Washrooms experience high volume usage and obviously require robust fixtures and fittings so it makes sense to go for options that reduce long-term operational and maintenance costs. A number of tried and tested water-saving technologies are now available that are environmentally friendly and offer significantly reduced water bills and fewer maintenance call-outs.
WC’s can make a significant contribution to water consumption at transport hubs and account for up to 90 per cent of water use for public conveniences. As from January 2001, all new WC’s installed in the UK have to have a maximum flush of six litres.
A range of low-flush WC’s are now available, most with dual flush options. These are often dependent on valve flush mechanisms, rather than the traditional UK siphon flush. However, there is an ongoing debate about the relative water-saving advantages of valve and siphon flush systems due to valve systems’ potential for leakage.1
The siphon flush is, by the nature of its design, inherently leak free. Valve flush mechanisms can potentially leak down the back of the WC pan. Where this leakage is undetected for some time, long-term water usage can be increased. Valve mechanisms are also less robust than the traditional UK siphons, with which UK plumbers are more familiar, and dual flush users may also need to be educated to avoid double flushing.
Specialist supplier Green Building Store supplies a range of water-saving WC’s (both valve and siphon) but recommends the use of siphon flush WC’s, particularly in station facilities and other public buildings, where close monitoring and detection of leakage might be difficult.
Flush volumes and mechanisms are not the only factors that can affect the water efficiency of WC’s. Water can also be wasted while the cistern refills during the flush. It is now possible to get delayed-action inlet valves for siphon flush WC’s, which save water by preventing the cistern refilling until the flush is finished.
Concerns about maintenance and ‘drain carry’ of low flush WC’s have been dispelled thanks to a 2004 independent study (commissioned by the Environment Agency et al) of an installation of water-efficient WC’s at St Leonard’s School, Hastings. The report shows that maintenance problems declined dramatically following replacement of old nine litre WC’s with ultra efficient ES4 toilets. ‘The new toilets have not only reduced water consumption, but previous problems with poor flush and unpleasant smells have completely disappeared.’
The 1999 Water Regulations stipulate that there should be a maximum water usage of 7.5 litres per urinal bowl per hour, and that a device should be fitted to prevent the urinals flushing when the building is unoccupied.
However, in practice, flush rates are often adjusted in an attempt to reduce odour or blockage, and flushing can continue for 24-hours a day, seven days a week. For some offices and buildings, this could mean that up to 76 per cent of flushing could occur when the building is unoccupied.
Flush control technologies are now available for urinals including: timer controls, infra-red or ultrasound sensors. Some flushing systems respond to variations in water pressure or flow, for example when taps are used.
However, to maximise water-savings, specifiers often opt for waterless urinal systems. Waterless urinals also offer the advantages of being more vandal and frost-proof and less prone to blockage. However, instead of using water, many use disposable cartridges or oils, which themselves can involve significant environmental and maintenance costs. With such products, according to the Water Regulations Advisory Scheme, ‘It is necessary to evaluate the cost of cleaning chemicals and manpower against the savings from fewer water fittings and the use of water.’ A recent development has been the Airflush urinal system which uses neither water nor consumables. Instead, the system combines the use of a low energy electric fan which removes odour by maintaining a flow of air down hygienically designed urinal bowls.
Taps can be fitted with spray inserts and aerators, which help reduce water use while providing sufficient flow for hand washing – a 1.7 litre spray is ideal for washrooms. To save water without having to replace taps, in-line flow regulators limit flow instead in the supply pipe and can limit the maximum flow to four litres per minute.
Electronic sensor taps and timed turn-off push taps can also prevent wastage and flooding from taps being left running.
Bath Spa station
Oxford Architects completed a refurbishment of Bath Spa in 2012 for Network Rail, which encompassed refurbishment of waiting rooms, front canopy and stonework, stairwells and lighting. In addition, it undertook a refurbishment of washrooms (including male/ female and disabled facilities) on platforms 1 and 2 for First Great Western. This involved replacement of all sanitaryware, as well as refurbishment of wall/ floor tiles and cubicles.
Green Building Store supplied ES4 WC’s a siphon flush system with a low flush of 4 litres per flush, and with public ‘palm push’ button, and the Airflush urinal system for the project.
Alistair Jackson at Oxford Architects said: ‘We chose the ES4 WC and Airflush system because of their robustness and ability to work well in high usage situations. Our clients First Great Western were very keen on reducing water consumption and both products offered significant water savings. Feedback on the products has been positive and we are planning to use the ES4 WC’s at a forthcoming refurbishment of Bristol Temple Meads station.’
The Grade II listed Ormskirk was neglected and under-utilised, with inadequate toilet facilities, comprising just one shared male/female toilet in poor condition. SBS Architects undertook a complete refurbishment and internal remodelling of the station building on behalf of MerseyRail and Lancashire County Council, completed in summer 2009. The refurbishment won a National Railway Heritage Award in 2011 and a Station Development Award in 2010.
The station’s new toilet facilities comprise five toilets, including disabled facilities. SBS Architects specified water-efficient ES4 WC’s from Green Building Store for use in the washrooms. Lancashire County Council and MerseyRail were very supportive of the eco features at Ormskirk and endorsed all measures that would help reduce long-term operational and maintenance costs.
For further information contact Nell Griffiths, water efficiency manager, Green Building Store. Tel: 01484 461705