The Department of Defence has experimented with new technology options to remediate PFAS contamination at Defence bases. Defence detailed that it ‘excavated 14,300 tonnes of PFAS contaminated soil’ at RAAF Base Williamtown, and is ‘also operating three groundwater treatment plants, which, to date, have treated over 3.3 billion litres of water.’ Defence also detailed soil-washing trials at RAAF Base Edinburgh.
On 7 December 2020, the Committee heard from companies contracted by Defence: Ventia Utility Services; Emerging Compounds Treatment Technologies, and Synergy Resource Management, about facilities that provided on Defence bases to attempt to remediate PFAS contamination.
The primary methods of remediation discussed were the treatment of contaminated water, including active ‘pump and treat’ solutions and ‘passive’ treatment systems, as well as the ‘washing’ of PFAS-contaminated soil. Water treatment solutions used at Defence bases include wastewater, surface water and groundwater systems.
Work of Ventia Utility Services
Founded in 2015, Ventia Utility Services (Ventia) is a large infrastructure services provider in Australia and New Zealand. The company has developed a technology for the removal of PFAS from soil and, in collaboration with the Department of Defence, has ‘been focused on the remediation of PFAS contamination and the challenge that that brings’.
Ventia advised that there is ‘generally not one silver bullet that will fix the problem [of PFAS], and the risks that PFAS presents to human health and the environment need to be sustainably balanced with a proportionate remediation response.’
Over the past six years, Ventia detailed that it had invested substantially in the development of solutions to remediate and remove PFAS from the environment. This includes ‘the development and application of thermal technology to destroy PFAS compounds’, as well as ‘SourceZone, Ventia's unique PFAS removal process’.
Ventia described SourceZone as a permanent and complete solution to PFAS soil contamination. This type of technology is colloquially known as ‘soil washing’.
SourceZone treatment at RAAF Base Edinburgh
Since 2018, Ventia has worked with the Department of Defence to trial their SourceZone technology at scale. This trial took place at RAAF Base Edinburgh in South Australia. While acknowledging that ‘all remediation solutions have their place, depending on the challenges and objectives of each individual project’, Ventia’s focus has been on ‘technologies that treat the high-concentration source areas.’ This is based on the fact that ‘up to 90 or 99 per cent of the PFAS mass can remain in soil source areas decades after being deposited’ and that the ‘small amounts of PFAS that continue to leach from these source areas can cause significant issues in groundwater and surface water’.
Ventia described that technologies focused on the remediation of high-concentration source areas are more cost-effective than alternatives and that ‘by removing the ongoing source of PFAS, you are addressing the source, pathway and receptor model. As a result, the source of the PFAS problem can now be dealt with and not left for future generations to fix.’
According to Ventia, SourceZone is ‘markedly different from traditional soil washing, and permanently removes up to 99% of PFAS contamination from soil’. The process involves:
excavation and stockpiling of soil from the contaminated soil source area;
sampling and testing of the stockpiled soil to assess PFAS levels;
feeding of contaminated soil into SourceZone using an excavator or loader;
soil is transported via a conveyor to the first wet process within SourceZone;
soil is sprayed with a wash solution to start the process of removing PFAS;
soil is then exposed to many individual processes, depending on the size and density of the soil particles, to enhance desorption of PFAS;
washed soil is then dried and stored in bunkers for further sampling and testing;
following confirmation of results, the soil is collected by an excavator or loader and reused as backfill within the excavation; [and]
finally, the wash solution is cleaned to be reused again to wash further soil.
With regard to communities affected by PFAS contamination, Ventia noted the industry is ‘very focused on bringing solutions to bear to those challenges faced by those communities’ and that Australia is ‘probably leading the world in many regards with our approaches’ to PFAS management.
Work of Emerging Compounds Treatment Technologies
Emerging Compounds Treatment Technologies (ECT2) advised that it was founded in the United States of America, and that it began researching and developing methods to remove PFAS from water in 2015. In 2017, the company established their first treatment system at RAAF Base Williamtown.
As of December 2020, ECT2 has ‘treated over four billion litres of contaminated water in Australia alone, removing an estimated 35 kilograms of PFAS from the environment.’ The treatment of this affected water has ‘generated a total of 46 tonnes of waste that has had to be disposed of to landfill or thermal destruction, which equates to 0.0025 per cent of waste per litre of water treated.’
