at the Florida Power and Light, Distribution Environmental
2455 Port West Boulevard, West Palm Beach, Florida
Alternative Chemicals and Improved Disposal-end Management Practices for CCA-Treated Wood
Presentations from 10:00
am to 12:00 noon
Lunch Courtesy of Florida Power and Light from 12:00 noon to 1:00 pm
Tour of FPL Recycling Operations from 1:00 pm to 3:00 pm
2. History of Research Project
-Introduction, Summary of Project Results Solo-Gabriele Through Year 2 (U.M. and U.F.) and Status of Year 2 Report
-Summary of Work Conducted at U.F. Townsend
-Objectives of Year 3 Study Solo-Gabriele
-Research Completed To Date for Year 3
-Alternative Chemicals , Phase I Solo-Gabriele
-Disposal-end Management, Phase II
-Field Study for Chemical Stains Kormienko
-Pyrolysis Evaluation Kormienko
-Sourcebook for Disposal Sector Townsend/Stook
-Discussion of Year 3 Results
-Ideas for Year 4 Study
Adjourn for Lunch
Kevin Archer, Chemical Specialties Inc., Charlotte, NC
Bill Benton, Florida Power and Light, Daytona, FL
Marc Bruner, Solid Waste Authority, West Palm Beach, FL
Vandin Calitu, University of Miami, Coral Gables, FL
Ken Cogan, Hickson Corp., Conley, GA
Keith Drescher, Florida Power and Light, West Palm Beach, FL
Bill Gay, Langdale Forest Products, Valdosta, GA
Jeff Gould, Florida Dept. of Environmental Protection, Ft. Myers, FL
Bob Graham, Florida Power and Light, West Palm Beach, FL
Jim Healey, Koppers Industries Inc., Gainesville, FL
Jim Hickman, Langdale Forest Products, Valdosta, GA
Katherine Kormienko, University of Miami, Coral Gables, FL
Monika Kormienko, University of Miami, Coral Gables, FL
Danny Kreiser, East Coast Recycling, Ft. Pierce, FL
Jerry McMullan, Florida Power and Light, West Palm Beach, FL
Katie O'Reilly, Florida Power and Light, West Palm Beach, FL
Dan Rawson, Florida Power and Light, West Palm Beach, FL
Roger Sanders, Florida Power and Light, Melbourne, FL
John Schert, Univ. Florida Florida Center for Solid and Haz. Waste Mgt., Gainesville, FL
Jeffrey Smith, Florida Dept. of Environ. Protection, West Palm Beach, FL
Helena Solo-Gabriele, University of Miami, Coral Gables, FL
Jin-Kun Song, University of Florida, Gainesville, FL
Kristin Stook, University of Florida, Gainesville, FL
Don Surrency, Koppers Industries Inc., Gainesville, FL
Susan Sweeney, Florida Power and Light, West Palm Beach, FL
Ram Tewari, Broward County Solid Waste, Broward County, FL
Thabet Tolaymat, University of Florida, Gainesville, FL
Tim Townsend, University of Florida, Gainesville, FL
Helena Solo-Gabriele welcomed all the attendees to the meeting and thanked Florida Power and Light for hosting the technical advisory group (TAG) meeting. Each attendee introduced themselves by stating their name and affiliation. Keith Drescher welcomed meeting attendees to the FPL facility. He described the environmental and recycling operations at the site. John Schert described the initiatives of the Florida Center for Solid and Hazardous Waste Management. He listed the current projects that were funded.
2. History of Research Project
Helena Solo-Gabriele described the history of the project. The project was initiated several years ago due to high metals concentrations observed in the ash from wood cogeneration plants. A mass balance analysis was developed as part of the year 1 study to determine whether CCA treated wood was a likely cause. From the mass balance it was found that the quantities of CCA treated wood disposed will increase significantly in the future. Samples collected from construction and demolition (C&D) facilities found that roughly 6% of wood waste recycled at these facilities is CCA treated. Energy recovery was found to be the primary disposal pathway for the recycled wood waste. Given this situation, the focus of the year 2 study was to develop tools for better managing this waste stream. Technologies were evaluated for sorting CCA-treated wood from other wood types. These technologies included the use of chemical stains and x-ray fluorescence. Both technologies performed well in the laboratory. During year 2 the research team also evaluated leaching characteristics of CCA-treated wood ash. The leaching study included TCLP and SPLP tests as well as extractions using other chemicals. TCLP tests showed that CCA-treated wood ash will likely be classified as a hazardous waste, even when CCA-treated wood represents less than 5% of the mixture. Solvents tested were revealing from an environmental perspective in that metals were mobile with relatively weak solvents. Metals removals of up to 60% were observed with the strongest solvents. Developments since the last meeting on the ash study included a set of additional experiments conducted to better establish the total metals concentration of the ash prior to extraction. These experiments include neutron activation analysis, direct measurements of the retention levels of the untreated wood, and direct measurements of the percent arsenic volatilized. Ash samples have also been shared with other researchers. The status of the year 2 report was presented. The goal is to have the draft finalized in August 1999.
