Are Automatic Toilets Still Wasting Water?

toilet, flush
Automatic-flush toilets may no longer be the water wasters they once were as more eco-friendly products are performance-tested to meet the EPA's gold standard. Ullstein Bild/Getty Images

In this world, nothing is certain except death and taxes — and the unnecessary premature flush of an automatic toilet.

If you've ever set foot in a public restroom stall and immediately been greeted with the jarring sound of a mechanized deluge of water, you're not alone. According to the Environmental Protection Agency (EPA), there are about 27 million self-flushing toilets (otherwise known as automatic-flushing toilets, commercial toilets or flushometer-valve toilets) in the United States alone, and many of these motion sensor-equipped machines exhibit the disconcerting behavior known as "phantom flushing."


Sometimes referred to as "ghost flushing," phantom flushing is the phenomenon of a toilet's water refill valve switching on after a period of inactivity. This can happen on old-school manual-flush toilets, too, due to deterioration. But when it comes to automatic-flush toilets, the occurrence seems so common it's almost expected until, of course, you need the flush and then the motion sensor seems to fail you in every way.

So why did society decide to move toward an automated flushing system in the first place, and has the move helped or hurt attempts to save water?


Why We Went Automatic

The trend toward automatic-flush toilets took off in the 1990s. Touch-free bathroom fixtures were marketed as more hygienic options for high-traffic areas like airports, and eventually they also were touted as water-saving staples in drought-affected states like California.

But according to environmental advocates, the original automatic-flush products did nothing to serve the environment. In fact, the older models were suspected of causing more harm than good. The EPA even claimed that about 26 percent (or 7 million) of the 27 million automatic-flush toilets around the country flushed at volumes higher than the federal standard, which is 1.6 gallons per flush (gpf), or 6 liters per flush (lpf), and that some flushed as much as 3.0 to 7.0 gpf (11 to 26 lpf).


"When compared to a manual-flush toilet, there is no way that 'automatic' toilets save water, because what can be better than a single flush per use?" says Yorba Linda-based engineer and water efficiency expert, John Koeller. "The typical automatic flush toilets have the propensity to double-flush, triple-flush or even worse due to being out of adjustment, poorly installed or poorly maintained. So, there is no water conservation benefit with 'automatic' flush toilets, but there is the potential for water waste."

To quantify just how much water was being wasted, Koeller and his Toronto-based colleague Bill Gauley developed something called the Maximum Performance (MaP) Testing protocol to provide an independent assessment of toilet water efficiency. Armed with the MaP test, Koeller and Gauley conducted one of the only studies to date examining water use by automatic-flush toilets as compared to manual-flush.

The pair found in their 2010 research that compared to manual-flush toilets, automatic-flush toilets increased water consumption by 54 percent thanks to phantom flushing.

But according to plumbers in the field, automatic flushing technology has vastly improved in the eight or so years since Koeller's research.


The Flush of the Future

"Automatic toilets do in fact save water," says Ryan Miner, owner of Bay Area-based Miner Plumbing. "They save water because people have a tendency to think that if you hold the handle down longer, it will have more 'flushing power'; well, it's more water, but it certainly isn't more flushing power." Miner says that while older models weren't up to task, newer models, particularly from the Japanese brand TOTO, are in fact eco-friendlier.

And although some have blamed years of phantom flushing from older models on poor installation and maintenance, experts in the field say substandard technology and poor training were more likely the culprit. In 2015, Mark Malatesta, a product compliance engineer at toilet maker American Standard, told the Guardian, "It's usually building maintenance or plumbers installing them, and a lot of times there's just a lack of knowledge about how the products work," he said. "Once installed properly, you should be good to go." (Forgive us for that.)


But Miner says he and his colleagues weren't prepared to tackle the automatic-flush models when they first emerged. "Plumbers weren't given a heads-up on the new technology," he says. "This product was slapped on our knees, and we were left to figure it out and make it work. That being said, it's really tough to mess it up and make it so that the toilet is phantom flushing. The blame is really on the product. It was new, and it was faulty." Miner says installation should always be taken care of by a professional, although newer automatic models are a lot more user-friendly.

Koeller agrees that phantom flushing shouldn't be pinned on plumbers. "For the skilled plumber, I would say it's not tricky," he says of installation. "That is not the only reason for phantom flushes. Ignored maintenance, deferred maintenance or poor maintenance could all lead to faulty performance of the flush sensor used to trigger a flush. In addition, many of these so-called 'automatic' flush toilets are installed in toilet rooms subject to abuse by the public or others. High-usage toilets need to be monitored for performance by the maintenance personnel and fixed when needed; this does not always occur in many installations."

Miner also earlier alluded to another reason automatic-flushing toilets may no longer be the major water wasters they once were: Brands like TOTO are partnering with the EPA to create eco-friendly products that are performance-tested and validated by various agencies to meet the EPA's gold standard. High-efficiency toilets that meet the EPA's stringent guidelines get a WaterSense label, letting customers know they're purchasing a product that's expert-approved and much less wasteful. WaterSense flush at 1.28 gpf (4.84 lpf), which is 20 percent less water than the federal standard, and also have a minimum flush volume of 1.0 gpf (3.78 lpf) to guarantee plumbing systems have adequate flow for proper functioning.

And the EPA says there's more to save than just water when purchasing a WaterSense product: They estimate that a 10-story office building with 1,000 occupants could save 1.2 million gallons (4.54 million liters) of water and more than $10,000 in water costs by replacing old automatic-flush toilets with WaterSense labeled models. "If commercial facilities nationwide replaced all of their older, inefficient flushometer-valve toilets with WaterSense labeled models," the agency writes in a statement, "we could save nearly 39 billion gallons (148 billion liters) of water per year. That's equivalent to nearly one full day's flow of water over Niagara Falls!"

So if you're planning to purchase your own automatic-flushing toilet at home, be sure you look for the most up-to-date products out there. And if you're walking into an out-of-date public restroom ... beware of phantoms.