To: Honorable Mayor and Members of Town Council
From: Mark Marlowe, P.E., Director of Castle Rock Water
Matt Benak, P.E., Water Resources Manager
Heather Justus, P.E., Water Resources Project Manager
Title
Resolution Approving a Construction Contract with Hydro Resources - Rocky Mountain, Inc. for Wells CR-228, CR-229 and CR-230
Body
________________________________________________________________________________
Executive Summary
The purpose of this memorandum is to request Council’s approval of a Resolution (see Attachment A) approving a services agreement with Hydro Resources - Rocky Mountain, Inc. (Hydro) for the construction, including drilling, completion, testing and pumping equipment installation of the Lanterns Well project, which includes the construction of three new Denver Basin wells that will supply water to the Plum Creek Water Purification Facility (PCWPF). The new wells will help to firm the supplies from the existing Denver Basin infrastructure. Leonard Rice Engineers, Inc. was selected for the professional services associated with construction of the three wells at the Lanterns Well Site.
Castle Rock Water staff meet with Hydro in August 2018 to determine if Hydro’s schedule could accommodate drilling three wells starting in October 2018. Through bidding of the replacement wells (15R and 16R) and drilling of CR-227, staff had determined that Hydro’s prices are competitive and communication through both projects was successful despite some construction challenges that were encountered and resolved. Staff recommends approving a construction services agreement based on the qualified proposal from Hydro Resources - Rocky Mountain, Inc. in the amount of $3,537,398. In addition, Castle Rock Water staff requests a 10% Town-managed contingency in the amount of $353,740, for a total authorization of $3,891,138. The Construction Agreement is included as Exhibit 1. Raw water delivery infrastructure design and construction packages will be determined at a later date.
Discussion
Based on the Water Resources Supply Demand Model, the high population growth trend, the last two summer water demand seasons, and aging well infrastructure, additional water supply is needed to keep pace with increased water demands and to firm supplies. The new well infrastructure will help firm and increase current supplies.
The new Lanterns Well Facility will be located south of Crystal Valley Parkway (see Attachment B) on a parcel that is planned to be dedicated to the Town for the purpose of developing a well facility. The project will include the construction of three new Denver Basin Aquifer wells, controls and meter facilities at the site, and a transmission pipeline to convey the water to the Plum Creek Water Purification Facility. Staff anticipates that this facility will produce an estimated range between 1 million gallons per day (MGD) to 1.5 MGD with an average of 1.2 MGD of raw water supply for the Town.
Upon direction from Castle Rock Water leadership that we needed to continue moving forward in firming Denver Basin water supplies, Castle Rock Water staff met with Hydro to determine schedule availability and timing. Based on conversations and previous bidding and the desire to drill the wells during fall/winter months, staff determined that sole sourcing (see Attachment C) the drilling construction contract with Hydro was in the Town’s best interest. Based upon conversations with other water districts along the Front Range Corridor and Hydro, we learned that multiple entities were planning to drill new wells and we did not want to potentially delay the drilling of this project due to the unavailability of the drilling contractor. Hydro has availability to begin construction as early as the end of September but will most likely be able to move onto the site in early October. Also, the other drilling contractor available to complete this work had a dispute with us during a previous project and did not properly communicate with staff or our consultant before critical periods to help resolve construction complications. Staff worked with Leonard Rice Engineers, Inc. to prepare an updated, site specific design for the Lanterns Denver Basin wells. In addition, the well specifications were updated to reflect the changes in design and the lessons learned on previous projects.
The new well design includes using stainless steel casing and maximizing the screen intervals below the static water table and using stainless steel drop pipe in the pumping equipment. Using stainless steel increases the longevity and efficiency of the wells. Over the last few well rehabilitation projects, through the pre-cleaning videos and the condition of the drop pipe, staff has noted increased corrosion on the casing and the drop pipes due to the introduction of oxygen into the wells. According to the book titled Sustainable Wells: Maintenance, Problem Prevention, and Rehabilitation by Stuart Smith and Allen Comesky, “Stainless steels have good corrosion resistance in general, but most especially if oxygen is present.” In addition to reducing the corrosion, the growth of iron bacteria will slow down which help reduce the overall costs of rehabilitation of the wells and will increase the life of the well.
