CC -

36

A-TREATED WOOD

on the industry In approximately 15 years, the amount of CCA-treated wood headed for disposal is expected to peak And like an unwelcome mother- in-law, over time, the effects of arsenic leaching from the wood could wind up being a nagging problem

CCA-treated wood recently has received much attention over soil and water contamination from structures made from this common building material; the possible effects on those workingwith the wood, and the poten- tial danger to children who play on treated wood structures. These issues continue to unfold

However, for the past five years, a team of researchers led by Helena Solo- Gabriele of the University of Miami, Fla , and Timothy G Townsend of the Uni- versity of Florida, Gainesville, with fund- ing from the Florida Center for Solid and Hazardous Waste Management, a state-

“The research has been good and quite strong, and there is a bona fide concern,” says Bill Hinkley, chief of the bureau of solid and hazardous waste for the Flor- ida Department of Environmental Pro- tection (FDEP), Tallahassee “The bottom line is that there’s no arguing that arse- nic leaches out of CCA-treated wood, and there’s no doubt that the burden is going to fall on the waste industry to sort out The dispute centers on what we are going to do about it ”

While all aspects of CCA-treated wood use currently are facing scrutiny in the state, Florida research primarily has focused on the effects of discarded CCA- treated wood In fact, it was a waste man- agement issue that began the interest in this subject, Townsend says [See “More than Child’s Play,” on page 371

Basic Facts Preserved or treated wood is a common

component of the solid waste stream. A 1998 U.S. Environmental Protection

W a s t e A g e

Agency (EPA) study estimated that 136 million tons of building-related construc- tion and demolition (C&D) debris were generated in 1996, with wood represent- ing the largest component According to the report, approximately 500 wood processing facilities in the United States derive wood from C&D

Because preserved wood products are treated by applying pesticide to the wood to prevent fungal or micro- bial decay, questions often arise as to how to best manage discarded treated

wood, from both from a regulatory and an environmental perspective.

Common U S . wood preservatives include creosote and pentachlorophe- nol. But the predominant preservative used today is CCA, which introduces concentrations of copper, chromium and arsenic to the wood.

As part of the CCA wood treatment process, wood first is dried in a kiln. The dried wood then is placed in a vessel where a vacuum is applied to the wood’s pore space. CCA solution is introduced

into the vessel, which then is placed under pressure This causes the CCA solution to enter the wood’s pore space A vacuum extracts the excess solution And after the wood is removed from the vessel, it dries over a drip pad

CCA solutions vary among wood treat- ers, but there are three typical formula- tions, as defined by the American Wood Preservers Institute (AWPI), Fairfax, Va , based on the solution composition by percent mass of the metal compounds used [See “CCA-Treated Wood Types

The concern about chromated copper arsenate (CCA)- treated wood is much larger than parents’ worries about poisonous playgrounds. In fact, the research and recent publicity surrounding the issue actually stemmed from - and is focused on - the waste industry.

“When we the started the research here in 1996, it was all based on waste,” says Timothy Townsend, one of the lead researchers studying the effects of CCA-treated wood and associate professor with the Gainesville-based University of Florida department of environmental engi- neering and science. “It’s a big deal for C&D (construc- tion and demolition) recyclers. And it’s a potentially big deal to municipal disposers. There weren’t any issues in terms of Contamination of soils, kids and playgrounds.”

Approximately five years ago, the Florida Department of Environmental Protection (FDEP), Tallahassee, decided to test the ash coming from a co-generation plant in south Florida, according to Bill Hinkley, chief of the bureau of solid and hazardous waste for the FDEP. The industrial facility, which was built next to a sugar mill, had two large wood-fire boilers designed to burn wood to produce electricity from the high-pressure steam, and burn off the water using the low-pressure steam.

The company was taking the waste from the sugar industry, burning the bagasse, which is the fiber that remains after extracting the sugar from the cane, then applying the ash onto the muck fields because it is high in phosphorous, potassium and other nutrients.

To keep the boilers operating at capacity, the company decided to burn wood waste during its slower periods, and Florida’s nearby Dade, Broward and Palm Beach counties were encouraged to take advantage of this oppor- tunity to recover their wood waste.

The facility wanted to continue spreading its ash on the sugar cane fields, but the FDEP was concerned there might be lead-based paint in the recycled wood. To ensure lead levels weren’t too high, the FDEP asked the facility to test the ash, Hinkley says. “When we got the data back, we found 400 to 500 parts per million of arse- nic and high levels of chromium in the ash.”

Current federal primary drinking water standards limit arsenic to 50 parts per billion. And U.S. Environ- mental Protection Agency (EPA) toxicity characteristic

leaching procedure (TCLP) limits are 5 milligrams per liter (mg/l).

“This drove us to ask the Florida Center for Solid and Hazardous Waste [Gainesville, Fla.] for help in research- ing the issue,’’ Hinkley says. “Eventually the arsenic was traced to CCA-treated wood.” And Townsend and Helena Solo-Gabriele of the University of Miami, teamed up to tackle the CCA-treated wood research from a waste-to- energy, mulch and disposal perspective. Their research is funded by the center.

