An F250 or GM2500 ton won't last very long hauling that much weight.
Notice that he uses a 1 ton (F350 / GM 3500 / Dodge 3500)for a 500
gallon spray tank, BUT you don't use spray tanks like you will be using
your water tank, and you have about 1000 pounds in extra water over the
500 gallons.
Also if the tank pictured is the one you plan to use you can't use a P/U
anyway. It won't fit in the bed between the wheel wells.
So you need either something with a flat bed OR a trailer. Or a purpose
built hauler.
You also may want to check with the DMV on the requirements on an older
fire engine. You won't be using it as a fire truck and may not need to
have a CDL to operate it as a not for hire vehicle. Not sure where you
are in Cali. but you can operate a vehicle up to 26,000 pounds GVW
without a CDL. and many older fire engines fall under that rating!
Speaking from experience as a fireman here in NY. If you were out here
my FD has one you could buy cheap. BUT the gas to drive it out there
would probably cover the national debt!
My neighbor hauls water in a purpose built trailer.
He started with a tank like this one
http://www.tractorsupply.com/en/store/leg-style-storage-tank-525-gal
on a small dump style trailer like this.
http://santabarbara.craigslist.org/for/4557408155.html
He mounted the pump on the back.
His current trailer is like this one
http://santabarbara.craigslist.org/hvo/4513045185.html
And he has a 1,000 gallon tank like this
http://www.tractorsupply.com/en/store/leg-style-storage-tank-1025-gal
on it.
He bought the tank new and the trailer used. He also had to get
certified by the state to haul potable water and the new tank was a BIG
help with that as they wanted proof that it had never hauled anything "bad".
Nice thing with a trailer is that you can just park it out of the way
when not needed. You just need to watch out how heavy it is. Anything
over 10,000 pounds also requires a CDL.
You may want to consider your tank on a purpose built trailer. If you
figure you fill it with 625 gallons you have 5,200 pounds of water, Tank
weight of around 120-150 pounds. You are in the 5,400 pound area. Add in
a trailer and your around 8,000 pounds.
Or look at these for an idea.
http://www.water-storage-containers.com/portablewaterstorage.html
Their 800 gallon unit has a GVW of 9200 pounds.
If it was me I'd hunt up a medium duty truck, either an old fire tanker,
ex military 2.5 ton (M35A3, M44 or M1078 series)or common cargo truck
like a GM top kick or Ford F650/750 series. Paint WATER and not for hire
on it, add a tank and register it at 24,000 pounds and start hauling water.
What would be ideal would be to find an M-50 water tanker. They have a
1000 gallon baffled tank.
http://olive-drab.com/idphoto/id_photos_m50water.php
--
Steve W.