BLACKTOWN STORMWATER HARVESTING & REUSE SCHEME FINAL REPORT May 2015 Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 1 Contents 1. EXECUTIVE SUMMARY ................................................................................................................ 4 2. PROJECT OVERVIEW.................................................................................................................... 6 3. 4. 5. 2.1. Location ............................................................................................................................... 6 2.2. History and Context ............................................................................................................ 6 2.3. How the Scheme Works ...................................................................................................... 7 2.4. Project status .................................................................................................................... 17 PROCESS AND METHODS .......................................................................................................... 18 3.1. Project governance ........................................................................................................... 18 3.2. Project activities and conduct ........................................................................................... 18 3.3. Water quality management .............................................................................................. 19 3.4. Stakeholder and Community Consultation ....................................................................... 20 PROJECT ASSESSMENT .............................................................................................................. 21 4.1. Objectives and key performance indicators ..................................................................... 21 4.2. Project finance .................................................................................................................. 22 4.3. Potable water savings achieved by the project ................................................................ 24 4.4. Levelised cost of water supplied as a result of the project .............................................. 24 4.5. Amount of GHG emission offset ....................................................................................... 25 4.6. Other environmental benefits .......................................................................................... 26 EXPERIENCE SHARING AND LESSONS LEARNT .......................................................................... 27 5.1. Project results and outcome realisation ........................................................................... 27 5.2. Major project issues .......................................................................................................... 27 6. PROJECT FUTURE ...................................................................................................................... 29 7. CONCLUSIONS ........................................................................................................................... 30 ATTACHMENTS.................................................................................................................................. 31 Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 2 Report Sign Off Function Author/Project Manager Position Catchment Projects Officer Name Craig Bush Approved by Director Design and development Glenys James Approved by General Manager, Blacktown City Council Kerry Robinson Signature Blacktown Stormwater Harvesting and Reuse scheme – Final Report Date Page 3 1. EXECUTIVE SUMMARY The Blacktown International Sportspark (the Sportspark) is a high profile regional sporting complex located in Rooty Hill, approximately 35km west of Sydney, NSW. The Sportspark is used by Cricket NSW, AFL NSW/ACT, Western Sydney Wanderers, Softball NSW, Athletics NSW and many more. As the facilities are required to be at a high standard Blacktown City Council, with assistance from the Australian Government, has built the Blacktown Stormwater Harvesting and Reuse Scheme (the scheme) to supply an alternative supply of water to this facility and surrounding reserves. The scheme is capable of collecting and cleaning 200 million litres of stormwater per year, which is equivalent to approximately 80 Olympic sized swimming pools. The water will be used to irrigate the Sportspark, Anne Aquilina Reserve, Kareela Reserve and Charlie Bali Reserve, as well as topping up the Nurringingy Reserve ornamental lakes. See figure 1 for location of the scheme in relation to Sydney. The scheme was originally designed as a Managed Aquifer Recharge scheme where the collected stormwater was to be pumped into an aquifer and stored in the aquifer until it was extracted for irrigation. Intensive drilling investigations discovered that the aquifer was too deep and the flow rates were insufficient to support such a large scheme therefore the managed aquifer recharge scheme was abandoned. The stormwater harvesting scheme was then modified to store the stormwater in above ground storages such as ponds and wetlands. Figure 1 – Location of Blacktown Stormwater Harvesting and Reuse Scheme in relation to Sydney The scheme has the following benefits for Blacktown City Council, including: - Reducing potable water used for irrigation and toilet flushing Increasing the drought resistance of the sporting fields during drought periods Improving the quantity of water being supplied to the Sportspark Improving the condition of Angus Creek. Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 4 The Australian Government, through the National Urban Water and Desalination Plan, contributed $2,212,500 to the project. The NSW government also contributed $286,000 to the scheme via the Waste and Sustainability improvement Program. Blacktown City Council, through the Environmental Stormwater Management Program, contributed $3,737,860 to the project and therefore the total project budget was $6,236,360. As of May 2015 the Scheme is fully constructed and commissioned but is undergoing extensive water quality monitoring to ensure the water being supplied by the scheme is fit for purpose for irrigation and toilet flushing. Council intends to have the scheme fully operational before October 2015 to make the most of the upcoming summer when irrigation demand will be at its highest. Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 5 2. PROJECT OVERVIEW 2.1. Location The Blacktown Stormwater Harvesting and Reuse Scheme (the scheme) collects stormwater from Angus Creek, which has a 655ha catchment that drains the suburbs of Rooty Hill and Minchinbury. The catchment consists of low and medium density housing with small areas of commercial development. Approximately 35% of the catchment is classified as impervious (hard surfaces such as roads, paths, roofs etc.). The Angus Creek catchment generates approximately 2 billion litres of stormwater in an average rainfall year and the scheme has approval to harvest 200 million litres per year, which is equivalent to 10% of the average total flow. The Stormwater is collected, treated and distributed in the Blacktown International Sportspark, Rooty Hill within the Chifley electorate. 