Dear Umbra,

I’m attempting to “green” my home, room by room. I’ve heard of low-flow toilets, but someone just told me about composting toilets. Do they smell bad? Will my grandmother use it or ask for an outhouse? Thanks for your wisdom!

Providence, R.I.

Dearest Moira,

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Excellent, manageable room-by-room plan.

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What in tarnation?!

Composting toilets are basically the technology we should have adopted instead of the water closet. Although there’s a wide range of models, all of them compost human waste into a humus-like end product that can go back into the earth whence it came. Essentially a compost pile within the home. These toilets either contain the waste — oh, I might as well use the cute term “humanure” — just below the bowl or send it down a chute to a central holding container. The odors are vented outside. Water use is either low or none, electricity use is low or none, smell should be zero, conversational value quite high. Unfortunately, price can also be quite high, ranging from $1,000 to $5,000.

The smelliness and effectiveness of the toilet will depend on your ability to follow instructions. Do you remember our past discussions on anaerobic and aerobic composting? Aerobic composting integrates oxygen and moisture, and the microorganisms that thrive in this rotating, air-rich environment reduce smell, process raw materials quickly, and leave you an excellent final product, no matter what you are composting. It is essential that humanure composting use an aerobic process if it is to be anything more than an outhouse. Your toilet may require adding wood shavings or another “accelerator,” and turning a handle or pressing a button. It certainly will require removing the humus, but hopefully not more than once or twice a year.

The tricky thing is that you become responsible for your body’s waste, from start to finish. The EPA has put out a little primer [PDF] listing the pros and cons of composting toilets. The cons made me giggle, because they all boil down to: It’s POOP. Human waste is stinky, carries dangerous pathogens, and is socially unacceptable — dealing directly with adult poop is foreign to most contemporary Americans. Although composting toilets are supposed to remove pathogens, and humanure has a long tradition as a soil amendment — it even has a special superhero name, Night Soil — all officials advise caution in handling what could basically be a big pile of disease. Check your local solid-waste regulations for more guidance.

If you are intrigued but worried about grandma and other visitors, the scourge of being weird, or the strangeness of such a novel concept, perhaps you could find a local compost toilet to visit. The manufacturers can tell you who sells their product locally, and those dealers should be able to send you somewhere to view this paragon of common sense.