Part 3 Alternative water sources

Part 3 of Best practice guidelines for water conservation in commercial office buildings and shopping centres provides advice on alternative water sources that may be used in commercial buildings.

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Chapter 20 Rainwater

Using rainwater is an excellent way to reduce demand on mains drinking water. Rainwater collected from roofs generally has low levels of pollutants, especially if a first flush diverter is installed. This makes any required treatment relatively simple and inexpensive.

The bigger and cleaner your roof catchment area, the more likely it is that you will be able to implement an effective rainwater reuse scheme.

Using rainwater NSW Health does not as toilet flushing or cooling recommend using rainwater tower makeup. Frequent use of Rainwater can be used to replace for drinking and cooking when rainwater also maintains better drinking water for a range of an alternative mains water water quality. uses including water features, source is available. Guidelines toilet flushing, water heating are available in the document systems, garden irrigation How much rainwater Rainwater Tanks where a Public and outdoor cleaning. Most can you catch? Supply is Available published by rainwater has very low levels of NSW Health. Before implementing any large dissolved solids that can make scale rainwater collection system, it well suited for cooling towers. To maximise the amount of you need to be aware of the size Make sure you are aware of water and money you save with of your catchment and the likely the properties of rainwater you a rainwater tank, it’s important annual rainfall you will receive. collect from your site before you that you maximise your use of use it in cooling towers. rainwater. This can be achieved by using rainwater where it will be used frequently such

Photograph 10 – Rainwater captured in tanks at Investa’s 73 Miller Street building in North Sydney, is used to irrigate gardens on the building’s rooftop and balconies.

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You can refer to the Australian Rainwater quality A ‘first flush device’ will also Plumbers must complete all Costs and benefits of Bureau of Meteorology’s improve rainwater quality. The work in accordance with the rainwater tanks The quality of rainwater website at www.bom.gov.au device sits between the roof NSW Code of Practice Plumbing collected will depend on the Rainwater harvesting is a popular for data about average annual downpipe and the rainwater and Drainage and follow the location in which rainfall way to conserve drinking water, rainfall and mean days of rain storage tank and will dispose specific technical requirements occurs, as well as the surface although it is usually less cost for many locations in Sydney. of the first rainfall runoff for rainwater tank plumbing it falls onto and the standard effective than other measures collected by your roof. Because that are detailed in Guidelines of storage tanks. Rainfall in an for reducing water consumption, You can calculate the theoretical the first flush contains a higher for the Installation of Rainwater industrial area is more likely such as leak reduction and maximum rainfall that can concentration of pollutants, a Tanks on Residential Properties, to collect airborne pollutants improved efficiency. However, be captured by multiplying properly sized first flush diverter Part 1 Plumbing requirements. and roof catchment areas are rainwater tanks are easy to your roof catchment area is very effective at improving the more likely to be polluted with install and a strong visual (in metres) by the average quality of collected rainwater. For more information, settled particulate matter. symbol for water conservation. annual rainfall in metres. contact Sydney Water’s Use mesh covers and strainers Plumbing Policy, Standards Rainwater collected from paved Rainwater is not governed by It is likely that the amount of on the inlet and overflow of and Regulation Group at: areas including carparks and water restrictions and can be rainfall you can capture in a the tank to prevent mosquitoes roads is typically referred to [email protected] freely harvested to irrigate given year will be up to 20 per and other insects from getting as stormwater and contains parks and gardens. Rainwater cent less than the theoretical into the tank and breeding. This You should also contact your significantly higher levels harvesting also reduces maximum because of losses will improve water quality and local council to discuss the of pollutants. The capture, stormwater discharges from from evaporation in small rainfall prevent your tanks from causing regulations that apply to treatment and reuse of commercial sites, which reduces events, infiltration into roof a public health nuisance. the installation of rainwater stormwater is covered in stormwater flows into the materials, overflows from gutters tanks, stormwater reuse Chapter 21 of these guidelines. local environment and reduces and tanks during heavy storms systems and greywater or Plumbing requirements stormwater volumes during and losses to first flush devices. black water reuse systems. The roofs of commercial and approvals rainfall. It can also be a visible buildings may collect For a rough calculation of how If your tank is going to require In New South Wales, property and low risk measure when contaminants like dust, leaves, much water you may be able to top up from mains water, which owners can install tanks of compared to reuse options. vegetation, bird faeces and save with a tank of a given size, is likely if tank water is likely up to 10,000 litres without occasionally dead animals. you can use online calculators at to be used for needs such as development approval – Equipment and cleaning Keeping roofs clean with regular toilet flushing or cooling tower providing conditions such as https://egrants.com.au/ maintenance will improve the Keep your roof catchment operations, you will need to siting, installation of first flush watertankmodel/index.asp quality of collected rainwater, clean, install an adequately comply with backflow prevention diverters, noise mitigation and reduce the likelihood that sized first flush diverter and To more accurately model containment requirements and mosquito control are covered. gutters and collection systems remove sludge from tanks every tank sizes, you need to use install a backflow prevention Larger tanks or tanks that do not get blocked and reduce two to three years. Your tank daily rainfall data, understand device at the property meter to comply with these conditions the amount of treatment water should remain quite your average daily water use protect the mains supply. usually require local council that will be required. clean and you will not need and incorporate variables development approval. complex treatment systems. such as temperature and seasonal variability.

