To: Honorable Mayor and Members of Town Council
Through: David L. Corliss, Town Manager
From: Mark Marlowe, P.E., Director of Castle Rock Water
Roy Gallea, P.E., Engineering Manager
Matthew Hayes, CIP Project Manager
Title
Resolution Approving a Construction Contract with Reynolds Construction, LLC, for the Tank 18 Blue Zone Transmission Project [Pleasant View Drive]
Body
________________________________________________________________________________
Executive Summary
Castle Rock Water is seeking Town Council approval of a resolution (Attachment A) approving a construction contract (Exhibit 1) in the amount of $4,081,473 with Reynolds Construction, LLC (Reynolds) along with $ 408,147 (10%) staff-managed contingency, for a total authorization of $ 4,489,620 to complete construction of the Tank 18 Blue Zone Transmission Project.
The Tank 18 Blue Zone Transmission Project is located along Pleasant View Drive between the Cobblestone Ranch and Terrain subdivisions (Attachment B). This project will provide a direct fill line into the tank from the water main currently feeding water to Cobblestone Ranch and will serve as the main source of water to the subdivision. This main will provide water turnover in Tank 18, which will help to maintain water quality in the tank.
Notification and Outreach Efforts
Preliminary project information is currently published on the Town’s website and will be updated periodically throughout construction. Project information letters were mailed to adjacent neighborhood residents in unincorporated Douglas County in December 2021. Staff have corresponded directly with some residents of unincorporated Douglas County regarding project inquiries.
The new water main is located within Douglas County Right of Way. The project was reviewed by the County as part of their Location and Extent (L&E) process. Part of that process includes notifying adjacent property owners about the project and allowing them to comment on the project.
History of Past Town Council, Boards & Commissions, or Other Discussions
On December 1, 2021 Castle Rock Water Commission was briefed on Water Tank 18 history and anticipated schedule for rebidding construction.
On February 23, 2022 Castle Rock Water Commission voted unanimously to recommend award of a construction contract in the amount of $4,386,765 with DN Tanks along with authorization of $438,700 in staff-managed contingency to complete construction of Cobblestone Ranch 2 MG Water Storage Tank 18.
On March 15, 2022 Castle Rock Town Council voted unanimously to approve a construction contract in the amount of $4,386,765 with DN Tanks along with authorization of $438,700 in staff-managed contingency to complete construction of Cobblestone Ranch 2 MG Water Storage Tank 18.
On April 4, 2022 Douglas County Planning Commission voted unanimously to approve the Location and Extent application for the Tank 18 Blue Zone Transmission Project.
Castle Rock Water staff presented this item to the Castle Rock Water Commission at their meeting held on July 27, 2022, and the Castle Rock Water Commission voted 6 to 0 to recommend Town Council approve the Resolution as presented.
Discussion
The Cobblestone Ranch Development on the far northeastern edge of Town is zoned for 1,245 single-family equivalents (SFEs). In accordance with the Development Agreement (DA), the Town, “in order to fully integrate the water system constructed by the Owner with the Town’s municipal water system,” intended to construct a storage tank and related infrastructure to serve the property at full buildout. The tank project was to be financed and constructed by the Town by reliance on the Owner to purchase water system development fees. The DA further stipulated that should the Town determine that equivalent water services may be provided in lieu of development of the Water Tank the Town could apply revenues received to construct such alternate infrastructure.
Water system development fees are currently $5,700 per SFE. The development is rapidly approaching construction build-out of the 1,245 zoned SFE’s which means water system tap fees collected have fully funded the new tank. The area is currently served by a single 16-inch pipeline from the Castle Oaks area (See Attachment B), with stored water from two existing red zone tanks. The water is fed down into the area through a series of pressure-reducing valves (PRVs) that reduce the red zone supply pressure down to blue zone pressure and then to yellow zone pressure to service the area. The two red zone tanks have a combined operational storage volume of 5.1 million gallons and have sufficient existing storage capacity to meet the operational storage needs of Cobblestone Ranch. However, the storage from these tanks is delivered to the development by a single 16-inch pipeline. The single feed connection through multiple pressure zones is the primary reason a storage tank is needed.
In 2007, one of the PRVs serving the area failed and the resultant high pressure caused a rupture in the pipeline. This resulted in a temporary loss of water service for the entire development. Subsequently, Castle Rock Water installed pressure relief devices on the PRVs so that in the case of a high-pressure event, the PRVs would divert water to relieve downstream pressure. Staff also completed an emergency interconnect waterline to the Pinery Water and Wastewater District system. This provided an immediate interim solution for a second source of water in an emergency.
The long-term solution to a secondary supply of water is a storage tank serving the development. An advantage of a storage tank in the area is that the tank can act as a “damper" in high-pressure events to mitigate pipeline rupture risks and provide an immediate supply for fire protection. Shortly after the high-pressure pipeline event, staff started planning the Tank 18 project.
The Tank 18 Blue Zone Transmission pipeline was identified in the Water Master Plan 2017 Update. This project will supply blue zone water up to the new Tank 18, which is a yellow zone tank. The flow of water into the tank will be controlled with an automated altitude valve. This will allow the flow of water through the tank, minimizing the water age within the tank. One of the Colorado Department of Public Health and Environment's questions about the tank project was how the Town planned on minimizing the water age in the tank.
As of 2022, a significant portion of Cobblestone Ranch has been built out which has increased water demand from the area. Sufficient funding has been collected from tap fees and redundant supply from the tank is now needed to mitigate risk from the single waterline serving the development. The Tank 18 Blue Zone Transmission Project was designed by CR Water staff. The invitation to bid documents were sent to seven qualified contractors. Contractors are pre-qualified for projects annually through a request for qualifications that are advertised on BidNet. Bids were received from two contractors, as summarized in the table below. The Engineer’s estimate was $2,900,000. The low bid was received from Reynolds and is considered a responsive bid.
|
Company |
Bid |
|
Reynolds |
$4,081,473 |
|
ESI |
$4,383,830 |
|
Global |
No Bid |
|
Redline |
No Bid |
|
53 Corp. |
No Bid |
|
Garney |
No Bid |
Budget Impact
Funding for this project will come from the 2022 budget as shown below.
|
Project |
Account Number |
Budget |
Available Balance |
This Authorization |
|
Liberty Village Yellow Zn |
210-4275-442.75-89 |
$ |
$ |
$ |
The Liberty Village Yellow Zone Account has $949,847 available in the budget. The current budget shortfall of $3,539,773 will be allocated by third quarter budget amendment to cover this allocation.
Staff Recommendation
Staff requests Council approval of a construction contract in the amount of $ 4,081,473 with Reynolds Construction, LLC, along with a contingency of $ 408,147 resulting in a total project authorization of $ 4,489,620 for the Tank 18 Blue Zone Transmission Project.
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: Contract
Attachment B: Site Location Map