Webinar 31 and AGM | Remediation techniques and tools in action

We have 2 speakers for this webinar...

Thomas Aspray, Technical Manager, ERS Ltd

Use of qPCR testing in contaminated land projects

Quantitative polymerase chain reaction (qPCR) is a molecular biology technique which can be used to assess the potential for, and subsequently monitor, bioremediation of contaminated sites. Thomas has more than 20 years’ experience using polymerase chain reaction (PCR) based techniques and has recently setup a qPCR service at ERS Ltd for internal and external clients. This webinar will provide an introduction to qPCR - how it works, what assays can be used, and the ways it can be used in contaminated soil/groundwater projects.

Tom obtained a PhD in microbiology in 2004 where his project focused on bioremediation of pesticide contaminated soil using a novel gene bioaugmentation approach. Following a short postdoc placement, he moved to ERS for a two-year project to setup a treatability laboratory at the company and gain some industrial experience. He ended up staying with ERS for seven years designing/managing soil remediation projects and running applied and contract research out of ERS’ laboratory. Tom then spent six years at Heriot Watt University as lecturer/senior lecturer teaching microbiology and conducting research on organics recycling. Rejoining ERS in 2018 he provides technical support on soil and groundwater remediation projects. Tom also runs ERS’ treatability laboratory which includes molecular biology capability focused to the contaminated land sector. Outside of ERS, Tom is a board member of the British Society of Soil Science and on the Scientific Committees of WCSS 2022 and Remtech Europe.

Gareth Leonard, Managing Director, REGENESIS Ltd

Installation and operation of an injectable in situ permeable reactive barrier to prevent the advection of per- and polyfluoroalkyl substances at two UK airports

This presentation will discuss the installation of two injectable Permeable Reactive Barriers (IPRB) at two UK airports, using Colloidal Activated Carbon (CAC) in order to prevent the advection of per- and polyfluoroalklyl substances (PFAS). At the first location, a regional airport is divesting a large area at the edge of their site for residential housing development. At the fire training area, aqueous film forming foams (AFFF) containing PFAS have been used. PFAS was identified in the groundwater (PFOS observed at 320ng/L and PFOA up to 6,320ng/L) which presented an environmental risk.  

The second location is an international airport seeking to reduce their potential offsite liability by reducing the egress of PFAS from their fire training ground at the edge of the site. The contamination was found to be migrating beyond the site boundary and potentially effecting a downgradient spring and surface water.  

Geological, hydrogeological and engineering/injection testing was conducted at each location to provide accurate and detailed information on contaminant flux zones. This was then used to design the appropriate installation approach, including dose, spacing, depths and pressure.  

Two pilot studies were completed at each site using direct push injection was used to emplace the colloidal activated carbon within the target flux zones. Emplacement testing was completed to ensure the IPRB installation had been completed as desired. This was followed by six months of validation monitoring using multi-level wells.  

In both cases, the treatment was shown to be effective, reducing the contamination PFOS and PFOA below performance criteria. Following further engagement with the regulator, two full scale barriers were installed. The first barrier is 277m long and was completed by summer 2022. This site required remedial targets and the barrier was provided with a warranty to ensure ongoing efficacy and that the airport's off-site liability costs are defined and fixed. The second barrier is currently being installed along a length of 76m at the site boundary.  

A description of the activities and resulting measurements of the design verification testing will be shown, as well as how these informed the pilot test approach. Validation results from the pilot will be shared and discussed. A description of the on-site practicalities of installation and commissioning of the IPRB will be provided, including any issues encountered.

Gareth is the Managing Director of REGENESIS in Europe. He leads a dedicated team of in situ remediation specialists to provide solutions for the contaminated land industry. Gareth has over 20 years contaminated land experience and has provided successful remediation designs and implementation for over a thousand projects across Europe, the Middle East and Africa.