The blaze, near junction8 of the M1, left 15 residents with an "intermittent" water supply for several days as firefighters used supplies to tackle it.
Hertfordshire Fire and Rescue Service said "a conservative estimate" was that the blaze, which is near junction8 of the M1, "will still be ongoing a week from now".
Firefighters were called on 10 November to the site, near junction8 of the M1, to tackle a blaze in what was described as being a 20ft (6m) high pile of timber.