At Avada Environmental Ltd (Avada), we’re committed to tackling some of the UK’s most pressing environmental challenges. One issue that demands urgent attention is the contamination caused by per- and polyfluoroalkyl substances (PFAS), often dubbed “forever chemicals” due to their persistence in the environment. As a UK-based leader in sustainable remediation, we’re exploring innovative ways to clean up PFAS while minimising ecological harm. In this blog, we’ll dive into why sustainable PFAS remediation is critical and compare two key methods—in situ sequestration and pump and treat—focusing on their environmental impact. Let’s explore how Avada is helping shape a cleaner, greener future.
What Are PFAS and Why Are They a Problem?
PFAS are synthetic chemicals that have been used since the 1940s in everything from firefighting foams—think airports like Heathrow or military bases—to everyday items like waterproof clothing. Their strength lies in their carbon-fluorine bonds, making them incredibly durable. Unfortunately, that durability means they don’t break down naturally, lingering in soil, water, and even our bodies. Studies link PFAS exposure to serious health risks, including cancer, thyroid issues, and developmental effects.
In the UK, PFAS contamination is widespread, with hotspots around industrial sites, landfills, and areas where Aqueous Film-Forming Foam (AFFF) was used extensively. From the chalk aquifers of southern England to the rivers of Scotland, these “forever chemicals” are a growing concern—especially for drinking water, where 65% of Europeans, including many in the UK, rely on groundwater sources. At Avada, we see this as both an environmental and public health priority.
The Scale of the Problem in the UK
The numbers are stark. Across Europe, thousands of sites are contaminated with PFAS, and the UK is no exception. Known hotspots include major airports, military installations, and landfills, where decades of PFAS use have left a lasting mark. The Environment Agency and other bodies are increasingly detecting PFAS in groundwater and surface water, raising alarms about drinking water safety. For Avada, this reinforces the need for scalable, effective remediation solutions tailored to the UK’s unique landscape and regulatory framework.
Why Sustainable Remediation Matters
Traditional PFAS cleanup methods—like excavating soil and dumping it in landfills—are wasteful and energy-intensive, clashing with the UK’s net-zero ambitions. At Avada, we believe remediation must align with climate goals, reducing carbon emissions and waste while remaining cost-effective. With potentially thousands of contaminated sites across the UK, sustainability isn’t just a buzzword—it’s a necessity. Our mission is to tackle PFAS without creating new environmental burdens, protecting both ecosystems and communities.
Two Approaches: In Situ Sequestration vs. Pump and Treat
At Avada, we’re evaluating two leading PFAS remediation methods: in situ sequestration and pump and treat. Each has its strengths, but their environmental footprints differ significantly. Let’s break them down.
In Situ Sequestration: Locking PFAS in Place
In situ sequestration treats contamination where it lies—underground in soil or groundwater—without the need for pumping or heavy machinery. We inject sorbents like colloidal activated carbon (e.g., PlumeStop) or ion exchange resins into the subsurface. These materials bind to PFAS as groundwater flows naturally through them, acting like an underground filter. Globally, this method has been deployed at over 50 sites, including some in the UK, treating millions of litres of contaminated water with a single application.
The beauty of in situ sequestration lies in its simplicity. It’s quick to install—often within weeks—and requires no ongoing energy input. At Avada, we’ve seen firsthand how this passive approach minimises disruption to sites, making it ideal for rural or diffuse contamination plumes common in the UK.
Pump and Treat: Extracting and Filtering
Pump and treat, by contrast, is a more active process. It involves extracting contaminated groundwater through wells, treating it above ground with filters like granular activated carbon (GAC) or ion exchange systems, then reinjecting or discharging the cleaned water. It’s a tried-and-tested method, widely used at UK industrial sites with high PFAS concentrations, where containment is urgent.
However, pump and treat comes with a catch: it’s resource-heavy. Continuous operation demands electricity, regular filter replacements, and disposal of PFAS-laden waste—often via landfill or incineration. While effective, it’s a long-term commitment that contrasts with the low-impact ethos we champion at Avada.
Comparing Environmental Impacts
So, how do these methods stack up environmentally? Let’s look at two key metrics: carbon footprint and waste.
- Carbon Footprint: A Ramboll study found in situ sequestration emits 40-70 times less CO2 than pump and treat—over 95% more sustainable in some cases. For a typical UK site, pump and treat might generate hundreds of tons of CO2 over years, driven by energy use and waste transport, while in situ stays in single digits. For a nation aiming for net zero, this difference is critical.
- Waste and Resources: In situ produces no waste stream—once the sorbent is in place, it stays there, binding PFAS without replacement. Pump and treat, however, generates PFAS-saturated filters that pile pressure on UK landfills or require energy-intensive incineration. With strict waste regulations in place, in situ offers a cleaner alternative.
Cost and Feasibility for the UK
Cost is another factor where in situ shines. Ramboll’s life cycle cost analysis shows it’s 61-65% cheaper than pump and treat—say £500,000 versus £1.5 million for a mid-sized site. Its quick deployment and lack of ongoing costs make it scalable for the UK’s widespread, diffuse plumes. Pump and treat, while effective for high-concentration hotspots, locks site managers into decades of operational expenses—an approach less suited to smaller or rural sites.
At Avada, we see in situ sequestration as a game-changer for the UK. Its affordability and sustainability align with our goal of delivering practical, impactful solutions nationwide.
Challenges and the Path Forward
No method is perfect. For in situ sequestration, we need more UK-specific data on long-term efficacy—some studies suggest sorbents last decades, but field trials are essential. Pump and treat could benefit from innovations like renewable energy or advanced waste recycling, though these remain costly. At Avada, we’re excited about the potential for hybrid approaches—pairing in situ containment with targeted pump and treat—to optimise results.
The UK has a chance to lead on this. Funding from Innovate UK and collaboration with firms like Avada can drive research and real-world testing. We’re already working to bring these solutions to clients, from airports to rural landowners, ensuring PFAS cleanup is both effective and sustainable.
A Call to Action
PFAS remediation isn’t optional—it’s a public health and environmental imperative for the UK. At Avada Environmental Ltd, we’re advocating for sustainable solutions like in situ sequestration, which offers a lower carbon footprint, minimal waste, and cost-effective deployment. Pump and treat remains a vital tool, but its resource demands highlight the need for greener alternatives.
The time to act is now. Whether through policy support, investment in trials, or partnering with experts like Avada, we can tackle the “forever chemical” challenge without compromising our planet’s future. Contact us today to learn how we’re helping UK sites move toward cleaner, safer water and soil.