FEATURE
The foyer of the CBW complex in Melbourne. The new black?
Despite their high capital cost and maintenance requirements, blackwater treatment systems are playing a growing role in Australia’s new building stock, improving the water efficiency while also reducing the strain on mains sewer systems. Sean McGowan reports.
The construction industry continues vacuum flush toilets have an exceptionally Greywater and blackwater treatment to push the boundaries of design in low water use, as low as 0.5 litres per flush, is therefore normally considered when order to reduce the impact of the built compared to a water saving toilet of 3 to opportunities for the reuse of onsite environment on natural resources. 4.5 litres per flush,” he explains. water are also exhausted. Yet whatever downsides may exist are often countered And though energy efficiency in “Tapware is now available which uses by the weighting ESD assessment tools commercial buildings receives more just 1.7 litres per minute, against 6 litres such as Green Star place on water savings attention, water efficiency is also moving per minute, which is typical of a 5 star and waste reductions, around which along at a rapid rate, as technology plays WELS-rated fitting.” modern-day BWT systems are designed. a greater role in the water protocol of reduce, reuse and recycle. We believe that where Inside blackwater Like any major piece of kit, blackwater a good level of water treatment (BWT) systems or plants Onsite wastewater treatment systems in treatment infrastructure is (BWTPs) are not suitable in every buildings typically treat either waste from application, and bring with them a series available, as is the case baths, showers, hand basins, kitchenettes of significant potential downsides. This in many major Australian and other wastewater streams, known as is why professionals such as Roger Kluske, cities, this technology greywater, or all sewage including toilet M.AIRAH, associate and sustainability should not be a first choice and urinal waste, known as blackwater. consultant at Umow Lai, believe ’ This treatment is achieved by a adherence to the water protocol Once water consumption has been combination of chemical, physical or remains the most efficient method optimised, designers should turn their biological processes to successfully treat of water management. attention to areas of harvest and/or reuse the wastewater to a suitable standard for “Of course Umow Lai has designed says Kluske, which typically includes reuse in a range of non-drinking water BWT plants for our clients,” Kluske says. rainwater and stormwater collection. applications, including for flushing “However, we believe that where a good toilets, garden irrigation and in heat- “In some circumstances, it may also be level of water treatment infrastructure rejection systems. worth examining greywater capture and is available, as is the case in many major reuse, but designers should be aware of Although the treatment processes of Australian cities, this technology should regulations around its storage.” greywater and blackwater can be similar, not be a first choice.” greywater treatment systems can require Naturally, the capture and reuse of Rather, he says, opportunities for a duplicate sanitary plumbing system and rainwater and stormwater is the easier, reductions in potable water use should may also suffer from a lack of water, with cheaper and less energy-intensive option, first be exhausted through the use of larger quantities of blackwater due largely and is now considered standard for all but innovative fittings and fixtures. to toilet and urinal flushing. the rarest building designs. Greywater “There are great advancements in water reuse without treatment is also possible According to sustainability consultant saving fittings and fixtures. For example, for some purposes. Nicki Colls, a greywater system is most
22 Ecolibrium • MARCH 2011 Designed by architect Denton Corker Marshall, the new Sydney Water HQ at Parramatta aims to reduce water use by 75 per cent and waste water to sewer by up to 90 per cent compared with an equivalent commercial office building. It is the first government building in New South Wales to incorporate a blackwater treatment plant. The BWT plant collects and treats waste water from cooling towers, showers, sinks, basins, toilets, urinals as well as rainwater, for re-use for irrigation, toilet flushing, fire system testing and cooling towers. The building has achieved 5 star Green Star Office Design and As-Built Rating. Picture: Nicholas Lee. FEATURE “The INDUSTRIAL
water such cooling systems require, AIR-VOLUTION particularly on very hot days. According to Norman Disney & Young associate Ben Castle, the Corner has begun” Burke and William (CBW) complex in Melbourne is a prime example of where FrAnk Seeley Am a BWT system has been used for this purpose. “We designed these buildings to incorporate a 100 kL-per-day BWT plant, treating sewage from two office buildings atop a common podium,” Castle explains. “Here, recycled water is supplied for toilet flushing and cooling tower use. A 5 star Design rating has been achieved under the Green Star Office Design rating system.” The WRAMS (water reclamation and management scheme) system at Sydney INDUSTRIAL COMMERCIAL Olympic Park takes the technology to a district scale, providing up to 7ML of recycled wastewater daily to multiple buildings linked to the system across the The award-winning Climate Wizard has set a new benchmark in air conditioning, site, as well as to the surrounding suburbs delivering cooling performance that can rival refrigerated systems, but using up to of Rhodes and Newington. In doing so, 80 per cent less energy. it achieves even greater efficiencies than stand-alone systems. Climate Wizard uses the natural process of evaporation to cool, but employs revolutionary technology that cools without adding moisture to the air. It can be used on its Economics and own (stand-alone) or in conjunction with existing or new other motivations refrigerated systems. Although any building design that The 1 Bligh St