I am curious if the solution is from new sources (fracking and cracking) or historical sources like the Clairton coke works. I've heard that there are several n

I am curious if the solution is from new sources (fracking and cracking) or historical sources like the Clairton coke works. I've heard that there are several new ethane cracker plants that have come online in recent years to support the fracking industry. From what I understand the long standing polluters like the clairton coke works are still going strong and there have been several new cracking plants built to support the fracking industry.