Anna Lintern

Uncertainties in historical pollution data from sedimentary records from an Australian urban floodplain lake

Publisher: Elsevier BV

Date: 05-2018

DOI: 10.1016/J.JHYDROL.2018.03.055

Shifts in stream salt loads during and after prolonged droughts

Publisher: Wiley

Date: 06-2023

DOI: 10.1002/HYP.14901

Abstract: It has been widely assumed that after prolonged droughts, catchment runoff recovers to pre‐drought levels. This assumption has recently been evaluated and challenged using empirical observations. However, water quality response and recovery, or otherwise, during and after prolonged droughts remains an open question. Answering this question potentially identifies any changes in catchment hydrological processes and water balance (e.g., the proportion of groundwater contribution to streamflow), thus informing the mechanisms for runoff non‐recovery after prolonged drought. Water quality responses to drought can also inform any long‐term water quality changes beyond what is observable from trend analyses. Here stream salt load changes were investigated using hidden Markov models (HMMs), where monthly rainfall was included as a predictor of stream salt loads. Monthly riverine salt fluxes at eight sites in Victoria (Australia) were examined before, during and after a prolonged drought in South‐East Australia—the Millennium Drought. Two‐state models, where salt loads varied between ‘normal’ and ‘low’ states, were found to better predict in‐stream salt loads compared to single‐state models. The results showed that catchments shifted to a low salt load state generally after the catchment changed to a low runoff state. As groundwater is understood to be the major source of salts in these catchments, this suggests that reductions in groundwater flow into rivers occur as a result of the shift to a lower runoff state. Understanding how readily water quality in catchments shift to different states during and after prolonged droughts enables appropriate catchment management based on our understanding of changes to catchment hydrology.

Escherichia coli survival and transfer in estuarine bed sediments

Publisher: Wiley

Date: 03-05-2018

DOI: 10.1002/RRA.3281

River Bank Erosion and the Influence of Environmental Flow Management

Publisher: Springer Science and Business Media LLC

Date: 06-04-2017

DOI: 10.1007/S00267-017-0857-9

Abstract: Environmental flows aim to influence river hydrology to provide appropriate physical conditions for ecological functioning within the restrictions of flow regulation. The hydrologic characteristics of flow events, however, may also lead to unintended morphologic effects in rivers, such as increases in riverbank erosion beyond natural rates. This may negatively impact habitat for biota, riparian infrastructure, and land use. Strategic environmental flow delivery linked to monitoring and adaptive management can help mitigate risks. We monitor riverbank condition (erosion and deposition) relative to environmental flows on the Goulburn River, Victoria, Australia. We describe the process of adaptive management aimed at reducing potential impacts of flow management on bank condition. Field measurements (erosion pins) quantify the hydrogeomorphic response of banks to the delivery of planned and natural flow events. Managed flows provide opportunities for monitoring riverbank response to flows, which in turn informs planning. The results demonstrate that environmental flows have little influence on bank erosion and visual perceptions in the absence of monitoring are an unreliable guide. This monitoring project represents a mutually beneficial, science-practice partnership demonstrating that a traditional 'know then do' approach can be foreshortened by close collaboration between researchers and managers. To do so requires transparent, often informal lines of communication. The benefits for researchers-a more strategic and targeted approach to monitoring activities and benefits for the practitioners-reduced time between actions and understanding response mean that a learn by doing approach is likely to have better outcomes for researchers, stakeholders, the public, and the environment.

The impact of stormwater biofilter design and operational variables on nutrient removal - a statistical modelling approach

Publisher: Elsevier BV

Date: 2021

DOI: 10.1016/J.WATRES.2020.116486

Identifying heavy metal levels in historical flood water deposits using sediment cores

