Minutes of the Joint TAG
Meeting focusing on CCA Research
Thursday, August 18, 2005, 10 am to 2 pm
Location: Town of Medley, Miami-Dade County
Town Hall Conference Room
in the Powerpoint presentation is preliminary and should not be cited
Gene Advincula, Florida Wood Recycling Inc., Medley, FL
Kevin Archer, Chemical Specialties Inc., Charlotte, NC
Frank Bermudez, Southern Waste Systems Inc., Dania Beach, FL
Colleen Block, University of Miami, Coral Gables, FL
Lee Casey, Miami-Dade County Solid Waste Dept., Miami, FL
Claire Cornillier, CTBA – Technical Center of Wood and Furniture, Bordeaux,
Brajesh Dubey, University of Florida, Gainesville, FL
Jonathan Fernandes, University of Miami, Coral Gables, FL
Shannon Ferrell, East Coast Recycling, Ft. Pierce, FL
Lora Fleming, University of Miami, Miami, FL
Carlos Hernandez, Miami-Dade Dept. of Environmental Resources Mgt, Miami, FL
Stewart Holm, Georgia Pacific Inc., Atlanta, GA
Naila Hosein, Westhorp and Associates, Miami Shores, FL
Jim Hickman, Langdale Forest Products, Valdosta, GA
John Horton, Osmose Inc., Griffin, GA
Gary Jacobi, University of Miami, Coral Gables, FL
Danny Kreiser, East Coast Recycling, Ft. Pierce, FL
Robert Lagasse, Mulch and Soil Council, Washington D.C.
Eduardo Lam, University of Miami, Coral Gables, FL
Damaris Lugo, Broward County Environmental Protection Dept., Plantation, FL
Glenn Malmstrom, Florida Dept. of Environmental Protection, Tallahassee, FL
Anadi Misra, University of Florida, Gainesville, FL
Cindy Mulkey, Florida Dept. of Environmental Protection, Tallahassee, FL
Freddy Nava, University of Miami, Coral Gables, FL
Amy Omae, University of Miami, Coral Gables, FL
Mark Oncavage, Sierra Club, Miami, FL
John Schert, Florida Center for Solid and Hazardous Waste Management, Gainesville,
Harvey Schneider, Florida Wood Recycling Inc, Medley, FL
Chuck Shaw, Osmose Inc., Griffin, GA
Tomoyuki Shibata, University of Miami, Coral Gables, FL
Helena Solo-Gabriele, University of Miami, Coral Gables, FL
Richard Tedder, Florida Dept. of Environmental Protection, Tallahassee, FL
Ram Tewari, Broward County Solid Waste Division, Plantation, FL
Timothy Townsend, University of Florida, Gainesville, FL
Sermin Unsal, County Environmental Protection Dept., Plantation, FL
Adrian Vargas, University of Miami, Coral Gables, FL
Tim Vinson, Florida Center for Solid and Hazardous Waste Management, Gainesville,
Melvin Wolfe, Town of Medley, Medley, FL
C.Y. Wu, University of Florida, Gainesville, FL
The meeting began at 10:05 am and ended 2:45 pm. A lunch break was held between
12:05 and 12:30 pm. All questions and answers are paraphrased from hand-written
1. Greeting (by Mel Wolfe, Town of Medley Attorney)
2. Welcome and organization of joint meeting (Helena Solo-Gabriele and CY Wu)
3. Brief History of Florida CCA Research (Helena Solo-Gabriele)
Mel Wolfe provided the official greeting on behalf of the Town of
Medley. He thanked the FDEP for funding the Innovative Recycling Grant
and acknowledged Florida Wood Recycling and the University teams for
their work. Each member of the audience introduced themselves by stating
their name and affiliation. Helena Solo-Gabriele provided a summary
of the history of the Florida CCA Research. Click here [History_Aug_05.ppt]
to link to the presentation.
Question and Answers
Stewart Holm: In the C&D wood waste study, what was the range of %CCA in
the wood mulch?
Helena Solo-Gabriele: Ranged from below detection limits to 20 or 30%.
Tim Townsend: One facility measured upwards of 30%.
Richard Tedder: In the TCLP leaching results from the new versus weathered
wood, what was the size of the wood chips used in the study?
