Peekaboo Vaults to New Heights!

Buildings and Utilities Supervisor Dale Pollock in front of new Peekaboo Vault Toilet

NPS/Jim Hall

This project was possible thanks to the generous support of the Bryce Canyon Natural History Association. This project was completed in May of 2021.

Peekaboo Loop Trail is the one of the most popular trails in Bryce Canyon National Park. According to trail counter data collected in 2016, over 28,000 visitors used this trail during the peak season (May-October). If these numbers are adjusted for the current level of visitation in the park, over 35,000 visitors hiked this trail in 2019.

The Peekaboo Restroom located on the Peekaboo Trail near the horse corral has been a source of maintenance headaches for a period of time at Bryce Canyon National Park. The facility began its service as a solar composting vault toilet. Vault toilets are a type of toilets that don’t use water or flushing, and they store waste in a large vault container located underground. A typical vault toilet will consist of two parts, namely the underground vault and the upper part which looks like a booth.

First day of emptying the vault.

NPS/Jim Hall

The vault in the ground can have a capacity of anything from 1,000 to 13,000 gallons. Typically, vaults can be emptied when the vault is near full; however due to Peekaboo’s location, at the bottom of a canyon, emptying the storage vessel was difficult and transporting the material was not an easy task.

Controlling odors from a vault toilet can be problematic, it depends on a few external factors to get it right. First, the vent has to be taller than the roof of the toilet booth--Check, we had that. You also need the wind to carry away the stench or else it’ll simply cloud around the toilet. We had the wind, but we also had a 12” hole in each bathroom that was connected directly to a vessel full of you know what and it didn’t smell like roses, to say the least.

As with most engineering projects, the desired result is stated and then the first step is typically research. Various types of toilets were researched—everything from incinerating to various types of composting. Since the existing composting toilet seemed to have some built-in issues with combining the two waste streams, we searched for a technology that would potentially separate them.

Thankfully, someone had thought about that also. The general premise is to divert the urine to a leach field and then to deal with the solids. There are a couple of solutions for solids: one was to let bugs consume the piles and the other was to capture the solids in trash bags so that they could be removed from the site. The latter method, available through the Toilet Tech toilet, was chosen as the path forward to base the reconfiguration of the bathroom on.

Accessing and cleaning the vault toilet chamber.

NPS/Jim Hall

The initial step to the conversion was to remove the existing thrones and clean out the holding vessel. It was not going to be a pleasant job.

In the picture at right, you can see the small white cover with the three holes in it, this was a 1’ x 3’ hatch that allowed you access to the contents. As can be seen, there was not a lot of room to work in and soon I would know just how hard removing the contents was. I suited up with my Tyvek suit, rubber gloves, and safety glasses and climbed down in.

To retrieve the contents from the vessel, one needed to use the rake with the red handle, as seen in the picture, chop at the solids and then pull onto a shovel, lift the shovel out through the small opening and then dump the shovel load into a plastic bag. Not impossible, but certainly it was not the easiest of tasks. After removing approximately 750 lbs. in this manner, I brought down an electric saw and chopped the front partially off which then allowed easier access as can be seen in the pictures at right.

Needless to say, as evidenced by the picture, there was a bit more in the vessel than had been described, in fact, there was about 2,800 lbs. of vintage human waste. Luckily, the thought of so much was worse than the actual smell. The pictures at right present a small timeline of the removal of poo.

While the vessel was being emptied out, another crew worked on installing the leach field where the “diverted” urine would flow to. The team used a trencher, a pickaxe, and a few shovels to dig the 30-foot long, 30” deep trench to put the French drain in.

The French drain was surrounded by Styrofoam pieces to increase the surface area of drainage. A leach field using a conventional French drain would have been double or triple the size. Science is awesome! The ground pipe was covered up and after a few days, it looked like it always did, a sandy trail.

Once the vessel was emptied out, the removal of the old thrones and the installation of the new ones happened. New linoleum was installed after the new toilets were fitted through the walls. The lever on the side of the toilet is what moves the conveyor belt for the solids.

The French Drain and portion of the 30 foot long trench.

NPS/Jim Hall

The construction of the new access lid also began. The concept was pretty simple: make it easy to access so that working on it would not be a chore. The maintenance crew completed the concept in spectacular fashion.

The new restroom has been in service for a complete season and the resulting facility has exceeded all expectations. There is little to nearly no smell, although it is planned to install a small fan using the photovoltaic system to power it. The fan will serve two purposes, to move more dry air over the solids in the trash cans and to move any minor odors up the stack and away from visitors.

The maintenance for the restroom has decreased as visitors no longer try to dispose of trash in the restroom, and the previous biannual removal of the poo/pee mix is no longer needed.

The two bags held by Dale Pollock, Supervisor of the Building and Utilities team at the top of this article weigh less than 5 lbs a piece, and all that is needed is to wear a pair of gloves.

All work was performed by park staff, the resulting product is excellent, and the sense of ownership is apparent when the facility is used by visitors as they often state that the restroom is so clean and doesn’t smell like a lot of park’s vault toilets. Victories come in all shapes and sizes.

Removing the old thrones and the installation of the new ones along with new linoleum. See the small foot lever on the side of the toilet.

NPS/Jim Hall

Our Maintenance crew constructed a new access lid for the solid waste storage unit. Waste moves by foot-powered conveyer belt and is then removed by custodial staff.

NPS/Jim Hall

Thanks to the park's Chief, Engineer/Project Manager Jim Hall, P.E. for submitting this article. Questions for Jim? Send him an e-mail.