Gas monitoring is usually undertaken as part of the contaminated land investigation, and is used to identify gas flows and concentrations of methane and carbon dioxide which can pose a risk to development structures.
Gas monitoring is required where ground gas may be an issue at a proposed development, for example on sites near landfills or areas of infilled ground, or where peat is present within the underlying ground. Data is acquired using a portable device.
The concentrations and flow rates recorded can be used to determine the level of gas protection required in a structure. Volatile organic compounds (VOCs) can also be monitored where risks from hydrocarbons may be an issue.