Timothy Townsend described the C&D operations in Florida. He described the sampling protocol for collecting wood waste samples during year 1. The year 1 study showed that CCA-treated wood can be found in wood waste piles at C&D facilities. The composition of the wood waste piles was 6% CCA-treated wood by weight. Analysis of the ash samples during year 2 followed standard TCLP and SPLP tests. Results from these tests indicated that ash samples containing pure CCA were found to be hazardous and some wood waste samples collected from C&D facilities also failed TCLP criteria. Some failures were observed for chromium and others were observed for arsenic. Differences between the TCLP and SPLP tests were discussed. Results indicate that wood ash containing very small quantities (less than a fraction of 1%) should not be land applied. A 5% mixture of CCA-treated wood (5% CCA at 0.25 pcf and 95% untreated) was found to be borderline for failing TCLP. This finding is significant from a sorting and economic perspective. A hazardous designation will greatly escalate the cost for ash disposal. If the objective is to not produce a hazardous ash, then sorting should be efficient enough to maintain CCA mixtures below 5%.
Question: John Schert asked what fraction of the arsenic is volatilized during a typical incineration process.
Response: Volatilization is a function of temperature. The higher the temperature the more volatilized. For the temperatures (approx. 1100 oF) observed during the incineration of the wood ash samples prepared during year 2, the research team estimated that approximately 50% of the arsenic would be volatilized at the high end.
Question: John Schert asked what fraction of the total wood stream is expected to be composed of CCA-treated wood.
Response: Untreated wood was not included in the disposal forecast; however, inquiries made to the Southern Forest Products Association, which compiles statistics on wood usage in the southeast, indicate that currently one in every four wood products sold is treated with CCA. Therefore, one would expect in the future that CCA-treated wood could represent roughly 25% of all wood disposed.
Question: Marc Bruwer asked if the CCA-treated wood currently observed in the disposal sector was from construction or from demolition.
Response: It is anticipated that the majority of the CCA-treated wood disposed today is from construction activities. The proportion will shift toward demolition waste in the future. The data collected from pilot studies will be presented shortly which documents the characteristics of construction and demolition wood waste.
Question: Marc Bruwer asked whether the stains could be used to determine the % CCA in a wood mixture.
Response: The stains can be used to determine whether CCA is present or not; however, quantification (e.g. 3 versus 5% ) cannot be done. Quantification is possible however with the x-ray fluorescence technology.
Question: Ram Tewari asked whether the methods of "ultimate" ash disposal from wood cogeneration facilities were evaluated.
Response: The ultimate disposal of the ash was not determined; however, such a study would be worthwhile.
Question: Ram Tewari asked whether the ash from air curtain incinerators has been evaluated. Response: Such a study has been conducted by Dr. Shieh of the Florida Institute of Technology. Dr. Shieh found that the ash from wood waste (e.g. pallets) contained higher metals concentrations than the ash from vegetative waste.
Comment: Keith Drescher emphasized that an air permit exemption was obtained to incinerate the wood samples in the Florida Power and Light incinerator.
Question: Danny Kreiser asked how much wood was burned.
Response: Ten batches of 100 pounds each were burned.
Comment: Cogeneration fees grew from the lowest to the highest in a two year period. As a result use of wood waste has shifted from cogeneration to mulch. The amount of CCA potentially in mulch should be compared to the amount of metals applied in residential areas in the form of fertilizers.
Question: Danny Kreiser asked whether CCA is capable of leaching from mulch.
Response: When wood is ground up it exposes portions of the weathered wood that contains higher concentrations, thereby increasing the likelihood for leaching.
Objectives for Year 3 and Status Report for Research on Alternative Chemicals
The objectives for year 3 focus on evaluating alternative chemicals (phase I) and on developing disposal management strategies (phase II). Alternative chemicals are considered to represent a potential long-term solution to the disposal problem associated with CCA-treated wood. Disposal-end management strategies are needed to handle short-term (next 25 to 50 years) disposal of CCA-treated wood. Disposal-end management strategies are separated into three tasks: field demonstration of sorting technologies, evaluation of pyrolysis technology, and developing a sourcebook for the wood disposal sector. Chemicals considered for phase I include those that contain no arsenic, have been used commercially to some extent, have been standardized by the American Wood Preservers' Association (AWPA), and are waterborne preservatives. Seven chemicals have been found that meet these criteria: AAC, ACC, ACQ, Borates, CBA, CC, and CDDC. Methods for evaluating these alternatives include contacting manufacturers, reviewing AWPA standards, and sending questionnaires to large-end users and wood treaters concerning perceived advantages and disadvantages in the use of alternative chemicals. Contacts have been made with alternative-chemical manufacturers and the AWPA standards have been reviewed. Questionnaires have been mailed. An initial evaluation was provided for the four most promising alternatives which include ACQ, CBA, CC, and CDDC. Comments were made about the corrosivity of some alternative-chemical treated wood and concerning potential mold issues. All these alternatives contain copper which may not be acceptable for submerged water use.
