Waterproofing Port Pirie
The Port Pirie Regional Council has been working on minimising its reliance on the River Murray for several years. In 2010 Council, together with Nyrstar and funding provided by the Australian Government undertook a major water reuse project. The project involved reusing 350 ML of water per year (with the potential over time to reach 500 ML/yr) from Nyrstar’s waste water system (PET Plant), treat the water by way of a reverse osmosis plant, and make the water available for community municipal greening (100 ML/yr), with the balance being reused by industry (Nyrstar). Previously Nyrstar’s waste water was released into the ocean after treatment via its PET Plant.
Since this time Council has been seeking out additional water supplies to add to its water reuse scheme. Various studies have been conducted exploring potential sources of water other than the River Murray including:
- ASR Desktop Assessment: AGT 2007
- Crystal Brook CWMS Reuse Proposal: Tonkin Consulting 2008
- Nyrstar & SA Water Waste Water: Worley Parsons 2008
- Crystal Brook Stormwater Management Plan: Tonkin Consulting 2008
- Port Pirie Stormwater Management Plan: Tonkin Consulting 2009
- Port Pirie South Sewer Mining: Tonkin Consulting 2009
- Napperby CWMS Reuse Proposal: Tonkin Consulting 2010
- Nyrstar Water Reuse Project: 2010
- South West Drainage Scheme: Tonkin Consulting 2012
- Port Pirie Stormwater Harvesting Options: BlueSphere Initial Assessment 2012
- Port Pirie Stormwater Harvesting Options: BlueSphere Detailed Assessment 2013
- Stormwater Harvesting: Virtus Soccer Club Grounds 2013
- Port Pirie Stormwater Harvesting Yield Investigation: Tonkin Consulting 2014
A summary of these studies together with a copy of the full reports are provided below.
Unfortunately many of these studies indicate that the quality of water was poor and predominantly salinity (ground water, sewer water, stormwater) and that storage of captured water was pragmatic due to the saline ground water and high water table.
While these reports have predominantly not produced favourable results, Council continues to look at ways in which it can further waterproof the region and add to the current 100 ML/yr it recycles in the community from the Council-Nyrstar water reuse scheme.
Aquifer Storage & Recovery Desktop Assessment: AGT 2007
This report undertook a desktop assessment of the potential for Aquifer Storage & Recovery in Port Pirie. Geological & hydrogeological information associated within a 10km radius of Port Pirie was analysed using well information sourced from the Department of Water, Land & Biodiversity Conservation Drillhole Enquiry System, South Australian Resource Information Geoserver Drillhole Database, geological maps, Geographical Information Systems and through review of relevant literature.
The study found that “the prospect of a viable Aquifer Storage & Recovery Scheme in the city of Port Pirie is not considered favourable due to the risks associated with potential clogging, recovery efficiencies, limited storage capacity and typically low yields.” It also observed that “Aquifer Storage & Recovery would not be considered feasible for depths less than 50m, based on low yields observed as well as the typically clayey nature of sediments to this depth.”
Crystal Brook CWMS Reuse Proposal: Tonkin Consulting 2008
Council engaged Tonkin Consulting to investigate potential water reuse options in Crystal Brook from the town’s waste water from the Community Waste Water Management Scheme (CWMS). The report looked at a number of options including transporting waste water from the current treatment lagoons located 3.5km South of the town, into storage lagoons to be constructed closer to the town (at the old racetrack), and then reticulated through the town to the showgrounds, Adelaide Square, Jubilee Park and the School. Costs ranged from $1.4m to $2.2m to reclaim between 50 to 60 ML/yr respectively.
At the time, the cost and the unavailability of grants made the project marginal at best. As a result the project was put on hold.
Nyrstar & SA Water Waste Water: Worley Parsons 2008
In 2007/08 Worley Parsons was engaged by Nyrstar on behalf of the Port Pirie Regional Council and Southern Flinders Ranges Development Board to examine the feasibility of establishing a desalination plant to treat effluent from both the Nyrstar Process Effluent Treatment System (PETS) and the SA Water Port Pirie Waste Water Treatment Plant (WWPT).
The combined effluent yield of these plants is some 1,850 ML/yr. This was seen to represent a very significant and reliable source of potentially re-useable water; however both water sources were very saline in nature and included other potential contaminants.
The Feasibility Study indicated that a reverse osmosis desalination plant could produce some 1,350 ML/yr of treated water suitable for re-use both at the Nyrstar smelter and for irrigation of green space in particular within the city. Such a plant was estimated to cost some $10.4m to establish and would require 0.7 MW of power per annum to operate.
Ultimately, following consultation with the appropriate State agencies, a decision was made not to proceed with the desalination option for the WWTP effluent on the basis of capital cost.