“Our research grew through a series of studies to determine how much CCA was out there, the potential impacts and how much will be out there in the future,” Townsend says.

Now, five years after the initial research began, con- cern about CCA-treated wood in playgrounds has made its way into mainstream media.

“When we asked the center to take on the research, we asked them to examine four areas,” Hinkley says, “ash, mulch, landfilling and soil contamination under decks. We asked the center to test for soil contamination under decks because the FDEP operates 150 parks, and most of them have boardwalks and decks [made from CCA- treated wood] .”

Data from the deck studies showed average arsenic concentrations in below-deck soils to be 28 milligrams per kilogram of soil (mg/kg) - far above federal and state arsenic restrictions.

EPA soil screening level (SSL) limits for arsenic are 0.4 mg/kg. Florida’s soil clean-up target levels are 0.8 mg/kg for residential areas and 3.7 mg/kg for industrial areas, among the most stringent standards in the country.

‘An energetic reporter at the St. Petersburg Times noticed that playground equipment also is made from CCA-treated wood,” Hinkley says, “and the newspaper hired a consul- tant to sample soil under playground structures.”

“The arsenic levels in playgrounds were higher than Florida’s clean-up target levels, which prompted a huge wave of concern,” Hinkley adds.

But because playgrounds don’t fall under the FDEP’s jurisdiction, the Florida Department of Health and the state legislature now are attempting to address the issue.

- Patricia-Anne Tom

A U ~ U J I 2 0 0 1

+ w w w . w a s t e a g e . c o ni 37

and Requirements” on right] Of types A, B and C, C is most commonly used The concentration of CCA remaining in the wood after treatment is rated in pounds of CCA per cubic foot of wood, defined Composition TypeA TypeB TypeC

in Various CCA-treated Wood Prod- ucts” on page 401 easily be painted CCA also produces

At low retention values, CCA-treated no smell or vapor wood maintains a natural look and can The AWPI estimates that CCA in-

If anything, the research being conducted in Florida by Helena Solo-Gabriele of the University of Miami and Timothy Townsend of the University of Florida has brought the potential dangers of chromated copper arsenate (CCA)-treated wood to the attention of consumers, particularly parents who worry that their children may be playing in potentially hazardous environments. The research also has emphasized the need for better education about the material, particu-

Earlier this year, the EPA learned that its existing consumer awareness pro- gram, which was established in 1986, was not adequately informing the public, according to David Deegan, EPA spokesman. Previously, the agency’s consumer awareness program consisted of wood pressure-treaters providing consumer information sheets (CIS) to all lumber yards and retailers. The sheets detail instructions for handling treated wood products, such as using protective gloves, coveralls and face masks when sawing treated wood products.

But when the EPA realized the public was not always receiving these sheets, the agency, in May, asked the wood preservative industry and the public to pro- pose ways to ensure that information would adequately reach consumers.

Already, the U.S. Environmental Protection Agency, Washington, D.C., has held several public meetings to discuss public awareness. And, the EPA is working with the American Wood Preservers Institute (AWPI), Fairfax, Va., to step-up its voluntary education efforts.

“We’ve always tried to get the message out to consumers about the correct ways to dispose of CCA-treated wood and other kinds of treated wood,” says Scott Ramminger, AWPI president. “And we’ll continue to do that.”

As part of these efforts, starting this summer, the EPA says all CCA-treated lumber sold in the United States will be accompanied by improved safety han- dling information. By fall, stores that sell the lumber will label all pieces of CCA- treated lumber, as well as will receive stickers and signs for displays.

“Now consumers will understand that this treated wood contains arsenic,” says Stephen Johnson, EPA assistant administrator for the Office of Prevention, Pesticides and Toxic Substances. “I am pleased that the public discussions about CCA-treated wood resulted in a commitment by the industry to include end-tag labeling, in-store bin stickers and signs, and a new hotline and website.”

Meantime, the Consumer Product Safety Commission, Washington, D.C., has agreed to ask for public comments on petitions that could lead to an outright ban of CCA. And the EPA is planning to hold a public meeting of the Scientific Advisory Panel on Oct. 22, to review hazard assessment and methodologies for calculating children’s potential exposure in playgrounds where equipment is made from CCA-treated wood.

The EPA also will continue to monitor the success of its voluntary consumer information program. Find out more about the meeting by visiting www.epa.gov/ scipoly/sap.

- Patricia-Anne Tom

larly at the point-of-sale.

+ 38

creases the life ofwood productsexposed to the environment approximately seven to 12 times to 20 to 50 years, pre- serving millions of trees annually. But for many wood product applications, appearance more than performance dic- tates the material’s actual life-span.

Discarded CCA Wood Solid waste managers should note

that CCA treated wood was not widely used until the early 1970s, at which time it represented less than 15 per- cent of the treated wood market. Today CCA-treated wood represents nearly 80 percent of the market, with more than 450 million cubic feet currently being sold in the United States, according to Florida research. Approximately 6.5 bil- lion board feet are treated each year, says Scott Ramminger, AWPI president.

