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File #: RES 2019-110    Version: 1 Name:
Type: Resolution Status: Passed
File created: 9/17/2019 In control: Town Council
On agenda: 10/15/2019 Final action: 10/15/2019
Title: Resolution Approving a Construction Contract with Global Underground, Inc. for the Heckendorf Raw Waterline
Attachments: 1. Attachment A: Resolution, 2. Exhibit 1: Contract, 3. Attachment B: Map, 4. Attachment C: Sole Source, 5. Presentation

To:                     Honorable Mayor and Members of Town Council

 

From:                     Mark Marlowe, P. E., Director of Castle Rock Water

 

Title

Resolution Approving a Construction Contract with Global Underground, Inc. for the Heckendorf Raw Waterline

Body

________________________________________________________________________________

 

Executive Summary

 

The purpose of this memorandum is to request Town Council’s approval of a Resolution (Attachment A) for a construction contract with Global Underground, Inc. (Global) for the construction of a new raw water transmission pipeline along East Plum Creek to replace a section of pipeline that is exposed in the creek.  The existing raw water transmission main conveys water from the Heckendorf Alluvial Wells and the new Lanterns Wells to the Plum Creek Water Purification Facility (PCWPF).  The exposed pipe was discovered in 2017, during a stream stabilization project. Staff recommends sole sourcing Global for this work and approving a construction contract with Global in the amount of $627,890.  In addition, Castle Rock Water staff requests a ten percent Town-managed contingency in the amount of $62,789, for a total authorization of $690,679.  The construction contract is included as (Exhibit 1) to the Resolution.

 

Discussion

 

The existing Heckendorf raw water transmission main is used to convey water from the Heckendorf Alluvial Wells and the new Lanterns Wells to PCWPF.  The existing main was constructed in the mid-nineties along East Plum Creek.  A project location map has been provided (Attachment B).  During the 2015 floods, the creek shifted to the west along the pipeline alignment.  The new alignment has exposed a section of the raw waterline within the creek.  The exposed pipeline was discovered in 2017 during a bank stabilization project to protect an existing sewer interceptor that is located in the same area.  The exposed pipeline is vulnerable to damage during another flooding event in the future.  Damage to this pipeline would remove approximately 1.8 Million Gallons per day (MGD) of the Town’s approximate 20 MGD of supply. This is a critical source of supply for meeting peak demand and needs to be addressed before the peak season in 2020.  

 

The design of the new raw water transmission main shifts its alignment to the east.  This new alignment avoids crossing the active channel.  The new pipeline will be installed by Horizontal Directional Drilling (HDD).  This method was determined to be the best construction method for several reasons.  The raw water transmission main is located within Town-owned open space along East Plum Creek.  This area is identified as endangered species habitat and is located within the Town's Habitat Conservation Plan (HCP).  The HDD construction method will minimize the surface disturbances within the HCP.  The terrain also presents some additional challenges for an open cut installation.  The alignment will cross some steep slopes that would require a deep installation.  HDD allows the pipe to be installed at the proper depth without deep excavations.  Finally, the East Plum Creek Trail was completed in this area.  HDD will allow the pipe to be installed without impacting the new trail.  An open-cut installation would require a trail closure while the pipe was installed across the trail.   

 

This memorandum is to request approval of a construction contract with Global for the Heckendorf Raw Waterline Project.  The pipeline has some challenges associated with the installation.  The pipeline will be constructed with fusible 12-inch PVC pipe.  The HDD installation will include vertical and horizontal bends along the alignment.  HDD was identified as the best installation method to minimize disturbance within the HCP.  Global is the only contractor in Colorado that is authorized to fuse the PVC pipe which is required for the HDD installation method.  Global is also the only Colorado contractor that has the equipment large enough to be able to pull the 12-inch pipe for this project.  A Sole Source Justification form has been provided (Attachment C).

 

 

Budget Impact

 

Funds for this project are available in the 2019 budget as shown below. Global’s bid is $627,890. The unit cost for this project is $280 per foot, which is a reasonable unit cost for this type of work.  Global recently completed the Lanterns raw waterline that included a 10-inch HDPE HDD pipe installation.  The unit cost for the Lanterns pipeline project was $286 per foot.  The additional cost associated with the Lanterns project was related to the required steel casing pipe under the railroad.  Staff requests a Town-managed contingency in the amount of $62,789, for a total project authorization of $690,679.

 

Project & Account Code                                          Amount                     Contingency                     Total

 

Repair & Maintenance Equip., Water                     $306,106                     $31,394                      $337,500

210-4275-442.40-32

 

Repair & Maintenance Equip., WR                     $14,332                     n/a                     $14,332

211-4375-443.40-32

 

Pipeline South to Purification                     $307,452                     $31,395                     $338,847

211-4375-443.76-67

 

                     Total                                                                    $627,890                                          $62,789                     $690,679

 

Staff Recommendation

 

Staff recommends Council’s approval of the resolution approving a construction agreement between the Town of Castle Rock and Global Underground, Inc. for construction of the raw water transmission main in the amount of $627,890, plus a ten percent Town-managed contingency of $62,789, for a total authorization of $690,679. 

 

 

Proposed Motion

 

“I move to approve the Resolution as introduced by title.”

 

Attachments

 

Attachment A:                     Resolution

Exhibit 1:                                          Contract

Attachment B:                     Map

Attachment C:                     Sole Source