Risk assessment for contaminated land: Are you ready for new challenges?

27Mar / 2018

Risk assessment for contaminated land: Are you ready for new challenges?

Are the current methods of assessing risk in contaminated land sufficient to deal with new challenges, or are there new techniques that could deal with multiple contaminants on large and complex sites.

The recent publication of the government paper “A Green Future: Our 25 Year Plan to Improve the Environment” has raised questions over the effectiveness of existing methods of risk assessment and waste management for contaminated land. The report stated the need to improve waste management and soil degradation in both urban and rural areas in the UK, as well as the need to manage the issues posed by climate change.

Last week Ciria held an event to explore these and related issues in more depth. Are the current methods of assessing risk in contaminated land sufficient to deal with new challenges, or are there new techniques that could deal with multiple contaminants on large and complex sites? Simon Talbot, Managing Director of GGS, had the privilege of addressing the delegates on the matter of “Recent innovations in ground gas monitoring and development on former landfills”.Continuous monitoring for the sub-floor void

The conference was chaired by Richard Ogden (LQM) and other speakers included Kate Wooldridge (T & P Regeneration), Will Fardon (i2 Analytical) and Joanne Kwan (CIRIA).

The workshop element of the day discussed specific innovations needed by the industry to improve standards and reduce costs for regulators and developers. A key theme that emerged was the use of better ways of communicating technical information to stakeholders. Reports will always be required for legal reasons but they need to be concise and presented in a way that is easy for non-experts to comprehend. The use of graphs to help convey meaning is an effective technique, as is including clear and relevant imagery to illuminate technical subject matter.

Kate Wooldridge talked on the use of drone aerial surveys linked with 3D modelling. This combined method provides accurate site representations and data sets in order to improve communication and decision making for stakeholders.

Will Fardon spoke of the challenges and successes of laboratories in improving limits of detection through innovative techniques and environmental forensic approaches. Will made reference to the extraordinarily low levels of detection for emerging chemicals such as PFAS.

PFAS refer to the polyfluoroalkyl manmade group of chemicals that are used in every day household items from stain and water-repellent fabrics, non-stick products (e.g. Teflon), polishes, waxes, paints, cleaning products, and fire-fighting foams. Wherever they have been looked for in the environment they have been found including living organisms such as fish where they can bio-accumulate over time. There is increasing concern regarding these chemicals which are linked to increased cholesterol. Another concern is how a plume of PFAS contamination can be treated once it has been found. It is likely that we will hear a lot more about PFAS in the coming years.

Joanne Kwan’s talk on asbestos started with a history of its use in the UK. In the 1950s this ‘wonder material’ was advertised as being used in certain cigarette filters. Now its use is banned and up to 3400 people a year in the UK die from mesothelioma asbestos related cancers. Recent guidance documents on the sampling and analysis of asbestos are providing important guidance on addressing this hazard.

Simon Talbot’s presentation started with the recent publication of ‘A Green Future’, which stressed the importance of protecting the greenbelt and Third party verification of a ground gas membrane making the most of existing previously developed land. Ground gas and vapour contamination are just two of the technical issues to address in the re-development of former landfills. Fortunately there are now well established and constantly evolving methods for site monitoring, risk assessment and protection from hazardous gases in new buildings.

The acknowledgement of continuous monitoring as the industry best practice technique is one big step in the direction of widespread and accurate ground gas characterisation. In addition to this, the recent innovation of continuous gas-flow monitoring and telemetry enabled equipment has further improved our scope for understanding ground gas behaviours and producing systems to manage them.

While the risk assessment process has been significantly improved through technical innovation, the next challenge is raising the standards of gas protection installation. If gas protection is required it is essential that the measures are installed correctly, verified by a third party and protected for the life span of the building.

GGS now has the largest fleet of continuous monitoring instruments of any UK consultancy. Find out what we can do for you by calling 0161 232 7465.