building being constructed by Grocon in Sydney reduces mains water demand and reduces Braemar evaporative coolers have been employs blackwater treatment. the stress on the civic sewer system should Australia’s number one choice for be applauded in the same manner as commercial and heavy industrial cooling attractive within multi-residential common method being membrane those that reduce electrical grid demand, buildings, given the large, constant bioreactors (MBR), although a variety for more than 40 years. For reliable, low the economics of such design decisions supply of bathroom wastewater and maintenance cooling with even lower of other established techniques exist. remain at opposite ends of the ledger. high non-potable water demands. running costs, year after year, Braemar An MBR system, for instance, is used “Blackwater treatment plants are coolers are the proven performers. “In contrast, rainwater reuse systems are at the Vancouver Convention Centre in expensive to design and construct, more often considered when there is a British Columbia, Canada to treat the on top of the ongoing maintenance smaller, less reliable source of greywater building’s sewage, providing 80 per cent requirement,” says Castle. “With water and large, non-potable water demands, of the water needs for toilet flushing in being so inexpensive, there is no payback such as commercial office buildings,” Colls the building and supplemental water for on investment if it is looked at purely natur arth says, adding that sites with a small footprint irrigating its 24,280 sq m living roof. from the perspective of the potable water al air conditioning that is out of this world, but won’t cost the e and consequently less potential to capture reduction.” After primary treatment, tertiary and reuse rainwater are those that typically AwArdS InduStrIAl & CommerCIAl ApplICAtIonS consider onsite recycling of wastewater to treatment disinfects the resulting water, The capital cost of a BWT system reduce potable water demand. and can include one or several techniques depends on its size, design, method 2009 GreenPlumbers Energy Efficient Product of the Year • Data centres • Community halls including flocculation, filtration, UV of treatment and local regulatory 2010 Airconditioning, Refrigeration & Building Services Trade Expo • Warehouses • Leisure centres To achieve a suitable standard of recycled irradiation, chlorination, ozonation, requirements, but Castle says to expect (ARBS) HVAC Product Excellence Award water from such systems, Colls says three • Supermarkets and retail stores • Sporting stadiums electro-dialysis and reverse osmosis. an initial outlay of at least $500,000 2010 Southern Adelaide Innovation Award for Innovation in an stages of treatment are typically employed. for a large office building project. Environmental Product • Food processing plants • Manufacturing faculties This water can then be used for a range 2010 Gold GAIA Award at the Big 5 International Show, Dubai • Schools • Offices Primary treatment uses physical of purposes, including heating and However, Colls reports in her paper, Black separation to remove larger cooling systems, which is often an and Greywater Reuse: The Real Results, contaminants, either via filters, screens, attractive option where buildings have presented at AIRAH’s Achieving the centrifuges or settling. A secondary very high cooling demand. Green Dream conference last year, that treatment uses biological processes to of seven BWT systems investigated remove soluble nutrients through either In contrast, greywater treatment systems (commissioned between 2004 and 2010 oxidisation or conversion, with the most typically can’t supply the volumes of and ranging in capacity from 1.2kL to Backed by the experience and technical expertise of Seeley International, Australia’s largest and leading air conditioning manufacturer
24 Ecolibrium • MARCH 2011 (08) 8328 3850 seeleyinternational.com [email protected]
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100kL), the average total capital cost was Although Green Star tools do not most locations, and water treatment $34,000 per kL capacity. specifically reward onsite treatment and is a common strategy to minimise reuse of BWT systems, the rating system consumption,” Morton says. Associated maintenance regimes include does award points for potable water daily and weekly inspections, quality savings (water category) and reduced “While many projects avoid them, other testing and reporting, as well as periodic discharge to the sewer (emissions). Green Star-rated buildings have used cleaning of the membranes or other BWT systems to dramatically cut water screens and general maintenance of With both of these categories holding use and thereby acquire a considerable pumps and sensors. a high weighting within the tool, a number of Green Star credits.” significant incentive exists for developers Though Colls’ study found the average to consider onsite BWT in a bid to achieve maintenance cost of the systems 5 and 6 star ratings. Variations investigated to be $2,000 per kL capacity, others report the cost of outsourced and alternatives maintenance to be upwards of $20,000 The main motivation for Along with BWT systems serving single per annum depending on the capacity installing such systems is buildings, the promise of increased and type of treatment technology used. typically not a financial one. efficiency in district-type schemes such as the one in operation at Sydney Castle says a “clean in place” (CIP) is Rather, it is either to ensure Olympic Park, is sure to spur future typically conducted on the membrane security of supply, or to system two to four times a year. And implementation where Greenfield sites while the lifespan of membranes demonstrate corporate are concerned. responsibility. can be up to seven years, other But efficiency gains can also be achieved hardware such as UV lamps are ’ by onsite systems, such as those where likely to be replaced more often. Hannah Morton, senior ESD consultant sewer mining has been implemented, with Cundall in Sydney, says that while “Systems are always designed so that they projects may discount BWT due to their despite reported start-up issues on some can be removed from service without cost and water-quality concerns, there are projects. affecting ongoing operation of the many examples of buildings having taken An excellent example of this design building by diverting building wastewater this approach and employed BWT with to sewer and automatic potable water variation is 1 Bligh Street, Sydney’s varying degrees of success. back-up,” he adds. first high-rise commercial office to These include high-profile examples incorporate a BWT system. Here, the Capital costs vary according to the such as Melbourne’s CBW Complex; BWT onsite system will not only treat technology of the system’s treatment. Sydney’s 1 Bligh Street, Workplace6 and blackwater produced by the Grocon-built A 100kL/day system such as the one the recently completed Sydney Water building, but also “mine” or harvest incorporated into the design of the HQ; and larger mixed-use sites such as sewage from the nearby sewerage main. Warranty solutions… CWB complex remains a very expensive Sydney Airport, Macquarie University proposition, requiring other motivating Although this requires a larger capacity and the University of Melbourne factors to drive the decision. system, it will save 100,000 litres of potable Economics and Commerce Building. it’s as easy as JNG water daily, and meet 90 per cent of the “The main motivation for installing such “Water savings are an important building’s water demand, contributing to systems is typically not a financial one,” 9 component of Green Star ratings in its 6 star Green Star rating. Save costs says Colls. “Rather, it is either to ensure 9 security of supply, or to demonstrate Focus on other business goals corporate responsibility.” 9 Improve your warranty management She says despite the high capital cost and 5 lessons about blackwater treatment 9 Enhance your brand reputation lack of a current payback, the uptake and 9 interest in onsite treatment and reuse of 1. Apply the water protocol: reduce, reuse, recycle. First, exhaust all Warehousing wastewater has increased significantly opportunities for reductions in potable water use and onsite rainwater in Australia over the past five years. harvesting. JNG understands the challenges of warranty management and “The increased demand for these systems 2. Greywater treatment systems are most suitable in multi-residential spare parts distribution. relates to greater community awareness of buildings due to the large, constant supply of bathroom wastewater and high non-potable water demands. potable water scarcity as a result of drought We allow you to not only save costs, but focus on other and the subsequent water restrictions 3. Blackwater treatment systems are suited to buildings with high non- and regulatory requirements imposed, potable water demands and where the building footprint limits the business goals. such as the requirement for 3 Star WELS volume of rainwater able to be harvested and stored. minimum-rated tapware,” Colls says. 4. The end use of the recycled water from BWT systems heavily See why other leading manufacturers choose JNG to manage influences the treatment process required. The exact treatment train “Government tenants, local authorities employed should be subject to risk assessment. this important aspect of their business. and development authorities have helped move the market in the direction 5. Consider a district-type system, sewer mining or systems incorporating of increased water efficiency, as do anaerobic digestion, as they can improve efficiencies and contribute to a voluntary ESD assessment tools such as payback beyond water reuse and sewer discharge reductions. Green Star.” Authorised Spare Parts Distributor of: 1300 553 000 26 Ecolibrium • MARCH 2011 jngairconditioning.com.au FEATURE
Water vision at the Visionaire coupled with a semi-permeable membrane to help with water purification. What’s new in this case is the A 35-storey condominium application of sewage treatment technology coupled with a semi-permeable membrane to help with water tower in New York City purification. recycles wastewater At the Visionaire, potable water is supplied for personal for onsite reuse, writes use, while rainwater and blackwater are collected and Jerry Yudelson. treated, then reused onsite. So what lessons were learned on the project? The burden on infrastructure such as sewers in Manhattan “This is the third building in New York City where the means that without onsite developers have done a blackwater treatment system,” sewage treatment, the 35-storey says John An, who helped design the Visionaire. luxury condominium the Visionaire would never have received the necessary “One of the lessons learned – and it’s not specific to this permits to be built. building – was that initially the treated blackwater, while it’s clean, has a higher salinity content. So when they were The LEED Platinum-certified project (roughly the using the treated water in the cooling towers, they found equivalent of 6 star Green Star) treats all wastewater that there was damage to some of the equipment over from the building in the basement, and recycles it for site time. On this project, they changed the water balance so irrigation, toilet flushing and cooling tower makeup water. more of the stormwater and greywater gets mixed into Building sewage is collected in tanks that occupy about the blackwater treatment system so salinity is diluted. On a quarter of the basement’s footprint and is cleaned occasion, potable water could be put in as well. The lesson biologically to a potable water standard. The building is learned: you can’t take treated blackwater and dump it into expected to reduce potable water demand by 40 per cent the cooling tower without dilution.” below the norm for a similar building. Taken from Dry Run: Preventing the Next Urban Water The chosen solution was to use a membrane bioreactor, Crisis by Jerry Yudelson, New Society Publishers, which uses standard wastewater treatment technology Canada, 2010.
