SC22085 - North Farm Environmental Works

Tender description

Kent County Council (KCC) is the largest local authority in England covering an area of 3,500 square kilometres. It has an annual expenditure of over £1bn on goods and services and a population of 1.6m. The Council provides a wide range of personal and strategic services on behalf of its residents, operating in partnership with the NHS Kent and Medway Clinical Commissioning Group, 12 district councils, and 289 parish/town councils. KCC consists of four directorates: • Adult Social Care and Health; • Children, Young People and Education; • Growth, Environment and Transport; and • Strategic and Corporate Services. This service is being commissioned on behalf of the Growth, Environment and Transport directorate. KCC's North Farm Closed Landfill Site (CLF) is situated on the edge of the North Farm Retail Park, Tunbridge Wells. The Site is bounded by woodland to the north, a railway line and woodland to the west. Residential property is present to the south west of the Site. North Farm Retail Park is present to the east and south, along with Southern Water's waste water treatment works and the KCC Waste Transfer Station (WTS) and Household Waste Recycling Centre (HWRC). The Somerhill Stream runs along the northern and eastern Site borders. The primary work objectives are to reduce the amount of water discharged to the Southern Water Wastewater Treatment Works and to maintain or improve the gas infrastructure system to enable the possible future electricity generation through a gas engine. These objectives will be met through provision of an impermeable Geo-composite Clay Liner (GCL) with a covering protection layer of soil to the landfill cap, creation of a detention basin, and construction of a replacement gas infrastructure network. The impermeable clay liner will restrict infiltration of surface water through the landfill cap reducing leachate volumes. Surface water run-off will be captured through filter drains and directed towards the detention basin for discharge to the surrounding surface water bodies. The landfill cap will have the secondary effect of reducing atmospheric ingress and waste moisture content which together with the improved gas infrastructure network should improve the quality of gas extracted and the overall efficiency of the system.