Water treatment at Defence bases
As at 30 July 2020, ECT2 operated the following water treatment systems for the Department of Defence:
Williamtown Fire Training Area PFAS source area remediation;
Williamtown Southern Area PFAS plume control;
Williamtown Moors Drain stormwater treatment for PFAS removal;
Williamtown Regeneration Plant that services regenerable ion exchange resin vessels from the three Williamtown sites;
Oakey Former Fire Station PFAS mass removal;
Tindal Fire Training Area PFAS source area remediation;
Tindal Fire Station Area PFAS mass removal; [and]
Tindal Regeneration Plant services regenerable ion exchange resin vessels from the two Tindal sites.
Following a detailed environmental investigation at RAAF Base Williamtown, the Department of Defence identified the former fire training area as a key source area for PFAS contamination. ECT2 were engaged to build a water treatment plant, which began operation in July 2018.
To treat PFAS-contaminated water, ECT2 uses an ion exchange treatment solution, which is a ‘regenerable medium’ that can be reused. Ion exchange resins were selected following laboratory tests which ‘identified that certain ion exchange resins had the highest PFAS removal capacities’. The system at RAAF Base Williamtown utilises three water treatment plants, with a total capacity of 30 litres per second.
Throughout its inquiries into PFAS contamination and remediation, the Committee has received evidence from members of the local community on the impact of PFAS-contaminated water flowing from RAAF Base Williamtown. It was therefore important to hear from ECT2 that their contract with the Department of Defence was 'focused on an off-base plume’ of PFAS contaminated water and that, despite some challenges with landholder agreements, there is a treatment plant at RAAF Base Williamtown ‘that is treating water from the boundary of the property.’
Since 2017, ECT2 has also been operating a water treatment plan at the former fire station at the Army Aviation Centre in Oakey. This plant is ‘treating contaminated groundwater and reinjecting the treated water back into the aquifer to remove PFAS from the environment.’ ECT2 advised Oakey water treatment plant also uses a regenerable resin system, and has ‘has treated over 122 million litres of PFAS contaminated water, while only generating 800kg of waste.’
ECT2 detailed that its treatment process enables the company to ‘effectively superload that PFAS concentrate down to very small volumes’ resulting in minimised amounts of waste. The waste produced by the treatment process is assessed, and any hazardous waste is sent to a facility in Melbourne for thermal destruction, which requires temperatures of between 900 and 1,100 degrees centigrade.
ECT2 also outlined efficiency improvements it had made to its technology at RAAF Base Williamtown. The waste produced by this system has reduced from one per cent per litre of water treated, to 0.1 per cent.
While discussing improvements to PFAS remediation at sites using ‘pump and treat’ technologies, ECT2 stated that ‘beyond the development of new treatment technologies, the best opportunities to improve remediation … are to proactively assess and manage the site hydrogeology to ensure the most is made of every well installed and litre pumped.’ This may include adding more wells where PFAS concentrations are highest, evaluating ways to enhance groundwater extraction, and testing the addition of infiltration galleries, recharge fields or recharge trenches to increase PFAS removal rates.
Work of Synergy Resource Management
Synergy Resource Management (Synergy) is an Australian company specialising in civil construction, demolition and environmental contamination remediation. This includes a ‘a very large focus on research and development in remediation and treatment technologies’. As at December 2020, Synergy has treated ‘over three billion litres of PFAS contaminated water.’
In 2015, following an approach from the Department of Defence, Synergy established a large-scale water treatment plant at RAAF Base Williamtown. The Committee heard Synergy has also established water treatment systems at other Defence sites, including Jervis Bay, HMAS Cerberus, and RAAF Base Tindal, where Synergy ‘treated highly contaminated [Aqueous Film Forming Foam] wash water that was produced from testing the fire suppression system.’
PFAS treatment at RAAF Base Williamtown
The first water treatment plant built by Synergy at RAAF Base Williamtown operated for three years and ‘was a combination of anion exchange … and activated carbon’. This ‘blend of two technologies’ was ‘an Australian-first high-flow-rate system to treat PFAS and the other co-contaminants on site’ and treated approximately 1.8 billion litres of PFAS-contaminated water. Over its operating life, the Synergy plant at RAAF Base Williamtown removed over 14 kilograms of PFAS from the environment.
Synergy highlighted the lessons learnt operating the treatment plant at RAAF Base Williamtown:
When treating construction and environmental water that have high levels of solids, organics and tannins an emphasis is placed on the importance of pre-treatment. This includes powdered activated carbon injection and settlement prior to the specialised media filtration downstream to optimise the filtration use, ensuring longevity and lessening the need to change the media out.
