Coal seam gas waters - their geochemical signature and potential environmental implications

Coal Seam Gas (CSG) is a form of natural gas (mainly methane) sorbed in underground coal beds. To mine this gas, wells are drilled directly into an underground coal seam and groundwater (CSG water) is pumped out to the surface. This lowers the downhole piezometric pressure and enables gas desporption from the coal matrix. In the United States, this gas has been extracted commercially since the 1980s. The economic success of US CSG projects has inspired exploration and development in Australia and New Zealand. In Australia, Queensland’s Bowen and Surat basins have been the subject of increased CSG development over the last decade. CSG growth in other Australian basins has not matured to the same level but exploration and development are taking place at an accelerated pace in the Sydney Basin (Illawarra and the Hunter Valley, NSW) and in the Gunnedah Basin. Similarly, CSG exploration in New Zealand has focused in the Waikato region (Maramarua and Huntly), in the West Coast region (Buller, Reefton, and Greymouth), and in Southland (Kaitangata, Mataura, and Ohai). Figure 1 shows a Shcoeller diagram with CSG samples from selected basins in Australia, New Zealand, and the USA. CSG water from all of these basins exhibit the same geochemical signature – low calcium, low magnesium, high bicarbonate, low sulphate and, sometimes, high chloride. This water quality is a direct result of specific biological and geological processes that have taken part in the formation of CSG. In general, these processes include the weathering of rocks (carbonates, dolomite, and halite), cation exchange with clays (responsible for enhanced sodium and depleted calcium and magnesium), and biogenic processes (accounting for the presence of high bicarbonate concentrations). The salinity of CSG waters tends to be brackish (TDS < 30000 mg/l) with a fairly neutral pH. These particular characteristics need to be taken into consideration when assessing water management and disposal alternatives. Environmental issues associated with CSG water disposal have been prominent in developed basins such as the Powder River Basin (PRB) in the United States. When disposed on the land or used for irrigation, water having a high dissolved salts content may reduce water availability to crops thus affecting crop yield. In addition, the high sodium, low calcium and low magnesium concentrations increase the potential to disperse soils and significantly reduce the water infiltration rate. Therefore, CSG waters need to be properly characterised, treated, and disposed to safeguard the environment without compromising other natural resources.

Influence of Rainfall and Catchment Characteristics on Urban Stormwater Quality

The accuracy and reliability of urban stormwater quality modelling outcomes are important for stormwater management decision making. The commonly adopted approach where only a limited number of factors are used to predict urban stormwater quality may not adequately represent the complexity of the quality response to a rainfall event or site-to-site differences to support efficient treatment design. This paper discusses an investigation into the influence of rainfall and catchment characteristics on urban stormwater quality in order to investigate the potential areas for errors in current stormwater quality modelling practices. It was found that the influence of rainfall characteristics on pollutant wash-off is step-wise based on specific thresholds. This means that a modelling approach where the wash-off process is predicted as a continuous function of rainfall intensity and duration is not appropriate. Additionally, other than conventional catchment characteristics, namely, land use and impervious surface fraction, other catchment characteristics such as impervious area layout, urban form and site specific characteristics have an important influence on both, pollutant build-up and wash-off processes. Finally, the use of solids as a surrogate to estimate other pollutant species was found to be inappropriate. Individually considering build-up and wash-off processes for each pollutant species should be the preferred option.

Nitrous oxide emissions from irrigated wheat in Australia : impact of irrigation management

Background and Aims: Irrigation management affects soil water dynamics as well as the soil microbial carbon and nitrogen turnover and potentially the biosphere-atmosphere exchange of greenhouse gasses (GHG). We present a study on the effect of three irrigation treatments on the emissions of nitrous oxide (N2O) from irrigated wheat on black vertisols in South-Eastern Queensland, Australia. Methods: Soil N2O fluxes from wheat were monitored over one season with a fully automated system that measured emissions on a sub-daily basis. Measurements were taken from 3 subplots for each treatment within a randomized split-plot design. Results: Highest N2O emissions occurred after rainfall or irrigation and the amount of irrigation water applied was found to influence the magnitude of these “emission pulses”. Daily N2O emissions varied from -0.74 to 20.46 g N2O-N ha-1 day-1 resulting in seasonal losses ranging from 0.43 to 0.75 kg N2O N ha-1 season -1 for the different irrigation treatments. Emission factors (EF = proportion of N fertilizer emitted as N2O) over the wheat cropping season, uncorrected for background emissions, ranged from 0.2 to 0.4% of total N applied for the different treatments. Highest seasonal N2O emissions were observed in the treatment with the highest irrigation intensity; however, the N2O intensity (N2O emission per crop yield) was highest in the treatment with the lowest irrigation intensity. Conclusions: Our data suggest that timing and amount of irrigation can effectively be used to reduce N2O losses from irrigated agricultural systems; however, in order to develop sustainable mitigation strategies the N2O intensity of a cropping system is an important concept that needs to be taken into account.

