A urinal is only used for collecting urine. Urinals are generally for men, although models for women have also been developed. Most urinals use water for flushing, but waterless urinals are becoming increasingly popular.
Urinals for women consist of raised foot-steps and a sloped channel or catchment area that conducts the urine to a collection technology. For men, urinals can be either vertical wall-mounted units, or squat slabs over which the user squats.
The urinal can be used with or without water and the plumbing can be developed accordingly. If water is used, it is mainly used for cleaning and limiting odours (with a water-seal).
For water-based urinals, the water use per flush ranges from less than 2 L in current designs to almost 20 L of flushwater in outdated models. Water-saving or waterless technologies should be favoured. To minimize odours and nitrogen loss in simple waterless urinal designs, the collection pipe should be submerged in the urine tank to provide a basic liquid seal.
Waterless urinals are available in a range of styles and complexities. Some urinals come equipped with an odour seal that may have a mechanical closure, a membrane, or a sealing liquid. Water-based Urinals use 8 to 12 litres of flushwater, whereas low-flush models use less than 4 litres of flushwater.
By putting a small target, or painted fly near the drain, the amount of spraying or splashing can be reduced; this type of user-guidance can help improve the cleanliness of the facility. Because the urinal is exclusively for urine it is important to also provide a toilet to be used for faeces.
Urinals can be used in homes as well as within public facilities. In some cases, the provision of a urinal is useful to prevent the misuse of dry systems (e.g., UDDT, U.2). Portable waterless urinals have been developed for use at large gatherings, to improve the sanitation facilities and reduce the point load of wastewater discharged at the site. In this way, a large volume of urine can be collected (and either used or discharged at a more appropriate location or time) and the remaining toilets can be reduced in number or used more efficiently. Urinals are appropriate for every climate.
The Urinal is a comfortable and easily accepted User Interface. In some cases, the provision of a urinal is useful to prevent the misuse of dry systems (e.g. UDDT). Although simple in construction and design, urinals can have a large impact on the well-being of a community. When men have access to a urinal, they may urinate less often in public, which reduces unwanted odours and makes women feel more comfortable. Men have generally accepted waterless urinals, as they do not call for any change of behaviour.
Operation & Maintenance
Maintenance is simple, but should be done frequently, especially for waterless urinals. All of the surfaces should be cleaned regularly (bowl, slab and wall) to prevent odours and to minimize the formation of stains.
Particularly, in waterless urinals, calcium- and magnesium-based minerals and salts can precipitate and build up in pipes and on surfaces where urine is constantly present. Washing the bowl with a mild acid (e.g., vinegar) and/or hot water can prevent the build-up of mineral deposits and scaling. Stronger (> 24% acetic) acid or a caustic soda solution (2 parts water to 1 part soda) can be used for removing blockages. However, in some cases manual removal may be required.
For waterless urinals, it is critical to regularly check the functioning of the odour seal.
The `Eco-Lily' from Ethiopia is made out of a common liquid container with a used light bulb acting as a floating `odour-lock' to reduce smells. The `Eco-Lily' is a device to be used as urinal both by men and women. SUDEA's experiences have showed that men can use it without any explanation while women often need some information on how to use it because of their biological difference.
This Factsheet gives useful information about the installation of as Waterless Urinal.
Helpful handwashing toolkit: Handwashing with Soap Toolkit
The material on this page was adapted from:
Elizabeth Tilley, Lukas Ulrich, Christoph Lüthi, Philippe Reymond and Christian Zurbrügg (2014). Compendium of Sanitation Systems and Technologies, published by Sandec, the Department of Water and Sanitation in Developing Countries of Eawag, the Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland.
The 2nd edition publication is available in English. French and Spanish are yet to come.