My career in the contaminated land industry started in 1989 with Dames & Moore – there was a time when virtually everyone in the industry seemed to have worked for D&M at one time or another! Like many others in the industry, my background was in other areas (mining environmental, construction supervision but with an unplanned but surprisingly relevant degree in Bio-Resource Engineering from the University of British Columbia). I was hired primarily for my project management and site supervision experience, and after a few months “initiation” putting dirt in jars on the former Mobil Oil Terminal remediation project at Pulpit Point, I moved to Melbourne to manage the Bayside Remediation Project – another former oil terminal. A very quick induction into two of the most significant remediation projects of the day!

While we had some gurus such as Roger Parker and Peter Nadebaum to look up to, we had very little Australian guidance to refer to. ANZECC 1992 Guidelines for the Assessment and Remediation of Contaminated Sites had not yet been developed, the Vic EPA environmental auditor scheme had not started, and we relied heavily on guidelines and procedures developed in the Netherlands and USA EPA, often going back to first-principles. For the Bayside project, our team included hydrogeologists, geotechnical engineers, and a project chemist. We wrote our own D-base programming to manage data, and had our own drafter on site to keep up with the figures. With a sub-contracted mechanical engineer, we even developed and had our own soil-vapour extraction unit with catalytic destruction manufactured for the project! Heady days indeed.

While some aspects of the industry were nascent, others were well developed (based on USA experience), with D&M having a particularly strong OH&S culture. The entire site team had base-line medicals, with one member showing up high blood-lead levels apparently from too much exposure to leaded petrol (from back-yard mechanics - not as a result of remediation or site investigation activities…).

Over the following years, the amount of guidance available for the industry has increased exponentially, with guidelines available or prescribed for almost all aspects of what we do – this has contributed to a much more consistent standard across the practice, but also seems to have taken much of the thought out of the process, except for leading edge specialist applications on the more complex projects. It is harder for the average practitioner to get as involved as was the case in the early days. When Mobil divested their retail outlets across Australia in the early 90’s, we had virtually the entire staff of D&M, including draftsmen, scientists and secretaries, out doing site assessments with shift-teams working into the night with hand-sketches and correction tape to prepare progress reports!

Some aspects have shown significant advancement over the decades, particularly with assessment and management of petroleum hydrocarbons. A sound body of understanding of biodegradation processes has developed in parallel with more sophisticated investigation techniques such as high-resolution vertical profiling and site characterisation using in-situ analytical tools. Monitored natural attenuation and source zone degradation have become more than a “do-nothing” approach. Dig and dump is no longer the default remediation strategy. In other areas, such as management of asbestos, it seems to be one step forward, two steps back, and we struggle to disseminate the understanding of the risks of asbestos in soil that were quite clearly articulated in the enHealth technical monograph “Management of asbestos in a non-occupational environment”, which was published in 2005. The Western Australia Department of Health has been a leading regulator in adopting standard practices for assessment and management of asbestos in soils, but despite adoption of their 2009 guidelines in the NEPM, their 2021 update has not received widespread acceptance by other Australian regulators.

On reflection, the contamination assessment, remediation and management industry has been interesting and rewarding throughout my career, and I am thankful for the hard work of colleagues, regulators and industry organisations in providing conferences and papers for sharing of information and experiences, and encouraging an objective of continual improvement. The pace of change keeps up, with new contaminants and technologies constantly on the horizon, so that the challenge for new starters is in no way diminished from that which we, nearing the end of our careers, can look back on with a certain fondness!

Electrochemical fluorination products (ECF):

PFAS manufactured by ECF, such as sulfonamide linked products almost always show oxidation products dominated by PFAS of corresponding perfluorinated carbon content.

Figure 4: Sulfonamide linked PFAS products

Other PFAS:

Replacement PFAS products including the perfluorinated Gen-X and PFEESA species did not exhibit degradation products included in traditional PFAS analytical suites and hence their presence may have been easily missed under legacy environmental monitoring projects. In contrast, polyfluoroether compounds in which complete substitution with fluorine does not occur (e.g., ADONA) have been reported to degrade under TOP-A conditions by other researchers.

Perfluoroethylcyclohexane sulfonate (PFECHS) belongs in the same chemical class as PFOS although can be distinguished from the better known perfluorinated sulfonic acids (PFSAs) by the presence of a cyclic perfluorinated moiety. Industrially it has been used as an erosion inhibitor in aircraft hydraulic fluid, but its inclusion in PFAS lists is relatively new. Under the experiment PFECHS did not degrade, and as for Gen-X and PFEESA, TOP-A would not have included contributions from PFECHS contamination.

6:2 FTAB has received attention recently due to its inclusion in AFFFs. Although it is a telomer based product and exhibits the characteristic distribution of PFCA products, it is distinctive because it is also a zwitterion.

