[BBDodge]

The area being cleared is "the Mound" which is contaminated land.

From the Hertsmere Council meeting minutes, 14.11.12:

"ELSTREE STUDIOS - MOUND CLEARANCE
The meeting was informed (report C/12/35) that funding of £4.5m had
been secured to fund the remediation of 3.8 acres of land at Elstree
Studios. The £4.5m was made up of a £2m loan received from
Hertfordshire LEP, with the remainder from the Council.
The land to be remediated was presently contaminated and specialist
contractors would be employed to return it to use. Once completed the
land could be used to build another stage or build workshops. The
addition of new facilities would help secure the future of the Studios as
a production site for both television and film."