ExCAL is retained by a range of housing associations to undertake a wide range of studies for proposed housing developments.

Recent projects include desk studies, contaminated land assessments, ecological surveys, drainage designs and translocation of reptile species to enable development.


We have been retained to undertake numerous asbestos surveys by various Housing Associations.


ExCAL Ltd. was retained by Gwalia Housing to undertake a geo-environmental desk study on a parcel of land in Llanelli. Part of the site was found to lie over a former dock that had been infilled to a depth of around 11m. A remediation scheme was developed based upon the results of a Tier 3 Quantified Risk Assessment and hydrological risk assessment.  Ecological studies identified heptiles that required removal to enable development to proceed. ExCAL and Ofalis  were retained to capture and translocate the reptiles to receptor sites that had been identified and agreed with the Local Authority biodiversity officer.


ExCAL was retained by Dyfed County Council and Ceredigion County Council to undertake studies at three former lead mines, namely Abbey Consols, Castell and Grogwynion.


The scope of the investigation included comprehensive desk study, soil and spoil sampling, chemical analysis of spoil, streams and rivers (upstream and downstream of the sites) and concluded with development of outline remediation options and cost benefit analysis for each alternative.


Our team identified some unique issues associated with contamination regime at some of the mines. These included: -


  • Enhanced oxidisation of metal salts in air within spoil heaps following wetting by rainfall and subsequent exposure to atmospheric oxygen. This led to flushing of pulses of contaminants during heavy rainfall periods;
  • Pulses of metal rich groundwater being driven from some of the adits following periods of rainfall;
  • Different remediation solutions were appropriate to each of the sites to achieve environmental improvement.


Specialist ecological features (rare lichens) had developed on some of the spoil heaps as a result of the metal contamination and its ability to inhibit normal vegetation growth.


The study compared the cost of remediation works against the potential for improvements in water quality, and hence the likely increase in biota. This comparison was also made in the light of influences on water quality from other locations that were remote from the sites. By using this technique, we were able to estimate the potential remediation cost per biota that may be able to established post remediation, thus providing a measurable cost / benefit analysis.


The report discussed the structures present on the sites and evaluated techniques for safety improvement.

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ExCAL Limited, Capel Hendre Industrial Estate, Ammanford, Carmarthenshire, SA18 3SJ.

Reach us through or call us at 01269 831 606