Everyone is preoccupied with oil shortages these days. But the building industry's eyes are already on the next scarce natural resource: water. While the U.S. population nearly doubled between 1950 and 2000, the demand for water more than tripled, putting pressure on both water supplies and an aging distribution system. That's true not just in arid regions, but across the map. A recent government survey showed that at least 36 states are expecting shortages by 2013. Water is intertwined with energy, too, since water supply and treatment plants consume about 56 billion kilowatt-hours per year--enough electricity to power more than 5 million homes for a year.

Lav faucets are undergoing a sea change as the EPA's new low-flow standards begin to take effect. Last fall its WaterSense program--the plumbing equivalent of Energy Star--began certifying bath faucets that achieve a maximum flow rate of 1.5 gpm, a 20 percent reduction from the old standard of 2.2 gpm.

To earn the WaterSense label, bath faucets must pass a third-party test proving that they not only use less water but also function as well as their less-efficient counterparts. To maintain a solid level of performance, WaterSense set a high and low spec ranging from 1.5 gpm at 60 psi to .8 gpm at 20 psi. (Psi varies based on a home's distance from the pumping station and the number of homes using it.)

"A faucet is a fairly simple device; there's only so much you can do with it," says Shawn Martin, technical director at the Chicago-based Plumbing Manufacturer's Institute. "The WaterSense studies showed that flows less than .8 at 20 psi didn't provide the level of performance the consumer expected. Their intent is on making sure the WaterSense logo comes to stand for water savings and decent performance."

In anticipation of the certification, plumbing manufacturers have been testing the appeal of low-flow fixtures for several years, and virtually every major group will convert their lav faucets to 1.5 gpm or less by the end of this year, without accompanying price increases.

Paul Patton, senior product manager at Delta Faucet, says his company's tests showed that consumers didn't notice the difference between standard and water-efficient bath faucets until the flow rate reached 1.0 gpm. "That doesn't mean we won't look at other technologies to see if we can deliver additional water conservation," he says.

To achieve a satisfying flow at 1.5 gpm or less, faucet aerators now typically include a pressure-compensating device. It delivers a heavier water force, allowing users to rinse the toothpaste out of their brush without running the water longer, which would counteract the savings. The technology also helps calibrate the flow to differing water pressure levels.

"A rubber O ring is squeezed into grooves in the flow plate, like a juicer with holes," explains Jerry Capasso, wholesale bath product manager for Moen. "It gives a very consistent flow rate over a wide range of pressures."

The jury is still out on the commercial success of WaterSense bath fixtures. But with the benefit of better technology and rigorous independent testing, the EPA expects the standards will quickly become the new "normal."

"The purpose of WaterSense is market transformation, like Energy Star," says Birute Vanatta, product manager at Eastern Research Group, the EPA's WaterSense contractor. "Once a product hits mainstream, we won't label it anymore." -- BUILDING PRODUCTS

Maura Dieringer contributed to this report.

American Standard. Asian-inspired Green Tea faucets project an elegant style while providing up to 32 percent water savings over standard models. All of the company's residential bathroom faucets are now WaterSense-listed at 1.5 gpm. Green Tea two-handle centerset and wide-spread lavatory faucets feature a pull-out spout that is virtually undetectable when not in use, the firm says. 800-442-1902. www.americanstandard-us.com.

Kohler. The Fairfax single-control faucet is WaterSense-certified with a 1.5-gpm flow rate. It features washerless ceramic-disc valves that exceed industry longevity standards by two times, the company says, and a high-temperature limit stop. Six finishes are available. 800-456-4537. www.kohler.com.

Hansgrohe. The contemporary-styled Talis S electronic faucet offers a 1.5-gpm flow rate for a 40 percent savings over conventional units. Infrared sensor technology starts and stops the water flow; models are offered with preset or adjustable temperature control. Battery or 110-volt operation is available. 800-334-0455. www.hansgrohe-usa.com.

Brizo. The RSVP bathroom faucet offers a sensual, Art Nouveau look designed to reflect a woman's curves, the company says, and the top of the lift rod can be specified with a metal, an angled blue glass, or a genuine Strass Swarovski round crystal finial. The WaterSense-labeled faucet uses 1.5 gpm. It is available in three finishes: polished chrome, brushed bronze, or brushed nickel. 877-345-2749. www.brizo.com.

Danze. The company has extended the Parma collection with three single-control Parma Trim Line variations--a vessel-filler model and two lav models. The units have a 1.5-gpm flow rate and are WaterSense-certified. They come in chrome or brushed nickel finishes. 877-530-3344. www.danze.com.

Delta. Lahara lav faucets are WaterSense-certified at 1.5 gpm. The products feature a high-arc spout and a design inspired by ocean waves. Models include a single lav with optional 4-inch center escutcheon, a two-handle 4-inch centerset, a 4-inch mini wide-spread, or 6- to 16-inch wide-spread deck mounts. Chrome, aged pewter, Venetian bronze, and Brilliance stainless finishes are available. 800-345-3358. www.deltafaucet.com.

Moen. The Lindley bathroom collection offers elaborate, traditional styling that will make a statement in today's baths. Lindley features single- and two-handle centerset faucets with both mid- and high-arc spouts. It is WaterSense-certified, using up to 32 percent less water without sacrificing performance, the maker says. 800-289-6636. www.moen.com.

Jaclo. The Roaring 20s faucet can be equipped with flow regulators for 1.5 gpm, the company says. The 7-inch swivel spout stops at 45 degrees to prevent spills on the counters. The unit features all-brass construction. It comes in oil-rubbed bronze with cross or lever handles. 800-852-3906. www.jaclo.com.

Barclay. The Alesia wide-spread faucet has a cone-shaped base, a delicately curved spout, and features either wing-like lever handles or trim cross handles. Upon request, an aerator can be inserted into the faucet for low-flow, 1.5-gpm operation, the company says. The faucet is solid brass and includes a ceramic-disc cartridge for drip-free operation. 847-244-1234. www.barclayproducts.com.

Price Pfister. The minimalist Kenzo faucet, available in chrome and satin nickel, is the industry's first wall-mount waterfall trough faucet, according to the company. With a water flow of 1.2 gpm, it is currently being tested for the WaterSense label. Mounting options include single-control centerset, single-control vessel, and 8-inch wide-spread. 800-732-8238. www.pricepfister.com.