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To use tankwater, you usually Converting onsite • it might be necessary to treat need to install good quality detention tanks stormwater from some areas pumps to ensure adequate before it is diverted to your Many commercial buildings operating pressure. You also storage tanks. If you have more have been constructed with need a reliable device to than one OSD tank, it might large on-site detention (OSD) switch between rainwater be possible to separate your tanks for stormwater. These and mains water supply. It is stormwater and rainwater tanks are designed to capture common for poor quality and collection so that you can rainwater and stormwater after badly maintained pumps to use each water source for heavy rain, and slowly release it fail and this can jeopardise purposes appropriate for to the main council stormwater the success of your rainwater their different quality. system so these systems do harvesting operations. not become overloaded. Useful documents Your plumbing contractor or There is increasing interest in hydraulic engineer can advise NSW Health Private Water converting these tanks to storage on the costs and installation Supply Guidelines 2007, NSW tanks. You should consider: of this equipment. Health, www.health.nsw.gov. au/public-health/ehb/water/ • using your OSD tanks may You will need to clean your tank private_supplies.html make design easy because regularly to remove accumulated rainwater collection has sediments. The technique used Guidance on the Use of been centralised, i.e. there will depend on the type of tank Rainwater Tanks 2004, is little need to consolidate you have installed. Advice on Environmental Health downpipes that drain how to clean tanks is provided Monograph, enHealth Council, different parts of the roof in ‘Useful documents’ section of http://enhealth.nphp.gov.au/ council/pubs/documents/ this chapter. • OSD tanks will often also rainwater_tanks.pdf take stormwater from paved common areas (like shopping Use of Rainwater Tanks Where a centre forecourts), footpaths, Public Water Supply is Available, Case Study carparks and internal roads. June 2007, GL2008-09, NSW Lend Lease Retail This is likely to increase Health, www.health.nsw.gov.au/ pollutants including oils and policies/gl/2007/GL2007_ greases in the captured water, Lend Lease Retail operates Macarthur Square Shopping Centre in Campbelltown, in the south 009.html which may reduce the uses west of Sydney. Lend Lease is collecting rainwater from the centre’s roof, storing it in a 250 kilolitre of this water, or necessitate underground tank and using it for toilet flushing and garden irrigation. additional treatment Photograph 13 – Part of the extensive roof top area at Lend Leases’ Macarthur Square in Campbelltown. This roof top is a catchment for 250 kilolitres of rainwater storage.

101 102 3 103 Chapter 20–Rainwater operate independently mainswater of forthe year. of 80percent cool airbeforethe building’s enters it airintakes. The sitehasbeendesignedby Watermark Architecture to &Interiors Photograph 14–Blackmores’ newheadoffice at Warriewood on Sydney’s beachesusesa topre-waterbody northern building entrance. water features the near stormwater is used to fill Captured rainwater and water asmuchpossible. reduce reliance on mains by the company’s desire to was strongly influenced The design of the building the staff swimmingpool. towers, irrigation and to fill rainwater for drinking, cooling Blackmores is harvesting constructing anewbuildingdesignedby Watermark Architecture &Interiors. northern beaches. Through development and project managers, Ray White Projects, it is It is constructing a new head office building and distribution centre in Warriewood on Sydney’s Blackmoresthe leadingAustralian isoneof manufacturers natural of healthsupplements. Blackmores Case study

on the site.on have beenreconstructed capturedthat bywetlands Stormwater overflow is treated andreused. is alsocaptured, Cooling tower blowdown on itscooling systems. reducing demand further airintake, of the point aroundthe buildingat temperature air ambient This waterbody reduces forthe year. of 80percent independent of mains water entire site is designed to be cooling load – but the hasahigher because it higher demandfor water and distribution centre has the year. The manufacturing mains water for 97 per cent of operate independently of The office building can

Figure 18–Rainwater, stormwater, greywater andblackwater are the classifiedaccording to water’s source. t�

t� t�t� Chapter 20–Rainwater 104 3 3 Chapter 21 – Stormwater reuse 3

Chapter 21 Stormwater reuse

Rainwater that has been collected from outside areas such as paving, footpaths, roads and car parks is generally called stormwater. Harvested stormwater can be used to flush toilets, clean down carparking areas and irrigate garden areas.

As well as reducing your use irrigation of gardens and parks, In some developments, of mains drinking water, water features, vehicle and irrigation is used as a method of using stormwater will reduce outside area washing. In some stormwater treatment because the amount of stormwater areas where groundwater is plants and soil will remove discharged from your site and extracted, captured stormwater nutrients and some suspended reduce your site’s impact on the can be used to recharge aquifers. solids. Once water is recollected surrounding environment. from irrigated areas it can be If you want to use stormwater used for more sensitive uses. The type of technology used for uses that have a higher to harvest, store and treat chance of human contact How much stormwater stormwater will depend on you will need to take more can you capture? specific site conditions including precautions to keep your the size of your site, expected stormwater catchment clean The amount of stormwater that local rainfall, the level of likely and treat stored water properly. can be captured depends on stormwater pollution, the type of It is important to understand annual rainfall and catchment soils on-site and the sensitivity of the quality of your source water size. Precise calculations on downstream environments. and design a treatment and how much you can capture will management system that will depend on the type of ground surfaces in your stormwater Using stormwater produce water suitable for your end use. catchments, the aspect and slope Captured and treated of your site and the amount of stormwater is often used for rain that falls in each rain event.

