Flush with Enthusiasm (But Use Less Water!)

Some questions have occurred to me that have surely occurred to everyone else concerned with the environment: what about all the water we use for toilet flushing?

Are we throwing too much ecological "money" down the loo? Should we implement a "flush tax"?

According to a 1999 report by the American Water Works Association, each person in this country flushes the toilet an average of a little more than 5 times per day. The current U.S. population is nearly 312 million people, so if each of the 312 million individuals flushes five times a day, the number of flushes per day is 1,560,000,000.

That works out to 65,000,000 flushes each hour, or almost 1.1 million flushes per minute in America.

Most modern home toilets use 1.6 gallons of water per flush. That suggests each person uses 8 gallons per day or 2920 gallons per year just for toilet flushing. Of course, the figure might go up or down depending on how many flushes take place outside the home, if the toilets or urinals that are used have a per-flush volume other than the standard 1.6 gallons of water of a home toilet.

I've read that if everyone in the United States flushed the toilet just one fewer time per day, we could save a lake full of water about a mile long, a mile wide, and four feet deep every day.

A rate of four to five toilet flushes per U.S. citizen per day amounts to roughly 2.5 billion gallons of water flushed down the drain daily. That's enough to supply fresh drinking water to the entire population of Chicago for more than three years.

Home indoor water use statistics vary a lot, but seemingly 40% gets flushed down toilets, more than 30% is used in showers and baths, laundry and dishwashing take about 15%, leaks (including toilet leaks) claim 5% or more, which leaves about 10% for everything else.

So if five flushes per person per day were to shrink to four, home water savings would amount to 25%-of-40% of current daily use. 10% of all the water currently being used per day would be saved.

Dual-flush toilets could save even more. These have two selectable flush volumes, 1.6 gal. and 0.8 gal. The latter would typically be used for liquid waste, the former for solid. If four of a person's daily five flushes used the 0.8-gal. amount, each person could save 3.2 gallons per day. That's a reduction from 8 gallons to 4.8 gallons a day, which is a saving of 40%. In terms of total household water use, that comes to 40%-of-40% or 16%.

In earlier decades, most toilets flushed using 3.5 gallons of water, not the 1.6 gallons that are standard today. That was more than twice the waste water per flush!

On a related note, did you know that pharmaceuticals we consume are released through urine? This means after years of our being a society of pill poppers, there’s a vast quantity of pharmaceuticals lurking in our sewage systems. 90% of the pharmaceuticals taken end up in our urine. Scientists are now finding estrogen from birth-control pills, pain medication, and antidepressants in fish.

As for a "flush tax," my home state of Maryland has one! Since 2004, $2.50/mo. has been added to sewer bills (and an equivalent $30 a year fee on septic system owners) to pay for environmental cleanup efforts in the Chesapeake Bay. Read all about it in this article from the Chesapeake Bay Journal.