Figure 6: Gen-X, PFEESA, PFECHS, 6:2 FTAB products
¹Improved Total Oxidizable Precursor Assay for Quantifying Polyfluorinated Compounds Amenable to Oxidative Conversion to Perfluoroalkyl Carboxylic Acids; Katerina Tsou, Edmund Antell, Yanghua Duan, Christopher I. Olivares, Shan Yi, Lisa Alvarez-Cohen, and David L. Sedlak. ACS ES&T Water 2023 3 (9), 2996-3003

ALS Australia’s TOP-A Services:

Since the emergence of PFAS as contaminants of concern, chemists have battled hard to devise analytical solutions. ALS provides analytical services for many of today’s prevailing solutions including TOP-A. Total oxidisable precursor assay is a useful technique, but caution is required with data interpretation. However, despite challenges associated with TOP-A, an understanding of degradation patterning can be helpful rather than hindering, for example, providing a way to infer manufacturing processes and hence PFAS sources (e.g., telomerisation vs ECF). New and emerging enhancements are also frequently being published on optimisation of TOP-A.

ALS Australia offers services for TOP-A in various matrices, and method codes and matrices are summarised below:

Our technical experts and customer services teams are here to discuss your PFAS needs including elucidation of the presence of PFAS ‘dark matter’ and assist with interpretation of TOP-A results as required.

If you have any questions relating to PFAS Screening, please contact:

Brisbane: ALSEnviro.Brisbane@alsglobal.com

Sydney: ALSEnviro.Sydney@alsglobal.com

Melbourne: ALSEnviro.Melbourne@alsglobal.com

Perth: ALSEnviro.Perth@alsglobal.com

- Stephen Bourhill, Ventia Australia Pty Ltd

It is a strategic priority for Energy Resources of Australia (ERA) to comprehensively rehabilitate the Ranger Project Area.

Rehabilitation and closure planning began soon after the Ranger mine began producing uranium oxide in 1981. Mining finished in 2012 and with the completion of ore processing in 2021 the mine transitioned to its final rehabilitation and closure stage. ERA’s focus is to create a positive legacy and achieve world class, sustainable rehabilitation and closure of its former mine assets.

An essential early stage to the successful rehabilitation of the site involved the enhanced consolidation of a 20-90m deep layer of tailings that had been transferred to the former mine pit, Pit 3. To achieve this, the design required over 41,000 Prefabricated Vertical Drains (PVDs) to be installed into the tailings to depths of up to 40 metres. Once installed the PVD would provide a preferential flow path (using capillary action) for water trapped within the tailings, allowing the water to be expressed upward and the tailings to rapidly consolidate. Due to a covering layer of water up to 5 metres in depth over the tailings, a specialised delivery method would be required to achieve the projects aims.

The approach

Ventia was engaged to design, construct and operate a unique barge system to allow the installation of the PVDs from the water’s surface. Working closely with ERA and Ventia’s subcontractors, Ventia designed a barge system that could:

• be easily transported to the remote site,
• be quickly and safely assembled,
• manage the extensive forces applied to it by the two 100 tonne mobile PVD installation rigs,
• included integrated moon pools to allow wicks to be installed from within the barge footprint
• provide all necessary support functions for the works and workforce,
• could be positioned using a highly accurate computer controlled winching system, and;
• anchor the winch wires to specifically installed rock anchors in the pit wall

Safety to the workforce was of paramount importance. The challenging site conditions required a workforce to operate in close quarters to operating plant in a hot, humid tropical environment on an acidic water body. Systems were designed and implemented prior to the commencement of works to allow the workforce to operate safely in the environment and Ventia’s drive towards continuous improvement ensured processes were updated where potential improvements were identified.

The Result

The works required an onsite workforce of over 70 personnel and over 101,000 hours worked on site to successfully deliver the project. Ventia’s Senior SHEQ Engineer, Allan Garland, said the team’s strong commitment to safety ensured the project was completed lost time injury free and demonstrated the value of early innovative design approaches for safety.

In March 2023, Ventia successfully completed the installation of 41,850 PVDs with 1,640,643LM of PVD material installed into the tailings (equating to driving the distance from the mine to Alice Springs NT). And throughout installation, the barge positioning system used 4 winches under 11t of tension each to hold the ±500t barge within an average of 89mm, which was well within the design specification, said Ventia Senior Project Engineer, Stephen Bourhill.

The successful delivery of this project leveraged the innovative skills of the Ventia team to develop a safe and reliable wick installation process. Ongoing survey of the tailings indicate the wicking process has met and exceeded the expectations of ERA’s model and will help ensure the success of future rehabilitation stages, said Ventia Project Manager, Jayson Gaul.

