How much water can be saved by using waterless urinals?

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Waterless urinals are becoming more popular as people look for ways to save money and be environmentally friendly. They work by letting urine flow down through small holes or a grating at the bottom of the bowl into a small reservoir called a trap. Inside this reservoir, the waste flows through a barrier of sealant, which traps odors and prevents the urine from being exposed to air. The urine then flows through a pipe and into the drainage line for the bathroom. Unlike traditional urinals, waterless urinals don’t need to be forced out. They were invented in the 1990s, but they have become more popular recently due to the push towards green construction.

H2O by the Numbers

Waterless urinals operate without water. The only water needed is a small amount used to flush the drain line every few months as part of regular maintenance. The amount of water saved by waterless urinals depends on a lot of variables, including the amount of water the old urinal used, the number of people who will use the new urinal and how often those people will use it.

Replacing a urinal can lead to water savings, but the amount saved depends on the type of urinal being replaced. Toilets can use anywhere from 1 to 3 gallons of water per flush, with newer models using less water than older ones. A single urinal can use between 20,000 to 45,000 gallons of water per year, and a larger building with three urinals and 120 male employees could save up to 237,000 gallons of water per year by switching to waterless urinals. The cost of water can be expensive, and waterless urinals typically pay for themselves in water bill savings within the first one to three years. The cost of a waterless urinal can start between $250 and $500, and maintenance costs are low. While there are some upkeep costs, such as replenishing sealant and replacing cartridges, waterless urinals are less prone to malfunction. However, urinals have a limitation in that they can only be used by about 50% of the population.

Lots of Additional Information

Related Articles

  • Understanding Waterless Toilets
  • How Do Toilets Function?
  • Exploring Tankless Toilets
  • How Dual Flush Toilets Work
  • The Mechanics of Low-Flow Toilets
  • Examining the Environmental Impact of Self-Contained Composting Toilets

More Useful Links

  • Waterless Urinal “Cost Saving Analysis” Tool
  • Waterless Urinal Savings Chart
  • Waterless Urinal Rebates


  • Cutraro, Jenny. “No Flush: Let the Yellow Mellow.” Wired. March 3, 2006. (April 14, 2011)
  • Davis, Joshua. “Pissing Match: Is the World Ready for the Waterless Urinal?” Wired. June 22, 2010. (April 12, 2011)
  • Stumpf, Annette L. “Waterless Urinals A Technical Evaluation.” U.S. Army Corps of Engineers Engineer Research and Development Center. January 2007. (April 12, 2011)
  • Reichardt, Klaus. “Five Fast Facts about Waterless Urinals.” Buildings. Sept. 13, 2010. (April 14, 2010)
  • Reichardt, Klaus. “How to Clean and Maintain Waterless Urinals.” Buildings. June 28, 2006. (April 14, 2011)
  • Waterless Co. “Ecotrap.” (April 11, 2011)
  • Waterless Co. “Simplicity Works.” (April 11, 2011)
  • Waterless Co. “Water Conservation.” (April 11, 2011)
  • Wilson, Alex. “Is America Ready for a Home Urinal?” Green Building Aug. 24, 2010. (April 15, 2011)
  • Zero Flush. “Daily Cleaning.” (April 12, 2011)
  • Zero Flush. “ZeroFlush: A Simple 7 Step Process.” (April 12, 2011)


1. How do waterless urinals work?

Waterless urinals use a trap system that separates urine from the air, which prevents odors from escaping. The trap is filled with a liquid sealant, usually an oil-based substance, that allows urine to pass through while preventing air from escaping. The urine then flows into the drain, leaving the trap full of the sealant.

2. How much water is saved by using waterless urinals?

Waterless urinals save an average of 20,000 to 45,000 gallons of water per fixture each year, depending on usage. This is because traditional urinals use anywhere from one to three gallons of water per flush, while waterless urinals require no water at all.

3. Do waterless urinals require any maintenance?

Yes, waterless urinals do require some maintenance to ensure they function properly. The liquid sealant in the trap needs to be replaced periodically, typically every three to four months, depending on usage. The urinals also need to be cleaned regularly to prevent buildup and maintain hygiene.

4. Are waterless urinals more expensive than traditional urinals?

Yes, waterless urinals are generally more expensive than traditional urinals due to their specialized trap system and installation requirements. However, the cost savings from reduced water usage can offset the initial expense over time.

5. Can waterless urinals be retrofitted into existing plumbing systems?

Yes, waterless urinals can be retrofitted into existing plumbing systems with some modifications. However, it is important to consult with a plumbing professional to ensure proper installation and compatibility with the existing system.

6. Do waterless urinals have any environmental benefits?

Yes, waterless urinals have several environmental benefits in addition to water conservation. They reduce the amount of wastewater produced, which can reduce the strain on treatment facilities and prevent pollution. They also reduce the energy needed for water treatment and transportation.

7. Are waterless urinals suitable for all types of buildings?

Waterless urinals can be used in most types of buildings, including commercial, industrial, and residential. However, it is important to consider factors such as usage and maintenance requirements when determining if waterless urinals are appropriate for a specific building.

8. Are waterless urinals hygienic?

Yes, waterless urinals are hygienic when properly maintained and cleaned. The sealant in the trap prevents odors and bacteria from escaping, and regular cleaning and maintenance can prevent buildup and ensure proper functioning. Additionally, the lack of water can prevent the spread of waterborne diseases.

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