Water Strategies Review
Share Water Strategies Review on Facebook
Share Water Strategies Review on Twitter
Share Water Strategies Review on Linkedin
Email Water Strategies Review link
About
On 21 January 2016 Council resolved:
" that Council staff brings a report to a future Council meeting with recommendations for the establishment of a community reference group to participate in the development and monitoring of Council's demand management and water efficiency initiatives and provide input to Council decisions concerning water security for the Shire."
To address Council's resolution it was proposed that Council:
1. Reviews the present Demand Management Strategy and Implementation Plan in the context of the demand reduction achieved to determine the efficacy of the Strategy and Implementation Plan (what has been done, what worked - what did not work and at what cost).
2. Reviews the present Demand Forecasts to determine the assumptions made about the reduction in demand (what has been assumed in the continued reduction in demand and is it realistic).
3. Establishes a Community Reference Group to review the assessment of the Demand Management Strategy and Implementation Plan.
4. Through the Community Reference Group, identifies additional demand management measures to be considered in updating/revising the Demand Management Strategy and Implementation Plan.
5. Analyses proposed demand management measures in terms of cost and achievability and provide the analysis to the Community Reference Group.
6. Through the Community Reference Group's consideration of the analysis, identifies additional demand management and water efficiency measures to be recommended to Council.
7. Through the Community Reference Group, identifies criteria by which the efficacy of the demand management measures can be assessed.
8. Undertakes regular reporting on performance against the criteria.
About
On 21 January 2016 Council resolved:
" that Council staff brings a report to a future Council meeting with recommendations for the establishment of a community reference group to participate in the development and monitoring of Council's demand management and water efficiency initiatives and provide input to Council decisions concerning water security for the Shire."
To address Council's resolution it was proposed that Council:
1. Reviews the present Demand Management Strategy and Implementation Plan in the context of the demand reduction achieved to determine the efficacy of the Strategy and Implementation Plan (what has been done, what worked - what did not work and at what cost).
2. Reviews the present Demand Forecasts to determine the assumptions made about the reduction in demand (what has been assumed in the continued reduction in demand and is it realistic).
3. Establishes a Community Reference Group to review the assessment of the Demand Management Strategy and Implementation Plan.
4. Through the Community Reference Group, identifies additional demand management measures to be considered in updating/revising the Demand Management Strategy and Implementation Plan.
5. Analyses proposed demand management measures in terms of cost and achievability and provide the analysis to the Community Reference Group.
6. Through the Community Reference Group's consideration of the analysis, identifies additional demand management and water efficiency measures to be recommended to Council.
7. Through the Community Reference Group, identifies criteria by which the efficacy of the demand management measures can be assessed.
8. Undertakes regular reporting on performance against the criteria.
Q&A
-
Share I believed there was a desalination plant on the Gold Coast for water security during drought. I have been recently told it does not operate that there is c=something wrong with the plant. Can you advise on this infrastructure being a viable plant and how that works in with any strategies? on Facebook Share I believed there was a desalination plant on the Gold Coast for water security during drought. I have been recently told it does not operate that there is c=something wrong with the plant. Can you advise on this infrastructure being a viable plant and how that works in with any strategies? on Twitter Share I believed there was a desalination plant on the Gold Coast for water security during drought. I have been recently told it does not operate that there is c=something wrong with the plant. Can you advise on this infrastructure being a viable plant and how that works in with any strategies? on Linkedin Email I believed there was a desalination plant on the Gold Coast for water security during drought. I have been recently told it does not operate that there is c=something wrong with the plant. Can you advise on this infrastructure being a viable plant and how that works in with any strategies? link
I believed there was a desalination plant on the Gold Coast for water security during drought. I have been recently told it does not operate that there is c=something wrong with the plant. Can you advise on this infrastructure being a viable plant and how that works in with any strategies?
Dian asked over 3 years agoIt is not really appropriate for Council to respond to your questions about the Tugun Desalination Plant because as it is a matter for Seqwater. The Tugun plant is not part of Council's water supply strategy.
Please direct any questions about the desalination plant and its operation to Seqwater at communications@seqwater.com.au.
tugun desalination plant,seqwatertugun desalination plant seqwater -
Share In early December 2019, there were high river flows recorded at the Uki gauge. Did Council release a large volume of water - over and above the daily release required to maintain supply at Bray Park Weir during the drought - from Clarrie Hall Dam? - Richard Murray at PRG meeting 24 February 2020. on Facebook Share In early December 2019, there were high river flows recorded at the Uki gauge. Did Council release a large volume of water - over and above the daily release required to maintain supply at Bray Park Weir during the drought - from Clarrie Hall Dam? - Richard Murray at PRG meeting 24 February 2020. on Twitter Share In early December 2019, there were high river flows recorded at the Uki gauge. Did Council release a large volume of water - over and above the daily release required to maintain supply at Bray Park Weir during the drought - from Clarrie Hall Dam? - Richard Murray at PRG meeting 24 February 2020. on Linkedin Email In early December 2019, there were high river flows recorded at the Uki gauge. Did Council release a large volume of water - over and above the daily release required to maintain supply at Bray Park Weir during the drought - from Clarrie Hall Dam? - Richard Murray at PRG meeting 24 February 2020. link
In early December 2019, there were high river flows recorded at the Uki gauge. Did Council release a large volume of water - over and above the daily release required to maintain supply at Bray Park Weir during the drought - from Clarrie Hall Dam? - Richard Murray at PRG meeting 24 February 2020.
BrendaH asked over 4 years agoIn the period before the high flows Council was having trouble with the valve which resulted in low flows . Subsequently it got opened to 50% at 3pm on 6/12/19 to catch up with release to maintain weir water level at Bray Park Weir. This equated to around 90ML/day.
The valve remained at 50% until 7:05am on 8/12/19 when it was closed to 28% and subsequently 26%. We also received 35mm of rain on the 8/12/19.
The opening of the valve to make up flows plus the rainfall event caused the spike in flows at Uki.
See the graph "Release Graph" in the right-hand column on this page.
-
Share 15.4.2019 Questions on Drought contingency and water supply emergency management measures and Water Quality. Following PRG meeting of the 10th April 2019, I wish to confirm that that the undermentioned document was handed to Elizabeth Seidl for consideration by the Water Strategies Review Project Reference Group when the group considers: The Hydrosphere option: ‘Drought contingency and water supply emergency management measures need to be further developed’ [Hydrosphere Six Year IWCM Review Background Paper Item 16 Para. 4/5, Paper P.37] The Hydrosphere Drought Management Strategy recommended inter alia: • Develop a Blue Green Algae Management Plan. • Install an additional mixer in the Clarrie Hall Dam to enhance the capacity, flexibility of the existing system and provide system redundancy. Council is reviewing the performance of the destratification system. The undermentioned research document was prepared by a member of the Tweed Shire Council Laboratory and was assisted by additional financial and in-kind support provided to the project by the Central Queensland University, Centre for Environmental Management, the Tweed Shire Council and the Tweed Laboratory Centre, as well as the assistance from staff past and present of the Tweed Shire Council Water Unit, the Tweed Laboratory Centre, the Bray Park Water Treatment Plant Research comparing three water bodies from the Tweed River catchment – July 2013 Phytoplankton Ecology of the Tweed River Catchment with reference to toxin-producing cyanoprokaryotes DOI: 10.13140/RG.2.1.4119.1920 Thesis for: Doctor of Philosophy, Advisor: Associate Professor Larelle Fabbro - July 2013 Sally Everson - Independent Researcher Abstract - [Summary] This research compared three water bodies from the Tweed River catchment, using a combination of field and laboratory studies. The study yielded new insights about the conditions that favour the growth of toxin-producing cyanoprokaryotes (blue-green algae). The species of interest included Cylindrospermopsis raciborskii and Aphanizomenon ovalisporum (now Chrysosporum ovalisporum) and the toxin Cylindrospermopsin (CYN). This information is important in managing risks for drinking and recreational water supplies in subtropical areas worldwide. https://www.researchgate.net/publication/304585873_Phytoplankton_Ecology_of_the_Tweed_River_Catchment_with_reference_to_toxin-producing_cyanoprokaryotes Abstract continued: “The management of human health risks in drinking water supplies is a global challenge, particularly in the context of urban population growth, increased water demands and climate change. Cyanoprokaryotes and their toxins may present a serious risk to the quality of drinking water supplies. Understanding the ecology of algal assemblages and their accompanying risks is therefore critically important for effective management of those water bodies that experience problematic cyanoprokaryote blooms.” “This project was conducted within the Tweed River catchment, a coastal subtropical area under pressure from population growth, ongoing development and climate change. The three study sites chosen in the catchment were: (1) a small artificial lake with a maximum depth of 19 m and covering an area of 2.5 hectares (Cobaki Lake); (2) a water storage facility with a maximum depth of 20 m, a destratification unit installed, and an area of 340 hectares (Clarrie Hall Dam); and (3) a flowing river with a maximum depth of 4 m (Tweed River at Bray Park). Water column dynamics, water chemistry and algal assemblages were investigated”. The conclusion of this thesis reads: “Chapter 10. Summary and Conclusions P., 203 The study showed a statistically significantly increased presence of cyanoprokaryotes in the dry warmer year, compared with the wet, cooler months of 2008. Changes in the speciation and toxicity patterns within the phytoplankton populations were also highlighted. The appearance of non saxitoxin-producing A. circinalis in Clarrie Hall Dam in the wet year did not result in a bloom, despite triggering the NHMRC high alert level for drinking water with a concentration greater than 6,500 cells mL-1. Increased rainfall resulted in reduced retention time with significant outflow of water and associated flushing of Clarrie Hall Dam. This flushing contributed to the lack of formation of cyanoprokaryote blooms in Clarrie Hall Dam. The detection of the A. circinalis (non saxitoxin-producing strain) in the riverine impoundment at Bray Park in 2007, at concentrations below the NHMRC alert levels, did cause some concern since this is the raw water uptake point for the treatment plant. Although this strain was not producing toxins, aesthetics, taste and odour issues became management concerns as the cell concentrations increased. The production of high CYN concentrations by a combined bloom of C. raciborskii and A.ovalisporum occurred in Cobaki Lake in the dry year of 2007. An increase in distribution of these toxin-producing blooms affects both the decisions and the cost of raw water treatment and recreational water management, especially in times of low rainfall in the Tweed Shire. Weather patterns can be unpredictable; especially in sub-tropical regions such as the Tweed Shire where storm and rain events are common regardless of the season and result in flushing of the system. Conversely, in periods of dry, settled weather patterns involving low rainfall, long retention times can result. These extended retention times, combined with reduced nutrient loads and stratification, encourage the growth of troublesome nostocalean cyanoprokarytotes. Management of water bodies during dry, settled weather patterns would therefore aim at effective control of both retention time and stratification of the water bodies. The unique situation in the Tweed Shire allows the riverine impoundment at Bray Park to be flushed by releasing water from Clarrie Hall Dam. This ability to flush the water across the weir when required has proven to be reasonably successful in the past with regard to Chapter 10. Summary and Conclusions 204 minimising algal blooms and maintaining water source quality. Increased population trends in the district have, however, meant that water supply is precious and the decision to release water from Clarrie Hall Dam in times of low rainfall and dropping dam levels is difficult. The data collected at Cobaki Lake provides delineation of the toxin profiles and specialised cell dynamics of different species of cyanoprokaryote species capable of producing potent toxins. These species can appear when conditions are conducive to their growth and distribution. Water management in the Tweed Shire should aim to prevent the development of similar conditions to those of Cobaki Lake in the main water supply areas of the catchment such as in the main storage facility (Clarrie Hall Dam) and the uptake point for water treatment (Tweed River at Bray Park). Similarily, prevention of similar conditions that have occurred in Cobaki Lake arising in decorative lakes in future development along the coastal fringe of the shire would be preferable. One of the key pressures on the Tweed system is that of population growth and sustainable development. Existing demographic data for Australia show that coastal cities are consistently experiencing higher growth levels than the rest of the mainland (BITRE (2011)). The BITRE (2011) report states that the average annual growth for coastal cities was 2.3% over the period 2001–2009 whilst metropolitan areas were 1.6% Understanding the dynamics of man-made decorative and recreational lakes such as Cobaki Lake will assist in the prevention of future public health issues, especially those involving high concentrations of stable dissolved cyanotoxins such as CYN and deoxy-CYN that are associated with marine or saline ground-water intrusions. Chapter 10. Summary and Conclusions 205 10.2 Summary of new knowledge and management implications 1. This research adds to the existing database on the water quality and phytoplankton assemblages of freshwater Australian systems including coastal, subtropical catchments. It involved monitoring of three different types of water bodies in the Tweed catchment (a storage dam, a riverine impoundment and a small decorative lake) over a two year period including both dry and wet seasons. This is the first substantial study of these water bodies in the Tweed Shire. 