2.2. History and Context In 2007/8 the Australian Football League (AFL) and Cricket ovals were constructed in the Blacktown International Sportspark (the Sportspark). As part of this project Council installed a water quality treatment system to treat recycled water that was to be delivered by Sydney Water as part of the recycled water pipeline (purple pipe), similar to the infrastructure in Rouse Hill. Shortly after the fields were constructed Sydney Water decided not to install the recycled water pipeline to the area. This meant that Council had the infrastructure to support recycled water but no supply. To compound this Sydney Water also did not upgrade the potable water supply at the time of construction of the sporting fields as the recycled water pipeline was going to be used for irrigation, which is the biggest usage of water. Therefore the sportspark not only didn’t receive the recycled water pipeline they also didn’t receive the upgrade in the potable water supply line which meant that there was a considerable shortfall of water being supplied to the Sportspark (a rate of less than 5 litres a second). The managers of the Sportspark (Blacktown Venue Management) were then forced to ration their water during dry and hot periods as the water supply was not substantial enough to irrigate all fields. This meant that only the high profile fields received water and the “back fields” were allowed to degrade. In response Council started to investigate ways that the Sportspark and the surrounding fields can be irrigated using an alternative supply of water such as stormwater harvesting and reuse. The first potential solution was a managed aquifer recharge scheme. This scheme would pump stormwater from Angus Creek into an aquifer and then extract this water when it was required for irrigation. Blacktown City Council undertook extensive investigative drilling to determine if the aquifer underneath the Sportspark was suitable for such a scheme. The drilling results clearly indicated that this type of scheme would not be suitable in the area as the depth and size of the aquifer were inadequate for the size of the scheme. Further investigation into an alternative scheme was required. The preferred approach is to use an above ground stormwater harvesting system. Council will harvest the stormwater from Angus Creek but instead of storing the water in the aquifer is stored in a series of ponds in the Sportspark before final treatment and distribution. The following section will explain how the scheme works in more detail. Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 6 2.3. How the Scheme Works 2.3.1. Off-take Point As part of the Scheme Blacktown City Council carried out bank stabilization in the creek (photo 1) and built a large rock lined dam on the eastern bank of Angus Creek between the M7 overpass and the western railway line to Penrith. This dam is capable of storing 1 ML of stormwater. Photo 1: Angus Creek Photo 2: The Offtake dam (half capacity) The flow of stormwater in the creek is diverted into the offtake dam via a flow control structure and a tilting weir system. The flow control structure, which is concrete structure that is built across the creek, allows Council to calculate the stormwater flows by measuring the height of the water as is passes through a notch in the concrete structure. The tilting weir has pollution deflector veins (similar to a Baramy Gross Pollution Trap) that prevent floating pollutants from entering the pool. Behind the deflector is a steal tilting weir that can be adjusted to allow flows above 10 litres per second into the pool. This ensures that Council will only be harvesting stormwater during rainfall events and that environmental flows are not taken. The weir can also be used to prevent any flows into the offtake pool in case there is chemical spill or similar in the catchment. Council has also installed a flow monitor in the creek that will turn the Offtake Pool pumps on when flow in the creek is measured above 10 litres per second. This is a secondary measure to ensure there is ample flow in the creek when harvesting is to occur. Photo 3: The flow control structure Photo 4: The tilting weir with pollution deflector The way in which water enters the offtake pool is shown in Figure 2 below. Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 7 2 3 5 6 1 4 7 Key: 12345- Angus Creek bed control structure tilting weir structure offtake dam steel cage inlet to pump station 6- pump station 7- maintenance access point blue arrow = flow of stormwater large blue arrow = high flows Figure 2: Aerial view of the Offtake Pool structure and an indication of how it works. During heavy rainfall events when the flow in the creek reaches above the wall dividing the creek and the offtake pool the water will flow into the offtake dam directly over the wall. Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 8 Once the stormwater is collected from the creek it will pass through a steal mesh cage (marked 5 in figure 2) excluding any debris such as litter, branches, and leaves. Once the water has passed through the cage it is pumped to the harvest storage ponds. The pumps in the offtake pump station can pump up to 40 Litres per second and use a variable speed drive. The pump station also has a turbidity and electric conductivity meter that measures the quality of the water being harvested. If the water quality fails to meet the correct standard the pumps are switched off until the water settles out. This prevents the system from harvesting unsatisfactory water. 2.3.2. Harvest Storage Ponds The three harvest storage ponds are located in the center of the Sportspark and serve a dual purpose. The ponds were originally built as a flood mitigation measure that receives runoff from the roads, car parks, open spaces, and sporting fields via swales and piped systems. To increase the storage potential the ponds were deepened from 5ML to approximately 8ML. Works were also required to hydraulically connect the ponds so that the water levels rise and fall at the same rate. The water from the Offtake dam is pumped into pond 1 and the water is extracted from pond 3. Separating the inlet and outlet gives the contaminants in the water an opportunity to settle out. To provide additional treatment Council has install over 400 square meters of floating wetlands and riparian vegetation on the outer edge of the ponds. The floating wetlands act as a filter, their roots dangle in the water removing soluble nutrients and using it for plant growth. These floating wetlands will also prevent any algal growth that is known to occur in the ponds during hot summers. The floating wetlands and bank vegetation also provide habitat for local birds, frogs, and other wildlife. Photo 5: Pond 3 with outlet cage Photo 6: Pond 2 with floating wetlands Photo 7: Floating wetland raft structure Photo 8: Root structure of floating wetland (photo from Sean Harris) Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 9 P3 Floating wetland rafts Key: Blue lines = stormwater harvesting flow Yellow lines = swale or piped flow Orange lines = flood flows Green lines = hydraulic connection between ponds P2 P1 Figure 3: Aerial view of the Harvest Storage Ponds The water is pumped from harvest storage pond 3 using a 12 litre per second pump. Before the water is pumped it has to pass through a steal mess cage similar to the Angus Creek offtake dam pump station. This cage is to prevent debris greater than 5mm from entering the pumping station and being pumped into the treatment wetland. 