Tour of Shrewsbury Garden Waste Composting operation

A bunch of us volunteers from Shropshire Master Composters recently went to take a look around the farm near Shrewsbury where the Council sends all our garden waste for industrial scale composting.

The site on Lower House Farm, Cardeston, near Ford is run as a commercial operation as Agripost Ltd. by farmer Mark Gethin, who diversified into composting following the devastation of the foot and mouth crisis of 2001.

The site manages over 10,000 tonnes of mainly municipal waste every year.  Predominantly this is garden waste (and cardboard) which is collected from our household green wheelie bins from all around the Shrewsbury and Atcham area.  There are also some inputs from the Household Recycling Centre - the tip - in Battlefield and also from some local contractors who bring commercial waste to the site for a small fee.   

All waste delivered to the site first goes over the weighbridge and is then tipped onto the concrete pad for inspection. The site charges a gate fee per tonne for waste to be bought onto site and is run as a profitable commercial business.

All the waste has to be screened for quality control and it gets hand picked to remove any obvious visible contamination like plastic bags which some idiots seem to think is "compostable garden waste" and insist on regularly adding to their green bins.

The "cleaned" waste then gets loaded into this massive industrial shredder (below) which can shred over 10 tonnes an hour! 

The resulting output which is now much less coarse (generally shredded to about 100mm particle size) then gets piled into huge pyramid shaped mounds called "windrows".  This may look like a messy heap, but theres actually quite alot of intelligent design gone into it because their natural shape aids the air flow through the piles and the natural heat created by the decomposition process helps create convection currents which drive air through the mounds helping to keep the whole operation aerobic.  

The windrows get systematically turned at regular intervals using a JCB.  The piles get extremely hot as they rot, visibly steaming.  The microbial activity which drives this takes place in as little as 2-3 months, far quicker than you would get in a home compost bin.

The finished product, which is certified to PAS100 standard is used on site as a soil conditioner.  Once seived to remove large particles its a fine looking brown earthlike product which is excellent for the soil

For more information on this site visit www.agripost.co.uk