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Waterless Urinals Benefits and Pitfalls

Waterless urinals are a good and cost effective solution for most, but not all, sites. The choice of waterless urinal is key because whilst all types of waterless urinals will obviously save the same amount of water, they have different implementation and running costs.

The 3 main reasons why Gentworks clients choose to use waterless urinals are:

  1. to reduce overall expenditure, spending less than if flushed urinals were maintained or fitted
  2. to help meet environmental goals by reducing water usage and, by implication, the site's carbon footprint
  3. to improve reliability and/or resilience 

Waterless urinals can indeed provide these benefits, and do so for most sites where they are deployed. 

Understanding the Negative Implications of Using Water Containing Limescale to Flush Urinals
Most parts of the UK are supplied with 'hard' water that contains enough limescale to cause problems in urinals.

  • the supply pipes and cisterns become 'furred up' over time and require descaling to ensure a sufficient flush reaches each urinal
  • limescale combines with the uric acid salts in urine to form a hard scale, gradually blocking the waste pipes
  • bacteria can adhere to, and multiply in, the limescale film deposited on the surface of urinal bowls

The Benefits of Not Using Water to Flush Urinals
Note that where a site has urinals, they are typically responsible for between 15% and 35% of all the water used by the site!

  • save water, thus reducing energy and emissions 
  • reduce expenditure on water and related sewerage costs
  • improve hygiene, urinals easier to clean
  • no need to maintain flush control system, cistern or water supply pipes
  • no floods
  • reduce incidence of waste pipe blockage

Avoiding Potential Pitfalls of Waterless Urinals

The benefits from waterless urinals come from not having to use potable water that is costly to buy, requires CO2 emissions to produce, and deposits limescale in pipes. All waterless urinals will obviously save the same amount of water and give these benefits. However, there are potential pitfalls.

1. Will the Costs of Waterless Urinals Exceed the Savings?

The lower the cost of the waterless urinals, the more likely it is that savings will exceed those costs. It is important to assess the total cost of a waterless urinal solution over 1 to 3 years. Note that some suppliers may not be keen to reveal all the ongoing costs at time of sale. The total ongoing cost will include:

  • implementation of waterless urinal solution - parts and labour
  • consumables and frequency of replacement  
  • original supplier or 3rd party servicing charges, where applicable
  • changes to cleaning regime - labour and consumables

To project total savings, an assessment of current water use at the site is required, because....

  • Based on Gentworks survey data from hundreds of sites, the average annual water use per urinal is approximately 120 cubic metres (m3) per year. However, usage varies from around 29mto 235m3, depending on the level of flush control already implemented.
  • Urinals with properly calibrated flush controllers will typically be using less than 50m3 per year. However many are flushing much more than expected because the controllers are not correctly calibrated or have failed completely.

For most sites, the reduction in water use will account for more than 80% of the monetary savings from waterless urinals. Therefore making a reasonable assessment of these water savings will be the most important factor determining whether waterless urinals will actually save money for your site.  For guidance on assessing water savings, please click here.

Other savings, often very significant, will usually come from the reduced maintenance that most waterless urinal designs require compared with flushed urinals.. As a 'rule of thumb', if 85% of the annual costs of waterless urinals are offset by the reduction in the water bill, then the waterless urinals are highly likely to be saving at least as much as they cost.

2. Will Waterless Urinals Fail to Meet Expectations?

There are many people who hate the very idea of waterless urinals, and others who have had bad experiences of them. If you browse the web, you will doubtless find comments saying  that "they stink" and recommending "don't go waterless".  There are waterless urinals that smell, generally because they have not been properly installed or maintained. Of course, it is highly likely that you would have come across many flushed urinals that smell, for precisely the same reason. Whether waterless or flushed, some simple measures have to be taken to prevent odours. Most smell problems emanate from around the urinals due to poor cleaning and are completely unrelated to the type of urinal in use. As waterless urinals are still relatively new to most people, they tend to attract the blame for washroom odour problems, in most cases without any justification.
Why some people hate waterless urinals
  • Old systems were unreliable:  In the 1990s, there were some systems sold that were flawed in their approach and implementation. They tended to let odours from the urinal waste pipes vent into the washroom.
  • Capabilities oversold:  In a bid to generate sales in a difficult market, some potential users were told that all you had to do was put some device or chemical compound in the urinal bowl and turn the water off. This approach was never going to work for the user.
  • Zero Flushing Can Highlight Pipework Problems: Even in new buildings, the standard of pipework configuration can fall well below reasonable standards, and even water regulations. Gentworks engineers find that around 10% of washrooms need some remedial works prior to converting urinals to waterless use. Common problems include waste pipes that are running uphill, have multiple right-angled connections and inadequate rodding access so they have never been maintained properly. In addition, some vents and overflows are incorrectly connected into the urinal waste pipes and floor drains are inherently smelly. Whether or not urinals are to be converted to waterless, such issues should be resolved to avoid problems with blockages and odours. Converting to waterless can solve some such problems but exacerbate others.
  • Incorrect Maintenance: It is vital to follow the correct maintenance regime for the type of waterless urinal used. 
  • Incorrect Cleaning: This is the most common cause of failure for waterless urinals. Regular use of cleaning products containing strong acids, alkalis or bleach will destroy the 'good' bacteria  in microbiological systems and degrade the gel in barrier systems. Even valve systems can cease to operate correctly due to a strong cleaning chemical effecting the flexibility of the valve.