Guest Commentary

Want to really conserve water? Then consider a composting toilet

The flush toilet may be a hallmark of civilization, but how smart is it to flush away 40 percent of a household's water?

Sure, your excretions disappear at the push of a lever. Water gives an impression of cleanliness. But then there's that orange ring. Contaminated mist released by every flush. Major clogs. Expensive plumbers.

Adding water to excrement only increases the volume of pathogen habitat. Sewers mix the natural output of toilets with residential and commercial poisons. Treatment is complex, employing myriad processes—flotation, flocculation, filtration, centrifugation, anaerobic digestion, evaporation, etcetera—to yield sludge and effluent. Tucson's sludge is used on farmlands. The effluent waters a few golf courses, but much of it gets released into the Santa Cruz River, where it percolates down, carrying whatever pollutants remain into the aquifer.

Theoretically, treatment renders the sludge and effluent harmless. In reality, the treated waste may contain hormones, pesticides, asbestos, petroleum products and even radioactive materials. With scientists continually developing new chemicals, treatment/monitoring procedures can't keep up.

But thanks to a contest sponsored by our Environmental Protection Agency, we do have a friendlier name for "sludge." I liked sca-doo and nutricake, but the EPA chose biosolids. We laugh, but with the new name, the EPA relaxed the rules for agricultural sludge use, reclassifying it as fertilizer. Realistically, no technology can sanitize the polluted output of a public sewer system in this chemo-industrial age. Creative labeling is all we've got.

Unless we switch to composting toilets.

I've used one for 10 years. Mine's a 5-gallon bucket inside a wood box with a hole and toilet seat on the top. Lifting the lid, you see a pretty layer of cloud-pink sawdust, and maybe some wisps of toilet paper sticking up like snowy mountain peaks. Sawdust is the Cadillac of turd coverings: It kills odors faster than flushing and gives the bathroom a piney aroma—way nicer than Glade. The bucket fills in a week or two. Of course, I postpone dumping it as long as possible. But there's no room, literally, for procrastination.

I dump my bucket at night, like a criminal, because my elderly neighbor sometimes sits by the fence near my two compost bins. She's nearly blind, but I can't assume her sense of smell has deteriorated. The bins look like Darth Vader helmets, and I am about to make a stink, briefly, like something from the dark side. I take the cap off the active bin and lift the bucket. It's heavy, though lighter than the 5 gallons of paint it once held. I tip it. The slop slides in.

It reeks. But when I throw sawdust over the mound inside, the smell is nearly canceled. I rinse the bucket, throw that liquid in and cover everything with more sawdust, sealing odor in and flies out. The lid's insurance. I snap it on.

It's a 10-minute task, with mere seconds of natural, authentic stench. Compared to the skanky times I've had with flushers, it's not so bad. I'm sewer-free. My water bill is low. Best of all, when the active bin is full, I know my other bin is done stewing. The pathogens in the muck I dumped 10 months ago—bacteria, viruses, worms, protozoa—are dead. These could cause sickness, diarrhea, even death, but outside their host, they don't survive long.

Different microorganisms break down the mix, depending on temperature. Composting slows down in colder climates, but black bins in this desert really cook.

I open the door at the bottom of my fully "baked" bin. Loose, dark soil spills out, smelling like the damp, black dirt found under leaves in the forest. The transformation is more dramatic than water to wine: miraculous.

When I rake the compost over the pale dirt in my yard, the patch exudes fertility. I plant veggies. Whatever passes through my gut completes the natural cycle that's all but forgotten in this world of germy bowls pretending to be fine porcelain.

Sadly, if I live to be 80, the water I save would barely supply a golf course for one day. And bucket toilets won't become popular anytime soon. But commercially made composters look a lot like the flushers and require no dumping; you get a drawer of finished compost. And Pima County's Department of Environmental Quality approves of those, whereas my "cartage system" isn't to code. That's why I've omitted my name on this article. Nevertheless, I'm proud to be among those who don't add water.