This happened quite a while ago, but similar things are still going on today. Recently, I was considering a job in Pennsylvania, which unfortunately was several miles from the Marcus Hook Sunoco refinery (which has been in operation since 1902). It was recently fined $750,000 for "illegal modifications to equipment that allowed tons of potentially hazardous gases to be released into the air over two years." ...
"According to DNREC, the flare was modified at some point to receive gases from multiple sources throughout the Marcus Hook side of the facility, although no permit for those changes was ever sought by the company."
Those gases included hydrogen fluoride among other things.
https://www.amazon.com/Full-Body-Burden-Growing-Nuclear-eboo...
An interview with the author was in the Atlantic a few years ago:
https://www.theatlantic.com/national/archive/2012/09/a-septe...
This happened quite a while ago, but similar things are still going on today. Recently, I was considering a job in Pennsylvania, which unfortunately was several miles from the Marcus Hook Sunoco refinery (which has been in operation since 1902). It was recently fined $750,000 for "illegal modifications to equipment that allowed tons of potentially hazardous gases to be released into the air over two years." ...
"According to DNREC, the flare was modified at some point to receive gases from multiple sources throughout the Marcus Hook side of the facility, although no permit for those changes was ever sought by the company."
Those gases included hydrogen fluoride among other things.
https://www.delawareonline.com/story/money/business/2018/03/...