Grass, leaves, and other wastes from lawns and backyard gardens account for an estimated 18% of the annual municipal waste stream. The percentage and composition of yard wastes varies widely from season to season. During the summer, grass can comprise up to 50% of municipal waste. Leaf waste can account for as much as 60-80% in the fall.
This massive, seasonal volume of yard wastes can put a strain on municipal garbage collection systems. Collection can require extra equipment that is not needed year-round and can increase personnel expenses.
Yard waste is a strain on disposal facilities. The large volume uses up valuable landfill space. The high moisture content of yard waste retards burning, which reduces the efficiency of waste-to-energy plants. Large incinerators built to handle peak seasonal rates of yard waste, may be oversized and less efficient at burning wastes the rest of the year. Burning yard wastes also puts a strain on pollution control systems.
Burning yard wastes at home causes air pollution from carbon dioxide and nitrogen oxide, is a fire hazard, and is a nuisance to neighbors.
Yard wastes are recyclable. Landfilling or burning them consumes a resource that is necessary to sustain life. Nature breaks down plant wastes through decay. The decomposed materials form a rich, dark soil called humus. Humus returns nutrients to the soil, improves soil texture, and promotes new plant growth.
Yard waste is composed of materials that, if left in their natural state, would form humus. Composting is an accelerated version of the natural decay process. Left to decay naturally, leaf waste can take approximately two years to form humus, depending upon climate conditions. With human intervention, making compost can take longer than one year or as little as 14 days.
In cultivated lawns and gardens, where this material is removed as waste, nutrients and conditioners must be mixed into the soil to promote healthy plant growth. Compost is made of the same materials and has the same properties as humus. When used as a mulch, it can modify soil temperatures, reduce erosion, control weeds and improve moisture retention.
Leaf waste must be separated from other residential wastes in municipalities required to recycle under Act 101 of 1988, the "Municipal Waste Planning, Recycling and Waste Reduction Act." Commercial, municipal and institutional establishments located within these municipalities also must separate leaf waste and store it until collection. Effective September 26, 1990, no waste disposal facility may accept shipments comprised primarily of leaf waste unless a separate facility has been provided for composting.
Act 101 encourages municipalities to establish leaf composting programs and provides recycling grants to help offset costs. More than 80 municipal leaf composting facilities are in operation in Pennsylvania. Leaf composting facilities that meet DEP guidelines do not require a permit to operate.
Leaf composting programs generally use the finished product to grow healthier plants on park, school and municipal grounds, and provide finished compost to residents, nurseries and landscapers. The principal benefits from composting leaf waste are producing a valuable soil amendment and avoiding disposal costs.
You can make a ton of compost at home in an area only 4' square. If you don't have a backyard, you can make smaller amounts of compost in plastic garbage bags. Backyard composting not only reduces the expense of buying fertilizers for gardens, landscaping and potted plants, it reduces municipal collection and disposal costs. Since many foods can be composted, including coffee grounds and eggshells, home composting can reduce food wastes as well as yard wastes. If you are interested in backyard composting, contact DEP for more information.
Bagging your clippings is not necessary to maintain your lawn. Leaving grass clippings on the lawn after mowing ensures that nutrients will be returned to the soil. Grass clippings are 20-30% protein, and usually contain about 4% nitrogen, 2% potassium and 0.5% phosphorus as well as all the necessary trace elements plants need.
When leaving clippings on the lawn, adjust your lawn mower to remove no more than one third (1/3) of the grass leaf surface at any one mowing. Any mower can be used, but one that mulches as it cuts is best. Use a slow-release fertilizer, water when necessary, and mow the grass at the proper height. Your county agricultural agent (check your local telephone directory) can provide general information on proper mowing heights, fertilizing and watering.
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Department of Environmental Protection
Bureau of Land Recycling and Waste Management
Dvision of Waste Minimization and Planning
Recycling and Markets Section
PO Box 8472
Harrisburg, PA 17105-8472
Hotline Number in Pennsylvania only: 800-346-4242
Please Print on Recycled Paper