Crystal Brook Stormwater Management Plan: Tonkin Consulting 2008
The Port Pirie Regional Council commissioned Tonkin Consulting to conduct a formal investigation to prepare an integrated Stormwater Management Plan for the Crystal Brook Township. The development of this Plan assists in prioritising works within the Township. The Plan was prepared in accordance with the “Guideline Framework for Uniform Catchment Based Stormwater Planning by Local Government”.
This study sets out a range of stormwater management related objectives and a plan of actions and strategies to meet the objectives. A prioritised plan of capital works has been developed. The Plan outlines the various catchments in the Township, estimated stormwater in these catchments and how these can be better managed. This report has been used as the basis for a number of stormwater reuse reports.
Port Pirie Stormwater Management Plan: Tonkin Consulting 2009
The Port Pirie Regional Council commissioned Tonkin Consulting to conduct a formal investigation to prepare an integrated Stormwater Management Plan for the Port Pirie City. The development of this Plan assists in prioritising works within the City. The plan was prepared in accordance with the “Guideline Framework for Uniform Catchment Based Stormwater Planning by Local Government”.
This study sets out a range of stormwater management related objectives and a plan of actions and strategies to meet the objectives. A prioritised plan of capital works has been developed. The Plan outlines the various catchments in the City, estimated stormwater in these catchments and how these can be better managed. This report has been used as the basis for a number of stormwater reuse reports.
Port Pirie South Sewer Mining: Tonkin Consulting 2009
In May 2009, Tonkin Consulting presented a draft Concept Design Report outlining the potential for sewer mining and water reuse in Port Pirie. A number of potential mining options were outlined, as well as distribution options for the irrigation of Council parks and gardens. This desktop study was based on previous work undertaken for SA Water and focused on areas where sewage was likely to have low salinity levels.
An annual volume in the range of 80-100 ML was considered to be the minimum yield volume for such a project to be viable, with a preference for a volume of 120 ML/yr or greater.
In order to confirm the feasibility of each option, sewer monitoring was undertaken at seven sites to rule out sites with either excessively low flow, or high salinity.
Three of the seven sites investigated offered the greatest potential for sewer mining. The performance results for these sites are provided in the reports below.
Napperby CWMS Reuse Proposal: Tonkin Consulting 2010
Council engaged Tonkin Consulting to investigate potential water reuse options in Napperby from the town’s waste water from the Community Waste Water Management Scheme (CWMS). The report looked at reusing the treated water on the nearby School oval. The Cost of this project ranged from $259,000 to $355,000 to reclaim approximately 14 ML/yr.
At the time, the cost of the project against the minimal benefit to ratepayers and the inability of the School to contribute, lead Council to put the project on hold.
Nyrstar Water Reuse Project: 2010
Port Pirie Regional Council and Nyrstar (Port Pirie), together with funding provided by the Australian Government via its National Water Security Plan for Cities and Towns collaborated to complete a major strategic water reuse project for the City of Port Pirie.
The project involved reusing 350 ML of water per year (with the potential over time to reach 500 ML/yr) from Nyrstar’s waste water system (PET Plant), treat the water by way of a reverse osmosis plant, and make the water available for community municipal greening (100 ML/yr), with the balance being reused by industry (Nyrstar). Previously Nyrstar’s waste water was released into the ocean after treatment via its PET Plant.
Council has used its 100M L/yr to irrigate Memorial Park (30 ML/yr), Memorial Oval (14 ML/yr), Woodward Park (5 ML/yr), Frank Green Park (5 ML/yr), Senate Road Sporting Complex (30 ML/yr); the Port Pirie Cemetery (14 ML/yr) and 2 ML/yr for greening, wash down, cleaning, and dust suppression, which are critical activities to reduce lead exposure in the community.
This recycled water directly replaces mains water supplied via the River Murray; assists with improving children’s health under the community’s Ten for Them project; helps facilitate economic and industry growth; as well as assisting Council to provide higher quality playing surfaces on its major ovals.
The total cost of this project was $5 million and was funded via the Australian Government ($2.5 million); Port Pirie Regional Council ($1 million) and Nyrstar ($1.5 million).
South West Drainage Scheme: Tonkin Consulting 2012
Port Pirie Regional Council commissioned Tonkin Consulting to investigate the requirements for a stormwater outfall to serve developable land to the South of Risdon Park South. The outfall is to follow an alignment through rural land to the West of the area and consider the benefits of incorporating a potential storage area to the West of Port Davis Road. The investigation has included hydrological and hydraulic modelling of the pre-existing catchment (prior to recent development) and the proposed future development to establish an outfall size and storage volume requirements for the developments. This report describes the analysis and provides a stormwater management strategy to protect existing and future development in the area from the 100 year ARI flood event.
