Case Study of Successful Asphalt Shingle Recycling
Commercial Recycling Systems, Maine

Commercial Recycling Systems (CRS) of Scarborough, Maine has been successfully recycling asphalt shingles for over 7 years. The following information was compiled directly from Maine Department of Environmental Protection (MDEP) rules and licenses.

The CRS processing facility currently accepts shingles delivered in both roll-off and dump trailers containing 12-20 tons per load. Roofing products come from numerous towns, cities, and private roofing contractors in New England. In both 1999 and 2000, CRS processed over 10,000 tons of asphalt shingles into secondary materials. Collection of the shingles occurs at both municipal and commercial transfer stations, and through direct delivery to the CRS facility. An inspection is performed to make sure that incoming loads are comprised of shingles only and do not include any wood, flashing, or other debris. After inspection, the shingles are processed into the desired particle size at the facility with measures taken to both remove roofing nails and minimize asphalt dust. Dust is a potential nuisance to surrounding property owners and is minimized by a water mist. The processed shingles are then incorporated into various road construction materials such as HMA and cold patch at rates based on the product performance requirements. The use of the shingles in the construction materials replaces some or all of the virgin asphalt in the various grades of road building materials produced to meet Maine DOT product specifications (703.06).

MDEP has a Beneficial Use Section of the Maine Solid Waste Management Rules (Chapter 418 ). Among other things, the rule includes the following requirements:

• The material performs by meeting or exceeding the generally accepted specifications of the material it is replacing.
• The use is not disposal.
• The material is safe in the use proposed and will not pollute, create a hazard or create a nuisance.
• A license for recycling must be obtained and it requires an examination of risk as well as other application requirements.
• Annual reporting (See Maine Solid Waste Management Rules: Chapter 418 for more details)

CRS obtained a license to process and blend various recycled materials into the hot mix asphalt batching process in 1994 and most recently began to incorporate processed shingles into aggregate-based construction materials (e.g., ground shingles replace asphalt emulsifiers on a gravel road). In 1994, the use and distribution of asbestos in roofing materials was not well documented in Maine. To ensure no asbestos was present in the accepted shingles, CRS voluntarily sampled 118 incoming loads of residential shingles utilizing testing procedures as outlined in the Maine Asbestos Management Regulations Chapter 425, Section 10, to determine if any of the shingles or roofing material contained asbestos. A representative, composite sample of the shingles was taken using approved EPA Chapter 9 of SW-846, Test Methods for Solid Waste or ASTM methods.

• D4687 Guide for General Planning of Waste Sampling
• D6051-96 Standard Guide for Composite Sampling and Field Subsampling for Environmental Waste Management Activities
• D6044-96 Standard Guide for Representative Sampling for Management of Waste and Contaminated Media
• D6009-96 Standard Guide for Sampling Waste Piles

None of the residential samples contained asbestos fibers and the testing of the roofing was discontinued, with MDEP approval, on July 1, 1995. CRS continues to test commercial roofing, which is identified visually from worker experience and knowledge, to ensure asbestos is not present in the shingle material processed for beneficial reuse. Again, a representative composite sample may be collected and tested from any suspect material on a per-load basis.

CRS also completed other testing on the shingles to characterize them and for assessment of risk. Ground, composite samples were taken and analyzed for pH, percent of material passing through a 200 micron screen, total RCRA 8 metals, TCLP Semi-VOCs, total PAHs and TCLP VOCs. The results of the characterization indicated: 

1. Ground shingles are not a hazardous waste.
2. TCLP testing indicated that metals, VOCs, Semi-VOCs, PAHs and cPAHs are not readily leachable.
3. Approximately 2-4% of the shingle material is fine enough to pass a 200 micron screen and meet the Maine DOT specifications for use as construction road base materials.
4. There is a low concentration of the RCRA 8 Metals in shingles.
5. Some constituents of ground shingles, most notably cPAHs, exceed the concentration standards for de minimus risk as found in Appendix A of Chapter 418 (Maine Solid Waste Rules), and therefore required additional risk evaluation in the licensing process.

For further information from the State of Maine, contact:

Randy McMullin, Environmental Specialist
Maine Dept. of Environmental Protection
312 Canco Road
Portland, Maine 04103
207.822.6343
Fax 207.822.6303
Randy.L.Mcmullin@state.me.us

For further information from Commercial Recycling Systems, Inc. contact:

Commercial Recycling Systems, Inc.
2 Gibson Road
Scarborough, Maine 04074
207.883.3325
Fax 207.883.1121