Geotechnical & Geological Engineering

, Volume 24, Issue 4, pp 809–818 | Cite as

Geo-engineering problems at Llwyneinion hazardous waste site near Rhosllanerchrugog, North Wales

  • Douglas Nichol
Article

Abstract

At Llwyneinion, a clay pit excavated in Carboniferous Bettisfield Formation was utilised for hazardous waste disposal prior to 1972. Approximately 94,000 t of acidic asphaltic sludges and pitches was poured directly into the pit together with 7500 t of spent bentonite containing absorbed oil. Numerous chemical drums were also dumped in the sludge. The unlined acidic asphaltic sludge and pitch lagoon occupies 1.3 ha, ranges up to 10 m deep and is underlain by fissured strata and extensive mineworkings including three shafts. The heterogeneous asphalt waste has developed a semi-solid asphalt layer at the base but mostly remains in a viscous and mobile condition. A surface layer of rainwater less than 0.4 m deep covers the waste. Surprisingly, detailed hydrogeological studies of the area surrounding the acidic asphaltic sludge and pitch lagoon failed to disclose any significant contamination of aquifers, however regular monitoring of water conditions is performed as a safeguarding measure. Various remediation strategies have been assessed and rejected. They fall into two main categories; those involving on site treatment of the acidic asphaltic sludges and pitches and encapsulation and those aimed at removal of the material to facilities elsewhere in the country. Investigations and deliberations continue in order to determine the optimum way forward.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Consultants in Environmental Sciences Ltd. (1986) Production, Treatment and Disposal of Acid Tars in the United Kingdom. Final Report. Department of the Environment Report.Google Scholar
  2. Hains, B. A. (1991). Applied Geological Mapping in the Wrexham Area: Geology and Land-use Planning. British Geological Survey Technical Report WA/91/4.Google Scholar
  3. Kerr, K., Probert, S. D. 1990Fluidised-bed incineration of acid tar wastesAppl. Energy35189243CrossRefGoogle Scholar
  4. LaGrega, M. D., Evans, J. C., Acuna, C. O., Zarlinski, S. J., Hall, D. S. 1990Stabilization of acid refinery sludgesJ. Hazardous Mater.24169187CrossRefGoogle Scholar
  5. Milne, D. D. (1985). Acid tar: production, treatment and disposal. MSc thesis, Department of Civil Engineering, Imperial College of Science and Technology, University of London, 75pp.Google Scholar
  6. Smith, E. T., Bromley, J. 1982

    The British experience – clean up: technical aspects

    Highland, J. H. eds. Hazardous Waste Disposal – Assessing the ProblemAnn Arbor ScienceAnn Arbor, MI188201
    Google Scholar

Copyright information

© Springer 2006

Authors and Affiliations

  • Douglas Nichol
    • 1
  1. 1.Wrexham County Borough CouncilWrexham

Personalised recommendations