Development of a stormwater reuse scheme was also considered as part of this study. These options will be considered as and when residential development occurs on this land.
Port Pirie Stormwater Harvesting Options: BlueSphere Initial Assessment 2012
Port Pirie Regional Council engaged the services of BlueSphere to undertake an initial desktop assessment into the feasibility of using traditional groundwater supply utilising local aquifers and stormwater harvesting using the Nyrstar Western Slag Dump (referred to herein as the Black Sands Emplacement Area - BSEA) for storage and retrieving it for use in Port Pirie.
This desktop assessment concluded by stating that “BlueSphere believes there is merit in pursuing both the stormwater harvesting and storage, and traditional groundwater supply [from the North-East foothills] options to a detailed feasibility assessment stage. This will provide a higher level of surety with respect to securing an alternative water supply by the target year 2020.
While the harvesting of stormwater for storage in the BSEA and later reuse for irrigation presents opportunities for positive outcomes on a number of fronts, the approach faces many technical, regulatory and community challenges and is regarded as having only a moderate likelihood of future implementation and success as a result.
By contrast a traditional groundwater supply is likely to have a higher level of initial acceptance, as the concept is well established with regulators and the wider community.”
These recommendations were accepted by Council with further works carried out by BlueSphere in 2013 to explore these options (see below for details).
Port Pirie Stormwater Harvesting Options: BlueSphere Detailed Assessment 2013
Port Pirie Regional Council asked BlueSphere to expand on their 2012 initial desktop assessment into the feasibility of stormwater harvesting in Port Pirie using the Nyrstar Western Slag Dump (referred to herein as the Black Sands Emplacement Area - BSEA) for storage and retrieving and convert this into a business case. Further consideration of the use of groundwater from the Napperby foothills was also undertaken.
The preferred option identified was to use the Black Sands Emplacement Area (BSEA) to the North of the Township as a stormwater storage and reuse basin. At present, studies have been undertaken by various consultants assessing the feasibility of certain aspects of the project with a focus on identifying any potential factors that would make the project unviable. The report found that there was no technical reason identified that would prevent the proposal from going ahead. The high level cost estimate of implementing the proposal was in the range of $20-30m with more detailed assessment and a full feasibility required. Due to the cost of the project, it did not proceed.
In relation to the use of groundwater from the Napperby foothills the report found that “significant uncertainty surrounds the ability to obtain sufficient groundwater supply in terms of yield and quality while avoiding unacceptable interference with other groundwater users. Further, yield restrictions (unless say 6 or more bores were installed adding to pipeline costs) would be expected to require substantial storage (i.e. header tanks) to fulfil estimated peak demand. It is considered that groundwater could best be seen, at this stage, as a potential supplementary source of water rather than an alternative to fulfil demand in its own right. One possible alternative is to use groundwater to supplement recharge to the BSEA which may be potentially useful in helping drought proof this facility which would rely on stormwater runoff. The installation and testing of production bores would remove much of the uncertainty and would be a logical next step. This could perhaps be put on hold until other studies are completed providing a better idea of the BSEA to meet supply requirements on its own”.
Storm Water Harvesting: Virtus Soccer Club Grounds 2013
Port Pirie Regional Council engaged the services of Tonkin Consulting to investigate water reuse options for the irrigation of the Virtus Soccer Club grounds on Magor Road Port Pirie.
This report found that the Virtus Soccer Club could meet half of its irrigation needs of 4 ML/yr by enlarging and lining the adjacent stormwater lagoon at a cost of $195,000. It is Council’s understanding that the Virtus Soccer Club used this report as the basis of a successful State Government funding application in 2015 with construction due to start soon.
Port Pirie Stormwater Harvesting Yield Investigation: Tonkin Consulting 2014
As part of the BlueSphere Stormwater Harvesting study, Port Pirie Regional Council engaged Tonkin Consulting to undertake a more detailed assessment of the potential yields from each of the three detention basins (Dead Horse Creek (DHC), Wandearah, and Moppett) and size the associated stormwater harvesting pump stations and rising mains.
This study indicated that the potential Yield from Port Pirie’s Northern water catchments were as follows:
- Dead Horse Creek 77-92 ML/a
- Wandearah Road 185-252 ML/a
- Moppett Road 90-114 ML/a
The report estimated that it would cost $4.4m to pump water from these lagoons to the BSEA at Nyrstar for storage and future reuse. This investigation also raised concerns regarding the “quality of water that could be harvested from each basin, particularly during low inflows, and its sustainability for reuse. The interaction of the saline groundwater and its impact on stormwater quality, as it may affect the yields from each of the basins, requires further investigation”.