Once a week, the county collects yard waste at the curbs of homes in Severna Park. The bags of leaves and bundles of branches are loaded on a recycling truck, but where does this material go once it is collected?
Fortunately, yard waste from our area is not dumped in a landfill. It is transported to the Western Branch Composting Facility in Upper Marlboro which is managed by Prince George’s County and operated under contract by Maryland Environmental Services. It is there that over 80,000 tons of yard waste from Anne Arundel County and Prince George’s County residents are processed into mulch and compost each year.
The composting process comprises a large part of the facility's operations. When yard waste arrives, it is loaded into a large machine, ground up, and deposited in long, narrow piles called windrows. At this point, the composting process begins and usually takes about nine months to complete. During this time the material in the windrows is turned over about twice a week during the spring and summer by another machine called a scarab, which is designed just for this purpose.
Although it is a commercial operation, the Western Branch Composting Facility must, like a home gardener, maintain a 25:1 carbon-to-nitrogen ratio of organic material in order for the composting process to be successful. Leaves, which are the main source of yard waste in the fall, are a good source of carbon. Grass clippings are added in the spring to provide the nitrogen needed to ensure the yard waste decomposes properly.
After the material in the windrows has completed its nine month decomposition process, it is moved to a curing pile where it is allowed to finish decomposing for another three months. Once the compost has finished curing, it is spread out, allowed to dry, and then put through a screen to remove any particles larger than 3/8 of an inch in diameter.
When this process is completed, the compost is ready to be sold in bulk to wholesalers and retailers where it is marketed under the name Leafgro, which is used by home gardeners and landscape professionals as a soil amendment.
The Western Branch Composting Facility sells approximately 50,000 cubic yards of Leafgro each year to wholesalers with the proceeds from the sales used to cover the production costs of the operation. Maryland Environmental Services also operates a similar facility in Dickerson, MD. The Montgomery County Compost Facility produces and packages Leafgro for retail sales as well as another organic product, ComPRO, which is a compost product for use on lawns.