NCC Operation & Maintenance of Corby Closed Landfill Site

Northamptonshire County Council (NCC) wishes to invite tenders for the Provision of the Operation and Maintenance (O & M) Services of the Corby Closed Landfill Site.The landfill, covering about 13ha and with up to 16m deep waste, was created in a quarry void left from the opencast mining of ironstone. Waste disposal was from early 1970s until early 1990s when the site was restored with around 1m of clay and soil. The waste inputs were dominated by municipal solid waste (MSW) type materials, with co-disposal of some industrial and special wastes as defined at the time; some wastes were imported from the Sixfields Landfill in Northampton, with wastes that had been originally deposited in the 1950s and 1960s. The landfill was not designed as a ‘containment’ site but was formed on the partially backfilled former ironstone quarry that raised the landfill base above the prevailing groundwater level. A gas abstraction system and flare stack was installed in 1990/91, but this suffered from flooding and was never effective. The infrastructure was replaced in 2004 with the system that is in use today. The leachate treatment plant, which includes three aeration lagoons, was installed around 1995 and has been upgraded since then to improve the aeration and automation. Additional combined landfill gas and leachate extraction wells were installed in 2008 and 2016. In March and April 2017, a new buried ring main approximately 1550m long was installed to replace the old pipework which in some places was restricting leachate flow due to the build-up of sediment within the pipework. The new ring main has been designed with valves to enable one half of the system to be isolated for maintenance and inspection purposes. The landfill is surrounded by a variety of land uses including agriculture/woodland, industrial/commercial and recreational, with extensive residential development being approximately 200m away. We propose to enter into one Contract for an initial period of thirty-six (36) months with the preferred provider, with an option to extend for twelve (12) months, making forty-eight (48) months in total.