Odour and Composting Process Control Procedure

Purpose. Describes how the Windsor composting process is controlled and monitored so that pathogens are destroyed, product meets the standard and odour is kept below the licence limit at the boundary.

1.Scope

This procedure applies to the receival, shredding, windrow construction, aeration, turning, maturation, screening and release of compost at Windsor. It must be read with the odour management plan and the licence conditions in the legal obligations register.

2.Receival

Food organics must be incorporated into a windrow or covered with a carbon rich layer within four hours of receival. Receival must stop when the covered receival area is full or when the weather conditions in the odour management plan apply. The floor inspector must record contamination in the inbound loads register and remove plastics, glass and metals before shredding.

3.Windrow construction and pasteurisation

Windrows must be built to the recipe for carbon to nitrogen ratio and moisture and must be recorded with a batch number. Each windrow must reach the pasteurisation temperature and hold it for the number of days and turns required by the product standard. Temperature must be measured at the points and depth in the work instruction at least daily and recorded in the sample and monitoring register.

• Core temperature of at least 55 degrees for the required period
• Minimum number of turns during the pasteurisation period
• Moisture between 45 and 60 percent
• Oxygen maintained above the minimum by forced aeration or turning

4.Odour control

Turning must be scheduled in the morning when the forecast wind is away from sensitive receivers and must not be carried out during the conditions listed in the odour management plan. Daily boundary odour observations must be recorded. Leachate must be collected in the lined pond and reused on windrows or removed by a licensed contractor.

5.Product testing and release

Each batch must be sampled after maturation and tested for pathogens, contaminants, physical contamination and maturity. Product must not be released until the results pass the standard and the Organics Facility Manager records the release in the sample and monitoring register.

6.Non-conformance

A windrow that fails to reach temperature, a product batch that fails testing or an odour complaint that is confirmed must be recorded as a non-conformance and investigated. Failed product must be reprocessed or disposed of through a licensed facility and the quantity recorded.