2.3.3. Treatment Wetlands The treatment wetland is approximately 3,300m² in size and was planted out with over 50,000 aquatic/wetland plants. The dense planting in the treatment wetland absorbs excess nutrients, and removes heavy metals and hydrocarbons from the system. This treatment wetland has been designed to act as a polishing system for the water and to reduce the amount of mechanical treatment required at later stages. Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 10 The treatment wetland features a series of level spreaders and baffles to ensure that the flow of water into the wetland is evenly distributed, and to minimize the chances of directional flow paths. The baffles force the water to take a particular path and lengthen the time taken for the water to travel from the inlet to the outlet improving water quality. There is also a level control device that allows Council to control the height of the water in the wetland and to drain the wetland, if maintenance is required. One issue during the establishment phase was the predation of the plants by the large water bird population in the area. The birds, in particular swamp hens, damaged and removed plants which increased the establishment time. This issue was managed by increasing the water level making it harder for the water birds to reach the bottom of the wetland and remove the plants. Photo 9: The treatment wetland Photo 10: The wetland inlet, pool and level spreader The outlet structure to the wetland is a pit with a shroud that surrounds the inlet. This is different to the other outlets as the shroud protects the inlet from floating debris and any hydrocarbons from entering the pit as the water can only access the pit a few centimeters below the surface. Compared to the cage systems that only prevents debris. Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 11 2 1 4 3 5 Key: 123456- Inlet pipe and pool Level spreader Deep pool section Level control device Baffle system Outlet pit and pump station Blue arrow = flow Yellow arrow = inflow from sporting field runoff 6 Figure 4: Aerial view of the treatment wetland The water is pumped from the wetland pump station using a 12 litre per second pump into the AFL pump shed where it will receive mechanical treatment, as described below. 2.3.4. Treatment and Storage Tanks Council requires the water produced by the scheme to be fit for purpose, including no access restrictions for irrigation and toilet flushing, which is considered a level 1 treatment when referring to the Australian Guidelines for Water Recycling. The water quality produced by the scheme will therefore need to be low in turbidity and E.coli levels. The ponds, floating wetland and treatment wetland will remove the majority of sediment (turbidity) and bacteria (E.coli) from the water before the mechanical treatment process. To ensure that the water quality is fit for purpose Council has installed the following filters and disinfection methods to further polish the water. Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 12 2.3.4.1. FIRST PHASE TREATMENT 2.3.4.1.1. Chlorination System A Sodium Hypochlorite (liquid chlorine) dosing system will add chlorine to the water removing a large variety of disease causing pathogens, such as bacteria, viruses, and protozoans. This system has the following features: o o o o This chlorination system has a 1000L tank that is installed in its own storage shed to reduce impacts of heat and direct sunlight that reduces the concentration of chorine Council predicts that this tank will need to be filled approximately 5 times a year if the full 200ML is treated The chlorine bonds to any organic matter in the water which will make it easier for the particle filter to remove the organic matter later in the treatment train The dosing system should leave a chlorine residual level of 1 mg/L. Particle Filter 1 Particle Filter 1 is a screen filter that has a 200 micron screen. This filter will remove particles greater than 200 microns that carry pathogens, nutrients and heavy metals. This filter has an automatic backwash system that self-cleans the filter when there is a buildup of particles that reduce the performance of the filter. The backwash is directed into the sewer. Figure 5 below provides an indication of how the water treatment system works. 3 4 6 1 2 5 Figure 5: The first phase treatment system. Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 13 The first phase treatment system is located between the wetland pump and the AFL tanks. The blue line/arrow indicates the direction of flow in the system and the orange arrow indicates water after final treatment being delivered to the storage tanks (read next section for more information). Below is a description of the components numbered: 12345- The chorine dosing system A water meter that records the total volume of water harvested Particle filter 1 A water quality monitoring point A gauge that sends information back to the chlorine dosing system that indicates the level of residual chlorine – the system automatically increases or decreases dosage to achieve the desired level of residual chlorine. 6- A bypass pipe section that misses the filter (mainly used for commission to determine if filter is working – i.e. a water sample using the filter and not using the filter). After the particle filter the water is stored in a series of tanks in the AFL precinct. These tanks can store 800KL of water and are the supply point where the Sydney Water potable supply enters the system if there is no water being supplied from the stormwater harvesting system. Therefore there are two sets of float switches that trigger the system to either start supply or stop supply within these tanks, for both the potable water and the harvested stormwater. 2.3.4.2. SECOND TREATMENT PHASE When there is a demand for water, either from irrigation of the AFL grounds or to fill a tank at one of the reserves, the water is gravity feed back into the pump shed. The water is pumped through the system using a series of pumps. Each pump has a flow rate of up to 11 litres a second and uses variable speed drives. These pumps maintain pressure within the distribution line and irrigation line. Before the water is pumped out of the AFL shed it is treated via the following. 2.3.4.2.1. Particle Filter 2 Particle filter 2 is another screen filter that removes all particles greater than 100 micron. This filter is important as any particles greater than 100 micron can block the sprinkler heads and the smaller the particle size the more effective the UV filter will perform. This filter has an automatic backwash system that self-cleans the filter when there is a buildup of particles that reduce the performance of the filter. The backwash is directed into the sewer. 