May-June 2000

Landscape Waste Management Programs and Strategies

Landscape waste management practices that divert material from landfills are gaining attention in many US cities. These environmentally responsible alternatives challenge conventional waste management practices

Many communities are beginning to develop strategies to lengthen the life of landfills by diverting yard and organic waste for landscaping. There are many ways to process diverted waste for landscaping. One way is through composting, which involves the biodegradation of organic waste to humus. Approximately 25% of the wastestream can be safely composted, and nearly 15% of this amount is yardwaste. Recycling yardwaste back into the soil is an environmentally sound and economically viable waste management strategy. A variety of composting alternatives exists, including backyard composting, vermicomposting (or worm composting), and centralized composting

Other methods for processing yardwaste include chipping brush into small fragments that biodegrade rapidly. Typically a wood chipper reduces the brush and other yard debris to mulch, which can be used in various landscape applications. Mulching mowers also recycle plant and wood fiber into the soil.

National Programs

Across the country, municipalities are consistently implementing a variety of composting-related programs. For example, Los Angeles, CA, began promoting backyard composting in 1992 to stop landscape waste from entering the local landfill. The city utilizes the Master Composter training agenda and provides low-cost compost bins to citizens. Within the first four years of the program, the city sold 20,000 bins. Estimates indicate that for every household that actively composts, the city saves nearly $29. On the opposite coast, a similar program was promoted in West Palm Beach, FL, where Home Depot partnered with the local solid waste authority to promote home composting (Holden, 1996).

Vermicomposting is another form of composting that has been nationally promoted ranging from schools to municipalities. In Boston, MA, Josiah Quincy Elementary School maintains a rooftop organic garden. Students have added "red wiggler" worms to their compost bins, where the worms process leftover fruits and vegetables from lunches. The finished compost is applied to the rooftop garden (McGovern, 1997). In Orange County, FL, worms are being used to stabilize biosolids to a Class A pathogen standard (Riggle, 1996).

While backyard composting and worm composting target stopping waste at the source, the techniques are performed by individuals. By contrast, centralized processes address composting large amounts of landscape waste. First developed along the East Coast utilizing leaves, farmers in the West began large-scale composting nearly 30 years ago. Today, massive amounts of organic waste can be composted in a matter of a few weeks using a turned-windrow technology, whereby shredding and/or grinding of materials feed windrows. In Eaton, CO, a large-scale composter actively composts a wide range of materials, including yard and wood waste, tea-leaf waste, and brewery residuals (Cotton, 1996).

In Wartburg, TN, at the Morgan County Regional Correctional Facility, landfill disposal rates have dropped from 60-65 tons per month to 15 tons per month through a comprehensive recycling and composting program. Approximately 60% of the materials going to the landfill were diverted to a small-scale windrow. The compost is used to enrich surrounding farms. Therefore, cost savings occur from both disposal fees and fertilizer expenses incurred by area farmers (Walls and Buggeln, 1996).

In Arlington County, VA, a program started in 1996 allowed consumers to receive a rebate from the purchase of a mulching lawn mower. The program was so successful that 159 rebates redeemed during the first month exhausted available funds being used to support the program (Read and Korot, 1996).

The Wastestream Diversion Web

In Dallas/Ft. Worth (D/FW), TX, regional programs have responded to local needs, and various types of composting projects have begun. State objectives and funding have prompted many of these approaches. These objectives include recycling to extend the life of regional landfills and combating illegal dumping. Historically, funding has reached the local level through the regional planning agency (the North Central Texas Council of Governments), and funding priorities, as identified by the regional solid waste committee, have shaped waste management strategies.

Waste Management Survey

Regional statistics on yardwaste management were compiled for the D/FW area. For several years, D/FW cities have developed independent landscape waste management programs. The North Central Texas Council of Governments surveyed 42 cities in the region on landscape waste management practices. This survey was accomplished by mailing a questionnaire to the recycling coordinators for each city.

There was a 92.8% response rate to the survey (39 out of 42 cities). Survey results were entered into a database and organized question by question. Some of the key findings are presented below, in tables and maps for making comparisons across D/FW municipalities. Table 1 lists the number of cities in various provider and waste management categories.

Table 1. Cities Participating in Landscape Waste Programs in Dallas/Fort Worth

Figure 1 depicts 25 of the surveyed cities (64%) contracting with a provider to collect solid waste. Outside providers serve most of the western half of the study area, while Dallas and surrounding communities manage their own waste.

Nine cities compost solid waste or biosolids, representing 23% of those surveyed. Seven out of nine of these cities provide their own collection services, while the balance use a provider for collection services (Figure 2).

Twenty-five cities (nearly 64%) have participated in some form of community backyard educational composting (Figure 3).

Twenty-two cities, or 56%, collect brush separately from garbage (Figure 4). A large portion of the eastern region (nine cities or 23%) chips collected brush, while two cities (5%) to the north actively compost chipped brush. Seven cities chip and landfill (18%), and two cities simply compost collected brush (5%). Nineteen cities landfill all brush (49%).

Six cities, or 15%, have initiated bans on the collection of grass clippings. Many of these cities ask residents to leave the grass clippings on lawns, or dispose of them in separate biodegradable bags. A large majority of the cities that ban grass clippings also collect brush separately.

Discussion and Recommendations

The preceding maps clearly show that in cities using waste providers, landscape waste management practices are not widely used. In contrast, where cities operate their own landfills, there is greater benefit to extending the life of landfills, and landscape waste management is more widely practiced. This trend could be reversed if cities required providers to use alternative waste management practices. Creating more public demand for recycled wood fiber could provide an economic incentive for providers to divert waste from landfills.

Most of the cities in the study area have a keen interest in diverting yardwaste from landfills, as suggested by a 64% participation rate in the master composting/educational program and brush clippings map. These interests, however, are generally not being implemented when cities use outside providers for landfilling.

Yard and landscape waste account for nearly 15% of the MSW stream. Therefore, its diversion away from landfills could save a substantial amount of space, extending the life of regional landfills. For cities seeking to create new programs, combining elements of backyard composting education programs with centralized processing stations for chipping and composting would be an effective strategy. Cities could draw upon past successful projects in designing programs suited to their individual needs.

Regional partnerships that encourage city collaboration could result in cost sharing and help to increase the demand for composted materials. Such partnerships would also enhance regional education endeavors and promote regional composting facilities. Additionally, partnerships could help foster regional bans on grass clippings and policies requiring separate collection of brush, which could then be chipped and/or composted in centralized regional facilities.

As a result of an apparent perception of abundant landfill space, private collection providers generally landfill instead of recycle landscape waste in the D/FW region. Because many cities have access to only one landfill, programs encouraging the diversion of yard and landscape waste away from landfills are becoming more widespread. Comparisons of analysis from national programs to local ones in the D/FW area indicate similarities among all programs and all share common purposes. Regardless of similarities between programs, municipalities continue to operate independently of one another. Partnering to build new programs could facilitate more comprehensive agendas, which may be the most effective way to extend the life of regional landfills. Collaborative efforts addressing a regional problem with regional solutions have the potential to extend the operational life of landfills