well pumps to the tanks through the distribution system, without having a
separate transmission line? You call out an “air release” valve Item E on Sheet C500, which
refers to detail 3 on Sheet C801, but this is not the correct type of air release/vacuum valve
(described below in the rule citation). The mushroom style air release valve you show is only
for gravity flow situations and is just a screening mechanism that is connected to an actual
air/vac valve. The correct type is similar to the air release valve you show on sheet C800,
detail 15. That being the case, the following applies and should be part of the proposed well
house design: (v) where a well pumps directly into a distribution system, must be equipped with
an air release vacuum relief valve located upstream from the check valve, with exhaust/relief
piping terminating in a down-turned position at least six inches above the well house floor and
covered with a No. 14 mesh corrosion resistant screen. An air release vacuum relief valve is not
required if the specific proposed wellhead valve and piping design includes provisions for
pumping to waste all trapped air before water is introduced into the distribution system;
a) We believe that there is a transmission line between the well and the tank with a separate
distribution line feeding the system from the tank (there are no records of what the piping
actually looks like). We have updated the air/vac valve on Sheet C-500 to show the proper
item and have removed the mushroom style air release valve.
6) The proposed well house should meet the following with regards to drainage. The floor
appears to be recessed below the footings for the proposed well house: (b) Floor Drain.
Where a well house is constructed, the floor surface shall be at least six inches above the final
ground elevation and shall be sloped to provide drainage. A "drain-to-daylight" shall be
provided unless highly impractical.
a) The design of the well house has been updated to show a full concrete slab around the
existing piping with floor drain and the updated drawings have been sent with this letter.
7) You show the well casing extending 12 inches above the well house floor, which appears to
be a recessed floor that they already have. The 12 inches only applies if this is a finished floor
(described in comment 5 above), that already is raised up 6 inches above finished grade. So,
in reality, the casing should be 18 inches above natural grade (12 inches above a finished
well house floor) as shown in the rule below: (a) Casing Projection Above Floor. The
permanent casing for all ground water wells shall project at least 12 inches above the pump
house floor or concrete apron surface and at least 18 inches above the final ground surface.
a) The plans have been updated to clarify that a extension to a minimum of 18-inches above
ground surface will be required.
8) It appears that on Sheet C801, detail 2, that a well casing air vent is planned to be installed.

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Page 3
This detail should be called out also on Sheet C500, on the new well head so that it can be
installed at the time of the well head modification.
a) A callout has been added on Sheet C-500 for a well casing air vent.
If you have any questions concerning the information noted above before proceeding with a full
plan review, please feel free to contact us anytime.
Sincerely,
Rianna Howard, EIT
Fire Flow Node FlexTable: Fire Flow Results Table
Pressure
(Calculated
Residual)
(psi)
Pressure
(Residual Lower
Limit)
(psi)
Flow (Total
Available)
(gpm)
Flow (Total
Needed)
(gpm)
Fire Flow
(Available)
(gpm)
Fire Flow
(Needed)
(gpm)
Label
3401,4731,4721,4691,468J-1
3801,4731,4721,4691,468J-2
4001,4731,4721,4691,468J-3
4001,4741,4731,4691,468J-4
3701,4751,4741,4691,468J-5
4101,4741,4731,4691,468J-6
3901,4701,4691,4691,468J-7
3501,4781,4771,4691,468J-8
3101,4761,4751,4691,468J-9
2001,4821,4811,4691,468J-10
Page 1 of 176 Watertown Road, Suite 2D Thomaston, CT
06787 USA [phone]
9/11/2024
WaterCAD
[10.04.00.108]
Bentley Systems, Inc. Haestad Methods Solution
CenterFWUA Water Model.wtg
Fire Flow Node FlexTable: Fire Flow Results Table
Pressure
(Calculated
Residual)
(psi)
Pressure
(Residual Lower
Limit)
(psi)
Flow (Total
Available)
(gpm)
Flow (Total
Needed)
(gpm)
Fire Flow
(Available)
(gpm)
Fire Flow
(Needed)
(gpm)
Label
3401,5041,5031,5001,499J-1
3701,5041,5031,5001,499J-2
3901,5041,5031,5001,499J-3
4001,5051,5041,5001,499J-4
3601,5061,5051,5001,499J-5
4001,5051,5041,5001,499J-6
3701,5011,5001,5001,499J-7
3301,5091,5081,5001,499J-8
2801,5071,5061,5001,499J-9
1701,5131,5121,5001,499J-10
Page 1 of 176 Watertown Road, Suite 2D Thomaston, CT
06787 USA [phone]
9/11/2024
WaterCAD
[10.04.00.108]
Bentley Systems, Inc. Haestad Methods Solution
CenterFWUA Water Model.wtg

