Innovation is essential – so why are avoidable problems still occurring?

Property developments will be increasing in volume as local and national governments struggle to keep up with the demands for housing. Developers are under enormous amounts of pressure when it comes to speeding up processes. Modern Methods of Construction (MMC) are being developed to reduce costs and speed up development.  Similar innovation is happening in ground investigation and risk assessment and GGS is in the forefront of the innovation of ground gas monitoring and risk assessment.

Continuous ground gas monitoring was once an interesting university research tool – it has become an industry best practice technique that saves both time and money.  Keep on reading to learn more.

In 1986, bringing in better mitigation for ground gas risk became more pertinent after a bungalow in the village of Loscoe, Derbyshire, exploded due to methane contamination. The bungalow in question was located near a landfill site used for domestic waste tipping. Although the unlined landfill was no longer in use, capping the site forced landfill gas to migrate. As waste decayed in anaerobic conditions, methane was generated at explosive concentrations. Following  a very rapid fall in atmospheric pressure drew the methane into the sub-floor voids beneath the property. Once the central heating system tripped in the explosive mixture was ignited and the explosion destroyed the house.

One of the most significant innovations has been the development of continuous ground gas monitoring. Developed in collaboration between GGS’ founder Simon Talbot and a team from Manchester University, this technique has been a real game changer. With our innovative techniques, risks are identified so that protection measures are focused and specific, instead of them being applied ‘just in case’.

Despite the potential fatal consequences of ground gas entry into buildings, errors are still made due to either poor quality investigations or ineffective protection measures.

Recently, GGS has worked on two newly completed housing developments where residents have had to be evacuated due to hazardous gases entering the homes near previously contaminated land. GGS’ investigations found the original gas monitoring, risk assessment and outline gas protection design were reasonable and appropriate but implementation had not been carried out to a high standard.

In the one case, a well installed gas membrane was subsequently compromised by a late change in design that introduced unsealed service penetrations that provided a direct link between contaminated soils and the internal living space.

In the other case, metalliferous ash waste was used as a subgrade to the houses which can have reactions with water generated hydrogen in relatively low volumes and as such the hydrogen molecule can penetrate gas membranes and sealed service penetrations that are protective of methane and other more common ground gases. Unfortunately, most carbon monoxide sensors used in both hand-held gas monitoring devices and in household gas alarms are cross-sensitive to hydrogen.

While appropriate professional services were employed in the site investigations, gas risk assessments and gas protection designs and validation, an overarching understanding of how the protection systems should work was lacking in both cases. It was only due to GGS’ expert knowledge and specialist monitoring equipment after these issues occurred that problems were identified, allowing suitable solutions to be developed.

It is incredibly important for ground gas risk assessments to be site specific and for any gas protection system to be designed and installed by people who are knowledgeable and experienced. Too many professionals and contractors unconsciously fall into the trap of believing, the gas risk is small and the gas protection isn’t really needed.

Sweeping assumptions and ‘just in case’ measures lead to poor workmanship, wasted effort and materials and increased costs. Ultimately, it is a less sustainable approach that will cause future problems.  Best practice is about using the latest innovative technology which can save money by focusing on site specific ground gas protection measures.

As we have explored, projects are still completing with short-cuts and without the use of innovative approaches. It’s key that an understanding of the need for site specific approaches are understood to reduce the risk of ground gas. Through this process, you will save time and future project costs.

Here at GGS we are continually innovating and looking at improvements to our technology and the services we provide. We are a team of geo-environmental scientists and so our approach is always one with innovation at the forefront. When it comes to your next project, make sure to choose innovation by choosing GGS. Get in touch with us today.