2. This study has contributed to the understanding of the hydrological status associated with man-made structures (dams/reservoirs, weirs and artificial lakes) and phytoplankton interactions involving toxin producing cyanoprokaryotes. The conditions in Cobaki Lake in 2007 were conducive to the growth of toxin- producing cyanoprokaryotes; and depth profiling of the toxin concentrations revealed the concentration of extracellular CYN at depth. 3. This research will contribute to the future management of raw water quality, storage and treatment in the Tweed shire. In particular, this research has explored the conditions that were conducive to the growth of toxin-producing cyanoprokaryote populations; future management strategies should be aimed at preventing or modifying the development of these conditions in water storages across the Tweed Shire. 4. The research findings at Cobaki Lake will assist in the design and management of future coastal development involving decorative and recreational lakes. The stratification that occurred in Cobaki Lake in 2007 involving a halocline with saline intrusion resulted in the growth of toxin-producing cyanoprokaryotes. These conditions prevented this lake from being used for the purposes that it was intended, such as for recreation and providing a source of extra water for vegetable gardens and external household use. Chapter 10. Summary and Conclusions 206 5. This study indicates the need to use cell concentration depth profiles as a key tool in monitoring and management of CYN-producing blooms, particularly those of C. raciborskii. Relying solely on visual inspection of water bodies and surface sampling could result in public health being compromised. It is likely that this situation is true for other sub-tropical sites. 6. This research demonstrates the need to understand the toxin profile before determining the off-take depth where C. raciborskii and A. ovalsiporum cell concentrations are concerned. Furthermore, a large amount of CYN may be extracellular and dissolved in the water column. This is not reflected in the cell count and for this reason, total toxin determination, including both intracellular and extracellular concentrations should be considered for health risk assessment. 7. This research has identified the ability of real-time PCR to quickly and easily identify potential toxin-producers so that they can be targeted and managed, while being mindful of the issues raised in this study regarding extracellular CYN at depth. 8. This study has revealed the presence of Limnothrix in the Tweed Shire, a species capable of producing a novel and dangerous water-soluble toxin (“Limnothrixin”). 10.3 Future Work This research also illustrated other areas of study that have yet to be addressed. Key amongst these are indicated below; 1. This study has revealed that a gap in knowledge exists with regard to why the toxins, CYN and deoxy-CYN are able to accumulate at depth away from the cyanoprokaryote cells which produced those toxins. If these dynamics can be understood the ability to manage and reduce these issues could be devised. Chapter 10. Summary and Conclusions 207 2. Associated with point 1 is the future collection and analysis of the sediment and hypolimnetic water which, coupled with corresponding physical data, could supply further information on how and why CYN and deoxy-CYN accumulate at depth. 3. There is a need to better understand the dynamics of CYN and deoxy-CYN, especially in hypolimnetic water. To this end, laboratory experiments could be performed to identify decomposition rates/factors with a view to generating ways of reducing deoxy-CYN in field environments (in the same way that destratification reduces cell counts). 4. Consideration and examination of the potential for groundwater intrusions and the characteristics of incoming water are necessary, since these may impact on the subsequent concentrations of cylindrospermopsins. The intrusion of saline water leads to greater differences in density of the layers of a water body and hence more stable stratification. The effect these intrusions have on CYN and deoxy-CYN accumulation may also contribute to understanding this problem. 5. Associated with point 4 is the need to understand more about CYN concentrations in the marine environment and its affect on modern sustainable development in coastal cities. 6. This research has shown that PCR is an excellent methodology, however it is unable to detect extracellular toxin in water bodies. Future research could indicate how PCR is able to predict furture toxin release and more importantly, potential concentrations if they can show a relationship that is measurable. 7. There is a need for wider comparison studies for sub-tropical environments and cooler environments where CYN-producers are starting to appear. This will expand the knowledge and database and assist in understanding the CYN depth profile dynamics in a variety of situations world-wide. Chapter 10. Summary and Conclusions 208 8. The data collection in the Tweed Shire catchment could be expanded to include additional tests and a variety of seasons. This will again expand the knowledge and data base and provide a greater base for comparison. 9. Limnothrix/Geitlerinema cell concentrations and accompanying toxin should be studied in greater detail in the Tweed Shire as well as nationally.” End [WSRPRG - 12.4.2019] Question 1 Has Tweed Shire Council considered the conclusions of the above report in their preparation of a Drought Management Strategy and has this report been previously presented for consideration by Council? Of interest, at our last meeting I mentioned that it had been reported that the Clarrie Hall Dam mixer was not operational. A council staff member replied that the unfixed mixer had not made any difference to algal control over the last season. Note; “Artificial mixing not only discourages cyanobacteria but can also address the release of iron, manganese and nutrients from the sediments, which occurs when reservoirs become stratified.” [Management Strategies for Cyanobacteria (Blue-Green Algae): A Guide for Water Utilities Research Report No 74, 2.6.3 Artificial destratification, Para.3, P. 52] Question 2 Please supply the outstanding items, as requested in my letter dated 19th March 2019 and email dated April 5 2019 10:18 AM Requested items outstanding are as follows: Algal cell counts and their Biovolume ratings required for the period 2002 to 2019 remains outstanding “On the 22nd February 2019, I requested by phone from Mr Hancock, details of any ‘Red Alert’ Blue Green algal events which may have occurred between 2002 to 2008 and 2015 to 2018 in the Bray Park Weir/Clarrie Hall Dam water storage system. As this information was not readily available from the records of Tweed Shire Council, I now request that you please provide this information, showing algal cell counts and their Biovolume ratings for the period 2002 to 2019 at Bray Park Weir water storage. (a) Please provide the council record, which shows details of the algal cell counts and Biovolume ratings sampled at Bray Park Weir water storage for the period 2002 to 2019? Outstanding request: The council document 'Develop Risk Based Water Quality Management Plan - [CNR-OC] Integrated Water Cycle Management (IWCM) Strategy Status Report. [Action 3 ]' reads “Council adopted the Drinking Water Quality Policy(Version1.0)”. “In December 2010, Water Futures P/L carried out an assessment of TSC’s compliance with ADWG including a gap analysis”. “Consequently TSC engaged Water Futures to address some of the high priority elements identified by the gap analysis. The Project is about 50% complete. The most critical element are practically complete and the remaining elements will be completed by Water Futures, Hunter Water Australia and TSC by the end of June 2010”. My Request (b) Council’s email of 4th April 2019 advises that the Report from Water Futures Report, which identifies high priority elements from their previous gap analysis assessment is now incorporated in the Blue-green Algal Management Standard Operating Procedure [SOP - Blue-green Algae Management / WHS Unit / Jan-19). • Please confirm that this is the case and also • Please forward the council’s Drinking Water Quality Policy document. Additional Request In respect of the information requested from the Laboratory Report 190388, Mr Paul Wright wrote on the 4th April 2019 and confirmed by phone, that the strain of Dolichospermum circinale sampled in the laboratory report 190388 was non-toxic; the same as previous Tweed blooms and that this strain has not been named. Request Although this non-toxic strain of Dolichospermum circinale identified in the laboratory test of 1st February 2019 has not been ‘named’, has this ‘non- toxin’ been allotted a number by researchers? Richard W Murray. From: Richard W Murray [mailto:rwmy125@tpg.com.au] Sent: Friday, April 5, 2019 10:18 AM To: Elizabeth Seidl Subject: Algal cell counts required for consideration by the Water Strategies Review Project Reference Group Importance: High Hello Elizabeth Please find attached my letter dated 3rd April 2019 seeking further information about Tweed Shire Council Laboratory Report 190388. In respect of the information requested from this Laboratory Report, Mr Paul Wright responded on the 4th April 2019, with the following email. Mr Wright confirmed by phone, that the non-toxic strain of Dolichospermum circinale found in the laboratory test of February 2019 and for previous Tweed blooms was ‘unnamed’. Thank you for the information requested for this laboratory report. The other information requested in my letters dated 19th March and 3rd April 2019 is about item 4 (as below), remains outstanding, and available from another area of council administration. Item 4. Algal cell counts and their Biovolume ratings required for the period 2002 to 2019 “On the 22nd February 2019, I requested by phone from Mr Hancock, details of any ‘Red Alert’ Blue Green algal events which may have occurred between 2002 to 2008 and 2015 to 2018 in the Bray Park Weir/Clarrie Hall Dam water storage system. As this information was not readily available from the records of Tweed Shire Council, I now request that you please provide this information, showing algal cell counts and their Biovolume ratings for the period 2002 to 2019”? This information is required for consideration by the Water Strategies Review Project Reference Group to understand future raw water quality at the Bray Park Weir water storage. Thank you for your consideration of this request. Yours sincerely Richard W Murray Previous correspondence From: Paul Wright [mailto:PaulW@tweed.nsw.gov.au] Sent: Thursday, April 4, 2019 12:04 PM To: rwmy125@tpg.com.au Cc: Anthony Burnham; Sally Hinton; Amanda Ind Subject: Clarification of Strains vs Species Hi Andrew, (Richard) Just a quick clarification in relation to your correspondence from the 3rd of April. A strain is a local/geographical population with a genetic variation within a species. Please see this site for an in depth definition: https://en.wikipedia.org/wiki/Strain_(biology) Thus for the potentially toxic species Dolichospermum circinale there may be dozens of different strains throughout NSW, each with slightly different characteristics including the capacity to produce Saxitoxin or not. As already mentioned, we have been lucky here in Tweed that we have had non-toxic strain(s) of this species. Hope this clarifies that matter for you. Kind regards Paul Wright PhD. Lab Coordinator Water and Wastewater p (07) 5569 3101 From: Elizabeth Seidl [mailto:ESeidl@tweed.nsw.gov.au] Sent: Thursday, April 4, 2019 10:32 AM To: Richard W Murray Cc: Brenda Hannigan; Robert Siebert; Marty Hancock Subject: RE: Request for the ‘Risk Based Water Quality Management Plan’ as developed by Water Futures, Hunter Australia and TSC (2011). Hi Richard Marty Hancock informs me that there were a number of interim reports but none were adopted by Council as a ‘Plan’. The content of these reports has been incorporated in the Drinking Water Management System document which I have already sent you. Please understand that