Pile driving for Amazon’s $2.5-billion HQ2 project in Arlington, Va., finished two weeks ahead of schedule and construction officials say concrete work will begin this fall, pending approvals.

On April 15, crews began driving 330 piles, each measuring between 60 to 70 ft in length, to provide temporary support of the excavation site at Amazon’s Metropolitan Park campus. The work was expected to require six weeks to complete, but instead wrapped up on May 15, according to a spokeswoman for Clark Construction Group, the project's contractor. “It was a good outcome to a challenging effort," she said.

Crews gained time in the schedule “because of favorable soil conditions on site,” the spokeswoman said. The Arlington soil is soft and loamy.

The next phase of work is a mass excavation to remove 444,000 cu yds of soil from the site in the next five months. As of May 15, 75,000 cu yrds of soil had been removed. "Utility work continues and concrete work at the site begins in fall,” she added. Work on the project began in January.

The issue of noise from the pile-driving operation had been a concern for Pentagon City and Crystal City residents, a few hundred of which had signed an online petition asking for work to stop until the stay-at-home orders lifted and many of them returned to working from their regular places of work. However, the construction is considered an essential service under Virginia's stay-at-home order, county officials said.

Gina Wimpey, spokeswoman for Arlington Community Planning, Housing and Development, said her office never “received any formal complaints associated specifically with pile driving at the Amazon site.”

She added, “We did receive a number of inquiries a few weeks back about general construction noise and the request from some constituents who are working at home to have the construction projects rescheduled; however, the construction activity, and associated noise, was not in violation of the Noise Control Ordinance or Site Plan Conditions for the site."

A concrete batch plant was approved in April to help decrease daytime truck traffic through neighborhoods, now more populated than usual because of the stay-at-home order. Arlington County’s planning director Bob Duffy says the temporary concrete mixing plant will present less of a disruption to the neighborhood than if concrete were manufactured off site and trucked in.

While the county has approved a batch plant for the site, “There are numerous details regarding the plant that have not been finalized," the Clark spokeswoman said. The contractor estimates it will erect the batch plant in late summer, roughly a month before cast-in-place concrete work begins.

Designed by ZGF Architects and developed by JBG Smith, Amazon HQ2 plans call for two, 22-story towers to be built by 2023. The first half of HQ2 at Metropolitan Park will include office space for 12,500 employees, a 2,000-space underground parking garage and street-level retail space.