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Authorised Spare Parts Distributor of: 1300 553 000 jngairconditioning.com.au FEATURE
Kluske believes where blackwater is to Preparing for assign great value on reducing the impact be treated, the use of anaerobic digestion of their building on water and sewer should be strongly considered. a drier future infrastructure.” Despite the recent above-average rainfall He says it not only treats sewerage and floods ending drought in the eastern The trend towards zero-emission but also provides additional benefits and southern states for the time being, building stock is also likely to influence beyond water reuse and sewer discharge the science remains committed to a drier the future of wastewater treatment reductions. future for much of Australia. systems, allowing buildings to take ™ another step closer to self-sufficiency RoboClean Number One for duct cleaning in Australia “The use of anaerobic digestion doesn’t With water security a continuing priority have the same high levels of energy by providing non-potable water, for both government and business, as well as dealing with sewage onsite. consumption (as other secondary systems such as BWT are an important First in AHU & Air Duct Clean in the Southern Hemisphere, since 1993. treatments), and as an added benefit addition to the suite of water conservation Colls believes the reuse of wastewater produces a low-value fuel as a by- methods at our disposal. However, the for cooling is set to become one of the product,” he explains. costs associated with implementation most popular and effective applications Major Air Duct installations – 17 years servicing “This by-product, methane and sulphur may mean that, for the time being at least, of BWT systems, and with desalination Victoria and offering an Australia-wide service dioxide plus impurities which our its prevalence remains closely tied to the likely to push up prices of mains water American friends call ‘swamp gas’, can future of ESD rating tools. supply, this may provide an extra Have a robo-cam inspect be burned as a super-clean energy source This is a view shared by Castle. incentive for developers. directly for domestic hot water, or in a co/ “Technology improvements are also your dirty air ducts today! trigeneration system with excellent results.” “BWT plants will continue to be part of new commercial buildings while Green decreasing upfront and ongoing running Although such a system relies on a Star ratings in their current form are costs,” Colls says. “And of course La Niña significantly large volume of blackwater important to industry,” he says. “They won’t last forever.” ❚ FREE – Full THE SOLUTION TO to be stored and processed, its attract a high cost and maintenance HVAC Ductwork real advantage lies in the avenues requirement, so owners of buildings THE TOUGHEST HIDDEN to a financial payback. that incorporate them are those that Inspection 03 9465 4300 HAZARDS IN BUILDINGS: CALL TODAY! RoboClean™ identifies & eliminates: Legionnaires’ Disease carriers, Bacteria, Micro-organisms, FACT: There are an estimated 30,000 Viruses, Dust Mites, Mildew, Lint, Pollen, Pollutants, Toxic Fallout, Soot, Black Rain, Grease, Grime And MUCH MORE. cooling towers operating in Australia. RoboClean™ specialise in: · Air Duct HVAC Duct Work & Coil Condensate FACT: Cooling towers can use between Cleaning. Rusts, Corrosion, Fan & Duct Restoration 5,000 and 10,000 litres per day. · Indoor Air Quality Solutions / Robotic Video Inspection · Air Handling Unit & Component Cleaning, You can do the maths! We did and the result is a one of a kind Air Vents and Grills cooling tower water efficiency calculator available online. · Energy Saving Management on (AHU) Apply NANO Tech · Pre Filter Fresh Air Intake & HVAC Hygiene Assessments www.ctwec.com www.roboclean.com.au
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