Interesting topic. I am a one-person studio potter who works out of a 1,000 square foot space in my house that is designed the studio around sustainability. I fire electric. All my failures (bisque or glazed) get broken up using a box and a tamper used for asphalt work and is used behind retaining walls, in steps and along paths around the house. All glaze water uses to wash bottoms, etc., goes into a 5 gal bucket where it settles out and the clear water either goes down the drain or is cycled through my glaze spray booth. The glaze is concentrated and test fired with each glaze firing. If it turns out well, it becomes Slop I, Slop II, etc. If, like a good wine it is not ready yet, more goes in. Most of the time it comes out a bronze color used on outside of functional pots.
Clay slop goes down a separate sink made from a laundry sink and into a 30 gal tank where it settles. The clear liquid then goes outside into a 125 gal tank that also captures my air conditioning condensate and then is used to water plants in the yard (no veggies though). All clay is recycled in a small pug mill. The objective is to recover 100 percent of the clay, and so far, after 4 years, I am succeeding. Over the years, I have reformulated my glazes to get rid of heavy metals as oxides.
I make functional ware. My greenware accumulates so I have all kinds of sizes to as tightly pack my electric kilns as possible. The most product for the firing. Glaze firing is the same, every shelf full with no more than a quarter inch spacing between pieces.
I regularly (3-4 times a week) mop and wipe down the clay dust, this water is recycled as well.
The spray booth, made from two laundry tubes, on stacked inverted on another and an opening cut out, uses a circulating pump through a copper pipe with holes in it that creates a cascade of water to trap the spray and is recirculated. At the end of the glazing, this goes into the glaze settling bucket.
As a potter of one, I would like to here from other small operations.