Forrester Heights Final Reveiw Letter 121007sz3~ ~~~. ~e~~rac~
z~~. aox a~~
~~i~~ra~zt, ~~~sx~i z~~'t~~a ~~~~-z5~s
r. 3.53 w 863.5228 F. 253 a 863 0 09~d6
~a~cazw.paraanetrix.e San
December 14, 2007
PMX No. 247-1751-024
Mr. Jim Gibson, P.E.
Citv of Yelm
105 Yehn Avenue West
Yelm, WA 95597
Re: Forrester Heights Water Booster Puznp Station, Second Review Comments
Dear Mr. Gibson:
On November 21, 2007, we provided comments and reconrmendatiozzs based on review of the design. submittal by
KPFF for the Forrester Heights Booster Pump Station received in our office November 5, 2007. The submittal
included a revised Water Booster Puznp Station dated October 22, 2007 {Engineer's Seal Date), frill. size design
drawings dated October 22, 2007 (Engineer's Seal Datej, and a Washington State Department of Health Project
Approval Application Form (undated). After zneeti.zlg with City of ~elzn staff on December 4, 2007, we are
providing the following comments, which incorporate our previous revie~r as well as City staff comments to be
addressed prior to approval of the booster station plans:
1. Design the system to provide domestic service at the ~0 psi nominal average residual pressure generally
available throughout tlae City of Yelm during peak hourly demand. conditions. Fire service shall meet the
20 psi residual required by DOH.
2. The plans indicate that the booster station wi11 be located in a utility easement. The City requires fee
ownership of the booster station. site. Tlae parcel size shall extend, at a min.irnum, to the fence line as
described in this letter.
3. Revise the building and/or piping layout to allow adequate operator access to the pump skid, service
panel, and. control panel. In the current configuration, an operatoz- would have to step over above-slab
piping, including a pressure release valve and hose bib, to access the panels. Provide a minimum of 2 feet
of clearance on all sides of the pump skid. Please note that some of the carnzlzents and recommendations
in this letter will change the dimensions of the proposed equipment.
4. Provide a b-foot chain link fence aromzd the entire booster station. Locate the fence a minimum of 5 feet
from the brulding footprint and generator pad. Provide a l2-foot double-leaf gate centered on the
driveway at the front of the building and a 3-foot man. gate at the back.
5. Sheet 01.1.0 shows 6-inch piping connecting to the 8-inch pzznap skid manifold. Provide inlet and outlet
piping to match the manifold. The only pipe size transitions shall be at the connections to the existing
I O-inch water main shzbs.
Mr. Tim Gibson
Deeeznber l0, 2007
Page 2
6, Revise the line types used for the in-building piping an Sheet C1l.l. Drawings show dashed lines for
above-slab piping and the pressure tank.
7. Provide flanged camiections on all above-slab piping in the building. Provide rneehar>ieal joint flttulgs
with thrust blocks and megalugs far all below-ground piping. Specifically indicate the fztting and joint
restraint types in the Equipment List on Sheet Cll.O.
~. Provide a check valve on the discharge side of each. prong. `Tire appropriate type of check valve should be
determined. based on the water hannner analysis noted below.
9. Pravide a ball valve curb stop at the tee far the hose bib.
l0. Provide a hose rack on the gall in the vicinity of the hose bib.
l I. Slope the floor slab of the booster station building such that all areas will drain toward the doors.
l2. Provide a lifting strategy for removal of large equipment such. as the pumps and bladder tank.
13. Provide an air gap for the drain line from the pressure relief valve per DOH standards.
1.4. The plans and project report indicate a 35 kW generator will be provided, while the equipment
specifications indicate 40 kW. Qnce all comments that could impact power requirements have been
addressed, provide load calculations to size the generator.
1.5. Draw the generator to scale in the plan view, including the enclosure. Pravide a minimum of 3 feet of
clearance from the building to allow maintenance. and fueling of the generator. Provide a detail of the
generator mounting slab.
16. Pravide the optional foam and sound scoop noise attenuation options on the generator.
I7. Provide HVAC calculations to verify the exhaust fan. and heater selection. Verify that the
24-inch-diameter gable vents will allow adequate aiB°flow to enter the building.
l~. Provide calculations (not estimates) of the fitting lasses and head losses through the boaster station to
verify pump selection is correct Include the losses through the check valves requested in this letter.
19. Perform a water hammer analysis on the booster station and proposed Forrester Heights water distribution
system. The analysis should specifrcally address fire hydrant and system valve operation, narznal pump
starts and stags, anal pump stops due to power outage.
20. Provide bladder tank sizing calculations. Provide two smaller bladder tanks for redundancy.
2l. As previously requested, provide a detailed control grad instrumentation plan and control logic. Describe
the specific instrumentation and cont~~al components proposed for use in the system. Pravide variable
frequency dz-ives (VFDs) far all pumps. In the control logic., include the capability to periodically
alternate which pump serves as lead for providing domestic flows.
22. The plans indicate that the electrical systems will be laidder-designed. Rs previously noted, a detailed
electrical design must be provided to review adequacy of the system prior to approval of this project.
Mr. Jim. Gibson
December I0, 2007
Page 3
23, The electz°ieal system will require review once the mechanical continents have been addressed. General
electrical corments are:
+ Clarify the type of enclosures to be used for the control panel. and transfer switch.
• Provide a minimum of 3 feet of clearance i~a front of the contz°ol panel and transfer switch.
+ Provide weatherproof receptacles inside the booster station.
24. The developer shall provide the equipment necessary to facilitate connection of the booster station to tl~e
City's SCADA system. Specifically, provide a new Remote Terniinal Unit ~RTU) built by Taurus
Controls based on a Rockwell Micrologix 1504 similar to the Water System Well House unit. Frovide an
InputfOutput (IfO) list far the control of new booster pumps, monitoring of the pressure instrumett,
monitoring of the emergency generator, and an intz°usion door switch to Taurus Controls to allow the
system to lie customized to tlkis~ ^~-ci#i~ upp',i~atio.l. I~Iote that this proje:,t wil3 require coordination
between the electrical design and Taurus Controls including instruments, baoster pump controls, and
other features. The IlO list provides a major part of this coordination link. A Parametrix technician will.
verify that the City's radio SCADA system has coverage at the booster station site.
25. The maintenance chart izaeluded in the project report includes references to a well, well house, and
reservoir. Provide aproject-specific maintenance chart.
26. The City will require a double check valve backflow assembly (DCVA) on each water sezviee served by
the booster station to prevent draining of residential plumbing in the event of a water main break.
27. Provide all DOH comments provided in response to tl3e Project Approval Application Fonn with the next
submittal package.
28. Installation of a meter on the discharge side of the booster station was considered, but was determined to
be um~ecessary due to the small area and limited z~zumber of residences served by the station. However,
the City will generally require a meter installed in accordance with City Standards on future water booster
stations.
Once these continents have been addressed and the additional infoz-matiozi requested has been provided, we can
complete our review of the proposed booster station-
If we can be of further assistance, please let us know. Thank you for the
fiery tt-zzly yours,
P RAM TRIX
~~
~.
Ran Y R yzand
Senior Engineer
RR:nkd
P.E.
Municipal Services Group
ik~ichael T. Ollivant, P:E: ~~
Water Solutions Program Manager
you.
cc: Project File