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Best Management Practice: Toilets and Urinals

The U.S. uses 4.8 billion gallons of water every day to flush waste. Toilets and urinals account for nearly one-third of building water consumption, making the savings potential in this area significant.

This page outlines toilet and urinal best management practices across:

Overview

Unless your facility is relatively new or recently refurbished, chances are that your toilets and urinals are consuming too much water. 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.

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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 seal cartridges or material in accordance with manufacturer recommendations.

  • Correctly adjust and maintain automatic sensors to ensure proper operation.

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Retrofit Options

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.

  • 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., liquid waste 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 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 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 non-potable water for toilet and urinal flushing, monitor flapper valves and seals to determine if there is an impact on their useful life.

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Replacement Options

The following replacement options help Federal agencies maintain water efficiency across facilities:

  • 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% 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 WaterSense Web site.

  • Replace urinals with high-efficiency models designed to use 0.5 gpf or less. Also note that flushing urinals have a distinct advantage over non-water urinals in that the costs of replacement components and fluids are largely avoided. Also, the flushing action can remove concerns over odors, and facility maintenance and custodial tasks are routine.

  • 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 headquarters engineers, but do not overlook water utilities, contractors, or other Governmental agencies.

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Toilets and Urinals Resources

The following resources provide guidance on water best management practices.

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