The project
Our client brought us in during the latter stages of their construction project re-developing a brownfield site into new retail premises.
The site had several potential sources of ground gas issues, including a former underground fuel storage tank.
The client wanted to understand any issues posed from the previous land use, and the adequacy of any protection measures in place.
We were called in, at short-notice, to provide continuous ground gas and VOC monitoring to help our client understand this. Our aim was to establish if there were any unacceptable ground gas or vapour ingress inside the new retail units.
Our monitoring
We deployed continuous monitoring equipment to inside the retail premises in the sub-floor void and in the fabric of the building.
By deploying 3 instruments fitted with total VOC sensors, we collected continuous monitoring data for a 3 week period.
Using this type of continuous monitoring allowed us to generate high quality, robust data in a relatively short monitoring period.
By generating this data we could establish any ground gas or VOC ingress issues inside the retail unit that would pose a hazard.
The results
Our monitoring detected VOCs in the fabric of the building at a level which could be potentially hazardous. Our monitoring and data analysis identified the likely source as contaminated soils on the site.
However, we also demonstrated that there was no significant ingress of these VOCs into the occupied parts of the building.
Within just one week we had data confirming the nature, scale and location of the problem. This information could then help inform our client implement interim mitigation measures to target the issue.
The outcomes
Our rapid turn around on providing insights into the monitoring data, helped inform our client's approach to addressing this issue.
Based on our findings, our client installed a clean air blanket system as an interim mitigation measure. This system blows clean air into the sub-floor void thus creating a pressure barrier to minimise vapour ingress into the occupied parts of the buildings. These monitoring results also helped inform development of a longer term remedial solution.
As a result, our client gained temporary approval to open the development from the regulator. Thus our services helped our client navigate the regulatory system, keeping the project on track and the retail units opening on time.
And most importantly, the remedial solutions implemented based on our findings will help protect the health of customers and the workforce over the longer term.