Hydro’s proposal addressed the full scope of work and alternative scope items, and staff believes the proposal amount to be a good value to the Town based on previous similar scopes of services. Staff compared the price sheets provided by Hydro to the actual construction costs for CR-227, CR-226, CR-15R and CR-16R.
ARAPAHOE WELLS
Lanterns Well - Proposed price CR-227 Actual
$1,856,667.33 $1,863,956.33
Difference ($7,289.00)
The Lanterns Arapahoe aquifer well design incorporates potential mitigation designs for the risks of Dawson aquifer caving and lost circulation issues. In addition, the design includes efficient design elements such as glass bead filter pack and maximizing screens and stainless steel below the expected water table depth.
DENVER WELLS
Lanterns Well - Proposed price CR-226 Actual CR-15R
$1,230,448.33 $1,619,720.10 $743,591.00
Difference ($389,271.77) $486,857.33
The Lanterns Denver aquifer well design is a larger diameter well than CR-15R due to the potential of increased well production. Due to CR-15R and CR-16R being replacement wells very little site preparation work was needed to bring the drilling rig onsite. The site must be level in order to drill a straight hole at the depths required. The Lanterns Denver aquifer well design does incorporate the more efficient design elements of glass beads for filter pack and maximizing screen casing and stainless steel casing below the expected water table.
DAWSON WELLS
Lanterns Well - Proposed price CR-16R
$450,282.33 $516,549.00
Difference ($66,266.67)
Both wells are designed as the same size diameter; however, 16R is slightly deeper. The Lanterns well design does incorporate more stainless steel and will need more site preparation.
The construction which includes the drilling, completion, testing and installation of pumping equipment for the wells is planned to start in early October and is expected to continue through March of 2019. The drilling, completion and development activities for the three wells will occur during October through December. The pump testing is planned for January. The pump testing results will help staff and consultants finalize the design of the pumping equipment which will then be ordered. The lead times on the pumping equipment is 8 to 12 weeks out from time of ordering. Once the equipment arrives, it will be installed in the wells. Castle Rock Water engineering staff will begin the preliminary design in the winter and will issue a Request for Proposal for Engineering Services in the winter 2018. The raw water transmission line will need to pass under the Crystal Valley Parkway Bridge (or be hung from the bridge deck), Plum Creek and a railroad crossing before connecting at the end of the Heckendorf pipeline that will transmit the water to Plum Creek Water Purification Facility. A temporary use of the water may be available for summer 2019; however, the final connection to PCWPF is not anticipated until 2020.
The construction services will include the drilling of one Arapahoe aquifer well, one Denver aquifer well and a Dawson Aquifer well. Hydro has provided construction services on the Castlewood Well CR-227 Project and the re-drills for 15R and 16R. Staff is confident of Hydro’s capabilities to complete this project within budget and on schedule, and we recommend the award of the construction contract to Hydro Resources.
Budget Impact
Funding for this project was not planned in the 2018 budget, therefore Castle Rock Water will complete a budget amendment to the account “New Water Supply Well” (Account No. 210-4275-442.75-39). The Town will use these funds for the construction which includes drilling, completion, testing and pumping equipment installation of this project. The Hydro proposal fee is $3,537,398. Staff requests a Town-managed contingency in the amount of $353,740 for a total project authorization of $3,891,138.
Project Amount Contingency Total Account
210-4275-442.75-39 $3,537,398 $353,740 $3,891,138
New Water Supply Well
Staff Recommendation
Staff recommends Council’s approval of the construction agreement between the Town of Castle Rock and Hydro Resources - Rocky Mountain, Inc. for drilling, completion, testing and pumping equipment installation for the construction of the new Lanterns and Ridge Road Wells CR-228, CR-229, and CR-230 in the amount of $3,537,398 plus a 10% Town-managed contingency of $353,740 for a total authorization of $3,891,138.
Proposed Motion
“I move to approve the Resolution as introduced by title.”
Attachments
Attachment A: Resolution
Exhibit 1: Construction contract
Attachment B: Location Map
Attachment C: Sole source