As a routine on many sites, particularly those where significant Made Ground is present, either as infill material or as part of previous activities on the site, the risk of ground gases should be measured and assessed.
Typically during land regeneration gas investigations and monitoring form part of a Phase II site investigation, and it often forms part of the site investigation planning conditions. The NHBC also typically require gas monitoring to satisfy their requirements for building approval.
Current guidance suggests that these types of assessment should be undertaken over a minimum of 3 months requiring several monitoring visits over this period. The monitoring program should reflect differing weather conditions, particularly changes in atmospheric pressures.
If monitoring wells already exist we can visit your site, and using our range of up to date field equipment our experienced staff are capable of measuring levels of ground gases and down hole pressures to determine the significance of findings.
If monitoring wells do not exist then we are capable of designing a site specific monitoring strategy, and using appropriate drilling techniques we are able to install wells and undertake the required monitoring.
Gases including Oxygen, Carbon Dioxide and Methane along with Volatile Compounds/ Vapours, are measured and recoded along with the important flow rates. Other gases, which may be important on a site-by-site basis, might also be included in the monitoring suite.
Using this information and current guidance we can assess the risk to the end user and design suitable and cost effective remedial measures to protect them.