£2 million Hatfield chalk mine probe begins
08:00 10 November 2012
NEARLY £2million is being spent investigating a network of chalk mines below three streets in Hatfield amid fears of future subsidence.
Ground investigations are being carried out in the gardens of 19 homes to find out the extent of a network of chalk mines.
The work, which began last week, follows an investigation around Chantry Lane which revealed a ‘high likelihood’ of mines.
Work to stabilise the ground started last week, with contractors Ian Farmer Associates using probe holes and boreholes to confirm the extent and condition of mine workings and to enable CCTV surveys to be undertaken.
The exploratory holes will be in the gardens of 19 properties in Chantry Lane, Vigors Croft and Bishops Rise.
The survey will be repeated in January 2013 after the ground investigation site works, which will be followed by the contractor’s laboratory testing and factual report early in 2013.
The Homes and Communities Agency has set aside over £1.9 million for Welwyn Hatfield Council to fund work needed on the chalk mines.
Welwyn Hatfield Borough councillor Alan Franey, deputy leader and executive member for resources, said: “We are pleased that almost £2 million of funding has been allocated to our borough council for this work which will help to remedy any damage caused by chalk mines in the Chantry Lane area.
“The contractors have assured us and the residents that they will keep disruption to a minimum and that, once the work is done, they will carry out surveys to find out the extent of reinstatement required, including things like cleaning of any grout damage to buildings, reinstating gardens and repairing highways and pavements.”
Following the investigative drilling, the treatment works, consisting of bulk infilling of open voids and compaction grouting of collapsed ground is programmed to start on site in September 2013.
It is expected to take approximately 16 weeks and the whole project should be completed in spring 2014.