Toilets- Low Flush vs. Dual Flush
The federal government decided that after 1994 toilets shouldn’t use any more than 1.6 gallons of water per flush. Manufacturers had to comply.
For a time, toilets were called necessaries, one in a long line of euphemisms used to describe the business end of handling a simple biological process. Originally, our “toilets” were called “outhouses and were located outside the home. With the advent of indoor plumbing, toilets were move inside our houses, but in the American culture, the elimination of bodily waste remained a delicate topic. Cultural bias has been one reason why we have been slow to make changes to the toilets Americans use.
Prior to 1994, most toilets on the market used at least 3.5 gallons, or about 20 gallons of water per person per day — the most water used by any household appliance. Twenty-one years ago, the Federal Government began enforcing new legislation which mandated that the maximum toilets could use per flush was 1.6 gallons.
That was a decade and a half ago. Manufacturers now offer a wide variety of low-flow models that followed work as well than toilets that used to use many more gallons per flush. By choosing a low-flow toilet that works well, not only will you save money on your water bills, but you will get a reliable toilet that helps conserve water.
Today’s consumers have a wide variety of high-efficiency toilets to choose from (including some that use as little as 1.28 gallons!). Another option that is relatively new to the US, are dual-flush toilets. These types of toilets (which have long been available in Europe), feature have separate flush modes for solid and liquid waste, increasing the opportunity to save on water consumption.
Toilets are by far the main source of water use in the home, accounting for nearly 30 percent of residential indoor water consumption. Toilets also happen to be a major source of wasted water due to leaks and/or inefficiency
In the next section, we’ll see why interest in low flow and dual flush toilets is on the rise in the United States, initially due to government regulation and education, and more recently by growing concerns about the cost and availability of (arguably) our most precious resource: water.
Low Flush Toilets
Recent advancements have allowed toilets to use 1.28 gallons per flush or less while still providing equal or superior performance. This is 20 percent less water than the current federal standard of 1.6 gallons per flush.
A large number of companies are offering high-efficiency toilets (HETs). This includes at least twenty-two manufacturers who provide toilets that use 1.28 gallons per flush (gpf) or less. The Federal Government provides information on how consumers can easily find low-flow toilets. WaterSense, a program sponsored by the Environmental Protection Agency, offers certification for a range of water-efficient products and appliances. Toilets must be able to dispose of 350 grams of solid waste in a single flush. Only water–saving toilets that complete the certification process can earn the WaterSense label.
Dual Flush Toilets
Interest in low flow and dual flush toilets is on the rise in the United States, due in part to increased government regulation and the rising cost of water, and there are incentives for making changes in the way we use the toilet.
Dual flush toilets handle solid and liquid waste differently from standard toilets, by giving the user a choice of flushes. It’s a design that helps conserve water that has caught more readily in countries where water is in short supply, like Australia, and also in areas where water treatment facilities are older or overtaxed. In a 2013 report, The Environmental Protection Agency (EPA) estimated that 36 states would begin to experience water shortages as a result of increased water usage and inefficient water management from aging regional infrastructures. Using less water to flush liquid waste makes sense, but in the United States there remain cultural biases that make accepting this on approach to personal waste harder to accept.
How the Dual Flush Toilet Handles Waste
The way water is used to remove waste from the bowl has a lot to do with how much water is needed to get the job done. Standard toilets use siphoning action, to evacuate waste. A high volume of water entering the toilet bowl when the toilet’s flushed fills the siphon tube, pulling the waste and water down the drain. When air enters the tube, the siphoning action stops. Dual flush toilets employ a larger trapway (the hole at the bottom of the bowl) and a wash-down flushing design that pushes waste down the drain. Because there’s no siphoning action involved, the system needs less water per flush, and the larger diameter trapway makes it easy for waste to exit the bowl. Combined with the savings from using only half-flushes for liquid waste, the dual flush toilet design can save up to 68 percent more water than a conventional low flow toilet.
Using a larger diameter trapway, dual flush toilet do not clog as often, need less water to flush efficiently, resulting in a reduction in water necessary for flushing liquid waste. The tradeoff to consider, as well is that dual flush units are a little more expensive than other low flow toilet designs.
|According to the EPA’s WaterSense program, if all the old, inefficient toilets in the United States were replaced with WaterSense labeled models, we could save 520 billion gallons of water per year, equivalent to the amount of water that flows over Niagara Falls in about 12 days|
Related Topic: – Why Should You Care About Water Efficiency?