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Campus style buildings and Keeping catchment areas clean Consult your local council about suburban shopping centres can improve stormwater quality. regulations that apply to the have large sites and are more Installing trash racks or gross installation of stormwater likely to be able to capture pollutant traps can be expensive storage dams or tanks, treatment and reuse stormwater than but will reduce pollutant loads. equipment and alterations to high rise commercial buildings Regular street sweeping or onsite detention systems. on relatively small sites. litter patrols can also remove pollutants. Making sure that Costs and advantages Refer to the Department of operations on your site, such as Environment and Climate garbage storage and collection Costs of stormwater capture Change NSW website at and building and excavation include pre treatment, piping, Case study www.environment.nsw.gov. works are well managed, will collection, treatment and the Kogarah Town Square au for information on how reduce the chances of harmful reticulation of treated water. much stormwater you can stormwater contamination. Because stormwater catchments The Kogarah Town Square development comprises 193 residential apartments, 4,628 square capture and reuse in urban and stormwater quality vary so metres of commercial and retail outlets and a town square with underground parking. The water areas in New South Wales under much, cost calculations need management system in Kogarah Town Square was designed in a holistic water cycle management Plumbing requirements harvestable rights orders. to be made for each project. approach, focusing on water reuse and efficiency. If you use stormwater for The three main principles From the impervious areas, From the roofs, rainwater is purposes that may require Reusing stormwater can Stormwater quality under which the Kogarah Town stormwater passes through collected in a storage tank top up from mains water you reduce other development and Square project was developed a gross pollutant trap that under the public car park. The In many commercial buildings, need to comply with backflow maintenance costs, such as: as a best practice example filters out the litter and large water passes through a screen stormwater catchments prevention containment of urban water collection, pollutants. The water is then filter and is pumped for toilet will be heavily used by requirements. You should • reduce the required volume of treatment and reuse are: collected in a storage tank and flushing, car washing and into people, pets and vehicles. install a backflow prevention stormwater discharge pipes pumped to irrigate landscape the water feature in the Town device at the property meter • reduce or eliminate the need 1. capturing stormwater areas. This saves up to 2,130 Square. This gives a savings of Stormwater can be to protect the mains supply. contaminated by oils and grease, for onsite detention systems from impervious areas kilolitres of potable water a approximately 5,789 kilolitres litter and harmful pathogens. Plumbers should complete 2. collecting rainwater year. In addition, the landscape of potable water a year. • reduce the need to install As the quality of stormwater all work in accordance with from the roofs area acts as a filter for the depends on the catchment it is and maintain ’end of pipe‘ water, removing the excess Residential and commercial the NSW Code of Practice 3. reducing the demand of sourced from, it can be easier treatment systems, such nutrients and fine particles. properties are fitted with Plumbing and Drainage. potable water through to reuse stormwater if heavily as gross pollutant traps. The filtered water is collected water efficient devices water conservation. polluted catchment areas – such Please refer to Sydney Water’s and stored in a separate tank such as flow restricted Case studies of stormwater as car parks – are excluded. Plumbing Policy, Standards Eighty per cent of all water and used as a primary top up taps, 3 star rated showers, capture in different and Regulation Group that falls on the site in a year supply for the other tanks. dual flush toilets, efficient types of developments for more information. (7,854 kilolitres) is reused. urinals and dishwashers. are described below. Photograph 15 – Water features at Kogarah Town Square are supplied with water from the site’s rainwater and stormwater collection system.

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Chapter 22 Groundwater

In some cases groundwater, sometimes known as bore water, may be a feasible alternative water source.

Accessing and managing Details of the embargo the water quality remains groundwater and water transfers can be of suitable quality for use. obtained by contacting DWE. The Department of Water and Energy (DWE) regulates access Using groundwater In addition, there are areas to groundwater in New South of Botany Sands to the north One of the most common uses Wales. Before you sink a bore t t of Botany Bay that have had for groundwater in commercial t you must first obtain a licence t groundwater extraction buildings is for cooling towers. or an approval for the works restrictions imposed as a Bore water generally has higher from DWE. All bores must be t t precaution because of the levels of dissolved solids than constructed by a licensed driller. likelihood that the groundwater mains drinking water and may t t may be contaminated. need to be treated before it can t The main reason for bore t Domestic use in these areas be used in cooling towers. t licensing is to ensure that this t is banned and industries are limited resource is equitably required to test their licensed Groundwater is also commonly and sustainably shared among groundwater extraction and used for irrigation. This may only t t t competing interests. It allows t demonstrate to DWE that be cost effective if your shopping

ready contact with licence t centre or commercial building holders incase significant t t resource management issues arise, such as water t shortages or contamination.

t t t There are groundwater t embargoes in place for t commercial use of groundwater around Sydney. In particular, Figure 19 – The water reuse system at Kogarah Town Square these include the Botany Sands aquifer in the Eastern Suburbs of Sydney and around Botany Useful documents Bay, as well as the Hawkesbury Managing urban stormwater harvesting and reuse 2006, Department of Environment and Climate Change sandstone aquifer in the Blue NSW outlines some regulatory issues associated with stormwater harvesting and provides advice on how to Mountains area and parts of plan a stormwater harvesting project. the Southern Highlands. These embargoes prohibit DWE from Reference accepting new water licences. Yuldeson, J, 2006, Developing Green Case Studies, National Association of Industrial and Office Properties, Figure 20 – Groundwater management zones for the Botany Aquifer, located south of Sydney. Herndon, USA.

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has extensive landscaped areas. Groundwater quality It is also important to consider Groundwater has higher levels the effect groundwater will have of dissolved solids than mains on soil quality, as it may contains drinking water. Some of the high levels of dissolved salts. common contaminants in groundwater include dissolved Groundwater can be used iron, manganese and hydrogen to flush toilets and urinals. Case study sulphate. You should investigate The University of New South University of New South Wales aquifer recharge the pH of groundwater and Wales uses groundwater consider its likelihood to in some of its amenities cause corrosion or scaling if and has trialled the use of The University of New South Wales (UNSW) uses water from the Botany Aquifer to irrigate it is not treated before use. groundwater in cooling towers. its lawns and ovals and meet other non-drinking water demands such as toilet flushing and laboratory process water. UNSW is also using stormwater captured in the lower part of its The amount of treatment Before using groundwater, campus to help recharge the aquifer. groundwater needs will depend you need to consider: on its particular properties and UNSW has built a 10 metre If the chamber fills up, 80 per cent of its current • what quantity of the sensitivity of your end uses. wide percolation chamber it overflows into local extraction. (Frew, 2007) groundwater you need under its cricket oval to stormwater drains that References collect stormwater from 70 drain to Botany Bay. Photographs 16 and 17 – The University of New South • if the groundwater can per cent of the main campus. Frew, W, 2007, What a catch: Wales aquifer recharge system deliver a sustainable yield This water is allowed to UNSW expects to return 160 the cricket oval that saves water contributes to the Botany Aquifer - seep back into the sands megalitres of stormwater to in the Sydney Morning Herald, shown during construction (above) • what treatment the of the Botany Aquifer. the aquifer, which is about and the completed system (below) 22 January 2007, John Fairfax groundwater may during a period of heavy rainfall. need to undergo Publishers, Sydney. Also available online: http://www.smh.com.au/ • other land uses in the news/national/what-a-catch-the- groundwater catchment and cricket-oval-that-saves-water/ potential for contamination 2007/01/21/1169330767465. html • what approvals you need before drilling a bore and using groundwater.

