The caverns the oil are stored in are old salt mines that were repurposed but that means the walls and pillars are made of salt. They pump water into the caverns to float the oil to the top when they extract it.

The water itself already dissolves the salt but if you get down to 70 million barrels then you start getting salt water touching on the plumbing which corrodes it, as well as the last bits of oil are sludgy and can also foul the pipes.

The strategic oil reserves were not built with an expectation of being used perpetually, they had a lifetime expectation of 5 full drawdowns and we’ve repeatedly done fractional drawdowns.

I only learned this a year ago and felt like we as the public have been mislead as growing up and as an adult the government always presented drawdowns as something that wouldn’t be a problem, we could always just top it back up later. And although I hate ever doing both sides arguments that’s been the impression I got from every admin since Clinton.