Move over, poop cruise. There's a new poop-related form of transport on the road, and this one is more neat than nasty. A "Bio-Bus" that runs solely on the biomethane gas generated by treated waste (of the food and human variety) is up and running as of this week in the UK, where it's following a Bristol-to-Bath route. The BBC reports that the 40-seat bus can go 186 miles on a single tank of gas; creating that tank requires the equivalent of five people's waste for one year. (It's unclear if that's sewage waste only, or includes a person's food waste, too.) The bus emits 30% less carbon dioxide than a comparable diesel engine would.
GENeco runs Bristol sewage treatment works, which produces the gas through a process known as anaerobic digestion: oxygen-hungry bacteria break down the waste, producing the gas; carbon dioxide is removed and propane is added. Also removed: "impurities" that might make the bus smell like, well, your bathroom. A quote from GENeco's GM, which may have passengers eying each other warily: The bus "is actually powered by people living in the local area, including quite possibly those on the bus itself." The Washington Post notes the news has been predictably greeted with bathroom humor. Among the funniest tweets, compliments of @ant_tweets: "Which line is it? Number Two? Does it have stools instead of seats? Does it run a wee late?" (Read more poop stories.)