Gas & Groundwater Monitoring

Monitoring wells can be installed within boreholes to enable subsequent monitoring of the soil atmosphere and\or recording of gas flows and groundwater levels. Representative samples of gas and\or groundwater can also be recovered from such installations.

Lithos engineers are able to specify well design in the field, after consideration of: the strata encountered; groundwater strikes; appropriate well materials; the required response zone etc.

Determination of porewater pressure in strata of low permeability is important for geotechnical design (eg slope stability assessment, retaining walls, deep basement excavations etc), but requires the installation of piezometers, rather than wells.

Hazardous Gas

Groundwater

Long-term monitoring of standpipes or piezometers is always recommended if water levels are likely to have a significant effect on earthworks or foundation design.

Monitoring of groundwater level is also required to comply with guidance provided in CIRIA Report C697:2007 which recommends that soakaways should not be constructed ‘in ground where the water table reaches a level within 1m below the base of the soakaway at any time of the year’.

Where groundwater is considered vulnerable to contamination, or may already have been impacted, monitoring wells are usually installed in order to obtain representative samples.