We have some good friends here in our local area and just up the mountain a bit friends own a small parcel of land right on the border of the rainforest.
They have a number of large and old citrus and fruit trees, that do extremely well in the rainforest environment.
The house here at Arborlon has a somewhat primitive grey water system. Water from the bathroom sink, kitchen sink, and shower drains to a grey water reservoir just outside the house in our back yard. it is a small-ish concrete tank set in the ground. It has a submersible dirty water pump that runs intermittently, and the outlet is just a grey water pipe extended down the hill below the house.