12
Pimpama Coomera Recycled Water Scheme Quarterly Public Report April to June 2017
Pimpama Coomera Recycled Water Scheme
Quarterly Public Report April to June 2017
Table of contents
1 Introduction .......................................................................................................................................... 3
2 Reporting .............................................................................................................................................. 3
3 Scheme description ............................................................................................................................ 3
3.1 Scheme location .......................................................................................................................... 3
3.2 Source of recycled water ............................................................................................................. 4
3.3 The treatment process ................................................................................................................ 4
3.4 Recycled water supply ................................................................................................................ 4
3.5 Recycled water use ..................................................................................................................... 5
4 Recycled water quality monitoring .................................................................................................... 5
4.1 Results for period ........................................................................................................................ 6
4.2 Non-compliances ........................................................................................................................ 6
4.2.1 Water quality criteria .................................................................................................... 6
4.2.2 Annual value ................................................................................................................ 7
5 Prescribed incidents ........................................................................................................................... 7
6 Transitioning of scheme ..................................................................................................................... 7
7 Contact details ..................................................................................................................................... 7
8 Appendices .......................................................................................................................................... 8
8.1 Appendix A Pimpama Coomera dual reticulation plan................................................................ 8
8.2 Appendix B Results of non-compliance with water quality criteria .............................................. 9
8.3 Appendix C Results of non-compliance with annual value ....................................................... 10
1 Introduction The City of Gold Coast is required under the Water Supply (Safety and Reliability) Act 2008 S.274 (C) to provide public reports relating to recycled water schemes that are suppled to premises by way of dual reticulation. As such this report fulfils the legislative requirement for the reporting period, 01 April to 30 June 2017.
Class A+ recycled water is being supplied to dual reticulated homes and businesses in the Pimpama Coomera region. This is being done through a separate water network. The network provides residents Class A+ recycled water for flushing toilets, watering gardens and other outside use.
The recycled water treatment plant at Pimpama produces Class A+ recycled water, which is the highest classification of recycled water for non-drinking purposes.
Currently there are over 9,000 homes and businesses in the Pimpama Coomera region with around 6700 of these homes connected to the recycled water system.
2 Reporting The Pimpama Coomera Recycled Water Scheme (the Scheme) was originally approved by the Office of the Water Supply Regulator (the Regulator), Department of Energy and Water Supply (formerly Department of Environment and Resource Management) on 4 November 2009. The Scheme is described in the Pimpama Coomera Recycled Water Management Plan.
In accordance with Section 274 (6) (3) of the Water Supply (Safety and Reliability) Act 2008, the City of Gold Coast is required to prepare and make available, quarterly public reports detailing:
The (class A+ recycled water) scheme.
Results of water quality monitoring carried out.
Details of information given to the Regulator (Office of the Water Supply Regulator).
The purpose of this reporting is to provide transparency and to ensure the public is informed about the recycled water it receives. This report is for the period 01 April to 30 June 2017.
3 Scheme description
The Pimpama Coomera Recycled Water Scheme (Reference Number SRN00003) is the scheme described in the Pimpama Coomera Recycled Water Management Plan, version 7, dated 15 January 2016. A summary of the scheme is provided below.
3.1 Scheme location
The Pimpama Coomera Recycled Water Scheme region currently incorporates supply to the following suburbs (or part thereof):
• Pimpama
• Coomera
• Upper Coomera
• Willowvale
• Hope Island
Details of dual reticulation connection status in these areas are shown in Appendix A.
3.2 Source of recycled water
High quality Class A+ recycled water is produced from sewage collected from the Pimpama Coomera region and treated at the Pimpama Recycled Water Treatment Plant (RWTP). The sewage flowing to the plant is primarily domestic in origin. The flow from non-residential premises comprises of approximately 11% of the total wastewater flow to the plant. The sewerage network is designed as a 'smart sewer system' that will minimise the volume of inflow entering the sewerage network, reducing the energy required to treat sewage, meaning fewer greenhouse gas emissions.
3.3 The treatment process
Rigorous treatment, monitoring, testing and quality assurance systems have been put in place to ensure Class A+ recycled water meets environmental and health guidelines. Figure 1 summarises the recycled water treatment process at the Pimpama RWTP.
