Yard Trimmings
The recovery of landscaping wastes such as grass clippings, fallen leaves, and trimmings from bushes and trees has become very common as a municipal service. Local governments can divert these materials from landfills by offering drop-off sites and/or curbside collection of all yard trimmings not composted by homeowners. Drop-off sites tend to be better for residents that already deliver their household discards to landfills or transfer stations to avoid the costs of a curbside collection program.
Collection programs are typically provided weekly or biweekly to encourage participation by providing timely pickup and reducing the need for extended storage. Yard trimmings tend to be generated on a more sporadic basis with greater seasonal variance than traditional curbside recycling, so it is important to design collection routes accordingly. Container choice is an important aspect of a collection program because it can influence staffing and equipment requirements, as well as resident participation rates.
The following containers are used by different programs around the country:
Cans/Rolling Carts: higher upfront costs for one-time distribution, more durable
Bags: residents purchase, one-time use, could require removal for processing
Unbundled (in the street): collected using a specialized vehicle, reported to be popular with residents
Processing of residential yard trimmings is often performed by local contractors who operate composting facilities, or at landfill sites where the material is shredded on-site for alternative daily cover (ADC).
Commercial developments with large landscaped areas can develop their own composting programs on-site. These include parks, golf courses, corporate campuses, colleges and universities, and large multifamily residential developments. (see Compost Overview for details)
RATIONALE
The California Integrated Waste Management Board estimates that yard trimmings make up 15 to 30 percent of the state's total residential waste stream. The EPA estimates that 57 percent of yard trimmings were recovered for composting or grasscycled in 2000.
EFFORT REQUIRED
If a city can hire contractors from the local processing industry, then they would only be responsible for collection services and/or providing drop-off sites. If curbside collection is provided, the program model will have a large impact on the effort required. A city will have to consider container and collection vehicle requirements, route allocation and frequency, and consider varying collection vs processing trade-offs associated with sorting methods.
BENEFIT
- Divert valuable material from landfills
- Generate revenue from the sale of mulch and soil products
- Prevent release of methane from anaerobic decay
- Reduce the need for virgin lumber in mulch
- Save energy from extraction, processing, and transportation
RISKS
- Upfront investment in containers, hauling vehicles, and facilities
- Improper sorting of materials
- Lack of participation
ACTION AGENTS
- Environmental Management Department
- Solid Waste Management/Recycling Departments
- Public Works Department
- Parks Department
COST
Curbside collection is more expensive than drop-off, but often is necessary to achieve high participation and diversion rates. The increased operational costs of curbside collection programs can be offset by: decreased disposal costs (tipping fees), increased landfill life, potential revenue from compost and/or mulch sales.
Using Riverside, CA as an example, green waste is delivered and tipped at a $20-per-ton savings when compared to trash.
Material (other than earth) that is placed on the surface of an active solid waste landfill at the end of each operating day to control fires, odors, blowing litter, and scavenging.Waste disposal sites for solid waste from human activities.Charged by a landfill for disposal of waste, typically quoted per ton.A mixture of decayed plants and other organic material that is used to enrich soil with nutrients.The collection, reprocessing, marketing, and use of materials that were diverted or recovered from the solid waste stream.The ability or potential of a physical body to do work. The most common forms of energy are heat, light, mechanical (moving parts), and electrical.