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Chapter 23 Wastewater reuse

Wastewater can be a valuable and reliable source of alternative water, however it requires proper management and treatment before it can be reused because it has been polluted with a range of contaminants.

Wastewater can be classified Using greywater • determine if these three ways: treatment processes will Greywater with low levels of remove contaminants and pathogen contamination, oils Greywater includes wastewater make water safe for users and greases can be used for from baths, showers, basins, and the environment. sub surface irrigation with little laundries and kitchens. treatment. Greywater with Greywater can be contaminated Preventing hazardous higher levels of treatment can by human faeces especially if contaminants going into a be used for above surface cloth nappies are being washed. greywater system is the best way irrigation and indoor uses such Kitchen wastewater may also of ensuring greywater quality. To as toilet flushing. be regarded as greywater, but do this you can: treatment and reuse is more Before planning to reuse complex because it may be • exclude kitchen waste greywater, you need to: alkaline and can contain large because of high levels of oil, grease and amounts of grease, fat, food • calculate how much bacterial contamination waste and detergents. greywater you generate and from food wastes how much you can reuse Black water (domestic sewage) is wastewater from toilets • identify the contaminants and bidets that is heavily and that your greywater contains directly contaminated with human wastes and contains • decide on intended uses contaminated solid material, for the greywater, i.e. such as toilet paper. Black water irrigation, toilet flushing is likely to have high levels of bacterial contamination and can • determine how much be highly infectious. contact people will have with reused greywater Sewage is a combination of black water and greywater, as well as • identify if there will trade waste from commercial be any environmental and industrial activities. risks associated with greywater reuse

• decide on the treatment processes you will use

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• exclude laundry water when Sub surface greywater Greywater treatment system blackwater or sewage. While Approval must be in accordance 4. identify the system’s items soiled with faeces or irrigation systems must these wastewater streams are with the Local Government critical control points other excrements are washed be installed at least 10 A greywater treatment more heavily contaminated Act 1993 and Regulations. because of high levels of centimetres underground to system must be used if and require more treatment, 5. understand how the system bacterial contamination reduce human exposure to greywater contains kitchen having a larger volume of In New South Wales, the of wastewater collection, any potential pathogens. wastewater, or if you want wastewater to treat might Department of Water and Energy treatment and reuse works • ensure cleaning and garden to use greywater for toilet be more cost effective. (DWE) and NSW Health can chemicals are not disposed Diversion devices are not allowed flushing, washing machines or advise local councils when they 6. develop a system of in the greywater system to store greywater because unrestricted garden irrigation. Building owners can either are processing the applications. management manual harmful pathogens can grow in use the sewage generated • choose the right household storage tanks and unpleasant A complete greywater treatment on-site, or access nearby sewer Local government approval is 7. test and validate the cleaning products. odours can develop. Any system may include components mains. Accessing wastewater not required where, under the system’s performance for greywater that is not used for such as wetlands, intermittent in nearby mains is known as Protection of the Environment 12 weeks after approval to It is very important to irrigation must be disposed of sand filters, soil filters, greywater sewer mining. Approval is Operations Act 1997, an install the system is received communicate with building to sewer. To avoid waterlogging septic tanks and aerated required from the relevant local environment protection licence 8. conduct a further four users and cleaners so that they your soil, don’t apply greywater wastewater treatment systems. council and Sydney Water. is in force for a sewerage weeks of testing after understand what they can and after rain. Diversion devices These processes remove management scheme. approval to operate the cannot put down the drain and must have a screen to remove pollutants including solids but Organisations who want to system is received when water must be diverted any large pollutants, such as will not remove harmful bacteria. sewer mine should discuss their It is strongly recommended that to sewer. plans with Sydney Water to make recycled water schemes comply lint or twigs that could clog 9. undertake continuous online Disinfection is required where sure the project is possible and with the NSW Government spray systems or pumps. monitoring and regular If you plan to use greywater there will be human contact the existing sewer infrastructure guideline for the Management of manual monitoring when for irrigation, you must ensure Greywater must be diverted with reused greywater. When can cope with the proposed Private Recycled Water Schemes. the system is operating that the volume of water will to sewer if there is a known secondary treated greywater project. If the project is feasible, and divert the system to not be more than the holding source of faecal contamination is disinfected using an active Sydney Water will provide To manage the risks of a sewer if critical control capacity of the receiving soils. in the system or an outbreak disinfection process such as initial development approval recycled water system and points are breached of infectious disease amongst chlorine, bromine, ozone or and construction approval. gain approval to install and There are two devices commonly ultra violet light, it will reduce operate, you should: users of the buildings. 10. ensure a person or available to reuse greywater: the levels of harmful bacteria Approvals and organisation has Diversion devices can be and make greywater safe 1. conduct a risk assessment plumbing regulations responsibility for Greywater diversion device operated by gravity or pump. for more human contact. on the sources of In New South Wales, local wastewater and its managing the system If you are confident that your Pump devices have a surge government approval is intended uses greywater system excludes tank that controls the amount Sewer mining and required to install and kitchen wastewater and does not of greywater sent to irrigation. black water reuse operate systems of sewage 2. ensure the treatment have heavy pathogen loads, you The surge tank should not The amount of greywater management that service system has multiple barriers can use a greywater diversion be used as a storage tank. generated onsite can sometimes more than one household. device to divert greywater 3. ensure disinfection be insufficient to meet your This requirement applies to to sub surface irrigation. is included as a demand for recycled water and greywater reuse systems. it may be more efficient to use treatment process