Figure 1. The Class A+ recycled water treatment process
3.4 Recycled water supply
All Class A+ recycled water users are supplied through a dual reticulation system (direct pipeline). The network is serviced by the Peanba Park Road Reservoir.
A tanker fill site is located at the Pimpama RWTP for customers that require recycled water but are not in a dual reticulation area. Recycled water supplied from this tanker fill site is classified by the City of Gold Coast as Class C, irrespective of whether or not it has been treated to Class A+ or B and is monitored accordingly.
3.5 Recycled water use
Class A+ can be used for:
• irrigation of lawns, gardens, fruit trees and vegetable crops (fruit and vegetables should be rinsed in drinking water before consumption)
• flushing toilets
• washing cars, houses and other similar outdoor uses
• filling ornamental ponds, water features and fountains
• approved commercial, construction and industry uses
• fire fighting (except fire sprinkler systems)
Class A+ cannot be used for:
• drinking
• cooking or kitchen purposes
• personal washing such as baths, showers, bidets and hand basins
• domestic evaporative coolers
• washing clothes
• swimming pools and spas
• recreation, such as playing under sprinklers and water toys
• a water source for pets and livestock
• filling rainwater tanks or other storages
4 Recycled water quality monitoring The City of Gold Coast undertakes a suite of recycled water quality tests to ensure the final product meets stringent water quality criteria. The tests are conducted using on-line monitoring and routine test procedures.
The treatment standards required for the Pimpama Coomera RWTP Class A+ recycled water are summarised in Table 1.
Table 1. Water Quality Requirements for Class A+ Recycled Water1
Parameter Microbiological Criteria2,3
Viruses • F-RNA Bacteriophage: <1pfu/100ml 95th percentile over a 12 month
period
• Somatic coliphage: <1 pfu/100ml 95th percentile over a 12 month period
Bacteria • Escherichia coli: <1 cfu/100ml 95th percentile over a 12 month period
Protozoan Parasites • Clostridium Perfringens: <1 cfu/100ml 95th percentile over a 12 month period
Other Requirements
• Turbidity: < 2 NTU 95th percentile over a 12 month period
• Chlorine residual: >0.5 mg/L 95th percentile over a 12 month period at the network monitoring points (points of supply)
• Chlorine residual: >2.5mg/L 95th percentile over a 12 month period at the point of supply to the distribution network at the RWTP
Note: 1. From Public Health Regulation 2005 and in accordance with the Information Notice for the Decision (15 January 2016) 2. cfu = colony forming units 3. pfu = plaque forming units
Ongoing verification monitoring of Class A+ recycled water is undertaken at the Pimpama RWTP prior to supply and at three fixed monitoring sites located throughout the distribution network. The three fixed monitoring sites are located at the following locations:
• Dayflower Street • Billinghurst Crescent • Ceil Circuit
On 16 February 2017, the City received communication from the Regulator stating that the City is no longer required to undertake monitoring under condition 7.10 of the Information Notice for the Decision. The City was instructed by regulator to undertake operational monitoring instead and ensure the quality of the non-drinking water supplied does not cause a public health risk.
On 29 March 2017, the City requested permission from the Regulator to not report non-compliance with water quality annual values (condition 7.15) for condition 7.10 each month if there were no failures of the annual value during that month. The Regulator subsequently accepted the request from the City and confirmed that this was acceptable as per condition 7.15.
Ongoing verification testing of Class C recycled water is undertaken at the tanker fill point at the Pimpama RWTP and at the corner of Hope Island Road and Monterey Keys Road, Hope Island in the network. The tanker fill point monitoring point is also used for verification of Class A recycled water used onsite for service water.
4.1 Results for period
The required number of samples was collected during the period 01 April to 30 June 2017 at the appropriate frequency and for the required parameters.
Table 2 details the water quality parameters tested during the period and details frequency, sample count and regulated standard required. These results are for samples taken at the point of supply – which is at the Pimpama RWTP.