With the product’s recent increase in use and long service life, most of the material is presumed to still be in service [See “Projection of CCA- Treated Wood Entering Florida’s Waste Stream” on page 421. Solo-Gabriele and Townsend estimate that, assuming the current use stays constant, the amount of CCA-treated wood entering the waste stream will not peak until 2015.

“I wouldn’t be able to speculate when the amount of wood being disposed of will peak. It’s possible that it already has peaked, frankly,” Ramminger says, “but we’re interested in what the [Flor- ida] researchers come up with and are cooperating with them.”

Regardless of when the wood reaches its maximum disposal point, the issue, at least in Florida, is causing concern. Particularly, CCA’s status under U.S. federal hazardous waste regulations, current disposal practices, and future management and product options are being questioned.

Hazwaste Characterization Current U.S. hazardous waste regu-

lations require certain solid wastes to be managed more stringently because

of potential human health and envi- ronmental risks. These hazwastes must comply with more controlled regula- tions regarding storage, transport, treat- ment and disposal. Both elevated levels of arsenic and chromium can result in a solid waste being classified as a toxic- ity characteristic hazardous waste.

Toxicity characteristic leaching pro- cedure (TCLP) results of newly CCA- treated wood at the lowest retention levels show that arsenic leaches at con- centrations greater than the toxicity characteristic limit (5 milligrams per liter (mgA)), more than half the time, Florida research says. However, data on older, weathered wood appears to be less available. Research currently is being conducted on weathered wood, but data is not yet available, Townsend says.

However. discarded CCA-treated wood, among other materials, is exempt from the regulations. Part 261.4 of the Code of Federal regulations exempts:

“Solid waste which consists of dis- carded arsenical-treated wood or wood products which fails the test for the Toxicity Characteristic for Hazardous Waste Codes DO04 through DO17 and which is not a hazardous waste for any

Attributes Standard Retention (PC

other reason if the waste is generated by persons who utilize the arsenical- treated wood and wood product for these materials’ intended end use.”

Current Disposal Practices As a result, most states handle CCA-

treated wood similarly to other dis- carded wood products. However, one state, Minnesota, has not adopted this exemption in its state hazardous waste program [See “Minnesota at the Margin” on page 421.

CCA-treated wood in Florida pri- marily is managed at unlined C&D waste landfills or at C&D recycling

facilities, with smaller amounts man aged as municipal solid waste (MSW in lined landfills or at waste-to-energ; (WTE) facilities.

Herein lies the potential problem. “We try to make two statement:

about CCA-treated wood that relatc to disposal,” AWPI’s Ramminger says “One, you should not burn the wood and two, [the wood] should not bc recycled into mulch.”

But because of the hazwaste exemp tion, CCA-treated wood in Florida, an( possibly in other states, is going intc unlined C&D landfills; being burnec at WTE facilities, which increases thi

CONSTRUCT~~~~ A C r ” d S a m t u M n a ) a M I h

125CasslaWay * Herderron kV 89014 U S A 7943 Pecbe u r e - Balm Rouge LA 7CBC9 Tel 12251 751 7027 Far (2251 751 2789 (7021 5b6-8600 * F a 702) 5664739

1 -8OO-Z37=1777 www.scwrot.com

Circle No. 90 on Reader Service Card W a s t e A g e

ash’s metal concentration; and is inad- vertently being recycled into mulch.

“Are we properly disposing of this wood?” questioris FDEP’s Hinkley. “For the most part. according to the exemp- tion, we are. And the CCA fraction right now isn’t that much. But CCA-treated wood reaching disposal is projected to rise to 35 percent of the wood waste stream, and then all of a sudden this venerable wood is going into disposal - and fast. In 20 years, we’ll have cre- ated a concentrated pile of CCA-treated wood that leaches arsenic.”

“The issue becomes a matter of how much [arsenic] is in the CCA-treated wood,” says Ed Repa, environmental programs director for the National Solid Wastes Management Association of the Environmental Industry Associations, Washington, D.C. “If you pressure-treat wood, how much [of the pesticide] really penetrates the wood? How much will leach out of the wood at the landfill after it has been sitting above ground for years? I’m not sure there has been enough testing to determine this.”

This is true. No discernible pattern of CCA contaminating groundwater or soil, or increased leachate toxicity in a landfill

has been established. “But the question becomes, do we wait until it becomes a problem that we’re forced to clean up, we’re forced into some kind of compli- ance, or something else?” Hinkley asks.

From a waste manager’s point of view, in all three areas - landfills, recycling and WTE - there are some

Minnesota has been a maverick in that it did not adopt the federal hazard- ous waste exemption for chromated copper arsenate (CCA)-treated wood Treated wood is classified as an industrial solid waste and must go into municipal solid waste (MSW) landfills, says Duane Duncanson, pollution control speciallst with the Minnesota Pollution

“For the most part, I believe landfills are fol g this rule, and they’re doing their best to separate the wa uncanson says. “But we do have a lot of incineration in the state as we1 f the average consumer puts treated wood from a house project into the trash, it could wind up in an MSW land- fill or get burnt at a waste-to-energy (WTE) facility.”