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11. think about additional sewer will not affect your Greywater treatment systems ways you can manage Trade Waste Agreement. and costs may be simpler recycled water in the than black water and sewage building, ie signs, Useful documents reuse projects, but as most education, coloured commercial buildings have plumbing pipes and • Australian Guidelines for more access to black water fixtures and regular Water Recycling: Managing or sewage than greywater, plumbing compliance Health and Environmental it may be more feasible to checks to detect Risks. National Resource reuse this waste stream. cross connections Management Ministerial Council (NRMMC), Environment In commercial buildings, the 12. ensure the system Protection and Heritage costs of designing systems to complies with plumbing Council (EPHC) and Australian comply with regulatory and requirements of the Health Ministers Conference health requirements, then local authority (AHMC), 2006. This document testing, maintaining and outlines how to approach Case study monitoring them may be high. Wastewater reuse in Melbourne If your wastewater reuse system a risk-based approach to will be operated in Sydney, recycled water systems. Given the costs of setting up a notify Sydney Water’s Plumbing well running wastewater reuse Two commercial office buildings in Melbourne demonstrate the possibilities of wastewater and Policy of any changes • Advisory Note 4: Sewage system, it is important that you treatment and reuse. to your plumbing. Plumbing Management Facility have an accurate idea of how requirements for recycled water Accreditation Criteria Based much greywater you will be Urban Workshop at 50 recycled water is returned down organic matter and installation are outlined in the on the Final Application of collecting and how much you Lonsdale Street and Southern to rooftop tanks for use in membrane treatment to filter most recent edition of the New Treated Effluent and Risk will be using. Cross on the corner of Bourke toilet flushing. However, the microscopic contaminants, South Wales Code of Practice: of Disease Transmission, and Exhibition Streets are water is too salty to be used and the tertiary treatment Plumbing and Drainage. NSW Health, 2006. It is advisable to conduct an both occupied by Victorian in cooling towers without disinfects using ultraviolet audit or an irrigation assessment Government staff. Combined, additional treatment. radiation and chlorine. Sydney Water will review your • Management of Private before designing your system. the two buildings save system to make sure there are Decentralised Recycled Reuse projects will be most 47 megalitres of drinking Both buildings use a three Similar systems will be no potential health threats, such Water Systems (draft), NSW successful when all stakeholders water a year by treating stage process to treat their installed in three more as cross-connections between Department of Energy, are committed to operating a and reusing about 75 per wastewater. The primary multi-story office buildings in your drinking water supply Utilities and Sustainability. viable system that produces cent of their sewage and treatment screens solids, Melbourne in coming years. and your greywater system. good quality water. greywater. After treatment, the secondary treatment (City West Water, 2007). uses microbes to break Costs and advantages You should also talk to your Sydney Water trade waste Wastewater can provide a Photograph 18 – Southern Cross on the corner of Bourke and Russell Streets (left) and the Urban Workshop at 50 representative to make sure regular source of alternative Lonsdale Street (right) are two Melbourne buildings that demonstrate how wastewater can be treated and reused at a commercial location. that changes to the quantity water and well run systems can or quality of wastewater significantly reduce demand you intend to dispose of to on drinking water supplies.

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References Turning waste into a resource, Liquid Assets, Issue 2, 2007 City West Water, Sunshine, Victoria.

Australian Guidelines for Water Recycling: Managing Health and Environmental Risks (Phase 1) 2006 National Resource Management Ministerial Council (NRMMC), Environment Protection and Heritage Council (EPHC) and Australian Health Ministers Conference (AHMC).

Sewage Management Facility Accreditation Criteria Based on the Final Application of Treated Effluent and Risk of Disease Transmission, NSW Health, Advisory Note 4 – May 2006, http://www.health.nsw.gov. au/public-health/ehb/general/ wastewater/adnote4.pdf.

119 120 Part 4 Water saving checklist

Part 4 of Best practice guidelines for water conservation in commercial office buildings and shopping centres provides a practical Water Saving Checklist that shows you how well you manage water. The checklist will help you work your way through these guidelines and identify opportunities for water conservation in your commercial building or shopping centre.

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Water saving checklist

Managing your water Answer Yes / No Recommended action Amenities Yes / No Recommended action

Do you monitor and record your If No, read your meter at least daily, or install a continuous Have you installed sub metes on If No, install meters on supply lines to amenities, as described Yes No Yes No water use? monitoring system. Record meter reading information so supply lines to amenities and hot in Chapter 9. Conduct routine inspections and program you can identify changes in water use. water supply? maintenance to detect problems before they become

large leaks. 2 Do you benchmark your Yes No If No, calculate a L/m /annum figure and compare it against Does your building have any cyclic If Yes, replace urinals immediately with manually flushing water consumption? other buildings in your portfolio and the benchmarks in Yes No Chapters 3 and 4. flushing urinals? urinals, automatic sensor units or ultra low flow or waterless urinals. Refer to Chapter 13. Do you know where water is used Yes No If No, look at the average water balance graphs in Chapters Does your building have If Yes, regularly check that sensors are working properly and in your office building or 3 and 4 for guidance. Install sub meters according to the Yes No shopping centre? priorities in Chapter 9 to develop your own water balance. automatic on-demand urinal not detecting unrelated movement. Check that solenoids are sensor flushing systems? operating correctly and replace them if they are faulty Do you know where the best If No: Yes No or worn. opportunities to save water are? - check for leaks Does your building have single If Yes, replace single flush toilets in high use areas - check cooling tower operations Yes No flush toilets? with 6/3 litre or 4.5/3 litre dual flush models. If - install flow restrictors on taps toilets are in low use areas, restrict cistern volume - remove all cyclical flush urinals and bring forward programmed replacement. - develop a water balance for your building and see where Does your building have dual- If Yes, check the flush capacity. Older 11/5.5 litre and 9/4.5 litre you are using most water Yes No flush toilets? dual flush toilets can be replaced with new 6/3 litre or 4.5/3 Do you regularly review your If No, use the One-2-Five® Water or Water Achiever process litre flush models. Yes No company’s water management? offered through the EDC Business Program and concentrate Are cistern rubber seals on toilets If No, cistern rubber seals should on achieving identified critical actions. Yes No replaced regularly? be replaced every two years to prevent leaks. Use the template provided in the NSW Water Saving Action Plan guidelines. Do you have a flusherette system? If Yes, check the flow rate and flush timing. Over time, wear Yes No Compare your results to previous reviews and rate your will cause excessive flush volumes. Insert flow control achievement of critical actions. regulators into valve bodies to reduce flow. Do you have flow regulators in all If No, install flow regulators so that flow is reduced to at Do you review your sub meters, or Yes No If No, establish work procedures so that a member of staff is Yes No hand basins? least 6 litres per minute. information from your continuous responsible for water use information and knows what they monitoring system regularly? need to do to if water use changes. Do you have water If No, install flow regulators so that flow is reduced to Yes No Do you know how much water, If No, refer to information about the true cost of water in efficient showers? at least 9 litres per minute or install WELS 3 star rated Yes No and all associated charges Chapter 6. Calculate your own water costs and associated showerheads. (energy, pumping, chemical, charges, as knowing how much your water costs will sewer discharge) are costing establish a business case for water conservation. your business? Have you developed a water If No, look at the findings of this checklist then develop a Yes No savings plan? water balance and a basic savings plan.