Table 2. Quarter 2 verification monitoring of recycled water at the point of supply Summary of Water Quality Monitoring
Sample Frequency
Sample Count Min Max Mean %
Compliance Regulated Standard
Free Chlorine Daily* 80 3.4 5.8 4.3 100% >2.5 mg/L found in 95% of samples taken for a 12 month period
Clostridium perfringens Weekly 13 <1 1 <1 98%
<1 cfu/100mL found in 95% of samples taken for a 12 month period
E. coli Weekly 13 <1 <1 <1 100% <1 cfu/100mL found in 95% of samples taken for a 12 month period
F-RNA bacteriophage Weekly 13 <1 <1 <1 100%
<1 pfu/100mL found in 95% of samples taken for a 12 month period
Somatic Coliphages Weekly 13 <1 <1 <1 100%
<1 pfu/100mL found in 95% of samples taken for a 12 month period
Turbidity Daily* 80 0.09 0.55 0.25 100% <2 NTU found in 95% of samples taken for a 12 month period
* Tests for free chlorine and turbidity are performed on a daily basis when there is delivery of A+ recycled water to the distribution network.
4.2 Non-compliances
4.2.1 Water quality criteria
There were no non-compliances with water quality criteria during the period and retesting was not required. Full details of any non-compliance with water quality criteria are provided in Appendix B.
4.2.2 Annual value
The regulator was notified on 28 February 2017 for the non-compliance with the free chlorine annual value. Since February 2017, there have been no failures of the annual value and subsequently a report to the regulator is not required each month as per condition 7.15.During this quarter, 94-96% of the samples for 12 month period were greater than 0.5mg/L. Full details of non-compliances with the annual value are provided in Appendix C.
5 Prescribed incidents There were no prescribed incidents during the quarter.
6 Transitioning of scheme
The City resolved on 12 December 2013 to discontinue implementation of dual reticulation in all areas of the Gold Coast. The City will be staging the transition of the Pimpama Coomera Class A+ recycled water scheme which is due for completion in mid-2017.
The City did not make the decision to transition the Class A+ recycled water product lightly. Significant investigation of the recycled water system was undertaken including:
• costs to operate and maintain the recycled water network • the current recycled water and potable water demand • the future recycled water and potable water demand for the Gold Coast • the infrastructure yet to be installed by the City, developers and home owners.
The high cost of the Class A+ recycled water scheme for the City and the Gold Coast community outweighs the value to the city. Properties in the region will have minimal disruptions to service during the transitioning period. There is no immediate impact to customers in the Pimpama Coomera region. Affected customers were initially notified by letter and will continue to receive updated communications from the City over the transitioning period.
The transition or “switch over” to a non-drinking supply for toilet and outdoor irrigation use will occur once the Class A+ recycled water scheme has ceased. There will be no other impacts to properties currently receiving Class A+ recycled water. For properties that are in the region and are not currently being supplied with Class A+ recycled water, there will be no impact as these properties are already receiving non-drinking water through the dual reticulation infrastructure. Refer to Appendix A for more detailed map of the transitioning process.
A transition plan (schedule) has been developed and further work is being undertaken on the transitioning of the scheme. This plan will provide our customers with more detailed information about the transition.
For up to date information on the Class A+ transitioning, visit our website cityofgoldcoast.com.au/recycledwater.
7 Contact details For further information regarding the Pimpama Coomera Recycled Water Scheme, Pimpama Coomera Recycled Water Management Plan or the Pimpama Coomera Waterfuture Master Plan, please contact the Coordinator Product Quality by phoning 5582 8186 or by emailing [email protected].
iSpot 63274112, version 1 Pimpama Coomera Quarterly Public Report – April to June 2017 Page 8 of 12
8 Appendices
8.1 Appendix A Pimpama Coomera dual reticulation plan
iSpot 63274112, version 1 Pimpama Coomera Quarterly Public Report – April to June 2017 Page 9 of 12
8.2 Appendix B Results of non-compliance with water quality criteria The table below details non-compliances with water quality criteria notified to the Regulator.
Date non-compliance of annual
value notified to Regulator
Parameter Testing Frequency
Regulated standard
(units)
Details of sample/s that caused noncompliance of water quality criteria
Circumstances that gave rise to the noncompliance
Any action taken, or to be taken, to correct the
noncompliance
Measures taken to prevent the
noncompliance in the future and actions taken
at the direction of the Regulator
Actual value
Date/s sample
collected
Details of samples that contributed to
noncompliance with regulated standard, including short-term & resample values.
