Sixty holes have been drilled into the ground beneath a Hemel Hempstead housing estate to try and decipher what caused a sinkhole to appear there.
The 24 flats and 24 houses in the Oatridge Gardens development were built by Hightown Praetorian & Churches Housing Association on the site of a former brickworks. Many chalk mines and clay pits would have been used by the business.
It is now believed that heavy rainfall may have caused materials beneath the earth’s surface to dissolve and collapse into the cavities deep underground, causing the sinkhole.
Ten properties still lie empty, though the people who live in them have now been allowed to collect their possessions from inside.
The sinkhole was filled with foamed concrete on Friday, February 21, six days after it appeared. Geo-technical probing to find out the cause and whether there is any further threat to people living on the site was conducted throughout last week.
A meeting for people who live there will be held to discuss the results of the investigation so far. Sinkhole expert Clive Edmonds, who has been overseeing the work, and Hightown’s loss adjudication representatives will be there.
In the meantime, the housing association will work with the utility providers regarding reinstating all services to the properties.
Spokesman Emma Crump said: “Hightown’s efforts are being concentrated on supporting the residents with their temporary housing arrangements, and other short term issues.”
She said people from 32 of the properties can now return home at any time.
She said: “Some of these have chosen to move back in, 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 residents of the houses within the cordon have all been able to access their homes to retrieve possessions.”