Do you have signs, posters and If No, business partners in the EDC Business Program can Yes No stickers in your building to co-brand stickers, posters and shower hangers. encourage water conservation and remind people to report leaks? Continued overleaf

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Cooling tower operations Yes / No Recommended action Cooling tower operations Yes / No Recommended action

Does your building have If Yes, continue with this section. If No, go to the next section. Does your water treatment If No, make this part of their ongoing duties. Ensure it is Yes No Yes No cooling towers? contractor clean the conductivity recalibrated every month. sensor every month? Is there a water meter on If No, install a sub meter and monitor the water Yes No the make up water pipe? consumption regularly. Is the water treatment system If No, install a bleed blockout to ensure that unnecessary When the pump is stopped, If Yes, check that the drain valve is correctly set and if Yes No Yes No installed with a bleed blockout? bleed does not occur during chemical dosing. is there water flowing from there are any leaks. Check if the valve is closed and the overflow drain pipe? adequately sealed. Does the cooling water system If Yes, consider capturing the bleed off in a backwash holding Yes No When the pump is stopped, If Yes, this indicates that the ball float valve is incorrectly set. have a side stream filter that uses tank and then using it to backwash the side stream filter. Yes No does the water flow out of the The ball float valve needs to be reset. water for back flushing purposes? overflow drain pipe whilst the Have you contacted your If No, ask your contractor to do so. Water supply in Yes No water is coming in through water treatment contractor to Sydney should be able to be cycled to about 9. If your the make up water line? discuss increasing the cycles of contractor is unable to do this, discuss opportunities If you have a V shaped basin, If Yes, consider installing a break tank, or a more precise make concentration in your cooling of changing to a treatment system that can function Yes No when the pump stops does up control. tower to reduce the bleed rate? effectively at high cycles of concentrations. the cooling tower overflow? Does your cooling tower water Yes No If No, amend contract to ensure this occurs. If there is a significant length If Yes, consider reconfiguring the pipework. Yes No treatment contract require the of condenser water pipe contractor to report back on all work running at high level, water leaks after each service? causing the tower overflow Do you have a certificate If No, make sure your contractor can supply one. These when the pump stops? Yes No stating that an effective certificates are mandatory in New South Wales. If you have two or more cooling If Yes, check the ball float valve settings and the height of Yes No process of disinfection is towers interconnected, when the tower basin. If one basin is higher than the other some installed and operating? the pump stops does water modifications may be required. flow from the drain pipe? Is the water overflowing the If Yes, check that the overflow pipe is set correctly or Yes No edge of the tower basin? not blocked. Is the area around the tower If Yes, water is splashing out of the tower. Install or replace Yes No regularly or constantly wet? anti splash louvres. Is any leakage present in If Yes, joints need to be adjusted and sealed. Yes No the tower, casing, basin, or any intake or exhaust ducts or flexible connectors? Does the cooling tower have If No, install a drift eliminator that limits drift loss to no more Yes No drift eliminators, or old or than 0.002 per cent. ineffective eliminators? Do any pumps have packed If Yes, ensure pumps are inspected monthly and seals Yes No gland pump seals? tightened as needed. Also consider replacing the seals with mechanical seals.

