To: Honorable Mayor and Members of Town Council
Through: David L. Corliss, Town Manager
From: Mark Marlowe, P.E., Director of Castle Rock Water
Matt Benak, P.E., Water Resources Manager
Title
Resolution Approving an Intergovernmental Agreement Between the Town of Castle Rock, the South Metro Wise Authority, Dominion Water and Sanitation District, and Parker Water and Sanitation District Regarding the Wise Pump Station and Infrastructure Design [Location: Rueter-Hess Reservoir, Parker Water and Sanitation District, Parker, CO]
Body
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Executive Summary
The purpose of this resolution (see Attachment A) is to seek Town Council approval of a cost-sharing intergovernmental agreement with Parker Water and Sanitation District (PWSD) for the design of an expansion to PWSD’s WISE pump station and associated infrastructure. The approximate location of the future pump station is provided in Attachment B.
One of Castle Rock’s key pieces of its renewable water supply portfolio is water from the Water Infrastructure and Supply Efficiency (WISE) project. The WISE Program is a source of renewable and sustainable water supply for 10 South Metro water providers, including Castle Rock and PWSD. In 2015, a 42-inch steel pipeline, the RidgeGate Line (RGL), was designed and constructed to convey WISE water from the primary WISE East-West transmission main to RGL regional partners. At that time, the associated WISE receiving tank, pump station, and site piping were deferred, and the pump station inside PWSD’s existing Rueter-Hess Water Purification Facility (RHWPF) was used to pump WISE water.
Now, PWSD is in need of its own pump station capacity within the RHWPF and desires to design and construct the deferred WISE infrastructure. It is PWSD’s preference that the design be completed to allow for construction to begin no later than January 2023. As such, PWSD issued a Request for Proposals (RFP) to qualified engineering firms in September 2021. Seven proposals were received ranging in fees from $499,602 to $1,355,390 (average fee of $877,513). HDR was selected as the top respondent with a design fee of $825,600 (Castle Rock’s portion of the design will be $401,372.32.)
Notification and Outreach Efforts
This is a design project located at Rueter-Hess Reservoir, so no specific notification or outreach efforts are anticipated.
History of Past Town Council, Boards & Commissions, or Other Discussions
See Attachment C for this information.
Discussion
In September 2021, PWSD requested proposals from consulting engineering firms (Consultants) to provide design services for necessary WISE infrastructure consisting of a receiving tank, pump station, chemical feed systems, and site piping.
In 2015, a 42-inch steel pipeline (the RGL) was designed and constructed to convey WISE water from the primary WISE East-West transmission main to RGL regional partners. At that time, the associated WISE receiving tank, pump station, and site piping were deferred, and the pump station inside PWSD’s existing RHWPF was used to pump WISE water. Now, PWSD is in need of its own pump station capacity within the RHWPF and desires to design and construct the deferred WISE infrastructure. It is PWSD’s desire that the design be completed to allow for construction to begin no later than January 2023.
The South Metro region has historically been reliant on groundwater for its water supply resources. With the WISE system coming online in 2018, a renewable and sustainable water resource is now available to WISE project partners. The WISE system conveys flows via the East-West 54-inch pipeline along E-470 to partners’ individual turnouts and to the 42-inch RGL. The RGL conveys water to the flow control vault located at PWSD’s 10 million-gallon-per-day (MGD) RHWPF site, where it is introduced into the clearwell for mixing and pumped to Zone 2 of PWSD’s distribution system. RGL project partners of PWSD (Castle Rock Water (CRW), Dominion Water and Sanitation District (DWSD), Stonegate, and Pinery) accept their WISE water deliveries via interconnects from the District’s distribution system.
The infrastructure design services requested in this proposal were previously deferred due to the WISE ramp-up period from 2018-2024. During the ramp-up, individual member flowrates gradually escalate to their ultimate peak allocations available in June 2025, pending hydrologic conditions. Since 2018, the fully contracted WISE water deliveries were unavailable, and the RHWPF pump station was able to meet demands of both PWSD customers and WISE project partners. However, with full WISE deliveries coming online and increasing customer demands within PWSD, it is desired that this WISE infrastructure be operational no later than June 2024.
At the time of the RGL design, a hydraulic analysis and surge evaluation was completed to ensure delivery of flows from the RGL connection at E-470 to RHWPF. To validate the hydraulic conditions for this design and eventual operations of the receiving tank and pump station, and any unforeseen ancillary components necessary, a new hydraulic and surge evaluation will be part of the Consultant’s scope of services.