Lake Cochran water treatment technologies
Synergy was also engaged by the Department of Defence to establish a second water treatment plant at RAAF Base Williamtown. This plant, which is focused on the Lake Cochran outflow, aimed ‘to mitigate the risk of water flowing offsite by both creating freeboard in the lake and reducing the level of PFAS within the lake.’
This plant serviced Lake Cochran from 2016 until August 2020, and treated 1.17 billion litres of water. In August 2020, it was replaced by a new ‘passive barrier system’ which is intended to ‘passively remove PFAS from the water that moves through that system to reduce both the concentration of PFAS within the lake and the concentration of PFAS moving offsite.’
Synergy explained the newer passive barrier system is installed ‘in both the incoming drains in Lake Cochran and the outgoing drain’ and includes ‘three passive filtration walls, as well as a weir box system, which is a polishing stage for PFAS removal, and also a geoweb filtration system which is suited to low-lying drains.’
As one reason for the trial of the new passive system at RAAF Base Williamtown, Synergy stated that the Department of Defence has ‘always wanted to explore through Australian and overseas suppliers improvements to technologies, new technologies, and also lower cost’. Synergy explained passive treatment of contaminated water ‘is a much lower cost, lower waste and easier to implement and maintain system than active pump and treat water treatment plants.’
Synergy advised that the original Lake Cochran water treatment plant cost up to $500,000 per month to operate. In comparison, the new passive barrier treatment system, while slower, costs ‘around $20,000 to $30,000 a month’.
While discussing their engagement by the Department of Defence to address PFAS contamination at Lake Cochran, Synergy noted that their system was required to ‘treat the water that was leaving that lake’ and did not extend to work to address ‘anything in terms of stopping the groundwater from entering the lake or any sort of modifications to the lake itself.’ Mr Reardon, Chief Executive Officer at Synergy, noted contractors are:
… usually given a scope of work developed by Defence and their consultants. We don't make the decisions on whether to treat onsite or offsite. We're not part of that decision-making process. We're contractors who come in and are told, 'This is the scope. This is what we want you to do,' and then we use our smarts to design and develop technologies around that specific area or zone of influence.
Reflections on the PFAS National Environmental Management Plan (NEMP)
As discussed in the previous two progress reports and in Chapter 4, the Committee has received evidence about the Australian Government’s process for revising to the PFAS National Environmental Management Plan (NEMP). Version 2 of the PFAS NEMP was published in May 2020.
When queried on the PFAS NEMP and the interface between federal, state and territory governments, Ventia stated ‘having national guidance is helpful and it's definitely heading in the right direction.’ Mr Grimson, PFAS Manager, Ventia was also positive about the process for the next iteration of the NEMP, noting:
The engagement moving to a NEMP 3.0 has been really good. They're communicating well and bringing up issues at the back of the NEMP 2.0. They raise a number of issues that'll be fixed in 3.0, and I think they're all relevant and worthy to be in there.
However, Ventia described the challenges faced in the management of PFAS contamination, due to coordination issues across federal, state and territory governments. Ventia advised ‘there is landfill guidance in the NEMP at a national level, but [Ventia is] not seeing that adopted in the various states, at least from a practical level.’
Mr Andrew Reardon, the Chief Executive Officer of Synergy Resource Management offered a similar view regarding the management of PFAS waste, stating:
My personal experience is that it's still very disjointed across all the states and territories in this country. We've worked in every one of them except for Western Australia. There are different perceptions of what you should treat water and soil to on site and there's not consensus across states and territories. We hope that the new NEMP will help with that regard to actually help contractors execute the works.
All three companies agreed on the need for nationally consistent PFAS regulation and standards. Synergy advised that, in terms of acceptable PFAS levels:
In Australia, even with what we've seen with NEMP 2.0, it could depend on one person or a couple of people at a regulatory level who might decide to go higher or lower.
ECT2 cautioned about the potential for projects to ‘get bogged down with the regulation’. Mr Carl Sueli, ECT2’s General Manager in Australia, argued that very low limits could potentially reduce other remediation opportunities.
Synergy also highlighted one of the benefits that nationally consistent PFAS standards would bring to the marketplace:
As an industry, we're still evolving, and we just need some support with the regulators to make regulatory data more consistent. It will enable our clients, including Defence, to have a clearer path as to what the remediation objectives should be so that they can go to market and get a good consistent apples-for-apples comparison.