SANDY
45 W 10000 S, STE 500
Sandy, UT 84070
P: 801.255.0529
LAYTON
919 North 400 West
Layton, UT 84041
P: 801.547.1100
CEDAR CITY
88 E Fiddler’s Canyon Rd, STE 210
Cedar City, UT 84721
P: 435.865.1453
TOOELE
169 N. Main St, Unit 1
Tooele, UT 84074
P: 435.843.3590
RICHFIELD
225 N 100 E
Richfield, UT 84701
P: 435.896.2983
www.ensigneng.com
Structural Engineering
Municipal Services Civil Engineering Land Surveying
August 20, 2024
J. Paul Wright
Southwest Utah District Engineer
Utah Division of Drinking Water
620 S 400 E, #400
St. George, UT 84770
RE: Foothill WUA Improvements: August 8th Comment Response
System No. 11099; Project No. 11884A
Dear Paul,
Per your request, we have addressed your comments regarding our previous submission of the
Foothills Drawings, PNF, and Technical Specifications for your review on August 8th, 2024. Please
see your comments below, followed by a description of how each was addressed.
1) Regarding the location, elevation, and hydraulic modeling related to this new tan,. In the
Master Plan that was completed in 2023, the modeling scenarios for Peak Day Demand
(required minimum pressure of 40 psi) and Peak Instantaneous Demand (required minimum
pressure of 30 psi) only showed figures that showed < 40 psi at the tank site and <120 psi at
other points in the system, but didn't really give tabular output of the pressures for those
scenarios. Now that a new tank is being proposed, has this been remodeled based on a new
elevation and if it is similar, can you provide the actual model output table pressures to ensure
this water system meets those requirements?
a) We have re-run the water model with the current proposed tank location and elevation. I
have attached exhibits for Peak Day and Peak Instant scenarios showing all of the results
as well as an exhibit for the fire flow.
2) The drawings do not appear to include a full tank design, just a basic civil layout and a cross
section. For a full tank review, you should review R309-545 attached and ensure all of the
appropriate design details and information are included in the plans, which may entail: Ladder
details (exterior and interior), Safety railings, Hatch details, Slopes for roof and floor for
drainage, air vents, Overflow design, outfall and discharge details and location. Even if this is
going to be a separate contractor, you should review those plans to ensure they fully meet the
requirements of R309-545 and they also need to be submitted to me.
a) We are going to have the contractor for the project be responsible for obtaining the design
for the tank. We have added a callout for the requirements in the drawings and in the
Measurement and Payment. There is also a section in the Specifications for the tank
requirements.
3) The temporary tank needs to also show similar details as described above and it needs to be
certified to be ANSI/NSF61 certified for drinking water.
a) I have attached all documents that we have received for the Rain for Rent temporary water

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Page 2
tank. However, we will provide this as an option for bidders and still allow them to seek
out an alternative if they can find a better one. We have added these requirements
(ANSI/NSF and R309-545) to the Measurement and Payment line item as well as the
drawings.
4) Plans that are submitted for review should be final and ready for bidding/construction which
also means they should be stamped by a Licensed Professional Engineer.
a) Curtis Nielson has stamped the updated drawings and these have been included with the
submission of this letter.
If you have any questions concerning the information noted above before proceeding with a full
plan review, please feel free to contact us anytime.
Sincerely,
Rianna Howard, EIT
[phone]
[e-mail]