Supplemental Study for Year 3

Reason for Supplemental Study

Accelerate new lines of research.

Tasks Assoc. with Supplemental Funds

In-Service Issues

Disposal

Literature Review

Depletion of Cr, Cu, and As during the service life of CCA-treated wood (task 1)

Quantity of CCA-treated wood used by major industries (task 2)

TCLP and SPLP tests for unburned CCA-treated wood (task 5)

Laboratory Methods for Cr and As speciation (task 3) Identify laboratory methods for organics analysis assoc. with

alternative chemicals (task 4)

Task 5:

TCLP and SPLP Tests on Unburned CCA-Treated Wood

CCA-Treated Wood and Mulch Leaching Tests

Background

Year 1 Study -- Collected samples of processed wood from C&D debris recycling facilities in Florida. Found that approximately 6% of wood stream was CCA-treated.

Year 2 Study -- Characterized ash from the combustion of CCA-treated wood and wood mixtures. Found that the presence of 5% CCA-treated wood caused ash to fail TCLP and be characterized as a hazardous waste.

Background

No leaching studies were conducted on unburned CCA-treated wood as part of year 1 and 2 studies.

When is Leaching a Concern?

Leaching during In-Service Use Leaching during Storage Leaching upon Reuse of Mulch Leaching during Disposal

Leaching Tests on Unburned CCA-Treated Wood in Year 3 Supplemental Project

Leaching of new CCA-treated wood using standardized regulatory leaching tests

Leaching of wood mulch produced by C&D debris recycling operations

Leaching of new CCA-treated wood using standardized regulatory leaching tests

Types of Leaching Tests

Batch TestsToxicity Characteristic Leaching Procedure

(TCLP)Synthetic Precipitation Leaching Procedure

(SPLP) Column Tests Field Tests

Testing Results to be Discussed

Ten samples of CCA-treated wood purchased from home supply storesTCLPSPLPParticle Size

One sampleTCLP, SPLP, EP, WET, MEP

Reminder for Arsenic

Toxicity CharacteristicArsenic: 5 mg/lChromium: 5 mg/l

Groundwater Cleanup Target LevelArsenic: 0.05 mg/lChromium: 0.10 mg/lCopper: 1 mg/l

How are TCLP and SPLP Tests Applied?

TCLP: To determine if solid waste is hazardous by toxicity characteristic. Note: Discarded arsenical-treated wood is exempt under RCRA.

TCLP: To determine is hazardous waste can be land disposed.

SPLP: To determine if land-applied waste or contaminated soil presents a risk to groundwater from chemical leaching.

TCLP and SPLP

•Batch tests.

•TCLP: Municipal Landfill•SPLP: Acidic Rain

•100 g of waste per 2 L of leaching solution.

•Extracted for 18 hours.

•Leachate if filtered and analyzed.

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14

A B C D E F G H I J

Co

nce

ntr

atio

n (

mg

/L)

TCLP: Arsenic(Sawdust)

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0.5

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/L)

TCLP: Chromium(Sawdust)

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TCLP: Copper(Sawdust)

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nc

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/l)

SPLP: Arsenic(Sawdust)

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A B C D E F G H I J

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nc

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/l)

SPLP: Chromium(Sawdust)

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SPLP: Copper(Sawdust)

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/L)

Sawdust Chips 5 Blocks 1 Block

TCLP ArsenicImpact of Particle Size

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TCLP (mg/L)

SP

LP

(m

g/L

)

Comparison ofSPLP & TCLP (As)

0.0

1.0

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0.0 5.0 10.0 15.0 20.0

Concentration TCLP (mg/L)

Co

nce

ntr

atio

n S

PL

P (

mg

/L)

Comparison ofSPLP & TCLP (Cu)

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Ars

enic

(m

g/L

)

TCLP SPLP EP WET

Comparison ofBatch Leaching Tests

(Arsenic)

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0 2 4 6 8 10Time (Days)

As

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nce

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/L)

Multiple Extraction Procedure(Arsenic)

Implications of Leaching Tests

Without the exclusion, CCA-treated wood would often be a characteristic hazardous waste.

