Drainage engineers from the national drainage and maintenance specialist's depot at Sevenoaks, in Kent, are carrying out the work at the site of the former Kingsnorth Power Station in Kent.
Energy company E.ON has given demolition specialists Brown and Mason the task of decommissioning the 2,000 megawatt power station, which ceased generating electricity in December 2012.
Lanes Group teams have carried out CCTV surveys on surface and foul water drains. They have also cleaned eight drainage interceptors, including two fuel oil interceptors, two pump house interceptors, and three car park interceptors.
Neville Pantin, contract manager for Brown and Mason, said: "Lanes Group has done some excellent work for us. They've supplied some very detailed drainage survey reports which will help us plan our demolition work.
"Cleaning out the drain interceptors was not easy. A number of them were heavily contaminated with oil, which was difficult to work with. But they stuck to the task, and worked professionally and safely."
Lanes deployed a jet vac tanker team and a two-person CCTV drainage survey team to carry out the work on the site on the Hoo peninsular at Medway.
Most of the interceptor waste could be taken off site to be disposed of at an authorised waste management facility. A quantity of oily sludge was stored on site, ready to be disposed of by Brown and Mason.
John Gilbert, area development manager for Lanes Sevenoaks, said: "Working on former energy generation sites like this present a range of challenges, especially during an active decommissioning and demolition programme.
"These include managing high volumes of contaminated and hazardous waste, safe access to worksites, working on extensive and often unmapped drainage systems, and managing the scope and size of the task while maintaining the quality standards expected by both Lanes Group and the client.
"We have worked on many similar energy generation sites, including nuclear power sites, so have the experience, skills and equipment needed to complete these complex programmes of work."
Lanes Group works with many other national and international companies to facilitate their site exit strategies, including petro-chemical and pharmaceutical firms.
They select Lanes Group because the disposal and redevelopment process is often long, complex and commercially sensitive, so they need to work with drainage contractors who they can trust and can build long-term relationships with.
Kingsnorth Power Station was built between 1963 and 1973 on the site of a former World War I airship base. It was commissioned in 1975, providing electricity for the London power grid.
The power station, which could also burn oil, was closed to meet UK and EU commitments on greenhouse gas reduction. These included compliance with the EU Large Combustion Plant Directive, which has required the closure of power stations without flue gas desulphurisation systems.