Billions of dollars and five years of construction work; that’s what the future holds for Beaver County and the surrounding region now that Royal Dutch Shell’s ethalyne cracker plant is coming to town.

Shell says the construction project — which will build the ethane cracker, two units to convert ethylene to polyethelyne pellets, a power plant that runs off natural gas, a loading dock and a wastewater plant — will employ 6,000 workers.

Allegheny County Executive Rich Fitzgerald characterized it in a way sports fans might better comprehend: that’s the equivalent of about 25 stadium projects, he said. Shell hasn’t put a price tag on the project, but estimates of the total cost of constructing the facility have pegged $6 billion as a reasonable guess.

Once the facility is operational, which Shell projects will begin sometime after 2020, the plant, which converts ethane into the basic components of common plastic products, will employ 600 workers permanently.

The true promise of this facility won’t be realized in the short-term. The cracker — the first in a generation to be built outside the Gulf Coast — is both a symbol of Pennsylvania’s energy bona fides and a real-world changing-of-the-guard for this region’s heavy industry. To live up to Shell’s promise that the facility would be “world scale,” the plant would need to produce more than a million tons of ethylene per year.

The plant has the potential to reinvigorate a stagnating natural gas boom in Pennsylvania as well as blunt the cascade of economic pain felt by hundreds of coal industry employees — suffering amid low energy prices, falling demand for their product, and a CO2 emissions crackdown by the Obama Administration. In 2012, Shell estimated that the plant could create 10,000 jobs in the region

Opportunity, however, is not without risk. And concerns revolve around how the plant will impact the already-dubious air quality of Western Pennsylvania — a perennial recipient of failing grades in the American Lung Association’s yearly air quality report.

Unlike its rosy jobs projections Shell has, in the past, declined to discuss the potential environmental impact associated with the plant. But cracker facilities emit substances like Nitrogen Oxides (NOx) and Volatile Organic Compounds (VOCs). Both are precursors to the ozone pollution that already troubles this region.

In 2012, PublicSource reported that a similar Shell cracker plant in Norco, La., if located here, would become the largest emitter of VOCs in the region, more than doubling the current leader. It would also be among the region’s top 10 NOx emitters.

The cracker plant here will use the latest technology, so it’s unclear whether that comparison will bear out.

It’s also worth noting that the company has already invested $80 million for environmental remediation as it converted the site of a former zinc smelting facility.

But cleaning up someone else’s mess and inflicting the unavoidable cost of doing business on the environment are two very different things.

Shell should get points for doing the right thing as it prepared for construction, but it needs to acknowledge air quality concerns associated with this project, and address them directly and honestly.

Risk and reward: this cracker plant has plenty of both.