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Groundwater Monitoring

Our Consultants can undertake groundwater monitoring to gain an understanding of the groundwater levels beneath your site and to identify if any contaminants are present.

What is groundwater?

Groundwater is precipitation that has infiltrated the earth’s surface and is stored underground within pore spaces and cracks in soil, rock and sand deposits. The groundwater held in permeable water-bearing rock or sediment is known as aquifers and can be extracted through wells for drinking water or naturally form springs at the surface. When groundwater discharges into rivers or lakes it helps to maintain surface water levels and keep rivers flowing.

Why do developers need to consider groundwater monitoring?

The risk assessment of groundwater contamination is often required as part of the planning process to determine if any impact to groundwater beneath your site has occurred from historical or recent land uses.

The potential for groundwater contamination to be present on your site is initially assessed by forming a preliminary Conceptual Site Model, which considers the relationships between sources-pathways-receptors and identifies any plausible contamination linkages.  If the Conceptual Site Model identifies potential contaminants which are mobile in the water environment and may impact sensitive groundwater receptors, sampling and chemical analysis of the groundwater can be undertaken to determine the actual concentrations of dissolved contaminants in groundwater and inform whether any further detailed risk assessment or remediation is required. Groundwater monitoring can also determine if any free phase product is present which may require recovery as part of any remedial works.

Having knowledge of the groundwater levels beneath your site is also important to assist in the design of the development.  For example, a high-water table may mean that foundation will require deepening or soakaway drainage may not be suitable.  Seasonal or tidal variations in the groundwater levels beneath your site may also need to be considered in the design. 

How is groundwater monitoring carried out?

Groundwater levels are typically monitored from boreholes installed with standpipes.  Groundwater samples for chemical analysis can also be collected from installed boreholes.

Omnia Consultants can either undertake spot monitoring of the installed boreholes or if more data is required, continuous monitoring using data loggers.  Continuous monitoring is recommended if the Local Authority requires winter groundwater monitoring as part of the planning process to gain an understanding of ‘worst case’ conditions when groundwater levels are typically at their highest over the winter months. 

If you would like to speak to our team about groundwater level monitoring and/or sampling on your project/site, please get in touch.

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Winter Groundwater Monitoring