All that was done before meaningful environmental regulations, and plants dumped contaminated waste.
It is estimated there could be up to 3 million tons of asbestos waste spread across 66 acres.
There are four main sites on or near the Wissahickon Creek. Years ago, the EPA covered the worst of them with a mountain of dirt to keep the asbestos from blowing into the air and becoming a health hazard.
But elsewhere there are outcroppings, where the asbestos looks like snow on the ground.
The EPA is spending millions for a new covering, but for some that's just sweeping the problem under the rug.
"It's just a temporary solution, like a little band aid, if you will," said Lynn Hoffman of Citizens for a Better Ambler.
Sharon McCormick, also of Citizens for a Better Ambler, wants the EPA to change course.
"We want the EPA not to put a band aid on this problem, but to actually sink their teeth in it and solve it for us," she said.
They propose the EPA should deal with the asbestos problem by using high-temperature technology from west coast firm ARI Technologies, which has been used by the Navy to turn asbestos into a sort of environmentally safe gravel.
"ARI has developed a process that destroys asbestos with 100% efficiency," said Dale Timmons with ARI Technologies. "By that we mean it destroys every single fiber."
The process is not cheap, costing an estimated $135 per ton. Multiply that by 3 million, and that means this project could come with a big price tag.
Citizens for a Better Ambler plans to roll out its vision at a Wednesday night meeting. Officials from the EPA are expected to attend.