Work to fill chalk mines that threatened Nash Mills homes should be completed by the summer.
The network of underground tunnels were first discovered in 2007 when a patio collapsed at a home in Highbarns, Hemel Hempstead.
A ‘community information centre’ has been set up within a mobile cabin in the street to keep householders up to date with work as the project continues.
Engineering firm BAM Ritchies – appointed by Dacorum Borough Council and project consultants Hyder –started drilling works on January 31.
Initial works focussed on the junction between Highbarns, Pond Road and East Green but now two more drilling rigs have been brought in to work on other areas.
This includes mines close to homes, which requires work within some gardens. Homeowners and tenants are being given two weeks notice of pending works, which are carried out between 8am and 6pm on weekdays only.
Council assistant director Shane Flynn said: “They are working really hard to minimise the impact on residents. If all goes well, the work should be completed by the end of June.”
The works mark the start of the end of a six year nightmare for householders whose properties have been blighted and unsellable.
It is believed the mines were dug in the 19th century to produce chalk for paper making at John Dickinson.