After four years and numerous stumbles, Israeli-based Elcon Recycling is moving forward with plans to bring a hazardous wastewater treatment plant to Falls Township, and residents are gearing up for a fight.

The company wants to build a 70,000-square-foot commercial facility that would annually treat between 150,000 to 210,000 tons of wastewater produced by electronics, pharmaceutical, chemical, and metals manufacturing. The toxic material would be processed in a plant on the Keystone Industrial Port Complex in Falls, once the home of U.S. Steel. Eventually, Elcon said, it would add an additional 70,000 square feet to its facility, bringing the total size of the plant to 140,000 square feet.

But residents of the densely populated town along the Delaware River worry that the plant could bring air pollution or even contaminate the river, which is a major source of drinking water for more than 20 towns in Bucks County.

“The whole county is going to be affected by this," said Kim Rock, a Lower Makefield resident. “It’s scary how far it’s progressing."

Elcon has insisted that the plant would pose no hazard to the surrounding community. Thermal oxidation, one of its main methods of treating wastewater, would produce air emissions nearly free of pollutants, company officials said. The proposed facility would not treat wastewater that was radioactive or the product of hydraulic fracking, and toxic fluids would be transported by land, not the river.

Elcon also has touted the 50 full-time jobs the plant will bring, along with 120 temporary construction jobs.

Efforts to reach Elcon were unsuccessful. Company officials did not return e-mails seeking comment about the project.

The initial plans the company submitted to the state Department of Environmental Protection have been amended numerous times in response to what the agency cited as “deficiencies" and incomplete paperwork.

Elcon is now nearing the end of the DEP’s technical review, a 10-month period in which agency officials assess whether a project is appropriate for the proposed location by weighing environmental, social, and economic factors.

As part of that review, the DEP will hold a public forum on the project next month at the Sheraton Hotel in Langhorne. Anti-Elcon activists are encouraging residents to attend.

“I absolutely believe we can prevent this from happening,” said Russell Zerbo, advocacy coordinator for the Philadelphia-based nonprofit Clean Air Council.

Falls Township officials, too, have been reviewing Elcon’s plans.

Robert Harvie, board chairman of Falls Township’s Board of Supervisors, said in an email, are “well aware” of residents’ concerns.

The DEP officials who have been reviewing the project will make a final recommendation in May, and DEP Secretary Patrick McDonnell will have the final word on whether the plant will be built. Agency officials said his decision could come as early as this summer.