The WISE system is controlled independently of the PWSD system and, therefore, requires its own supervisory control and data acquisition (SCADA) and controls integration to communicate to the WISE backbone SCADA system. Depending on the configuration and hydraulics of the WISE pump station to the PWSD system, additional communication and coordination will be necessary between the two agencies to deliver adequate integration and controls.
PWSD is the operator of the WISE system and will own this infrastructure, but coordination with the South Metro WISE Authority (SMWA) on this project may be required. The Consultant may also be asked to assist in providing updates to the SMWA Board.
The project will be located on PWSD property of the RHWPF. The exact location of the pump station will be determined during the design phase and must accommodate future expansions of the RHWPF.
The following major tasks have been identified as part of the design project:
1. A hydraulic evaluation to confirm project sizing and surge analysis. Pumping capacity of the pump station is based on the ability to deliver peak WISE flows to project partners. Based on the results of the evaluation, a phased approach to the project may be desired due to budgetary constraints or future flow needs (for instance, Castle Rock’s Box Elder Project flows).
2. Design of a pump station to house pump equipment and controls, along with a receiving tank, chemical facilities, and equipment for adjustment of the chloramine residual in the water. An assessment of the advantages and disadvantages of the chemical storage facilities, location, and feeds systems shall be included. The operational flexibility to bypass water within the pump station and an interconnection to RHWPF will also be included.
3. Permanent backup generator power to feed the WISE pump station and ancillary equipment upon local power failure, including standby pumping units. This evaluation will also consider a phased approach for installation.
4. An evaluation of alternative delivery options. This project is currently contemplated as a traditional design-bid-build with a target online date of June 2024; however, an accelerated schedule is of interest to reduce risk of the inability to pump peak WISE deliveries. The Consultant will evaluate and present advantages and disadvantages of potential alternative delivery approaches, specifically schedule and cost implications.
Pumping capacity of the pump station is based on the maximum partnership delivery requirements as listed in Table 1. The cost of the design will be divided among the participants based on the capacity required by each entity to be pumped from the RidgeGate Line via the WISE Pump Station. A total contingency of $60,000 is being included on top of HDR’s contract amount to cover potential work later in the design phase for Construction Manager at Risk (CMAR) services, which might include early work package coordination with the future general contractor that will construct the improvements.
Table 1: Peak WISE Deliveries through the RGL
|
Partner |
Current Allocation [MGD] |
Total Capacity Need [MGD] |
Current Pumping Capacity (Ownership of 7.5 MGD) |
Additional Pumping Capacity Needed [MGD] |
Pro-Rata Share for additional pumping needed |
Cost Share [No Contingency] |
Cost Share [Using CMAR Contingency] |
|
CRW |
4 |
9 |
1.49 |
7.5 |
54% |
$444,793.11 |
$477,118.19 |
|
DWSD |
4.2 |
4.2 |
1.98 |
2.2 |
16% |
$131,527.23 |
$141,085.90 |
|
PWSD |
4.7 |
6 |
1.79 |
4.2 |
30% |
$249,279.66 |
$267,395.91 |
|
Pinery |
0.5 |
0.5 |
0.75 |
0.0 |
0% |
$ - - - |
$ - - - |
|
Stonegate |
3 |
0 |
1.49 |
0.0 |
0% |
$ - - - |
$ - - - |
|
Total |
16.4 |
19.7 |
7.5 |
15.4 |
100% |
$825,600.00 |
$885,600.00 |
Budget Impact
HDR’s cost of the design project, along with the CMAR contingency, is $885,600. CRW has a 54% pro-rata share of this fee for a total needed authorization of $477,118.19.
Monies for this project will come from 211-4375-443.77-72 Water Resources, CIP - WISE Infrastructure, Project Code <WR WLI>. This account has a remaining budget of $2,010,286 for 2021.
Staff Recommendation
Staff and CRW Commission recommend that Town Council approve the Resolution as presented in Attachment A.
Proposed Motion
“I move to approve the Resolution as introduced by title.”
Alternative Motions
“I move to approve the resolution as introduced by title, with the following conditions: (list conditions).
“I move to continue this item to the Town Council meeting on _____ date to allow additional time to (list information needed).”
Attachments
Attachment A: Resolution
Exhibit 1: Agreement
Attachment B: Project Location Map
Attachment C: History of Past Town Council, Boards & Commissions, or Other Discussions