April 2022 – Liberty Industrial’s Principal Environmental Engineer, John Stevanoni presented ‘Bioremediation – From Lab to Project Myth-Busting’ at the first-ever Australasian Land & Groundwater Association (ALGA) Bioremediation Symposium in Mudgee, NSW.
Exploring the important developments in our understanding and application of bioremediation, John navigated through the ‘how’, ‘where’ and ‘why’, while addressing – and busting – known myths, particularly when considering decommissioning heavy industrial sites. The type and level of contamination found on these sites is almost always a great candidate for bioremediation and when executed well, it offers several environmental and economic benefits.
So, is now the time to consider bioremediation? Here’s the 5×5 with John Stevanoni – Five Questions in Five Minutes.
1. Why the necessity to myth-bust?
The need to myth-bust was realised as a result of reading Remediation Action Plans. Often, the understanding of bioremediation was deviating too far from the current science of bioremediation and as a result, myths were propagating that were costing clients and landowners millions more with less desirable and less sustainable outcomes. The perception that bioremediation can’t work needs to be changed and the priority now is to ensure clients and landowners are making informed decisions when it comes to decommissioning heavy industrial sites.
2. What are some of the myths?
There are many! However, the most common ones we come across are:
Myth 1 = “Bioremediation only works when the soil is not ‘too bad’”
Bust: The concentration and types of organic contaminants that can be treated by bioremediation is almost limitless in a well-designed and managed system.
Myth 2 = “Bioremediation only works to a point and leaves a ‘too much’ contamination behind”
Bust: A well-designed system addressing bioavailability will treat to the strictest criteria.
Myth 3 = “A bioremediation trial is needed to prove bioremediation works. If the trial fails, it doesn’t work”
Bust: Often, a failed trial generally means the trial wasn’t well managed. Of course, expectations may not always match reality, but the tens of thousands of projects completed around the world (many in extreme environments) discount the argument that bioremediation simply doesn’t work.
Myth 4 = “Bioremediation takes too long”
Bust: Often it can require no more than a few months of treatment time. For me, this seems sustainable, especially when considering that the environmental consultant has usually spent much longer characterising the site.
3. Detail some of the important developments in bioremediation?
The most important development would be our understanding of enzymes and how surfactants mitigate toxic effects and make the contamination more bioavailable for both bacteria and fungi. Developments in remote monitoring have allowed for real-time monitoring so issues that, in the past, would have reduced the efficacy of bioremediation no longer have such an impact.
4. When it comes to decommissioning heavy industrial sites, what are the benefits of bioremediation?
The type and level of contamination found on heavy industrial sites are almost always a great candidate for bioremediation and when executed well, it offers several environmental and economic benefits.
Fortunately, bioremediation doesn’t require complex or specific plant and equipment. Similarly, it requires low resources (human capital and material) and the set-up and monitoring phase can occur by the same team conducting the ongoing decommissioning works. As bioremediation is low cost and can scale, ‘unexpected finds’ which are common in decommissioning, have little impact on the overall cost and schedule.
5. In summary, why should we choose to bioremediate?
Firstly, when applied and executed correctly – it works!
It’s also cost-effective, sometimes orders of magnitude more cost-effective, and it’s almost always more sustainable, especially when looking at CO2 emissions and comparing it to thermal desorption (the most common alternative).
To date, there have been tens of thousands of successful projects and every week more journal articles are released reaffirming the science of why bioremediation is a sound and reliable choice.