2.3.4.2.2. Ultraviolet (UV) disinfection unit A UV disinfection unit is used to remove any pathogens that have survived the chlorination system. o o o UV disinfection units remove pathogens in the water as the UV energy penetrates the outer cell membrane, passes through the cell body and disrupts its DNA preventing reproduction. One of the key benefits to UV disinfection units is that UV treatment does not alter water chemically and that there is nothing added to the water and you only need electricity to run the unit. Therefore there is minimal maintenance required. One key factor that impacts the performance of UV disinfection is the turbidity level of water. A turbidity level of greater than 5 NTU will reduce the effectiveness of the UV radiation from hitting the pathogen as it could be shielded by the particles there not being treated. Hence Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 14 why it is so important to have a filter that removes particles before the water reaches the UV disinfection unit. 2 4 1 3 5 Figure 6: The second phase treatment system. The treatment system after the AFL tanks before irrigation and distribution. The blue line/arrow indicates the direction of flow in the system. Below is a description of the components numbered: 1- The water enters the system from the AFL tanks via gravity to the pump station (pipe unseen). 2- The 3 pumps that will distribute the water to the other tanks/irrigate the AFL grounds. (1 pump was installed as part of the scheme and other 2 already existed). The white boxes on top are the variable speed drives. 3- A pressure vessel to assist in the maintenance of pressure in the distribution line. 4- Particle filter 2. 5- UV disinfection unit. Once the water has received its final treatment the water is either used to irrigate the AFL grounds or is stored in one of the 7 additional tanks built by the scheme. The tanks are located in the Sportspark (4 tanks including one each for baseball, softball, athletics, and soccer), Anne Aquilina Reserve, Kareela Reserve, and Nurragingy Reserve to be used for watering the sporting fields and for flushing toilets located at these facilities. Figure 7 below illustrates the set out of the treatment system in the AFL pump room. Starting from the top right to the middle left and then from the bottom left to middle top. Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 15 Figure 7: A diagram of how the AFL pump room treats the water. Control of the system Council has commissioned the installation of a SCADA (Supervisory Control and Data Acquisition) system, which is a computer system that gathers and analyses real time data to control the whole system. All of the pumps, monitoring equipment, disinfection units, tank/storage levels and filters send information to the SCADA system that stores the information, sends the information to a server in Council (every 5 minutes), and can perform analysis to determine faults or issues with the system. If an issue occurs it will send alerts to the officer responsible for management of the system, to rectify. The SCADA system also allows Council to remotely access the controls of the pumps and determine the water levels in the storages. This allows the officer to remotely turn pumps on and off from their office rather than having to go out to site (saving time and money). The SCADA system also collects data on the volume of water produced by the scheme and the amount of electricity used by the scheme. Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 16 Photo 11: The SCADA system with computer interface. 2.4. Project status Currently the scheme has been built and commissioned. Council is currently monitoring the quality of the water produced by the scheme to ensure that it meets the Australian guidelines for water recycling and provides consistent results. Once this occurs the scheme will be officially turned on for use. Once the scheme is fully operational Blacktown City Council will manage the scheme for a further 6 to 12 months collecting data on operational and maintenance costs to determine how the scheme will be managed in the long term. In the long term the scheme will either be managed in-house by Blacktown City or managed by a private operator. Under both management systems, the user of the water (Blacktown City or Blacktown Venue Management) will be billed per KL of water used, similar to Sydney Water, except if the private operator was chosen they would pay a dividend back to Council for asset hire. If Blacktown City is to manage the system the users of the water will be charged per KL used and the funding generated will be used for maintenance, operation, and replacement of all assets acquired for the scheme. The main objective of the management will be to make the scheme financially sustainable, as it will not rely on external sources to maintain its operation and maintenance. If the scheme generates a surplus, this money will be reinvested into the scheme to improve efficiencies (i.e. increasing the storage sizes to increase demand met), supply the water to another user (potentially external to Council), or to build a new scheme elsewhere. Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 17 3. PROCESS AND METHODS 3.1. Project governance: (e.g. steering committee, project team and key stakeholders) After the managed aquifer recharge project was cancelled and the Australian Government agreed on the new above ground stormwater harvesting project a steering committee was established. This steering committee included officers from the following Council departments: - Asset Design Asset Construction Civil and Open Space Maintenance Natural Areas Sport and Recreation Blacktown Venue Management (operator of the Sportspark). And external stakeholders the Western Sydney Parkland Trust (NSW Government). The Steering Committee meeting were held every 2 to 4 weeks during design and every 4 to 8 weeks during construction. The steering committee discussed components of the project such as: - System design Suitability of site Maintenance and operation Safety (WHS) Risk assessments Construction staging and progress Procurement etc. The main project team included: - Catchment Projects Officer Waterways Rehabilitation Officer Senior Drainage Engineer Senior Construction supervisor. 3.2. Project activities and conduct This project has followed Blacktown City Council’s strict procurement protocols. All quotes were approved by either the Manager of Asset Design or Director of City Assets and all tenders were approved in Council meetings. Tenders included: - System Design – Parsons Brinkerhoff (PB) Pty Ltd was awarded the contract for scheme design using the Local Government Procurement Panel. PB designed the majority of the scheme including all open water storages, creek works, pump stations, and provided tender requirements for the Mechanical and Electrical tender. PB also developed the REF and assisted with acquiring the approvals from the NSW office of water as well as construction supervision. Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 18 - - - Mechanical and Electrical – which included the supply, installation and commissioning of all pumps, monitoring equipment, electrical connections, communications and data storage. The contractor that provided these works was Itech Corporation Pty Ltd and subcontractor Neverstop Water Harvesting Pty Ltd. Construction – the construction of the different civil components were conducted by 2 contractors that performed the works under Council’s Civil Construction Tender of rates. The contractors that completed the works were Jay and Lel Civil Contractors Pty Ltd and J and G Excavations and Asphalting (NSW) Pty Ltd. Vegetation installation and maintenance – the scheme required extensive planting and maintenance works of the harvest storage ponds and treatment wetland. Dragonfly Environmental Pty Ltd performed these works and was procured through Council bushland regeneration and revegetation tender schedule of rates. Other major contracts included: - Installation of floating wetlands – Harris Environmental Pty Ltd; Smart meter installation – Watersave Pty Ltd; Installation of distribution pump and other fittings – Neverstop Water Harvesting Pty Ltd; Water quality risk assessment – Water Futures Pty Ltd; Water quality laboratory analysis – SGS Australia Pty Ltd; and Construction and supply of the tilting weir - Australian Water Engineers Pty Ltd. Blacktown City Council plant nursery provided all the plants for the project. 3.3. Water quality management The scheme is collecting polluted stormwater from an urban creek and runoff from the Sportspark. The main pollutant that is of particular concern to the health of the users of the sport facilities is the total pathogen content of the water. During the water quality risk assessment completed by Water Futures Pty Ltd a number of risks were raised and a number of solutions to these risks were created and installed. To meet the required standards for irrigation and flushing toilets set by the Australian Guidelines for Water Recycling this scheme is treating the polluted stormwater via the following treatments: - Detention time in ponds of over 72 hours = 0.5 to 2 log reduction Detention time in wetland of over 48 hours = up to 2 log reduction Chlorine dosing = 2 to 6 log reduction Particle filters (improves effectiveness of UV filter) UV filter = 2 to >4 log reduction Total log reduction range = 6 to 14 Overall the scheme has been designed to treat the water for unrestricted access as there will be occasions when the maintenance staff might be in direct contact with the water by hand watering the fields and by irrigating when there are users on site. For this reason the water quality management plan has been developed and training will be provided to all users of the water. This training will establish safe work instructions and provide information of when and where the water is to be used. Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 19 There is also going to be substantial amounts of signage warning the users of the facilities that the irrigation water is not potable water and should not be consumed. 3.4. Stakeholder and Community Consultation During the design phase of the project Council consulted heavily with the Western Sydney Parklands Trust. The Trust own some of the reserves that will be supplied treated stormwater for irrigation (Council leases these areas from the Trust) and the distribution line crossed over their land. The Trust agreed to the project and believes that securing an alternative supply of water is beneficial to the survival and longevity of the sporting fields. The Trust are also going to consider using the harvested stormwater as an irrigation supply for future sporting fields being developed to the south of Anne Aqualina Reserve. Council also visited a meeting of the Blacktown and District Environment Group to discuss the project. At the meeting Council presented its intentions of using the existing infrastructure and assets at the BISP for the project. The group agreed that the project had merit and can be seen as having a positive impact on the environment and the significant bushland located next to the BISP. During 2013 Council conducted a community consultation forum in regards to catchment management in the Angus Creek catchment area. During the forum Council Officers indicted that the scheme was to be built in the near future and the community were very supportive of the idea and believe it should be occurring more often throughout the LGA. Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 20 4. PROJECT ASSESSMENT 4.1. Objectives and key performance indicators The key objectives of the project are to: 1. Provide a secure ‘fit-for-purpose’ water supply to significantly reduce reliance on drinking water for irrigation use at Blacktown International Sports Park, Anne Aquilina Reserve, Kareela Reserve, Nurragingy Reserve and Charlie Bali Reserve: The scheme is delivering on this objective as it is supplying ‘fit-for-purpose’ water to all the reserves listed above. The water is to be used for irrigation and toilet flushing at these facilities. For the water to be fit for purpose Blacktown City ensured the scheme would provide high quality water by using both chlorination and a UV filter to remove pathogens that are harmful to human health. 2. Identify that the stormwater quality and volume is sufficient to ensure long-term sustainability of Blacktown International Sports Park’s revenue generating and employment activities and for environmental flows: Extensive modelling of the volume and quality of stormwater produced by the scheme has been undertaken as part of the design of the scheme. This modelling, when excluding base/environmental flows in Angus Creek (above 10 litres per second) estimated that in an average rainfall year the security of supply is approximately 85%. During a dry period the scheme should still produce 73% of the demand. It is also predicted the price of the harvested water would cost less than the potable water supplied by Sydney Water. Therefore Blacktown Venue Management (the operator of the Sportspark) revenue will increase as less funding is being spent on potable water which will increase employment opportunities as there will be more funding available for maintaining and upgrading facilities. 3. Promote the development and sustainable use of alternative water supplies in the urban environment through education and dissemination of project information; The scheme has developed education material in the form of an information brochure that is distributed during community events and on Council’s website. Additionally there will be interpretive signage installed in the Sportspark and throughout the Angus Creek catchment to inform the residents that the catchment is now a stormwater supply catchment for irrigation. Blacktown City has also delivered a report at the Institute of Public Works Engineering Australasia Sustainability in Public Works conference in Tweed Heads July 2014 and the NSW Stormwater Industry Association conference in Canberra July 2014. The report titled “Improving an urban creek by taking the water away” (Birtles et al, 2014) describes how Blacktown City Council is potentially going to improve the condition of Angus Creek Downstream of the harvesting point by removing the harmful peak flows that cause erosion and flush biota and habitat downstream. Council plans on presenting the finding of the project once real data on the performance of the scheme is collected. Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 21 4. Maintain environmental benefits through integrated water cycle management and water sensitive urban design (WSUD): The scheme will have an integrated water cycle management plan developed before the scheme is in full operation. This plan will highlight how the scheme is to be managed to maximise harvesting potential, improving water quality when possible, and outline potential opportunities to improve the performance of the scheme. 5. Advocate and address climate change: Predictions for the impact of climate change on Western Sydney suggest that the temperature will on average be hotter with a higher frequency of days above 40 degree Celsius and longer draughts. This scheme addresses the need to have an alternative water supply when there is a drought allowing Blacktown Venue Management and Council Officers to irrigate the sporting fields even when water restrictions apply. 6. Sustain Council’s natural and constructed assets and maintain desired level of service provision: The scheme is to collect revenue by billing the users of the water and ring fencing this funding for maintenance of the assets created by the project. The predicted funding to be generated by the scheme will allow maintenance of the assets (both natural and constructed) to the desired level of service and allow for replacement of assets once they require replacement. 7. Promote improved water equity. The water being harvested by the scheme can be used by any of the reserves as long as there is water available. No reserve will receive a benefit over another. 4.2. Project finance This section provides information about the funding received and expenditure as part of both the managed aquifer recharge scheme and the current scheme. Over the length of the project the main funding sources were from the Australian Government from the National Urban Water and Desalination Plan grant, the Environmental Stormwater Management Program from Blacktown City Council, and the Waste and Sustainability Improvement Program grant from the NSW Government. Overall the scheme received $6,028,289 in funding and has currently spent $5,357,306. Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 22 Money coming in via grant and Environmental Stormwater Management Program is provided in Table 1 below. Please note that GRANT refers to the Australian Government grant funding, WASIP refers to the NSW Governments Waste and Sustainability Improvement Program grant, and ESMP refers to Blacktown City Councils Environmental Stormwater Management Program. 2010/11 $130,000 WASIP ESMP GRANT TOTAL $130,000 2011/12 $143,000 $305,000 $477,900 $925,900 2012/13 2013/14 2014/15 $730,000 $316,500 $1,046,500 $1,170,000 $1,118,100 $2,288,100 $1,337,789 $300,000 $1,637,789 TOTAL $273,000 $3,542,789 $2,212,500 $6,028,289 Table 1: The funding allocated to the project from 2010 to 2015. Expenditure from these funding sources, including financial years, includes: Expenditure Grant TOTAL $43,248 $43,248 $282,829 $282,829 $57,893 $533,249 $591,142 $716,530 $2,119,963 $2,836,493 $1,629,671 $300,000 $1,929,671 $2,346,201 $2,419,963 $4,766,164 TOTAL COMBINED $265,065 $2,879,741 Table 2: The expenditure of funding from 2011 to 2015. $ 2,212,500 $ 5,357,306 MAR Scheme 2011/12 2012/13 Sub Total MAR Scheme Surface Scheme 2013/14 2014/15 Sub Total Surface scheme WASIP ESMP $57,893 $207,172 $265,065 The project has therefore been built within budget. Grant funds and WASIP funds have been completely expended. There is still $670,983 from ESMP funds to be expended. Current commitments total $60,937 and include: $5,043 GHD for biological water quality monitoring; $5,063 Parsons Brinckerhoff for modelling of different maintenance performance standards; $2,256.36 Water Save Australia for supply and installation of SMART Water Meters; $68.09 Bunnings for rainwater harvesting wireless water level guage; $12,976.42 SGS Australia for physical and chemical water quality monitoring; and $35,530 Dragonfly Environmental for wetland plants establishment and maintenance. Note Council in 2014/15 allocated funds into the ESMP account for future commissioning and maintenance activities. Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 23 4.3. Potable water savings achieved by the project The Scheme has the potential to harvest 200ML from Angus Creek plus the runoff collected from the Sportspark sporting grounds. But this total is reliant on the end users and the amount of rainfall received during the year. 4.4. Levelised cost of water supplied as a result of the project In this report the levelised cost of water supplied by the scheme is calculated by dividing the cost of operating and maintaining the scheme, including asset renewal, by the amount of water produced or saved. This excludes the capital costs. It is predicted that the cost to maintain and operate the scheme would be $358,250 per year. If the scheme can produce 200,000KL this means that the levelised cost water is $1.79/KL. If not all 200ML is harvested this makes the water more expensive as only 0.5% of the operation and maintenance cost is variable with the amount of water harvested, including electricity and chlorine. It was been worked out that the scheme only becomes financially better off than using Sydney Water when 165ML of stormwater is harvested, see the graph below. $8.0 Average cost of harvested water in dollars/KL average cost in dollars per KL $7.0 $6.0 $5.0 stormwater harvesting dollars/KL sydney water dollars/kL $4.0 $3.0 $2.0 $1.0 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135 140 145 150 155 160 165 170 175 180 185 190 195 200 $0.0 ML harvested per year Figure 8: A graph indicating the cost of harvested stormwater in relation to Sydney Water. This cost above only takes into account Sydney Water usage charge and doesn’t include the sewer usage charge and the other fixed charges. The predicted cost of using 200ML of Sydney Water potable water supply including all service charges is approximately $686,400, under the stormwater harvesting scheme it will only cost $357,120 creating a saving of $329,280. But as the scheme is not supplying 100% of the water demand it will still rely on Sydney Water for at least 5 % of the demand, therefore the fixed charges are still required as the Sydney Water supply can’t be disconnected. Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 24 If the cost of potable water increases the cost savings produced by the scheme would increase. The predicted operation and maintenance cost is estimated using a 20% contingency and the largest cost is the removal of sediment from the open water bodies. If the sediment can be recycled or used elsewhere instead of being disposed of in a waste facility it would save approximately $100,000 from the maintenance budget, which will bring down the cost per KL significantly. 