He doesn't mean SALT mines.
He means where he works.
The Big Bang Theory Season 3, Episode 10
born amidst SALT and smoke.
Game of Thrones Season 2, Episode 4
Lucy, you must remember to have
the SALT and pepper shakers wiped.
Breaking Bad Season 2, Episode 11
What if we were to go
as dinner table favorites, SALT and pepper?
The Big Bang Theory Season 6, Episode 5
Can you please pass the SALT?
The Big Bang Theory Season 8, Episode 20