COMPOSTING FOR CLASS “A”

Increasing uncertainties in land application programs and rapidly decreasing areas of suitable farmland, primarily adjacent to metropolitan areas, has resulted in a number of municipal agencies throughout the Country embarking upon composting to produce Class “A” biosolids. In addition, increasing costs associated with landfilling of solids and the desire to reuse biosolids in an environmentally responsible fashion has prompted the development of these successful composting programs. Communities such as Charlottesville, Virginia, Davenport, Iowa and Spotsylvania County, Virginia have all embarked upon successful aerated static pile biosolids composting operations over the past 20 years. This paper will provide information comparing capacities, capital & operating costs, odor management, and product marketing strategies currently used by these communities. The viability of these programs has been significantly improved through the use of ground brush/yard wastes as a bulking agent to offset bulking agent costs. Data regarding actual revenue generation through the sale of compost products and the net impact on operating and total annualized costs is presented. Case studies of each facility are provided showing the versatility of managing as little as six dry tons per day up to 28 dry tons per day of biosolids using variations in aerated static pile composting from partially enclosed to totally enclosed operations.