GUILDERLAND — At its Sept. 12 meeting, the Guilderland School Board voted to affix a notice to the deed for property the school district owns — just north of the football field and including the northern end of the new bus depot — stating that any future construction on the land would involve a risk of vapor intrusion and that, in the event of planned development, the Army Corps of Engineers has offered to investigate and mitigate the risk.

Gregory Goepfert, project manager for the Army Corps, explained this week what vapor intrusion means. There are areas within the land owned by the school district that show higher soil-gas concentrations; the risk is that, if an enclosed building were built at some point in the future, vapors attached to soils could potentially rise through the basement or foundation and collect within the indoor air.

The chemicals that are a potential concern for a future building are, Goepfert said, trichloroethene, a volatile organic compound typically used as a degreaser, and perchlorethylene, a volatile organic compound primarily used for dry-cleaning fabrics and degreasing metals.

Goepfert stressed that there is no risk now. In a clean-up operation in 2002, hundreds of tons of soil were removed and replaced, and follow-up testing of soil-gas levels beneath the bus depot were, he said, “way below action levels.”

A deed notice was the most sure way to memorialize the risk and the services offered, said Neil Sanders, the school district’s assistant superintendent for business.

The notice will “stand the test of time,” he said. “People transitioning, memories fading — it’s affixed to the deed itself,” Sanders said.

The land, about 1,000 feet long and 400 feet wide at its widest point, runs in an undulating line from the northwest tip of Area of Concern 3, which is a former burn-pit area at a former Army depot in Guilderland Center. Most of the decommissioned depot land is now owned by Northeastern Industrial Park. The problematic land runs across the top of the school district’s new bus depot, and through Guilderland’s parking lot to the north of the football field. It is just south of the Black Creek, which feeds the Watervliet Reservoir, where Guilderland residents get most of their water.

The deed notice was recommended to the district by the Army Corps of Engineers, Sanders said.

The school district has been assured by the Army Corps that the land is safe for its current use, according to the resolution voted on by the board. But if, in the future, an owner were to construct a new building on this land, this activity would entail a risk; in that case, the Army Corps of Engineers would offer its services and assistance to determine if there were still a risk and to mitigate that risk as much as possible, the resolution says.

The Army Corps of Engineers would require at least a year’s notice, prior to the start of any construction, the resolution states.

The board voted to file, for a fee not to exceed $200, the deed notice outlining the risk and the availability of mitigation services in order “to ensure student, staff, and community safety,” according to the resolution.