Continued overleaf

125 126 4 Water saving checklist Water saving checklist 4

Cooling systems and Kitchens and food courts Yes/No Recommended action Yes / No Recommended action building design Do staff in food courts and If No, ensure all staff receive information about water Yes No Have you integrated economy If No, investigate if this can be done with your current kitchens operate dishwashers efficient dishwasher information. If you are accepting new Yes No cycle or fresh air venting into HVAC equipment. and glass washers efficiently? tenancies, make installation of water efficient dishwashers your air conditioning system? and glass washers a lease condition. Have you reduced the heat load in If No, install energy efficient lighting, building insulation, Do staff in food courts and If Yes, install water efficient 6 litres per minute WELS rated Yes No Yes No your building as far as possible? external shading, high performance insulation, sympathetic kitchens rinse plates pre-rinse spray valves. Sydney Water is offering a rebate landscaping, and heat efficient natural lighting. before washing? system for their installation. Is your cooling load If Yes, you should investigate the possibility of air cooled Do you check the condition of pre Yes No If No, inspect pre rinse spray valves every two weeks to check Yes No under 500 kWR? systems. In smaller systems, air cooled systems can be rinse spray valves? for leaks and worn valves. Worn valves waste water and appropriate because they do not consume water and have reduce cleaning efficiency. lower maintenance costs. Do staff in food courts and If Yes, install signs to remind staff to turn taps off. Consider Yes No kitchens leave taps running while installing sensor taps or foot operated taps. Waterless woks Have you looked at Lake water, groundwater, sea water, reclaimed water, Yes No they are cooking and cleaning? have hip controls and automatic turn off swivel taps. alternative water sources recycled water, rainwater and condensate may all be used in Are kitchen floors and food court If Yes, consider using mops or squeegees instead of hoses. for your cooling system? cooling systems. Yes No areas hosed down? Microfibre mops are highly water efficient. If hoses must be Have you considered other If No, investigate options including evaporative pre-cooled Yes No used, ensure they are fitted with trigger nozzles. cooling systems? air cooled condensers with pad or spray cooling, variable Is food ever defrosted under If Yes, ensure all food is defrosted in a refrigerator, or in a refrigerant volume systems, hybrid coolers or condensers, Yes No phase change materials or chilled beam technology. These running water? microwave if it is to be cooked immediately. are viable alternatives to traditionally cooling towers and Are water cooled steamers used? If Yes, install more efficient steamer equipment. Efficient Yes No should be investigated when building or renovating. steamers can use up to 90 per cent less water and up to 60 per cent less energy than older models and have shorter cook Kitchens and food courts Yes / No Recommended action times, higher production rates and reduced heat losses. Are the water supply lines Yes No If No, install sub meters on the supply lines to food Do tenants pay for their own If No, you may be able to establish leases so that sub Yes No to kitchens sub metered? businesses, especially high volume, water intensive kitchens. water consumption? metering information can be used to charge tenants for Do you benchmark water If No, use sub metering information to establish their water consumption. This gives each tenant a financial Yes No use in each of the kitchens benchmarks so you can track kitchen water use incentive for water conservation. or your food court? over time. Common benchmarks are litres per cover, Fitness centres Yes / No Recommended action litres per meal served, or litres per patron. Does your building contain a If Yes, continue with this section. If No, go to the next section Do you have flow regulators If No, install 9 or 12 litres per minute flow Yes No Yes No fitness centre? of this checklist. on kitchen sinks and basins? restrictors on kitchen sinks and 6 litres per minute restrictors on hand basins. Are the showers water efficient? If No, install 9 litres per minute flow restrictors or WELS 3 star Yes No rated showerheads on showers. Do you have waterless If No, consider installing a waterless wok. You may be Yes No woks in your kitchen? able to get information and financial assistance from Do you have flow regulators in all If No, install flow regulators so that flow is reduced to 6 litres Yes No the Ethnic Communities Council of NSW. If you are hand basins? per minute or less. accepting new tenancies into your food court, make Does the fitness centre contain a Ensure you sub meter supply and refer to the Sydney Water the installation of waterless woks a lease condition. Yes No swimming pool? fact sheet Swimming pools for benchmarking and water Do you have a water If No, replace your existing model with a Yes No conservation information. efficient dishwasher? water efficient model. You will save money through water and energy savings. Continued overleaf

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Appendix

Sydney Water benchmarks explained Outdoor areas and water features Yes / No Recommended action Do you have a landscaped area or If Yes, continue with this section. Yes No water features? Office building benchmarks Do you sub meter your irrigation If No, consider installing sub meters to determine your water Yes No The water use efficiency benchmarks presented in Chapter 3 of supply and water features? use and identify leaks. This is especially important if you have these guidelines were developed with information gathered from 31 large areas of irrigated areas or large water features. water efficiency audits conducted by the EDC Business Program. The Do you improve your soils? Improving soil quality can improve plant growth and water Yes No buildings used in the sample were large and fitted with cooling towers. retention. Add organic matter such as compost or composted animal manure. Do you use an alternative water If No, consider using rainwater, stormwater or treated Benchmark Offices with cooling towers Yes No source to irrigate your garden? wastewater for irrigation. Average practice and no leaks 1.01 kL/m2/year Cleaning Yes / No Recommended action Do you communicate with If No, cleaning staff will need information about water wise Yes No Economic best practice (median of cleaning staff regularly? cleaning techniques and the correct way to clean specialized implementing water saving projects with 0.84 kL/m2/year equipment such as waterless urinals. You can use Sydney two year paybacks) Water EDC Business Program stickers, poster and fact sheets to communicate with staff. Very well managed building 0.77 kL/m2/year Do cleaners hose down floors If Yes, remember that water restrictions prohibit the hosing Yes No or carparks? of hard surfaces. Use brooms or mops to clean floors, or use rainwater or other water sources if you must use the hose. In Office building benchmarks – without cooling towers most large carparks, commercial street / foothpath cleaning equipment can be used. Benchmarks for buildings without cooling towers were developed by taking out the proportion of water use attributed to cooling towers. These adjusted benchmarks have not been verified against the population and should be interpreted as an indicative estimate.

Offices without Benchmark cooling towers

Average practice and no leaks 0.64 kL/m2/year

Economic best practice (median of implementing water saving projects with 0.47 kL/m2/year two year paybacks)

Very well managed building 0.40 kL/m2/year

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Glossary

Office building benchmarks – with small retail areas ABGR The Australian Building Greenhouse Rating System. Benchmarks were also derived for office buildings that supply water Backflow The unwanted reverse flow of water in the potable to one or more retail tenants in the building. These benchmarks can water system. be used if you are unable to separate the water consumed by retail tenancies within your office building. BASIX BASIX is a regulatory tool applied to new houses, home renovations and multi-unit dwellings in NSW Offices with small retail Benchmark Bleed The water that is removed from a cooling tower areas on common meters to reduce the concentration of dissolved and Average practice and no leaks 1.08 kL/m2/year suspended solids.

Economic best practice (median of Cooling load The amount of heat which needs to be removed to 0.90 kL/m2/year implementing two year paybacks) keep an occupied building at a set temperature and the energy required to do this. Very well managed building 0.82 kL/m2/year Cycles of The number of times the concentration of dissolved concentration and suspended solids in cooling tower water is These adjusted benchmarks account for the additional water increased because of evaporation. Four cycles of consumption used by retail activities within your building. They are concentration means the concentration of solids derived based on the average impact of retail on office buildings has been increased by four. within the sample sets – typically up to one level of retail in a multi level office tower. Drift Water lost from a cooling tower as liquid droplets within the exhaust air. Drift does not The benchmarks should be interpreted in this context and may not be include condensation. appropriate for large retail or food court installations. If you have large retail or food court areas in your building, install more sub meters to GLA Gross Lettable Area is the floor space of a tenancy make sure you can keep track of water use. in a shopping centre.

