Concerns Identified Months Prior to Coal Tip Collapse

It has been disclosed that a disused coal tip, which collapsed in November and necessitated the evacuation of local residents, had been identified as a potential issue earlier in the year. An inspection report from August for the Cwmtillery tip in Blaenau Gwent, classified as a Category D site due to its highest potential impact on public safety, had previously noted multiple “features causing concern.” Towards the end of last month, inhabitants of the village observed a landslide consisting of substantial slurry and debris flowing through their streets, following heavy rainfall during Storm Bert. Blaenau Gwent Council, which holds ownership and maintenance responsibility for the tip, affirmed that preventative measures had been implemented and that the drainage infrastructure was functioning effectively. Approximately 40 residences were evacuated late on November 24 subsequent to a landslide at the inactive coal tip; the council informed residents they could reoccupy their homes five days thereafter. The council subsequently attributed the slip to a water issue, specifically a spring, which emerged during Storm Bert, saturating a section of the tip, thereby displacing material and directing it towards the dwellings situated beneath. The council reported that the “immediate risk” had been mitigated through post-slip remediation efforts, adding that the tip would undergo inspections twice daily during periods of heavy precipitation. A biannual inspection of the Cwmtillery tip was conducted in August by the Mining Remediation Authority, previously known as the Coal Authority, on behalf of the Welsh government, which did not identify any significant problems. The report, reviewed by the BBC, drew attention to “saturated ground associated with minor seepages located on the upper tip plateau,” in addition to “distortion of juvenile trees along the lower south west facing flank,” which was identified as a “potential indicator of shallow creep.” Nevertheless, the inspection also concluded that this was “a longstanding feature of the site” and that “no evidence of recent ground movement” had been detected. Furthermore, illegally dumped waste was discovered “within close proximity to the large diameter culvert close at the north western section of the lower tip plateau.” The report additionally noted that the assessment was conducted “without the benefit of a detailed site plan,” and that specific sections were so overgrown that a visual inspection could not be performed. Concerning drainage, the report indicated no new alterations, apart from a recently installed “clean stone land drain located along the crest of the lower lateau.” The document did not detect any changes in the internal structures of the tip’s main body, nor were there any modifications to internal seepage. Nevertheless, alterations were observed in seepage “above the tip,” with the report mentioning a “minor, ochreous seepage located adjacent to the flow path of issues which enter the site from just off the eastern perimeter where minor saturation [was] observed.” The report also noted shifts in surface erosion, observing that “the previously bare lower tip plateau” had “re-vegetated well since prior maintenance works,” alongside minor excavation activities resulting from “a series of small bike ramps having been constructed adjacent to the concrete canvas channel along its rear.” Blaenau Gwent Council verified that the landslip constituted a “singular wash-out of a former coal tip in the area.” A council spokesperson further stated that “mitigation measures for the seepage introduced earlier in the year,” coupled with “an enhanced drainage system,” were “working well.” The council clarified that the minor seepage mentioned in the report originated from the primary section of the tip, not the area where the landslide took place, which was situated at the periphery of a distinct section. They also indicated that the issue of fly-tipping had been resolved, with stones positioned to prevent off-road vehicles from accessing the site and the waste material cleared. In response to concerns about overgrown vegetation impeding inspections, the council explained that this constituted a “disclaimer” commonly included in most inspection reports, reflecting the scarcity of records for many coal tips and the extent to which many are wooded, thereby restricting access. Given the presence of severe weather warnings, the council affirmed its commitment to continue “to monitor the site closely.” The council further stated that the Mining Remediation Authority has also consented to conduct weekly inspections of the location. The council reported that reprofiling operations had been conducted subsequent to the landslip, involving the covering of the slopes with geojute matting. The council also indicated its intention to pursue “an independent assessment into the work carried out so far to provide further reassurance” and to collaborate with the Welsh government to obtain supplementary funding “to secure the long-term stability of the tip” for the protection of communities. The Welsh government had previously declared its commitment to being “fully committed to ensuring our coal tip communities are safe, both now and in the future.” It further stated, “The highest risk coal tips (category C and D) are regularly inspected by the Coal Authority and we will continue to work with our statutory partners throughout Wales to inspect and evaluate the highest rates tips in Wales.” Copyright 2024 BBC. All rights reserved. The BBC is not responsible for the content of external sites. Read about our approach to external linking.