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Environmental Issues Associated With Asphalt Shingle Recycling

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					 Environmental Issues Associated
  With Asphalt Shingle Recycling

Presented at the 3rd Asphalt Shingle
         Recycling Forum
         Chicago, Illinois
         November 1-2, 2007
• Jon T. Powell, E.I.
• Innovative Waste Consulting Services
• Gainesville, Florida
            Project Background
• Initial involvement to help develop
  http://www.shinglerecycling.org
• Compiled a white paper on behalf of CMRA and EPA
  that:
  – Summarized two environmental questions/concerns raised
    regarding shingle recycling
  – Collected data from recyclers in the US
  – Evaluated analytical data
      • Published
      • Recycler-supplied
  – Incorporated input from CMRA, EPA, UNH
• Will keep updating available analytical data as
  it is collected
           Presentation Outline
• Background
• Overview of Asphalt Shingle Recycling
• Environmental Questions or Issues
   – Asbestos
   – Polycyclic Aromatic Hydrocarbons (PAHs)
• Conclusions
• On-going research in Florida
                   Background
• Asphalt shingles are the most common roofing
  material in North America
• Great market potential for recycling
• Approximately 11 million tons of asphalt
  shingle waste is generated per year
  – Post manufacture (scrap): 1 million tons
  – Post consumer (tear-off): 7-9 million tons
Typical Composition of An Asphalt
            Shingle
                                    Granular/aggregate

                                   Waterproofing asphalt

                                   Base (fiberglass or organic felt)


                                    Waterproofing asphalt

                                     Back surfacing

      Component              Organic Felt             Fiberglass Mat
    Asphalt cement             30-36%                    19-22%
           Felt                2-15%                      2-15%
        Mineral
                               20-38%                    20-38%
  granules/aggregate
 Mineral filler/stabilizer     8-40%                      8-40%
       Asphalt Shingle Recycling
• Typical Management




                             Landfilling


                       Recycling
           Asphalt Shingle Recycling
• Markets
  –   hot mix asphalt (HMA)
  –   temporary roads or driveways
  –   dust control on rural roads
  –   cold patch
  –   aggregate road base
  –   new shingles
  –   Fuel/energy supplement
  –   landfill cover
  –   mulch


           http://useit.umaine.edu/images/maingallery/msc9.jpg
Post-Consumer Asphalt Roofing Shingle
          Processing Facility
      Raw Material

Asphalt shingles is dropped
 off by roofing contractors.
Horizontal mill for size reduction
Trommel Screen
Overhead magnet used for the “under” and “over” streams
Unders – Used as HMA additive   Overs – used as covering and
                                paving material for unpaved roads
                                     Ferrous
                                      Metal



                                     Overhead
                                                Fine
              Excavator               Magnet    ASR


   Asphalt                 Trommel
                Shredder
   Shingles                 Screen


                                     Overhead   Coarse
                                      Magnet     ASR

Basic Layout of Post-Consumer
        Asphalt Shingle               Ferrous
      Processing Facility              Metal
Environmental Concerns

                         ASBESTOS




                          PAHs
    Possible Exposure Pathways
                                         PAH leaching?
Release of
                  PAH emissions?
Asbestos?


             or                    or




 Grinding             HMA               Pavement, mulch, etc.
                Health Impacts

• Asbestos
  – Lung cancer
  – Mesothelioma



• PAHs
  – Cataracts, kidney and liver damage
  – Some PAHs are identified as carcinogenic
            Pathways of Possible Exposure
               at Recycling Operations




Generator               Processing Facility
                        (storage, grinding)




Most likely pathways of exposure
            Pathways of Possible Exposure
               for Recycling Operations
                                                   Air Emissions
                                                         PAH

                           Asbestos
                         Air Emissions
                                                     Use in HMA



Generator              Processing Facility
                       (storage, grinding)


                                                     Direct Use
                         Water Emissions
                                 PAH
                                              Water            Human
                                             Emissions         Contact
                                               PAH              PAH
Regulatory pathways of concern
ASBESTOS
          Types of Asbestos