Additionally, while state hazardous waste rules say all industrial waste, including treated wood, must be evaluated prior to disposal, Duncanson says this is not happening 100 percent of the time. “If every generator evaluated treated wood before disposal, this could add millions of dollars to disposal costs. Consequently, the state of has not been enforcing what the rules say about treated wood.”

For the past several years, D the state has been collecting information and analyzing studies - particularly the Florida research - with the hopes of making a ion about whether the evaluation is necessary or not - “We’re trying to address sue where we’ll either change our rules so generators can legally not evaluate their loads,” Duncanson says, “or we’ll leave the evaluation rule in place and enforce it.”

Minnesota also is watching Florida to determine the effects of burying the wood in MSW landfills or incinerating it, and to identify any beneficial reuse projects, Duncanson says.

- Patricia-Anne Tom

trol Agency, St. Paul

+ 42

very real concerns and decisions that should be made.

Landfills Disposal is the primary issue Florida

is wrestling with, Hinkley says. Whether you bury the wood in a C&D, MSW or hazardous waste landfill, arsenic-leach- ing potential should be considered.

Because of the federal hazwaste exemption, much of the CCA-treated wood is being disposed of in C&D waste landfills, which in Florida do not require liner systems. This raises con- cerns about arsenic from the wood pos- sibly leaching into the groundwater.

In rainwater leaching tests - using the U.S. EPA’s synthetic precipitation leaching procedure (SPLP) - CCA- treated wood leaches arsenic many times above the U.S. primary drinking water standard of 50 parts per billion (ppb). New CCA-treated wood exposed to rainwater leaches approximately the same amount of arsenic as that leached using the TCLP.

Additionally, C&D waste landfills simulated in the laboratory and field that contain CCA-treated wood have been found to leach arsenic. Arsenic concentrations in some leachates were greater than the arsenic drinking water standard, which serves as Florida’s Class I groundwater standard.

While some degree of dilution is per- mitted in the mixing zone underneath the landfill, the eventual lowering of the arsenic drinking water standard, cur- rently a topic of national debate [See “Up in Arms over Arsenic” on page 451,

W a s t e A g e

d

increases the chance that C&D waste landfills disposing of CCA-treated wood will have groundwater exceedances.

There is no concrete data on what impact CCA-treated wood in C&D land- fills will have on groundwater. Current Florida research is focusing on large field simulations of new treated wood and old, weathered treated wood mixed with MSW and C&D debris to determine whether old, weathered wood poses a problem if it goes into an MSW landfill. However, the data won’t be available for

a few years, Townsend says. Groundwa- ter monitoring only recently has been required in Florida, so the state needs more time to closely examine ground- water quality data. ‘1 good bit of newly treated scrap

wood fails TCLP for arsenic, but I haven’t seen any data on weathered wood and whether it fails TCLP,” says Greg Helms, environmental protection specialist with the U.S. EPA Office of Solid Waste, Crystal City, Va. “So we don’t know what the residual levels of

CCA-treated wood that is disposed of in the MSW waste stream can cause problems at WTE facilities, landfills and CB. D recycling facilities.

ptional at an Additional Cost

ED SYSTEM Producing Very High-Quality Mulch Products. Just Add Wood Fiber, Colorant, Water and 480 Volt Power

(or Optional Diesel Engine)

Learn The Market In Your First Year.

Sell So Much You’ll Need A Bigger Machine The Next Year!

6409 Granger Road * Independence, Ohio 44131

.I -888-556-3304 w w w . A m e r i m u l c h . c o m

m u l c h g u y 9 A m e r i m u l c h . c o m

Circle No. 22 on Reader Service Card 44

arsenic are in the wood that’s coming out of service. And we don’t know how much is going into landfills.”

Nevertheless, “in Florida, most of the peninsula is sand, and there’s very little clay in the soil, so arsenic has the poten- tial to go right into the groundwater,” Hinkley says. “We don’t have evidence of this, but there clearly is cause to protect groundwater. We have high rainfall, high groundwater tables and shallow wells. Add to this Florida’s problem that all of its landfills are high-rise, with some C&D landfills 60 to 70 feet off-grade, and we believe there is a potential threat.”

But make no mistake, the problem won’t be solved by getting rid of the hazwaste exemption and sending CCA wood to a MSW or hazwaste facility. And the solution isn’t as simple as requir- ing C&D landfills to install liners.

“The liner is just the beginning,” Hin- kley says. “If you require a liner on the bottom of the landfill, you have to put a liner on the top, too, to prevent the bowl effect. And if you put in a liner, you’ll create leachate and gas. So then you’ll have to put in a [leachate and gas] collection system, and you’ll have to pipe the leachate to a wastewater treat-

LOW COST 0 HIGH QUALIT)

a division of Roeda 5igns Inc. 8 00.8 2 9.302 1 / email: fax: roeda@screentech.ca 708.333.0209

16931 S . S t a t e St. South Hol land , I L 6047

Circle No. 23 on Reader Service Card W a s t e A g e

A

increase the metal concentration in those facilities’ leachate.