If SPLP results are compared to GWCTLs, should not be disposed in an unlined landfill (based on current policy for other wastes).

What About Reuse Outside the Landfill (wood mulch)?

Mulch Bagging Operation

Leaching from Land Applied Mulch

The SPLP is the test most commonly used to assess leaching from a land applied waste.

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Ob

serv

ati

on

s

0 50 100 200 300 400 500 600Arsenic Concentration (ug/l)

C&D Wood MulchAs in SPLP LeachatesTotal Samples: 58Mean: 153 ug/lRange: 21 to 658 ug/l51 Samples > 50 ug/l

Implications for Mulch

When considering SPLP leaching, CCA-treated wood must be present at levels of less than 1% in wood mulch to meet current groundwater standards.

Most C&D wood samples are already greater than 1%.

Task 2: Major Use Sectors

Cumulative Arsenic Quantities

0

10000

20000

30000

40000

50000

60000

70000

1970

1980

1990

2000

2010

2020

2030

Year

Cu

mu

lati

ve A

s (t

on

s)

28,800 tons

2,500 tons

Net26,300 tons

Imported

Disposed

Florida Production

0

510

15

2025

30

35

4045

5019

64

1967

1970

1973

1976

1979

1982

1985

1988

1991

1994

1997

2000

Mil

lio

n c

ub

ic f

ee

t

Total

L&T

Other

AWPI, 94

PolesFenceCross Ties

CCA-Treated Wood Production, Florida

U.S. Southern Pine Markets

Outdoor Decks

LandscapeFences

Marine

Highw ay

Foundations

Framing

Export

Other

(From SFPA)

36%

8% 15%

18%

10%

Double-Check Values for Florida

FocusTransportation SectorUtility PolesDocks

Transportation Sector

Initial contact with FDOT Districts

Utility Poles

Compiled volume of treated wood for 1998 from questionnaires sent out last year

Scaled data by population served Scaled 1998 data against US historical

pole production statistics

Preliminary Results1600 tons of As (Cumulative)6% of all As associated with CCA-treated

wood that is currently in service

Utility Poles

Residential Docks

Evaluated data for 3 counties (Alachua, Dade and Leon)

For each county, weObtained copies of dock building permitsContacted the Property Appraisers OfficeReviewed aerial photographs Contacted dock manufacturers

Results from permits Alachua

41 permits reviewed Approx 486 (freshwater) docks permitted since recording in

1994 Dade

100 permits reviewed Approx 6000 (marine) docks permitted since recording in 1980

Leon 71 permits reviewed Approx 450 (freshwater) docks permitted since recording

began in 1993

Material distribution in Alachua County Docks

no CCA5%

other + CCA 5%

concrete + CCA5%

only unknown wood29%

only CCA57%

Predominantly Freshwater Docks

Material distribution in Dade County Docks

only CCA49%

only unknown wood11%

only concrete9%

CCA + all other15%

concrete + all other9%

no CCA7%

Predominantly Salt water Docks

Material distribution in Leon County Docks

only unknown wood55%

all other14%

only CCA31%

Predominantly Freshwater Docks

Preliminary Results

Obtained Typical Retention Levels Average Dock Size (Surface Area) Typical Design Scale Data to County Population

Numbers Computed Appear Low

Possible Reasons for Small No.

Not all docks have been permitted Other marine applications (Piers, Bulkheads,

etc…. SFPA estimates that docks represent 32% of

marine applications

Task 1: Depletion During Service Life

Task 1: Depletion During Service Life

Methods

Literature Review Sample Soils Below CCA-Treated Decks Analyze Soil Samples

Task 1: Depletion During Service Life

A total of nine decks sampled 3 in Gainesville 3 in Miami 2 in Tallahassee (1 other deck sampled, not CCA-treated)