A catchment modelling approach integrating surface and groundwater processes, land use and distribution of nutrients : Elimbah Creek, southeast Queensland

As the world’s population is growing, so is the demand for agricultural products. However, natural nitrogen (N) fixation and phosphorus (P) availability cannot sustain the rising agricultural production, thus, the application of N and P fertilisers as additional nutrient sources is common. It is those anthropogenic activities that can contribute high amounts of organic and inorganic nutrients to both surface and groundwaters resulting in degradation of water quality and a possible reduction of aquatic life. In addition, runoff and sewage from urban and residential areas can contain high amounts of inorganic and organic nutrients which may also affect water quality. For example, blooms of the cyanobacterium Lyngbya majuscula along the coastline of southeast Queensland are an indicator of at least short term decreases of water quality. Although Australian catchments, including those with intensive forms of land use, show in general a low export of nutrients compared to North American and European catchments, certain land use practices may still have a detrimental effect on the coastal environment. Numerous studies are reported on nutrient cycling and associated processes on a catchment scale in the Northern Hemisphere. Comparable studies in Australia, in particular in subtropical regions are, however, limited and there is a paucity in the data, in particular for inorganic and organic forms of nitrogen and phosphorus; these nutrients are important limiting factors in surface waters to promote algal blooms. Therefore, the monitoring of N and P and understanding the sources and pathways of these nutrients within a catchment is important in coastal zone management. Although Australia is the driest continent, in subtropical regions such as southeast Queensland, rainfall patterns have a significant effect on runoff and thus the nutrient cycle at a catchment scale. Increasingly, these rainfall patterns are becoming variable. The monitoring of these climatic conditions and the hydrological response of agricultural catchments is therefore also important to reduce the anthropogenic effects on surface and groundwater quality. This study consists of an integrated hydrological–hydrochemical approach that assesses N and P in an environment with multiple land uses. The main aim is to determine the nutrient cycle within a representative coastal catchment in southeast Queensland, the Elimbah Creek catchment. In particular, the investigation confirms the influence associated with forestry and agriculture on N and P forms, sources, distribution and fate in the surface and groundwaters of this subtropical setting. In addition, the study determines whether N and P are subject to transport into the adjacent estuary and thus into the marine environment; also considered is the effect of local topography, soils and geology on N and P sources and distribution. The thesis is structured on four components individually reported. The first paper determines the controls of catchment settings and processes on stream water, riverbank sediment, and shallow groundwater N and P concentrations, in particular during the extended dry conditions that were encountered during the study. Temporal and spatial factors such as seasonal changes, soil character, land use and catchment morphology are considered as well as their effect on controls over distributions of N and P in surface waters and associated groundwater. A total number of 30 surface and 13 shallow groundwater sampling sites were established throughout the catchment to represent dominant soil types and the land use upstream of each sampling location. Sampling comprises five rounds and was conducted over one year between October 2008 and November 2009. Surface water and groundwater samples were analysed for all major dissolved inorganic forms of N and for total N. Phosphorus was determined in the form of dissolved reactive P (predominantly orthophosphate) and total P. In addition, extracts of stream bank sediments and soil grab samples were analysed for these N and P species. Findings show that major storm events, in particular after long periods of drought conditions, are the driving force of N cycling. This is expressed by higher inorganic N concentrations in the agricultural subcatchment compared to the forested subcatchment. Nitrate N is the dominant inorganic form of N in both the surface and groundwaters and values are significantly higher in the groundwaters. Concentrations in the surface water range from 0.03 to 0.34 mg N L..1; organic N concentrations are considerably higher (average range: 0.33 to 0.85 mg N L..1), in particular in the forested subcatchment. Average NO3-N in the groundwater has a range of 0.39 to 2.08 mg N L..1, and organic N averages between 0.07 and 0.3 mg N L..1. The stream bank sediments are dominated by organic N (range: 0.53 to 0.65 mg N L..1), and the dominant inorganic form of N is NH4-N with values ranging between 0.38 and 0.41 mg N L..1. Topography and soils, however, were not to have a significant effect on N and P concentrations in waters. Detectable phosphorus in the surface and groundwaters of the catchment is limited to several locations typically in the proximity of areas with intensive animal use; in soil and sediments, P is negligible. In the second paper, the stable isotopes of N (14N/15N) and H2O (16O/18O and 2H/H) in surface and groundwaters are used to identify sources of dissolved inorganic and organic N in these waters, and to determine their pathways