‘A landfill operating under Subtitle D with normal leachate treatment sys- tems will detect any release long before it becomes a serious environmental problem,” says John Skinner, executive director and CEO of the Solid Waste Association of North America (SWANA), Silver Spring, Md. “But you may have additional requirements to treat the leachate and hazardous leachate if arse- nic does leach once it’s in a landfill.”

If a wastewater treatment facility land-applies its sludge but can’t dilute the leachate enough to meet the allow- able levels of arsenic, it might not accept a facility’s leachate, Hinkley says. Then, the landfill is going to hare to pay to truck the leachate elsewhere, or install a pretreatment system.

Recycling Facilities Recycling presents its own set of

challenges. Florida is home to a large number of C&D waste recycling facili- ties that accept mixed loads of C&D

plant And suddenly you’ve gone born a bowel pit where construction p y ~ ~ ‘Ire dumping in CGrD and turned

a full waste management site ” A few years ago, Florida required

c&D sites to install groundwater mon- g1[onng systems When this happened, ‘,,early half of the state’s C&D disposal gtes closed, Hinkley says The FDEP fears that if it changes its C&D regula- [Ions and requires liners, another half of the sites could close

“The people who operate C&D sites often did not start off in the waste management business, many were in the construction business,” Hinkley explains “If we put in a new set of reg- ulations, many may decide to get out of the waste business, and I fear we’ll end up with a huge upsurge in illegal dump- ing, especially in rural areas where the one C&D site in the area could close ”

If CCA-treated wood is banned from C&D facilities,.it most likely will go to municipal solid waste Subtitle D landfills or hazardous waste Subtitle E facilities But this could potentially

It’s almost as if arsenic is screaming for attention. The metal certainly has caused concern as it leaches from CCA-treated wood. And in March 2001, President George W. Bush’s administration suffered scrutiny when EPA Administrator Christie Whitman announced the EPA would withdraw Clin- on administration-approved rules t for arsenic in drinking

til more research could be d wer standard, which was p EPA in June 2000 and

ner in the last days of cceptable level of arse- vel, or MCL) from 50

June 22, 2000 (65 FR and the final MCL of 10 ppb was published on Jan. 22, 2001 (66

6). Discussion arose when Whitman delayed the effective date of the MCL until Feb 22,2002 (see 66 FR 28342. 001) to seek additional

input on science and cost issues. ile scientists agree that the previous of 50 parts per billion

e lowered, there is no consensus on a particular safe level,” Whit- man said at the time. “I want to be sure that the conclusions about arsenic in the rule are supported by the best possible science. [Some cities and states] have raised serious questions about whether the costs of the rule were fully understood when the rule was signed,” she said.

Envlronmental groups blasted the administration for turning a deaf ear to a potential health concern. But the EPA insists that there is no safe magic number - no one really knows how low arsenic levels should be to be considered safe.

Arsenic is a toxic substance found naturally in the earth, but it also is produced during industrial processes such as semiconductor manufac- turing and petroleum refining. However, a 1999 National Academy of Sciences, Washington, D.C., study linked arsenic in drinking water to bladder, lung and skin cancer.

- Patricia-Anne Tom

by former EPA Administrator President Bill Clinton’s final term,

ic in drinking water (the maxi arts per billion (ppb) to 10 parts per billion The EPA proposed MCL of 5 ppb for ars

4

CamWall Flexible Sidewall Belt

SEND FOR A FREE DEMONSTRATION VIDEO

FULLY MOLDED ONE- PIECE CONSTRUCTION DESIGN FLEXIBILITY HIGH INCLINE COMPLETE CONVEYOR

REPLACEMENT BELTING 25 YEARS EXPERIENCE

SYSTEMS

GUARANTEED AGAINST DELAMINATION OF THE SIDEWALL OR CLEAT FROM THE BASE BELT

2420 W 1100 S , Salt Lake City. Utah 84104 Phone (801) 972.5511 i Fax (801) 972-5522

ON THE LEADING EDGE OF HIGH INCLINE CONVEYOR TECHNOLOGY

Circle No. 24 on Reader Service Card 4,5 A u g u s t 2 0 0 1 W W W . H a s t e a p e . r o m

debris, then separate the components for reuse. Wood, the largest compo- ncnt by volume. is recovered for bio- mass fuel and landscape mulch.

Red mulch is very popular in Florida, Hinkley sq-s. To create the mulch, pro- ducers chop a 1-inch chip from a mised wood stream, which includes C&D wood waste, untreated lumber, oriented strand board (0%) and particle board, then dye it for decorative or commercial land-

scaping use “The red mulch is taking the place of cypress mulch, which is great as a recycling issue because recov- ered wood is serving as a replacement for indigenous trees ’ However, CCA-treated wood sometimes is found in this mix

When chipped into mulch, the arsenic leaching potential of CCA-treated wood increases dramatically because the mate- rial is spread around and the surface area-to-mass ratio increases, the research

states. This widens the possibility of soil or groundwater contamination.

