The toilets <and urinals> are mostly all original, and consist of tank urinals <flush urinals>, tank toilets, flush valve toilets. These fixtures are old and consume excessive amounts of water.
Modern low-consumption fixtures are designed as direct replacements for older fixtures. They use significantly less water without compromising performance. When they first came onto the market, low volume toilets developed a reputation for poor flush performance. In response, the industry has developed a rating process and the problems have been overcome.
• Replacing all existing toilets with new low volume (6 litres/flush) or dual-flush toilets. <Savings and cost estimates in this analysis are based on low volume toilets.>
• Replacing all existing flush valve urinals with low volume or waterless urinals. <Savings and cost estimates in this analysis are based on low flow urinals.>
Waterless urinals, which require no potable water at all, should be considered in non-residential applications. They are designed to operate with no water, minimizing maintenance and eliminating the need for water service. Waterless urinals take some getting used to, for occupants and cleaners, so affected parties should be consulted before proceeding.
Low-flow toilets are not created equal. Expect to pay more for a good one that will reliably remove solids in a single flush, will not clog frequently, and will sustain water savings over its useful life. Refer to the most recent MaP report from Veritec Consulting, which reports testing results of toilet performance. When referencing the tables, look for a minimum of 350g solid waste removal in a single flush. As little as 250g capability is considered passable, but there is no reason to accept less than 350g performance since there are many capable models available from a wide range of manufacturers.
Aside from initial performance, it is wise to choose toilets known to sustain water savings for the long term (i.e. not to leak or use more water as they age). The California Urban Water Conservation Council has issued a report on High Efficiency Toilets (HETs), identifying the best toilets in this regard. Those toilets are identified in the MaP report as "SPS-qualified". SPS-qualified, gravity-fed (rather than pressure-assisted) toilets are more likely to sustain water savings over their physical lifetime.
If you are using adjustable HETs, they must be adjusted after installation to their rated flush volume.
A good way to detect leaking fixtures is to monitor your water meter during times when you would expect no water use (1:00 a.m. - 5:00 a.m. in family & seniors buildings). Substantial overnight water consumption may indicate that toilets, taps or bath/shower fixtures are leaking.
Include twice yearly inspection and replacement of all tap washers in the preventive maintenance schedule.
To test for a leaky toilet, dye the water in the reservoir, and wait to see if any dye leaks into the bowl on its own. If it does, your toilet is leaking, and it is time to replace the gaskets.
Some leaks are so large, they are audible.
Issues and Concerns
The earliest low-flow toilets got a bad reputation because they didn't work well, often requiring double flushing. These early design problems have been overcome, and low-flow models are now just as effective as old-style high volume toilets.
Veritec MaP Report http://www.veritec.ca, click on "Product Testing"
California Urban Water Conservation Council, rating of HETs http://www.cuwcc.org/WorkArea/showcontent.aspx?id=8076
Savings are based on 1.6 GPF toilets.
Savings = (Flow.pre - Flow.post) x (Uses per year) x (Fixture Load Factor)
(15LPF - 6LPF) x (3 uses/person/day) x (250 people) x (250 days/year) x (0.001m³/L)
= 1687.5 m³/year