As Technical Director Charles Grimison and Environmental Monitoring Manager Mark Pickles explain, as more is learned about these new contaminants, Ventia is developing innovative technology that could improve PFAS remediation well into the future.
PFAS, known as per- and poly-fluoroalkyl substances, are a diverse group of synthetically produced chemicals resistant to heat, water, and oils. Since the 1970s, PFAS has been used in firefighting foam, industrial applications, and everyday household products.
PFAS do not break down or degrade in the environment. They are soluble, mobile, and can be found in soil, surface water and groundwater.
PFAS contamination in soils and water is well documented, and laboratories have developed an accurate analysis methodology to test for low PFAS concentrations. There are several high-risk sites where PFAS concentrations in soils may be high due to historical PFAS applications. Rainfall events can increase the risk of PFAS running into surrounding waterways. Waterways must be sampled during rainfall events to determine correlations between flows and PFAS contamination load.
Ventia has a specialised team studying and developing innovative technologies to remediate contaminated soils, including those contaminated with PFAS and other forever chemicals across sediment, concrete, and water.
One of the biggest challenges in sampling PFAS is that there can be large volumes of contaminated soil and water with a low concentration of PFAS and small volumes with a high concentration of PFAS. Separating these soils requires different tools, partly due to the varying properties of soil but also due to the varying properties of the PFAS compounds themselves.
“Typically, we would use two or three technologies to clean up a contaminated site… more if water is included,” said Charles Grimison who is the Technical Director for Ventia’s Environmental Services team.
There is also an evolving landscape around the guidelines and criteria because it is a relatively new contaminant. We are still dealing with these changes
It’s important to note that there is currently only one way to properly detect PFAS in water – to get a sample and send it to a laboratory. It is much easier to detect other contaminants. Developing tools to capture a representative sample during periods of infrequent, then heavy, rain is challenging.
This is where Ventia’s new technology is coming into play. It provides automated PFAS sampling systems for capturing samples during rainfall events. Users can configure and control sampling programs using standard wastewater samplers and control instrumentation through a simple SMS control system. It’s part of the first flush, a phenomenon where a larger concentration or mass of contaminants is associated with the initial stages of a storm event compared to the rest of the event.
“Ventia provides networks of monitoring instrumentation,” said Mark Pickles who manages the Ventia Environmental Monitoring team.
“What would usually happen in the field is identifying where PFAS is, looking at the first flush event, and capturing data on the water coming through the system. That’s why we put automated instruments in the field – to accurately sample and monitor that event. We can then accurately measure the mass and concentration of the contaminants.”
It's not just about determining how much PFAS is being detected. It is also about where it is being detected and in what concentrations. This comes from measuring a site's mass flux, which is the mass of a contaminant moving through a specific cross-sectional area.
“We look at the mass and the concentration,” said Charles.
If you have five micrograms per litre of PFAS in one drain compared to 30 micrograms in another, the instinct would be to deal with the 30 milligrams first. However, understanding the concentration of PFAS and the water flow might create a different outcome.
“There may be a greater PFAS mass being discharged via the five microgram per litre drain. That’s why you have to look at both measures to get a better picture.”
One of the challenges for any water utility is being able to collect and interpret data by large teams across multiple offices for several clients. That’s particularly true for any utility working in regional Australia. The focus then turns to the most efficient way to capture that data and feed it back to the customers.
About 10 years ago, Ventia started developing field apps that supported multiple field functions to capture and host data. However, the desire to improve and innovate led to creating a route optimisation web-based program to map out its sampling programs.
“This enabled us to greatly optimise our field schedules and provided a direct link between the planning and implementation phases,” Pickles said.
All Ventia apps are designed to capture data quickly and efficiently. This includes Safety, Health, Environment, and Quality (SHEQ) information, field measurements, data issues, photos, and verification systems.
The Ventia teams also have access to historical datasets against which to validate new readings. The apps can notify clients immediately of any reportable observations.
“For example, if there were a potential petrol leak in a retail service station, an email would go straight to the client advising of this,” Pickles said. “The same goes for other contaminants in other locations.”
All that data is instantly captured and stored within a secure database. This allows Ventia to add additional functionality as requested by the client, who can access and download that data when needed.
Since 2012, Ventia has captured more than 170,000 measurements and 135,000 photos. This has eliminated the need for paper-based field sheets, increasing accuracy and transparency. That increased accuracy is derived from the automated validations that can occur with the field scientists still on site, so there is less need to revisit sites in a short period. This increases the sustainability outcomes, as there are fewer rollouts of staff and vehicles, along with the elimination of printing paper field sheets.
When talking about accuracy, the accuracy rate of data captured has now exceeded 98 per cent. This has come from the built-in quality checks to ensure that the right information is where it needs to be and to pick up variances where there should be none.
All of this is leading to better outcomes for clients.
I’m focusing on a cleaner and greener footprint for the industries we work in
AN ORIGINAL VERSION OF THIS STORY FIRST APPEARED IN INSIDE WATER MAY/JUNE EDITION