Monday, June 9, 2008

Our h2o footprint: 112 gallons per day

With 76 of North Carolina's 100 counties still under drought conditions, water use is on everyone's mind. In my city of 276,000 people, significant watering restrictions have been in place since last summer.

According to our recent water bill, our household uses an average of 112 gallons of water each day, or 56 gallons per person. I was a little surprised, until I made a quick mental note of the daily activities for which my husband and I use water. I had a pretty good idea of what we use showering, flushing and washing dishes. But I wasn't sure about the washing machine. I figured maybe 10-15 gallons for a large load. I did a little googling and found these figures: the average washer uses 40 gallons per full load or 55 gallons per full load (click here for additional source). I was floored. I tried to find out some information about our own. I looked on the washer lid and in the owner's manual, but the capacity wasn't listed. Based on info I found online, it appears that our Kenmore extra-capacity model uses 23.1 gallons for a large load. Whew. Not quite as alarming, but still more than I'd guessed.

I've always heard that you save water by doing full loads of laundry. But I never understood why a full large load would use proportionately less water than a full small load. I am terrible at math, but was this true? I obviously have a lot to learn about solids and water displacement. The information I found about our Kenmore 5-setting washing machine supports the conventional wisdom, with the breakdown as follows:
  • Large Load: 23.1 gallons
  • Medium Large Load: 20.5 gallons
  • Medium Load: 17.8 gallons
  • Medium Low Load: 15.2 gallons
  • Low Load: 12.7 gallons
After I solved my little math problem, I started wondering how our average water use stacks up to other households. The American Water Works Association estimates that the daily indoor per capita water use in the typical single family home is 69.3 gallons. If that figure is accurate, then my husband and I are each 19.2 percent below the national average. But the AWWA does not include in its estimate the amount of household water people use outdoors. The City Water Department's assessment of our household's daily average water use includes both indoor and outdoor water consumption. Since we don't have a traditional lawn or a pool, don't pressure wash our house or wash our cars, I figured we'd be even lower.

Since I subscribe to Felder Rushing's mow-what-grows philosophy, we do not have a "lawn" or irrigation or sprinkler system. What isn't a hodgepodge of grasses, clover and weeds on our .16-acre lot is either mulched natural area, established perennial beds with mostly drought-tolerant, low-maintenance plants, or small vegetable patches. I have a few pampered specimens, which include my dahlias and plants in pots that are either newly rooted, too small to be planted in the garden, or awaiting the appropriate permanent location. I estimate that my outdoor water use averages about 20 gallons per day (that estimate is mostly based on how many times I usually fill my 2-gallon watering can for daily outdoor rounds). However, I may be kidding myself, as I do water a little bit with a hand-held hose on the days when we are allowed to do so (four 4-hour increments of time, two days per week).

The City of Raleigh, where I live, estimates that outdoor irrigation accounts for an average of 20 percent of the water use in a typical household. I don't know if this statistic applies to summer only, or averages the amount over the course of a year.

I've regularly read estimates that the average household in America uses upwards of 50 percent of its water consumption on outdoor irrigation. It irks me when articles/organizations don't link their assertions directly to a source or study. For example, this Web article states that
30-60 of urban water is used for watering lawns. The EPA quotes no source for its assertion that "Nationwide, landscape irrigation is estimated to account for almost one-third of all residential water use, totaling more than 7 billion gallons per day." The National Wildlife Federation touts the statistic I usually see regarding per capita water use in a typical household: "The average American uses nearly 100 gallons of water daily for preparing food, bathing, washing clothes and dishes, flushing toilets and watering lawns and gardens." If you start with the AWWA estimate of 69.3 gallons per capita per household for indoor use and tack on outdoor use based on the more-inclusive NWF statistic, then 100 gallons per person per day may be in the ballpark.

I don't want to seem too persnickety about the numbers, as I recognize that environmental advocates (including conservation organizations, water utilities, government agencies, etc.) want to supply us with a general rule of thumb for gaging our impact and trying to mitigate it.

Though I've always identified myself as an environmentalist, I began scrutinizing my water-use habits even more when our state was shriveled by a record-breaking drought and when our city started imposing restrictions. It's undoubtedly responsible for making me an even better steward. I still have water indulgences I could curb. And, as I'm sure many of you are already thinking, household water use is only a small part of the consumption pie. Consumer choices come into play too, such as the amount of water, energy and other resources used to produce food and other consumer goods that we use daily.

When I confirmed that our household water consumption is below the national average, I felt pretty good. Until I quickly reminded myself that "average" doesn't equal "good."
I could preface what I'm about to write with "I don't want to point fingers, but ...." But I won't. That's because I'm unapologetically pointing my fingers: The quest for perfect, sprawling lawns makes me froth at the mouth. Not only because it requires an abominable waste of water, but it is also a source of other evils (introduction of pesticides/herbicides into the environment, burning of fossil fuels to mow and maintain, etc., etc.). If lawn lust is checked, and I hope it soon will be (out of necessity if nothing else), I believe our averages will become something to be more proud of.

I'd love to hear feedback on any surprises you've discovered about your own water consumption, plus links to original sources for popularly quoted statistics. And, of course, corrections to any of my math will be graciously received.

A closing note: I found interesting this study by a Duke University student on how economic status affects household water consumption. Though the study parameters were small, it gave a little validation to my assumption that wealthier people use more water. If undue outdoor lawn watering is as excessive as sources report, then it seemed logical to me to assume that big incomes = large houses = large yards = lush lawns = heavy irrigation.

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