It was a project that ran over several years with a number of iterations and work done by Water Futures and others at different times as required. It would be appreciated and more appropriate if you could raise your specific concerns and/or information request at the PRG meeting next Wednesday. We need to be clear about what information you are seeking. Regards Elizabeth Elizabeth Seidl BE Hons (Chemical) Engineer - Water Efficiency and Connections on Facebook Share 15.4.2019 Questions on Drought contingency and water supply emergency management measures and Water Quality. Following PRG meeting of the 10th April 2019, I wish to confirm that that the undermentioned document was handed to Elizabeth Seidl for consideration by the Water Strategies Review Project Reference Group when the group considers: The Hydrosphere option: ‘Drought contingency and water supply emergency management measures need to be further developed’ [Hydrosphere Six Year IWCM Review Background Paper Item 16 Para. 4/5, Paper P.37] The Hydrosphere Drought Management Strategy recommended inter alia: • Develop a Blue Green Algae Management Plan. • Install an additional mixer in the Clarrie Hall Dam to enhance the capacity, flexibility of the existing system and provide system redundancy. Council is reviewing the performance of the destratification system. The undermentioned research document was prepared by a member of the Tweed Shire Council Laboratory and was assisted by additional financial and in-kind support provided to the project by the Central Queensland University, Centre for Environmental Management, the Tweed Shire Council and the Tweed Laboratory Centre, as well as the assistance from staff past and present of the Tweed Shire Council Water Unit, the Tweed Laboratory Centre, the Bray Park Water Treatment Plant Research comparing three water bodies from the Tweed River catchment – July 2013 Phytoplankton Ecology of the Tweed River Catchment with reference to toxin-producing cyanoprokaryotes DOI: 10.13140/RG.2.1.4119.1920 Thesis for: Doctor of Philosophy, Advisor: Associate Professor Larelle Fabbro - July 2013 Sally Everson - Independent Researcher Abstract - [Summary] This research compared three water bodies from the Tweed River catchment, using a combination of field and laboratory studies. The study yielded new insights about the conditions that favour the growth of toxin-producing cyanoprokaryotes (blue-green algae). The species of interest included Cylindrospermopsis raciborskii and Aphanizomenon ovalisporum (now Chrysosporum ovalisporum) and the toxin Cylindrospermopsin (CYN). This information is important in managing risks for drinking and recreational water supplies in subtropical areas worldwide. https://www.researchgate.net/publication/304585873_Phytoplankton_Ecology_of_the_Tweed_River_Catchment_with_reference_to_toxin-producing_cyanoprokaryotes Abstract continued: “The management of human health risks in drinking water supplies is a global challenge, particularly in the context of urban population growth, increased water demands and climate change. Cyanoprokaryotes and their toxins may present a serious risk to the quality of drinking water supplies. Understanding the ecology of algal assemblages and their accompanying risks is therefore critically important for effective management of those water bodies that experience problematic cyanoprokaryote blooms.” “This project was conducted within the Tweed River catchment, a coastal subtropical area under pressure from population growth, ongoing development and climate change. The three study sites chosen in the catchment were: (1) a small artificial lake with a maximum depth of 19 m and covering an area of 2.5 hectares (Cobaki Lake); (2) a water storage facility with a maximum depth of 20 m, a destratification unit installed, and an area of 340 hectares (Clarrie Hall Dam); and (3) a flowing river with a maximum depth of 4 m (Tweed River at Bray Park). Water column dynamics, water chemistry and algal assemblages were investigated”. The conclusion of this thesis reads: “Chapter 10. Summary and Conclusions P., 203 The study showed a statistically significantly increased presence of cyanoprokaryotes in the dry warmer year, compared with the wet, cooler months of 2008. Changes in the speciation and toxicity patterns within the phytoplankton populations were also highlighted. The appearance of non saxitoxin-producing A. circinalis in Clarrie Hall Dam in the wet year did not result in a bloom, despite triggering the NHMRC high alert level for drinking water with a concentration greater than 6,500 cells mL-1. Increased rainfall resulted in reduced retention time with significant outflow of water and associated flushing of Clarrie Hall Dam. This flushing contributed to the lack of formation of cyanoprokaryote blooms in Clarrie Hall Dam. The detection of the A. circinalis (non saxitoxin-producing strain) in the riverine impoundment at Bray Park in 2007, at concentrations below the NHMRC alert levels, did cause some concern since this is the raw water uptake point for the treatment plant. Although this strain was not producing toxins, aesthetics, taste and odour issues became management concerns as the cell concentrations increased. The production of high CYN concentrations by a combined bloom of C. raciborskii and A.ovalisporum occurred in Cobaki Lake in the dry year of 2007. An increase in distribution of these toxin-producing blooms affects both the decisions and the cost of raw water treatment and recreational water management, especially in times of low rainfall in the Tweed Shire. Weather patterns can be unpredictable; especially in sub-tropical regions such as the Tweed Shire where storm and rain events are common regardless of the season and result in flushing of the system. Conversely, in periods of dry, settled weather patterns involving low rainfall, long retention times can result. These extended retention times, combined with reduced nutrient loads and stratification, encourage the growth of troublesome nostocalean cyanoprokarytotes. Management of water bodies during dry, settled weather patterns would therefore aim at effective control of both retention time and stratification of the water bodies. The unique situation in the Tweed Shire allows the riverine impoundment at Bray Park to be flushed by releasing water from Clarrie Hall Dam. This ability to flush the water across the weir when required has proven to be reasonably successful in the past with regard to Chapter 10. Summary and Conclusions 204 minimising algal blooms and maintaining water source quality. Increased population trends in the district have, however, meant that water supply is precious and the decision to release water from Clarrie Hall Dam in times of low rainfall and dropping dam levels is difficult. The data collected at Cobaki Lake provides delineation of the toxin profiles and specialised cell dynamics of different species of cyanoprokaryote species capable of producing potent toxins. These species can appear when conditions are conducive to their growth and distribution. Water management in the Tweed Shire should aim to prevent the development of similar conditions to those of Cobaki Lake in the main water supply areas of the catchment such as in the main storage facility (Clarrie Hall Dam) and the uptake point for water treatment (Tweed River at Bray Park). Similarily, prevention of similar conditions that have occurred in Cobaki Lake arising in decorative lakes in future development along the coastal fringe of the shire would be preferable. One of the key pressures on the Tweed system is that of population growth and sustainable development. Existing demographic data for Australia show that coastal cities are consistently experiencing higher growth levels than the rest of the mainland (BITRE (2011)). The BITRE (2011) report states that the average annual growth for coastal cities was 2.3% over the period 2001–2009 whilst metropolitan areas were 1.6% Understanding the dynamics of man-made decorative and recreational lakes such as Cobaki Lake will assist in the prevention of future public health issues, especially those involving high concentrations of stable dissolved cyanotoxins such as CYN and deoxy-CYN that are associated with marine or saline ground-water intrusions. Chapter 10. Summary and Conclusions 205 10.2 Summary of new knowledge and management implications 1. This research adds to the existing database on the water quality and phytoplankton assemblages of freshwater Australian systems including coastal, subtropical catchments. It involved monitoring of three different types of water bodies in the Tweed catchment (a storage dam, a riverine impoundment and a small decorative lake) over a two year period including both dry and wet seasons. This is the first substantial study of these water bodies in the Tweed Shire. 2. This study has contributed to the understanding of the hydrological status associated with man-made structures (dams/reservoirs, weirs and artificial lakes) and phytoplankton interactions involving toxin producing cyanoprokaryotes. The conditions in Cobaki Lake in 2007 were conducive to the growth of toxin- producing cyanoprokaryotes; and depth profiling of the toxin concentrations revealed the concentration of extracellular CYN at depth. 3. This research will contribute to the future management of raw water quality, storage and treatment in the Tweed shire. In particular, this research has explored the conditions that were conducive to the growth of toxin-producing cyanoprokaryote populations; future management strategies should be aimed at preventing or modifying the development of these conditions in water storages across the Tweed Shire. 4. The research findings at Cobaki Lake will assist in the design and management of future coastal development involving decorative and recreational lakes. The stratification that occurred in Cobaki Lake in 2007 involving a halocline with saline intrusion resulted in the growth of toxin-producing cyanoprokaryotes. These conditions prevented this lake from being used for the purposes that it was intended, such as for recreation and providing a source of extra water for vegetable gardens and external household use. Chapter 10. Summary and Conclusions 206 5. This study indicates the need to use cell concentration depth profiles as a key tool in monitoring and management of CYN-producing blooms, particularly those of C. raciborskii. Relying solely on visual inspection of water bodies and surface sampling could result in public health being compromised. It is likely that this situation is true for other sub-tropical sites. 6. This research demonstrates the need to understand the toxin profile before determining the off-take depth where C. raciborskii and A. ovalsiporum cell concentrations are concerned. Furthermore, a large amount of CYN may be extracellular and dissolved in the water column. This is not reflected in the cell count and for this reason, total toxin determination, including both intracellular and extracellular concentrations should be considered for health risk assessment. 7. This research has identified the ability of real-time PCR to quickly and easily identify potential toxin-producers so that they can be targeted and managed, while being mindful of the issues raised in this study regarding extracellular CYN at depth. 8. This study has revealed the presence of Limnothrix in the Tweed Shire, a species capable of producing a novel and dangerous water-soluble toxin (“Limnothrixin”). 10.3 Future Work This research also illustrated other areas of study that have yet to be addressed. Key amongst these are indicated below; 1. This study has revealed that a gap in knowledge exists with regard to why the toxins, CYN and deoxy-CYN are able to accumulate at depth away from the cyanoprokaryote cells which produced those toxins. If these dynamics can be understood the ability to manage and reduce these issues could be devised. Chapter 10. Summary and Conclusions 207 2. Associated with point 1 is the future collection and analysis of the sediment and hypolimnetic water which, coupled with corresponding physical data, could supply further information on how and why CYN and deoxy-CYN accumulate at depth. 3. There is a need to better understand the dynamics of CYN and deoxy-CYN, especially in hypolimnetic water. To this end, laboratory experiments could be performed to identify decomposition rates/factors with a view to generating ways of reducing deoxy-CYN in field environments (in the same way that destratification reduces cell counts). 4. Consideration and examination of the potential for groundwater intrusions and the characteristics of incoming water are necessary, since these may impact on the subsequent concentrations of cylindrospermopsins. The intrusion of saline water leads to greater differences in density of the layers of a water body and hence more stable stratification. The effect these intrusions have on CYN and deoxy-CYN accumulation may also contribute to understanding this problem. 5. Associated with point 4 is the need to understand more about CYN concentrations in the marine environment and its affect on modern sustainable development in coastal cities. 6. This research has shown that PCR is an excellent methodology, however it is unable to detect extracellular toxin in water bodies. Future research could indicate how PCR is able to predict furture toxin release and more importantly, potential concentrations if they can show a relationship that is measurable. 7. There is a need for wider comparison studies for sub-tropical environments and cooler environments where CYN-producers are starting to appear. This will expand the knowledge and database and assist in understanding the CYN depth profile dynamics in a variety of situations world-wide. Chapter 10. Summary and Conclusions 208 8. The data collection in the Tweed Shire catchment could be expanded to include additional tests and a variety of seasons. This will again expand the knowledge and data base and provide a greater base for comparison. 