Heathrow Expansion

Heathrow Expansion 1

The Heathrow Expansion Programme is a £14bn project to construct a third runway, taxiways linking it to the rest of the airport complex, a new terminal building and satellite, additional stand areas, new airport gateways, carparks and other associated infrastructure. It will involve re-routing the M25, diversion of rivers and substantial earthworks to achieve.

Heathrow Expansion 1

Our Role

Our team were appointed to provide specialist landfill permitting advice in relation to the part excavation of the three existing permitted landfills and to prepare permit applications for four new landfills. To support the permit applications we designed the remedial works, the new landfills and carried out the associated environmental risk assessments. Our role in this project was wide-ranging and multidisciplinary including earthworks design, site investigation support, hydrogeological risk assessments, stability risk assessments, air quality assessment, design of landfill gas, leachate and odour control systems, environmental monitoring, regulatory compliance and advice on landfill tax.

Heathrow Expansion 3

Solution

Our primary role was to secure advance Environment Agency approval of the proposed works in advance of the project moving into the construction phase. This required the preparation of seven full permit applications, including three to allow the existing MSW landfills to be partly excavated and remediated and for four new engineered containment landfills to be developed alongside the proposed new runway. The new runway is to be constructed over the top of the existing three landfills posing some complex remediation and foundation design issues. The existing leachate and landfill gas control systems will be replaced and a new capping system installed. The four new landfills are to be constructed to EU/UK standards and were designed to take account of their close proximity to a working airfield with associated access restrictions.

Heathrow Expansion 2