Site

The composting site has been operational since January 2003 and is capable of processing up to 50,000 tonnes per annum of green waste. The site is at Beenham near Reading at the heart of the Thames Valley and is also the location of one of our Materials Recovery Facilities.

The site is one of the few large-scale in-vessel composting sites in the country. Grundon chose the Pod system as it eradicated many of the problems associated with the traditional method of open windows, such as odour and litter.

Process

Once the waste is received in the reception area, it is checked for contamination and then shredded and mixed ready for placing in the Pods. The reception area consists of a large concrete pad, this is a sealed surface with all run-off draining to two storage lagoons.

The Pods are made of LDPE plastic, are 60 metres in length and are 1.5 metres in diameter. The shredded waste is placed in these pods using a specialised machine, which threads an aeration pipe through the mass of shredded green waste.

Temperature is constantly monitored during the composting process by the use of temperature probes that are inserted in the vent valves, which are installed along the Pod. The probes are attached to data loggers, which record the information before it is downloaded to a laptop computer. The analysis of this temperature allows us to decide whether the airflow needs adjusting to maintain the correct temperatures. By ensuring the correct temperatures are achieved and maintained it ensures an efficient process with weed seeds and pathogens being destroyed.

After approximately 10-12 weeks the pods are ready to be opened, the compost is removed and taken to the screening area. The material can be screened to a range of sizes but generally a product of 0-16 mm in size is created for use as a soil conditioner.

Quality

From day one of operations it was the aim of Grundon to develop a site using a modern system to produce a quality product. Systems and procedures were developed to ensure that there were stringent controls in place, so that we could be confident that the product produced was of the highest quality.

This quality has been recognised with the site being awarded the certificate of compliance for BSI PAS100:2002 for the compost produced. It was the first in-vessel site ever to achieve this accreditation.

Product

The soil conditioner being produced is used by a number of landscape gardeners, nurseries and alike. The product is sent away for analysis to ensure that it meets the standards set down under PAS100, this ensures that it is to be free of physical contaminants, viable weed seeds and pathogens. A product data sheet is available on request.