East, K, Maier, A & Gimber, C 2022, 'Consideration of the risks per-fluoroalkyl and poly-fluoroalkyl substances pose in adopting suitable mine closure rehabilitation milestones and completion criteria', in AB Fourie, M Tibbett & G Boggs (eds), Mine Closure 2022: 15th International Conference on Mine Closure
, Australian Centre for Geomechanics, Perth, pp. 439-448, https://doi.org/10.36487/ACG_repo/2215_30
There are a number of activities associated with mining operations that may result in release of a range of constituents of potential concern (COPCs) into the environment. However, impacts associated with per- and poly-fluoroalkyl substances (PFAS) have the potential to require investigations (and potentially remediation) with cost, time and reputation implications over and above ‘conventional’ contaminants, due to the nature and behaviour of PFAS. These manufactured chemicals are known to be persistent in the environment, bioaccumulative in organisms and toxic at relatively low concentrations (PBT). As COPCs are most commonly discussed in relation to fire training activities at defence facilities and airports, the risks and liabilities to mine operators from PFAS related issues are not fully understood or adequately quantified. Undertaking environmental due diligence audits of mine operations (as the first stage of assessment) will provide a sound basis to develop a conceptual site model (CSM), in turn enabling order of magnitude (OoM) provisioning and scheduling in order to plan for any remedial and management measures associated with PFAS.
Given the PBT nature of PFAS and the disturbed hydrogeological and hydrological systems associated with mine sites, there are potential risks to air, water and soil quality (and therefore rehabilitation success) that, if not better understood, may limit the practical adoption of appropriate remediation and monitoring measures to achieve relinquishment. Such risks include long-term uncertainty in water quality projections, particularly if a mining void is left as a permanent sink for groundwater or if the site is near a sensitive receiving environment. The implications this may have on setting reasonable and effective rehabilitation milestones and completion criteria are not fully understood, and if not appropriately considered, may also limit the assessment of reasonable residual risk posed.
Key aspects to be discussed include (1) why the presence of PFAS (compared with ‘conventional’ contaminants) may require longer-term planning; (2) what are the long-term risks PFAS poses in terms of achieving relinquishment/accepted post-mining land-use (PMLU); (3) how can these risks be appropriately managed, including a proposed framework for creating appropriate rehabilitation milestones and completion criteria in terms of PFAS; and (4) implications for capturing sufficient closure provisioning based on the unique requirements for PFAS investigations, waste management and remediation.
Keywords: per-fluoroalkyl and poly-fluoroalkyl substances, contaminated land, remediation, mine closure planning
Aminot, Y, Sayfritz, SJ, Thomas K.V, Godinho, L, Botteo,n E, Ferrari, F, Boti, V, Albanis, T, Köck-Schulmeyer, M, Diaz-Cruz, MS, Farré, M, Barceló, D, Marques, A & Readman, JW 2019, ‘Environmental risks associated with contaminants of legacy and emerging concern at European aquaculture areas’, Environmental Pollution, vol. 252, part b, pp. 1301–1310,
ANZG 2018, Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Governments, and Australian State and Territory Governments.
ASC NEPM 1999, National Environment Protection (Assessment of Site Contamination) Measure 1999, amended 2013, Australian Government, Canberra.
ATSDR 2020, Per- and Polyfluoroalkyl Substances and Your Health: Health Effects of PFAS, Agency for Toxic Substances and Disease Registry, Atlanta.
Australian Government 2019, Industrial Chemicals Act 2019.
Bennett, K 2016, ‘Abandoned mines — environmental, social and economic challenges’, in AB Fourie & M Tibbett (eds), Mine Closure 2016: Proceedings of the 11th International Conference on Mine Closure, Australian Centre for Geomechanics, Perth,
Concawe 2016, Environmental Fate and Effects of Poly- and Perfluoroalkyl Substances (PFAS), Brussels.
CRC CARE 2016, A Human Health Review of PFOS and PFOA, technical report no. 42, The Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Newcastle.
EEA 2017, The Arctic Environment, European Perspectives on a Changing Arctic, publication no 7, European Environment Agency.
Eschauzier, C, Beerendonk, E, Scholte-Veenendaal, P & de Voogt, Pim 2012, ‘Impact of treatment processes on the removal of perfluoroalkyl acids from the drinking water production chain’, Environmental Science and Technology, vol. 46, no. 3, pp. 1708–1715.
