The ability to run near-zero emissions ethylene production has been around for years.
And, it's not expensive. In order to get permitting & right to operate, the systems have to built to PSM (process safety management) code.
Those include all the instrumentation, infrastructure, containment, and monitors. The money is already spent so doing it right costs nothing extra.
On top of that, I've been in Shell chem plants. They are typically run by the book. And Shell is a Responsible Care manufacturer.
I think local management will be looking for work very soon.