4.5. Amount of GHG emission offset The greenhouse gas emissions resulting from the operation of the scheme have been evaluated. The use of electrical pumps to transfer water between the site of the offtake, to the treatment systems and for distribution around the park will be the primary source of emissions. Estimations of the pump power requirements have been made on the basis of calculated flows, calculated heads (including system head losses) and pump efficiencies obtained from the manufacturers. Based on the expected average yields, the total estimated average annual energy requirements for the operation of the pumps is 42,745kWh per annum. The National Greenhouse Accounts Factors workbook (Department of Climate Change, 2014), provides Scope 2 emission factors for the consumption of electricity for each state. For NSW, each kilowatt hour (kWh) results in Scope 2 emissions of 0.86kg CO2-e. On this basis, the emissions associated with the pumping for the scheme in an average year are estimated to be 36.76t CO2e/annum. The emissions estimated above only account for the pumping energy requirements, and it is recognised that there will be additional energy requirements to power the instrumentation and controls associated with the scheme. However, the power requirements for these are relatively small. Blacktown City Council will offset the greenhouse gas emission produced by the scheme through installing solar panels, which result in zero operational greenhouse gas emissions. Maintenance of the scheme will involve regular (monthly) inspections and will therefore contribute (albeit in a small way) to Council’s greenhouse gas emissions associated with the use of a vehicle to inspect the sites. Assuming that the Council uses diesel vehicles, with an average fuel efficiency of 15L/100km (worst-case scenario) and that each lot of monthly inspections involves a maximum of 50km driving, the total fuel usage for maintenance purposes is estimated to be 90L/year. The National Greenhouse Accounts Factors workbook (Department of Climate Change, 2009), provides Scope 1 and Scope 3 emissions for the combustion of fuel for transport purposes. The stated energy content of diesel is 38.6GJ/kL, with total emissions of 74.5 kg CO2-e/GJ. On this basis, the emissions arising from the monthly inspections of the sites are estimated to be 207.1kg CO2-e /annum. These emissions will be offset by the planting of trees around the sites to maintain community amenity and provide shade over the wetland to minimise evaporative losses. The carbon offset gained by the planting of trees varies depending on location, species of tree, soil type and type of planting. Approximately 197 trees would be required to offset the emissions from the maintenance inspections over the life of the scheme. Analysis of the emissions associated with the scheme shows that the scheme, results in a small net reduction in carbon dioxide emissions of approximately 567.2 t CO2-e per annum. The scheme can result in the use of harvested stormwater for the sustained substitution of up to 200ML of water Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 25 from the Sydney Water mains distribution system for non-potable use in an average rainfall year. The scheme is essentially a carbon sink. The significantly lower emissions are a result of using the wetlands to enhance the water quality (as opposed to energy intensive potable water treatment plants) and relatively smaller pumping distances. The scheme has therefore been demonstrated to be carbon negative. 4.6. Other environmental benefits Blacktown City Council as part of the design process has created water flow models that are showing eco-hydrological outcomes expected for the receiving downstream environment. Council is expecting that the data collected by the scheme will demonstrate that the creek downstream of the harvest point at least maintains its current ecological condition with potential for improvement. This infrastructure project is integrated into the framework of restoring natural environments. By undertaking rigorous modeling, we estimated the pre and post development conditions of the creek and used this to assess the impact of the project. There is however, a strong need to link the hydrological work undertaken with a hydraulic model so that environmental flows impacts can be better predicted. This would ordinarily be undertaken as part of environmental flows assessment project. Excessive stormwater flows from urban areas greatly impact the health of freshwater creeks in Western Sydney. Knights & McAuley (2009) describe criteria for sustainable stormwater harvesting projects. The Project was designed to harvest stormwater to irrigate sports fields to the benefit of the local community whilst ideally also benefitting local hydrology and eco-hydraulics. This particular approach has specific requirements to ensure success. Large storage areas and significant pumping capacity is required to enable water to be harvested quickly from the creek when the rainfall events occur. It is acknowledged that the sportspark site provided an excellent opportunity for this storage as existing open water bodies were able to be excavated further to provide immediate storage before the water is treated. In more densely urbanised areas this may provide more challenging. It should be noted, however, that the treated water from the scheme is being stored in a series of seven tank locations across differing sites. This decentralised storage outcome was undertaken in favor of demolishing a series of existing tanks to gain greater capacity in the same location. The total volume of the seven locations is 1800kL and demonstrates a more flexible footprint that may provide a model for providing large storage in more confined urban contexts. Urban governments and utilities Australia wide continue to provide services for a customer base that is increasing demanding improved liveability outcomes for their cities. This project demonstrates that provision of ecosystem services (such as water supply) from the local environment, as opposed to more traditional centralised supply approaches, have the ability to also liberate multiple liveability outcomes such as improved local waterways and aesthetics for the community (Birtles et al 2013). Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 26 5. EXPERIENCE SHARING AND LESSONS LEARNT One of the main lessons learnt relates to construction of ponds, wetland and online creek works. There was a considerable amount of construction required on both online creek works as well as offline water bodies. The wet weather that occurred from December 2013 to July 2014 caused delays and subsequently other works were than delayed. Although it was predicted that the construction timeframe should only be 4 months it turned into 8 months. Therefore always allow for wet weather delays when working in or near a creek. For example during construction of the harvest storage ponds, that fill up from swales and runoff, every time there was a storm the ponds would fill up and it would take a week to drain and another week to dry out sufficiently for excavation to occur. One positive that came from this was it did show the effectiveness of the ponds for collecting runoff without it being pumped from Angus Creek. Another major lesson was the effectiveness of using a steering committee. The Steering committee was able to work around many issues that would have not been raised until the project was complete. This early intervention saved the project thousands of dollars in the long run and it provided an effective means of updating all the relevant stakeholders on progress. 