Publisher: Elsevier BV

Date: 11-2016

DOI: 10.1016/J.WATRES.2016.08.041

Abstract: When designing mitigation and restoration strategies for aquatic systems affected by heavy metal contamination, we must first understand the sources of these pollutants. In this study, we introduce a methodology that identifies the heavy metal levels in floodplain lake sediments deposited by one source fluvial floods. This is done by comparing sediment core heavy metal profiles (i.e., historical pollution trends) to physical and chemical properties of sediments in these cores (i.e., historical flooding trends). This methodology is applied to Willsmere and Bolin Billabongs, two urban floodplain lakes (billabongs) of the Yarra River (South-East Australia). Both billabongs are periodically inundated by flooding of the Yarra River and one billabong (Willsmere Billabong) is connected to an urban stormwater drainage network. 1-2-m long sediment cores (containing sediment deposits up to 500 years old) were taken from the billabongs and analysed for heavy metal concentrations (arsenic, chromium, copper, lead, nickel, zinc). In cores from both billabongs, arsenic concentrations are high in the flood-borne sediments. In Bolin Billabong, absolute metal levels are similar in flood and non-flood deposits. In Willsmere Billabong, absolute copper, lead and zinc levels were generally lower in fluvial flood-borne sediments in the core compared to non-fluvial sediments. This suggests that heavy metal concentrations in Bolin Billabong sediments are relatively similar regardless of whether or not fluvial flooding is occurring. However for Willsmere Billabong, heavy metal concentrations are high when overland runoff, direct urban stormwater discharges or atmospheric deposition is occurring. As such, reducing the heavy metal concentrations in these transport pathways will be of great importance when trying to reduce heavy metal concentrations in Willsmere Billabong sediments. This study presents a proof-of-concept that can be applied to other polluted aquatic systems, to understand the importance of river floods in the contamination of the bed sediments of aquatic systems. As a cost effective and less time consuming alternative to extensive field monitoring, our proposed method can be used to identify the key sources of pollution and therefore support the development of effective management strategies.

Using sediment cores to establish targets for the remediation of aquatic environments

Publisher: IWA Publishing

Date: 19-10-2015

DOI: 10.2166/WST.2015.525

Abstract: When assigning site-specific restoration targets for deteriorating aquatic systems, it is necessary to have an understanding of the undisturbed or background state of the system. However, the site-specific characteristics of aquatic systems prior to disturbance are mostly unknown, due to the lack of historical water and sediment quality data. This study aims to introduce a method for filling this gap in our understanding, using dated sediment cores from the beds of aquatic environments. We used Bolin Billabong, a floodplain lake of the Yarra River (South-East Australia), as a case study to demonstrate the application of this method. We identified the concentrations of aluminium, cadmium, chromium, copper, iron, lead, manganese, nickel, tin and zinc at 8 cm intervals through the sediment core. This showed that aluminium, chromium, copper, iron, lead, nickel, tin and zinc concentrations in Bolin Billabong sediments significantly increased after European settlement in the river catchment in the mid-19th century. The differences between current Australian sediment quality guidelines trigger values and the background metal concentrations in Bolin Billabong sediments underscore the value of using locally relevant background toxicant concentrations when setting water and sediment quality targets.

Presence and survival of culturable Campylobacter spp. and Escherichia coli in a temperate urban estuary

Publisher: Elsevier BV

Date: 11-2016

DOI: 10.1016/J.SCITOTENV.2016.06.195

Abstract: Urban estuaries throughout the world typically contain elevated levels of faecal contamination, the extent of which is generally assessed using faecal indicator organisms (FIO) such as Escherichia coli. This study assesses whether the bacterial FIO, E. coli is a suitable surrogate for C ylobacter spp., in estuaries. The presence and survival dynamics of culturable E. coli and C ylobacter spp. are compared in the water column, bank sediments and bed sediments of the Yarra River estuary (located in Melbourne, Australia). The presence of E. coli did not necessarily indicate detectable levels of C ylobacter spp. in the water column, bed and bank sediments, but the inactivation rates of the two bacteria were similar in the water column. A key finding of the study is that E. coli and C ylobacter spp. can survive for up to 14days in the water column and up to 21days in the bed and bank sediments of the estuary. Preliminary data presented in this study also suggests that the inactivation rates of the two bacteria may be similar in bed and bank sediments. This undermines previous hypotheses that C ylobacter spp. cannot survive outside of its host and indicates that public health risks can persist in aquatic systems for up to three weeks after the initial contamination event.

