Another cavity has been found beneath the Hemel Hempstead housing estate where a huge sinkhole appeared three weeks ago.
Truckloads of foamed concrete are being sent, again, to the Oatridge Gardens development, where there are 24 flats and 24 houses.
The material is being pumped into the underground hole today – the first hole, which caused the Earth’s surface to cave inwards, was filled in on Friday, February 21.
Ten properties still out of bounds after the 35-foot wide and 20-foot deep cavity appeared on Saturday, February 15, sparking a media frenzy. Luckily nobody was injured and the properties around it remain standing.
It is believed the hole may have been caused by building homes on the site of a former brickworks, where there were multiple clay pits and chalk mines.
Recent heavy rainfall could have made these underground holes much bigger, leading the Earth’s surface to collapse into them, experts say.
The new hole was discovered after 60 holes were drilled on the estate last week as part of a geo-technical probing process to make the area safe.
It is expected that the probing will continue for a further two weeks and the results of the probing will then need to be evaluated.
However, once the new cavity is filled it is hoped that the gas supply to the estate can be reconnected.
People who have been allowed back into their homes have been relying until now on electric heaters supplied by Hightown Praetorian & Churches Housing Estate, which created the estate. Some have chosen to stay with family and friends instead.
It is thought that further works to make the estate safe could take several months to complete if the probing discovers further cavities underground.
In the meantime, all of the buildings there are being monitored by Dacorum Borough Council’s building control team and Hightown staff.
Hightown spokesman Emma Crump said: “Ten households have chosen to move back in already and we have provided them with electric heaters until the gas supply is reconnected.
“Others have chosen to stay with family and friends for the time being or where this is not possible Hightown has arranged hotel accommodation locally.
“The insurance company have advised residents to continue paying rent and service charges in accordance with their lease as the insurers are covering the cost of temporary accommodation.
“The residents of the ten houses within the evacuated cordon have all been able to access their homes to retrieve possessions.”
Of the 48 homes on the site, 36 have been sold through shared ownership and 12 are still rented from Hightown.
The housing association and sinkhole experts working on the site met with the people who live there on Tuesday to discuss the work that needs to be done.
Emma Crump said: “These 48 homes in Adeyfield, Hemel Hempstead, were built for Hightown by Jarvis Group in 2008.
“In line with normal practice, before redeveloping the site, investigations into ground conditions, involving trial pits and boreholes, were commissioned from experts in that field, to recommend the right type of foundations.
“The history of the site was also taken into consideration. These reports were then used by specialist contractors in the design and construction of piled foundations.
“Dacorum Borough Council’s building control officers approved the design and monitored the works, and the National House Building Council also inspected the works and issued a structural guarantee.”