Tim Townsend: The wood chips were sized reduced so that the size passed the
standard sieve size as specified by the TCLP protocol.
Florida Center for Solid and Hazardous Waste Sponsored Research (FCSHWM)
4. Background Information Concerning FCSHWM and FCES.
John Schert described the Florida Center for Solid and Hazardous Waste Management
by describing how the Center was formed and by describing the vision for the
Center as requested by the late Senator Kirkpatrick. He emphasized that the
Center receives funding through the Florida Department of Environmental Protection
and that Bill Hinkley is instrumental in such funding.
Leaching of Treated Wood
5. Comparison of environmental impact of CCA and three different arsenic free
preservatives under several use and disposal scenarios. Presentation provided
by Brajesh Dubey. Click here [Dubey.ppt] to
link to the presentation.
6. Results from Field-Scale Deck Study. Presentation provided by Tomoyuki Shibata.
Click here [Shiba Deck2.ppt] to link
to the presentation.
7. Impact of Iron Oxidants on Leaching From Mulch. Presentation provided by
Tomoyuki Shibata. Click here [Shiba Mulch2.ppt]
to link to the presentation.
Question and Answers
John Schert: The copper standard is dependent upon the hardness of the water
and ranges highly in Florida. How is hardness taken into account in the study?
Brajesh Dubey: The hardness of the water samples are measured directly and
the samples used are representative of the range observed in Florida.
Kevin Archer: There was a mention of the possibility of a landfill becoming
aerobic, what proportion of landfills actually become aerobic?
Brajesh Dubey: In some cases air is added to landfills (such as in aerobic
bioreactor landfills). In the very long term there is also the possibility
of landfills becoming aerobic.
Tim Townsend: The thought is that once the biogas is lost air will diffuse
back into a landfill. Work under aerobic conditions is intended to look at
the other extreme.
Ram Tewari: The focus of part of the research appears to be on copper. The
studies include replicates to evaluate leaching during in-service and a focus
on disposal under MSW and C&D conditions. Are C&D landfills lined?
Brajesh Dubey: The work at the landfills focuses on simulated waste within
lysimeters. These lysimeters are inbedded within the landfill for temperature
stabilization but the waste within these lysimeters is not in contact with
the waste from the landfills.
Tim Townsend: Within a C&D landfill it appears that the copper will not
leach. The risk to groundwater appears to be lower because copper appears to
be less mobile.
Ram Tewari: Is the sulfide from gypsum responsible for binding copper?
Tim Townsend: It is likely that the sulfide is responsible for binding copper.
It also appears that sulfide-reducing bacteria may also accelerate arsenic
John Schert: How large are the lysimeters at Polk County?
Brajesh Dubey: 2 feet in diameter and 16 feet long.
John Schert: Has anyone else ever constructed such large lysimeters?
Response: Not to our knowledge, in particular, for lysimeters buried inside
Chuck Shaw: How long have the lysimeters been installed?
Brajesh Dubey: About a year, since August of last year.
John Horton: Where is the leachate drawn from within the lysimeters?
Brajesh Dubey: Through a pipe adjacent to the lysimeter.
John Horton: Has there been thought to perhaps adding soil at the bottom?
Brajesh Dubey: Soil was not included in the current lysimeters.
Tim Townsend: That’s a good question. Most landfills have sand at the
bottom. We used gravel. In previous experiments we took leachate from Jenna’s
columns and found that the amount that went through the soil was a function
of soil type.
Danny Kreiser: From the data it appears as though there was more leaching from
the MSW than from the C&D lysimeter.
Tim Townsend: The MSW lysimeter underwent the acid phase and this phase is
anticipated only early during the life of the landfill.
Danny Kreiser: Given this acid phase it may be preferable to dispose the waste
within a C&D landfill.
Tim Townsend: It’s a balance. Over the long term, it is likely that the
overall amount of leaching is similar. The first year of enhanced leaching
from an MSW landfill would be averaged out by many subsequent years of lower
Helena Solo-Gabriele: Would you expect that the temperature within a C&D
landfill is the same as within an MSW landfill?
Tim Townsend: There will be some differences with the temperature of an MSW
landfill slightly higher than that of a C&D landfill. Overall the conditions
would be similar.
Mark Oncavage: It appears that leaching is related to pH. At what pH would
leaching increase or decrease?
