Environmental impact of coal mining and coal seam gas production on surface water quality in the Sydney basin, Australia

Abstract

The extraction of coal and coal seam gas (CSG) will generate produced water that, if not adequately treated, will pollute surface and groundwater systems. In Australia, the discharge of produced water from coal mining and related activities is regulated by the state environment agency through a pollution licence. This licence sets the discharge limits for a range of analytes to protect the environment into which the produced water is discharged. This study reports on the impact of produced water from coal mine activities located within or discharging into high conservation environments, such as National Parks, in the outer region of Sydney, Australia. The water samples upstream and downstream from the discharge points from six mines were taken, and 110 parameters were tested. The results were assessed against a water quality index (WQI) which accounts for pH, turbidity, dissolved oxygen, biochemical oxygen demand, total dissolved solids, total phosphorus, nitrate nitrogen and E .coli. The water quality assessment based on the trace metal contents against various national maximum admissible concentration (MAC) and their corresponding environmental impacts was also included in the study which also established a base value of water quality for further study. The study revealed that impacted water downstream of the mine discharge points contained higher metal content than the upstream reference locations. In many cases, the downstream water was above the Australia and New Zealand Environment Conservation Council and international water quality guidelines for freshwater stream. The major outliers to the guidelines were aluminium (Al), iron (Fe), manganese (Mn), nickel (Ni) and zinc (Zn). The WQI of surface water at and downstream of the discharge point was lower when compared to upstream or reference conditions in the majority of cases. Toxicology indices of metals present in industrial discharges were used as an additional tool to assess water quality, and the newly proposed environmental water quality index (EWQI) lead to better trend in the impact of coal and coal seam gas mining activities on surface water quality when compared to the upstream reference water samples. Metal content limits were based on the impact points assigned by the Agency for Toxic Substances and Disease Registry, USA. For environmental and health impact assessment, the approach used in this study can be applied as a model to provide a basis to assess the anthropogenic contribution from the industrial and mining activities on the environment.

Water quality assessment of Australian ports using water quality evaluation indices

“…The environmental water quality assessment index is a newly proposed index by [ 36 ] which is calculated by multiplying the concentration of each contaminant measured in the water samples with the corresponding hazard intensity to determine the water quality impact. The hazard intensity of each parameter was determined according to the total score assigned by the Toxicological Profiles of the Priority List of Hazardous Substances prepared by the Agency for Toxic Substances and Disease Registry (ATSDR), the Division of Toxicology and Environmental Medicine, Atlanta, USA [ 37 ].…”

Assessment of Heavy Metals Contamination in Drinking Water of Garmian Region, Iraq

“…Application of water pollution indices is associated with various statistical analytical techniques to interpret and classify the obtained water quality data sets. However, among the numerous available statistical techniques, the univariate ANOVA, the bivariate correlation coefficient matrix CM, and the multivariate cluster analysis CA are used for heavy metals impact on water quality [35], [36]. Sometimes, these statistical become helpful as water quality results may require additional explanations to identify source and way of the contamination.…”

Ecobiology of coal mines and spoils

“…Increasing demand for coal is known to destabilize the ecosystem around the mining area, which is contrary to the objectives of sustainable development (Kar and Palit, 2017). During the process of mining, variety of materials are washed away as discharge into the waterways, which flows downstream and can contaminate water bodies with various metals (Ali et al, 2017. These heavy metals discharged from coal mines may be consumed by some aquatic organisms, whereas the low soluble trace metals easily get adsorbed in sediments (Mishra and Shukla, 2016).…”