LYNDHURST - A project is underway to contain contaminated soil at a North Jersey park.

Dredging has been going on since the spring at Riverside County Park in Lyndhurst.

Crews are now building a barrier to contain the mud along the banks of the Passaic. The mud is contaminated with dioxins, mercury and PCBs, mainly from a factory that dumped chemicals into the river in the 1960s.

The goal of the capping effort is to place a layer of sand and carbon over the mud to prevent contaminants from escaping.

Residents have their concerns about the project. "I'm for it, but I hope they're not going to interrupt the navigable parts of the river or create choke-points that will prevent drainage from storms and debris and things like that," says Dave Popek.

More than 16,000 cubic yards of contaminated sediment has been removed from the area so far.

Experts blame Hurricane Irene for pushing a lot of the pollution on the river banks.