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How much water is used to flush a toilet?

Toilet water use can vary significantly. How much water does it take to flush a toilet? Older toilets can use 3.5 (13 litre) to 5 (19 litre) or even up to 7 gallons (26 litre) of water with one flush. Federal plumbing standards now specify that new toilets can only use up to 1.6 gallons (6 litre) per flush (GPF), and there are high efficiency toilets that use up to 1.28 GPF.
Replacing an older model toilet with a new high efficiency toilet (1.28 GPF) can greatly affect your household’s total water usage. HET’s (High Efficiency Toilets) are widely available at home improvement and plumbing stores, and typically cost about $100-400 plus any installation fees. The estimated payback time for a HET typically ranges from half a year to five years depending on the cost of your toilet and your household’s annual water and sewer costs. If purchasing and installing a new toilet is not possible, you may be able to retrofit your older toilet.

The national average for a gallon of water is 2/10ths of a cent per gallon. Many municipalities also charge sewer rates based on water usage, so to compensate for that, we’ll calculate it at a rate of 3/10ths of a cent per gallon.

The average amount of water used in a flush has varied over time. Toilets from the 1950s use as much as eight gallons per flush. Over time, the total amount per flush has gone down drastically. Currently, the average toilet manufactured today uses about 1.5 gallons per flush. Since many people aren’t necessarily using brand new toilets, the average usage is two gallons of water use per flush.

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So, how many times does a person flush per day? A recent AWWARF study indicates the average person flushes a toilet 5 times per day. And a survey that we saw recently indicates that the average person has 1.5 “brown” flushes per day.

Water is not used up when you flush a toilet. It is “Recycled” into the water cycle. When we flush a toilet it goes back into the ground. None of the water is consumed. It is just moved from the ground to the toilet and back to the ground.

In the larger world, most water resides in the oceans. It evaporates and becomes rain. The rain finds its way into rivers and wells where it is piped to toilets and other domestic fixtures. After domestic use it finds its way back into the oceans. Again, no water is used up. It is just recycled.

The problem with water usage is related to how much water is available in any particular area and how many people and other animals want to use it. In big cities there are more people than the water systems can support.

New, High Efficiency Toilets (HETs) use 1.3 gallons (5 liters) per flush (gpf). With an HET, a family of four will use approximately 9,000 gallons (34000 litre) per year in toilet water. Look for the toilet label to ensure your new toilet has maximum efficiency and high performance.

The Older Toilets made from the early 1980s to 1992 typically used 3.5 gallons per flush (13.2 liters) or more. Toilets made prior to 1980 typically used 5.0 to 7.0 or high gallons per flush (18.9 lpf to 26.5 lpf). The oldest toilets can use more than 8 gallons per flush (30 lpf).

How much water is used to flush a toilet in litres?

New toilets will using between 6 to 10 litres of water with each flush where high efficiency toilets can go below to even 5 litres of water. The older toilets if not altered can use between 13 litres to 19 litres of water each time.

What is High Efficiency Toilets (HET)?

An HET is a toilet that flushes at maximum of 1.3 gallons (5 liters) per flush. There are more than 1,100 models of HET toilet on the market today. New fixture models have been introduced and the performance of HETs has improved dramatically. Today, HETs outperform their ULFT (1.6 gpf/6 liters) predecessors as well as the 3.5 gpf (13.2 liters) toilets that were installed in the 1980s.

How to save water? Toilet Water Saving Tips

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Install a new high efficiency toilet (HET) model to save water.

Do not use the toilet as a trash can. Trash should be discarded in the garbage.

If you hear the water running in the toilet tank for an unusual length of time, a simple adjustment can return it to normal operation.

If your toilet has a water line indicator on the tank, make sure the water is at or below this line when the toilet refills.

If your home has a dual flush toilet try to use the low volume flush mode as much as possible. Experiment to see how much the low flush can handle.

Using Dual-Flush Toilets

Toilets consume an average of 20.1 gallons of water per person, per day in a home with no water-conserving fixtures, according to the American Waterworks Association. That’s nearly 30 percent of an average home’s daily per-person indoor water use. Upgrading from a 3.5 gpf (gallons per flush) toilet to a 1.6 gpf model will reduce one person’s annual water use from 27,300 gallons to 12, 500 gallons, according to the Federal Energy Management Program.

The dual flush technology was first developed in the 1980’s, the dual-flush toilet takes water-efficiency one step further: using 1.6 gallons for solid waste and only .8 gallons for liquid waste. You can find the best dual flush toilet HERE.

What kind of savings can  expect you with a dual-flush toilet?
Reduce water usage up to 30%. Total savings depend, of course, on frequency of use. You’ll also save on sewer costs, because they reduce the load on the waste system.

But our topic today, toilet flushing, requires between1.5 and five gallons per flush, depending on the age of toilet one uses. Combined, the typical American flushes away 24 gallons of water each day, nearly a quarter of our total water consumption.

We don’t naturally quantify all that flushing in dollars and cents, but like everything else in life, toilet water costs money. The OGWDW estimates that the average cost of water is $2 for 1,000 gallons, or, approximately 4.8 cents per person, per day, for 24 gallons of toilet water.

In total, the roughly 300 million Americans spend more than $5 billion dollars a year flushing their toilets.

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