While a minimum level of pressure will be maintained for all properties, for some businesses, the difference may mean their existing fire protection systems, such as sprinklers, will no longer have enough pressure to effectively combat a fire or comply with building codes. In many parts of Australia, water authorities provide consumers with water pressure that is as much as five or 10 times the minimum government standard. This in turn places pressure on water mains. Sydney Water hopes that through pressure reduction and leakage management it will be able to save up to 33 billion litres of water per annum by 2015, and in today’s environment, this difference is crucial.
Pressure reduction will mainly occur in areas that already have substantially higher pressure than other parts of Sydney. In Australia, there is a minimum government standard per property of 15 metres, which means enough pressure to support a column of water 15 metres high, or roughly 150 kPa. Some parts of Sydney, such as Cronulla, have well over 1000 kPa.
Denis Armstrong, principal at consulting engineering firm Armstrong, says: “Now a lot of buildings will not comply with the current building codes. In city areas, buildings cover boundary to boundary and are being forced to put pumps and tanks in. This can be expensive because you have to chop floors up. This reduction in water pressure means you have to change the design so you can install tanks and pumps. But changes are happening slowly.”
Any businesses that will be affected will receive a document from the Fire Protection Association Australia (FPAA) outlining the changes and how they will be affected. They will also receive advice from Sydney Water 12 months in advance of any changes.
Ashley White from Davey says that while the company has not yet needed to retrofit any pumps into Australian businesses due to pressure reduction, there is a huge demand for booster pumps overseas. “Pressure reduction is happening everywhere - it’s very common overseas,” he says. He believes that while we are in the early stages of pressure reduction here, it is only a matter of time before businesses are forced to install pumps to maintain water pressure. At this stage, most Davey pumps sold are for domestic use, but once the pressure reduction process is completed, White anticipates it will be contracted to retrofit pumps into commercial buildings as well.
Greg Kennett from JBA Consulting Engineers says that some high-rise developments have been affected. “Multi-storey systems no longer comply because they don’t have a booster system. What complied five years ago doesn’t comply now. What is happening with a multi-storey building is they tend to recommend installation of a booster pump,” he says.
Pressure reduction has been underway in Victoria’s Yarra Valley for around two years, and many large developments have been affected. According to a fire industry representative, sites such as car parks, schools, nursing homes and shopping centres have had sprinkler systems that no longer meet flow requirements. "We worked on a large nursing home that had a sprinkler system. We had to put in a pump and a tank because the water supply no longer met the minimum flow requirements," the representative says.
Fire systems don’t require complicated variable speed pumps as they only need a single speed to maintain enough pressure in an emergency, and in general, simpler pumps are cheaper and more reliable. A diesel powered pump is also cheaper than an electric pump and a better option due to the large amount of power required and the possibility of electrical failure in a fire. These types of pumps are available from specialist pump or water product suppliers such as Davey, Above All Tanks and Pumps and Prime Pumps. Many developers also use engineering companies such as Armstrong, JBA Consulting Engineers and Galvin Engineering to install the systems.
Commercial booster pumps are around two metres by three metres and also require a clearance around them, which generally means they need a dedicated room on the ground floor or basement. Pumps capable of servicing a multi-storey development range from around $10,000 to $40,000, and installation costs vary depending on the site, but can be from as little as $5,000 up to $25,000 or more.
Because reduced pressure also means reduced flow, many systems won’t have access to enough water in a fire so some properties will also need to install water tanks. To meet building code requirements, these tanks will need to be around 50,000 litres to 100,000 litres or more, which means roughly an eight metre diameter tank. This means another $20,000 to $30,000 and again, installation costs, depending on the site. In some cases the building slab and floors will have to be dug up and re-set, which can run costs well into the tens of thousands.
For smaller businesses that may be affected, the cost will be substantially less, especially if no tank is required. Domestic size pumps start from as little as $1,000 and if a tank is required, a 25,000 litre tank may be sufficient.
For future projects, building specifiers may need to take into account the potential for pressure reduction to occur and base plans on the minimum pressure requirements rather than the actual pressures currently available. This means setting aside a dedicated area for pumps and tanks or even including a booster pump, regardless of whether it is initially required or not. Pressure reduction is a long-term project and it is likely that all metropolitan areas will eventually be reduced to a consistent, average pressure.
