The Conservation Commission has unanimously approved plans by Bridgewater Associates for upgrades at its 15.84-acre Glendinning campus.

The commission’s Wednesday special meeting continued a four-hour public hearing July 29, where board members felt there were many unanswered questions about the hedge fund’s plans, including some concerning a proposed underground parking garage and the impact of the work on wetlands.

Bridgewater’s lawyer, Eric Bernheim of Halloran and Sage, said the applicant responded in writing to “numerous questions received” since that meeting and Craig Lapinski, a civil engineer with Fuss & O’Neill, said, “We’ve been careful to address every comment we’ve gotten.”

The project;s impact on wetlands remained an issue for some commission members, but they were assured that only a small area of wetlands, most described as “low functioning,” would be disturbed during construction.

The panel also discussed the removal of about 10,000 cubic yards of hazardous materials on the property during remediation, in particular, the safe handling of the material during that time. Trucks would be lined up to take the material off-site so there won;t be stockpiling, commission members were told.

Public access to the property and use of adjacent waterways — the three rivers that run through the property — will remain the same, the way it has been since Bridgewater occupied the property, they were told. And the Aspetuck Land Trust would still have access to its property, via an existing easement.

“We don’t plan to make things difficult,” said Bernheim. “We won’t be putting up signs.”

But, he noted, there could be some restricted access during construction, including when a septic system is being installed and remediation is taking place. Like any construction site, he said, there will be a fence around it.

Among the conditions imposed by the commission prior to giving its approval was that any hazardous spills during construction be reported immediately.

The approval, added Commission Chairwoman Patricia Shea, “may be revoked or suspended” if any of the conditions aren’t met.

Bridgewater’s application for the project, filed earlier this year with the Planning and Zoning Commission, calls for a two-story underground parking garage that would eliminate the approximately 160 above-ground parking spaces that lie in a flood plain adjacent to the main headquarters on Glendinning Place.

It also involves the renovation of two of the five buildings on the Bridgewater property, which is a designated Design Development District.

The entire project should take 24 months to complete. During that time, the business will relocate some workers, about 300, to other locations.

The plan needs a review by other town boards and commissions before a formal proposal goes back to the P&Z for final action.

The headquarters of Bridgewater Associates, the world's largest hedge fund, has been located in town for the past 17 years. It had announced plans last year to move its corporate offices to Stamford. Despite $115 million in state incentives for the firm to move to a new waterfront headquarters in that city, the project became mired in local zoning disputes and Bridgewater ultimately pulled out.

Bridgewater Associates was the town's fourth largest taxpayer on the 2014 grand list with holdings assessed at $22,053,470.