MILTON — Despite a long, cold winter, a hot spring, an extremely rainy June and a thunderstormy July, the Interstate 89 Lamoille Bridge project has been pushing along

“We have accelerated the work,” said Nicolas Belzil, Tetra Tech project engineer and assistant to senior project manager, Matthew Palmer, on Tuesday.

Crews are working most Saturdays, and there are also plans for crews to work next winter in order for the design-build project to be done close to its June 2016 completion date. Some additional work is expected to extend into the fall of 2016, too.

This week, on a bright, sunny afternoon, workers were packing up to go home after an eight-hour day in the heat. Belzil walked the Milton site and explained the current status of the project.

“We [are building] the bridge in three parts,” said Belzil. Following project permitting begun in August 2013 and construction in February 2014, a bridge deck was erected between the two existing bridges, which were originally built in 1967. The west-side old bridge was then knocked down this past winter, and it is now being rebuilt to connect with the new middle deck.

Steel beams, covered with shear studs and metal deck pans, were erected for the west side of the new bridge earlier this month. Subcontractors High Steel of Lancaster, Pa. and Structural Services, Inc. of Bethlehem, Pa. helped with that part of the project.

A barge with a massive crane still floated on the Lamoille River earlier this week.

“They finished last week,” said Belzil. “That was a big part of our schedule – we call that a ‘critical task.’ We did well.”

He added, “Now it’s our workers – the construction workers – that will pour the concrete on the deck.”

The pour is scheduled to start next week, and on Tuesday, workers were prepping the area by laying down steel rebar (reinforcing bars). According to Belzil, the concrete pour may cause some delays in the southbound side of the highway when concrete trucks are there. The bridge deck concrete is expected to require five pours over the next few weeks.

“We’ll close the right lane on some days,” he said. Belzil added that Tetra Tech has restrictions on lane closures due to high volume traffic times – i.e. when Burlington commuters and going to and coming home from work.

While working on the surface of the bridge, Tetra Tech is maintaining the structure’s underside, too. Environmental buffers like silt fences, stone, rock-bed ditches and turbidity curtains – signaled by floating yellow tubes in the water – are set up to protect the Lamoille River and its inhabitants from erosion and run-off.

Once the west side of the new bridge is complete, traffic will be shifted over, and – if everything stays on track – the old east bridge will be knocked down and rebuilt next winter, spring and summer. The final product will be one, 106-foot wide bridge, having four lanes divided between northbound and southbound traffic.

Belzil said the bridge would have large shoulders and a concrete barrier in the center.

In total, the Vermont Agency of Transportation project is expected to take 36 months and cost $23.1 million to complete. About 90 percent of the funds for the project are from the Federal Highway Administration.