within the catchment; specific emphasis is placed on the relation of forestry and agriculture. Forestry is predominantly concentrated in the northern subcatchment (Beerburrum Creek) while agriculture is mainly found in the southern subcatchment (Six Mile Creek). Results show that agriculture (horticulture, crops, grazing) is the main source of inorganic N in the surface waters of the agricultural subcatchment, and their isotopic signature shows a close link to evaporation processes that may occur during water storage in farm dams that are used for irrigation. Groundwaters are subject to denitrification processes that may result in reduced dissolved inorganic N concentrations. Soil organic matter delivers most of the inorganic N to the surface water in the forested subcatchment. Here, precipitation and subsequently runoff is the main source of the surface waters. Groundwater in this area is affected by agricultural processes. The findings also show that the catchment can attenuate the effects of anthropogenic land use on surface water quality. Riparian strips of natural remnant vegetation, commonly 50 to 100 m in width, act as buffer zones along the drainage lines in the catchment and remove inorganic N from the soil water before it enters the creek. These riparian buffer zones are common in most agricultural catchments of southeast Queensland and are indicated to reduce the impact of agriculture on stream water quality and subsequently on the estuary and marine environments. This reduction is expressed by a significant decrease in DIN concentrations from 1.6 mg N L..1 to 0.09 mg N L..1, and a decrease in the �15N signatures from upstream surface water locations downstream to the outlet of the agricultural subcatchment. Further testing is, however, necessary to confirm these processes. Most importantly, the amount of N that is transported to the adjacent estuary is shown to be negligible. The third and fourth components of the thesis use a hydrological catchment model approach to determine the water balance of the Elimbah Creek catchment. The model is then used to simulate the effects of land use on the water balance and nutrient loads of the study area. The tool that is used is the internationally widely applied Soil and Water Assessment Tool (SWAT). Knowledge about the water cycle of a catchment is imperative in nutrient studies as processes such as rainfall, surface runoff, soil infiltration and routing of water through the drainage system are the driving forces of the catchment nutrient cycle. Long-term information about discharge volumes of the creeks and rivers do, however, not exist for a number of agricultural catchments in southeast Queensland, and such information is necessary to calibrate and validate numerical models. Therefore, a two-step modelling approach was used to calibrate and validate parameters values from a near-by gauged reference catchment as starting values for the ungauged Elimbah Creek catchment. Transposing monthly calibrated and validated parameter values from the reference catchment to the ungauged catchment significantly improved model performance showing that the hydrological model of the catchment of interest is a strong predictor of the water water balance. The model efficiency coefficient EF shows that 94% of the simulated discharge matches the observed flow whereas only 54% of the observed streamflow was simulated by the SWAT model prior to using the validated values from the reference catchment. In addition, the hydrological model confirmed that total surface runoff contributes the majority of flow to the surface water in the catchment (65%). Only a small proportion of the water in the creek is contributed by total base-flow (35%). This finding supports the results of the stable isotopes 16O/18O and 2H/H, which show the main source of water in the creeks is either from local precipitation or irrigation waters delivered by surface runoff; a contribution from the groundwater (baseflow) to the creeks could not be identified using 16O/18O and 2H/H. In addition, the SWAT model calculated that around 68% of the rainfall occurring in the catchment is lost through evapotranspiration reflecting the prevailing long-term drought conditions that were observed prior and during the study. Stream discharge from the forested subcatchment was an order of magnitude lower than discharge from the agricultural Six Mile Creek subcatchment. A change in land use from forestry to agriculture did not significantly change the catchment water balance, however, nutrient loads increased considerably. Conversely, a simulated change from agriculture to forestry resulted in a significant decrease of nitrogen loads. The findings of the thesis and the approach used are shown to be of value to catchment water quality monitoring on a wider scale, in particular the implications of mixed land use on nutrient forms, distributions and concentrations. The study confirms that in the tropics and subtropics the water balance is affected by extended dry periods and seasonal rainfall with intensive storm events. In particular, the comprehensive data set of inorganic and organic N and P forms in the surface and groundwaters of this subtropical setting acquired during the one year sampling program may be used in similar catchment hydrological studies where these detailed information is missing. Also, the study concludes that riparian buffer zones along the catchment drainage system attenuate the transport of nitrogen from agricultural sources in the surface water. Concentrations of N decreased from upstream to downstream locations and were negligible at the outlet of the catchment.

