London airport runways cleared safely
Operating overnight, during the period when planes are not able to land or take off due to noise restrictions, sections of the runway were planed off before the contractor’s sweepers moved in to clean the runways prior to the new surface being laid in time for the first flights of each day at 6am.
At London City Airport, almost 30m3 of waste was swept from the runway each night, of which around only 25% comprised of solid materials - primarily stone, concrete, bitumen and dust. The Siltbuster dewatering and water treatment system enabled these solids to be separated and stored while the remaining waste water was treated and reused for dust suppression.
At Gatwick Airport, the dewatered solids component of the sweeper waste was disposed of off-site. However, the separated water had become highly alkaline due to its contact with recently disturbed concrete. To automatically detect and safely reduce the water’s high pH values, the plant used a Siltbuster pHD unit and DS1 sump tank, treating the water to such a high standard that it could be safely discharged to the airport’s sewer system.
Richard D Coulton, Siltbuster Business Unit Manager, said: “Our Siltbuster sweeper waste dewatering units were perfectly suited to these projects for several reasons. First and foremost, they were essential to ensure that the runways were successfully re-laid each morning and clear of any potentially dangerous debris before the first planes came in to land each day.
“Secondly, our RORO Sweeper Tip collected and held the waste at the airports during the night. This meant that it could be emptied and the waste transported to the local disposal sites during the day when they were open, with the Siltbuster serviced and ready to go again each evening. This reduced the number of lorry movements to and from the airports and, of course, saved a significant amount of money because sweepers were not leaving site full of rainwater.
“Finally, by using the Siltbuster systems, our clients were able to monitor and measure the exact amount of waste being collected and disposed of. This information is vital for the airport operators who are required to keep records of waste disposal for future audits.”
David Doherty, Site Agent for London City Airport’s contractor Lagan Construction, said: “We couldn’t have completed our project without an on-site sweeper tip and the Siltbuster system fitted the bill perfectly. It was surprisingly easy to maintain.”
