Remediation of Blue Billy contaminated soils at Tondu

Remediation works involving the E-Clay stabilisation of Blue Billy (Gas purification spent oxide) at Tondu

Site Background & History

The site was the former Archbishop McGrath School Campus located in Tondu. The site area being approximately 0.88 hectares.

Historical maps showed the presence of coke ovens and railway siding as being present.

The site had planning permission for residential development for Linc Cymru.

Planning conditions stipulated a requirement for remediation to be “undertaken in accord with the document Integral Géotéchnique (Wales) Ltd, April 2017; Remediation Strategy Report”. Which included a provision for further investigation and assessment of any unexpected contamination.

Previous site investigation had highlighted the presence of “Blue Billy” contamination, spent oxide from the coking of coal and historical town Gas Purification.

Remediation Works

Envirotreat developed aa approved remediation strategy to enable reuse of treated on site. The strategy was both commercially viable and shown not to impact / delay the overall program of works.

The approved remediation strategy involved the excavation the contaminated soils and E-clay stabilisation to enable reuse on site. Treated / validated soils were used as fill material within the overall development.


A comprehensive Validation Report was produced on completion of the works by Envirotreat. The Validation Report documented the works undertaken and confirmed that the prime drivers for the remediation had been achieved, the protection of Human Health and groundwater. 

Integral Géotechnique approved the Envirotreat Validation Report prior to submission to the regulators.

This project demonstrates that contamination issues that have been historically difficult and costly to address (cyanide in this case) can be successfully treated using Envirotreat E-Clay Stabilisation technology.

Delivering land you can develop

Envirotreat are a specialist remediation solution provider and sole providers of E-Clay technology