Water Sensitive Urban Design (WSUD) application auditing

Background WSUD implementation in the Gold Coast City Council area commenced more than a decade ago. As a result, Council is expected to be in possession of WSUD assets valued at over tens of million dollars. The Gold Coast City Council is responsible for the maintenance and long-term management of these WSUD assets. Any shortcoming in implementation of best WSUD practices can potentially result in substantial liabilities and ineffective expenditure for the Council in addition to reduced efficiencies and outcomes. This highlights the importance of periodic auditing of WSUD implementation. Project scope The overall study entailed the following tasks: * A state-of-the-art literature review of the conceptual hydraulic and water quality treatment principles, current state of knowledge in relation to industry standards, best practice and identification of knowledge gaps in relation to maintenance and management practices and potential barriers to the implementation of WSUD. * Council stakeholder interviews to understand current practical issues in relation to the implementation of WSUD and the process of WSUD application from development application approval to asset management. * Field auditing of selected WSUD systems for condition assessment and identification of possible strengths and weaknesses in implementation. * Review of the Land Development Guidelines in order to identify any gaps and to propose recommendations for improvement. Conclusions Given below is a consolidated summary of the findings of the study undertaken. State-of-the-art literature review Though the conceptual framework for WSUD implementation is well established, the underlying theoretical knowledge underpinning the treatment processes and maintenance regimes and life cycle costing are still not well understood. Essentially, these are the recurring themes in the literature, namely, the inadequate understanding of treatment processes and lack of guidance to ensure specificity of maintenance regimes and life cycle costing of WSUDs. The fundamental barriers to successful WSUD implementation are: * Lack of knowledge transfer – This essentially relates to the lack of appropriate dissemination of research outcomes and the common absence of protocols for knowledge transfer within the same organisation. * Cultural barriers – These relate to social and institutional factors, including institutional inertia and the lack of clear understanding of the benefits. * Fragmented responsibilities – This results from poor administrative integration within local councils in relation to WSUDs. * Technical barriers – These relate to lack of knowledge on operational and maintenance practices which is compounded by model limitations and the lack of long-term quantitative performance evaluation data. * Lack of engineering standards – Despite the availability of numerous guidelines which are non-enforceable and can sometimes be confusing, there is a need for stringent engineering standards. The knowledge gaps in relation to WSUDs are only closing very slowly. Some of the common knowledge gaps identified in recent publications have been recognised almost a decade ago. The key knowledge gaps identified in the published literature are: * lack of knowledge on operational and maintenance practices; * lack of reliable methodology for identifying life cycle issues including costs; * lack of technical knowledge on system performance; * lack of guidance on retrofitting in existing developments. Based on the review of barriers to WSUD implementation and current knowledge gaps, the following were identified as core areas for further investigation: * performance evaluation of WSUD devices to enhance model development and to assess their viability in the context of environmental, economic and social drivers; establishing realistic life cycle costs to strengthen maintenance and asset management practices; * development of guidelines specific to retrofitting in view of the unique challenges posed by existing urban precincts together with guidance to ensure site specificity; establishment of a process for knowledge translation for enhancing currently available best practice guidelines; * identification of drivers and overcoming of barriers in the areas of institutional fragmentation, knowledge gaps and awareness of WSUD practices. GCCC stakeholder interviews Fourteen staff members involved in WSUD systems management in the Gold Coast City Council, representing four Directorates were interviewed using a standard questionnaire. The primary issues identified by the stakeholders were: * standardisation of WSUD terminology; * clear protocols for safeguarding devices during the construction phase; * engagement of all council stakeholders in the WSUD process from the initial phase; * limitations in the Land Development Guidelines; * ensuring public safety through design; * system siting to avoid conflicts with environmental and public use of open space; * provision of adequate access for maintenance; * integration of social and ecosystem issues to ensure long-term viability of systems in relation to both, vandalism and visual recreation; * lack of performance monitoring and inadequacy of the maintenance budget; * lack of technical training for staff involved in WSUD design approvals and maintenance; incentives for developers for acting responsibly in stormwater management. Field auditing of WSUD systems A representative cross section of WSUD systems in the Gold Coast were audited in the field. The following strengths and weaknesses in WSUD implementation were noted: * The implementation of WSUD systems in the field is not consistent. * The concerns raised by the stakeholders during the interviews in relation to WSUD implementation was validated from the observations from the field auditing, particularly in relation to the following: * safeguarding of devices during the construction phase * public safety * accessibility for maintenance * lack of performance monitoring by Council to assess system performance * inadequate maintenance of existing systems to suit site specific requirements. * A treatment train approach is not being consistently adopted. * Most of the systems audited have satisfactorily catered for public safety. Accessibility for maintenance has been satisfactorily catered for in most of the systems that were audited. * Systems are being commissioned prior to construction activities being substantially completed. * The hydraulic design of most systems appears to be satisfactory. * The design intent of the systems