The influence of climate on water chemistry states and dynamics in rivers across Australia

Publisher: Wiley

Date: 12-2021

DOI: 10.1002/HYP.14423

Abstract: For effective water quality management and policy development, spatial variability in the mean concentrations and dynamics of riverine water quality needs to be understood. Using water chemistry (calcium, electrical conductivity, nitrate‐nitrite, soluble reactive phosphorus, total nitrogen, total phosphorus and total suspended solids) data for up to 578 locations across the Australian continent, we assessed the impact of climate zones (arid, Mediterranean, temperate, subtropical, tropical) on (i) inter‐annual mean concentration and (ii) water chemistry dynamics as represented by constituent export regimes (ratio of the coefficients of variation of concentration and discharge) and export patterns (slope of the concentration‐discharge relationship). We found that inter‐annual mean concentrations vary significantly by climate zones and that spatial variability in water chemistry generally exceeds temporal variability. However, export regimes and patterns are generally consistent across climate zones. This suggests that intrinsic properties of in idual constituents rather than catchment properties determine export regimes and patterns. The spatially consistent water chemistry dynamics highlights the potential to predict riverine water quality across the Australian continent, which can support national riverine water quality management and policy development.

Key factors influencing differences in stream water quality across space

Publisher: Wiley

Date: 24-10-2018

DOI: 10.1002/WAT2.1260

Abstract: Globally, many rivers are experiencing declining water quality, for ex le, with altered levels of sediments, salts, and nutrients. Effective water quality management requires a sound understanding of how and why water quality differs across space, both within and between river catchments. Land cover, land use, land management, atmospheric deposition, geology and soil type, climate, topography, and catchment hydrology are the key features of a catchment that affect: (1) the amount of suspended sediment, nutrient, and salt concentrations in catchments (i.e., the source), (2) the mobilization ,and (3) the delivery of these constituents to receiving waters. There are, however, complexities in the relationship between landscape characteristics and stream water quality. The strength of this relationship can be influenced by the distance and spatial arrangement of constituent sources within the catchment, cross correlations between landscape characteristics, and seasonality. A knowledge gap that should be addressed in future studies is that of interactions and cross correlations between landscape characteristics. There is currently limited understanding of how the relationships between landscape characteristics and water quality responses can shift based on the other characteristics of the catchment. Understanding the many forces driving stream water quality and the complexities and interactions in these forces is necessary for the development of successful water quality management strategies. This knowledge could be used to develop predictive models, which would aid in forecasting of riverine water quality. WIREs Water 2018, 5:e1260. doi: 10.1002/wat2.1260 This article is categorized under: Science of Water Hydrological Processes Science of Water Water Quality

Engineering a biofilters microbiome with activated carbon and bioaugmentation to improve stormwater micropollutant removal

Publisher: Elsevier BV

Date: 11-2023

DOI: 10.1016/J.ETI.2023.103338

Solving the puzzle of mercury fate and emissions by coal-fired power plants: The potential of hydrodynamic-atmospheric modelling

Publisher: Elsevier BV

Date: 11-2021

DOI: 10.1016/J.ENVPOL.2021.117579

What Are the Key Catchment Characteristics Affecting Spatial Differences in Riverine Water Quality?

Publisher: American Geophysical Union (AGU)

Date: 10-2018

DOI: 10.1029/2017WR022172

Abstract: This study uses water‐quality data collected over 20 years, from 102 predominantly rural sites across Victoria, Australia, to further our understanding of spatial variability in riverine water quality. We focus on concentrations of total suspended solids, total phosphorus, filterable reactive phosphorus, total Kjeldahl nitrogen, nitrate/nitrite (NO x ), and electrical conductivity. We used an exhaustive search approach to identify the linear models that best link catchment characteristics to time‐averaged constituent concentrations. We ran additional analyses to (1) assess the performance of these models under drought conditions, and (2) understand the key drivers of site‐level variability (standard deviations) of constituent concentrations. Natural catchment characteristics appear to have a greater effect on spatial differences in average constituent concentrations. Performance of the statistical models of time‐averaged constituent concentrations varied, and spatial variability in mean electrical conductivity levels could be more readily explained by catchment characteristics compared to more reactive nutrients. Notwithstanding, the models performed relatively well under varying hydrologic conditions for most constituents. As such, these models provide an insight into the key factors affecting spatial variability in average stream water‐quality conditions. We also identified that hydrologic, climatic, and topographic characteristics of the catchment helped explain the spatial variability in temporal changes in constituents. After calibration and validation, these models of both average water quality and variability in water quality could be used to forecast stream water‐quality responses to future land use, climate, or soil and land management changes.

