GIBSONIA — Shell’s ethane cracker plant in Monaca, Beaver County, will employ 600 people when it opens in the early 2020s.

A Shell official discussed the plant development at a meeting of the Pittsburgh North Regional Chamber of Commerce at the St. Barnabas Health System campus Friday.

Michael Marr, Shell business integration lead, reviewed development of the plant site, the home of the former Horsehead zinc smelting plant.

The date to start construction of the cracker plant hasn’t been determined and the plant will start operating sometime in the “early 2020s,” Marr said.

Construction will require 5,000 to 6,000 people and the plant will need 600 employees, he said.

“There will be 600 permanent jobs at the site,” Marr said.

The plant jobs will include chemical, mechanical and electrical engineers, equipment operators and safety and environmental staff, he said.

Ethane extracted from natural gas will be heated to 1,600 degrees Fahrenheit to crack its molecules. It is then cooled and pressurized to convert it into ethylene, which is turned into tiny polyethylene pellets that will be sold to producers of plastic products such as packaging, containers, lawn furniture and the hard hats that construction and plant workers will wear, Marr said. Polyethylene is also heavily used in the pharmaceutical industry, he said.

“More than 70 percent of the polyethylene North America customer base is within a 700 mile radius of Pittsburgh,” Marr said.

Shell spent $80 million over two years to remediate the site, remove the old zinc smelter and cover the site with 7 million cubic yards of dirt, he said.

The company also built a mile-long culvert to direct stormwater runoff into the Ohio River, removed invasive plant species from the river bank and planted native trees and widened and relocated Route 18, which used to run through the site, he said.

Shell will build a power plant capable of producing 250 megawatts per day. The plant will use half the power and the other half will be added to the electric service power grid, Marr said.

He said the company paid to remove a township water plant and wells which were near the site, and built a new water plant away from the site.

Three natural-gas-fired turbine generators will power the plant, which will also have a raw water plant that will treat water from the river for use in the plant and discharge clean water back into the river, he said.

The facility will have 95 miles of piping and 25 tons of steel in its construction.

James Roddey, former Allegheny County executive, said the plant will attract manufacturers that use polyethylene to the area.

“It will be a magnet for chemical companies,” Roddey said.

David Spigelmyer, president of the Marcellus Shale Coalition, said rebounding natural gas prices this year led producers to drill 700 wells, about 200 more than last year, and more than 5 trillion cubic feet of gas will be produced this year.

Consumer gas prices have fallen 70 to 80 percent since the shale boom began in 2008 and consumer electric prices also have fallen because of lower production costs, he said.

The impact fee the state charges producers generated $204 million in 2012 and $173 million, including $26.4 million for Butler County, in 2017, he said.

The decrease comes from increased drilling efficiency. Fewer drilling rigs are needed because unconventional lateral drilling can reach 7,000 to 10,000 feet away from a well pad and eight to 10 wells can be drilled from one pad, Spigelmyer said.

Several years go, lateral drilling could reach 2,500 to 3,000 feet from the pad and one to three wells could be drilled from one pad, he said.

Of the nearly 10,000 unconventional wells drilled since 2008, about 2,000 are not in production because they have not been completed or there are no pipelines to connect them to, Spigelmyer said.