“I hasten to add that making mulch from treated or painted wood is not legal,” Hinkley says. “It should not be occurring under the law.” But when wood goes to a recycler, in some cases, identifying the wood is difficult.

“Facilities do try to pull out [CCA- treated wood]. And in some cases, CCA- treated wood may be distinguished

All eyes are on Florida, as the state leads the nation in researching how to manage chromated copper arse- nate (CCA)-treated wood waste. Because the wood is just beginning to reach disposal now, and won’t peak for another 15 to 20 years, there is no waste management manual to tell the industry what to do.

“Most of the other states that I’ve spoken with have been somewhat surprised, and sometimes not really aware of this as a waste management issue,’’ says Timothy Townsend, a lead researcher on the project and associate professor with the University of Florida, Gainesville.

“There’s no arguing that arsenic leaches out,” says Bill Hinkley, chief of the bureau of solid and hazardous waste for the Florida Department of Environmental Protection (FDEP), Tallahassee. “But is there enough leaching out that we should do something about it?” Some people ques- tion whether CCA-treated wood poses a serious waste management problem at all, he says.

“You have to look at how much CCA really penetrates the wood. How much is left as a residue when you grind it up or after it’s been sitting above ground in use for decks and things for years?” says Ed Repa, environmental programs director the National Solid Wastes Management Association of the Environmental Industry Associations, Washington, D.C. “If you think about it, I’m not sure.”

Nevertheless, several organizations including the U.S. Environmental Protection Agency (EPA) Office of Solid Waste, Crystal City, Va., continue to evaluate the research coming from Florida.

According to Greg Helms, EPA environmental protec- tion specialist, there isn’t “enough data yet to make any recommendations as an agency.” Consequently, the EPA isn’t requiring states do anything different at this time and isn’t changing the hazwaste exclusion.

‘‘If the data shows that there are risks, then we’ll look at this from a disposal perspective and evaluate the exclu- sion,” Helms says.

The EIA and Solid Waste Association of North Amer- ica (SWANA), Silver Spring, Md., also are following the research. “I don’t think you’ll have extensive areas of ground contamination from Subtitle D facilities, but we’re watching the issue and trying to understand the implica- tions of the research for our members,” says John Skinner, SWANA’s executive director and CEO.

Even without substantial data, the potential for prob- lems in the waste industry are real.

cling facilities can’t be land-applied because of the arse- nic concentration in the mulch; if [the CCA-treated wood] shouldn’t be burned because of the arsenic in the ash; and if you can’t recycle wood, which is the biggest volume of C&D debris, it’s going to be a big deal for C&D recy- clers,” Townsend says. “And this issue is a potentially big deal to C&D and municipal waste disposers if it goes into an unlined landfill or into the MSW waste stream and increases the metal concentration in the leachate.”

Indeed, CCA-treated wood can become a major prob- lem if the waste is accepted now, and then it later is deter- mined hazardous.

“If construction and demolition (C&D) landfill opera- tors end up having a contaminated site at levels beyond what the states allow, they’ll have to clean it up,” says the EPA’s Helms.

Banning the wood from certain facilities creates its own disposal problems - the materials must go somewhere.

Already, composters and C&D recyclers don’t want to handle CCA-treated wood. “C&D recyclers typically are vigilant about staying away from the material and don’t want it in their plants,’’ says Bill Turley, executive director of the Construction Materials Recycling Association, Lisle, 111.

“It‘s certainly not a material we want in a composting situ- ation where the material is going for lawn and garden use,” says Sharon Barnes, president of Barnes Nursery and former president of the U.S. Composting Council, Harrisburg, Pa.

So what to do with the wood? Florida currently is continuing its disposal practices as

is, but is seeking feedback from the industry, as well as continuing to research the issue. “We need the industry’s help and advice,” Hinkley says. “I’m obviously interested in whether other people think this is a problem. But I’m also soliciting information on what people think is the best way to approach this issue.’’

Among Hinkley’s questions are how to separate the wood, how to dispose of it, where to dispose of it - in a lined or unlined landfill, and how to process the materia1 if it is sent to a lined landfill or waste-to-energy (WTE) facility.

“We’re discarding about 5 million cubic feet per year, but this is expected to grow to 35 million cubic feet,” Hin- kley adds. “That’s a lot coming down the pipe, so we need to get organized. We’re not in a crisis; it’s another waste management problem. But it’s our job to do what we do - handle waste management problems.”

- Patricia-Anne Tom + “If the wood mulch being produced from C&D recy-

4 6 W a s t e A g e

from the rest of the wood waste,’’ Hin- kley says. “But when CCA-treated wood oxidizes and turns gray, it can be diffi- cult to separate from untreated wood.”

Samples collected from Florida C&D waste recycling facilities in 1997 found an average 6 percent CCA wood content in chipped wood piles. More recent field sorts of wood piles have found treated wood concentrations ranging from 9 per- cent to 30 percent.