is not always clear. Review of Land Development Guidelines The Land Development Guidelines (TDG) was extensively reviewed and the following primary issues were noted in relation to WSUD implementation: * the LDG appears to have been prepared primarily to provide guidance to developers. It is not clear to what extent the guidelines are applicable to Council staff involved in WSUD maintenance and management; * Section 13 is very voluminous and appears to be a compilation of a series of individual documents resulting in difficulties in locating specific information, a lack of integration and duplication of information; * the LDG has been developed with a primary focus on new urban precinct development and the retrofitting of systems in existing developments has not been specifically discussed; * WSUDs are discussed in two different sections in the LDG and it is not clear which section takes precedence as there are inconsistencies between the two sections; there is inconsistent terminology being used; * there is a need for consolidation of information provided in different sections in the LDG; * there are inconsistencies in the design criteria provided; * there is a need for regular updating of the LDG to ensure that the information provided encompasses the state-of-the-art; * there is limited guidance provided for the preparation of maintenance plans and life cycle costing to assist developers in asset handover and to assist Council staff in assessment. * Based on these observations, eleven recommendations have been provided which are discussed below. Additionally, the stakeholder provided the following specific comments during the interviews in relation to the LDG: * lack of flexibility to cover the different stages of the life cycle of the systems; * no differentiation in projects undertaken by developers and Council; * inadequate information with regards to safety issues such as maximum standing water depth, fencing and safety barriers and public access; * lack of detailed design criteria in relation to Crime Prevention through Environmental Design, safety, amenity, environment, surrounding uses and impacts on surroundings; * inadequate information regarding maintenance requirements specific to the assessment and compliance phases; * recommendations for plantings are based primarily on landscape requirements rather than pollutant uptake capability. Recommendations With regards to the Land Development Guidelines, the following specific recommendations are provided: 1. the relevant sections and their extent of applicability to Council should be clearly identified; 2. integration of the different subsections within Section 13 and re-formatting the document for easy reference; 3. the maintenance guidelines provided in Section 13 should be translated to a maintenance manual for guidance of Council staff; 4. should consider extending the Guidelines to specifically encompass retrofitting of WSUD systems to existing urban precincts; 5. Section 3 needs to be revised to be made consistent with Section 13, to ensure priority for WSUD practices in urban precincts and to move away from conventional stormwater drainage design such as kerb and channelling; 6. it would also be good to specify as to which Section takes predominance in relation to stormwater drainage. It is expected that Section 13 would take predominance over the other sections in the LDG; 7. terminology needs to be made consistent to avoid confusion among developers and Council staff. Water Sensitive Urban Design is the term commonly used in Australia for stormwater quality treatment, rather than Stormwater Quality Improvement Devices. This once again underlines the need for ensuring consistency between Section 3 and Section 13; 8. it would also be good if there is a glossary of commonly used terms in relation to WSUD for use by all stakeholders and which should also be reflected in the LDG; 9. consolidation of all WSUD information into one section should be considered together with appropriate indicators in other LDG Sections regarding the availability of WSUD information. Ensuring consistency in the information provided is implied; 10. Section 13 should be updated at regular intervals to ensure the incorporation of the latest in research outcomes and incorporating criteria and guidance based on the state-of-the-art knowledge. The updating could be undertaken, say, in five year cycles. This would help to overcome the current lack of knowledge transfer; 11. the Council should consider commissioning specialised studies to extend the current knowledge base in relation to WSUD maintenance and life cycle costing. Additionally, Recommendation 10 is also applicable in this instance. The following additional recommendations are made based on the state-of-the-art literature review, stakeholder interviews and field auditing of WSUD systems: 1. Performance monitoring of existing systems to assess improvements to water quality, identify modifications and enhancements to improve performance; 2. Appropriate and monitored maintenance during different phases of development of built assets over time is needed to investigate the most appropriate time/phase of development to commission the final WSUD asset. 3. Undertake focussed investigations in the areas of WSUD maintenance and asset management in order to establish more realistic life cycle costs of systems and maintenance schedules; 4. the engagement of all relevant Council stakeholders from the initial stage of concept planning through to asset handover, and ongoing monitoring. This close engagement of internal stakeholders will assist in building a greater understanding of responsibilities and contribute to overcoming constraints imposed by fragmented responsibilities; 5. the undertaking of a public education program to inform the community of the benefits and ecosystem functions of WSUD systems; 6. technical training to impart state-of-the-art knowledge to staff involved in the approval of designs and maintenance and management of WSUD projects; 7. during the construction phase, it is important to ensure that appropriate measures to safeguard WSUD devices are implemented; 8. risks associated with potential public access to open water zones should be minimised with the application of appropriate safety measures; 9. system siting should ensure that potential conflicts are avoided with respect to public and ecosystem needs; 10. integration of social and ecosystem issues to ensure long-term viability of systems; provide incentives to developers who are proactive and responsible in the area of stormwater management.