9. Limnothrix/Geitlerinema cell concentrations and accompanying toxin should be studied in greater detail in the Tweed Shire as well as nationally.” End [WSRPRG - 12.4.2019] Question 1 Has Tweed Shire Council considered the conclusions of the above report in their preparation of a Drought Management Strategy and has this report been previously presented for consideration by Council? Of interest, at our last meeting I mentioned that it had been reported that the Clarrie Hall Dam mixer was not operational. A council staff member replied that the unfixed mixer had not made any difference to algal control over the last season. Note; “Artificial mixing not only discourages cyanobacteria but can also address the release of iron, manganese and nutrients from the sediments, which occurs when reservoirs become stratified.” [Management Strategies for Cyanobacteria (Blue-Green Algae): A Guide for Water Utilities Research Report No 74, 2.6.3 Artificial destratification, Para.3, P. 52] Question 2 Please supply the outstanding items, as requested in my letter dated 19th March 2019 and email dated April 5 2019 10:18 AM Requested items outstanding are as follows: Algal cell counts and their Biovolume ratings required for the period 2002 to 2019 remains outstanding “On the 22nd February 2019, I requested by phone from Mr Hancock, details of any ‘Red Alert’ Blue Green algal events which may have occurred between 2002 to 2008 and 2015 to 2018 in the Bray Park Weir/Clarrie Hall Dam water storage system. As this information was not readily available from the records of Tweed Shire Council, I now request that you please provide this information, showing algal cell counts and their Biovolume ratings for the period 2002 to 2019 at Bray Park Weir water storage. (a) Please provide the council record, which shows details of the algal cell counts and Biovolume ratings sampled at Bray Park Weir water storage for the period 2002 to 2019? Outstanding request: The council document 'Develop Risk Based Water Quality Management Plan - [CNR-OC] Integrated Water Cycle Management (IWCM) Strategy Status Report. [Action 3 ]' reads “Council adopted the Drinking Water Quality Policy(Version1.0)”. “In December 2010, Water Futures P/L carried out an assessment of TSC’s compliance with ADWG including a gap analysis”. “Consequently TSC engaged Water Futures to address some of the high priority elements identified by the gap analysis. The Project is about 50% complete. The most critical element are practically complete and the remaining elements will be completed by Water Futures, Hunter Water Australia and TSC by the end of June 2010”. My Request (b) Council’s email of 4th April 2019 advises that the Report from Water Futures Report, which identifies high priority elements from their previous gap analysis assessment is now incorporated in the Blue-green Algal Management Standard Operating Procedure [SOP - Blue-green Algae Management / WHS Unit / Jan-19). • Please confirm that this is the case and also • Please forward the council’s Drinking Water Quality Policy document. Additional Request In respect of the information requested from the Laboratory Report 190388, Mr Paul Wright wrote on the 4th April 2019 and confirmed by phone, that the strain of Dolichospermum circinale sampled in the laboratory report 190388 was non-toxic; the same as previous Tweed blooms and that this strain has not been named. Request Although this non-toxic strain of Dolichospermum circinale identified in the laboratory test of 1st February 2019 has not been ‘named’, has this ‘non- toxin’ been allotted a number by researchers? Richard W Murray. From: Richard W Murray [mailto:rwmy125@tpg.com.au] Sent: Friday, April 5, 2019 10:18 AM To: Elizabeth Seidl Subject: Algal cell counts required for consideration by the Water Strategies Review Project Reference Group Importance: High Hello Elizabeth Please find attached my letter dated 3rd April 2019 seeking further information about Tweed Shire Council Laboratory Report 190388. In respect of the information requested from this Laboratory Report, Mr Paul Wright responded on the 4th April 2019, with the following email. Mr Wright confirmed by phone, that the non-toxic strain of Dolichospermum circinale found in the laboratory test of February 2019 and for previous Tweed blooms was ‘unnamed’. Thank you for the information requested for this laboratory report. The other information requested in my letters dated 19th March and 3rd April 2019 is about item 4 (as below), remains outstanding, and available from another area of council administration. Item 4. Algal cell counts and their Biovolume ratings required for the period 2002 to 2019 “On the 22nd February 2019, I requested by phone from Mr Hancock, details of any ‘Red Alert’ Blue Green algal events which may have occurred between 2002 to 2008 and 2015 to 2018 in the Bray Park Weir/Clarrie Hall Dam water storage system. As this information was not readily available from the records of Tweed Shire Council, I now request that you please provide this information, showing algal cell counts and their Biovolume ratings for the period 2002 to 2019”? This information is required for consideration by the Water Strategies Review Project Reference Group to understand future raw water quality at the Bray Park Weir water storage. Thank you for your consideration of this request. Yours sincerely Richard W Murray Previous correspondence From: Paul Wright [mailto:PaulW@tweed.nsw.gov.au] Sent: Thursday, April 4, 2019 12:04 PM To: rwmy125@tpg.com.au Cc: Anthony Burnham; Sally Hinton; Amanda Ind Subject: Clarification of Strains vs Species Hi Andrew, (Richard) Just a quick clarification in relation to your correspondence from the 3rd of April. A strain is a local/geographical population with a genetic variation within a species. Please see this site for an in depth definition: https://en.wikipedia.org/wiki/Strain_(biology) Thus for the potentially toxic species Dolichospermum circinale there may be dozens of different strains throughout NSW, each with slightly different characteristics including the capacity to produce Saxitoxin or not. As already mentioned, we have been lucky here in Tweed that we have had non-toxic strain(s) of this species. Hope this clarifies that matter for you. Kind regards Paul Wright PhD. Lab Coordinator Water and Wastewater p (07) 5569 3101 From: Elizabeth Seidl [mailto:ESeidl@tweed.nsw.gov.au] Sent: Thursday, April 4, 2019 10:32 AM To: Richard W Murray Cc: Brenda Hannigan; Robert Siebert; Marty Hancock Subject: RE: Request for the ‘Risk Based Water Quality Management Plan’ as developed by Water Futures, Hunter Australia and TSC (2011). Hi Richard Marty Hancock informs me that there were a number of interim reports but none were adopted by Council as a ‘Plan’. The content of these reports has been incorporated in the Drinking Water Management System document which I have already sent you. Please understand that It was a project that ran over several years with a number of iterations and work done by Water Futures and others at different times as required. It would be appreciated and more appropriate if you could raise your specific concerns and/or information request at the PRG meeting next Wednesday. We need to be clear about what information you are seeking. Regards Elizabeth Elizabeth Seidl BE Hons (Chemical) Engineer - Water Efficiency and Connections on Twitter Share 15.4.2019 Questions on Drought contingency and water supply emergency management measures and Water Quality. Following PRG meeting of the 10th April 2019, I wish to confirm that that the undermentioned document was handed to Elizabeth Seidl for consideration by the Water Strategies Review Project Reference Group when the group considers: The Hydrosphere option: ‘Drought contingency and water supply emergency management measures need to be further developed’ [Hydrosphere Six Year IWCM Review Background Paper Item 16 Para. 4/5, Paper P.37] The Hydrosphere Drought Management Strategy recommended inter alia: • Develop a Blue Green Algae Management Plan. • Install an additional mixer in the Clarrie Hall Dam to enhance the capacity, flexibility of the existing system and provide system redundancy. Council is reviewing the performance of the destratification system. The undermentioned research document was prepared by a member of the Tweed Shire Council Laboratory and was assisted by additional financial and in-kind support provided to the project by the Central Queensland University, Centre for Environmental Management, the Tweed Shire Council and the Tweed Laboratory Centre, as well as the assistance from staff past and present of the Tweed Shire Council Water Unit, the Tweed Laboratory Centre, the Bray Park Water Treatment Plant Research comparing three water bodies from the Tweed River catchment – July 2013 Phytoplankton Ecology of the Tweed River Catchment with reference to toxin-producing cyanoprokaryotes DOI: 10.13140/RG.2.1.4119.1920 Thesis for: Doctor of Philosophy, Advisor: Associate Professor Larelle Fabbro - July 2013 Sally Everson - Independent Researcher Abstract - [Summary] This research compared three water bodies from the Tweed River catchment, using a combination of field and laboratory studies. The study yielded new insights about the conditions that favour the growth of toxin-producing cyanoprokaryotes (blue-green algae). The species of interest included Cylindrospermopsis raciborskii and Aphanizomenon ovalisporum (now Chrysosporum ovalisporum) and the toxin Cylindrospermopsin (CYN). This information is important in managing risks for drinking and recreational water supplies in subtropical areas worldwide. https://www.researchgate.net/publication/304585873_Phytoplankton_Ecology_of_the_Tweed_River_Catchment_with_reference_to_toxin-producing_cyanoprokaryotes Abstract continued: “The management of human health risks in drinking water supplies is a global challenge, particularly in the context of urban population growth, increased water demands and climate change. Cyanoprokaryotes and their toxins may present a serious risk to the quality of drinking water supplies. Understanding the ecology of algal assemblages and their accompanying risks is therefore critically important for effective management of those water bodies that experience problematic cyanoprokaryote blooms.” “This project was conducted within the Tweed River catchment, a coastal subtropical area under pressure from population growth, ongoing development and climate change. The three study sites chosen in the catchment were: (1) a small artificial lake with a maximum depth of 19 m and covering an area of 2.5 hectares (Cobaki Lake); (2) a water storage facility with a maximum depth of 20 m, a destratification unit installed, and an area of 340 hectares (Clarrie Hall Dam); and (3) a flowing river with a maximum depth of 4 m (Tweed River at Bray Park). Water column dynamics, water chemistry and algal assemblages were investigated”. The conclusion of this thesis reads: “Chapter 10. Summary and Conclusions P., 203 The study showed a statistically significantly increased presence of cyanoprokaryotes in the dry warmer year, compared with the wet, cooler months of 2008. Changes in the speciation and toxicity patterns within the phytoplankton populations were also highlighted. The appearance of non saxitoxin-producing A. circinalis in Clarrie Hall Dam in the wet year did not result in a bloom, despite triggering the NHMRC high alert level for drinking water with a concentration greater than 6,500 cells mL-1. Increased rainfall resulted in reduced retention time with significant outflow of water and associated flushing of Clarrie Hall Dam. This flushing contributed to the lack of formation of cyanoprokaryote blooms in Clarrie Hall Dam. The detection of the A. circinalis (non saxitoxin-producing strain) in the riverine impoundment at Bray Park in 2007, at concentrations below the NHMRC alert levels, did cause some concern since this is the raw water uptake point for the treatment plant. Although this strain was not producing toxins, aesthetics, taste and odour issues became management concerns as the cell concentrations increased. The production of high CYN concentrations by a combined bloom of C. raciborskii and A.ovalisporum occurred in Cobaki Lake in the dry year of 2007. An increase in distribution of these toxin-producing blooms affects both the decisions and the cost of raw water treatment and recreational water management, especially in times of low rainfall in the Tweed Shire. Weather patterns can be unpredictable; especially in sub-tropical regions such as the Tweed Shire where storm and rain events are common regardless of the season and result in flushing of the system. Conversely, in periods of dry, settled weather patterns involving low rainfall, long retention times can result. These extended retention times, combined with reduced nutrient loads and stratification, encourage the growth of troublesome nostocalean cyanoprokarytotes. Management of water bodies during dry, settled weather patterns would therefore aim at effective control of both retention time and stratification of the water bodies. The unique situation in the Tweed Shire allows the riverine impoundment at Bray Park to be flushed by releasing water from Clarrie Hall Dam. This ability to flush the water across the weir when required has proven to be reasonably successful in the past with regard to Chapter 10. Summary and Conclusions 204 minimising algal blooms and maintaining water source quality. Increased population trends in the district have, however, meant that water supply is precious and the decision to release water from Clarrie Hall Dam in times of low rainfall and dropping dam levels is difficult. The data collected at Cobaki Lake provides delineation of the toxin profiles and specialised cell dynamics of different species of cyanoprokaryote species capable of producing potent toxins. These species can appear when conditions are conducive to their growth and distribution. Water management in the Tweed Shire should aim to prevent the development of similar conditions to those of Cobaki Lake in the main water supply areas of the catchment such as in the main storage facility (Clarrie Hall Dam) and the uptake point for water treatment (Tweed River at Bray Park). Similarily, prevention of similar conditions that have occurred in Cobaki Lake arising in decorative lakes in future development along the coastal fringe of the shire would be preferable. One of the key pressures on the Tweed system is that of population growth and sustainable development. Existing demographic data for Australia show that coastal cities are consistently experiencing higher growth levels than the rest of the mainland (BITRE (2011)). The BITRE (2011) report states that the average annual growth for coastal cities was 2.3% over the period 2001–2009 whilst metropolitan areas were 1.6% Understanding the dynamics of man-made decorative and recreational lakes such as Cobaki Lake will assist in the prevention of future public health issues, especially those involving high concentrations of stable dissolved cyanotoxins such as CYN and deoxy-CYN that are associated with marine or saline ground-water intrusions. Chapter 10. Summary and Conclusions 205 10.2 Summary of new knowledge and management implications 1. This research adds to the existing database on the water quality and phytoplankton assemblages of freshwater Australian systems including coastal, subtropical catchments. It involved monitoring of three different types of water bodies in the Tweed catchment (a storage dam, a riverine impoundment and a small decorative lake) over a two year period including both dry and wet seasons. This is the first substantial study of these water bodies in the Tweed Shire. 