Treating PFAS – Passively!

Treating PFAS – Passively!

PFAS – What is it?

PFAS (pifaas) stands for per- and poly-fluoroalkyl substances. These substances are a group of thousands of man-made chemicals that possess several unique properties and have a fascinating history.

These chemicals are stable, resistant to water and oil, stain resistant, have surfactant behaviours and are heat-proof. These qualities make them particularly useful in a lot of products – non-stick cookware, water-repellent clothing, stain resistant fabrics, fire-fighting foams and even cosmetics.

Apart from these unique qualities, PFAS also have an interesting history. Apparently, they were more an accident than a discovery – or an accidental discovery by scientists back in 1938.

With their unique and desirable qualities that has led to the development of innovative products, why is it that we should be concerned about PFAS?

Causes for concern

PFAS contain extraordinarily strong (carbon-fluorine) bonds making it resistant to degradation. This means that these chemicals can hang around for an exceptionally long time, giving them the term – ‘forever chemicals’.

This long-lasting and highly mobile nature of PFAS chemicals causes them to accumulate in the environment and naturally pass on to humans, animals and plants. While research into the side-effects of exposure to PFAS is ongoing, it is known that there may be significant adverse health effects to humans, including increased risk of some cancers.

With limited knowledge of the negative impacts of PFAS on living organisms in the past, the use of these chemicals were widespread, and consequently, the contamination caused by it on sites across Australia is extensive.

Contaminating the environment

A major pathway for per- and poly-fluoroalkyl substances (PFAS) to find their way into the environment was through firefighting foams. These foams were sprayed on fires (both real and training) where they were washed in to drains and into the surrounding environment. This not only caused localised hot spots of contamination, but also widespread areas due to the extremely mobile and persistent nature of PFAS chemicals.

Despite the ban on the use of PFAS chemicals in Australia between 2009 and 2019, these chemicals continue to migrate from the source zones via both surface and ground waters.

Overland flow from these areas (rainfall and intercepted groundwater) enters a site’s drainage network and often finds its way to a site’s boundary, potentially affecting downstream ecosystems and communities. This is a long term, continuous problem, if left untreated.

Our solution

We have unrivalled experience in PFAS treatment and have a range of solutions to address various concerns.

Adding on to our extensive range, Enviropacific has come up with a patent-pending design – EnviroPass® – to manage PFAS impacted surface waters through passive, low maintenance means. The system is designed to treat variable runoff from large areas and is a high-flow, low operational-cost alternative to a typical mechanical water treatment system.

Our system is equipped to handle suspended solids often present in surface runoff, uses gravity to pass through cascading adsorption chambers and can easily be scaled up or down to adjust to varying catchment sizes, existing contamination levels, discharge requirements and obligatory treatment timeframes. It’s been designed to specifically address these shortfalls that exist in the market.

Major components

EnviroPass® is suited to any place where offsite PFAS migration is a problem and consists typically of three major components.

  1. Stormwater Interception Point – utilises a weir-based system with offtake orifice to limit flows to designed capacity while maintaining a designated high flow bypass pathway for extreme weather events.

  2. Pre-filter/Sediment Removal Device – removes sediment and debris from the contaminated surface water, allowing optimal performance of adsorption media to be maintained downstream. It is designed to handle large flows with high sediment removal whilst allowing easy maintenance of the system.

  3. Adsorption Media Chambers – designed to allow surface water to flow passively through the system with filter media specifically chosen to accommodate high flows and remain unaffected by any residual suspended solids passing through the system. The cascading bed design used minimises ongoing operational costs by allowing the removal of fully depleted carbon media beds in stages, rather than large and costly replacement of partially depleted carbon.

Our system size is customisable, with adjustment of dimensions made to suit site-specific requirements. Easy maintenance, replacement of media and sampling is also made possible with custom check-plate pit covers which are easily removable by hand.

Benefits of our system

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Enviropacific is delighted to work with the University of Adelaide to enhance our DeFAS® technology, a product of extensive research and development.
Enviropacific’s DeFAS® technology is the culmination of years of research and development, enabling us to provide our clients with a reliable and cost-effective solution for PFAS...