Kent to spend £1.1 million upgrading closed landfill

The plans were approved last week (19 May) at its environment committee.

This comes after a number of environmental issues which could result in further harm were noted by the site’s management.

According to the approved report which went before the council, the site produces high volumes of leachate, which could pollute nearby watercourses if not managed effectively, as well as landfill gas predominantly consisting of methane gas.

There are also “persistent areas of elevated landfill gas emissions”, which are venting greenhouse gases to the atmosphere.

According to the council, the works include installation of a geosynthetic clay liner and associated drainage to reduce leachate generation and upgrading the existing landfill gas collection system.

Issues

The North Farm landfill site was operating from the early 1960’s, taking predominantly domestic waste from the Tunbridge Wells area. It closed in early 1990’s, with a gas extraction system and flare stack installed in 1995.

The collection system now faces age-related issues, which have flared up alongside several others during monitoring of gas and waters undertaken by the council’s waste management.

Additionally, the capping soils laid when the site was closed are not able to prevent surface emissions to atmosphere across the entire site, the council said.

Leachate, which is produced during rainfall, is collected in the drainage ditches around the perimeter of the site. Under the current system, any rain is collected by the same drainage system and pumped off site for treatment, resulting in “significant quantities of leachate”.

Finance

According to the council, its decision to install a geosynthetic clay liner is “estimated to be in the region of £1.1 million, subject to no soil import required”. There is currently a committed budget allocation of £1.007 million for the project.

With the upgrade to the gas collection system costed at a further £102,000, the council explained that “additional funding is available to meet this environmental priority”.