Selecting rainfall events for effective Water Sensitive Urban Design (WSUD) implementation

The current approach for protecting the receiving water environment from urban stormwater pollution is the adoption of structural measures commonly referred to as Water Sensitive Urban Design (WSUD). The treatment efficiency of WSUD measures closely depends on the design of the specific treatment units. As stormwater quality can be influenced by rainfall characteristics, the selection of appropriate rainfall events for treatment design is essential to ensure the effectiveness of WSUD systems. Based on extensive field investigation of four urban residential catchments and computer modelling, this paper details a technically robust approach for the selection of rainfall events for stormwater treatment design using a three-component model. The modelling outcomes indicate that selecting smaller average recurrence interval (ARI) events with high intensity-short duration as the threshold for the treatment system design is the most feasible since these events cumulatively generate a major portion of the annual pollutant load compared to the other types of rainfall events, despite producing a relatively smaller runoff volume. This implies that designs based on small and more frequent rainfall events rather than larger rainfall events would be appropriate in the context of efficiency in treatment performance, cost-effectiveness and possible savings in land area needed.

Atmospheric particles as a pollutant source in the urban water environment in Sri Lanka – current research trends and future directions

Human and ecosystem health impacts imposed by water pollution are a major problem in the urban areas of Sri Lanka. A primary source of pollutants to urban water sources is atmospheric particles. Hence, it is important to develop a detailed understanding of atmospheric particle characteristics, their sources of origin and the transport pathways. Several research studies have been conducted in Sri Lanka on atmospheric pollution and these studies have tended to differ in their scope, study region and the investigated pollutants. The objectives of this paper are: (1) to report the outcomes of a detailed state-of-art literature review of atmospheric pollution related studies in Sri Lanka to understand the current trends and (2) to discuss the future research activities necessary to generate the important knowledge required for the development of effective strategies to control the adverse impacts of atmospheric pollution on urban waterways.

Working knowledge for collaborative water planning in Australia’s Wet Tropics region

Cooperation between multiple environmental decision-makers and activities is necessary to address the impacts of diffuse sources of agricultural pollution on the water quality entering Australia’s Great Barrier Reef (GBR). Water planning efforts requires available knowledge to inform this co-operative water program implementation and reform. This paper uses knowledge sharing, translation and feedback features of collaboration as a way to assess knowledge work practices during key phases of the water planning process. This enabled a systematic review of knowledge work practices in partnership with collaborative water planning groups established to inform water quality program investment decisions in the GBR’s Wet Tropics region. This research builds on the growing academic and policy interest in the conditions required to enable different types of knowledge to be successfully used for policy-making by focusing on when, how and why knowledge work to meet these conditions is required.

