Oh I don't know, I lost mine. I'll see if I can find out.
Actually, textile fabric doesn't seem to work out too good in this area. We've had far, far better luck with scraping away topsoil, getting down to an undisturbed base, laying big rock, little rock and limestone screenings, and having a drainage path.
Our sacrifice areas are really sloped. We drag and scrape and level them with the same tool we use in the arena, to prevent erosion paths from starting, and we periodically add limestone to loafing areas and keep them level. There are times in the winter when we actually plough or snow blow the sacrifice areas, too.
We've got some very unusual conditions here for sure - very severe melts and heavy snows, but overall, I'm seeing a general trend away from membranes and textile layers in riding areas.
About 10 yrs ago, everyone around here was getting them. There were definitely mistakes made - one gal I knew went around and told EVERYONE to put hog's fuel as their top surface. It is horrific around here. It breaks down here in about one year to black muck glop and clogs the membrane.
Even people who didn't go with hogs fuel on top, though, I saw people try several different types of top layers, different kinds of sand, ALL ultimately clogging the membrane. And to my complete horror and shock, LOL, I've now had more than one arena builder tell me, 'all membrane areas eventually fail'.
And well the truth of it really is that all layered drainage systems eventually fail, just how eventually is eventually.
My county extension office is still encouraging geogrid and heavier stabilizing materials though, especially in loafing areas for cattle, etc.
I'm probably going to be a pill and say that any good rural excavator should be able to do basically what the USDF brochure said.