2. This study has contributed to the understanding of the hydrological status associated with man-made structures (dams/reservoirs, weirs and artificial lakes) and phytoplankton interactions involving toxin producing cyanoprokaryotes. The conditions in Cobaki Lake in 2007 were conducive to the growth of toxin- producing cyanoprokaryotes; and depth profiling of the toxin concentrations revealed the concentration of extracellular CYN at depth. 3. This research will contribute to the future management of raw water quality, storage and treatment in the Tweed shire. In particular, this research has explored the conditions that were conducive to the growth of toxin-producing cyanoprokaryote populations; future management strategies should be aimed at preventing or modifying the development of these conditions in water storages across the Tweed Shire. 4. The research findings at Cobaki Lake will assist in the design and management of future coastal development involving decorative and recreational lakes. The stratification that occurred in Cobaki Lake in 2007 involving a halocline with saline intrusion resulted in the growth of toxin-producing cyanoprokaryotes. These conditions prevented this lake from being used for the purposes that it was intended, such as for recreation and providing a source of extra water for vegetable gardens and external household use. Chapter 10. Summary and Conclusions 206 5. This study indicates the need to use cell concentration depth profiles as a key tool in monitoring and management of CYN-producing blooms, particularly those of C. raciborskii. Relying solely on visual inspection of water bodies and surface sampling could result in public health being compromised. It is likely that this situation is true for other sub-tropical sites. 6. This research demonstrates the need to understand the toxin profile before determining the off-take depth where C. raciborskii and A. ovalsiporum cell concentrations are concerned. Furthermore, a large amount of CYN may be extracellular and dissolved in the water column. This is not reflected in the cell count and for this reason, total toxin determination, including both intracellular and extracellular concentrations should be considered for health risk assessment. 7. This research has identified the ability of real-time PCR to quickly and easily identify potential toxin-producers so that they can be targeted and managed, while being mindful of the issues raised in this study regarding extracellular CYN at depth. 8. This study has revealed the presence of Limnothrix in the Tweed Shire, a species capable of producing a novel and dangerous water-soluble toxin (“Limnothrixin”). 10.3 Future Work This research also illustrated other areas of study that have yet to be addressed. Key amongst these are indicated below; 1. This study has revealed that a gap in knowledge exists with regard to why the toxins, CYN and deoxy-CYN are able to accumulate at depth away from the cyanoprokaryote cells which produced those toxins. If these dynamics can be understood the ability to manage and reduce these issues could be devised. Chapter 10. Summary and Conclusions 207 2. Associated with point 1 is the future collection and analysis of the sediment and hypolimnetic water which, coupled with corresponding physical data, could supply further information on how and why CYN and deoxy-CYN accumulate at depth. 3. There is a need to better understand the dynamics of CYN and deoxy-CYN, especially in hypolimnetic water. To this end, laboratory experiments could be performed to identify decomposition rates/factors with a view to generating ways of reducing deoxy-CYN in field environments (in the same way that destratification reduces cell counts). 4. Consideration and examination of the potential for groundwater intrusions and the characteristics of incoming water are necessary, since these may impact on the subsequent concentrations of cylindrospermopsins. The intrusion of saline water leads to greater differences in density of the layers of a water body and hence more stable stratification. The effect these intrusions have on CYN and deoxy-CYN accumulation may also contribute to understanding this problem. 5. Associated with point 4 is the need to understand more about CYN concentrations in the marine environment and its affect on modern sustainable development in coastal cities. 6. This research has shown that PCR is an excellent methodology, however it is unable to detect extracellular toxin in water bodies. Future research could indicate how PCR is able to predict furture toxin release and more importantly, potential concentrations if they can show a relationship that is measurable. 7. There is a need for wider comparison studies for sub-tropical environments and cooler environments where CYN-producers are starting to appear. This will expand the knowledge and database and assist in understanding the CYN depth profile dynamics in a variety of situations world-wide. Chapter 10. Summary and Conclusions 208 8. The data collection in the Tweed Shire catchment could be expanded to include additional tests and a variety of seasons. This will again expand the knowledge and data base and provide a greater base for comparison. 9. Limnothrix/Geitlerinema cell concentrations and accompanying toxin should be studied in greater detail in the Tweed Shire as well as nationally.” End [WSRPRG - 12.4.2019] Question 1 Has Tweed Shire Council considered the conclusions of the above report in their preparation of a Drought Management Strategy and has this report been previously presented for consideration by Council? Of interest, at our last meeting I mentioned that it had been reported that the Clarrie Hall Dam mixer was not operational. A council staff member replied that the unfixed mixer had not made any difference to algal control over the last season. Note; “Artificial mixing not only discourages cyanobacteria but can also address the release of iron, manganese and nutrients from the sediments, which occurs when reservoirs become stratified.” [Management Strategies for Cyanobacteria (Blue-Green Algae): A Guide for Water Utilities Research Report No 74, 2.6.3 Artificial destratification, Para.3, P. 52] Question 2 Please supply the outstanding items, as requested in my letter dated 19th March 2019 and email dated April 5 2019 10:18 AM Requested items outstanding are as follows: Algal cell counts and their Biovolume ratings required for the period 2002 to 2019 remains outstanding “On the 22nd February 2019, I requested by phone from Mr Hancock, details of any ‘Red Alert’ Blue Green algal events which may have occurred between 2002 to 2008 and 2015 to 2018 in the Bray Park Weir/Clarrie Hall Dam water storage system. As this information was not readily available from the records of Tweed Shire Council, I now request that you please provide this information, showing algal cell counts and their Biovolume ratings for the period 2002 to 2019 at Bray Park Weir water storage. (a) Please provide the council record, which shows details of the algal cell counts and Biovolume ratings sampled at Bray Park Weir water storage for the period 2002 to 2019? Outstanding request: The council document 'Develop Risk Based Water Quality Management Plan - [CNR-OC] Integrated Water Cycle Management (IWCM) Strategy Status Report. [Action 3 ]' reads “Council adopted the Drinking Water Quality Policy(Version1.0)”. “In December 2010, Water Futures P/L carried out an assessment of TSC’s compliance with ADWG including a gap analysis”. “Consequently TSC engaged Water Futures to address some of the high priority elements identified by the gap analysis. The Project is about 50% complete. The most critical element are practically complete and the remaining elements will be completed by Water Futures, Hunter Water Australia and TSC by the end of June 2010”. My Request (b) Council’s email of 4th April 2019 advises that the Report from Water Futures Report, which identifies high priority elements from their previous gap analysis assessment is now incorporated in the Blue-green Algal Management Standard Operating Procedure [SOP - Blue-green Algae Management / WHS Unit / Jan-19). • Please confirm that this is the case and also • Please forward the council’s Drinking Water Quality Policy document. Additional Request In respect of the information requested from the Laboratory Report 190388, Mr Paul Wright wrote on the 4th April 2019 and confirmed by phone, that the strain of Dolichospermum circinale sampled in the laboratory report 190388 was non-toxic; the same as previous Tweed blooms and that this strain has not been named. Request Although this non-toxic strain of Dolichospermum circinale identified in the laboratory test of 1st February 2019 has not been ‘named’, has this ‘non- toxin’ been allotted a number by researchers? Richard W Murray. From: Richard W Murray [mailto:rwmy125@tpg.com.au] Sent: Friday, April 5, 2019 10:18 AM To: Elizabeth Seidl Subject: Algal cell counts required for consideration by the Water Strategies Review Project Reference Group Importance: High Hello Elizabeth Please find attached my letter dated 3rd April 2019 seeking further information about Tweed Shire Council Laboratory Report 190388. In respect of the information requested from this Laboratory Report, Mr Paul Wright responded on the 4th April 2019, with the following email. Mr Wright confirmed by phone, that the non-toxic strain of Dolichospermum circinale found in the laboratory test of February 2019 and for previous Tweed blooms was ‘unnamed’. Thank you for the information requested for this laboratory report. The other information requested in my letters dated 19th March and 3rd April 2019 is about item 4 (as below), remains outstanding, and available from another area of council administration. Item 4. Algal cell counts and their Biovolume ratings required for the period 2002 to 2019 “On the 22nd February 2019, I requested by phone from Mr Hancock, details of any ‘Red Alert’ Blue Green algal events which may have occurred between 2002 to 2008 and 2015 to 2018 in the Bray Park Weir/Clarrie Hall Dam water storage system. As this information was not readily available from the records of Tweed Shire Council, I now request that you please provide this information, showing algal cell counts and their Biovolume ratings for the period 2002 to 2019”? This information is required for consideration by the Water Strategies Review Project Reference Group to understand future raw water quality at the Bray Park Weir water storage. Thank you for your consideration of this request. Yours sincerely Richard W Murray Previous correspondence From: Paul Wright [mailto:PaulW@tweed.nsw.gov.au] Sent: Thursday, April 4, 2019 12:04 PM To: rwmy125@tpg.com.au Cc: Anthony Burnham; Sally Hinton; Amanda Ind Subject: Clarification of Strains vs Species Hi Andrew, (Richard) Just a quick clarification in relation to your correspondence from the 3rd of April. A strain is a local/geographical population with a genetic variation within a species. Please see this site for an in depth definition: https://en.wikipedia.org/wiki/Strain_(biology) Thus for the potentially toxic species Dolichospermum circinale there may be dozens of different strains throughout NSW, each with slightly different characteristics including the capacity to produce Saxitoxin or not. As already mentioned, we have been lucky here in Tweed that we have had non-toxic strain(s) of this species. Hope this clarifies that matter for you. Kind regards Paul Wright PhD. Lab Coordinator Water and Wastewater p (07) 5569 3101 From: Elizabeth Seidl [mailto:ESeidl@tweed.nsw.gov.au] Sent: Thursday, April 4, 2019 10:32 AM To: Richard W Murray Cc: Brenda Hannigan; Robert Siebert; Marty Hancock Subject: RE: Request for the ‘Risk Based Water Quality Management Plan’ as developed by Water Futures, Hunter Australia and TSC (2011). Hi Richard Marty Hancock informs me that there were a number of interim reports but none were adopted by Council as a ‘Plan’. The content of these reports has been incorporated in the Drinking Water Management System document which I have already sent you. Please understand that It was a project that ran over several years with a number of iterations and work done by Water Futures and others at different times as required. It would be appreciated and more appropriate if you could raise your specific concerns and/or information request at the PRG meeting next Wednesday. We need to be clear about what information you