Health services aiming to reduce water use should consider:
- the risk hierarchy for water conservation and reuse
- other health and safety risks, especially in relation to infection control.
A project screening assessment should consider the risk hierarchy, potential volumes to be saved and project costs. The emphasis is on undertaking the lowest risk and highest value projects ahead of medium-risk and more costly projects.
Figure 1: The risk hierarchy for water conservation and recycling projects
Further information is available on project screening in the Guidelines for water re-use and recycling in Victorian healthcare facilities.
Ten things you can do
While every facility is different, there are a number of common measures you can take to reduce use of potable water.
A water audit is generally the first step, as it will identify the most appropriate water-saving opportunities in terms of cost versus savings, thus enabling projects to be prioritised.
Particular care must be taken to assess the risks and benefits associated with proposed projects.
1. Conduct a water audit
A detailed water audit identifies uses, usage patterns, and quantifies potential water-saving opportunities. The Department of Health has developed a Water management plan template.
2. Install data-logging water meters
Installing data-logging water meters on incoming water enables ongoing monitoring. This helps to identify trends, usage patterns and leaks. The data loggers are usually sourced from your water retailer.
3. Check for leaks
A significant amount of infrastructure is ageing and prone to leaks. As much of it is underground, leaks are not always easily identified. Data-logging meters at the boundary are useful because out-of-hours data (when water use is expected to be very low) becomes readily available.
4. Install sub-metering
Metering of separate buildings and key processes enables usage and trends to be monitored throughout the site. The use of meters that are connected to a building management system (BMS) enables easy data collection.
5. Install flow restrictors
A number of fixtures (for example, hand basins, sinks and wash troughs) have unregulated water flows that may lead to higher use. Installing flow restrictors with balanced pressure is generally a cost-effective way to reduce water use without affecting functional requirements.
6. Install dual-flush toilets
Toilet flushing may account for around 20 per cent of total usage. Dual-flush cisterns need to be correctly matched with pans or functionality may be compromised. The use of waterless urinals may also be considered.
7. Reclaim or recycle water from sterilisers
A significant amount of water is used through cooling systems and vacuum pumps associated with high pre-vac sterilisers. Water may be reclaimed for non-potable uses or cooled for re-use via chilled water, cooling towers or other means. The potential for increased energy use needs to be considered.
8. Reclaim reverse-osmosis reject water
Reject water from reverse-osmosis machines may be reclaimed for non-potable uses (for example, flushing, steriliser cooling, irrigation). Newer machines reject less water, so opportunities may be limited.
9. Install low-flush pan sanitisers
Low-flush pan sanitisers can reduce both water and energy consumption.
10. Three-pipe systems enable non-potable water to be used where practicable
Three-pipe systems comprise cold water, hot water and non-potable water reticulation, thus enabling the use of non-potable water (such as from other processes, rainwater or bores) to be used where practicable. Particular care needs to be taken to avoid any cross-connections and avoiding the creation of other potential environmental issues.
Risk assessments are required to minimise potential hazards.
The use of reclaimed water for non-potable processes may be limited by the distance between the process generating the waste water and the proposed use. For example, a practical use for steriliser waste water is toilet flushing.
However, if the steriliser is a long way from the flusher tank, the capital cost of the pipework may make the project unviable on economic grounds.
Blockages may occur where waste pipes are damaged internally or have a low gradient.