If you’ve tried to explain to customers how many gallons per day of water they consume and were met with a disbelieving stare, then the results of a recent water usage survey will come as no surprise to you.

According to the report, Perceptions of Water Use, published by the National Academy of Sciences, most Americans use twice as much water as they think performing household tasks. The study’s author, Shahzeen Attari, an assistant professor in the Department of Public and Environmental Affairs at Indiana University, states, “In general, people tend to underestimate water [use] by a large magnitude.’’

A cross-section of 1,020 U.S. residents was surveyed for the study aimed at finding out what people know about their water-consumption habits. The study was based on a concern about dwindling water supplies and the need to conserve the vital resource. Onsite installers could look at the results as a validation of their efforts to educate homeowners about wasting water and how that impacts the life of an onsite system.

TIME TO TEACH

The study brought to light some interesting consumer trends and challenges moving forward but came to an optimistic conclusion: “Well-designed efforts to improve public understanding of household water use could pay large dividends for behavioral adaptation to temporary or long-term decreases in availability of fresh water,’’ the author states.

The online survey turned up a few interesting facts:

Estimates are way off for high-usage activities.

On average, those surveyed underestimated water usage for a variety of typical household activities. For example, participants thought a standard clothes washer used 14 gallons of water compared to the actual 34 gallons for typical usage. The differences between perceived and actual usage grew when looking at high-use activities, such as running a garden hose or keeping a hot tub full.

According to the study, the best available U.S. Environmental Protection Agency (EPA) data on water usage and appliances is 14 years old, but it remains relevant. Here’s how it breaks down overall water usage in the home:

• Toilet: 26.7 percent
• Clothes washer: 21.7 percent
• Shower: 16.8 percent
• Faucet:15.7 percent
• Leaks: 13.7 percent
• Other: 5.3 percent

People think changing habits rather than switching to water-saving devices is the greater solution.

Respondents believe curtailing water use during certain activities makes the biggest impact on conservation. When asked about the single most effective thing they could do to cut down on water usage, 42.6 percent answered taking shorter showers, by far the biggest response. Others included turning off water when doing other activities [not brushing teeth]; turning off water when brushing teeth; doing less laundry or full loads of laundry; and watering the lawn less often.

Shorter showers and lawn watering might be high on the list because people associate those activities erroneously with extreme water use. Because flushing a toilet only takes a few seconds, they might not think of its greater impact on water usage, the study concludes.

The responses conflict with EPA recommendations for slowing the flow of water through the house. Among the least-mentioned conservation actions mentioned by respondents were “buying water-efficient appliances and fixtures” along with “water-efficient toilet” and “flushing less.” According to the study, the EPA estimates that retrofitting toilets for efficiency would cause the greatest savings (71 percent) in indoor household water use. The upfront cost associated with replacing inefficient fixtures may be one reason respondents mention that solution less frequently, the study speculates.

Education efforts should target women and young people first.

If you’re a parent always harping on teenagers for their long showers, this conclusion makes a lot of sense. The median age of those taking the survey was 30 years old, skewing younger than the U.S. median age of 37.2 years. A few more men (51.6 percent) than women took the survey. The study determined that older and male participants were more accurate in their perceptions of water usage.

DRAW YOUR OWN CONCLUSIONS

None of this is surprising (with the possible exception that men showed a more realistic perception of water usage). The study shows that when water is plentiful and inexpensive, and overuse doesn’t cause significant issues, people are not going to pay much attention to it.

It’s the same thing we’ve experienced with gasoline. Regular was 50 cents per gallon when I was in high school, so it didn’t hurt much when I pulled into the pump in my gas-guzzling ’68 Chevy Impala with its rumbling 327 V8. But today, Americans look at fuel consumption in a different way. With skyrocketing prices, they have to.

Attari’s report cited another study estimating 13.2 gallons of clean water are required per person, per day for human needs, but that the average American was using 98 gallons of water per day in 2005. And 70 percent was used indoors. Clearly there’s a disconnect between expectations and reality, and we’re needlessly pouring a lot of water down the drain and loading drainfields.

So, like you’ve known for as long as you’ve been designing or installing septic systems, most homeowners need a little education about using water efficiently – not just to conserve the resource, but to keep their private wastewater systems working properly. Anything you can do to further that effort helps the environment, saves your customers worry and repairs down the road, and enhances your reputation as a wastewater professional. Class is in session.