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The material is delivered to the composting facility at Alfreton where it is tipped in the receiving area. When the site has sufficient amounts of garden waste the material is fed onto a conveyor belt by a mechanical grab.

The conveyor belt feeds the garden waste into a shredder.

This shreds the material into a fine matter.

This shredded material is then formed into a 'windrow' (where the green waste is raked to provide optimum conditions) which is triangular in section, roughly three metres high, three metres wide and about 40 to 50 metres long. Each windrow receives a unique number so that its progress throughout the process can be carefully sampled, monitored and tested.

Composting uses air, water and living organisms to turn waste into a useful product, the most important variables in the process being oxygen, temperature and moisture. Windrow temperature is recorded daily and when 55 degrees Centigrade is reached (normally after two to three days) then maintained for three consecutive days the whole windrow is mechanically turned and mixed to encourage the aerobic (with oxygen) process.

At this stage the material gets very hot, temperatures as high as 70 degrees Centigrade have been recorded. This is necessary to destroy weed seeds and unwanted bacteria.

Moisture is a vital ingredient in composting. Too little and the chemical reaction cannot take place; too much and the spaces which should be filled with air become waterlogged. Therefore the moisture content is measured, controlled and adjusted when necessary throughout the process.

Aeration is achieved by turning the windrow several times in all and after approximately eight weeks the composting process slows down. Most of the waste has then turned into soil improver at this stage and the volume of the windrow has been reduced considerably. The material is then left undisturbed for a further three to four weeks for an initial ‘maturation period’ during which the micro-biological and chemical activity is significantly reduced.

The composting site we use, like many others in the UK, use the windrow method. Under the animal by-products regulation that was established after the Foot and Mouth crisis, all food scraps collected for composting have to go through a special process called 'in-vessel composting', which at present, is not available in this area.