Reflections on health-based guidance values for PFAS
The Committee also heard from ECT2 on international comparisons with Australia’s health-based guidance values for PFAS. The Australian guidelines, recommended by Food Standards Australia New Zealand, are discussed in Chapter 6.
ECT2 noted that tolerable daily limit guidelines are ‘based on a toxicology focus’ and that ‘each country and even regions within countries have different toxicologists, and they all have different interpretations of the science because it's far from an exact science’.
Discussing variations in global intake standards, ECT2 stated:
For example, in the United States we're seeing some states where these regulations and/or guidelines that are being set are below those seen in Australia, and in other states they're similar or they're higher. In Europe the regulations and guidelines vary greatly, as does the interpretation of the toxicology.
Somewhat in contrast to the identified need for a nationally consistent approach for standards, ECT2 explained that in addition to toxicology standards, environmental and other factors also contribute to how PFAS contamination is managed across the world:
A lot of it depends on the environment local to the country or the region. Is it landlocked or is it predominantly near a marine environment? What are the local culture and habits? What types of food do people eat? Where do they source these foods? How do they use water for recreational activities? So a lot of factors come into the decision-making process, not the least of which is the toxicological interpretation. And political pressure also comes into play—in a big way in some cases.
Need for more research into PFAS remediation
The Committee heard about the importance of continued research into PFAS remediation technologies. These includes not only the soil- and water-contamination solutions outlined in this chapter, but also further research into other in-situ systems, as well as technologies to safely destroy PFAS.
In its submission, Ventia acknowledged there ‘are still significant gaps in knowledge in keys areas such as human health toxicology, PFAS behaviour in the environment and remediation of PFAS in soil and water’ and stated:
This presents many challenges to an industry that is trying to manage and remediate the PFAS problem now before key fundamental knowledge has been developed. To undertake a successful PFAS remediation project therefore a significant focus on research is required.
Ventia supported two of the projects selected for the Australian Research Council’s PFAS Remediation Research Program:
University of Queensland project, led by Professor Jochen Mueller, on the remediation of PFAS contaminated soil using soil washing and immobilization.
University of Newcastle, in partnership with Suez and Ventia joint venture, led by Professor’s Eric Kennedy and Michael Stockenhuber, on the thermal decomposition of PFAS.
Further information on these research projects is at Chapter 9.
ECT2 advised it also conducts research into PFAS and other contaminants. The company describes its focus as:
[ECT2] focus solely on water and we limit our focus to remediation of emerging and complex-to-treat contaminants … The specialised focus means that we are continuously scanning the horizon to identify emerging contaminants of concern and with a view to removing those contaminants from water to protect human health and the environment.
In its submission to this inquiry, ECT2 stated that PFAS remediation efforts will improve with the development of ‘in-situ soil and water treatment, destruction, and immobilisation technologies’ and that ‘in-situ destruction technologies will provide the greatest return on-investment and greatest liability reduction.’
Synergy also described itself as having a ‘large focus on research and development in remediation and treatment technologies’ and has ‘environmental scientists, chemists and engineers that work in collaboration with the Queensland University of Technology to test and design new remediation techniques and strategies.’
Much of the Government’s response to PFAS has been predicated on the precautionary principle: that the lack of full scientific certainty should not be used as a reason for postponing a measure to prevent degradation of the environment where there are threats of serious or irreversible environmental damage.
While there are many unknowns about the environmental and human health impacts of PFAS contamination, there are also many unknowns about the ability to fully remove and restore the environment to its original condition.
The Committee notes the innovative approaches that have been trialled at Defence bases. These approaches span from remediation of the soil, wastewater, surface water and groundwater.
The Committee also acknowledges evidence that the development of these remediation technologies benefited from expertise that contracted service providers drew from around the world, and also contributed to the scientific knowledge base on the treatment of PFAS contaminants.
The Committee notes the industry has committed to ongoing research into PFAS remediation, immobilisation and destruction, and that much of this research is being done in partnership with Australian universities.
The Committee considers that these technologies provide optimism that remediation is possible, and encourages further development and experimentation of the science and technology to progress remediation efforts.
The Committee notes the challenges faced by remediation technology operators due to ‘disjointed’ standards. The Committee also heard the positive feedback on the consultation process for NEMP 3.0, and that these concerns may be addressed through the next revision.
The Committee acknowledges evidence that further development and progress in in-situ remediation solutions would benefit from nationally consistent standards, allowing easier comparison of data obtained from various sites.
However, the Committee acknowledges evidence that standards should allow for local factors to be accommodated when assessing the appropriateness of a remediation method.