What do you do when nature calls and you're climbing Everest? Digging a hole in the snow is out of the question, although this does happen at some of the camps, explains former climber and engineer, Garry Porter.Nathaniel Janega/ Mount Everest Biogas Project
Higher up the mountain where facilities are scarce, climbers are encouraged to deposit their bodily waste in disposable bags and bring it back down with them, explains adventurer Ben Fogle, pictured alongside a makeshift toilet in a tent.
But at base camp, Nepalese authorities have installed portable toilets in the form of blue barrels. According to Fogle, the rule at base camp is to not mix urine with feces. The blue barrels are solely for solid human waste.
Local porters working on Everest lug the barrels down from base camp to Gorak Shep, a frozen lakebed 17,000 feet above sea level.Nathaniel Janega/ Mount Everest Biogas Project
Here the waste is dumped in open pits.Mount Everest Biogas Project
But poop does not decompose at altitude in sub-zero temperatures. Instead it dries up and shrivels, releasing harmful gases, explains Porter.Mount Everest Biogas Project
It can also potentially leak into the water supply system, he adds. Mount Everest Biogas Project
To address the issue, Porter began working on a biogas digester that can operate in Everest's harsh climate.Joseph Swain/Mount Everest Biogas Project
Once operational, the digester will convert human waste to methane gas, which can be used for cooking or lighting, and effluent that can potentially be used as fertilizer for crops.Mount Everest Biogas Project
But the living microorganisms in the digester need to be kept warm to break the waste down. Porter and his team plan to use solar power to heat the digester.Joseph Swain/Mount Everest Biogas Project
Researchers from Seattle and Kathmandu University have conducted several tests to see if the technology works. Porter estimates the first digester will cost around $500,000 to construct.Mount Everest Biogas Project