This week yet another sinkhole opened formed in an alley-way just off Ripon’s main high street as the Yorkshire town continues to live up to its name. The event led to the evacuation of a nearby supermarket as emergency services assessed and cordoned off the area…
Terrafirma becomes first commercial organisation licensed by The Law Society to produce official CON29M Report
Terrafirma, an expert provider of environmental information and data intelligence, has become the first commercial organisation to be licensed by The Law Society as a ‘Report Producer’ of the official CON29M Report, a mandatory requirement for property and land purchase in coal mining areas. The Terrafirma CON29M Report offers property and legal professionals a level of interpretation, risk transfer and client protection not previously available and contains an expert professional opinion that is backed by comprehensive terms and conditions, with all liability for the outcomes of the report passing to Terrafirma, protecting the client, lender and solicitor.
Visit the dedicated website: www.terrafirmacon29m.co.uk for more information.
Late on Saturday 28th April, a 40ft deep and 3ft wide hole opened in a car park in Garth-An-Creet, St. Ives, Cornwall. Local emergency services were called to assess the scene and undertake work to prevent the hole from widening and affecting nearby properties. Subsequent investigation by Terrafirma concludes the hole was created by the collapse of a disused mine shaft.
A sinkhole discovered at 6pm on Wednesday (18/04/2018) has appeared on the A40 near Llandovery in Carmarthenshire forcing the closure of the road in both directions.
A sinkhole reported on 02/04/18 has appeared in Merthyr Tydfil within a new build site, Cwrt Aneurin Bevan. The sinkhole which is reportedly 20 ft (6m) deep has resulted in local residents losing access to their new homes.
A sinkhole which is said to have collapsed on the 14th February 2018 appeared in the corner of one of the Morriston RFC rugby pitches in Heol Gwernen, Cwmrhydyceirw.
In the past few weeks, Britain has been hit by an earthquake, the beast from the east and sinkholes. We at Terrafirma focus on the latter. From collapsed mine workings to naturally unstable geological conditions, sinkholes are a very real and re-occurring risk to life and property.
Between the 14th-16th of February two sinkholes opened up in the City of Norwich, the second of which spanning over two front gardens in Meadowbrook Close. Although described by the water board as a ‘’red herring’’, a burst water pipe in the vicinity of the depressions remains a possible cause for the collapses. This said, mining cannot be discounted here, with the area known for its historic underground chalk extraction, which is also thought to have caused another sinkhole 250 metres northeast of the Close in 2015.
Further to this, on the 14th of February, on the pitches of Morriston RFC, Swansea, another sinkhole opened. Reported to the Coal Authority on the 19th, social media blamed the 4.4 magnitude earthquake that rocked the west of the country on the 17th. Further investigations by Terrafirma came to a different conclusion, the playing fields, already the Site of 2 past mine entry collapses, are underlain by deep mine workings and a coal seam along which multiple known mine entries and historical collapses are recorded. The sinkhole itself follows this same trend, and therefore, is most likely the result of an unrecorded mine entry or more ancient 'bell pit' mine collapse.
Not all sinkholes can be linked to mining however, as natural ground movement is another key geological avenue when it comes to subsidence and collapse. Ripon, a small town in North Yorkshire is geologically famed for natural subsidence issues, resulting from the natural dissolution of gypsum beneath its town footprint. On Saturday the 24th of February, another sinkhole open up in near the towns leisure centre, which was subsequently closed whilst remedial work was undertaken. This sinkhole is the 5th in only 6 months recorded by Terrafirma and our partners.
On the 4th January 2018, a 1.2m deep, 0.6m wide ‘’sinkhole’’ opened next to the Whitehaven – Workington railway line, near the coastal village of Harrington in Cumbria. For fears of the hole expanding and damaging the rail line, services were delayed in order to complete emergency repairs and infill the void. Initial observations have led rail engineers to speculate that a collapsed drain or coastal erosion accelerated by Storm Eleanor are the cause of the collapse. However, the correlation with known mine entries and collapses along the railway line have prompted Terrafirma to research further to see if past coal extraction may in fact be the cause.
As the year rapidly draws to a close, at Terrafirma, we thought we would summarise this amazing year, including providing a top 5 of our #WhatLiesBeneath blog and our key 2017 events.
2017 has been a year of change at Terrafirma. Time and resource was invested in the Terrafirma brand, sales, marketing and educational material – creating a recognisable and professional brand identity for the first time, embodied by our new website terrafirmasearch.co.uk and our tagline ‘understand the ground’.
In 2017, Terrafirma provided over 250 hours of training, workshop and Continued Professional Development for professionals across the UK. We have also focussed our academic projects on exploring the hidden hazards that the ground can pose – including an industry-first analysis of sinkholes in the UK. This analysis cumulated in late November with a three-part documentary series exploring Sinkholes, on Channel 5. Terrafirma were heavily involved in the research and production material for the series and Terrafirma CEO, Tom Backhouse, co-hosted an episode investigating the impact of mining sinkholes on people, property and investment across the UK and the world.
