It's one of the most critical pieces of technology in your home. And though most consumers don't think of their humble toilet as a tech product, researchers and engineers at global companies like Caroma and Toto are racing to improve designs so toilets consume far less water.
Recent droughts, a growing global population and concerns about the impact of climate change on the world's water resources have led to a surge of interest in water conservation as well as efforts to "reinvent the toilet" to convert human waste into fertilizer and fuel.
Americans use vast quantities of water -- on average, 350 gallons a day. Toilets and bathrooms are the main source of water use in the home, with toilets accounting for
Many older toilets use from 3.5 gallons to as much as 7 gallons per flush, or gpf. With the average person flushing at least five times a day, that quickly adds up. A 1.6 gpf toilet, which became the industry standard in the 1990s, uses about 2,900 gallons a year. Switching to a 1.28 gpf "High Efficiency Toilet," or HET, cuts that to 2,300 gallons a year.
Santa Clara County residents can qualify to receive up to $125 per toilet for replacing high water-use toilets with a new HET.
"We found that 30 to 40 percent of the residential toilets in Santa Clara County are old, or pre-1992," said Karen Morvay Koppett, a senior water conservation specialist with the Santa Clara Valley Water
The basic parts of a toilet include the tank, the bowl and the "trapway," or snakelike tube on the side of the toilet that the water flushes through. Standard toilets use what's known as a "gravity" flush.
Some HETs use "pressure assist" technologies, where a pressurized air tank helps push water down the drain. But those systems suffered a setback late last month, when the Consumer Product Safety Commission announced a voluntary recall of the Flushmate III Pressure-Assisted flushing system after reports of tank lids shattering. The company, based in Michigan, received 304 reports of the units in toilets bursting, resulting in property damage and 14 impact or laceration injuries.
Toto, a Japanese company, holds the Guinness Book of World Records for creating the toilet with the most functions: a model with a heated seat that lifts automatically, an air freshening and deodorizing function and auto cleansing.
But Toto says its most significant advancement to date is a one-gallon-per-flush gravity toilet, an industry first. The toilet features Toto's Double Cyclone flushing system that the company claims "marries flawless performance and exceptional bowl cleansing action to ultra high-efficiency water-savings, creating a clean, green flushing system that saves money, water, and time." The model, which costs about $600, should hit the U.S. market this fall.
"The challenge is to master the physics of moving water and waste through the bowl," said David Krakoff, senior vice president of sales at Toto USA. "Our technologies have focused on different siphon designs, and the mastery of using different angles and water paths to create the flushing force in the bowl. The Double Cyclone has two "jets" that propel the water with a circular vortex action."
Caroma, based in Australia, invented what's known as "dual flush technology" 30 years ago. Those toilets come with two buttons -- one for bowel movements, one for urine. The "heavy flush" dispenses 1.28 gallons of water, while the low-flush option uses just 0.8 gallons, making it one of the most water-efficient flushes on the market. Though not as common in the United States, dual flush toilets have been mandated in Australia and New Zealand since 1992.
"Australia is the driest continent in the world, and water is a real scarcity there," said Doug Sproule of Caroma USA. "We first introduced dual flush in North America in the 1990s, and its becoming more popular in places that are looking to save water, from Los Angeles to Pasadena and Redwood City. We've also installed them in a lot of hotels in California."
The Bill & Melinda Gates Foundation, which largely focuses on global health issues, notes that worldwide, 2.6 billion people don't have a safe, affordable way to go to the bathroom, leading to widespread sanitation, hygiene and health issues. Last July, in Rwanda, the foundation called for a bold strategy to "reinvent the toilet" and announced $42 million in grants aimed to spur innovations in the capture and storage of human waste, including waterless toilet that don't rely on sewer connections and ways to turn waste into reusable energy and fertilizer.
Graywater -- a term for reused water -- is the next frontier. Some toilets on the market use graywater from the wash basin or sink to refill the toilet tank, but consumers first need to replumb their home for indoor graywater use.
Composting and dry toilets, which typically use no water at all, are also increasingly available. Home Depot sells a waterless composting toilet for $1,299. Loowatt is a UK-based startup that converts waste into natural gas and fertilizer. The company is currently setting up pilot systems in sub-Saharan Africa and the United Kingdom and hopes to be on the public market in 2013.
The East Bay Municipal Utility District, or EBMUD, serves 322,000 homes in a 331-square-mile area that stretches from Crockett to Berkeley, Oakland, and south through the San Ramon Valley. EBMUD currently offers consumers a $100 rebate for purchasing an HET, with a limit of 2 toilets per household, if the toilet they are replacing uses 3.5 gallons per flush or more. The rebate program, which was set to expire June 30, was renewed July 1 for another six months.
"It's always prudent to be water efficient in the Bay Area," said Abby Figueroa of EBMUD. "Even beyond the flushing, it's the leaks in the toilet that's often a bigger problem. A small leak can waste a lot of water."
Contact Dana Hull at 408-920-2706. Follow her at Twitter.com/danahull.