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BMP #6 - Toilets and Urinals

Background

The United States uses about 4.8 billion gallons of water every day to flush waste. Since toilets and urinals account for nearly one-third of building water consumption, the potential for savings in this area is significant. Unless your facility is relatively new or has been refurbished recently, chances are that your toilets and urinals are consuming too much water. Current Federal law requires that residential toilets (flush tank type) manufactured and sold in the U.S. after January 1, 1994 must 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 and urinals must use no more than 1.0 gpf. Toilets rated at 1.6 gpf are termed Ultra-Low-Flush (ULF) toilets.

ULF toilet fixtures, those that meet or exceed Federal requirements, continue to be the topic of a great deal of discussion. When first introduced, these fixtures were often judged to be inadequate in terms of water savings and performance due to reports of clogging and double flushing. Problems arose with these early toilet models when tanks were modified with "early closing flappers" and other devices to reduce the volume of water per flush, without changing the bowls. The poor performance of these early models (from about 1992 to 1998) continues to cast a cloud of doubt over the ULF technology.

To address poor performance issues, manufacturers began serious re-engineering of 1.6 gpf models, addressing tank and bowl hydraulics, improving durability of tank components, and designing to more rigorous flush performance requirements. Overall, the improved design and technologies with these second generation models yielded more water savings and superior flushing capabilities, even when compared with older inefficient (3.5 gpf) toilet models. In fact, most surveys conducted to measure consumer satisfaction with the second generation models have shown an acceptance or satisfaction rate of more than 80 percent.

The third generation of toilet models resulted directly from the product development leading to the very successful 1.6 gpf toilet fixture. In 1999, the first High-Efficiency Toilet (HET) fixture was introduced into the North American marketplace. With superior hydraulic design, HETs flush at an effective flush volume of 1.28 gpf or less, or 20 percent below that required by the current national standard. Because of this design and other innovative features, HETs are now able to actually exceed the waste removal performance of the 1.6 gpf fixture.

In recognition of the advancements made in toilet performance and customer acceptance, EPA's WaterSense program developed a performance specification to recognize and label tank-type HETs. WaterSense labeled toilets are not only 20 percent more efficient, but must also pass a rigorous waste removal performance test, something that other toilet fixtures are not required to do.

Urinal technology has also improved significantly since the implementation of the Federal law in the early 1990's. Again, with the redesign based on the improved hydraulics of the fixture, the amount of water needed to effectively remove waste has been significantly reduced. Today, High-Efficiency Urinals (HEUs), which function at 0.5 gpf and less, are available from a range of manufacturers. Not all models from these manufacturers, however, employ the same technology, nor do they all require the same amount or frequency of maintenance. As such, it is critical that the building designer, specifier, and/or facility manager carefully weigh all of the attributes and shortcomings of the various technologies available today in the marketplace. This includes a thorough assessment of life cycle costs, with special consideration given to the maintenance and/or replacement parts needed over the product lifetime of certain technologies.

Today, HEUs come in a wide array of water use profiles, e.g., 0.5 gpf, 0.25 gpf, 0.125 gpf, and non-water fixtures. The most recent technology introduced in North America is the 0.125 gpf (1 pint per flush); the response from facilities managers who have installed these urinals is excellent. Flushing urinals have a distinct advantage over non-water urinals in that the costs of replacement components and fluids is largely avoided, the flushing action can remove concerns over odors, and facility maintenance and custodial tasks are routine.

For more information on this and other FEMP Water Efficiency Best Management Practices (BMPs), please see the resources section.

Operation and Maintenance Options

  • Check for leaks every six months.
  • Establish a user-friendly method to report leaks and fix them immediately.
  • 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 manufacturers' original equipment specifications.
  • If non-water urinals are used, clean and replace the seal cartridges or material in accordance with manufacturer recommendations.
  • Encourage cleaning or custodial crews to report problems.
  • Correctly adjust and maintain automatic sensors to ensure proper operation.

Retrofit Options

  • 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.
  • For flushometer valve type toilets, infrared or ultrasonic sensors can be retrofit to automatically activate flushing, making their operation fully "hands free" and sanitary. However, these devices need to be set properly and regularly maintained to avoid multiple flushing and, while providing sanitary advantages, should not be considered as a water-saving device.
  • For some commercial flushometer valve type toilets (diaphragm type only), the existing flush valve can be retrofit with a dual-flush valve capable of delivering a reduced flush or a full flush depending upon the demand (i.e., liquids only or solid and liquid waste). Note that this type of retrofit may require significant user education to be fully successful. In addition, the existing bowl must be compatible with the reduced flush volume.
  • Early closure or valve insert or replacement devices can reduce flush volumes by 0.6-2 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 non-potable water for toilet and urinal flushing (see BMP #14). Package graywater treatment systems are now available that provide water filtered and treated sufficiently for these uses. If using non-potable water for toilet and urinal flushing, monitor flapper valves and seals to determine if there is an impact on their useful life.

Replacement Options

  • Replace 3.5 to 5 gpf toilets with flushometer valves and bowls specifically designed to use 1.6 gpf or less. For maximum water savings and performance, purchase the valve and bowl in hydraulically matched combinations that are compatible in terms of their designed flushing capacity. Avoid replacing only the existing flushometer valve or tank with a more efficient 1.6 gpf or less model if the bowl is designed to handle 3.5 gpf or more. 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.) is necessary to determine the appropriate models for a specific site. Where appropriate, recycle used parts such as tank trim and metal flush valves (only the interior mechanism needs to be replaced), to minimize landfill impacts.
  • If replacing tank-type toilets (gravity or pressure assist), select toilets with the WaterSense label. These have an effective flush volume of 1.28 gallons or less (20 percent savings per flush over traditional 1.6 gpf toilets) and have been independently tested and certified for performance. For a list of WaterSense labeled high-efficiency tank-type toilet models, please visit the EPA web site.
  • Replace urinals with HEU models designed to use 0.5 gpf or less.
  • In remote areas, consider replacing water-using toilets with alternative technologies such as composting or incinerator toilets.
  • For specifics on this technology, consult with experts in the field. Your first resource should be your local or higher headquarters engineers, but do not overlook or rule out the benefits of input from water utilities, experienced contractors or other Governmental agencies (FEMP, EPA's WaterSense Program, etc.)

Toilets and Urinals Resources

EPA's WaterSense Program.

U.S. Department of Energy. FEMP Purchasing Specification for Urinals.

U.S. Department of Energy, FEMP Focus: GSA's Richard Russell Federal Building Initiates Water Conservation Measures, November 2002 (PDF 5.5 MB). Download Adobe Reader.

Vickers, Amy. Handbook of Water Use and Conservation. WaterPlow Press. Amherst. 2001.