Thus, CCA-treated wood presents recycling difficulties. Research indicates that the presence of 5 to 6 percent CCA wood in wood fuel can cause the ash to be a hazardous waste. An even smaller amount of CCA wood causes arsenic to leach from wood mulch at levels higher than allowable in landfills. And if the fraction of CCA is greater than 1 per- cent by weight in mulch, it will leach arsenic in concentrations that exceed the 50 parts per billion allowable under the safe water drinking act, Townsend says.

Additionally, The Connecticut Agricul- tural Experiment Station, New Haven, has researched CCA uptake by edible plants and found that romaine lettuce and the plant family that includes vegeta- bles such as mustard and collard greens

The Florida Center for Solid and Hazardous Waste, hosted by the Univer- sity of Florida College of Engineering in Gainesville, receives funding from the state legislature to “coordinate and engage in research, training and ser- vice activities relating to solid and hazardous waste management issues,’’ according to John Schert, executive director “We receive research ideas from all over the country, publish requests for proposals, and provide grants to study different waste management problems ”

Often, the center consults with the Florida Department of Environmental Protection (FDEP), Tallahassee, on research topics And when the issue of CCA arose, the FDEP asked the center to put the issue on its agenda

“Initially, the center funded our research as a one-year project,” says Timo- thy Townsend, a key project researcher and associate professor with the Uni- versity of Florida, Gainesville “Now we’re starting our sixth year of research, which certainly says something about the state’s commitment to figure out the best way to manage the material ” + - Patricia-Anne Tom

accumulate arsenic in their leafy parts “The concern is that some people

are using these decorative mulches in gardens,” which could potentially affect human health, Hinkley says

WTE Some people suggest burning the

wood at waste-to-energy facilities as a CCA-treated wood disposal option. “This may be our best solution,” Hinkley says,

considering that Florida houses 13 WTE facilities - more than any other state “But there are some questions that have to be evaluated here, too ”

During combustion, the metals in CCA-treated wood are not destroyed, but are emitted in the flue gas or con- centrated in the ash Arsenic is known to be volatile at higher temperatures, so WTE facilities’ air pollution control equipment would need to be adequately

Good Things Now Come in

IO-yard Packages Sometimes smaller is better. That’s

the idea behind the new 10-yard AutoCat from Wayne. Now you can have automated performance plus speed and maneuverability in a unit that can go anywhere.

Though smaller in size, the AutoCat is big on performance. Its curved shell design uses ultra-high strength AR400 floor and hopper sides. With a 4-foot reach, this arm can easily handle GO-, 90- and 300-gallon carts.

Simultaneous load-and-pack operation allows for non-stop collection. Adjustable wear components ensure proper arm alignment and reduce maintenance downtime.

The AutoCat is great for downtown areas, smaller routes, gated communities - wherever there is limited access. And no matter where you are. you’ll always have Wayne’s nationwide dealer network to support you.

Automated and Manual Sideloaders Since 1961

Curbtender”- FE Curbtender” - TTD Autocat-

-Tomcat’ *The Pup”

The AutaCal 1s a reglstered trademah 01 Wayne Engbneenng COrporallOn

WEC1)16 Phone: (319) 266-1721 Fax: (319) 266-8207 www.WayneUSA.com

Circle No. 25 on Render Service Curd 48 W a s t e A p e

k

designed to remove it. “All you need is 6 percent CCA

wood in the mixture and you could fail TCLP,” Hinkley says. “People want to be able to land-apply their WTE ash, but CCA could make this unfeasible. The ash could have thousands of parts per million of arsenic.”

Already, Florida researchers have conducted a simulation to determine the effects of combusting CCA-treated wood in Florida’s WTE facilities [See “Simulation of WTE Ash Mass and Arsenic Concentration from 1995 to 2016,” on right].

Assuming all discarded CCA-treated wood was disposed in Florida’s WTE facilities starting in 2000, the simula- tion shows that the total mass of ash does not increase significantly, but the concentration of arsenic does. In 2000, the concentration increases five times from 35 milligrams of arsenic per kilo- gram of ash (mg/kg) to 177 mg/kg. The

.arsenic concentration in the ash then increases yearly. This pattern follows the same trend as the amount of CCA- treated wood being discarded. By 2016, the arsenic concentration in the WTE ash in the simulation reaches 940 mg/kg, an increase of 25 times.

Possible Future Practices “We’re in a conundrum,” Hinkley says.

There are options to choose from - WTE, disposal, recycling or waste mini- mization - but each has its limitations.

Burning the wood concentrates the metals. Disposing of the wood in land- fills where it could leach arsenic poten- tially contaminates groundwater or increases leachate management costs.

Reuse is the most obvious recycling option. For example, a utility that uses CCA wood telephone poles could give the material to a farmer to build a barn or fence. However, utilities are beginning to become aware of the potential liability of giving these materials away, so fewer businesses want to do so, Hinkley says.

Additionally, there are limits to reuse because people frequently get rid of CCA-treated wood because it doesn’t look good anymore. If the wood is not aesthetically pleasing, other people may not want to reuse it, Hinkley adds.