are seeking. Regards Elizabeth Elizabeth Seidl BE Hons (Chemical) Engineer - Water Efficiency and Connections on Linkedin Email 15.4.2019 Questions on Drought contingency and water supply emergency management measures and Water Quality. Following PRG meeting of the 10th April 2019, I wish to confirm that that the undermentioned document was handed to Elizabeth Seidl for consideration by the Water Strategies Review Project Reference Group when the group considers: The Hydrosphere option: ‘Drought contingency and water supply emergency management measures need to be further developed’ [Hydrosphere Six Year IWCM Review Background Paper Item 16 Para. 4/5, Paper P.37] The Hydrosphere Drought Management Strategy recommended inter alia: • Develop a Blue Green Algae Management Plan. • Install an additional mixer in the Clarrie Hall Dam to enhance the capacity, flexibility of the existing system and provide system redundancy. Council is reviewing the performance of the destratification system. The undermentioned research document was prepared by a member of the Tweed Shire Council Laboratory and was assisted by additional financial and in-kind support provided to the project by the Central Queensland University, Centre for Environmental Management, the Tweed Shire Council and the Tweed Laboratory Centre, as well as the assistance from staff past and present of the Tweed Shire Council Water Unit, the Tweed Laboratory Centre, the Bray Park Water Treatment Plant Research comparing three water bodies from the Tweed River catchment – July 2013 Phytoplankton Ecology of the Tweed River Catchment with reference to toxin-producing cyanoprokaryotes DOI: 10.13140/RG.2.1.4119.1920 Thesis for: Doctor of Philosophy, Advisor: Associate Professor Larelle Fabbro - July 2013 Sally Everson - Independent Researcher Abstract - [Summary] This research compared three water bodies from the Tweed River catchment, using a combination of field and laboratory studies. The study yielded new insights about the conditions that favour the growth of toxin-producing cyanoprokaryotes (blue-green algae). The species of interest included Cylindrospermopsis raciborskii and Aphanizomenon ovalisporum (now Chrysosporum ovalisporum) and the toxin Cylindrospermopsin (CYN). This information is important in managing risks for drinking and recreational water supplies in subtropical areas worldwide. https://www.researchgate.net/publication/304585873_Phytoplankton_Ecology_of_the_Tweed_River_Catchment_with_reference_to_toxin-producing_cyanoprokaryotes Abstract continued: “The management of human health risks in drinking water supplies is a global challenge, particularly in the context of urban population growth, increased water demands and climate change. Cyanoprokaryotes and their toxins may present a serious risk to the quality of drinking water supplies. Understanding the ecology of algal assemblages and their accompanying risks is therefore critically important for effective management of those water bodies that experience problematic cyanoprokaryote blooms.” “This project was conducted within the Tweed River catchment, a coastal subtropical area under pressure from population growth, ongoing development and climate change. The three study sites chosen in the catchment were: (1) a small artificial lake with a maximum depth of 19 m and covering an area of 2.5 hectares (Cobaki Lake); (2) a water storage facility with a maximum depth of 20 m, a destratification unit installed, and an area of 340 hectares (Clarrie Hall Dam); and (3) a flowing river with a maximum depth of 4 m (Tweed River at Bray Park). Water column dynamics, water chemistry and algal assemblages were investigated”. The conclusion of this thesis reads: “Chapter 10. Summary and Conclusions P., 203 The study showed a statistically significantly increased presence of cyanoprokaryotes in the dry warmer year, compared with the wet, cooler months of 2008. Changes in the speciation and toxicity patterns within the phytoplankton populations were also highlighted. The appearance of non saxitoxin-producing A. circinalis in Clarrie Hall Dam in the wet year did not result in a bloom, despite triggering the NHMRC high alert level for drinking water with a concentration greater than 6,500 cells mL-1. Increased rainfall resulted in reduced retention time with significant outflow of water and associated flushing of Clarrie Hall Dam. This flushing contributed to the lack of formation of cyanoprokaryote blooms in Clarrie Hall Dam. The detection of the A. circinalis (non saxitoxin-producing strain) in the riverine impoundment at Bray Park in 2007, at concentrations below the NHMRC alert levels, did cause some concern since this is the raw water uptake point for the treatment plant. Although this strain was not producing toxins, aesthetics, taste and odour issues became management concerns as the cell concentrations increased. The production of high CYN concentrations by a combined bloom of C. raciborskii and A.ovalisporum occurred in Cobaki Lake in the dry year of 2007. An increase in distribution of these toxin-producing blooms affects both the decisions and the cost of raw water treatment and recreational water management, especially in times of low rainfall in the Tweed Shire. Weather patterns can be unpredictable; especially in sub-tropical regions such as the Tweed Shire where storm and rain events are common regardless of the season and result in flushing of the system. Conversely, in periods of dry, settled weather patterns involving low rainfall, long retention times can result. These extended retention times, combined with reduced nutrient loads and stratification, encourage the growth of troublesome nostocalean cyanoprokarytotes. Management of water bodies during dry, settled weather patterns would therefore aim at effective control of both retention time and stratification of the water bodies. The unique situation in the Tweed Shire allows the riverine impoundment at Bray Park to be flushed by releasing water from Clarrie Hall Dam. This ability to flush the water across the weir when required has proven to be reasonably successful in the past with regard to Chapter 10. Summary and Conclusions 204 minimising algal blooms and maintaining water source quality. Increased population trends in the district have, however, meant that water supply is precious and the decision to release water from Clarrie Hall Dam in times of low rainfall and dropping dam levels is difficult. The data collected at Cobaki Lake provides delineation of the toxin profiles and specialised cell dynamics of different species of cyanoprokaryote species capable of producing potent toxins. These species can appear when conditions are conducive to their growth and distribution. Water management in the Tweed Shire should aim to prevent the development of similar conditions to those of Cobaki Lake in the main water supply areas of the catchment such as in the main storage facility (Clarrie Hall Dam) and the uptake point for water treatment (Tweed River at Bray Park). Similarily, prevention of similar conditions that have occurred in Cobaki Lake arising in decorative lakes in future development along the coastal fringe of the shire would be preferable. One of the key pressures on the Tweed system is that of population growth and sustainable development. Existing demographic data for Australia show that coastal cities are consistently experiencing higher growth levels than the rest of the mainland (BITRE (2011)). The BITRE (2011) report states that the average annual growth for coastal cities was 2.3% over the period 2001–2009 whilst metropolitan areas were 1.6% Understanding the dynamics of man-made decorative and recreational lakes such as Cobaki Lake will assist in the prevention of future public health issues, especially those involving high concentrations of stable dissolved cyanotoxins such as CYN and deoxy-CYN that are associated with marine or saline ground-water intrusions. Chapter 10. Summary and Conclusions 205 10.2 Summary of new knowledge and management implications 1. This research adds to the existing database on the water quality and phytoplankton assemblages of freshwater Australian systems including coastal, subtropical catchments. It involved monitoring of three different types of water bodies in the Tweed catchment (a storage dam, a riverine impoundment and a small decorative lake) over a two year period including both dry and wet seasons. This is the first substantial study of these water bodies in the Tweed Shire. 2. This study has contributed to the understanding of the hydrological status associated with man-made structures (dams/reservoirs, weirs and artificial lakes) and phytoplankton interactions involving toxin producing cyanoprokaryotes. The conditions in Cobaki Lake in 2007 were conducive to the growth of toxin- producing cyanoprokaryotes; and depth profiling of the toxin concentrations revealed the concentration of extracellular CYN at depth. 3. This research will contribute to the future management of raw water quality, storage and treatment in the Tweed shire. In particular, this research has explored the conditions that were conducive to the growth of toxin-producing cyanoprokaryote populations; future management strategies should be aimed at preventing or modifying the development of these conditions in water storages across the Tweed Shire. 4. The research findings at Cobaki Lake will assist in the design and management of future coastal development involving decorative and recreational lakes. The stratification that occurred in Cobaki Lake in 2007 involving a halocline with saline intrusion resulted in the growth of toxin-producing cyanoprokaryotes. These conditions prevented this lake from being used for the purposes that it was intended, such as for recreation and providing a source of extra water for vegetable gardens and external household use. Chapter 10. Summary and Conclusions 206 5. This study indicates the need to use cell concentration depth profiles as a key tool in monitoring and management of CYN-producing blooms, particularly those of C. raciborskii. Relying solely on visual inspection of water bodies and surface sampling could result in public health being compromised. It is likely that this situation is true for other sub-tropical sites. 6. This research demonstrates the need to understand the toxin profile before determining the off-take depth where C. raciborskii and A. ovalsiporum cell concentrations are concerned. Furthermore, a large amount of CYN may be extracellular and dissolved in the water column. This is not reflected in the cell count and for this reason, total toxin determination, including both intracellular and extracellular concentrations should be considered for health risk assessment. 7. This research has identified the ability of real-time PCR to quickly and easily identify potential toxin-producers so that they can be targeted and managed, while being mindful of the issues raised in this study regarding extracellular CYN at depth. 8. This study has revealed the presence of Limnothrix in the Tweed Shire, a species capable of producing a novel and dangerous water-soluble toxin (“Limnothrixin”). 10.3 Future Work This research also illustrated other areas of study that have yet to be addressed. Key amongst these are indicated below; 1. This study has revealed that a gap in knowledge exists with regard to why the toxins, CYN and deoxy-CYN are able to accumulate at depth away from the cyanoprokaryote cells which produced those toxins. If these dynamics can be understood the ability to manage and reduce these issues could be devised. Chapter 10. Summary and Conclusions 207 2. Associated with point 1 is the future collection and analysis of the sediment and hypolimnetic water which, coupled with corresponding physical data, could supply further information on how and why CYN and deoxy-CYN accumulate at depth. 3. There is a need to better understand the dynamics of CYN and deoxy-CYN, especially in hypolimnetic water. To this end, laboratory experiments could be performed to identify decomposition rates/factors with a view to generating ways of reducing deoxy-CYN in field environments (in the same way that destratification reduces cell counts). 4. Consideration and examination of the potential for groundwater intrusions and the characteristics of incoming water are necessary, since these may impact on the subsequent concentrations of cylindrospermopsins. The intrusion of saline water leads to greater differences in density of the layers of a water body and hence more stable stratification. The effect these intrusions have on CYN and deoxy-CYN accumulation may also contribute to understanding this problem. 5. Associated with point 4 is the need to understand more about CYN concentrations in the marine environment and its affect on modern sustainable development in coastal cities. 6. This research has shown that PCR is an excellent methodology, however it is unable to detect extracellular toxin in water bodies. Future research could indicate how PCR is able to predict furture toxin release and more importantly, potential concentrations if they can show a relationship that is measurable. 7. There is a need for wider comparison studies for sub-tropical environments and cooler environments where CYN-producers are starting to appear. This will expand the knowledge and database and assist in understanding the CYN depth profile dynamics in a variety of situations world-wide. Chapter 10. Summary and Conclusions 208 8. The data collection in the Tweed Shire catchment could be expanded to include additional tests and a variety of seasons. This will again expand the knowledge and data base and provide a greater base for comparison. 