Gas Works Sites, don’t be caught out…

… thinking such sites only occur in large towns.  In fact gas works site are extremely common across the UK and sometimes identified in some suprising locations.  If you are still referring to the old DoE Profile Gas works, coke works. and other coal carbonisation plants then you might be missing the fact that as described in CL:AIRE’s 2014 publication[i] Many hundreds of country house gas works were built in Great Britain and Ireland.”  It goes on to say that “Similar sized gasworks were also built at schools hospitals silent mills and some industrial buildings and factories.

Our knowledge of gas works sites and the problems they pose to land and water quality has greatly increased over the last few years. Redevelopment of land formerly occupied by gas works is a common occurence but the remediation of such sites to a suitable for use standard has not always been successful.  Furthermore our understanding, in some cases, has increased and what might have been considered suitable at the time of clean-up is no longer considered the case now.   As contaminated land specialists we are judged on the knowledge, standards and guidance at the time of providing advice on land quality and where applicable remedial measures ; so make sure you check out CL:AIRE’s latest publications on gas works, which also includes the output of a research project[ii] into currently available technologies to treat the common contaminants associated with former gasworks and gasholder sites.  CL:AIRE provides a listing of various sector related guidance at

This post was inspired by the fact that further research has been completed recently by  undertaking a Comprehensive Analysis of Manufactured Gas Tars.  Thanks to Prof Russell Thomas who brought this to the attention of the Land Quality community through the pre-christmas SoBRA meeting and subsequently on JISCMail. Essentially this research has looked at 16 tar samples produced by 5 distinct production processes:

  • Low Temperature Horizontal Retorts;
  • Horizontal Retorts;
  • Vertical Retorts;
  • Carbureted Water Gas; and
  • Coke Ovens (High Temp., not low Temp. Coalite).

In Prof. Russell Thomas’ JISCMail posting he made the following  observation “Despite the large number of compounds detected, only 173 compounds were identified within every sample, which may be of particular importance from a regulatory standpoint. It should also be noted that each production processes produced tars with different chemical signatures and hazards. Studies demonstrating health risks using coal tar therefore may be dependent on the type of coal tar used.” For those interested in reading the papers produced as a result of this research details are below:

  • Comprehensive database of Manufactured Gas Plant tars – Part A Database – Rapid Communications in Mass Spectrometry, May 2017 DOI: 10.1002/rcm.7901
  • Comprehensive database of Manufactured Gas Plant tars – Part B Aliphatic and Aromatic compounds – Rapid Communications in Mass Spectrometry,  May 2017 DOI: 10.1002/rcm.7900
  • Comprehensive database of Manufactured Gas Plant tars – Part C Heterocyclic and hydroxylated PAHs – Rapid Communications in Mass Spectrometry,May 2017 10.1002/rcm.7904



[i] CL:AIRE, 2014. Gasworks Profile A : The History and Operation of Gasworks(Manufactured Gas Plants) in Britain. ISBN 978-1-905046-26-3

[ii] CL:AIRE 2015, Soil and Groundwater Remediation Technologies for Former Gasworks and Gasholder Sites