As we look back on this exciting year and our mission to continually educate professionals and the public to the risks that the ground poses we have picked out our top five events and the top five ‘What lies Beneath’ blog posts:
Exploring the themes behind Sinkholes in the UK
At Terrafirma, understanding the ground is what we do best: Our CEO Tom Backhouse was recently asked to feature in Channel 5’s documentary Sinkholes to provide an expert insight into the roots behind their cause. Inevitably then, when high profile sinkholes such as those at Fontmell Close, in St Albans or in Wednesbury, causing up to six million pounds of damage and evacuating families from their homes, we ask ourselves “can sinkholes be predicted?”.
Over the last few months and years, the experts at Terrafirma have meticulously observed, understood and recorded each sinkhole as they form. Now, armed with this information, Terrafirma is proud to present a new dataset and report feature; ‘SinkholeAlert’, allowing our team to examine the common themes behind these hidden dangers.
Delve behind the scenes of the Channel 5 documentary on Sinkholes.
The word sinkhole has become a term broadly used term to describe any hole in the ground created by erosional processes and the drainage of water. Ground hazards in the UK are often synonymous with the word sinkhole which can span from just a few feet in diameter to gigantic chasms large enough to swallow whole buildings.
They can have devastating consequences as can be seen on the new three-part Sinkhole documentary which began on Monday 20 November on Channel 5 and features extensive commentary from sinkhole expert and Terrafirma CEO and founder, Tom Backhouse.
Terrafirma CEO Discusses Lender Policy on Mine Entries.
Earlier today, Terrafirma's CEO and Founder, Tom Backhouse featured on the new series of the Rip Off Britain: Live Series on BBC One. Tom was invited on to offer advice to a frustrated home-owner who has fallen victim to her property being located close to an historical coal mine shaft, making it impossible to sell.
The property has seen its market value drop by £61,000 and despite being up for sale multiple times, it remained unsold earlier this year at a property auction in the West Midlands.
Land. A word that is defined by its ownership, purpose, value or location and is often viewed, from a local, regional or national economic perspective, for its agricultural or development potential. However, land in the UK is also defined by our geological and extraction history, both of which can pose significant risks to property, investment and people.
The formation of a ‘sinkhole’ beneath a property in Wednesbury, West Midlands has received abundant coverage from the mainstream media during the last week. At Terrafirma, we have been looking into this event to try and understand more about its cause and wider context.
On September 25th, 2017, a large sinkhole appeared on the pavement at a pedestrian crossing in Brow Gate, Baildon, causing traffic disruption indefinitely. According to a pedestrian, the sinkhole opened within a time frame of a few minutes. Gas engineers from Northern Gas Networks are assessing the damage.
The local geological conditions are favourable for subsidence; superficial till (composed of clay) deposits shrink under prolonged dry conditions and 19th Century, unrecorded utilities infrastructure may be the cause of the collapse.
A sinkhole has been reported to have occurred within part of Beechwood Avenue, Cimla in South Wales. This is the second reported sinkhole in the neighbourhood after another ground collapse, later identified to be a mine shaft, opened up in January of 2016. The sinkhole is now being investigated to identify whether it is associated with the extensive shallow coal mining known to have occurred in the area during the 18th and 19th Centuries.
The age of solely relying on data in environmental risk assessment is over, with a visible shift in the way professionals perceive risks such as contaminated land and flood. Where historically data alone was enough to accept due diligence, now both a professional opinion and interpretative data modelling is a standard in assessing and managing these environmental hazards.
However, despite the significant annual financial expenditure (between 4 and 15% of all Buildings Insurance Claims in the past 5 years were attributed to subsidence) and the increasing visibility of the ‘Sinkhole’ phenomena, this shift in due diligence process has not been replicated in assessing the risks the ground pose.
On May 2017, an 8-metre-deep sinkhole appeared on High Street Green, Hemel Hempstead, causing the road to be closed until around November. This is in the same neighbourhood (within 200 metres, or less than a 10-minute walk) from the 6-metre-deep sinkhole that opened up in Oatridge gardens in 2014, resulting in the evacuation of 17 people from their homes .
On 29th June 2017, a 6 metre wide and 3 metre deep sinkhole opened in the middle of a busy Liverpool commuter route to the M62, Edge Lane, closing it for several weeks. United Utilities were called to the scene to assess the damage and discovered the sewer 6 metres down was blocked. The area rests upon superficial till rich with clays which are prone to subsidence which in turn can damage subsurface utilities.
The collapse of a chalk mine in west Reading forced the immediate evacuation of dozens of residents. These residents then suffered for years due to the extensive and drawn out remediation of the affected area, but eventually had their patience rewarded after the works finished and the area declared safe once again.