This is a condesnate tank on a natural gas well site. The liquid that accompanies the natural gas is water and condesnate and is collected in tank. This liquid is very similiar to gasoline but does not have the anti-knock additives. Many kids have fueled their pickups and cars from tanks such as this. That is if no one caught them stealing the liquid. A wind sock is on top of the tank so you can see the direction of any wind movement. Some wells produce hydrogen sulfide, the rotten eggs gas many have made in chemistry labs. This gas is posionous and needs to be avoided. It is rare that this gas leaks into the air. But signs warn you about it anyway. Tank is set in another tank to contain any spills that might occur. The sign on the tank shows that this well is owned by Kerr-McGee.