Samples collected in a grid-like fashion below each deck Initially, at least 2 background samples were collected near

each deck. Later, a total of 8 were collected A core sample/sawdust collected

Sample soils below CCA-Treated Decks

Gainesville Decks

Paynes Prairie

Foot Bridge at NW 34th St

Bivens Arm Park

Miami Decks

A.D. Barnes Park

Oleta River Park

Tropical Park

Tallahassee Decks

Lake Talquin

Tom Brown Park

Maclay Gardens

Sampling Grid

Soil Core

Stains, wood bore, &Sawdust

XRF Analysis by Robbins Manufacturing

Deck Retention LevelsSample Deck Age,yrs XRF Result,pcf StainsGainesville

BR 5 0.755 positiveBP 14 0.477 positivePP 15 positive

MiamiAD 9 0.261 positiveTP 6 0.206 positiveOP 14 positive

TallahasseeMG 4 0.412 positiveLT 19 0.008 negativeTB 2 0.247 positive

Grain Size Analysis

Sample ID Avg. Grain size (mm)

GainesvilleBR 0.343BP 0.387PP 0.370

MiamiAD 0.339TP 0.284OP 0.293

TallahasseeMG 0.387LT 0.393TB 0.390

Volatiles vs. As concentration

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Average % Volatile

Ave

rage

As

conc

.

TP

OP

LT

MG

TB

AD BP

PP

BR

Percent volatile vs. As conc (Tal)

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45.0

TBS01(T)

TBS02(T)

TBS03(T)

TBS04(T)

TBS05(T)

TBS06(T)

TBS07(T)

TBS08(T)

TBCtrl 1

TBCtrl 2

mg

/kg

of

As

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% V

ola

tile

As

% Volatile

Metal Concentrations in Soil Under Sampled Decks

Background Information

The Florida Department of Environmental Protection has developed a set of risk-based concentration levels of chemicals in soil:

The Soil Cleanup Target Levels (SCTL) Direct Exposure

Residential SCTL for As is 0.8 mg/kg. Industrial SCTL for As is 3.7 mg/kg.

Background Information

The naturally occurring As concentration in Florida soils has been measured (Ma et al. 1999).

Geometric Mean = 0.42 mg/kg 73% of soil samples were less than 0.8 mg/kg >90% of soil samples were less than 3.7 mg/kg

Summary

The mean As concentration under 8 of the 9 decks exceeded the industrial Florida SCTL of 3.7 mg/kg.

Sixty one of 73 of the individual soil samples exceeded the industrial Florida SCTL.

Additional Sample Collection

Additional control samples were collected and analyzed to assist with statistical comparison

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BPC01 BPC02 BP01 BP02 BP03 BP04 BP05 BP06 BP07 BP08

Ars

enic

Co

nce

ntr

atio

n (

mg

/kg

)Gainesville Site BPDeck Samples: As = 41.6 mg/kg (n = 8)Control: As = 7.0 mg/kg (n = 2)

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100A

rsen

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once

ntra

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(mg/

kg)

Gainesville Site BPDeck Samples: As = 41.6 mg/kg (n = 8)Control: As = 2.6 mg/kg (n = 8)

Copper and Chromium Analysis

Analysis of Copper and Chromium has been completed

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0 50 100 150 200 250

As (mg/kg)

Cr

(mg

/kg

)Comparison of Chromium

and Arsenic

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250

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As (mg/kg)

Cu

(m

g/k

g)

Comparison of Copperand Arsenic

Soil Cores

One soil core was collected from underneath each deck

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1

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6

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Metal Concentration (mg/kg)D

ep

th (

in)

Miami Site OPSoil Core Data

• Arsenic

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1

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6

0 20 40 60 80

Metal Concentration (mg/kg)D

epth

(in

)

Miami Site OPSoil Core Data

• Arsenic

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6

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Metal Concentration (mg/kg)D

ep

th (

in)

Miami Site OPSoil Core Data

• Arsenic• Chromium

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6

0 20 40 60 80

Metal Concentration (mg/kg)D

ep

th (

in)

Miami Site OPSoil Core Data

• Arsenic• Chromium

• Copper

Questions?