•   Chrysotile
•   Amosite
•   Crocidolite
•   Tremolite
•   Actinolite
•   Anthophyllite
                Was Asbestos Widely Used?
                                  Years
      Manufacturer                                                               Product
                               Manufactured

Barber Asphalt Corporation           NA                                 Asphalt-asbestos roof felt

   Carey Manufacturing
        Company
                                     NA                  Asphalt-asbestos shingles, asbestos finish felt, mastic

 The Celotex Corporation     1906 through 1984            Asphalt roof coating and other miscellaneous materials

                                                       Roof paint, roll roofings with asbestos-containing base sheets,
 Fibreboard Corporation         1920 to 1968
                                                   caulking compounds, plastic cements, taping and finishing compounds

 General Aniline and Film
                                     NA                                      Roofing asphalt
      Corporation

Johns-Manville Corporation   1891 through 1983
                                                    Asphalt-asbestos shingles, rag-felt shingles, fibrous roof coating,
                                                                      shingle tab cement, roof putty
    Kaylite Company                  NA                           Asbestos surface coating for shingles
National Gypsum Company      1941 through 1981                             Roofing and shingles
    Monroe Company                    NA                        Asbestos surface coatings for shingles
                             Early 1930s through
Rhone-Poulenc Ag Company                                        Adhesives, coatings, sealants, and mastics
                                     1976
  United States Gypsum
                             1930 through 1977                                Paper and felt
        Company
 Asbestos roof shingles
 (transite) were fairly
 common; however, this
 is not the same thing as
 asphalt shingles.

 There were also a lot of
 other roofing products
 that used asbestos.




http://www.printedpages.net/ASBESTOS.html
                                                                           “This roofing is made by crushing
                                                                           solid asbestos rock and
                                                                           compressing the long fibres into a
                                                                           dense, homogeneous felt. Several
                                                                           layers of this rock are then
                                                                           permanently cemented together
                                                                           with nature’s greatest water-
                                                                           proofer, Trinidad Lake Asphalt,
                                                                           making a light-weight roofing that
                                                                           is virtually a solid sheet of pliable
                                                                           stone.”
http://cgi.ebay.com/1913-JOHNS-MANVILLE-ASBESTOS-ROOFING-AD-LIKE-SO LID-
ROCK_W0QQitemZ120168796596QQihZ002QQcategoryZ37831QQssPageNameZ
WDVWQQrdZ1QQcmdZViewItem
   Asphalt Shingle Testing Results for
               Asbestos
• Data from processors in Maine, Iowa, Florida,
  Missouri, Minnesota, and Massachusetts
• Data available for 27,694 samples collected
  – 18 detections asbestos content <1%
  – 408 detections asbestos content >1%
  – Overall, asbestos detections in 426 samples
     • Approximately 1.53%
            Asbestos Summary
• Asbestos was used in the manufacture of asphalt
  shingles and asphalt-containing roofing
  materials in the late 1800s, continuing through
  to the 1980s.
• Asbestos phased out as component of asphalt
  shingles in the early 1980s.
• Data on asbestos content in asphalt shingles is
  very limited.
• Service life of an asphalt shingle is around two
  decades, +/-.
             Asbestos Summary
• It is common practice in re-roofing to install new
  shingles directly on top of old ones.
  – As such, a load of post-consumer asphalt shingle waste
    may contain multiple layers of asphalt shingles of
    varying age.
                                       Asbestos Summary
       • Analytical results of over 27,000 asphalt
         shingle samples indicated that about 1.5% of
         all samples detected asbestos.
               – Many asbestos detections
                were caused by other materials
                such as mastic that were attached
                to the samples.



