Is the tank on a stand, or higher ground? The steep terrain of my property is a pain in some ways, but it allowed me to get my water tank eighty vertical feet up.
It's my second interation of a 2 story outhouse. I had 24' - 6x6 square marine pilings I put a couple feet in the ground and built a platform on top and a simple shed roof on top making a 10x10 room for the tank, and cantilevered roof 12 x 18. From the ground I have seven steps up to a deck with 6' of open deck under roof where I have a clawfoot tub and "inside" the pilings is the toilet room with a really high ceiling, all enclosed with salvaged vinyl siding. I backfilled the area around the pilings, some it it coming from digging the 1500 gallon holding tank mostly into the ground, the Tolliet drains directly into the tank, which is vented all the way to the top- no leechfield needed. We only poop in it in the wintertime, all summer the effluent just clarifies and eventually is evaporated off, never more than 4 or 5 inches of "poop" in the tank, and its as big as a volkwagon...... I can build any structure from below grade to finish trim and millwork, but prefer post and beam framing, and enjoy working alone. The tank has alot of head pressure being so high, and I can outdoor shower or run a 100 garden hose to the main cabin and have water pressure on gravity alone. The fluid head pressure is enough to run a 3200psi pressure washer when I need to wash the stairs and decks off or clean a tractor or Skidsteer of mud. I have a Rinai gas HWH that runs on the gravity, so I can get a bath in the clawfoot under the stars If I am reallly muddy/nasty.
I ran a 2" pvc into the top and down the ouside wall and have a few valves to work with, one of which I use a Honda 4 stroke 1hp Water pump from the IBC with my cheap city water ( chlorinated and flourinated) and pump it up through the 2" standpipe to the holding tank until its full- which creates the siphon effect for gravity flow down later.
The tank room is enclosed only on three sides, I left the fourth side open and its a generous space for two people to hunt from, even with the tank in it. (Its a PCO slide in truck tank- looks a little like a mushroom. Has a 12" manhole in the top, never been but fresh water in it, and it has no, drain cut in)
I dont think there's eight vertical feet of elevation change within 200 miles of me here in Florida..... JK, but really, the highest points in this coastal couoty are the three or four landfills. The Honda Water pump has no problem pumping up until it cant (gravity), but its easy to keep pumping from one to the next, you just need more tanks, in a cascade.
My cabin on pilings is (has been) ready to put the kitchen and bathroom in it this winter, and I have a couple of nice solar panels to install and a battery bank on the pole barn, so i have projects to do that are affordable, just batteries to purchase, but I also have to enlcose the ends of the pole barn with the two 12' garage doors I've been saving, too. The solar will become real important for 12v LED lighting in the barn once I enclose it. 32x16x16H. The cabin toilet will get its own 500g holding tank, and I will pump it across the landing as needed to the huge tank. The gray water will also get a tank and I will send it seperate, The fresh water supply will get a new tank under the cabin as well. Tanks are cheap. I don't really have plans to dig a well, but I can get water at 15' jetting through the limestone, and have chemists that work for my city water supply who will test it, its possible it may be better water than 60 or 80', but I dont use enough to want a pump to maintain. We carry a carboy or three of water from home for cooking, easy.