The site is an active landfill site situated in the north east of England. The company managing the site was unhappy with the groundwater monitoring infrastructure around the site margins.
ESI Ltd was commissioned to advise on locating and designing ten groundwater monitoring wells. Following agreement with the Environment Agency, we also provided independent construction quality assurance (CQA) services for the drilling and installation. The drilling and installation specifications were prepared by ESI prior to all site work and ESI undertook all drilling supervision as per the CQA plans.
Some of the boreholes were installed to replace poorly performing boreholes, which did not provide sufficient water for a representative sample to be taken. Others supplemented the downstream monitoring, as required by the Environment Agency.
Each location was trial pitted, prior to drilling, to a depth of 1.2 m bgl to ensure the avoidance of buried services. The boreholes were drilled via cable percussion.
The borehole depths were important to ensure good performance and adequate monitoring of both the Drift and Chalk aquifers beneath the site. The final depth of each borehole was determined by ESI’s field hydrogeologist and they were logged to British Standard BS5930.
Following installation, development of the boreholes was carried out by the client and produced successful results. ESI provided documentation of the works in the form of a CQA report that was submitted to the Environment Agency. The improved monitoring network is now giving satisfactory information for statutory reporting to the Environment Agency.