The Pennsylvania Department of Environmental Protection (DEP) has approved a key permit amendment that would allow Shell Chemical Appalachia LLC to discharge wastewater from a treatment plant that it plans to build at the site of its proposed ethane cracker in Beaver County.

The company is nearly finished with the two-year process of preparing the 400-acre site in Western Pennsylvania, where it plans to move forward later this year with constructing a multi-billion dollar petrochemical complex.

The DEP approved an amendment to the facility’s National Pollution Discharge Elimination System (NPDES) permit, which authorized discharges associated with demolition, earthmoving and other site-prep construction activities. Stormwater treatment was required during the transitional phase because of legacy contamination from the zinc smelting operations.

Shell has worked to clean up the property, and the amended NPDES permit would allow it to discharge treated wastewater into the Ohio River and two streams once the cracker is operational, which is expected sometime in the early 2020s. The facility is to consume about 100,000 b/d of ethane and produce 3.5 million pounds/year of polyethylene.

Earlier this year, the company received a local conditional-use permit that allows it to move forward with plant construction. The air quality permit it received from the DEP in 2015 was modified and approved in December.