There were no non-compliances with water quality criteria for the reporting period.
iSpot 63274112, version 1 Pimpama Coomera Quarterly Public Report – April to June 2017 Page 10 of 12
8.3 Appendix C Results of non-compliance with annual value The table below details non-compliance of the annual value notified to the Regulator.
Date non-compliance of annual
value notified to Regulator
Parameter Testing Frequency
Regulated standard
(units)
Details of sample/s that caused noncompliance of annual value
Circumstances that gave rise to the noncompliance
Any action taken, or to be taken, to correct the
noncompliance
Measures taken to prevent the
noncompliance in the future and actions taken
at the direction of the Regulator
Actual value
Date/s sample
collected
Details of samples that contributed to
noncompliance with regulated standard, including short-term & resample values.
28/02/2017 Free chlorine (Condition 7.10)
Weekly
95% of samples are >0.5 mg/L
88.68% of samples are >0.5 mg/L
30/08/2016
Value of sample at Ceil Cct was 0.33mg/L
Low chlorine residual is likely due to low demand for the product and consequently reducing the flow which may have contributed to the decay of the free chlorine residual.
The rechlorination facility at Peanba Park A+ Reservoir was checked for standard operation and appropriate chlorine dosing arrangements. The facility was found to be operating effectively and dosing sufficient levels of hypochlorite. Chlorine dosing at Pimpama RWTP was maintained between 3.0 mg/L and 6.0 mg/L for the majority of the time. Rainfall experienced throughout the year may have affected the demand of the product thus leading to a longer detention time in the mains and therefore a reduction in free chlorine residual.
Gold Coast City Council aim to improve water quality within the dual reticulation network through the increase of demand, which is currently being explored in a number of projects to investigate reservoir mixing dynamics and flushing station installation. The inlet pipe work in the Peanba Park A+ Reservoir was reconfigured to improve chlorine residual through increased mixing and a flushing station has been installed to improve flow through the network.
27/09/2016
Value of sample at Ceil Cct was 0.36mg/L
4/10/2016 Value of sample at Ceil Cct was 0.45mg/L
18/10/2016 Value of sample at Ceil Cct was 0.39mg/L
17/01/2017 Value of sample at Ceil Cct was 0.09 mg/L. Value of sample at Dayflower St was 0.17mg/L.Value of sample at Billinghurst Cres was 0.43mg/L. Resampled 18/01/2017 - Resample value at Ceil Cct was 0.05mg/L. Resample value at Dayflower St was 0.6mg/L. Resampled 19/01/2017 - Resample value at Ceil Cct was 2.6mg/L
iSpot 63274112, version 1 Pimpama Coomera Quarterly Public Report – April to June 2017 Page 11 of 12
Date non-compliance of annual
value notified to Regulator
Parameter Testing Frequency
Regulated standard
(units)
Details of sample/s that caused noncompliance of annual value
Circumstances that gave rise to the noncompliance
Any action taken, or to be taken, to correct the
noncompliance
Measures taken to prevent the
noncompliance in the future and actions taken
at the direction of the Regulator
Actual value
Date/s sample
collected
Details of samples that contributed to
noncompliance with regulated standard, including short-term & resample values.
25/04/2017*
Free chlorine (Condition 7.10)
Weekly
95% of samples are >0.5 mg/L
94.23% of samples are >0.5 mg/L
No samples contributed to the failure of the annual value for this month
30/05/2017*
Free chlorine (Condition 7.10)
Weekly
95% of samples are >0.5 mg/L
95.51% of samples are >0.5 mg/L
No samples contributed to the failure of the annual value for this month
27/06/2017*
Free chlorine (Condition 7.10)
Weekly 95% of samples are >0.5 mg/L
95.51% of samples are >0.5 mg/L
No samples contributed to the failure of the annual value for this month
*Reporting of annual values (condition 7.15) for condition 7.10 each month was not required as there was no failure of the annual value during the month.