http://cgi.ebay.com/1956-Insul-mastic-Co-Insulation-Catalog-Asbestos_W0QQitemZ330173307503QQihZ014QQcategoryZ4259QQcmdZViewItem
           Asbestos Summary
• Despite the interference in the samples from
  the presence of mastic, the limited number of
  asbestos detections was consistent with the
  fact that asbestos was mostly phased out in
  the 1970s and that the typical reported
  service life for asphalt shingles is around 15-25
  years, although effect of new shingles being
  installed on old ones may impact detection.
           Asbestos Summary
• Obtaining/sourcing uncontaminated material
  should further reduce incidence of asbestos in
  samples
  – Some states restrict where the shingles can come
    from
PAHs
What are Polycyclic Aromatic Hydrocarbons
                  (PAHs)?
• A group of over 100 different chemicals
• Formed primarily during the incomplete burning
  of coal, oil and gas
• EPA identifies 7 PAHs as probable human
  carcinogens
  – Benz(a)anthracene, Benzo(a)pyrene,
    Benzo(b)fluoranthene, Benzo(k)fluoranthene,
    Chrysene, Dibenzo(a,h)anthracene, Indeno(1,2,3-
    cd)pyrene
               PAH Issues Raised
• Some have raised question of whether PAHs
  should be a concern when recycled asphalt
  shingles are:
• Ground up and used as road base
• Ground up and used as mulch
  – Leaching?
  – Direct Exposure?
• Used in HMA
  – Air emissions?
                     PAH Summary
• Asphalt shingles naturally contain PAHs.
• A leaching study on discarded asphalt shingles indicated
  that PAHs did not readily leach PAHs.
• Related studies on virgin roofing asphalt, reclaimed
  asphalt pavement, and run-off from asphalt pavement
  indicated PAH concentrations below the laboratory
  detection limits.
   – However, since that study some acceptable levels have
     decreased
   – Additional data are required to detect these samples at lower
     concentrations
               PAH Summary
• PAHs are emitted during HMA production
  – Pollution control equipment reduces PAH
    concentrations
• The effect of using post-consumer asphalt
  shingles in HMA on PAHs is unknown
• The use of post-manufacture asphalt shingles
  is permitted in some states
• A study in Texas investigating the issue of PAH
  emissions in HMA production has not yielded
  any data to date
             PAH Summary
• It is not anticipated that clean,
  uncontaminated asphalt shingles would cause
  PAH emissions to be significantly different
  than virgin asphalt
     Recommendations to State
           Regulators
• You can obtain a copy of our White paper,
  which provides recommendations for
  information and demonstrations a facility
  should make to recycle post-consumer asphalt
  shingles as part of permitting
Ongoing Research
RISK ASSESSMENT OF THE REUSE
AND DISPOSAL OF SEVERAL
ASPHALT WASTE MATERIALS
                  Overview
• University of Florida Department of
  Environmental Engineering Sciences
  – Solid and Hazardous Waste Laboratory
• Objectives:
  – Measurement of PAHs using instrumentation with
    lower detection limits (shingles and RAP)
  – Risk-based analyses of PAHs and other chemicals
  Polycyclic Aromatic Hydrocarbons (PAHs)
Parameter             FL-GCTL (µg/L)   Parameter                FL-GCTL (µg/L)

Acenaphthene                 20        Chrysene                        5

Acenaphtylene                10        Dibenz[a,h]anthracene          7.5

Anthracene                  2100       Fluoranthene                   280

Benz[a]anthracene            4         Fluorine                       280

Benzo[a]pyrene              0.2        Indeno[1,2,3-cd]pyrene         7.5

Benzo[b]fluorathene          4         Napthalene                     6.8

Benzo[ghi]perylene           10        Phenanthrene                    10

Benzo[k]                     4         Pyrene                         210
   Leaching Test & Analysis in UF
                         Sample Collection
                         (RAP & asphalt shingles)


                         Leaching Test (SPLP + TCLP)



                           Analysis leaching solution




Heavy metals and other                              PAH Analysis
analyses
            Acknowledgments
• CMRA and EPA
• UNH
• Facilities that provided data
                    Thank You
    Jon Powell, E.I.

I   Innovative Waste Consulting Services
    6628 NW 9th Blvd, Suite 3
    Gainesville, Florida 32605
    352-331-4828 Extension 4
    jpowell@iwcs.biz
    http://www.iwcs.biz

				
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