9. Limnothrix/Geitlerinema cell concentrations and accompanying toxin should be studied in greater detail in the Tweed Shire as well as nationally.” End [WSRPRG - 12.4.2019] Question 1 Has Tweed Shire Council considered the conclusions of the above report in their preparation of a Drought Management Strategy and has this report been previously presented for consideration by Council? Of interest, at our last meeting I mentioned that it had been reported that the Clarrie Hall Dam mixer was not operational. A council staff member replied that the unfixed mixer had not made any difference to algal control over the last season. Note; “Artificial mixing not only discourages cyanobacteria but can also address the release of iron, manganese and nutrients from the sediments, which occurs when reservoirs become stratified.” [Management Strategies for Cyanobacteria (Blue-Green Algae): A Guide for Water Utilities Research Report No 74, 2.6.3 Artificial destratification, Para.3, P. 52] Question 2 Please supply the outstanding items, as requested in my letter dated 19th March 2019 and email dated April 5 2019 10:18 AM Requested items outstanding are as follows: Algal cell counts and their Biovolume ratings required for the period 2002 to 2019 remains outstanding “On the 22nd February 2019, I requested by phone from Mr Hancock, details of any ‘Red Alert’ Blue Green algal events which may have occurred between 2002 to 2008 and 2015 to 2018 in the Bray Park Weir/Clarrie Hall Dam water storage system. As this information was not readily available from the records of Tweed Shire Council, I now request that you please provide this information, showing algal cell counts and their Biovolume ratings for the period 2002 to 2019 at Bray Park Weir water storage. (a) Please provide the council record, which shows details of the algal cell counts and Biovolume ratings sampled at Bray Park Weir water storage for the period 2002 to 2019? Outstanding request: The council document 'Develop Risk Based Water Quality Management Plan - [CNR-OC] Integrated Water Cycle Management (IWCM) Strategy Status Report. [Action 3 ]' reads “Council adopted the Drinking Water Quality Policy(Version1.0)”. “In December 2010, Water Futures P/L carried out an assessment of TSC’s compliance with ADWG including a gap analysis”. “Consequently TSC engaged Water Futures to address some of the high priority elements identified by the gap analysis. The Project is about 50% complete. The most critical element are practically complete and the remaining elements will be completed by Water Futures, Hunter Water Australia and TSC by the end of June 2010”. My Request (b) Council’s email of 4th April 2019 advises that the Report from Water Futures Report, which identifies high priority elements from their previous gap analysis assessment is now incorporated in the Blue-green Algal Management Standard Operating Procedure [SOP - Blue-green Algae Management / WHS Unit / Jan-19). • Please confirm that this is the case and also • Please forward the council’s Drinking Water Quality Policy document. Additional Request In respect of the information requested from the Laboratory Report 190388, Mr Paul Wright wrote on the 4th April 2019 and confirmed by phone, that the strain of Dolichospermum circinale sampled in the laboratory report 190388 was non-toxic; the same as previous Tweed blooms and that this strain has not been named. Request Although this non-toxic strain of Dolichospermum circinale identified in the laboratory test of 1st February 2019 has not been ‘named’, has this ‘non- toxin’ been allotted a number by researchers? Richard W Murray. From: Richard W Murray [mailto:rwmy125@tpg.com.au] Sent: Friday, April 5, 2019 10:18 AM To: Elizabeth Seidl Subject: Algal cell counts required for consideration by the Water Strategies Review Project Reference Group Importance: High Hello Elizabeth Please find attached my letter dated 3rd April 2019 seeking further information about Tweed Shire Council Laboratory Report 190388. In respect of the information requested from this Laboratory Report, Mr Paul Wright responded on the 4th April 2019, with the following email. Mr Wright confirmed by phone, that the non-toxic strain of Dolichospermum circinale found in the laboratory test of February 2019 and for previous Tweed blooms was ‘unnamed’. Thank you for the information requested for this laboratory report. The other information requested in my letters dated 19th March and 3rd April 2019 is about item 4 (as below), remains outstanding, and available from another area of council administration. Item 4. Algal cell counts and their Biovolume ratings required for the period 2002 to 2019 “On the 22nd February 2019, I requested by phone from Mr Hancock, details of any ‘Red Alert’ Blue Green algal events which may have occurred between 2002 to 2008 and 2015 to 2018 in the Bray Park Weir/Clarrie Hall Dam water storage system. As this information was not readily available from the records of Tweed Shire Council, I now request that you please provide this information, showing algal cell counts and their Biovolume ratings for the period 2002 to 2019”? This information is required for consideration by the Water Strategies Review Project Reference Group to understand future raw water quality at the Bray Park Weir water storage. Thank you for your consideration of this request. Yours sincerely Richard W Murray Previous correspondence From: Paul Wright [mailto:PaulW@tweed.nsw.gov.au] Sent: Thursday, April 4, 2019 12:04 PM To: rwmy125@tpg.com.au Cc: Anthony Burnham; Sally Hinton; Amanda Ind Subject: Clarification of Strains vs Species Hi Andrew, (Richard) Just a quick clarification in relation to your correspondence from the 3rd of April. A strain is a local/geographical population with a genetic variation within a species. Please see this site for an in depth definition: https://en.wikipedia.org/wiki/Strain_(biology) Thus for the potentially toxic species Dolichospermum circinale there may be dozens of different strains throughout NSW, each with slightly different characteristics including the capacity to produce Saxitoxin or not. As already mentioned, we have been lucky here in Tweed that we have had non-toxic strain(s) of this species. Hope this clarifies that matter for you. Kind regards Paul Wright PhD. Lab Coordinator Water and Wastewater p (07) 5569 3101 From: Elizabeth Seidl [mailto:ESeidl@tweed.nsw.gov.au] Sent: Thursday, April 4, 2019 10:32 AM To: Richard W Murray Cc: Brenda Hannigan; Robert Siebert; Marty Hancock Subject: RE: Request for the ‘Risk Based Water Quality Management Plan’ as developed by Water Futures, Hunter Australia and TSC (2011). Hi Richard Marty Hancock informs me that there were a number of interim reports but none were adopted by Council as a ‘Plan’. The content of these reports has been incorporated in the Drinking Water Management System document which I have already sent you. Please understand that It was a project that ran over several years with a number of iterations and work done by Water Futures and others at different times as required. It would be appreciated and more appropriate if you could raise your specific concerns and/or information request at the PRG meeting next Wednesday. We need to be clear about what information you are seeking. Regards Elizabeth Elizabeth Seidl BE Hons (Chemical) Engineer - Water Efficiency and Connections link
15.4.2019 Questions on Drought contingency and water supply emergency management measures and Water Quality. Following PRG meeting of the 10th April 2019, I wish to confirm that that the undermentioned document was handed to Elizabeth Seidl for consideration by the Water Strategies Review Project Reference Group when the group considers: The Hydrosphere option: ‘Drought contingency and water supply emergency management measures need to be further developed’ [Hydrosphere Six Year IWCM Review Background Paper Item 16 Para. 4/5, Paper P.37] The Hydrosphere Drought Management Strategy recommended inter alia: • Develop a Blue Green Algae Management Plan. • Install an additional mixer in the Clarrie Hall Dam to enhance the capacity, flexibility of the existing system and provide system redundancy. Council is reviewing the performance of the destratification system. The undermentioned research document was prepared by a member of the Tweed Shire Council Laboratory and was assisted by additional financial and in-kind support provided to the project by the Central Queensland University, Centre for Environmental Management, the Tweed Shire Council and the Tweed Laboratory Centre, as well as the assistance from staff past and present of the Tweed Shire Council Water Unit, the Tweed Laboratory Centre, the Bray Park Water Treatment Plant Research comparing three water bodies from the Tweed River catchment – July 2013 Phytoplankton Ecology of the Tweed River Catchment with reference to toxin-producing cyanoprokaryotes DOI: 10.13140/RG.2.1.4119.1920 Thesis for: Doctor of Philosophy, Advisor: Associate Professor Larelle Fabbro - July 2013 Sally Everson - Independent Researcher Abstract - [Summary] This research compared three water bodies from the Tweed River catchment, using a combination of field and laboratory studies. The study yielded new insights about the conditions that favour the growth of toxin-producing cyanoprokaryotes (blue-green algae). The species of interest included Cylindrospermopsis raciborskii and Aphanizomenon ovalisporum (now Chrysosporum ovalisporum) and the toxin Cylindrospermopsin (CYN). This information is important in managing risks for drinking and recreational water supplies in subtropical areas worldwide. https://www.researchgate.net/publication/304585873_Phytoplankton_Ecology_of_the_Tweed_River_Catchment_with_reference_to_toxin-producing_cyanoprokaryotes Abstract continued: “The management of human health risks in drinking water supplies is a global challenge, particularly in the context of urban population growth, increased water demands and climate change. Cyanoprokaryotes and their toxins may present a serious risk to the quality of drinking water supplies. Understanding the ecology of algal assemblages and their accompanying risks is therefore critically important for effective management of those water bodies that experience problematic cyanoprokaryote blooms.” “This project was conducted within the Tweed River catchment, a coastal subtropical area under pressure from population growth, ongoing development and climate change. The three study sites chosen in the catchment were: (1) a small artificial lake with a maximum depth of 19 m and covering an area of 2.5 hectares (Cobaki Lake); (2) a water storage facility with a maximum depth of 20 m, a destratification unit installed, and an area of 340 hectares (Clarrie Hall Dam); and (3) a flowing river with a maximum depth of 4 m (Tweed River at Bray Park). Water column dynamics, water chemistry and algal assemblages were investigated”. The conclusion of this thesis reads: “Chapter 10. Summary and Conclusions P., 203 The study showed a statistically significantly increased presence of cyanoprokaryotes in the dry warmer year, compared with the wet, cooler months of 2008. Changes in the speciation and toxicity patterns within the phytoplankton populations were also highlighted. The appearance of non saxitoxin-producing A. circinalis in Clarrie Hall Dam in the wet year did not result in a bloom, despite triggering the NHMRC high alert level for drinking water with a concentration greater than 6,500 cells mL-1. Increased rainfall resulted in reduced retention time with significant outflow of water and associated flushing of Clarrie Hall Dam. This flushing contributed to the lack of formation of cyanoprokaryote blooms in Clarrie Hall Dam. The detection of the A. circinalis (non saxitoxin-producing strain) in the riverine impoundment at Bray Park in 2007, at concentrations below the NHMRC alert levels, did cause some concern since this is the raw water uptake point for the treatment plant. Although this strain was not producing toxins, aesthetics, taste and odour issues became management concerns as the cell concentrations increased. The production of high CYN concentrations by a combined bloom of C. raciborskii and A.ovalisporum occurred in Cobaki Lake in the dry year of 2007. An increase in distribution of these toxin-producing blooms affects both the decisions and the cost of raw water treatment and recreational water management, especially in times of low rainfall in the Tweed Shire. Weather patterns can be unpredictable; especially in sub-tropical regions such as the Tweed Shire where storm and rain events are common regardless of the season and result in flushing of the system. Conversely, in periods of dry, settled weather patterns involving low rainfall, long retention times can result. These extended retention times, combined with reduced nutrient loads and stratification, encourage the growth of troublesome nostocalean cyanoprokarytotes. Management of water bodies during dry, settled weather patterns would therefore aim at effective control of both retention time and stratification of the water bodies. The unique situation in the Tweed Shire allows the riverine impoundment at Bray Park to be flushed by releasing water from Clarrie Hall Dam. This ability to flush the water across the weir when required has proven to be reasonably successful in the past with regard to Chapter 10. Summary and Conclusions 204 minimising algal blooms and maintaining water source quality. Increased population trends in the district have, however, meant that water supply is precious and the decision to release water from Clarrie Hall Dam in times of low rainfall and dropping dam levels is difficult. The data collected at Cobaki Lake provides delineation of the toxin profiles and specialised cell dynamics of different species of cyanoprokaryote species capable of producing potent toxins. These species can appear when conditions are conducive to their growth and distribution. Water management in the Tweed Shire should aim to prevent the development of similar conditions to those of Cobaki Lake in the main water supply areas of the catchment such as in the main storage facility (Clarrie Hall Dam) and the uptake point for water treatment (Tweed River at Bray Park). Similarily, prevention of similar conditions that have occurred in Cobaki Lake arising in decorative lakes in future development along the coastal fringe of the shire would be preferable. One of the key pressures on the Tweed system is that of population growth and sustainable development. Existing demographic data for Australia show that coastal cities are consistently experiencing higher growth levels than the rest of the mainland (BITRE (2011)). The BITRE (2011) report states that the average annual growth for coastal cities was 2.3% over the period 2001–2009 whilst metropolitan areas were 1.6% Understanding the dynamics of man-made decorative and recreational lakes such as Cobaki Lake will assist in the prevention of future public health issues, especially those involving high concentrations of stable dissolved cyanotoxins such as CYN and deoxy-CYN that are associated with marine or saline ground-water intrusions. Chapter 10. Summary and Conclusions 205 10.2 Summary of new knowledge and management implications 1. This research adds to the existing database on the water quality and phytoplankton assemblages of freshwater Australian systems including coastal, subtropical catchments. It involved monitoring of three different types of water bodies in the Tweed catchment (a storage dam, a riverine impoundment and a small decorative lake) over a two year period including both dry and wet seasons. This is the first substantial study of these water bodies in the Tweed Shire. 