5.1. Project results and outcome realisation The predicted yield of the system was originally underestimated as the storage ponds within the Sportspark, which are used as the main storage facility for the scheme, also collect surface runoff. As discussed above each storm event provides water to the ponds via runoff. The ponds also collect irrigation runoff from the AFL/cricket grounds that surround the ponds. These fields use a sandy loam media underneath the sporting surface and any irrigation or rain that drains through the media will be collected by the under drainage and be directed back into the ponds to be reused. This makes the scheme more efficient as the runoff generated from the irrigation of the AFL fields is redirected back into the storage ponds creating a cycle system. Also during heavy rain events the ponds will fill up via the swale network without the system having to pump the water from Angus Creek saving electricity and maintenance required on the pumps. During small rainfall events when the runoff volume within the Sportspark is minimal the Angus Creek pumps will transport water from the offtake pool into the storage ponds. 5.2. Major project issues One major project issue related to the design of the system, in particular the site constraints within the Sportspark. The project could not expand the existing ponds or wetlands due to the site having limited space available and due to future plans for the expansion of sporting facilities. If the project was allowed to expand the harvest storage ponds it would have increased the overall capacity of the scheme to harvest more stormwater. The design of the ponds and other features required a number of reviews and extensive consultation with the managers of the Sportspark and other users. Another major project issue was related to acquiring the required approvals from the NSW Office of Water. Blacktown City Council first had to seek approval to construct the creek works that diverted water from the creek into the offtake pool. This approval process, although drawn out (over 6 months to approve plans), was satisfactory and Council acquired the required works approval. Once the works approval was granted Council was also required to purchase “Unit Shares” from the Lower South Creek Management Zone to extract stormwater for the scheme which was set out in the Water Sharing Plan set out in the Water Management Act 2000. One unit share is equivalent to 1 Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 27 Megalitre (1 million litres or ML) of water from the creek, therefore Council was required to contain 200 unit shares and attach them to the current water extraction license held by Council. To acquire these unit shares Council produced and ran a tender that was advertised in several local papers promoting that Council was willing to purchase any excess or unwanted unit shares that land owners within this particular management zone might have. The tender ran for 4 weeks yet no one submitted a response. The privacy policy within the NSW Office of Water restricted Council from accessing license holder information and therefore finding license holders without spending a large quantity of funding was impossible. Instead of the NSW Officer of Water assisting Council in finding license holders a decision was made by the NSW Office of Water to exempt Council from purchasing the unit shares all together. This process was unsatisfactory as Council was forced to spend considerable time and funding into tendering and modeling to show that the scheme was actually benefiting the environment through reduced peak flows and improvements in water quality. Forcing local governments and other water supply authorities that are willing to harvest stormwater from an urban creek to purchase unit shares will potentially make any stormwater harvesting and reuse project financially unfeasible. Unit shares regularly sell in other management zones for approximately $1,000 to $1,500 per share. Therefore if this scheme was forced to purchase the unit shares it could have added $200,000 to $300,000 to the overall cost of the scheme which may have made the project financially unfeasible. It is Blacktown City Council’s perspective that the NSW Office of Water should consider modifying the water sharing plans or the Water Management Act 2000 to permit harvesting from urban creeks without having to purchase unit shares as long as base flow is not harvested and the downstream environment is considered. There are considerable benefits that can be made to the condition of urban creeks by removing some of the damaging flows that are created in small to medium rain events. This scheme is also conducting extensive monitoring of upstream and downstream environments to prove whether this scheme is going to have a positive or negative impact to downstream environments in the long term. From research it is predicted it will have a positive impact but little detailed research has occurred regarding stormwater harvesting in Sydney. Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 28 6. PROJECT FUTURE The scheme is currently in the verification phase where the water quality is being monitored to ensure it meets the correct standards so it’s fit for purpose. This phase is predicted to take 3 months and the scheme should be fully operational before September 2015. Blacktown City Council Design and Development section will maintain the scheme for a period of at least 12 months post verification (that is 2015/16 financial year). The manager of the scheme will use both Blacktown City Civil and Parks Maintenance staff and specialist contractors to maintain the scheme to ensure the water is fit for purpose and all components are maintained properly. At the same time data will be collected on scheme performance, operation and maintenance costs, time required for management etc. This will provide background data so that Council can make decisions on how the scheme is to be maintained in the long term. After this initial maintenance period Council will need to make a decision on whether the scheme should be maintained in-house (business as usual) or if an external company (private water authority) is engaged to maintain the scheme in the long term. There are benefits and disadvantages for both maintenance models. Regardless of who maintains or operates the scheme there will be an annual report to Council providing details about revenue raised, allocation of funding, scheme performance, elements to improve, and recommendations. Blacktown City Council is currently planning on building more stormwater harvesting and reuse schemes as the benefits of these schemes are being realized. With the cost of potable water set to increase Council is realizing the economic, environmental and social benefits gained by using stormwater harvesting over potable water. Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 29 7. CONCLUSIONS The Blacktown Stormwater Harvesting and Reuse Scheme will provide a sustainable fit for purpose water source for the Sportspark and surrounding reserves. This scheme has also acted as a pilot project for Blacktown City Council to consider the feasibility of further integrated water management projects that improve water quality and hydrology thorough water harvesting and reuse. Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 30 ATTACHMENTS Audited financial statements prepared in accordance with Australian Accounting Standards Blacktown Stormwater Harvesting and Reuse scheme – Final Report Page 31