Landfill Design

REC recommends that the Environment Agency are consulted at an early stage about proposed new facilities, so that a strategy for the investigation, monitoring and design of the site is carried out in accordance with best available techniques and the most cost effective manner. REC's assessment of the suitability of a potential landfill site would examine it’s geologically and hydrogeological characteristics and would investigate:

· Geological conditions.
· Geological structure.
· The materials geotechnical properties.
· The sites permeability characteristics.
· Its diffusion/attenuation properties.
· Its existing inherent chemistry.
· The three dimensional distribution of lithologies.
· Its cation exchange capacity.

The hydrological and hydrogeological properties are vital considerations in the design of the landfill containment solution. The assessment must contain a detailed risk assessment for the possible migration of List 1 and List 2 substances to any groundwater receptors. REC would devise a monitoring regime in the early stages of a site's design to establish the base line chemistry of the site and the location of any receptors. This helps evaluate any potential impact during the lifetime of the landfill. During the design of any new landfill facility REC would examine the:

• Maximum depth of cell bases.
• Geotechnical characteristics of lining materials.
• Configuration of basal and side wall liners including geotextile protectors.
• Availability of any suitable liner materials and any subgrade.
• Maximum depth of cell bases.
• Haulage routes to individual cells.
• Availability of materials for use as daily cover.
• Distance to gas migration receptors.
• Stability of existing quarry sidewalls.
• Extent of drainage network on base and sidewalls.
• Configuration of cap drainage and cover system.
• Restoration design of individual cells.
• Leachate treatment facility design.
• Odour mitigation measures for the leachate treatment plant and for waste faces.