HVAC Heating, ventilation and air conditioning.

Greenstar Greenstar is a building environmental rating system for buildings run by the Green Building Council of Australia.

LEED LEED is a USA standard for the design, construction and operation of high performance green buildings.

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Legionella Bacteria that can cause a type of pneumonia is Thermal Mass The amount of time building materials take to gain called Legionnaires Disease. Legionella bacteria can or release heat. A building with a high thermal multiply rapidly in wet, warm conditions. mass will be more energy efficient because internal temperatures will not swing with outside NABERS The National Australian Building Rating System, a air temperatures. voluntary building performance rating tool. WELS Water Efficient Labelling Scheme. As part of the NLA Net Lettable Area, the floor space of a tenancy in a Water Efficient Labelling and Standards program, commercial office building. WELS gives products a star rating according to their water efficiency. An overview of water consumption One-2-Five® A management diagnostic process that analyses required for WELS ratings is shown in Chapter 13 of Water qualitative or non technical measures that all these guidelines. businesses must address to achieve sound water management. One-2-Five® is a patented process of WaterMark™ WaterMark™ certification shows that water supply, Energetics Pty Ltd. sewerage, plumbing and drainage goods meet quality standards. Phase change Materials that can store and release heat. Active materials phase change materials can change state, for Wet bulb The lowest temperature that can be obtained example ice has a capacity to cool warmer, ambient temperature by evaporating water into the air at constant air and absorb heat by melting. pressure. Wet bulb temperature will be lower than dry bulb temperature in the same conditions. Pre rinse A handheld nozzle used to remove food scraps from spray valve dishes before they washed.

Solenoid An electro mechanical device that activates a valve.

Splash In cooling towers, the water that can be lost because of falling water in the tower, or strong winds blowing through the tower.

SUDF Sewerage Usage Discharge Factor is a measure of the ratio of water going out of your business through the sewerage system compared to water coming in from Sydney Water mains.

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Index of illustrations

Part 1 Understanding your water use

Reference Description Page Table 7 Elements and critical actions identified for initial 36 One-2-Five® Water management diagnostics Figure 1 Water used by commercial buildings, Sydney 2006 8 Table 8 Elements and critical actions identified in review 36 Figure 2 Trends in lettable office space 9 One-2-Five® Water management diagnostics

Figure 3 Trends in office space vacancies 9 Photograph 3 Citigroup Centre 38

Figure 4 Total number of shopping centres (by type) 10 Figure 12 NSW Department of Commerce online 42 Figure 5 Breakdown of total GLA by shopping centre type 10 monitoring system

Table 1 Classification of shopping centres 10 Figure 13 Developing a water balance 44

Table 2 Benchmarks for water efficiency in office buildings 12 Figure 14 Water efficiency audit process 49

Figure 6 Typical water distribution in a commercial building 13 Photograph 4 Mandarin Centre 53

Table 3 Comparison of Sydney Water performance 15 benchmarks and NABERS

Photograph 1 Stocklands House facade 16 Part 2 Technical water saving information

Table 4 Benchmarks for water efficiency in 18 Reference Description Page shopping centres Photograph 5 Ian Bentley, Jones Lang LaSalle 63 Figure 7 Typical water distribution in a shopping centre 19 Table 9 WELS rating specifications for tap ware 65 Table 5 ABGR Star ratings 22 Table 10 WELS rating specifications for toilets 65 Photograph 2 Lake Burragorang 25 Table 11 WELS rating specifications for showers 65 Figure 8 EDC Business Program ‘Cost of water’ pyramid 26 Table 12 WELS rating specifications for urinals 65 Table 6 Review of common operating and capital costs 27 Figure 15 Key features of a typical cooling tower 68 Figure 9 Sydney Water’s water use charges 29 Figure 16 CH2 cooling and ventilation system 70 Figure 10 EDC Business Program process for customers 33 Table 13 Low heat load producing alternatives to 74 Figure 11 Water consumption in Macquarie Real Estate 35 conventional lighting Capital commercial Sydney buildings Photograph 6 30 The Bond facade 76

Table 14 Common sources of heat found in shopping centres 78

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Every Drop Counts Business Program

Part 2 Technical water saving information (continued) Sydney Water’s Every Drop Counts (EDC) Program helps Reference Description Page large water using businesses, including commercial Table 15 Water and cost savings with low flow pre rinse 83 property owners and managers, save water by better spray valves management and cost effective technical measures. Photograph 7 Waterless wok 84 Small to medium water using businesses can also use Photograph 8 Rouse Hill Town Centre 88 information provided by the EDC Business Program, such as fact sheets, best practice guidelines and marketing materials. Photograph 9 CH2 roof garden 89

Photograph 10 Archibald fountain 90 Contact us

Photograph 11 Water reuse during fire service testing 92 For more information about the EDC Business Program, contact:

Figure 17 Sydney Water’s ‘Don’t use fire hoses’ sticker 93 Email [email protected] Phone 1800 661 161 Fax 02 9350 5942 Part 3 Alternative water sources Website www.sydneywater.com.au Reference Description Page

Photograph 12 Rainwater use at 73 Miller St 98

Photograph 13 Rainwater capture at Macarthur Square 102 Photograph 14 Blackmores head office 103 Figure 18 Differences: rainwater, stormwater, greywater and 104 black water Photograph 15 Kogarah Town Square water feature 108 Figure 19 Kogarah Town Square water reuse system 109 Figure 20 Botany Aquifer 110 Photograph 16 UNSW Aquifer recharge system 112 Photograph 17 UNSW Aquifer recharge system 112 Photograph 18 Southern Cross and the Urban Workshop 118

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