WaterSense at Work: Best Management Practices for Commercial and Institutional Facilities
A urinal is defined in the applicable national standard for urinals as “a plumbing fix-
ture that receives only liquid waste and conveys the waste through a trap seal into a
gravity drainage system.”
Flushing urinals use water to remove (i.e., flush) the liquid
waste from the fixture. Flushing urinals use a variety of different technologies. Wash-
down or washout urinals require the activation of a flushometer valve. Gravity tank-
type urinals, which are less common, rely on the release of water stored in an in-wall
cistern to provide the necessary water pressure and flow to remove waste from the
urinal, similar to the operation of a gravity tank-type toilet. Siphonic jet urinals have
an elevated flush tank and operate by using a siphon device to automatically dis-
charge the tank’s contents when the water level in the tank reaches a certain height.
This type of urinal requires no user activation.
Flushing urinals can be equipped with
electronic sensors that activate the flushing
mechanism when a user has finished using
the fixture. Automatic flush sensors provide
no additional water-efficiency benefits.
They do, however, provide health and
sanitation benefits in public-use facilities
because they offer a hands-free option. Al-
though, if not properly operated, automatic
flush sensors can cause double or phantom
flushing, actually increasing the water used
at a facility.
Flushing urinals come in two basic
types—standard, single-user fixtures and
trough-type, multi-user fixtures. Trough-
type urinals are large fixtures designed for multiple users in high-traffic places, such
as stadiums and sports arenas. Trough urinals are sold in 36-, 48-, 60-, and 72-inch
lengths. Some older models were designed to run continuously and, consequently,
consumed large amounts of water. New trough urinals either use flushometer valves
on preset timers or are equipped with electronic sensors.
Some urinals do not use water to flush the liquid waste from the fixture. A non-water
urinal is “a plumbing fixture that is designed to receive and convey only liquid waste
through a trap seal into the gravity drainage system without the use of water for
Non-water urinals use a specially designed trap that allows liquid waste to drain out
of the fixture, through a trap seal, and into the drainage system. Many non-water
American Society of Mechanical Engineers (ASME), Canadian Standards Association (CSA). August 2008. ASME A112.19.2-2008/CSA B45.1-08,
International Association of Plumbing and Mechanical Officials (IAPMO). February 19, 2004. IAPMO Z124.9-2004,
American National Standard for Plastic