2. This study has contributed to the understanding of the hydrological status associated with man-made structures (dams/reservoirs, weirs and artificial lakes) and phytoplankton interactions involving toxin producing cyanoprokaryotes. The conditions in Cobaki Lake in 2007 were conducive to the growth of toxin- producing cyanoprokaryotes; and depth profiling of the toxin concentrations revealed the concentration of extracellular CYN at depth. 3. This research will contribute to the future management of raw water quality, storage and treatment in the Tweed shire. In particular, this research has explored the conditions that were conducive to the growth of toxin-producing cyanoprokaryote populations; future management strategies should be aimed at preventing or modifying the development of these conditions in water storages across the Tweed Shire. 4. The research findings at Cobaki Lake will assist in the design and management of future coastal development involving decorative and recreational lakes. The stratification that occurred in Cobaki Lake in 2007 involving a halocline with saline intrusion resulted in the growth of toxin-producing cyanoprokaryotes. These conditions prevented this lake from being used for the purposes that it was intended, such as for recreation and providing a source of extra water for vegetable gardens and external household use. Chapter 10. Summary and Conclusions 206 5. This study indicates the need to use cell concentration depth profiles as a key tool in monitoring and management of CYN-producing blooms, particularly those of C. raciborskii. Relying solely on visual inspection of water bodies and surface sampling could result in public health being compromised. It is likely that this situation is true for other sub-tropical sites. 6. This research demonstrates the need to understand the toxin profile before determining the off-take depth where C. raciborskii and A. ovalsiporum cell concentrations are concerned. Furthermore, a large amount of CYN may be extracellular and dissolved in the water column. This is not reflected in the cell count and for this reason, total toxin determination, including both intracellular and extracellular concentrations should be considered for health risk assessment. 7. This research has identified the ability of real-time PCR to quickly and easily identify potential toxin-producers so that they can be targeted and managed, while being mindful of the issues raised in this study regarding extracellular CYN at depth. 8. This study has revealed the presence of Limnothrix in the Tweed Shire, a species capable of producing a novel and dangerous water-soluble toxin (“Limnothrixin”). 10.3 Future Work This research also illustrated other areas of study that have yet to be addressed. Key amongst these are indicated below; 1. This study has revealed that a gap in knowledge exists with regard to why the toxins, CYN and deoxy-CYN are able to accumulate at depth away from the cyanoprokaryote cells which produced those toxins. If these dynamics can be understood the ability to manage and reduce these issues could be devised. Chapter 10. Summary and Conclusions 207 2. Associated with point 1 is the future collection and analysis of the sediment and hypolimnetic water which, coupled with corresponding physical data, could supply further information on how and why CYN and deoxy-CYN accumulate at depth. 3. There is a need to better understand the dynamics of CYN and deoxy-CYN, especially in hypolimnetic water. To this end, laboratory experiments could be performed to identify decomposition rates/factors with a view to generating ways of reducing deoxy-CYN in field environments (in the same way that destratification reduces cell counts). 4. Consideration and examination of the potential for groundwater intrusions and the characteristics of incoming water are necessary, since these may impact on the subsequent concentrations of cylindrospermopsins. The intrusion of saline water leads to greater differences in density of the layers of a water body and hence more stable stratification. The effect these intrusions have on CYN and deoxy-CYN accumulation may also contribute to understanding this problem. 5. Associated with point 4 is the need to understand more about CYN concentrations in the marine environment and its affect on modern sustainable development in coastal cities. 6. This research has shown that PCR is an excellent methodology, however it is unable to detect extracellular toxin in water bodies. Future research could indicate how PCR is able to predict furture toxin release and more importantly, potential concentrations if they can show a relationship that is measurable. 7. There is a need for wider comparison studies for sub-tropical environments and cooler environments where CYN-producers are starting to appear. This will expand the knowledge and database and assist in understanding the CYN depth profile dynamics in a variety of situations world-wide. Chapter 10. Summary and Conclusions 208 8. The data collection in the Tweed Shire catchment could be expanded to include additional tests and a variety of seasons. This will again expand the knowledge and data base and provide a greater base for comparison. 9. Limnothrix/Geitlerinema cell concentrations and accompanying toxin should be studied in greater detail in the Tweed Shire as well as nationally.” End [WSRPRG - 12.4.2019] Question 1 Has Tweed Shire Council considered the conclusions of the above report in their preparation of a Drought Management Strategy and has this report been previously presented for consideration by Council? Of interest, at our last meeting I mentioned that it had been reported that the Clarrie Hall Dam mixer was not operational. A council staff member replied that the unfixed mixer had not made any difference to algal control over the last season. Note; “Artificial mixing not only discourages cyanobacteria but can also address the release of iron, manganese and nutrients from the sediments, which occurs when reservoirs become stratified.” [Management Strategies for Cyanobacteria (Blue-Green Algae): A Guide for Water Utilities Research Report No 74, 2.6.3 Artificial destratification, Para.3, P. 52] Question 2 Please supply the outstanding items, as requested in my letter dated 19th March 2019 and email dated April 5 2019 10:18 AM Requested items outstanding are as follows: Algal cell counts and their Biovolume ratings required for the period 2002 to 2019 remains outstanding “On the 22nd February 2019, I requested by phone from Mr Hancock, details of any ‘Red Alert’ Blue Green algal events which may have occurred between 2002 to 2008 and 2015 to 2018 in the Bray Park Weir/Clarrie Hall Dam water storage system. As this information was not readily available from the records of Tweed Shire Council, I now request that you please provide this information, showing algal cell counts and their Biovolume ratings for the period 2002 to 2019 at Bray Park Weir water storage. (a) Please provide the council record, which shows details of the algal cell counts and Biovolume ratings sampled at Bray Park Weir water storage for the period 2002 to 2019? Outstanding request: The council document 'Develop Risk Based Water Quality Management Plan - [CNR-OC] Integrated Water Cycle Management (IWCM) Strategy Status Report. [Action 3 ]' reads “Council adopted the Drinking Water Quality Policy(Version1.0)”. “In December 2010, Water Futures P/L carried out an assessment of TSC’s compliance with ADWG including a gap analysis”. “Consequently TSC engaged Water Futures to address some of the high priority elements identified by the gap analysis. The Project is about 50% complete. The most critical element are practically complete and the remaining elements will be completed by Water Futures, Hunter Water Australia and TSC by the end of June 2010”. My Request (b) Council’s email of 4th April 2019 advises that the Report from Water Futures Report, which identifies high priority elements from their previous gap analysis assessment is now incorporated in the Blue-green Algal Management Standard Operating Procedure [SOP - Blue-green Algae Management / WHS Unit / Jan-19). • Please confirm that this is the case and also • Please forward the council’s Drinking Water Quality Policy document. Additional Request In respect of the information requested from the Laboratory Report 190388, Mr Paul Wright wrote on the 4th April 2019 and confirmed by phone, that the strain of Dolichospermum circinale sampled in the laboratory report 190388 was non-toxic; the same as previous Tweed blooms and that this strain has not been named. Request Although this non-toxic strain of Dolichospermum circinale identified in the laboratory test of 1st February 2019 has not been ‘named’, has this ‘non- toxin’ been allotted a number by researchers? Richard W Murray. From: Richard W Murray [mailto:rwmy125@tpg.com.au] Sent: Friday, April 5, 2019 10:18 AM To: Elizabeth Seidl Subject: Algal cell counts required for consideration by the Water Strategies Review Project Reference Group Importance: High Hello Elizabeth Please find attached my letter dated 3rd April 2019 seeking further information about Tweed Shire Council Laboratory Report 190388. In respect of the information requested from this Laboratory Report, Mr Paul Wright responded on the 4th April 2019, with the following email. Mr Wright confirmed by phone, that the non-toxic strain of Dolichospermum circinale found in the laboratory test of February 2019 and for previous Tweed blooms was ‘unnamed’. Thank you for the information requested for this laboratory report. The other information requested in my letters dated 19th March and 3rd April 2019 is about item 4 (as below), remains outstanding, and available from another area of council administration. Item 4. Algal cell counts and their Biovolume ratings required for the period 2002 to 2019 “On the 22nd February 2019, I requested by phone from Mr Hancock, details of any ‘Red Alert’ Blue Green algal events which may have occurred between 2002 to 2008 and 2015 to 2018 in the Bray Park Weir/Clarrie Hall Dam water storage system. As this information was not readily available from the records of Tweed Shire Council, I now request that you please provide this information, showing algal cell counts and their Biovolume ratings for the period 2002 to 2019”? This information is required for consideration by the Water Strategies Review Project Reference Group to understand future raw water quality at the Bray Park Weir water storage. Thank you for your consideration of this request. Yours sincerely Richard W Murray Previous correspondence From: Paul Wright [mailto:PaulW@tweed.nsw.gov.au] Sent: Thursday, April 4, 2019 12:04 PM To: rwmy125@tpg.com.au Cc: Anthony Burnham; Sally Hinton; Amanda Ind Subject: Clarification of Strains vs Species Hi Andrew, (Richard) Just a quick clarification in relation to your correspondence from the 3rd of April. A strain is a local/geographical population with a genetic variation within a species. Please see this site for an in depth definition: https://en.wikipedia.org/wiki/Strain_(biology) Thus for the potentially toxic species Dolichospermum circinale there may be dozens of different strains throughout NSW, each with slightly different characteristics including the capacity to produce Saxitoxin or not. As already mentioned, we have been lucky here in Tweed that we have had non-toxic strain(s) of this species. Hope this clarifies that matter for you. Kind regards Paul Wright PhD. Lab Coordinator Water and Wastewater p (07) 5569 3101 From: Elizabeth Seidl [mailto:ESeidl@tweed.nsw.gov.au] Sent: Thursday, April 4, 2019 10:32 AM To: Richard W Murray Cc: Brenda Hannigan; Robert Siebert; Marty Hancock Subject: RE: Request for the ‘Risk Based Water Quality Management Plan’ as developed by Water Futures, Hunter Australia and TSC (2011). Hi Richard Marty Hancock informs me that there were a number of interim reports but none were adopted by Council as a ‘Plan’. The content of these reports has been incorporated in the Drinking Water Management System document which I have already sent you. Please understand that It was a project that ran over several years with a number of iterations and work done by Water Futures and others at different times as required. It would be appreciated and more appropriate if you could raise your specific concerns and/or information request at the PRG meeting next Wednesday. We need to be clear about what information you are seeking. Regards Elizabeth Elizabeth Seidl BE Hons (Chemical) Engineer - Water Efficiency and Connections
Richard Warner Murray asked over 5 years agoPlease see the documents in the folder Blue-Green Algae in the Documents Library on this page.
Page last updated: 10 May 2021, 01:49 PM
Document Library
Key Dates
-
30 November 2020
-
02 November 2020