Sustainable Urban Water Environment : Climate, Pollution and Adaptation

"This multi-disciplinary book provides practical solutions for safeguarding the sustainability of the urban water environment. Firstly, the importance of the urban water environment is highlighted and the major problems urban water bodies face and strategies to safeguard the water environment are explored. Secondly, the diversity of pollutants entering the water environment through stormwater runoff are discussed and modelling approaches for factoring in climate change and future urban and transport scenarios are proposed. Thirdly, by linking the concepts of sustainable urban ecosystems and sustainable urban and transport development, capabilities of two urban sustainability assessment models are demonstrated."--publisher website

Secure and safe water supplies in remote Australian and rural Sri Lankan regions : common issues and emerging responses

Most urban dwelling Australians take secure and safe water supplies for granted. That is, they have an adequate quantity of water at a quality that can be used by people without harm from human and animal wastes, salinity and hardness or pollutants from agriculture and manufacturing industries. Australia wide urban and peri-urban dwellers use safe water for all domestic as well as industrial purposes. However, this is not the situation remote regions in Australia where availability and poor quality water can be a development constraint. Nor is it the case in Sri Lanka where people in rural regions are struggling to obtain a secure supply of water, irrespective of it being safe because of the impact of faecal and other contaminants. The purposes of this paper are to overview: the population and environmental health challenges arising from the lack of safe water in rural and remote communities; response pathways to address water quality issues; and the status of and need for integrated catchment management (ICM) in selected remote regions of Australia and vulnerable and lagging rural regions in Sri Lanka. Conclusions are drawn that focus on the opportunity for inter-regional collaborations between Australia and Sri Lanka for the delivery of safe water through ICM.

Nitrous oxide emissions from fertilized, irrigated cotton (Gossypium hirsutum L.) in the Aral Sea Basin, Uzbekistan : influence of nitrogen applications and irrigation practices

Nitrous oxide emissions were monitored at three sites over a 2-year period in irrigated cotton fields in Khorezm, Uzbekistan, a region located in the arid deserts of the Aral Sea Basin. The fields were managed using different fertilizer management strategies and irrigation water regimes. N2O emissions varied widely between years, within 1 year throughout the vegetation season, and between the sites. The amount of irrigation water applied, the amount and type of N fertilizer used, and topsoil temperature had the greatest effect on these emissions. Very high N2O emissions of up to 3000 μg N2O-N m−2 h−1 were measured in periods following N-fertilizer application in combination with irrigation events. These “emission pulses” accounted for 80–95% of the total N2O emissions between April and September and varied from 0.9 to 6.5 kg N2O-N ha−1.. Emission factors (EF), uncorrected for background emission, ranged from 0.4% to 2.6% of total N applied, corresponding to an average EF of 1.48% of applied N fertilizer lost as N2O-N. This is in line with the default global average value of 1.25% of applied N used in calculations of N2O emissions by the Intergovernmental Panel on Climate Change. During the emission pulses, which were triggered by high soil moisture and high availability of mineral N, a clear diurnal pattern of N2O emissions was observed, driven by daily changes in topsoil temperature. For these periods, air sampling from 8:00 to 10:00 and from 18:00 to 20:00 was found to best represent the mean daily N2O flux rates. The wet topsoil conditions caused by irrigation favored the production of N2O from NO3− fertilizers, but not from NH4+ fertilizers, thus indicating that denitrification was the main process causing N2O emissions. It is therefore argued that there is scope for reducing N2O emission from irrigated cotton production; i.e. through the exclusive use of NH4+ fertilizers. Advanced application and irrigation techniques such as subsurface fertilizer application, drip irrigation and fertigation may also minimize N2O emission from this regionally dominant agro-ecosystem.