Best Management Practices for Diffuse Nutrient Pollution: Wicked Problems Across Urban and Agricultural Watersheds

Publisher: American Chemical Society (ACS)

Date: 09-07-2020

DOI: 10.1021/ACS.EST.9B07511

Digging up the dirty past: evidence for stormwater’s contribution to pollution of an urban floodplain lake

Publisher: CSIRO Publishing

Date: 2015

DOI: 10.1071/MF14111

Abstract: Negative effects of urbanisation on the health of aquatic environments are well recognised but more data are needed for an accurate assessment of the particular effects of residential development on the health of aquatic systems. This study explores the relationship between residential growth and increasing pollution, by analysing temporal trends of chemical fluxes into Willsmere Billabong – an urban floodplain lake of the Yarra River in South-East Australia. Sediment cores were extracted to reveal depositions over three centuries (~1700–2012). The cores were sub-s led at high resolution and analysed for heavy metals, polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs). Pollutant concentrations in the sediments appear to have been significantly affected by residential development in the local catchment. Normalised concentration profiles show these effects to be exacerbated from the mid-20th century, after a stormwater drain was installed in the billabong. The study suggests that urban stormwater management techniques are critical for the protection of aquatic systems incorporated into residential zones.

Key Factors Affecting Temporal Variability in Stream Water Quality

Publisher: American Geophysical Union (AGU)

Date: 2019

DOI: 10.1029/2018WR023370

Abstract: Understanding the factors that influence temporal variability in water quality is critical for designing water quality management strategies. In this study, we explore the key factors that affect temporal variability in stream water quality across multiple catchments using a Bayesian hierarchical model. We apply this model to a case study data set consisting of monthly water quality measurements obtained over a 20‐year period from 102 water quality monitoring sites in the state of Victoria (Southeast Australia). We investigate six water quality constituents: total suspended solids, total phosphorus, filterable reactive phosphorus, total Kjeldahl nitrogen, nitrate‐nitrite (NO x ), and electrical conductivity. We find that same‐day streamflow has the greatest effect on water quality variability for all constituents. Additional important predictors include soil moisture, antecedent streamflow, vegetation cover, and water temperature. Overall, the models do not explain a large proportion of temporal variation in water quality, with Nash‐Sutcliffe coefficients lower than 0.49. However, when considering performance on a site‐by‐site basis, we see high model performance in some locations, with Nash‐Sutcliffe coefficients of up to 0.8 for NO x and electrical conductivity. The effect of the temporal predictors on water quality varies between sites, which should be explored further for potential spatial patterns in future studies. There is also potential for further extension of these temporal variability models into a predictive spatiotemporal model of riverine constituent concentrations, which will be a useful tool to inform decision making for catchment water quality management.

Source tracking using microbial community fingerprints: Method comparison with hydrodynamic modelling

Publisher: Elsevier BV

Date: 02-2017

DOI: 10.1016/J.WATRES.2016.11.043

Abstract: Urban estuaries around the world are experiencing contamination from diffuse and point sources, which increases risks to public health. To mitigate and manage risks posed by elevated levels of contamination in urban waterways, it is critical to identify the primary water sources of contamination within catchments. Source tracking using microbial community fingerprints is one tool that can be used to identify sources. However, results derived from this approach have not yet been evaluated using independent datasets. As such, the key objectives of this investigation were: (1) to identify the major sources of water responsible for bacterial loadings within an urban estuary using microbial source tracking (MST) using microbial communities and (2) to evaluate this method using a 3-dimensional hydrodynamic model. The Yarra River estuary, which flows through the city of Melbourne in South-East Australia was the focus of this study. We found that the water sources contributing to the bacterial community in the Yarra River estuary varied temporally depending on the estuary's hydrodynamic conditions. The water source apportionment determined using microbial community MST correlated to those determined using a 3-dimensional hydrodynamic model of the transport and mixing of a tracer in the estuary. While there were some discrepancies between the two methods, this investigation demonstrated that MST using bacterial community fingerprints can identify the primary water sources of microorganisms in an estuarine environment. As such, with further optimization and improvements, microbial community MST has the potential to become a powerful tool that could be practically applied in the mitigation of contaminated aquatic systems.

