When I first started in the car wash business, reclamated water was (and I presume, still is) a big deal. The system we had was a multi-tank, underground system that operated much like a biological filter in a fish tank, except the “bugs” (as VerWater put it, which I must note has completely changed it’s environmental/business emphasis) would “eat” the by-products of a car wash system, notably the soaps and waxes.
It was a multi-tank system that the owner of the business employed, costing a fortune, with an initial collection tank, an overflow into an “aeration tank” to reduce odor, and then into a couple of underground “biomass” tanks, where we regularly tossed “vitamin bags” into, in order to keep the “bugs” alive. The biomass was a stratified plastic structure that the “bugs” supposedly clung to, “eating” the waste while allowing reclamated water to pass through. It never worked like advertised, we sued and won.