Gebbink, WA, van Asseldonk, L & van Leeuwen, SPJ 2017, ‘Presence of emerging per- and polyfluoroalkyl substances (PFASs) in river and drinking water near a fluorochemical production plant in the Netherlands’, Environmental Science & Technology, vol. 51, no. 19, pp. 11057–11065.
Ghisi, R, Vamerali, T & Manzetti, S 2019, ‘Accumulation of perfluorinated alkyl substances (PFAS) in agricultural plants: a review’, Environmental Research, vol. 169, pp. 326–341.
Grandjean, P, Heilmann, C, Weihe, P, Nielsen, F, Mogensen, UB, Timmermann, A & Budtz-Jørgensen, E 2017, ‘Estimated exposures to perfluorinated compounds in infancy predict attenuated vaccine antibody concentrations at age 5-years’, Journal of Immunotoxicology, vol. 14, no. 1, pp. 188–195.
HEPA 2020, PFAS National Environmental Management Plan Version 2.0, Heads of EPA Australia and New Zealand.
Howard, PH (ed.) 1991, Environmental Degradation Rates, CRC Press, Boca Raton.
ITRC 2021, ‘Physical and chemical property values for selected PFAS’, PFAS Technical and Regulatory Guidance Document and Fact Sheets, Interstate Technology & Regulatory Council, PFAS Team, PFAS-1, Washington DC,
Kurwadkar, S, Dane, J, Kanel, SR, Nadagouda, MN, Cawdrey, RW, Ambade, B, Struckhoff, GC & Wilkin, R 2021, ‘Per-and polyfluoroalkyl substances in water and wastewater: a critical review of their global occurrence and distribution’, Science of the Total Environment, vol. 809,
Looker, C, Luster, MI, Calafat, AM, Johnson, VJ, Burleson, GR, Burleson, GF & Fletcher, T 2014, ‘Influenza vaccine response in adults exposed to perfluorooctanoate and perfluorooctanesulfonate’, Toxicological Sciences, vol. 138, no. 1, pp. 76–88.
May, WE, Wasik, ST, Miller, MM, Tewari, YB, Brown-Thomas, JM & Goldberg, RN 1983, ‘Solution thermodynamics of some slightly soluble hydrocarbons in water’, Journal of Physical and Chemical Reference Data, vol. 28, pp. 197–200.
Mei, W, Sun, H, Song, M, Jiag, L, Li, Y, Lu, W, Ying, G-G, Luo, C & Zhang, G 2021, ‘Per- and polyfluoroalkyl substances (PFASs) in the soil–plant system: sorption, root uptake, and translocation’, Environment International, vol. 156, 106642,
Newell, CJ, Adamson, DT, Kulkarni, PR, Nzeribe, BN & Stroo, H 2020, ‘Comparing PFAS to other groundwater contaminants: Implications for remediation, Remediation, vol. 30, pp. 7–26.
NTP 2016, Immunotoxicity Associated with Exposure to Perfluorooctanoic Acid and Perfluorooctane Sulfonate, National Toxicology Program, Research Triangle.
Rangaswami, O 2022, CERCLA Liability for PFAS Contamination on Track to Begin in 2023, Taft Stettinius and Hollister LLP,
Rotterdam Convention 1998, Rotterdam Convention on the Prior Informed Consent Procedure for Certain Hazardous Chemicals and Pesticides in International Trade, United Nations Treaty.
Secretariat of the Basel, Rotterdam and Stockholm Conventions 2020, UN Experts Recommend Listing Hazardous Industrial Chemicals DecaBDEand PFOA, press release 11 September 2020.
Sun, M, Arevalo, E, Strynar, M, Lindstrom, A, Richardson, M, Kearns, Pickett, A, Smith, C & Knappe, DRU 2016, ‘Legacy and emerging perfluoroalkyl substances are important drinking water contaminants in the Cape Fear river watershed of North Carolina’, Environmental Science & Technology Letters, vol. 3, no. 12, pp. 415–419.
USEPA 2018, Long-Chain Perfluoroalkyl Carboxylate and Perfluoroalkyl Sulfonate Chemical Substances; Significant New Use Rule, United States Environmental Protection Agency, Washington DC,
USEPA 2022, Our Current Understanding of the Human Health and Environmental Risks of PFAS, United States Environmental Protection Agency, Washington DC.