Toilets are an essential technology that we use each day. Yet for something that we use 5 times per day, most people don’t give toilets much thought (unless there’s a problem).
For decades, toilets used a lot of water each time they were flushed. Populations were lower in those days and people we more spread out. We weren’t too worried about groundwater and the level of our lakes and reservoirs.
In recent decades, with water shortages and drought becoming more obvious, society has searched for ways to reduce water consumption. Municipalities have invested in water treatment facilities, agriculturalists have begun using drip irrigation systems, and homeowners have turned to xeric landscaping and water-saving toilets.
In this article we’ll look at the evolution of toilets and how much water they use. We’ve come a long way in a short amount of time and our toilets, although they look the same, have improved their efficiency.
How Much Water Do Old Toilets Use
If you live in an older, pre-1990’s American home there’s a good chance you have an inefficient toilet. Prior to 1992, toilets used 3.5 and 5 gallons per flush, however, even older toilets might use up to 7 gallons per flush.
These toilets flushed well, but they utilized much more water compared to the toilets we use today.
You might be surprised to learn that many older homes still use the older toilets – existing toilets were not part of regulation so homes that have them can keep them until it’s worn out (toilets can last decades!).
Why Have Toilets Improved Their Water Use Efficiency (Federal Regulations)
In 1992, under the administration of President George Bush, the Environmental Protection Agency helped pass a law that new toilets could only use 1.6 gallons per flush or less.
Toilet companies were given a “heads-up” about the law and their engineers worked to develop new ways to improve water efficiency. A few of the changes the toilet companies made were:
1) increasing the flush valve from 2 to 3 inches which allowed more water to enter the bowl at a time
2) increasing the size of the toilet drain to reduce the chance of clogs
3) improving how water enters the toilet bowl
Years later, in 2006, the Environmental Protection Agency created the WaterSense Certification to highlight toilet models that used less than 1.6 gallons per flush.
Since this time, dual flush toilets have further reduced the amount of water that is used. Dual flush systems use less water for liquid waste and more water for solid waste. This allows most dual flush toilets to use an average of 1.28 gallons per flush.
In some States, homeowners can receive a rebate if they install a WaterSense or dual flush toilet.
Note: In California, Colorado, Texas, and Georgia, new toilet installations must meet the criteria of using 1.28 gallons per flush or less. These states have water regulations that are actually more stringent than WaterSense Certification Standards.
How Much Water Do New Toilets Use
You can be assured that new toilets use less than 1.6 gallons per flush, however, the exact amount of water use depends on the model of toilet.
Dual flush toilets will use various amounts of water for liquid and solid waste. Examples are:
- Toto Dual Flush – .9/1.6 gallons per flush
- American Standard Dual – .92/1.28 gallons per flush
- Woodbridge Dual Flush – 1/1.6 gallons per flush
- Kohler Dual Flush – 1.1/1.6 gallons per flush
>> read my article on the best dual flush toilets
Most new single flush toilets have reduced their water consumption to 1.28 gallons per flush. Just look for the WaterSense Certification to make sure.
Many tanks have the amount printed on the inside of the tank but it should also be highlighted on the box and description.
Facts About Household Water Use And The Impact Of WaterSense
Flushing a toilet may seem like an inconsequential amount of water, however, each flush adds up.
According to this water study in Seattle, the average person flushes a toilet 5 times a day. Over the course of a month, it equates to 150 flushes and over the course of a year it equates to 1,825 flushes.
Using this data, we should expect to use the following amount of water each year per person:
- 9,125 gallons (5 GPF)
- 6,388 gallons (3.5 GPF)
- 2,920 gallons (1.6 GPF)
- 2,336 gallons (1.28 GPF)
The difference in water consumption is huge!
- Since 2006 WaterSense Certification has helped save 2.7 trillion gallons of water https://www.epa.gov/watersense/accomplishments-and-history
- In 2017 WaterSense helped save 631 billion gallons of water
- WaterSense is also applicable for faucets and showerheads.
Conclusion
Knowing how much water toilets use depends on whether it’s a new toilet or an old toilet.
Old toilets, that were made prior to 1992, most often use 3.5 or 5-gallon tanks. Each flush would release 3.5-5 gallons into the bowl and it would do a great job of flushing the waste. But with fresh water consumption so high, and problems like drought occurring more frequently, regulation had to help toilet companies to improve their engineering.
New toilets use far less water per flush. Regulations required that post-1992 toilets needed to use 1.6 gallons per flush or less, however, many brands went above and beyond the regulation and use 1.28 GPF.
The WaterSense certification is a good way to know if a toilet exceeds the federal requirements but don’t rely solely on WaterSense as some states like California, Texas, Colorado, and Georgia have more stringent regulations.
Our bathrooms are the biggest user of water in our home and a simple flush of the toilet may seem like a small contributor to water use. Over time the flushes add up and upgrading to a new toilet can save a significant amount of water, while saving you money at the same time.
Thanks for reading another Toilet Travels article. Search our website to find answers to all toilet-related questions.