History of Research Project on CCA-Treated Wood Presented July 9, 2001 Sarasota County, Florida

History of Research Project on CCA-Treated Wood

Presented July 9, 2001Sarasota County, Florida

Funding Received from

Florida Center for Solid and Hazardous Waste Mngt.

Florida Power and Light

and Sarasota County

Helena Solo-Gabriele, Ph.D., P.E.,

Assoc. Prof., Civil/Environ. Engrg

Timothy Townsend, Ph.D.

Assoc. Prof., Environ/Solid Waste Engrg

David Hahn, Ph.D.

Assist. Prof., Mechanical Engrg.

Yong Cai, Ph.D.

Assist. Prof., Chemistry

Faculty Researchers

Students Supported on Project Sean Bennie Vandin Calitu Kelvin Gary Naila Hosein Gary Jacobi Bernine Khan Monika Kormienko Jennifer Penha Catalina Santamaria Donna May Sakura

Jenna Jambeck Tim Franklin Brian Messick Jin-Kun Song Kristin Stook (recent graduate) Thabet Tolaymat

Background

CCA-Treated Wood is the most common wood preservative used today (>80% market)

CCA ---> Chromated Copper Arsenate

Background

Above Ground

Structural PolesSaltwater Splash

Saltwater ImmersionPole/Pilings

pcf = pounds of CCA per cubic foot of wood

Background

CCA ---> Chromated Copper ArsenateThe treated wood contains very high concentrations of Cr, Cu, and As

As toxic, known carcinogen

Soil background levels for arsenic in Florida are low

Strict disposal guidelines

Why Was this Project Initiated?

High metals concentrations were observed in the ash from wood cogeneration facilities located in Florida

Year 1 (1996-1997)

Year 1: Disposal Forecast

0

5

10

15

20

25

30

351

96

4

19

68

19

72

19

76

19

80

19

84

19

88

19

92

19

96

20

00

20

04

20

08

20

12

20

16

20

20

20

24

20

28

20

32

20

36

20

40

20

44

Year

Mill

ion

ft3

, d

isp

ose

d

No Change in CCA Use

Today Hypothetical Case

Hypothetical CaseIf 100% Alt. Chem.Used by 2002

C&D LandfillMSW Landfill

C&D Debris Recycling Facilities

CCA-WoodRemoved

from Service

Processed Wood (6% CCA in 1996)

Land Application

Wood Fuel Facility Ash

Year 2 (1997-1998)

Year 2

Develop Tools for Disposal End Management

Leaching Studies, ash Hazardous when CCA-treated wood represents

5% of wood burned

Solvents can extract metals from ash, citric acid very promising (40 to 100% As removed) ------> Explore Potential Recycling?

Year 2 (continued)

Sorting Studies, Laboratory Chemical stains, low capital cost

labor intensive

X-ray methods, high capital costsuitable for on-line system

Untreated Treated

Year 3 (1998-1999)

Year 3

Disposal-End Management

Field Demonstration of Sorting Technologies Stains suitable for sorting small quantities of wood

Evaluation of Pyrolysis Technology Appears promising for ultimate disposal

Resource book for Wood Disposal Sector

Year 3 (Continued) Alternative Chemicals

Four Promising Alternative Chemicals for CCA: ACQ, CBA, CC, CDDC

All standardized for applications requiring 0.25 & 0.4 pcf Comparable to CCA: efficacy

Leach less As but generally more Cu

Cost 10 to 30% more at retail establishment

Ash Problem

Inventory

SortingLab

Ash Char & Trt

SortingField

Alt. Chem.Lit Review

On-going On-going

The Research Team Was Invited to the Minnesota Proceedings

Minnesota’s Listed Metals Advisory Council[Cd, Pb, Hg, and Cr(VI)]

Speciation Debated

In-Service Issues Debated

Lack of Scientific Data

Year 3 Supplemental

Impacts of CCA on Soil during In-Service Use

Use Sectors for CCA-Treated Wood

Leaching of CCA-treated Wood and C&D Debris Wood Mulch

Literature Reviews, Alt. Chem.Cr & As Speciation

Minnesota

Lit ReviewsAlt Chem, As, Cr Spec

DeckStudy

Leaching Wood & Mulch

UseSectors

Leaching of CCA During In-Service Use

Year 3 Supplemental

Leaching of CCA-Treated Wood During In-Service Use

Year 3 Supplemental

Chemicals Do Leach from CCA-treated Wood During In-Service Use

Leaching of CCA-Treated Wood During In-Service Use

0

10

20

30

40

50

60

70

80

90

BP BR PP LT TB MG AD TP OP

Ars

en

ic C

on

cen

tra

tio

n (

mg

/kg

)

Control Under Deck

Gainesville MiamiTallahasseeNot CCA-Treated

FDEP Industrial SCTL

Leaching of CCA-Treated Wood During In-Service Use

0

2

4

6

8

10

12

0 10 20 30 40 50 60 70 80

Arsenic Concentration (mg/kg)

Approximately 39 square miles of Florida land covered by CCA-treated decks. Top 8 inches of this area would correspond to 60 million tons of soil.

Use Sectors for CCA-Treated Wood

Year 3 Supplemental

Use Sectors for CCA-Treated Wood

0

10

20

30

40

1960 1980 2000 2020 2040Year

CC

A-T

rea

ted

Wo

od

(m

illio

n c

ub

ic f

t)

Disposal:Lumber &Timbers

Production: Lumber & Timbers

Disposal:Poles & Crossties

Production

Use Sectors for CCA-Treated Wood

Marine & Freshwater Applications

16%

Outdoor Decks, Landscaping,

Fences, & Highway

Construction

Utility Poles5%

Alternative ChemicalTreated Wood Available for These Uses

79%

Year 3 Supplemental

28,600 tons of As, Cumulative

1600 tons Asimported per year In-service losses (10%):

2900 tons

Disposed to date:1600 tons

Future disposal(for that imported through 2000):

24,100 tons

Year 3 Supplemental

Leaching of CCA-treated Wood and

C&D Debris Wood Mulch

Year 3 Supplemental

Leaching of CCA-Treated Wood

0

5

10

15

20

25

30

35

40

TCLP SPLP EPTOX WET

As

Co

nce

ntr

atio

n (

mg

/L)

Sawdust

Chipped Wood

5 20-g Blocks

100-g Block

Leaching of Mulch

Samples No. No. Exceeding GWCTL for As

No. Exceeding GWCTL for Cr

C&D Debris 20 18 5

Yard Waste 3 1 1

Colored Mulch

3 2 0

Vegetative Mulch

3 0 0

Year 3 Supplemental

Ash Problem

Inventory

SortingLab

Ash Char & Trt

SortingField

Alt. Chem.Lit Review

Minnesota

Lit ReviewAlt Chem, As, Cr Spec

DeckStudy

On-going

Leaching Wood & Mulch

UseSectors

On-going

Alt. Chem.Leaching

Alt. Chem.Toxicity

As Spec.Lysimeters

TCLP - unburned

As SpecGW @ LF

Recently Funded

On-going

As Spec.Lysimeters (cond)

TCLP - ash

As Reserviors

Sorting Study

On-going On-going

Cr Spec

On-going

Questions?Comments?