Best Management Practice: Toilets and Urinals
Toilets and urinals can account for nearly one-third of building water consumption. Old and inefficient toilet and urinal fixtures can be a major source of water waste in most commercial, residential, and institutional buildings, making the savings potential in this area significant.
This page outlines toilet and urinal best management practices across:
Current Federal law requires residential toilets (flush tank type) manufactured and sold in the U.S. after January 1, 1994, to use no more than 1.6 gallons per flush (gpf). Similarly, commercial toilets (flushometer valve type) manufactured and sold after January 1, 1997, must use no more than 1.6 gpf. Urinals must use no more than 1.0 gpf.
There are also toilets and urinals available on the market that exceed Federal standards called high-efficiency toilets (HETs) and high-efficiency urinals (HEUs). HETs consume no more than 1.28 gpf while HEUs consume no more than 0.5 gpf. The U.S. Environmental Protection Agency (EPA) WaterSense Program released specifications for high-efficiency tank-type toilets and high-efficiency flushing urinals. Federal sites are required to purchase WaterSense labeled or equivalent toilets and urinals per the Instructions for Implementing Executive Order (E.O.) 13423. Equivalent refers to toilets and urinals that have flush rates equal to or less than WaterSense specifications - 1.28 gpf for toilets and 0.5 gpf for urinals.
Operation and Maintenance
To maintain water efficiency in operations and maintenance, Federal agencies should:
Check for leaks every six months.
Establish a user-friendly method to report leaks and fix them immediately.
Encourage cleaning or custodial crews to report problems.
Periodically replace flush valves and fill valves in tank-type toilets.
When performing maintenance, replace worn parts and adjust mechanisms to ensure that the water consumed per flush meets manufacturer equipment specifications.
If non-water urinals are used, clean and replace the sealant, cartridges or material in accordance with manufacturer recommendations.
Regularly adjust and maintain automatic sensors to ensure proper operation.
The following retrofit options help Federal agencies maintain water efficiency across facilities:
Retrofits for tank-type toilets, such as displacement dams or bags, may hamper overall operation of the toilet and increase maintenance costs as they often have a short life span and require frequent replacement or adjustment. Therefore, they are not appropriate for Federal facilities.
Infrared or ultrasonic sensors for automatically flushing, flushometer valve-type toilets and urinals should not be considered a water-saving device. Rather, these devices make toilet and urinal operation fully "hands free" and sanitary. These devices need to be set properly and regularly maintained to avoid multiple flushing while providing sanitary advantages.
Early closure or valve insert or replacement devices can reduce flush volumes by 0.6 to 2 gpf. However, they often require frequent replacement or adjustment, may lead to clogging and other flush performance problems, and may void warranties on the fixture itself. Therefore, they are not appropriate for Federal facilities.
Consider using alternate sources of non-potable water for toilet and urinal flushing (see BMP #14). Package gray water treatment systems are now available that provide water filtered and treated sufficiently for these uses. If using alternate non-potable water for toilet and urinal flushing, monitor flapper valves and seals to determine if there is an impact on their useful life.
The following replacement options help Federal agencies maintain water efficiency across facilities:
Replace residential tank-type toilets with the WaterSense labeled products that have an effective flush volume of 1.28 gallons or less.
Consider replacing flushometer-type toilets in a commercial setting with high-efficiency toilets that use no more than 1.28 gpf.
For toilet retrofits, research and assess site-specific evaluation of existing waste lines, water pressure, distance, usage, settling, and types of users (employees, residents, occasional members of the public, high visitor populations, etc.), which is necessary to determine the appropriate models for a specific site.
Replace urinals with WaterSense labeled products or equivalent models designed to use 0.5 gpf or less. Note there are high-efficiency flushing urinals on the market that use as little as one pint per flush.
For maximum water savings and performance, purchase toilet valve and bowl in hydraulically matched combinations that are compatible in terms of their designed flushing capacity.
Avoid replacing existing urinal valves with high-efficiency valves if the bowl is designed to handle more than 1.0 gpf unless hydraulically matched bowls are also replaced.
Check the performance of toilet models through the Maximum Performance (MaP) Testing. MaP Testing provides results on the performance of numerous toilet models for both tank and flushometer toilets.
Consider installing piston valves for flushometer-type toilets and urinals. A key benefit of piston valves is that the valve fails closed rather than open. Valves that fail open continuously leak water until the valve is repaired or replaced.
Recycle used parts such as tank trim and metal flush valves (only the interior mechanism needs to be replaced) to minimize landfill impacts where appropriate.
Toilets and Urinals Resources
The following resources provide guidance on water best management practices.
EPA, WaterSense Program: Partnership program making it easy for Americans to save water and protect the environment through consistent measurement and labeling standards.
Alliance for Water Efficiency Toilet Fixture Introduction: Overview on high-efficiency toilets. The Alliance for Water Efficiency is a stakeholder based nonprofit organization that provides technical assistance and advocacy related to water efficiency and conservation efforts.
Alliance for Water Efficiency Urinal Fixture Introduction: Overview on high efficiency urinals. The Alliance for Water Efficiency is a stakeholder based nonprofit organization that provides technical assistance and advocacy related to water efficiency and conservation efforts.
Marshall Space Flight Center developed an innovative replacement program for toilets and urinals by researching appropriate fixtures, demonstrating technologies, and creating specifications for high-efficiency fixtures.