SUEZ site-seeing | Part 9 | Knowsley rail transfer station (Merseyside)

Merseyside Energy Recovery Limited (MERL) is a consortium of companies brought together with the purpose of helping Merseyside Recycling and Waste Authority (MRWA) manage household waste in the most sustainable way. The MERL consortium consists of three companies, SUEZ recycling and recovery UK, Sembcorp Utilities UK, and I-Environment Investments Ltd.

Together, the consortium has financed, built and now operates infrastructure to manage over 430,000 tonnes a year of residual waste from Merseyside and Halton, which is left over after recycling.

At the Knowsley site, the residual waste is bulked up and transported by rail to our newest energy-from-waste (EfW) facility in Wilton, Middlesbrough. Wilton is a 27 year contract, in partnership with SembCorp which manages 430,000 tonnes of waste per annum, worth £250m. The site began commissioning in June 2016, and opened just over a year later in September 2017, and is now operating at full capacity.

Knowsley’s automatic weighbridge allows pre-registered vehicles on to the site. Each day 110 vehicles drop approximately 1,600 tonnes of material. The transfer station is operated by 30 members of staff that work across three shifts 24 hours a day, five days a week.

The transfer station is a large former warehouse which has been repurposed to suit the demands of the contract. It is made up of a tipping hall and two bunkers. The bunkers can each cope with 4,000 tonnes of residual waste at time and each have their own overhead crane. The site also benefits from two hoppers and compaction units that feed the bulk containers and the rail link (all inside the warehouse!).

Ideally, the site will fill two trains each day transporting waste to our Wilton EfW facility. The train can fit just 20 per cent of its load capacity in the warehouse at any one time, so it has to constantly be loaded and then shunted forward for the next containers to be loaded until it is full. The staff have just a two and half hour window to load the train, using the four compactors and the three loaders to their full capacity! Each train can carry 900 tonnes of waste which is loaded into 66 containers. At the other end, the EfW facility will only accept materials that are already shredded, meaning any bulky waste must be processed before being loaded onto the train at Knowsley.

This is an incredibly clean site, as everything happens inside the warehouse. The local team is very switched on and is extremely busy ensuring materials are handled appropriately, and the tight turnaround times for loading the trains twice each day are met without exemption.