Quality compost from source separated organic material and biosolids in East Prince County, Prince Edward Island

Source separated organic material from 13,000 households and 1000 businesse s is mixed with biosolids from a primary sewage treatment plant to produce a top quality compost product. The organic material is shredded and then co mposted using an open windrow process without forced aeration. The active c omposting detention time averages 40 days inside a covered compost building . The compost is then cured outdoors on an asphalt pad with a curing detent ion time of up to six months. For the past four years this system has proce ssed an average of 9000 tonnes of raw materials a year into 5000 tonnes of finished product. The finished compost is screened prior to marketing using a mechanical power screen unit. The composting process is monitored regula rly for temperature, oxygen, pH and moisture content. Representative sample s of the compost have been tested for heavy metals and nutrients since the site was commissioned in December 1994. The average concentration for all h eavy metals analysed, except for copper, meets the requirements of Category A compost in the Canadian Guidelines for Compost Quality.