I keep about 20 gallons, I don't know of any local ordinances (I just went on the local city website and checked). In plastic gas jugs, unvented, that I bought from Auto Zone or Pep Boys or somewhere.

I had 20 gallons that sat for about a year, last year, put it in the motor home before moving north from Southern Cal, worked fine. I didn't test the mileage since I was driving with a loaded trailer anyway.

I do keep it away from my water supply, in case of some leeching (leaching?)and check it during hot spells to make sure no pressure build up.

But now, between the propane post and this one, you guys have got me nervous!