Comment: Marc Bruwer mentioned that the Home Builders Association should also be contacted as part of the large end-user inquiry.
Comment: Ken Cogan mentioned that hot-dipped galvanized fasteners are recommended for all treated wood.
Comment: Kevin Archer mentioned that mold is also a problem with CCA and additives are available to control mold.
Comment: John Schert provided several ideas for next year's study. These included: an evaluation of why alternative chemicals are used and who uses them, evaluating CCA leaching characteristics, increasing consumer awareness, determine the leachability of weather-proofed CCA-treated wood.
Field Study for Chemical Stains
Monika Kormienko summarized the results from the pilot studies at C&D facilties. Three chemical stains were evaluated: chrome azurol, rubeanic acid, and PAN indicator. The objectives of the field studies were to determine whether the chemical stains could be used at C&D facilities to sort CCA-treated wood from other wood types. Two C&D pilot studies have been conducted to date. For a construction pile evaluated, most of the CCA treated wood was in the form of cut-offs. Most of the treated wood in the demolition pile was dimensional lumber. Both sites contained pre-sorted wood waste piles. The amount of CCA treated wood in these piles was 9 to 10% by weight for both sites. The performance of the stains was discussed. PAN indicator was the quickest chemical to react; however it was subject more interferences than chrome azurol. Interferences were noted with paint and nails. Practical applications of the stains include sorting small quantities of treated wood from other wood types and screening fuel quality.
Questions: John Schert asked what happens to the wood once it is sorted out at C&D facilities.
Response: It is generally landfilled.
Questions: Bill Gay asked about efforts for pre-sorting CCA-treated wood before it reaches the C&D facility.
Response: Not much sorting generally occurs at a demolition site. Reference was made to another study investigating deconstruction. John Schert mentioned that the deconstruction project focuses on recovering products that have a market value.
Sourcebook for Disposal Sector
The rationale for developing the sourcebook was presented by Timothy Townsend. The purpose of the sourcebook is to assist individuals who ultimately must dispose treated wood. The sourcebook will include a list of disposal options for CCA- , creosote, and pentachlorophenol- treated wood. Disposal options listed in the book will include options for landfilling, incineration, and reuse/recycling. The method for developing the questionnaire will include sending a questionnaire to waste management facilities in Florida. Targeted facilities include wood burning facilties, C&D facilities, MSW facilities, and cement plants. The schedule for developing the questionnaire was presented.
Comment: Ken Cogan mentioned that all three CCA manufacturers have developed consumer information sheets to be distributed by retail outlets. These sheets however are not always distributed to the consumer.
Comment: Kevin Archer mentioned that the research team should inform the recycling committees of the AWPA and the AWPI (American Wood Preservers' Institute) of their work.
Comment: John Schert mentioned that the CCA manufacturers are in a difficult position having to inform consumers of the disposal issues associated with CCA while at the same time promoting the use of the chemical.
Comment: Ram Tewari recommended that regulatory groups become involved in better establishing policy for use of CCA-treated wood as mulch and for evaluating the impact of CCA-treated wood on landfill leachate characteristics. This was considered a good point and it was mentioned that several individuals from the regulatory group are on the TAG and communications are maintained with regulators that are non-TAG members.
Question: Danny Kreiser asked if there have been leachate studies conducted on wood chips.
Response: Some studies are available. Some lysimeter studies have been initiated at the U. Florida laboratory and more data should be available next year.
Ideas for Next Year
Helena Solo-Gabriele requested that the attendees provide ideas for next year. During lunch the following ideas were provided.
Ken Cogan: Consider additives for the ash (such as calcium compounds) that bind the metals to the ash so they do not leach.
Bill Gay: Consider following-up with the work by Cooper on cement board composites.
John Schert: Consider the following. What is the concentration of CCA in soils at playgrounds built using CCA-treated wood? Who is using alternative-chemical treated wood, why, and where? Is the leachability of chipped CCA-treated wood a problem? What are the leaching characteristics of CCA-treated wood in C&D and MSW landfills? Has the leachability of CCA-trreated wood changed since the 1970s? Consider consumer information and education.
Bill Gay and Jim Hickman provided the following suggestions shortly after the TAG meeting. Investigate sorting technologies on potential alternative preservatives. Investigate recycling alternatives of these products and impact (confusion) if waste stream of treated material becomes mixed with look alike material (i.e. ACQ,CCA). Continue efforts on pyrolysis as it seems to have cost effective potential. George at FPL said he can not keep a pole in the ground for fast decay in a area that has benzene contamination. Has benzene been tried as an extractive?
TOUR: A group tour, lead by Bob Graham and Dan Rawson, was held immediately after lunch. The tour included visits to FPL's cable recycling center, transformer decommissioning building, parts refurbishing building, and facilities for cardboard recycling and recycling of light fixtures. After the primary tour of the recycling centers, one portion of the group toured the pole barn whereas the other portion toured the laboratory facilities.