Crews work on the Davis Brook Storage Tank project, last August on the Bangor Waterfront. The project has resulted in a new, 3.8 million-gallon underground storage tank to keep sewer system overflow from draining into the Penobscot River. Credit: Courtesy of the City of Bangor

The city of Bangor and the company that produces concerts on the city’s waterfront both found novel ways to use gigantic mounds of dirt dug up during the installation of a new, 3.8 million-gallon storage tank buried under the waterfront — and save more than half a million dollars in the process.

Those uses include the creation of a new public trail for Bangor’s parks system and upgrades to the Maine Savings Amphitheater in time for the 2022 summer concert season.

The Davis Brook CSO Storage Tank project, part of a larger $63 million project that began in February 2020, has resulted in the construction of a multimillion-gallon tank buried under the waterfront that will collect raw sewage and stormwater overflow and prevent it from draining into the Penobscot River. It will be completed in June 2022, just as the 2022 Waterfront Concert season at the Maine Savings Amphitheater, which sits adjacent to the construction site, will begin.

Once it’s done, the waterfront won’t look very different from the way it looked prior to construction, according to Bangor city engineer John Theriault.

“It’ll be the same walking trails everyone was used to before the project began,” Theriault said. “By the fall we expect it to all be green and landscaped again.”

The major difference will be the absence of around 60,000 cubic yards of contaminated fill from the storage tank project, which required the excavation of a gigantic hole on the waterfront. While the city has found a way to use virtually all of it, it was a complicated task.

Among the complications from the project, which the U.S. Environmental Protection Agency required in a 2015 consent decree, is the fact that the waterfront site is considered a “brownfield,” as the area was once a railroad yard. The soil there is contaminated with heavy metals and other chemicals, and thus cannot be removed from the site, unless it is either taken to a landfill — a costly undertaking — or to another brownfield-designated site.

While some of the fill could be deposited at a parcel of city-owned land located behind Hollywood Casino, that space was not nearly sufficient to hold all of it. That’s where Waterfront Concerts and Bangor Parks and Recreation came in.

Waterfront Concerts needed a large amount of fill as part of its upgrades to the Maine Savings Amphitheater, and the company was happy to take some of the city’s nuisance fill to complete their project.

“We’ve increased the elevation of the rear of the venue for sightlines, so we trucked in over 15,000 cubic yards of that material to raise it all up,” said Waterfront Concerts president Alex Gray. “We have pretty incredible sightlines now.”

The city then came up with a novel solution for placing another 15,000 cubic yards of dirty fill: moving it to another brownfields site in town, located on city-owned land on Essex Street, adjacent to the  Essex Woods trail system. That location was a public dump until the 1960s. The city applied for a beneficial use permit from the Maine Department of Environmental Protection so it could bring materials from the waterfront to be buried at the Essex Street site. The city received the permit in 2020.

Last year, the city’s engineering and parks and recreation departments collaborated to use the fill to create a new parking area located at 615 Essex St., and a new trailhead that connects that parking area to the established trail system at Essex Woods, a popular city park formerly only accessible off Watchmaker Street.

The new trail is flat, and allows park-goers to avoid having to climb a very steep hill to return to their cars. The contaminated fill has been buried under a protective layer of geotextile and a foot of clean fill, so there’s no danger of disturbing it.

Assistant parks and recreation director Debbie Gendreau said the trail system extension is not yet complete and still needs signage and other upgrades before it officially opens to the public. She said the new trailhead is beautiful and will be of particular interest to local birders and wildlife watchers, as it offers more viewing areas along the marshlands in the park, where red-winged blackbirds, kingfishers, herons, egrets, painted turtles and beavers can be spotted.

“If you love seeing the birds and turtles along the marsh area, it’s going to be something you’re really going to enjoy,” she said.

S.E. MacMillan Co., the construction firm contracted to do the Davis Brook project, struck a deal with the city that if all the fill could either be moved to the waterfront site, to be used by Waterfront Concerts, or taken out to Essex Street, the company would credit the city with $650,000. Minus the estimated $100,000 it cost to get the permit from the Maine DEP and to move the fill, the city ended up saving around $550,000.

“We saved half a million dollars, and also created a benefit for the city,” Theriault said. “It more than paid for itself.”

Correction: An earlier version of this article misstated the cost of the storage tank project. It was a component of a larger $63 million project

Emily Burnham

Emily Burnham is a Maine native and proud Bangorian, covering business, the arts, restaurants and the culture and history of the Bangor region.