In the section of the NPS’s Noncommercial River Trip Regulations entitled “Human Waste Carry-Out Method” (Page 14) the NPS asserts: “It is easy to contain about 50 uses in a container measuring 2,000 cubic inches.” By our calculations this equates to 40 cubic inches per use. Wow! That’s one massive bowel movement. Our experience is that half that amount is adequate. But when you’re on the Grand you have to play by the NPS rules, so our calculations for the size of our groovers assume 40 cubic inches per use. So, for a 12 day trip on the Grand the NPS says you need 480 cubic inches of space for your PHWM system. We considered two different ways to provide 480 cubic inches for human waste: Pelican cases or PVC pipe, and our experience is that the PVC pipe is the superior method.
There are several options for wall thickness in PVC, and for this purpose the thinner the better. The attached calculations assume SCH 40 PVC, which is generally available at building supply stores. It’s the green PVC pipe at Lowes or Home Depot, but Woody found at a local supplier some thinner PVC used for sewer pipe. You’ll want to use 6″ PVC, which fits well in the front of the kayak, and the pipe needs to about 16″ to get you the required volume. A solid end cap is glued on one end of the pipe, and on the other is glued a female threaded end cap with a threaded plug.
You’ll want to manufacture some sort of “groover wrench” to unscrew the threaded plug. The plug has a square nut on it, so we cut a piece of 1/4 inch plastic sheet as a handle with a matching square hole to serve as a wrench. Another important innovation in PHWM system is the foam plug. This is a circular piece of minicell about an inch thick that fits inside the groover and separates the HW from toilet paper, wipes, etc.
The container fits well in the front of the XP10 by cutting an insert slot in the front wall of the boat. Punch a couple of cam straps through the foam that will secure the groover in the wall of the kayak. The groover is then sitting between your feet while you’re paddling, and you don’t even know it’s there. –Boyce–
The groover is a necessary piece of equipment for any Grand Canyon Trip. Here is a little video with Grand Canyon veteran Will Lyons explaining the beauty of…well watch the video and see for yourself.
This article is reprinted with permission and some minor editing from Amongst It’s now-discontinued website, kayakcamping.amongstit.com. The website is no longer available, but you can view some of their articles here, and you can browse the entire site using archive.org. Boyce Greer contributed to both the website and the underlying Grand Canyon trips and ideas and he continues to be an inspiration to all of us. “Trip of a lifetime every year.”