Tim Townsend: Leaching is greatest at both pH extremes. At a pH of 6-9 it is
the lowest but still does leach. C&D landfills are generally more neutral
in pH. Over the life of a C&D and MSW landfill the pH of the two would
be similar. The acid forming stage of an MSW landfill is generally short.
Danny Kreiser: Most C&D landfills have non-soluble materials whereas MSW
landfills contain materials that are more biodegradable.
Tim Townsend: C&D landfills are also biologically active. The biology is
different where degredation in MSW is dominated by organic materials whereas
in a C&D landfill it is dominated by sulfate reducers.
Mark Oncavage: Will leaching vary depending upon whether or not the wood is
exposed to fresh, brackish, or salt water?
Tim Townsend: There is some data that show differences with water type.
Frank Bermudez: Has data shown that groundwater near C&D landfills contain
excessively high concentrations of arsenic?
Tim Townsend: A few sites have shown elevated levels but overall, no. When
the transport of arsenic is modeled, elevated arsenic concentrations would
not be expected because it travels very slowly.
Frank Bermudez: How long will it take?
Tim Townsend: There are a lot of assumptions incorporated in the models, nevertheless,
the models indicate that it will take decades.
Danny Kreiser: What was the make up of the soils located below the
Tomoyuki Shibata: The depth of the sand layer was 60 cm (2 ft). The rest was
Helena Solo-Gabriele: The depth of the gravel layer was about 6 to 7 inches.
Danny Krieser: What was the purpose of picking a sand and a 2 ft depth, and
what were the characteristics of the gravel?
Helena Solo-Gabriele: The 2 ft depth was chosen because in some places within
S. Florida depth to groundwater can be very shallow. The sand and gravel (roughly ¾ inches)
came from local rock mining operations. The sand likely limits binding of arsenic
to the soil. Some may also be bound to the gravel which we did not measure.
Stewart Holm: How do the leaching rates compare with that of Weis and Breslin?
Tim Townsend: The leaching rates (or % leaching) was on the same order of magnitude.
Harvey Schneider: It is likely that if an organic soil were used, the arsenic
would not be as mobile.
Tim Townsend: More will likely travel through a sandy soil. The results from
the sand are likely conservative.
Frank Bermudez: Some soils down south have high concentrations of organics.
John Horton: Transport would likely be a function of both organic and iron
Lee Casey: Would you expect that mechanical abrasion would enhance leachability?
Response: These decks were not subjected to mechanical abrasion and so in that
sense the leaching rates are not conservative.
John Schert: The Florida Center sponsored a 3-year project headed by Lena Ma,
who focused on defining soil chemistry throughout Florida. This report for
this project has received a lot of “hits” on or web site.
Danny Keiser: Where is this study posted?
John Schert: At www.fcshwm.org
Ram Tewari: This experiment considers a sandy soil which is typical of a beach
boardwalk or playground. The case of a sandy soil would be directly applicable
in those cases which are common. This data is very useful under those conditions.
Harvey Schneider: How about skin contact on the wood (e.g. people walking barefoot)?
Response: That brings an entirely different exposure scenario which is not
Frank Bermudez: Does the colorant have arsenic?
Response: The colorant is an iron-oxide.
Helena Solo-Gabriele: It would be useful to measure this. The controls in the
study (untreated wood with colorant added) account for this possibility and
the arsenic levels in the leachates from these samples were below detection
John Schert: The colorant industry has conducted a significant amount of work
showing that the colorant does not contain arsenic. What was the material below
Tomoyuki Shibata: It was a geotextile.
Helena Solo-Gabriele: It is the same material used in septic tank drainfields.
Tim Townsend: That material is typically made of polyethylene which is the
same material used to for the leachate collection containers. We would not
expect a significant amount of sorption onto this material.
Danny Kreiser: The graph shows that the concentration of the arsenic in the
leachate decreases by a factor of 10 over the course of 1 year.
Tomoyuki Shibata: Yes, the concentration decreased by 90% during the first
year but we do not expect similar decreases in subsequent years as the concentrations
were “flat” towards the end of the monitoring period.
Danny Kreiser: The 5% CCA mulch is close to the legal limit after the first
Ram Tewari: What type of wood was used in experimentation?
