Standen Tip, on Evergreen Farm, near East Grinstead, was closed in the early 1990s and turned to rough pasture.
Now HGVs will spend two years delivering more than 190,000 tonnes of inert clay and soil waste to the site to form a cap several feet deep.
A gas venting system will also be installed.
The work will mean 25 HGV deliveries per day between 9.30pm and 2.30pm Monday to Friday during term-time and 9.30am to 3.30pm during the school holidays.
The route will take the lorries along Imberhorne Lane and Saint Hill Road before entering the site from West Hoathly Road.
The idea of HGVs going to and from the site – past schools and nurseries – was the main concern raised in more than 240 objections sent to the council.
One objector wrote: “The infrastructure in East Grinstead already struggles with traffic.
“The roads are too congested, speeding is also a problem, and frankly adding HGV vehicles at this level is at best an accident waiting to happen, at worst a reason to no longer come anywhere near East Grinstead.”
This view was echoed in a statement from Metrobus to a meeting of the planning & rights of way committee on Tuesday (September 7), which ‘strongly opposed’ the application, saying the roads were simply not suitable for the HGVs.
But a highway & transport consultant working for the applicant said the current route to the site was preferable to sending HGVs through the High Street and Ship Street.
Another concern was whether the work was needed at all.
It was a concern shared by Jacquie Russell (Con, East Grinstead South & Ashurst Wood).
Mrs Russell said: “The Environment Agency are not stipulating that this work has to be done to avoid a public health crisis.
“Their concerns are wholly centred around any risk to public health with the disturbance of the hazardous contaminants already present.
“So I still remain unsure as to whether or not this is a genuine recovery operation required to mitigate the threat of leaching of contaminants and harm to public health – or whether it is purely a desire by the applicant to benefit from importing inert waste to reset the physical land form for some future use.”
Others, though, were concerned about the condition of the site.
A report to the committee said ground investigation works had identified elevated concentrations of benzo(a)pyrene, high levels of methane and risks to controlled waters through leaching.
Brian Quinn (Lab, Broadfield) said: “I feel this land site is dangerous to residents in the long future and also to the environment.”
In the end, the vote was split, with five for and five against.
It was left to chairman Richard Burrett (Con, Pound Hill) to use his casting vote and approve the application.
To view the application in full, log on to westsussex.planning-register.co.uk and search for WSCC/004/20.