ALLENWOOD­ — Up to four data centers could be coming to a business park along Route 15 in Union County.

That was revealed Thursday at an open house held by the developer, PNK Group of New York City, on its plans for a data center campus on property it owns and partially developed in Great Stream Commons.

One of the proposed data centers would occupy part of the 478,388 square-foot building constructed as a warehouse/distribution center. The other three would be in separate buildings yet to be constructed.

Before any of that could happen, Gregg Township would have to amend its zoning ordinance to permit data centers in commercial/manufacturing areas.

PNK’s request for such a change is before the township planning commission and the supervisors. The supervisors have scheduled a May 4 hearing.

Opposition to the data centers already is forming. Jared Welch of Allenwood, who stationed himself about a block from the open house, had more than 120 signatures on a petition opposing the centers.

Those who signed the petition cited concerns about the noise level, environmental issues and the impact on property values.

The open house in the Allenwood social hall, which was limited to Gregg Township residents, featured stations where PNK team members answered questions.

Residents were told the data center development will bring tax revenue with minimum noise, traffic and water use. They also learned:

— The facility is planned to deliver up to 300 megawatt of data center capacity across approximately 1.5-million square feet of development.

— The other three buildings would be primarily single-story structures built to support modern data center operations. Most of the construction would be off-site.

— A 69-kilovolt electric substation will be built to provide power for the data centers.

— A closed loop water system will minimize water usage.

— The facilities would have to abide by the township’s noise ordinance.

— There would be 60 to 100 tractor-trailer trucks a day if the large building becomes a distribution center compared with two to five vans if it is a data center.

PNK’s planned timetable is to retrofit part of the large building in 2027. If that phase is successful, construction of the three buildings would take place in 2029.

The company has pledged as part of its investment to provide funds for a new fire engine and establish a community fund of $2 million with contributions as phases are completed.

PNK says it wants an ongoing dialogue with residents, local officials and stakeholders.

It is pursuing the project to meet the market demand for data center capacity in the Mid-Atlantic Region it says.

The company does not have a committed tenant but one of its team members said there is interest in the retrofitted portion of the large building.

Great Stream Commons, just north of Allenwood, is where U.S. Pollution Control Inc. (USPCI) in 1990 proposed building a hazardous waste incinerator.

The plan met strong opposition from officials and residents. Union Pacific Corp., of which USPCI was a subsidy, announced in 1994 it was abandoning the project for economic reasons.

Union County ended up owning the land and selling parcels for development.