Geothermal Switch Lowers System Cost for North Adams School Project
NORTH ADAMS, Mass. — The cost estimates for the Greylock School project are coming in slightly under budget — including the planned geothermal system.
Initial estimates for the alternative heating system came in at $5 million — $3 million over budget.
"We realized this is never going to work at this cost and we needed to think about the system a little differently," said Jesse Saylor of TSKP Studio, the school's designer, told the School Building Committee on Tuesday. "So we reached out to the well designers and came up with an alternative design, which we feel is much more appropriate for your site."
A redesign from using vertical wells to horizontal wells, reduced the costs to $1.5 million.
Saylor explained that the drillers had gone down more than 440 feet, through soil and more than 200 feet of bedrock and hit the aquifer, which had to be capped off because of the pressure.
"So our design heading into the cost estimate was to shorten the depth of the wells. Let's not penetrate into that aquifer. Let's just go down 400 feet," he said. "They wanted to carry steel casing all the way down the 400 feet of depth, because the concern is that aquifer depth may vary across across your site, and so that was driving up the initial cost."
That vertical system would have required 66 wells and cost about $5 million. Instead, the system will now run horizontally at a depth of about 20 to 30 feet.
"We don't get anywhere near the aquifer, and we don't need the bedrock. In this case, we don't have any casing involved," Saylor said. "So this seems like a better fit for our site."
The geothermal system will be out of sight below the parking lot on the south side of the new school.
Mayor Jennifer Macksey, chair of the committee, noted her concerns over using the state-mandated geothermal system from the beginning. She asked why the designers hadn't looked at the less expensive horizontal option in the first place.
"While the technology's not new, it's just having enough vendors in the area," said Saylor. "And we believe we have found three that are interested in the project."
The approved changes are part the design package being submitted to the Massachusetts School Building Authority on Wednesday. The MSBA will review the documents over the next few weeks.
Overall, the estimators have come up with a total $52,738,200, about $600,000 under the budgeted amount of $53,405,500.
This involved two independent estimators and a reconciliation with the design team to make sure they're looking at the documents in the same way and seeing the same quantities of material.
"We're on budget, we're on target," said Tim Alix of owner's project manager Colliers International. "We had to look at maybe doing some things a little bit differently but in the end the number came in with our budget."
The numbers will be reviewed again at the 90 percent design phase.
Alix said $1.6 million in invoices have been approved to date and, of those, about $940,000 are eligible for reimbursement. He anticipated about $750,000 coming back to the district.
"A little bit less than half of what's been spent to date," he said. "This is kind of expected. That percentage goes up and down as we move through the project and different phases. More items or less items are deemed eligible or ineligible for reimbursement."
The district now has signed a funding agreement with the MSBA and can begin entering invoices electronically as they come in. Alex figured about three weeks from submitting bills to receiving reimbursement.
"It's kind of a revolving process," he said. "You're never really spending all of these funds, because you're getting money back on a consistent basis."
The project is now moving into the construction document stage and engineering firm Salas O'Brien, with offices in Albany, N.Y., and Hartford, Conn., has been selected by the MSBA as the commissioning consultant.
Tags: Greylock School Project,
