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Title: MTBE as a contaminant with field data on a release of unleaded fuel in an unconfined fractured aquifer
Author: R.M. Syminton
Document Type: Monograph
MTBE is currently the fastest growing petrochemical in the world, and can form up to 15 per cent by volume of unleaded gasolines. Driven by environmental legislation the long term anticipated trend is to increased use of MTBE in unleaded fuels. MTBE is recalcitrant in the groundwater environment and, despite its relatively low toxicity, more work is needed on long term effects. The chemical properties of MTBE differ from those of the BTEX components and have led to concerns about its behaviour in aquifers. MTBE is hydrophobic in a ternary system of MTBE, fuel, and water, and under aquifer conditions will concentrate approximately 80 per cent in the free product phase. MTBE is an order of magnitude more soluble than benzene and has been recorded to travel at the same rate as stable tracers in groundwater. Contrary to first indications, MTBE shows no cosolubility effects with the BTEX components. The weight of experimental evidence points to fact that MTBE is non biodegradable. Aqueous phase MTBE contaminant plumes have been observed as a halo around the plume of aqueous phase BTEX and MTBE. MTBE is commonly the first of the fuel components to be detected and, due to its low toxicity in comparison to the aromatic, is a comparatively good indicator of fuel spill. Field data on an MTBE fuel spill, and site conditions, are presented for an unconfined fractured chalk aquifer in south eastern England. The data has been interpreted to provide a post mortem account of MTBE behaviour. The remediation efforts are documented, and methods employed are evaluated with reference to a nearby public supply borehole.
Publisher: National Rivers Authority
Publication Date: 1993
Publication Place: Peterborough
Subject Keywords: ChemicalsOrganic compoundsWater pollutionGroundwater pollutionField experimentationLiterature study
Geographic Keywords: SuffolkCam and Ely Ouse catchment
Extent: 65; + appendices
Total file downloads: 285

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