ARGUS Umweltbiotechnologie GmbH ServicesCase Study biological groundwater remediation A fire brigade operation on a tyre production site resulted in contamination of groundwater with anionic surfactants, BTEX and Trimethylbenzene (TMB) from fire retardant. A biological/physical “Pump & Treat” process was selected for remediation. Groundwater capture was achieved via 2 pre-existing groundwater wells. The wells were equipped with a frequency regulated underwater motorised pump, complete with dry-running protection. The 2-stage groundwater treatment plant consisted of a biological stage as well as a downstream adsorption stage. Connection to the groundwater wells was attained below floor level. Works were put into practice by ARGUS. Discharge of remediated groundwater took place in a rainwater discharge system. Treatment Plant Specifications: Contaminant Concentrations: 88.0% of Surfactants and 92.7% BTEX/TMB were removed from groundwater in the biological stage. Pre-determined discharge limits set by the regulatory authorities were always met based on the total degree of remediation that was attained (99.9%). The remediation was able to be concluded after just 8 months. A total of 48670 m³ of groundwater was cleaned. Replacement of activated-carbon was not necessary due to the high degree of biodegradation. Groundwater treatment plant 13 175 BTEX/TMB 252 2.100 Surfactants Contaminant Inflow (Downstream) in µg/l Outflow bioreactor in µg/l Total Outflow in µg/l < BG < BG permissible limit in µg/l 200 10 Flow rate 8,5 m³/h Biological Stage 2 x 2 m³ Bio-Fixed Bed Reactor Adsorptions Stage 2 x 2 m³ Water Activated-Carbon Remote Monitoring |