Plumbing fixtures are a nearly invisible part of our daily landscape. Try to remember the last time you walked into an office building or airport bathroom. Chances are, the toilet you used flushed automatically, the faucet turned on once it detected motion beneath the spigot, and an electric air dryer activated at your approach.

But maybe your overzealous toilet flushed more than once—as you were entering or exiting the stall perhaps. Maybe the faucet began to spew water at full stream while you were moving your hands toward the soap dispenser, which then dolloped a second portion of suds you didn’t need. Perhaps the blow-dryer stayed on long after you had dried your hands. Or maybe (and this happens more frequently that you might think) the toilet and sink weren’t automatic at all—but you’d grown so used to computerized bathrooms that you forgot to turn off the faucet entirely.

When they first appeared in the 1990s, automatic-flush toilets and motion-sensor faucets were marketed as hygienic, no-touch alternatives to conventional commode fixtures. These days, they’re also marketed as essential water-saving tools in states like California, where multiyear droughts have become a way of life.

But some of these fixtures may end up wasting the very resources they are designed to conserve: Sensor-flush plumbing, automated light fixtures, and motion-triggered faucets often use more water and energy than manual alternatives (good old-fashioned faucets, light switches, and recycled-material paper towels).

The EPA estimates that there are over 25 million self-flushing (a.k.a. “flushometer”) toilets installed in restrooms throughout the United States. Many of the older models still in service use 3.5 gallons or more per flush—much more than the current federal standard of 1.6 gallons. But even newer, more-water-efficient toilets have a reputation for “phantom flushing” (that is, a flush in response to motion in the stall, even when nobody’s doing their business inside it).

Motion-detecting sensors alone provide no additional water-efficiency benefits, says representative Veronica Blette, chief of the EPA’s WaterSense branch. In fact, they can increase water use if they aren’t properly operated and maintained. Several years ago, Veritec Consulting Inc. and Koeller and Company conducted an extensive fixture replacement study in a major commercial office building: They replaced manually activated faucets and flush valves with sensor-activated units and measured the results over a two-year period. The study showed that the replacement of manually operated lavatory faucets with sensor-activated faucets resulted in a 30 percent increase in water consumption.

Consider that the most common sensor type, infrared, emits light outward. When movement comes within the sensor’s range, water flow is automatically started—even if your hands aren’t anywhere near the faucet. And many experts maintain that auto-sensor faucets are actually less sanitary than their manual counterparts. Researchers at Johns Hopkins Hospital conducted an eye-opening study on the bacterial growth within two different kinds of taps—hands-free, automatic faucets and manual spigots with handles. About half of the water samples from the electronic faucets tested positive for legionella and other bacteria, while only 15  percent of the samples from the manual faucets did. The researchers weren’t exactly sure why this was the case but speculated that the more-complex internal workings of the automatic faucets might be trapping bacteria and providing it with a hospitable environment to grow. 

Consumers and manufacturers can be enchanted by plumbing devices that, while tricked-out in terms of technology, fail to improve on what they’re replacing. “Take waterless urinals, all the rage a few years ago,” says Terence O'Brien, deputy director for the Plumbing Foundation. “It was such a new technology that no one was sure of the viability or longevity. But they aren’t really a green product.” Even though these fixtures used no water, they relied on chemicals in place of a flush, making them costly to clean and maintain. 

So what fixtures should people use in their home and commercial lavatories? Blette suggests looking for the EPA’s WaterSense label or Energy Star certification on products, which are certified to use at least 20 percent less water and perform as well as or better than standard models. While traditional spigots with handles are liable to waste water due to leaks, consider installing a manually operated faucet that features a push-button instead of a sensor. These are metering faucets: They monitor water flow at a pre-set temperature and turn off after approximately 15 seconds.

From high-efficiency shower heads to toilet fill-cycle diverters, a range of tested alternatives are available. Faucet Magazine produces a guide to the best bathroom and commercial faucets, detailing their water-usage efficiency, temperature control, and price with a handy comparison chart (there are even solar-powered faucets featured). Consumer Reports ranks water-saving toilets based on performance and cost in its cleverly titled “Game of Thrones” review, while Energy Star highlights products in a “Most Efficient in 2017” roundup.

Despite the availability of better technologies, many older models remain in use because of the high price of upgrading. It can easily cost hundreds of dollars to replace a single toilet, and the incentives for green initiatives—beyond water savings and an unstated carbon footprint reduction—are still remarkably low.

Your utility company might offer rebates when you buy new water-saving shower heads, faucets, or toilets. Consumers can search Energy Star’s Rebate Finder to find incentives in their area. So much depends on location, however: A zip code search of the New York metropolitan area revealed zero rebate offers, while a San Fernando Valley search turned up 11 various programs.

The fact is, municipalities and manufacturers need to focus on energy standards rather than on promoting gimmicky, untested products. News outlets, consumers, and experts all seem to agree that more research needs to be done before we automatically reach for automatic. “If you simply increase standards instead of bringing in unknown new technology,” O’Brien points out, “that may be a better way to improve conservation overall.”