Tomoyuki Shibata: The wood came from a wood recycling center.
Robert Lagasse: Did the graph correspond to SPLP data?
Tomoyuki Shibata: The graph corresponded to the field simulations.
Disposal of Treated Wood
8. Research Plan and Progress Focusing on an “Evaluation of Thermal Processes
for CCA Wood Disposal in Existing Facilities.” Presentation provided
by Anadi Misra. Click here [Anadi.ppt] to link
to the presentation.
9. Guest Speaker: Initiatives in France for Disposal of Treated Wood Waste.
Presentation provided by Claire Cornillier. Click here [Claire.ppt]
to link to the presentation.
10. Review of Mulch Characterization Study. Presentation provided by Gary Jacobi.
Click here [Gary_Mulch.ppt] to link to the
Question and Answers
Cindy Mulkey: How would the regulations on the cement product affect the possibility
of disposing treated wood within cement plants?
Anadi Misra: The metals would be in a less toxic form by forming metal-metal
C.Y. Wu: Cement kilns use tires, for example, as fuel. Tires also have metals
and the use of tires has not been a problem for cement manufacture.
Anadi Misra: Co-incineration of wood with other materials would dilute the
concentrations further thereby decreasing leachate concentrations.
John Schert: Paul Cooper has conducted studies focusing on burning of wood
in cement kilns. There was also a test burn in Norway. In Maine there were
2 large-scale test burns as organized by Dana Humphries.
Ram Tewari: Waste to Energy plants in Florida received a letter about burning
CCA-treated wood and MSW. Will the FDEP be willing to consider relaxing air
emission criteria so that wood can be burned?
Richard Tedder: Relaxing the criteria is not likely and burning of CCA-treated
wood was not highly considered by MSW facilities.
C.Y. Wu: There may not be a need to relax air regulations. Arsenic emissions
may not be a problem if the right sorbent technology is utilized.
Danny Kreiser: The European limit for As was 25 ppm.
Claire Cornillier: This corresponds to the particleboard recommendation. C&D
waste wood in France was found to be in the 10 to 30 ppm limit range. Right
now C&D waste wood is used for particle board manufacture in Italy.
John Schert: How confident are you that the samples were representative?
Gary Jacobi: Representative samples are an issue. Bag samples were placed into
large bins which facilitated mixing. Samples from the bins are representative
of the bag purchased but then there’s the issue of whether or not the
bag purchased was representative of mulch as a whole.
John Schert: Would you expect that metals concentrations in the fines would
Gary Jacobi: We did observe a particle size effect. Mulch samples characterized
by small mulch sizes were the ones that generally had high concentrations of
Danny Kreiser: The research used plywood as an indicator of C&D wood. How
many samples failed that did not have engineered wood?
Harvey Schneider: The majority of wood at C&D facilities is plywood. The
plywood generally does not have CCA. Therefore the plywood should be used.
John Schert: There has been an increasing demand for treated plywood in roof
applications. It is likely that this plywood will be treated with ACQ.
Richard Tedder: There were 4 plywood samples that were not colored and these
did not contain detectable levels of arsenic. Also, it appears that the XRF
guns are good for only detecting high levels of arsenic in mulch.
Robert Lagasse: Were both SPLP and total recoverable metals measured.
Gary Jacobi: Yes, both were measured and the results from each were very similar.
Tim Townsend: The analysis for total metals is more difficult than the SPLP,
thus the SPLP would serve as a simpler screening tool for testing mulch.
Harvey Schneider: If pure vegetative wood (e.g. tree trunks and branches) were
tested there can also be elevated levels of arsenic if the trees were grown
in areas with high arsenic levels? Were samples of pure vegetative wood tested?
Tim Townsend: It is likely that some samples in the study contained only vegetative
Helena Solo-Gabriele: It was difficult to tell from the labels on the bags
if they were made of pure vegetative wood.
Identification and Sorting
11. a. Results from “Augmented Sorting of Recovered Wood Waste Using
Stain and X-Ray Technologies.” Presentation provided by Colleen Block,
Gary Jacobi and Helena Solo-Gabriele. Click here [Colleen.ppt]
and here [Medleyb.ppt] to link to the presentations.
b. Sorting Recovered Wood from the Recyclers Perspective. Presentation provided
by Harvey Schneider.
