Roughton Moor Woods - off Kirkby Lane - remain at the centre of a mustard gas alert.
Although 140 canisters of the gas have been removed, the immediate area around where they were discovered has been contaminated and is still cordoned off.
East Lindsey District Council, has taken over responsibility for the site and confirmed some of the gas had leaked into the soil from canisters that were believed to have been dumped, either during or just after the Second World War.
Leading experts from the Defence Science and Technology Laboratory at Porton Down in Wiltshire have been called in to help to ensure the long-term safety of the site.
An ELDC spokesman said the canisters had been taken away and destroyed and the focus was now on ‘decontaminating the site.’
He added: “That may involve taking away the soil from the site or leaving it on the site and treating it there. We are working with the Defence Science and Technology Laboratory.”
The cost of making the site safe will be taken on by the Ministry of Defence - and not ELDC.
One resident, who lives close to Kirkby Lane, said: “The woods are very popular, especially with dog walkers everyone understands how important it is to stay away until everything is declared safe.
“From what I’ve been told there is a sentry box and the site is being guarded. We don’t know when we’ll be allowed back but it could be months.”
Three people - including a Woodhall Spa man - were arrested on suspicion of possessing a noxious substance and released on bail.
Ten canisters were also found in a lake at Stixwould.