District told ComEd will charge about $117,648 to insulate transmission line for geothermal hookup

Oak Park–River Forest School District 200 officials told the board the district has reached a technical solution with ComEd to cross a 38,000-volt transmission line for the Project 2 geothermal field, but ComEd’s work is estimated to cost $117,648.

Board members were told the cost comes from ComEd’s requirement to insulate the line and to change how the district’s geothermal piping will cross the utility easement; the district’s team said ComEd set the price after performing on-site testing last week. The district’s staff and contractors — including Gilbane and the geothermal consultant (Verigee/Verity in the record) — presented the solution and said the work will not change the project schedule.

The geothermal line-crossing issue emerged during the Project 2 construction discussions. Tony (staff member) summarized that initial designs had assumed the geothermal well field could be routed north of the football field and that crossing the transmission line would likely be similar to Project 1. After additional testing and engagement, ComEd required the line to be insulated and the district to run the geothermal piping under (rather than over) the transmission line, producing the $117,648 estimate. “The thermal activity is really what ComEd is worried about,” Jeff (remote participant) said, explaining that heat around buried lines reduces capacity and is the reason for ComEd’s specifications.

Several board members pressed staff on why the cost was not foreseen earlier. One member asked whether the district or consultant could have requested depth testing from ComEd sooner; staff answered that district teams had believed the earlier depth assumptions were reasonable and that ComEd’s formal depth and insulation requirements could only be determined after ComEd’s on-site testing. Staff said ComEd had been slow to respond initially but assigned a responsive project manager and that the solution is now agreed among ComEd, Gilbane and the district’s contractors.

District staff said the cost will be accounted for within Project 2’s contingency. The board was told the Project 2 contingency currently has about $1,574,000 remaining; staff said the program’s original contingency pool was larger (board members recalled a starting contingency “up toward $1.8 million”) and that the geothermal line-cross cost is being allocated to Project 2 because the work occurs in the Gilbane-managed footprint.

Board members raised two practical concerns: whether deeper placement of the entire well field from the start would have avoided this fee (staff and consultants said making all wells substantially deeper would likely have cost more and introduced performance risk), and whether there were alternatives or competing bids for the ComEd work (staff said ComEd controls testing and its crews and the proposal is not a competitively bid subcontract in the usual sense). Staff and contractors repeatedly described geothermal crossing of a high-voltage transmission line as an uncommon technical issue and said this specific thermal/insulation concern was not fully predictable until ComEd’s involvement.

The board did not take a final vote on approving ComEd’s contract during the discussion; staff said the item will be returned for a formal contract approval consistent with board rules for large contracts. Staff projected the change would not affect the Project 2 schedule.

The conversation concluded with board members emphasizing better early coordination with ComEd and clearer documentation of risk in future geothermal planning, and staff committing to bring the formal contract action back to the board for approval.