Sediment cores as archives of historical changes in floodplain lake hydrology

Publisher: Elsevier BV

Date: 02-2016

DOI: 10.1016/J.SCITOTENV.2015.11.153

Abstract: Anthropogenic activities are contributing to the changing hydrology of rivers, often resulting in their degradation. Understanding the drivers and nature of these changes is critical for the design and implementation of effective mitigation strategies for these systems. However, this can be hindered by gaps in historical measured flow data. This study therefore aims to use sediment cores to identify historical hydrological changes within a river catchment. Sediment cores from two floodplain lakes (billabongs) in the urbanised Yarra River catchment (Melbourne, South-East Australia) were collected and high resolution images, trends in magnetic susceptibility and trends in elemental composition through the sedimentary records were obtained. These were used to infer historical changes in river hydrology to determine both average trends in hydrology (i.e., coarse temporal resolution) as well as discrete flood layers in the sediment cores (i.e., fine temporal resolution). Through the 20th century, both billabongs became increasingly disconnected from the river, as demonstrated by the decreasing trends in magnetic susceptibility, particle size and inorganic matter in the cores. Additionally the number of discrete flood layers decreased up the cores. These reconstructed trends correlate with measured flow records of the river through the 20th century, which validates the methodology that has been used in this study. Not only does this study provide evidence on how natural catchments can be affected by land-use intensification and urbanisation, but it also introduces a general analytical framework that could be applied to other river systems to assist in the design of hydrological management strategies.

Stormwater biofilters as barriers against Campylobacter jejuni, Cryptosporidium Oocysts and adenoviruses; results from a laboratory trial

Publisher: MDPI AG

Date: 06-12-2017

DOI: 10.3390/W9120949

Using sedimentary prokaryotic communities to assess historical changes in the Gippsland Lakes

Publisher: Wiley

Date: 10-10-2023

DOI: 10.1111/FWB.14182

Assessing environmental contamination from metal emission and relevant regulations in major areas of coal mining and electricity generation in Australia

Publisher: Elsevier BV

Date: 08-2020

DOI: 10.1016/J.SCITOTENV.2020.137398

Controls on Spatial Variability in Mean Concentrations and Export Patterns of River Chemistry Across the Australian Continent

Publisher: American Geophysical Union (AGU)

Date: 12-2022

DOI: 10.1029/2022WR032365

Abstract: The state and dynamics of river chemistry are influenced by both anthropogenic and natural catchment characteristics. However, understanding key controls on catchment mean concentrations and export patterns comprehensively across a wide range of climate zones is still lacking, as most of this research is focused on temperate regions. In this study, we investigate the catchment controls on mean concentrations and export patterns (concentration – discharge relationship, C–Q slope) of river chemistry, using a long‐term data set of up to 507 sites spanning five climate zones (i.e., arid, Mediterranean, temperate, subtropical, tropical) across the Australian continent. We use Bayesian model averaging (BMA) and hierarchical modeling (BHM) approaches to predict the mean concentrations and export patterns and compare the relative importance of 26 catchment characteristics (e.g., topography, climate, land use, land cover, soil properties and hydrology). Our results demonstrate that mean concentrations result from the interaction of catchment indicators and anthropogenic factors (i.e., land use, topography and soil), while export patterns are influenced by topography. We also found that incorporating the effects of climate zones in a BHM framework improved the predictability of both mean concentrations and C–Q slopes, suggesting the importance of climatic controls on hydrological and biogeochemical processes. Our study provides insights into the contrasting effects of catchment controls across different climate zones. Investigating those controls can inform sustainable water quality management strategies that consider the potential changes in river chemistry state and export behavior.

Monash University

Location: Australia

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Discovery Projects - Grant ID: DP220101967

Start Date: 03-2022

End Date: 03-2025

Amount: $430,783.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP220100823

Start Date: 04-2023

End Date: 04-2026

Amount: $508,976.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP190100755

Start Date: 02-2021

End Date: 12-2025

Amount: $870,987.00

Funder: Australian Research Council