Exploring coal ash repository solutions for management and compliance: insights from Dr Sarah Groves

Dr Sarah Groves

Dr Sarah Groves is a Principal Hydrogeologist based in our Sydney office. With over 20 years’ experience in hydro geochemistry and environmental science, Sarah has worked with government and commercial clients to provide environmental assessments and approvals, planning, environmental management, and compliance.

Sarah’s technical expertise provides her with a unique perspective on large-scale water resources projects, in particular where there is a risk of impact to groundwater. Sarah has a PhD and Bachelor of Science from the University of New South Wales, and a Bachelor of Applied Science (Geology) from University of Technology, Sydney.

Here Sarah discusses the challenges facing operators and how an integrated approach is needed to address the management and compliance of these complex sites.

What are some of the challenges that face managers of coal ash repositories?

As in many industries, compliance and economics are driving change.  Management of coal ash repositories can be complex. They often have decades of deposited ash stored in ash dams that spread over large areas. Successful and safe management of these repositories requires a number of questions to be answered such as:

i) how do I manage the quality of surface and groundwater on site and the discharge that flows to regional waterways and aquifers,

ii) will I comply with Environment Protection Authority (EPA) regulations and the sites Environmental Protection Licence (EPL),

iii)  can I use geotechnical solutions to help with compliance and management,

iv) what are the long-term implications of coal ash storage, and finally

v) how do I work towards a remediation and closure strategy?

The progression through a sustainable coal ash management strategy takes time, and operators should look to experts to help with adopting an integrated approach with the aim to implement innovative measures where possible.

What drivers are affecting the way coal ash is managed in Australia and New Zealand?

Governments are now realising that coal ash repositories and their remediation will be a costly undertaking. An example is in 2021 the NSW public works committee published a report investigating the cost of remediating coal ash repositories. One of the recommendations from this report was for the NSW EPA to notify all ash repositories in NSW to undertake a Pollution Reduction Study (PRS) and form a Pollution Reduction Plan (PRP). Failure to comply with the PRP (in an agreed timeframe) is an offence and further regulatory or enforcement action may be undertaken.

What opportunities do you see for managers to address changes in coal ash repositories management?

Comprehensive management of coal ash repositories is now mandatory with large fines for non-compliance being enforceable. Managers of these and other similar waste repositories can be on the front foot with government regulators by understanding the types of information they need to supply for compliance of EPL’s and PRS’s. Targeted monitoring can improve efficiency in managing the site as well as substantial and ongoing monetary savings.

Assistance from consultants who have “been there, done that” can help with following a direct path to compliance, ensuring that regulations are properly followed as well as providing novel solutions for management and possible value add solutions (such as finding useful and commercial applications for waste material).

How is Tetra Tech responding to these changes and clients’ needs?

Choosing the most effective management solution for operators is unique to each site with varying operational, economic, and environmental challenges. Tetra Tech Coffey’ s outstanding team of scientists and engineers have helped clients navigate these complex environmental challenges to arrive at solutions that meet their unique needs.

Our strength is the diversity of our project portfolio and the depth of our in-house talent, allowing us to draw upon expertise from our groundwater, geotechnical, contaminated land, and rehabilitation teams.

Our teams also include specialists who have worked for commercial operators, and government regulators, allowing us to create simple and efficient interfaces between clients’ needs and government compliance.

Tetra Tech Coffey has in-house capabilities for implementing advances in automatic reporting techniques – such as creating dash boards with real-time monitoring data to better help our clients manage their sites with faster reaction times if there is a potential problem with movement of contamination.

What is on the horizon for how we manage coal ash repositories?

New ways of managing these sorts of sites such as:

  • the use of automated data collection systems using digital data loggers, telemetry and dashboards containing real time information about water levels, runoff, water chemistry (and whether they are about to exceed guidelines and trigger values).
  • use of tracers to define various aquifers the runoff is discharging (deep, perched, regional).
  • Biological, geochemical and geotechnical solutions to reduce the concentrations and movement of accumulated elements in the stored material.

 Connect with Sarah at [email protected]

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