31 Mar 2008
Part 2A B20 Inspections
BAE Systems Environmental was commissioned by the Client to conduct various investigations for the purposes of establishing whether any part of the sites met the statutory definition of ‘contaminated land’ under Part IIA of the Environmental Protection Act 1990. The sites covered various previous land uses such as iron foundry, gas works, motor works, railway land and tube works.
Due to the particular characteristics of the local authority area, a number of receptors were identified including residential properties, water receptors and designated ecological sites such as SPA, RAMSAR and SSSI. Sites were firstly subject to a Preliminary Risk Assessment for Land Contamination involving a desk based study containing documentary research, site reconnaissance and development of the initial conceptual site model (CSM) to evaluate the environmental setting of the Site and identify potential pollutant linkages (PPL’s).
Secondly a Main Investigation was designed and implemented involving an intrusive ground investigation for the collection and analysis of soil, soil-gas, ground and surface water samples to examine the PPL’s and update the CSM. The Main Investigations employed a combination of systematic and targeted sampling techniques. Systematic sampling was used to characterise the nature of the deposits and general ground conditions at depth.
Targeted sampling was generally employed for delineation purposes and to provide additional information along likely migration pathways. A combination of trial pitting, window sampling and cable percussive drilling techniques were used to investigate the sites and where boreholes were sunk, groundwater and gas monitoring wells were installed to allow future monitoring.
In-situ testing was conducted during the site-works including falling head permeability testing to gain site specific information for input into risk assessment models. An important element of the works was ensuring sampling integrity and traceability. Rigorous decontamination procedures were adopted during sampling to ensure no cross contamination.
Samples were transported to the laboratory using a strict chain of custody. The analytical schedule in each case was sufficient to inform the CSM and to investigate the potential pollutant linkages previously identified by the desk study. In addition, site observations of olfactory and visual evidence of contamination informed the analytical programme.
The laboratory testing for a range of contaminants was conducted by BAE Systems Environmental’ in house UKAS/MCERTS accredited laboratory. We conducted generic and detailed quantitative risk assessments for human health, the water environment and other identified receptors. This involved the derivation of assessment criteria for human health where no published data is available, including for non standard land uses.
Our reports provided definitive statements as to whether the statutory definition of ‘contaminated land’ under Part IIA of the Environmental Protection Act 1990 had been met.
BAE Systems © 2008