As another recycling option, the wood could be chipped then pressed into engi- neered wood products, such as OSB. But according to Townsend and Solo-Gabri- ele, no one currently is producing treated engineered wood products. The AWPI is

50

sponsoring research at Louisiana State, Baton Rouge, to test the feasibility of recy- cling CCA wood into strand board. But businesses that create untreated engi- neered products have expressed reluc- tance to mix in CCA-treated wood because it has other properties than their typical wood mixture and presents a lia- bility, Townsend says.

CCA-treated wood could be chipped then mixed with other aggre- gates to create a lightweight wood cement composite, but no one is prac- ticing this either.

Or, the treated wood could be ground up then put through a pyrolysis pro- cess. Using this method, pyrolysis heats the organic compound of the wood and volatilizes it so only metals and carbon remain. The metals then are separated from the carbon and recovered or sent to a hazwaste landfill. Currently, two facili- ties are using this process: one in Fin- land that operates as a copper smelter, the other in France, which uses what its founders call their Chartherm process.

With each recycling option, two major points also must considered: How do you separate and collect the CCA-treated wood from the rest of the CQD waste stream? And once sepa- rated, what do you do with it?

Separation Florida research argues that CCA-

treated wood could be difficult to sep- arate out at the disposal site. New CCA-treated wood takes on a greenish tint that increases in intensity the

greater the retention level, making th wood easy to distinguish from ne untreated wood But when exposed sun and rain, the treated wood surfa often turns a similar color as weat ered, untreated wood This is especlal true for species such as Southern Yell0 Pine Once treated and untreated w commingle, they can be very diffi to distinguish from one another, Solo-Gabriele and Townsend

to distinguish by color,” Hinkley s “but there’s another way to appr this” C&D recyclers could pull CCA-treated wood based on its use

“If you look at the sales of Yellow Pin roughly half is used for decks, fence four-by-fours and very obvious coilst tion,” Hinkley explains “When I g C&D sites and look at wood piles, I spot sections of a fence or deck and gua antee it’s CCA So you could set system in a mulching situation to the wood out, and I think it’s feasib eliminate CCA in that product ”

Chris Campman, SWANA division chairman and mana solid waste for Gannett Flemin Valley Forge, Pa , agrees it’s poss mulchers to pull out the treated “We have a client that makes i t mulch that pulls out [treated WO

and ships it to a landfill,” he S J ~ .

the facility receives materials, it 1s on a sorting line so that unwante items, including plastic and glass, be pulled out then sent to the land

But setting up a sorting SYS

“Yes it’s true some wood is difficu

W a s t e A B e

reqvires additional setup and labor costs for many facilities.

And while separation may be possible for mulchers, Hinkley says it may not be as easy at WTE facilities. “If a 100-yard truck goes by where you’re grinding huge amounts of wood, good grief. But such a facility could say it will only take new, white wood so that you could visibly see whether or not the wood is treated.”

There are other options to help distin- guish CCA-treated wood. Surface stain- ing methods can be used, but time constraints limit their application to small volumes of wood, and they are best used to “spot-check” fuel quality at wood recycling and burning facilities, according to Florida research. Detection systems - X-ray fluorescence (XRF) or laser - may be incorporated into a conveyor system at a processing facility. However, these systems are not commer- cially available and are only now being studied by a few Florida counties.

Even givenseparation’s feasibility, sort- ing CCA wood from other C&D debris relies on education and compliance.

Waste Minimization Fortunately, other products are avail-

able. There are arsenic- and chro- mium-free wood preservatives, such as alkaline copper quat (ACQ). One focus of the ongoing Florida research is what impact these other water-borne preser- vatives have. Obviously there are no benefits to switching if 30 years down the road the industry realizes that these chemicals pose a different problem, Townsend says.

An ever better choice, at least for the waste industry, is plastic lumber, which is comprised of recycled plastics such as drink bottles.

“The good news is that this is a fas- cinating issue and we’re moving in a good direction in terms of replacing CCA-treated wood,” Hinkley says. “On the disposal side, the industry is begin- ning to recognize the big picture of concerns, and steps will have to be taken, for example, keeping it out of mulch. Ash will have to be tested and monitored and possibly taken to a lined landfill, and we’ll have to look at the exemption to determine whether it should continue to go to an unlined C&D landfill.

“Unfortunately, this could cause con- siderable expense,” Hinkley continues.

“But do we wait until it‘s too late or handle it now? If we wait until we get hit in groundwater detection wells, it’ll be 20 years down the road, and we won’t have any choices. We know enough from other contaminated sites that if you’re forced into pump and treat remediation, cleanup is very costly. So we’re looking at this as an ounce of pre-

WA vention is a pound of cure.”

Patricia-Anne Tom IS Waste Age’s man- aging editor.

For More Information

H * A * Pa P * Y H A * U * L* I N G

I Circle No. 27 on Reader Service Card , I A u g u s t 2 0 0 1 w w w . w a s t e a g e . c o m 51