New Jersey regulators have issued the final state permit needed for a controversial natural gas pipeline project.

The Department of Environmental Protection has approved an air quality permit for a Williams Transco compressor station tied to the Northeast Supply Enhancement, or NESI pipeline.

The permit clears the way for construction of that station.

It's a 32,000 horsepower gas fired facility planned for Franklin Township in Somerset County.

But the broader NESI project also includes new pipeline segments in Old Bridge and a 23 mile underwater line beneath the Raritan Bay and New York Harbor.

State and federal water permits were approved late last year following years of earlier rejections.

WILLIAMS Transco says the project will help deliver reliable natural gas supplies to New York during peak demand.

But environmental groups argue the compressor station will worsen air quality here and increase toxic emissions, despite promised air monitoring requirements.

Those groups, including the Sierra Club, are vowing to continue legal challenges as construction moves closer.