crap happensTom Twigg / GristThree hundred million Americans head to the restroom multiple times a day. The amount of sludge produced staggers the mind — 7 million dry tons per year and counting. And it’s not even just crap — it contains residues from everything else we put down the drain, from the detergent in your dishwasher to the chemicals used at the industrial plant down the street.

Can the United States continue to flush all that waste down the drain? Can Western-style sanitary practices be replicated throughout the developing world without breaking the natural water and nutrient cycles? And what if the answer is that each one of us needs to start taking more responsibility for where our crap winds up? It ain’t easy being green as it is, but even the most diehard enviros may not be ready to live under the same roof with a composting toilet.

Journalist Catherine Price, a contributing editor at Popular Science and a 2008 Middlebury Fellow in Environmental Reporting, gives a crap about crap. Over the course of three days, she’ll take Grist readers on a guided tour through the bowels of sewage. So grab some extra toilet paper and get ready for some straight poop on poop.

Day 1

Day 2

Day 3