10 miles of trenches: Oberlin College geothermal project gets underway

OBERLIN — A huge trench has been clawed into the ground behind Finney Chapel, one of the first signs of progress in Oberlin College's $140 million geothermal conversion project. The channel measures about 10 feet wide and 8 feet deep, and follows the edge of Wilder Bowl in the heart of campus. In the coming months, expect more like it to appear. Nearly 10 linear miles will be dug up to remove old, disintegrating pipes and lay new ones, said Meghan Riesterer, the college's assistant vice president of campus energy and sustainability. "In some places it will be a little shallower. This is one of the deeper ones," she said Thursday, peering over the lip of the long furrow near Finney. Oberlin College's steam heat system dates back to 1913, and in recent years has suffered increasing ruptures. Facing the immense cost of repairs, the college decided a full replacement would be the best route — and also move the campus closer to its goal of becoming carbon neutral by 2025. Riesterer's background is in district energy systems, and she has experience from prior jobs in large distribution projects involving steam pipes. She walked the campus Thursday, talking about how the project took seven years to conceive and plan, and how it will come together over the next four years. Riesterer also answered a number of questions already being raised by the curious public. One of the biggest involves the removal of 97 trees, which has caused some alarm in the environmentally minded city. The 440-acre campus is heavily treed, and Riesterer said there is a strategy behind those being removed. "When you start digging in the ground for utility lines or otherwise, you compromise the root structures of the trees," she said. "So they could die in a year (or) five years from now. We can't run the risk of a tree falling on a student or pedestrian." Some healthy trees and bushes have been relocated. A new tree is being planted for every college-owned one removed. Some city-owned trees are also coming down under the oversight of the Public Works Department. Two will be planted to replace each one removed. Riesterer said Oberlin College's arborist was involved in deciding which trees must go and which should stay. Large trees that couldn't be avoided will dry for a year after being taken down before being used to build on-campus furniture. "We took extraordinary measures," Riesterer said. "This is rooted in the Sustainability Office, so we don't take it lightly." During the modernization project's first phase — scheduled for completion before the fall semester begins in early October — most work will occur close to the college's central steam plant. That facility will continue to be used for the next three years as the conversion is slowly done, with both steam and hot water pumping to Oberlin College's 80 buildings until the final switch-over is ready. Each of those buildings must be retrofitted to receive hot water. Workers aren't tackling just one dorm at a time — each will take 30 to 90 days, depending on how geothermal-ready they already are, so crews have to spread out and convert many buildings at once. Riesterer said that while trenches are laid bare, it's efficient to overhaul the college's electric system, fiber optic network and expand the chilled water system too. Already, workers are discovering abandoned steam pipes that had been "lost," she said. Each time, an environmental firm is tapped to abate the pipes. The plan is to remove all of the existing steam pipes completely. With about 108 years of infrastructure buried, workers have been pulling lines made of clay, steel and other materials from the earth, Riesterer said: "Any material you can think of in terms of piping, you can find it on this campus." Eventually, crews will have to dig up steam pipes that cross public roads. That will mean temporary closures. Oberlin residents can sign up for closure alerts and other project updates at carbonneutral.oberlin.edu. About 1,100 geothermal wells will be dug in a much later phase on the north side of campus, at the Yeomen and Yeowomen practice fields. They will draw water from about 600 feet underground. At that depth, the temperature is an even 55 degrees year round, said Riesterer. Geothermal systems use that steady temperature to move water through heat exchangers and warm facilities in the winter and cool them in the summer. When the wells are complete, the land will be returned to practice fields. "That's the big takeaway here," said Riesterer. "When we're all finished, the campus will be restored. It will look just like it did before." The college said the change-over to geothermal will cut its water use by more than 5 million gallons each year, improve energy efficiency by more than 30 percent and reduce annual sewer discharge by more than 4 million gallons. Contact Jason Hawk at (440) 329-7122 or news@lcnewspapers.com.