I rented a house near a landfill for 6 years.
The well was deep ~500 feet.
Intermittently, 'air' would come out of the spout when the faucet was turned on.
At one point, the landlord was compelled by the Health Department to test my water.
Tech came out, and before sampling, he flamed the the spout.
WHOOSH! With blue flame.
Turns out, the 'air' in my lines was actually methane, a by-product of bacterial metabolism.
[The pressure tank/pump system in the house was ancient.]
Just a consideration.
-Paul