The shop does not have mains or sewer connections, and is unlikely to ever get them, yet there are certain activities (e.g. screenprinting) for which the shop could really use to have running water, and it'd also be nice to be able to wash hands at the shop, and not have to empty and maintainthe fire toilets.
At present we have a surplus water heater to use as a fresh water tank. Actual introduction of fresh water will require several steps:
Phase 1: A Sink
There is a sink in the upstairs washroom. To make it work, we'd need a pump to provide pressure from the tank water, plumbing to hook everything together, and a suitable system to discharge grey water (e.g. a pipe leading to the alley with a metal strainer on it). We'd also need a good mechanism to refill the water tank, and it'd be nice to have a gauge that could tell us how full it is.
Phase 2: A Flush Toilet
This phase would probably see the replacement of the upstairs fire toilet with a flush toilet, and the installation of a sewage holding tank downstairs. To use the toilet, we'd need to contract a honey truck to remove the sewage from the tank. For this stage, we'd need a tank, a toilet, plumbing to get water from the tank to the toilet, plumbing to get waste from the toilet to the tank, plumbing to allow pumping out of the tank, and plumbing to vent the tank. A gauge showing how full the sewage tank is would also be a nice feature.
Phase 3: Getting Fancy
This isn't a real phase, but an opportunity to hack features into the plumbing system, like having a sewage tank sensor/gauge that automagically orders a honey truck when the tank is getting too full, storing grey water (and rain water?) for toilet flushing, instead of making people refill the fresh water tank quite so often, or setting up a rainwater collection/treatment system to further reduce the need for fresh water refills.