Ice Rinks with slab foundations consist of two systems. The cold system is the upper level of the two and sits within the poured concrete slab, chilling the floor that produces the ice surface. The second system is the warm system, which rests below and provides warmth in order to prevent permafrost from forming and keeps the soil the system rests on stable. If a warm floor is not operating properly over an extended period of time, permafrost will form, resulting in heaving of the cold slab and damage the cold system.

The Allen Community Ice Rink became aware of slab displacement in early 2015. With maintenance to the chiller package planned in the summer of 2015, the building team decided to pressure test the warm system to identify leaks and status of the under floor lines at that time. The initial attempt to test the underfloor warm system for leaks was halted when the initial air pressure test identified damaged lines from the chiller package to the ice rink not allowing the testing of the lines under the ice slab. In response to this, the team worked with contractors to install an isolation valve next to the community rink to allow testing of the under floor lines. This install and testing was completed in April 2016, with the test identifying that the lines would not hold pressure. Leaks in the system and the brine solutions corrosive traits were determined to be the cause of the failure.

The team reached out to the Chiller Package installer, Cimco, to evaluate options. Cimco's proposed option was complete replacement of the warm system which would require removal of portions of the undamaged cold floor and result in a 3 to 5 month closure of the ice rink with a replacement cost estimated between $700,000 to $900,000. Staff began researching to determine if there were other options for repair or replacement.

Upon heavy research, staff is recommending proposal is to install new warm lines by using directional boring from the exterior of the rink and then install an independent header, pump and heater to create a new independent system. To determine the feasibility, a directional boring test was performed in June 2016 with positive results.  The benefit of this approach is the installation of new lines. An attempt to repair the damaged warm system is not feasible since we are unable to access it since the header and lines are below the cold floor system. With this alternative, there would not be a need to risk removal of a portion of the cold floor system, which currently is operational. The proposed repair is estimated to be approximately 1/2 of the total expense of the complete removal and repair; and provides a repair with minimal impact on ice rink programming and revenue streams.

The recommend repair would be completed by three primary vendors on the project:

1. Trinity Boring Solutions Inc. - directional boring and installation of earthloop poly piping at the Community Ice Rink
2. Polk Mechanical Company - excavation, concrete work, trim, and mechanical and architectural components at the Community Ice Rink
3. Golden State Hockey Rush LLC, - specialized Heat Floor installation and materials

Full Overview and Estimate of the project is as follows:

*denotes contract previously approved by City Council 5/9/2017.

Being expedient on this project is imperative to protect the currently undamaged cold floor system which already had heaving up to three (3) inches in some areas. The Rapid Thaw Project saw displacement reduced to two inches in June 2016 but the full displacement level had returned by Dec 2016.  Inaction would lead to the permanent damage and failure of the ice floor and force a full closure of the ice rink by an estimation of summer of 2017. Repair at that point would be a full ice rink floor system replacement. 

Project funding is available from non-bond CIP funds.  As outlined in the attached letter from TML, a portion of the repair costs will be reimbursed directly to the City as a result of a recent insurance claim.

Staff recommends that the City Council authorize the City Manager to negotiate and execute construction agreements with Trinity Boring Solutions, LLC d/b/a Texas Directional Boring Inc., Golden State Hockey Rush, LLC d/b/a GS Ice Sports, and Polk Mechanical Company for repair of the Community Ice Rink Warm Floor System in a total construction amount $458,763.

I make a motion to authorize the City Manager to negotiate and execute construction agreements with Trinity Boring Solutions, LLC d/b/a Texas Directional Boring Inc., Golden State Hockey Rush, LLC d/b/a GS Ice Sports, and Polk Mechanical Company for repair of the Community Ice Rink Warm Floor System in a total construction amount $458,763.