CSB 01 - Site characterisation in support of monitored natural attenuation of fuel hydrocarbons and MTBE in a chalk aquifer in Southern England (2002)

This Case Study Bulletin describes a research project, which was carried out to determine whether monitored natural attenuation was a viable option for managing fuel hydrocarbon contamination in a chalk aquifer in southern England. The research, which was carried out from February 2000 to March 2001, was undertaken by the University of Sheffield on behalf of TotalFinaElf at a petrol filling station site. The study was commissioned following the accidental release of approximately 55,000 L of unleaded petroleum from a ruptured underground storage tank in February 1999.

The aims of the research were to i) assess the transport and fate of petroleum hydrocarbons in the Chalk aquifer beneath the site and ii) determine whether monitored natural attenuation was a viable means of managing the site.

CSB 02 - A constructed wetland to treat acid mine drainage from colliery spoils at Quaking Houses, County Durham (2002)

This Case Study Bulletin describes the design, construction and operation of a full-scale compost wetland to remediate a watercourse contaminated by colliery spoil leachates at Quaking Houses, County Durham. Drainage from an acidic spoil heap containing elevated concentrations of iron, aluminium, manganese and zinc, was discharging into the Stanley Burn, a third order tributary of the River Wear. Based on the success of laboratory studies and a pilot-scale compost wetland, a full-scale wetland system was designed for the site and installed. The residents of Quaking Houses had significant influence over the acquisition of funding to treat the contamination, in the design of the chosen passive treatment solution and in its construction.

CSB 03 - Portadown biological reactive barrier (2005)

This Case Study Bulletin describes a research project which evaluated, at laboratory-scale and field-scale, a biological permeable reactive barrier (PRB) for remediating organic contaminants.

A small, former gas works site (15,000 m2) in Portadown, Northern Ireland was made available as the study site. The joint DoE Northern Ireland - EPSRC research project involved site study (trial pits, boreholes, chemistry, hydrogeology and microbiology), risk assessment, formal planning permission, regulatory agreement, discharge consents, laboratory treatability for full-scale design, hydrogeologic and civil engineering design, modelling and finally construction of a full-scale PRB including 330 m of slurry wall (to 13 m depth) and the 20 m3 reactor.

CSB 04 - Mine water treatment at Wheal Jane Tin Mine, Cornwall (2004)

This Case Study Bulletin describes the construction and performance of both active and passive systems to treat contaminated mine water at the Wheal Jane tin mine in Cornwall.  The emphasis is on the passive system.

The Wheal Jane tin mine was closed and abandoned under the Mines and Quarries Act in1991. Closure of the mine resulted in the termination of mine dewatering operations and a rise in water levels. In January 1992, there was a sudden and uncontrolled release of highly contaminated mine water into the Carnon River and Fal estuary. Oxidation of the iron rich mine water generated orange-brown discolouration over a downstream drainage area of more than 6.5 x 106 m2 including parts of Falmouth Docks.  Initially, a pilot passive treatment system (PPTP) was constructed to carry out research into possible long term passive remedial solutions at the site. Subsequent to this, an active treatment system was constructed.

CSB 05 - Remediation trial at the Avenue Coking Works using stabilisation/solidification and accelerated carbonation technology (2006)

This case study bulletin describes the application of Stabilisation/Solidification (S/S) and Accelerated Carbonation Technology (ACT) to contaminated materials at the Avenue Coking Works, Chesterfield. This was the second field-scale demonstration of ACT.

The main objective of the trial was to assess the effectiveness of ACT in treating three different contaminated materials from the site: waste tip, plant area and spent oxide material. The results would be compared against ‘traditional’ cement-based S/S techniques, to assist in the choice of the optimum treatment process for the site. The ultimate aim of the study was to assess the potential for reusing treated material on the site; consequently, the chemical composition, engineering capability and durability of the treated materials were considered.

CSB 06 - Remediation Trial at the Avenue Using Thermal Treatment (2006)

This Case Study Bulletin describes a thermal treatment field trial on contaminated materials at the Avenue Coking Works, Chesterfield.

The trial was undertaken in 2001 to assess the suitability of Enhanced Thermal Conduction (ETC) technology to treat materials from the site.  The ETC technology uses heat provided by diesel fuelled burners to heat contaminated material and desorb contaminants into the gaseous phase, which is then extracted and treated. The contaminated material is covered by a steel cover which retains heat and the volatilised gases.  The success criteria related to how efficiently the technology could reduce levels of a broad range of contaminants at the site, whilst demonstrating a cost-effective alternative to landfill.

CSB 07 - Remediation Trial at The Avenue Using Soil Washing

This Case Study Bulletin describes a soil washing field trial on contaminated material from the Avenue coking works site in Chesterfield.

The pilot demonstration project was carried out using plant-scale equipment.  The main objectives of the trial were to evaluate the feasibility of using soil washing to (i) remove contaminants from the soil, and (ii) maximise the amount of treated material which could be recycled on the site as construction backfill and to evaluate the costs of large-scale soil washing on this site.

CSB 08 - Public affairs and communications on contaminated land projects (2007)

This Case Study Bulletin describes a case study of the remediation of South Car Park, Coventry. Its focus is on aspects of risk communication which could be applied to other contaminated land projects.

South Car Park was once part of the former Courtaulds main rayon production works in Coventry. Historically, the site housed an effluent plant and was used to store coal and the chemical carbon disulphide (CS2), used in the manufacture of viscose, between about 1904 and 1967. Thereafter, it was gradually converted to use as a car park.

The risk assessment raised the question of the potential for off-site migration of CS2 although it was uncertain as to whether any significant migration had occurred. To resolve this uncertainty, Akzo Nobel commissioned an investigation to determine the extent of any off-site migration and assess the associated risks to residents in the adjacent estate.

CSB9 - Remediation of a Former Landfill in Coventry: A Practical Application of the Definition of Waste: Development Industry Code of Practice in a Cluster Project.

This bulletin was written by VertaseFLI and describes the successful application of the Definition of Waste: Development Industry Code of Practice in a Cluster arrangement at a former landfill in Coventry.  To provide background and context, the bulletin introduces the key aspects of this Code of Practice to help explain the decisions that were made at the site. The success of this project can be largely attributed to the careful management and organisation of all the stakeholders involved which was aided by an overriding consensus that the principles of the Cluster arrangement were fundamentally right and that it would yield financial and environmental benefits. The stakeholders were Coventry City Council as a client, their consultant, a consortium of three different house builders, the consortium's consultant, the local authority contaminated land officer, and three different sections of the Environment Agency.

Benefits of the project included less traffic congestion on outer roads, less visual and noise pollution via a vastly reduced number of lorry kilometres travelled, reduced use of primary aggregates, and reduced use of valuable landfill void space. Of particular note was the better quality assurance provided on the use of imported soils. Whilst it was always envisaged that the anticipated environmental and financial benefits of operating a Cluster arrangement on the project would be significant, actual reductions of approximately 80% for CO2 emissions, haulage distance and fuel use, and landfill disposal and import cost savings of £1,490,000, were more than anyone expected.