The term gray water is a reference to human created waste water which contains a relatively low amount of biological material and a low threat of pathogens.

All about gray water at Wikipedia.org

The short description is that gray water is what exits your home from your sink’s drain. Blackwater is the term used to describe what gets flushed down your toilet. Generally speaking, these terms are not used in residential matters because in those facilities gray and black water are treated the same. Those who maintain recreational vehicles are more familiar with the terms because due to the differing requirements of disposing of the two, they are generally maintained in separate compartments.

Fact: The Ohio Renaissance Festival is well aware of the need to collect and properly discard gray water. We have been able to find proof that permits have been issued for gray water holding tanks for a few of its food service buildings. The Funnel Cake Building (APPLICATION NO 05-10351), the Bread Bowl Building (APPLICATION NO 05-10352), the Fruit Building (APPLICATION NO 05-10353) and the Queens Kitchen (APPLICATION NO 05-10354) have had the issue of gray water addressed. It is unclear if appropriate measures were taken, but from information we have obtained from the EPA; the subject of gray water is not new to the Ohio Renaissance Festival.

Fact: The Ohio Renaissance Festival offers several shower stalls to participants and campers at their event. What happens to the gray water generated by these showers is unclear. The floors of the shower stalls do not have drains. Instead, water is simply pools and falls through gaps between wood slots the way rainwater would on a patio deck. It is unclear what happens to this water after it falls beneath the cracks.

If inspectors have problem finding this location, just use this handy picture. The showers are right behind the office on Brimstone road. Please do not make the mistake of thinking these are inside a building, they are constructed against the rear of a preexisting building. I think that is why you seem to be able to see the wiring of that building in the background of the shower stalls.

For reference, the structures to the right of the showers are the offices of ORF Inc. which are located on Brimstone road. They should be very easy to find.

What is clear is that this water often contains laundry detergent, dish washing liquid, and other substances not generally considered biodegradable. To the best of our knowledge, no effort has been made to cause campers and other shower users to restrict their product selection to biodegradable soaps and there exists witnesses to the fact that the showers have been used for washing laundry and cookware without any prohibition on doing so.