The law proposal passed with the larger size cap does not contain such a provision, he said.
"In the local law that was passed, the Bender Melon Farm could be subdivided multiple times, and multiple projects of 250,000 feet could be built in each of those subdivisions," he said. "So it's not just one project of 250,000 square feet, it's multiple projects of 250,000 square feet."
Discussions about New Scotland's zoning laws were prompted by a proposal from by Sphere Development LLC to place a 137,000-square-foot anchor retail store at the corner of Routes 85 and 85A, and a desire for the town to upgrade the laws to coincide closer with its comprehensive plan.
The county's planning board will hear the law and potentially make a decision on the size cap on May 16. A public hearing is then scheduled to be held on the new local law on June 17.
Mackey said the Bethlehem board can help show support, as it has in the past by attending public hearings in New Scotland, by sending a letter of opposition to county and speaking out against the possible negative effects such a large project could have.
"I think the Town of Bethlehem has a very significant role to play should you be concerned with what's happening just over the town line," Mackey told the board. "I guess I would urge the town to consider your role in communicating with the county planning board about traffic impacts and environmental impacts or just the impact on the hamlet of Slingerlands."
Bethlehem Councilman Mark Hennessey, who has vocally opposed the development, said the larger size cap was the wrong fit.
"I think it's of deep importance to the people who live in Slingerlands," he said. "I think as it is envisioned right now, I don't think it would be a positive development for Slingerlands. I think it would be a negative one."
" Reporter Dan Sabbatino contributed to this article