Assessment of Geogenic Contaminants in Water Co-Produced with Coal Seam Gas Extraction in Queensland, Australia : Implications for Human Health Risk

Organic compounds in Australian coal seam gas produced water (CSG water) are poorly understood despite their environmental contamination potential. In this study, the presence of some organic substances is identified from government-held CSG water-quality data from the Bowen and Surat Basins, Queensland. These records revealed the presence of polycyclic aromatic hydrocarbons (PAHs) in 27% of samples of CSG water from the Walloon Coal Measures at concentrations <1 µg/L, and it is likely these compounds leached from in situ coals. PAHs identified from wells include naphthalene, phenanthrene, chrysene and dibenz[a,h]anthracene. In addition, the likelihood of coal-derived organic compounds leaching to groundwater is assessed by undertaking toxicity leaching experiments using coal rank and water chemistry as variables. These tests suggest higher molecular weight PAHs (including benzo[a]pyrene) leach from higher rank coals, whereas lower molecular weight PAHs leach at greater concentrations from lower rank coal. Some of the identified organic compounds have carcinogenic or health risk potential, but they are unlikely to be acutely toxic at the observed concentrations which are almost negligible (largely due to the hydrophobicity of such compounds). Hence, this study will be useful to practitioners assessing CSG water related environmental and health risk.

The Cressbrook Creek alluvial aquifer system, Southeast Queensland : hydrochemistry and isotopes to determine hydrological processes and response to floods

This study developed an understanding of hydrological processes within the Cressbrook Creek catchment of the upper Brisbane River, in particular for the alluvial aquifers. Those aquifers within the lower catchment are used for intensive irrigation, and have been impacted by long-term drought followed by flooding. The study utilised water chemistry, isotopic characters and hydraulic measurements to determine factors such as recharge, links between creeks and groundwater, and variations in water quality. The catchment-wide study will enable improved management of the local water resources.

The use of new generation geosynthetics in water treatment

The importance of clean drinking water in any community is absolutely vital if we as the consumers are to sustain a life of health and wellbeing. Suspended particles in surface waters not only provide the means to transport micro-organisms which can cause serious infections and diseases, they can also affect the performance capacity of a water treatment plant. In such situations pre-treatment ahead of the main plant is recommended. Previous research carried out using non-woven synthetic as a pre-filter materials for protecting slow sand filters from high turbidity showed that filter run times can be extended by several times and filters can be regenerated by simply removing and washing of the fabric ( Mbwette and Graham, 1987 and Mbwette, 1991). Geosynthetic materials have been extensively used for soil retention and dewatering in geotechnical applications and little research exists for the application of turbidity reduction in water treatment. With the development of new materials in geosynthetics today, it was hypothesized that the turbidity removal efficiency can be improved further by selecting appropriate materials. Two different geosynthetic materials (75 micron) tested at a filtration rate of 0.7 m/h yielded 30-45% reduction in turbidity with relatively minor head loss. It was found that the non-woven geotextile Propex 1701 retained the highest performance in both filtration efficiency and head loss across the varying turbidity ranges in comparison to other geotextiles tested. With 5 layers of the Propex 1701 an average percent reduction of approximately 67% was achieved with a head loss average of 4mm over the two and half hour testing period. Using the data collected for the Propex 1701 a mathematical model was developed for predicting the expected percent reduction given the ability to control the cost and as a result the number of layers to be used in a given filtration scenario.

Emerging water treatment technologies for decentralised systems : an overview of selected systems suited for application in towns and settlements in remote and very remote regions of Australia and vulnerable and lagging rural regions in Sri Lanka

The primary purpose of this paper is to overview a selection of advanced water treatment technology systems that are suited for application in towns and settlements in remote and very remote regions of Australia and vulnerable and lagging rural regions in Sri Lanka. This recognises that sanitation and water treatment are inextricably linked and both are needed to reduce risks to environment and population health from contaminated water sources. For both Australia and Sri Lanka only a small fraction of the settlements in rural and remote regions are connected to water treatment facilities and town water supplies. In Australia’s remote/very remote regions raw water is drawn from underground sources and rainwater capture. Most settlements in rural Sri Lanka rely on rivers, reservoirs, wells, springs or carted water. Furthermore, Sri Lanka has more than 25,000 hand pumped tube wells which saved the communities during recent droughts. Decentralised water supply systems offer the opportunity to provide safe drinking water to these remote/very remote and rural regions where centralised systems are not feasible due to socio-cultural, economic, political, technological reasons. These systems reduce health risks from contaminated water supplies. In remote areas centralized systems fail due to low population density and less affordability. Globally, a new generation of advanced water treatment technologies are positioned to make a major impact on the provision of safe potable water in remote/very remote regions in Australia and rural regions in Sri Lanka. Some of these systems were developed for higher income countries. However, with careful selection and further research they can be tailored to match local socio-economic conditions and technical capacity. As such, they can equally be used to provide decentralised water supply in communities in developed and developing countries such as Australia and Sri Lanka.