Geosyntec Consultants (Geosyntec) Ireland office (formerly Ford Consulting Group) has been retained by this client who has been required under IPPC to address contaminated soil and groundwater issues at their manufacturing site in Ireland. The project objectives have migrated from providing peer review to leading a detailed site characterization study and risk assessment in addition to performing laboratory and field based remedial trials. These are anticipated to lead to full-scale corrective action over a two year period.
Geosyntec's Scope of Services
Geosyntec's initial involvement in the project comprised a peer review of the work undertaken by another consultant. FGC was subsequently retained to undertake remedial pilot and bench-scale treatability trials for in-situ enhanced bioremediation of the main contamination source area.
The facility has handled a broad range of organic solvents over a 50 year operating history. Numerous potential source areas were identified from a Source Audit exercise reflecting changes in the chemical storage and production facilities used at the site during its lifetime. A review of the groundwater flow regime coupled with water quality data from their IPPC monitoring network was used to establish areas of potential concern and gaps in the current understanding of potential pollutant linkages.
The main contaminants of potential concern at this site are dichloromethane, xylenes, toluene, cresols, MTBE and THF. The fate and transport of this contamination is complicated by the presence of in-ground structures, preferential migration pathways in the drift and fractured bedrock. Parallel studies of five source areas at the site are ongoing and involve delineation and detailed risk assessments. The current delineation studies include detailed quantitative soil gas surveys/borehole installation for source areas delineation and multilevel well installations in the drift/bedrock to assess the flux of contaminants to the adjacent river and wider groundwater quality. Numerical groundwater flow models are in development to parameterize the risk assessment and aid in the remedial design.
The investigation works have enabled a clear understanding of the key areas of concern at the site in terms of the type, magnitude and distribution of contamination present. They have also facilitated the identification of the principal risk drivers for corrective action to protect human health, an adjacent river and impacts to wider groundwater quality thereby minimizing the scope of remedial works required. The investigation findings have also informed site staff tasked with reviewing the integrity of current containment measures.