Good question Carol, I haven't tried to remove the bench, but the bottom does seem pretty secure. I'll try to investigate further tomorrow.
I did measure the tank, and it is the same 12 gal that Scamp
has on their website designated for post 1990 trailers. Same dimensions. It is so far away from the outside wall, I assume that they just put it in in a different position for some reason. If the tank were moved so that the drain with the stopcock used the outermost hole in the floor, and the overflow used the inner hole instead of the way it is now, it seems that would give me another 3 inches or so to fit my hand down along the inside edge.
I cannot think of a reason that someone would have make this change, other than shear brain fart when re-installing.
Anyway, I know what needs to be done, so will attempt it at some point. Right now, I'm getting a fair amount of black crud out of the tank and lines when I pump the water. Actually got two very dead spiders out of it too. No leaks
that I can see at the tank end, but the hand pump leaks
around the base. I've read some folks have been successful repairing these pumps, but most folks seem to recommend just buying a new one, or switching to an electric.
I think at this point, I'll just continue to use the old pump and see if I can get all the black crud out with bleach water. If successful, I'll go ahead and install a new hand pump - kinda leaning that way as opposed to electric since there is no bath and I hope to do a substantial amount of boon docking. Less battery
On Monday I should receive the new sink drain trap - hopefully I got the right size. The one that was in it had the nipple that the drain line attaches to broken off. I'll get that put back together, then It will make pumping the bleach water through the system easier.
If I get the water flowing clear, then I'll just treat any tank water with Aqua Mira, the same water purification I use when backpacking. It was initially marketed to sanitize and keep storage tank water sweet. Kills most all bacteria if used properly, so will make the water fine for hand/dish/hair washing. Will cook/drink bottled water for the time being.
If I do end up removing the bench, I will probably replace the entire water system, line and all, plus re-install the tank in the proper position.
Anyway, so far I've only found these small, annoying things to fix on this 16 year old trailer, so I'm happy. I anticipate needing a new axle
in the years to come, but I'll cross that bridge when It comes.