12. Progress on “Year 9” Newly Funded Project Focusing on “An
Arsenic Specific Stain for CCA-Treated Wood.” Presentation provided by
Amy Omae. Click here [Amy.ppt] to link to the presentation.
Question and Answers
Gene Advincula: Given the comparison between the AA and XRF, it appears that
the XRF is sufficient.
C.Y. Wu: XRF is designed more for surface detection of metals.
Question: What type of sample was used for the AA?
Colleen Block: The samples used for AA analysis were drilled at the XRF measurement
Stewart Holm: How deep did the drill go?
Colleen Block: The whole 1.2 cm depth was drilled.
C.Y. Wu: Was the XRF unit calibrated?
Colleen Block: The instrument was calibrated at the factory.
Frank Bermudez: Eight hours per ton for sorting is too much.
Harvey Schneider: The amount of time to sort is not realistic. The way that
they sorted involved separation of the wood into different wood types which
is not the actual way wood will be sorted.
Helena Solo-Gabriele: A more realistic sort was completed yesterday where separation
was not based upon wood type. The results from this sort should be available
Ram Tewari: Given the presentation does this imply that C&D recycling,
especially those in South Florida, should be more heavily monitored
Harvey Schneider: It is really up to the owners and operators. The owners and
operators need to use Best Management Practices in order to assure the long
term sustainability of the industry. We now have the tools. As a business we
need to move forward.
Richard Tedder: Will there be additional work for evaluating the arsenic
Amy Omae: The test that has been developed works. We are running low on time
and funding and so the existing stain, based upon the Stannous Chloride combined
reagent, will be the final method developed from the current study.
Frank Bermudez: What type of equipment is available for the very large facilities,
those that process many tons of wood per day?
Helena Solo-Gabriele: There are more automated detection systems based upon
XRF. For example, Spectro-ASOMA has manufactured XRF units for automated sorting
of different types of plastic. The same technology can be used for wood as
long as the conveyor system, to introduce the wood and removed treated pieces,
can be properly designed.
13. Pilot Epidemiologic Study Evaluating Potential As Exposures to Children
from CCA-treated Playgrounds. Presentation provided by Lora Fleming. Click
here [Fleming.ppt] to link to the presentation.
Question and Answers
Mark Oncavage: Are there other similar studies?
Lora Fleming: There’s a study by Kwon et al. that provided arsenic concentrations
on hands. This was published in Environmental Health Perspectives in 2004.
The levels in the Kwon study were similar to ours.
Mark Oncavage: How about skin exposure, is there a concern?
Lora Fleming: The primary route for children would be ingestion through hand-to-mouth
Stewart Holm: The Wester paper reports that arsenic from CCA is not dermally
Lora Fleming: The route of exposure must be defined. In the case of hand-to-mouth
behaviors the exposures can be reduced through hand washing.
Ram Tewari: Have studies been conducted on workers who handle CCA?
Lora Fleming: There are a few studies for workers and the primary concern has
been inhalation of dust. There has been 1 study in Hawaii.
Stewart Holm: Other studies (7 others) have shown the same general result.
Richard Tedder: It appears from the results that stains help reduce exposures.
Which stains are appropriate?
Helena Solo-Gabriele: The U.S. Environmental Protection Agency and the U.S.
Consumer Products Safety Commission have initiated a study that focuses on
which stains are more effective. They released a draft of their preliminary
findings a few months ago.
John Schert: Usually oil-based penetrating stains are recommended. Film coating
paints are not recommended because of chipping.
John Schert: I have also been struck by the number of playgrounds that have
been converted by local governments to other materials.
Lora Fleming: Dade County is getting rid of their CCA-treated playgrounds.
However, there are many home-owners with CCA-treated playgrounds.
Danny Kreiser: What was the maximum level of arsenic observed in the soil?
Tomoyuki Shibata: 42 mg/kg.
Kevin Archer: What do you plan to do with the data?
Lora Fleming: We are currently working on publishing it. Publishing this study
has been difficult due to the small sample size.
Stewart Holm: The study should be published since it can be used as a comparison
with the Kwon study.
Damaris Lugo: Have there been efforts to compute cancer risk given the data?
Lora Fleming: These computations can be performed but they would be based upon