During the main growing season (March to October) we handle over 150,000 tonnes of green waste. The material is collected from households and taken to our dedicated composting facilities where it is shredded and stored in batches, known as windrows.
Week 2 – 4
The windrows are monitored and turned regularly, using mechanical plant, to maintain optimum temperatures and moisture to encourage the sanitisation and composting process.
The compost is still turned regularly until it enters the stabilisation process. This happens when microbial respiration does not significantly resurge under altered conditions e.g. changes of moisture, oxygen levels or temperature. The rate of carbon dioxide and heat release decreases with increased stability.
Week 9 – 11
The green waste is then put through a trommel, which is a large rotary drum that screens and separates larger material, such as branches and bits of wood. It is then fed through a wind sifting machine, which uses a continuous jet of air to further screen the material and extract any litter. Any larger material is fed back into the start of the process and mixed with the green waste.
At the end of the composting process the material is separated into two different grades. The resulting Yorganics compost (30mm and 10mm) is then ready to be bagged, or sold in bulk, to be used by farmers in agriculture, horticulturists or by householders in their gardens.