A federal effort to clean up a Superfund site in a Montgomery County borough is finished, and regulators are looking ahead to the final stages of the more than 30-year project. 

Starting in the 1930s, an asbestos manufacturing plant in Ambler dumped materials containing the hazardous mineral on the BoRit site for decades.

The Environmental Protection Agency began cleaning up the mess in the 1980s, but after sampling in the early 2000s showed high levels of asbestos remained on the site, efforts intensified. Since 2008, workers have removed materials containing asbestos, re-engineered creeks, capped the entire site with liners and clean soil, and treated millions of gallons of water in a pond on the site.

This week, the EPA released its final plan outlining the completed work, as well as how the site will be managed in the future.

In the coming years, scientists will sample water, soil and air for asbestos to make sure the cleanup is working as intended. The EPA will use federal asbestos standards for water, but the agency has developed site-specific limits for how much asbestos is acceptable in soil and air.

“It’s not necessarily zero asbestos, but it’s a low amount that would be expected to be protective of human health,” said John Epps, chief of the EPA's Eastern Pennsylvania Superfund Branch, who is overseeing the cleanup.

Much of the testing will be "activity-based sampling." Workers will simulate activities that are expected to take place on the land, such as walking or raking leaves, while wearing air monitors. The idea is to see what level of exposure, if any, people using the land might experience.

The EPA will conduct testing and maintenance for two years before turning the site over to the Pennsylvania Department of Environmental Protection. To avoid stirring up toxins, the agency will also codify restrictions on future use or redevelopment of the site before handing it over to the state to manage.

While most of the site currently sits unused and empty, one section has become a waterfowl preserve. Another parcel could become a public park.

“We’re very confident in the capping work that we did out there, that it will be a safe place for kids to play and that the park reuse will be appropriate," said Epps. "We’ll continue to monitor and make sure that there aren’t any exposures and that the remedy is functioning as it was designed."