Minutes of the October 22, 2004 TAG Meeting
Room 287, Reitz Union, U.Florida Campus
David Dee, Landers & Parsons,
Henry Freedenberg, Florida Department of Environmental
Don Geiger, Innov-X,
Jim Hickman, Langdale Forest
Neven Kresic, Malcolm Pirnie,
Jesse Lewis, Wheelabrator Ridge
Robert, Manning, Hopping Green
& Sams, P.A.,
Cindy Mulkey, Florida Department
of Environmental Protection,
Andrew Nguyen, Wheelabrator Ridge
Jim Pennington, Florida Department of Environmental
Sandy Wright, Malcolm Pirnie,
The meeting began at 10 am and stopped for lunch at 12:20 noon. During lunch demonstrations of the Innov-X XRF unit and arsenic-specific chemical stains were made available.
1. Welcome and organization of joint meeting.
Helena Solo-Gabriele and C.Y. Wu welcomed the participants to the meeting. Each participant in attendance introduced themself by stating their name and affiliation. Helena Solo-Gabriele briefly reviewed the agenda for the meeting.
Brief History of
Jim Pennington: The 5% value corresponded to mulch?
Response: The amount of CCA-treated wood found in recycled C&D wood waste piles throughout the state was 6%, by weight.
3. Background Information Concerning FCSHWM.
John Schert described the FCSHWM and their funding history for CCA-treated wood issues. He also emphasized that the research group hosted an international conference last February which was attended by 150 people from 15 different countries.
4. Progress on “Year 7” and “Year 8” Studies Focusing on Mulch. Click here for presentations by Gary Jacobi (Gary_mulch.ppt) and by Tomoyuki Shibata (Shiba_mulch.ppt).
Tim Townsend: Are the unit milligrams per kilogram of ash or milligrams per kilogram of wood?
Response: mg per kg of wood.
Question: Does the arsenic volatilize during ashing?
Response: Yes. A study was conducted to evaluate arsenic volatilization. Mulch samples were spiked with solutions containing arsenic and the samples were then ashed. After ashing about 80% of the arsenic was recovered. So yes, some volatilizes but much of it is retained during the ashing step.
Frank Coggins: What is the nature of the red colorant?
Response: It is made of an iron oxide.
Don Geiger: Can the colorant contribute to the arsenic?
Response: The contribution from the colorant is considered to be small in relation to the contribution from CCA.
John Schert: Other studies have observed a relationship between particle size and arsenic concentration with fines containing higher concentrations of arsenic. Have you evaluated such a relationship?
Response: No, the sample was not split up to analyze for different size fractions separately. The mean size fraction was measured and this can be compared to the overall metal concentration for a particular sample. The reason we ran the size distribution analysis was due to claims from a mulch manufacturer who indicated that if a company is trying to “hide” the presence of C&D material within mulch they may grind it to a finer size. We analyzed the size distribution of the samples for this reason.
John Schert: Could the high chrome hits be due to chrome paints. Older paints tended to use chrome.
Response: Yes, paint is one possible explanation for the high levels of chromium (versus arsenic) observed in the samples.
Sandy Wright: Why was the 12 ug/L threshold value set for arsenic?
Response: The 12 ug/L value corresponded to the detection limit of the analytical method used.
David Dee: In the big picture, the data suggest that groundwater may be contaminated by mulch. The data also show that 80 to 90% of the commercial mulches are acceptable. 12 to 13% are potentially a problem. These fractions indicate that overall most mulches are of acceptable quality, which is better than I had anticipated.
Response: True. Also of interest is the finding that mulches purchased in bulk have a higher tendency of being contaminated.
David Dee: It was also observed that higher arsenic concentrations were observed in the mulches sold farther south.
Tim Townsend: Most of the C&D recyclers are located farther south. This is the likely reason for the geographic distribution that was observed. I am surprised that there was still a good fraction of mulches that were contaminated, in particular given all of the media attention.
John Schert: What was the time period when these mulches were purchased?
Response: The samples were purchased for the “rest of
Tim Townsend: Was there a correlation between pH and the samples with the high chromium concentrations in the pH. C&D wood frequently will be co-disposed with concrete which can impart a high pH to the mulch. Higher pH values tend to convert the chromium towards the hexavalent state.
Robert Manning: The leaching from the mulch is high during the initial period and then decreases.
Response: Yes, the highest concentrations were observed during the first few storm events. After that concentrations leveled off.
Tim Townsend: Were SPLP run on the mulch samples used in the observation boxes?
5. Progress on “Year 9” Newly Funded Project Focusing on “An Arsenic Specific Stain for CCA-Treated Wood”. Click here for presentation by Amy Omae. (Amy_Stain.ppt)
Henry Freedenberg: What is the timing for the color change of the CCA solution?
Response: The color change is gradual and takes a total of about 30 minutes.
6. Progress on “Year 7 – RCRA Study” Focusing on Disposal Options for CCA-treated wood. Click here for presentation by Helena Solo-Gabriele. (RCRA.ppt)
7. Comparison of Environmental Impacts of Wood Treated with CCA and Three Different Arsenic-Free Preservatives. Click here for presentation by Brajesh Dubey. (Dubey_AltChem.ppt)
8. Research Plan and Progress Focusing on an “Evaluation of Thermal Processes for CCA Wood Disposal in Existing Facilities.” Click here for presentation by C.Y. Wu. (Wu.ppt)
Robert Manning: What type of combustor was used?
Response: The combustor was placed in a furnace.
Robert Manning: Was 900 degrees Celcius the maximum temperature that could be attained?
Response: The 900 degrees Celcius was the temperature that was used in the experiments but the temperatures can be set to a higher value. Also it is noted that metals tend to recondense on particulates as the gas cools.
Response: The ash is significantly more concentrated than the original wood.
John Schert: There’s a test burn that was conducted in
Response: We have contacted the group in
John Schert: Paul Cooper of the
Response: I don’t know. There have been many studies on different types of combustion processes. In particular there have been studies that have focused on the use of sorbents during the combustion of coal.
Helena Solo-Gabriele: Was chromium leaching measured?
Response: Yes. Kaolin appears to be a good candidate to control the chromium. Some of the other sorbents were found to increase chromium leaching.
Robert Manning: Which air pollution technology is good at capturing emissions?
Response: Electrostatic precipitators are installed at most power plants and bag houses are installed at cement kilns. Efficiency of particle capture by this equipment is typically better than 90% for coal and MSW combustion.
8. Research Plan for “Augmented Sorting of Recovered Wood Waste Using Stain and X-Ray Technologies.” Click here for presentation by Helena Solo-Gabriele. (Innovative_Grant.ppt)
David Dee: The XRF instrument may be good for spot-checking the wood.
Frank Coggins: What is the cost of the instrument?
Response: On the order of $30,000.
Update on Study Funded by The Environmental and Occupational Health Sciences Institute (EOHSI) jointly sponsored by UMDNJ - Robert Wood Johnson Medical School and Rutgers the State University of New Jersey/NIEHS
9. Pilot Epidemiologic Study Evaluating Potential As Exposures to Children from CCA-treated Playgrounds. Click here for presentation by Tomoyuki Shibata.
David Dee: Did you discuss the arsenic concentrations in the urine?
Response: We have not yet released those results.
C.Y. Wu: What is the potential for inhalation?
Response: There should be no volatile arsenic from the wood under normal use conditions. There may be some exposures from sawdust. The main route of exposure is considered to be ingestion.