"Innovations" Case Studies: New Uses for Old Tires

Summary

Overview

Used tire disposal and recovery is a great challenge for local governments.  Unlike most types of solid waste, used tires cannot be landfilled whole. Discarded tires present a variety of hazards for the environment and public health, including air and water pollution, disease-carrying vectors, and potential fires at both illegal dumps and regulated tire stockpiles.

Californians produce 31 million discarded tires annually, representing 3 percent of the municipal waste stream by weight.  California imports another three million tires from nearby states.  Only about 40 percent of tires are diverted to end uses such as reuse, retread, crumb rubber, and energy recovery.  The State must find uses for the remaining 60 percent currently stockpiled, illegally dumped, or shredded and landfilled.

New uses for old tires can reduce waste, cut costs, and improve the quality and safety of public works projects in the following ways:

• Providing rubberized asphalt for road construction.  Los Angeles County has created the South California Rubberized Asphalt Concrete Technology Center to promote the use of rubberized asphalt concrete (RAC) throughout the state.

• Providing tire shreds and rubber products for civil engineering applications.  The state of Maine has made lightweight fill the predominant use for tires removed from the state’s abatement piles.

• Providing crumb rubber products for playground renovations and molded products.  Communities like Torrance and Garden Grove, California, are using tires when replacing playground equipment to meet new State and federal safety laws.

Costs, Economics, and Benefits

Costs associated with tire management programs vary depending on the requirements of the jurisdiction.  Costs generally fall into the categories of collection, processing, and end uses.

Collection costs depend on the type of program operated, averaging from $1.82 to $2.26 per tire.  Processing costs vary depending on the specifications, but crumbing a tire typically costs about $2.40 per tire.

Use of recycled-content tire products can dramatically reduce costs for public works projects or local government needs in the following ways:

• Tire crumbs for paving can result in an initial cost savings of $22,000 per lane mile.  Ongoing savings from reduced maintenance and a longer replacement life cycle add dramatically to the initial savings.

• Rubber mats or molded rubber products typically are comparable in cost to rubber products that have no recycled content.

• Civil engineering projects have shown that tires can be cheaper than typical lightweight fill.

The CIWMB offers tire recycling grants to local governments for collection programs, use of paving material, and playground/track covers.

• For collection programs, the CIWMB provides matching grant funds for public education, staff time, and some transportation and processing costs.

• CIWMB has provided grants to local government and school districts for the purchase of rubberized playground mats.

• Rubberized asphalt grants are available for determining the potential use, quality assurance and quality control, and costs associated with rubberized asphalt.  Grants from the CIWMB are available through the Los Angeles Rubberized Asphalt Technology Center on first-come-first-serve basis and are based upon the tonnage of material used.

Tips for Replication

• Communication between all stakeholders involved in a project is critical, including developing a strong working relationship with both tire shredders and public works contractors.

• Private contractors will be the key in preparing tires for use as well as applying them in most projects.

• Most programs are public/private partnerships. Equipment costs associated with shredding, crumbing, and blending typically prohibit local governments from setting up a cost-effective in-house program.

• Most local governments do not have the immediate volume of work to use their present supply of waste tires. Working in a cooperative with other local jurisdictions can be more efficient.

• Private contractors are often better equipped to process and supply tires for construction projects.

• Other opportunities for local governments to support increased tire recovery and end use include:

• Promoting the use of retreaded tires on fleet vehicles.  Local governments and private operators of vehicle fleets can develop plans to focus both maintenance and purchasing routines to extend tire life and use retreads.

• Supporting the purchase of new tires containing recycled content.

• Supporting the purchase of recycled rubber products, particularly mats and sport floorings.

CIWMB Publications

CIWMB publications are available from the Board’s online Publications Catalog.

Credits/Disclaimer

Pursuant to contract (IWM-C8028) with the University of California at Santa Cruz for a series of 24 studies and summaries, Californians Against Waste Foundation (Sacramento, CA) researched and wrote this summary for the California Integrated Waste Management Board.

The statements and conclusions in this summary are those of the contractor and not necessarily those of the California Integrated Waste Management Board, its employees, or the State of California. In addition, the data in this report was provided by local sources but not independently verified. The State and its contractors make no warranty, express or implied, and assume no liability for the information contained in this text. Any mention of commercial products, companies or processes shall not be construed as an endorsement of such products or processes.

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Last updated: December 28, 2007