Tuesday, June 30, 2009

Toilet Water

This next post was precipitated out of a dialogue that I had on an internet forum where we were discussing local water rates. The thread wandered into a seemingly simple question about toilet replacement programs for municipal water conservation. So I thought I’d expand a bit on my response here.

O.K. Get your number-crunching tinfoil hats of folks, because I’m going to throw a lot of statistics at you right off the bat. In the U.S. we consume about 410 billion gallons of water per day (Bgal/day). That turns out to be around 12 times the volume of Lake Superior annually. About 16% of the water that we use is salt water, so that leaves ~345 Bgal/day of fresh water that is consumed. About 70-75% (242-259 Bgal/day) of that water is taken for agricultural uses, mostly irrigation. Over 50% of the water that is used for agricultural irrigation is lost due to evaporation (76 Bgal/day). Around 15-20% (52-69 Bgal/day) of the remainder of our water supply is used in industrial processes such as power generation, mining, etc. That leaves ~10% (35 Bgal/day) of our total freshwater consumption in the U.S. for municipal water use. Home use accounts for about 65% (23 Bgal/day) of that, with businesses sucking up the rest.

Fifty-eight percent (13 Bgal/day) of the fresh water used for homes is used outdoors for lawns, gardening, pools, etc. That leaves 42% (10 Bgal/day) for indoor uses. Toilets account for 31% (3.1 Bgal/day) of indoor usage. That works out to be somewhere around 1,100 billion gallons of horrifyingly filthy water that gets flushed per year, or a volume roughly equivalent to the total volume of Lake Powell on an average year. Kind if gives the term “fly fishing for browns” a whole new meaning. So, since thunder mugs are the biggest indoor users of water it seems logical that replacing inefficient commodes with high-efficiency thrones should be a great idea. Well, maybe on the surface, anyway.

Let’s say a city wants to engage in a pilot toilet exchange program. If they wanted to replace 1000 chamber pots they would need to set aside ~$200k of taxpayer funds. A program of that size would only be able to service 500 average households with 2 crappers each. In the end {…ahem…} the program would save about 131 liters of water per day per household (assuming everyone makes all of their “deposits” at home). That’s about 24 million liters (6.3 million gal) of water annually with a return on investment of about a penny per liter saved. Average municipal water rates are about $.0025 per gallon or $.00066 per liter in the U.S. (Choke that one down, all of you bottled water drinkers out there. I’m coming after you later.) At those rates, even our modestly-sized exchange program will take over 15 years to pay itself back. Doesn’t seem like too great of an investment. Plus, it places 1000 non-recyclable dunnies in the landfill – not that I think that actually matters, but I’m sure some of you do.

Maybe I’m just looking at this the wrong way. How about trying to tackle it from another angle? Saving 6.3 million gallons of water for 500 households seems like a lot of water. Let’s compare that amount to something more tangible. It is estimated that it takes 2,500 gallons of water to get each pound of beef to your dinner table. This means that the water that goes into raising and processing a 1,000 pound steer would be enough to float a destroyer. The 6.3 million gallons of water that we saved by switching out our porcelain gods is less water than it takes to bring three gross-ass stinking cows to market. That’s right, three. Hmm…three less cows or the time, effort, cost and landfill space for 1000 loo’s? I’d gladly give up beef (if I ate it) in order to keep a water-gulping jet flush shitter that gives me a hickey the size of my arse every time I drop the deuce. Well, so far our privy exchange program doesn’t look too good from this angle, either. Crap. How about one more try? O.K., it would take over 45 years of water-saving toiletry to equal the water that evaporates from agricultural irrigation in one year. Oh, dear. This one just doesn’t pass the smell test.

I guess this analysis shouldn’t be too surprising. Of course the government isn’t going to recommend that we cut down on eating beef, and it isn’t just because the cattle industry is evil. On one hand you have a potty replacement program and on the other hand you have educated consumerism. See the difference? One says consume more (buy more toilets) while the other say consume less (eat less beef). I don’t want to deviate too far into food politics here, but there has never been an instance when American consumers have been encouraged to consume less food. For example, the message of “Eat less fat” becomes “Consume more healthy fats.” So, in this case we’re led down a path that makes us feel that not only is it the municipalities’ responsibility to conserve water rather than placing the onus squarely upon the shoulders of agriculture, but also that it is the fault of homeowners since we use inefficient appliances.

It stands to reason that since most of our water is wasted agriculturally, that most of the conservation, and, therefore, the most good can come from encouraging and subsidizing better farming practices. The agricultural sector looses 3.3 times more water than the entire municipal system uses annually. So, even if we were to cut out all of our municipal water usage, clean ourselves and our clothes with soda pop, and irrigate our lawns and fill our pools with beer it would hardly matter at all in the long run. I mean taking it a step further, it seems logical to me that since 70% of all of the grain grown in the U.S. goes to feed livestock, and most of the water losses in the U.S. are due to irrigation evaporation, that maybe (just maybe) we could do better by not eating so many effing cows? Just a thought. If that seems like too foreign of a concept, then how about losing the crappy bluegrass lawns that people insist upon growing in the desert? As I said 58% of municipal home water use goes to continually water something that isn't supposed to grow in areas where irrigation is necessary. Incidentally, the bluegrass lawns that everybody loves so much were originally developed for cattle grazing. God, I hate cows.

Getting back to the latrine exchange programs to wrap this up, if municipalities were to use that $400 per household as a credit to encourage the installation of a gray water recycling system in every household we would actually save 2,500,000,000,000 gallons of water annually nationwide (assuming all of the reclaimed water gets used outdoors). Gray water recycling systems essentially divert and filter all of the water that doesn’t come from your throne room and use it for outdoor irrigation. It would take our silly nationwide stool replacement program around 4 years to save that much water (assuming every toilet in the country gets changed). I’m not shitting you, honest.

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