Figure 1: Figure 1: Barge with 2 x PVD Installation Rigs

Figure 2: Drone Photo of the Wicking Barge Operating Deck

Figure 3: A PVD Installation Rig

Figure 4: A rock anchor group, used to anchor the Barge Positioning System

Article Published on 12/12/2023

The statements, analyses, opinions, information and conclusions that may be found in the articles of this publication are those of the author and not of the Australasian Land & Groundwater Association Ltd (ALGA), which only acts in the capacity as publisher. No part of this publication can be regarded as legal advice. Although care has been taken in preparing this publication, neither ALGA nor the author represent or warrant that the information supplied is current, complete or accurate. To the full extent permitted by law, the author and ALGA do not accept any liability, or owe a duty of care, to any person in respect of any such information. No person should rely in any way on the content of this publication and are encouraged to seek independent legal or other professional advice, if required.

As an environmental data expert, can you share your perspective on the remediation field and how your technology can be leveraged to improve the way in which the industry works?

One of the biggest challenges we see across our industry is the retention of environmental monitoring data and access to it. For instance, contractors often share data with multiple stakeholders, whether as part of a joint venture or through engagement with consultants. This ongoing sharing of geological, geotechnical, field and laboratory data between multiple organisations can cause unnecessary delays in project workflows. To further complicate matters, most organisations are not set up for the sharing of site data within a secure cloud-based environment. So, sending data back and forth via spreadsheets or data files can be quite inefficient and time-consuming.

This is where having a secure, cloud-based data management system that is tailored to the needs of our sector can be very beneficial to a project. It means contractors can keep their projects moving by having all their data in one location while also being able to share results across multiple stakeholders as needed.

For example - increasingly, contractors are setting up temporary and project-specific ESdat Online subscriptions specifically to cater to all stakeholders for the duration of a project. Being cloud-based, cost-effective and with no setup time, ESdat Online is ideally suited for this.

Laboratory, field, borehole, geology and logger data can all be stored and accessed from this single point of truth, so all stakeholders can access the data they need. Data can be shared either by providing restricted logins (such as read-only, or to only access certain data), or by integration with tools like Power BI to create dashboards that consolidate ESdat data with other operational or contractual information.

At the end of a project, the data can be downloaded and the account closed so there is no unnecessary ongoing maintenance of the account.

Regulatory compliance is an essential requirement for most projects. How does ESdat support its clients to meet these guidelines?

Our team at ESdat are highly experienced in the environmental industry (having worked in it themselves) and many are Australia-based, giving us a close understanding of the importance and complexities of compliance to local regulations. As part of our software, we have pre-loaded localised regulatory guidelines which automatically provide clients with exceedance notifications. This can be very helpful and supports various stakeholders to manage the requirements needed on a project.

Can you tell us a bit about your company history and the types of projects you are involved with locally?

We started off almost 20 years ago now. While we have expanded our reach to regions like Canada (and have local support set up there), we have our head office based out of Sydney, Australia, which means our clients in Australia and New Zealand are able to access support from experts very familiar with their region and regulations.

The two big sectors we’ve seen growth in this year are mining operations and infrastructure. We are seeing more and more cases where data needs to be consolidated from multiple parties on the ground and made available for corporate reporting. One infrastructure project we are very pleased to be supporting right now is the Sydney Metro Eastern Tunnelling Package. We are very proud to be able to provide local support to this exciting project.

Security is obviously a major concern for organisations using a cloud-based system. Is there anything you can say to people if they have concerns in this area?

We take security very seriously, as we understand it is critical to the trust that organisations place in us. As a cloud-based system, security is a key strength of ESdat compared to traditional onsite systems. We are Microsoft Partners; all of our ESdat systems are hosted on Azure and have all the security checks and systems that come with that. In addition, our software undergoes continuous penetration testing, where our system is continuously assessed for vulnerabilities to new and evolving threats. We also conduct regular independent cybersecurity assessments, with ESdat achieving an A+ score in the latest instance.

Our security systems and processes have also been independently audited – infact, the Information Security Management Systems we have supporting ESdat have been certified against ISO/IEC 27001:2022. ISO 27001 certification means that we have put in place appropriate systems to manage risks related to the security of the data we handle and that these systems respect the best practices and principles enshrined in the ISO27001 International Standards.

Is there anything else you'd like to add to our discussion today?

Thank you very much to ALGA for the opportunity to talk to you today. It's great to see Cronicle dedicate an edition to the role of contractors in the contaminated land and infrastructure sector given the key role they play in working together with so many other parties in the industry.

Article Published on 12/12/2023

The statements, analyses, opinions, information and conclusions that may be found in the articles of this publication are those of the author and not of the Australasian Land & Groundwater Association Ltd (ALGA), which only acts in the capacity as publisher. No part of this publication can be regarded as legal advice. Although care has been taken in preparing this publication, neither ALGA nor the author represent or warrant that the information supplied is current, complete or accurate. To the full extent permitted by law, the author and ALGA do not accept any liability, or owe a duty of care, to any person in respect of any such information. No person should rely in any way on the content of this publication and are encouraged to seek independent legal or other professional advice, if required.