One of the largest single-building projects at the former Fort Devens in central Massachusetts has unusually strict rules requiring numerous erosion controls and balanced cut and fill earthmoving. It also prohibits exporting any soil from the construction site.

McCarty Associates Inc. of Leominster, Massachusetts, is the design-build contractor for the 13-acre project, Mack Devens Development 11, which calls for the construction of a 232,320-square-foot pre-engineered industrial building to house an FDA-licensed pharmaceutical distribution facility. Package Steel Systems Inc. (PSS) of Sutton, Massachusetts, is providing the pre-engineered building components under subcontract to McCarty.

PSS works with erectors and contractors across New England. The company designs and manufactures buildings in-house and ships components to job sites on their own trailers, with shipping and freight costs included in building quotes. The building package typically comes with an anchor bolt plan with dimensions and reactions as well as stamped building drawings for the structural system.

George Aubin, a Consultant for PSS, said a pre-engineered building has advantages over conventional building projects. Most notably, the owner deals with one person rather than several different engineers and trades professionals. He noted that the Devens project is one of PSS’ larger single building projects.

“This building package calls for about 1.6 million pounds of steel,” he said.

The owner of the Devens project is Mack Devens Development 11, LLC, a real estate holding company of McCarty's long-time client, SMC, Ltd. The site was purchased from MassDevelopment. As the state’s finance agency and land bank, MassDevelopment works with businesses, nonprofits, banks, and communities to stimulate economic growth at Devens and elsewhere throughout the state. The agency purchased the Devens property shortly after the U.S. Army base closed in 1996 and is helping with the conversion of approximately 4,400 acres into a non-military-use area under the Devens Reuse Plan.

In line with this effort, McCarty’s contract includes not only the pre-engineered warehouse, but also site improvements, parking, stormwater management, landscaping, and utility infrastructure. The large site is a previously developed parcel that now requires the demolition of existing infrastructure such as water and drainage lines, hydrants, stone retaining walls, and miscellaneous structures.

McCarty must also excavate and replace a large amount of historic fill while abiding by stringent rules. According to the Devens Soil Management Policy, since Devens is a former active military installation, no soil can leave any of its development sites. Furthermore, construction sites at Devens must be balanced, that is, engineered such that all soil remain on the site.

If excess soil needs to be removed from a development site, the material may be transported to another suitable location within Devens, provided the soil is restricted for use only at a commercial site. And before this happens, the material must undergo chemical testing in accord with the soil plan. Transporting the soil to a non-Devens site triggers an even tougher regimen of testing.

Since soil erosion control is a major priority at the site, one of the first steps taken by the contractor was establishing construction staging and equipment storage areas protected by lines of staked straw wattles and siltation fencing. In addition, work crews installed siltation control barriers between the work areas and in other strategic locations.

About 11 acres of the project were cleared by subcontractor Soini Construction. This involved removing above-ground materials such as trees, brush, and debris, plus grubbing stumps, roots, and other unwanted underground materials. Max Molnar of Soini said their crew used a John Deere 853M Tracked Feller Buncher in conjunction with a Tigercat 620 Log Skidder to remove trees and a Caterpillar 329 with a root grapple rake to extract stumps. In addition, they employed a John Deere 325 Mower to remove underbrush.

After clearing the site, crews stripped and stockpiled the loam. According to McCarty Project Superintendent Michael Langelier, they stockpiled about 30,000 cubic yards of loam. McCarty’s fleet of heavy equipment then moved in, initially to excavate, sort, stockpile, and replace historical fill materials. Next, they performed balanced on-site cuts and fills to establish subgrades and elevations for building foundations.

Located on Grant Road in the Innovation and Technology Business District of Devens, the new industrial building has a north-to-south orientation and closely resembles a rectangle with an overall footprint of about 590 feet by 470 feet. Earthmoving operations within the building area have been divided into contiguous Phase One and Phase Two sequences. Phase One, the northern-most sequence, takes place first. During this sequence the following work takes place:

• Material is excavated to virgin ground. This includes removing and replacing historical fill from previous development.
• Excavated material is stockpiled on the Phase 2 area.
• The bottom of the excavation is proof rolled.
• Unsuitable material is removed from the stockpile.
• Stockpiled material is placed and compacted according to geotechnical specifications.

Phase Two operations are similar to Phase One. “Proof roll” refers to visual assessment to see if the subgrade will support subsequent fill or pavement layers. The non-technical test is often done by an engineer who simply observes a smooth drum roller or a loaded water truck passing over the excavation to see if there is any deflection of the surface.

The original work site sloped downward from south to north, with elevations varying from about 347 feet to 300 feet. In comparison, the new building’s main floor elevation is about 323 feet, so considerable cut was required. There was substantial historical fill from the prior development that had to be excavated and replaced with acceptable fill. This increased the amount of good fill needed to balance the earthmoving.

Fortunately, there was an on-site material resource in the form of natural eskers. These long, winding ridges consist of sand and gravel, have uniform shape, and resemble railroad embankments. Most eskers were formed within ice-walled tunnels by streams that flowed within and under glaciers millennia ago. As the glaciers melted during the last Ice Age, stream deposits remained, forming eskers.

At the Devens site, the eskers were between 15 and 30 feet taller than the surrounding ground. They were devoid of water and ledge and provided thousands of cubic yards of acceptable fill.

“This was a beautiful, natural gravel,” said Langelier, a 20-year construction veteran. “We moved about 67,000 yards during the two phases.”

The project design called for the construction of an enormous retaining wall to protect the northern end of the building from a steep slope. Built by Earth Retention Systems (ERS), the structure is a segmental block retaining wall that uses Diamond Pro Pin System design, according to Troy Chappell, Vice President of ERS. He said the wall is approximately 700 feet long, up to 32 feet tall, and took about 12,500 Diamond Pro Pin System specialty blocks to construct. The wall is backed by geogrid-reinforced soil, and the specialty blocks are precisely aligned by placement of two pins per block.

Once concrete for building foundation walls and piers had been poured and backfilled, ironworkers began laying out steel for the pre-engineered industrial building. Dave Allen, Owner of Dave Allen & Co., the subcontractor for steel erection, said they were a little surprised when they began laying out the columns and beams. “It took more space than we originally thought,” Allen said. “We needed 80,000 square feet.”

Allen said the heaviest components they erected each weighed about 8,000 pounds. They are using a hydraulic crane for lifting. The 65-ton Liebherr crane rented from Astro Crane has a 129-foot boom, providing plenty of reach and capacity for the long picks this job demands.

According to Langelier, the Devens project is on schedule. “We broke ground for the project in September 2023, and we’re on target for completion in January 2025,” he said.