supplemental study for year 3

Supplemental Study for Year 3

Project Completed

Reason for Supplemental Study

Accelerate new lines of research which were identified in August 1999 during the deliberations concerning a ban on CCA in Minnesota

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

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 Tests Toxicity 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 stores TCLP SPLP Particle Size

One sample TCLP, 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 wastes 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.

Leaching Tests

10 samples of new CCA-treated dimensional lumber were collected from retail outlets

The wood was processed into 4 different sizes

TCLP and SPLP performed on all samples Additional leaching tests (EP Tox, MEP,

WET) were performed on one sample.

Figure IV.3: SPLP Extraction Results for As, Cu, and Cr from Saw Dust

0

1

2

3

4

5

6

7

8

9

Brand1 (2x4)

Brand1 (2x6)

Brand1 (2x8)

Brand1 (4x4)

Brand2 (4x4)

Brand3 (2x4)

Brand3 (2x6)

Brand4 (2x4)

Brand4 (2x6)

Brand5 (2x4)

Co

nc

en

tra

tio

n (

mg

/L) As

Cu

Cr

0.25 pcf 0.4 pcf

Figure IV.6: SPLP Extraction Results for As, Cu, and Cr from 1, 100-g Block

0

1

2

3

Brand1 (2x4)

Brand1 (2x6)

Brand1 (2x8)

Brand1 (4x4)

Brand2 (4x4)

Brand3 (2x4)

Brand3 (2x6)

Brand4 (2x4)

Brand4 (2x6)

Brand5 (2x4)

Co

nc

en

tra

tio

n (

mg

/L)

AsCuCr

0.25 pcf 0.4 pcf

Figure IV.7: TCLP Extraction Results for As, Cu, and Cr from Sawdust

0

2

4

6

8

10

12

14

16

18

Brand1 (2x4)

Brand1 (2x6)

Brand1 (2x8)

Brand1 (4x4)

Brand2 (4x4)

Brand3 (2x4)

Brand3 (2x6)

Brand4 (2x4)

Brand4 (2x6)

Brand5 (2x4)

Co

nc

en

tra

tio

n (

mg

/L)

As

Cu

Cr

0.25 pcf 0.4 pcf

Figure IV.10: TCLP Extraction Results for As, Cu, and Cr from 100-g Block

0

1

2

3

4

Brand 1(2x4)

Brand 1(2x6)

Brand 1(2x8)

Brand 1(4x4)

Brand 2(4x4)

Brand 3(2x4)

Brand 3(2x6)

Brand 4(2x4)

Brand 4(2x6)

Brand 5(2x4)

Co

nc

en

tra

tio

n (

mg

/L) As

CuCr

0.25 pcf 0.4 pcf

Figure IV.11: Arsenic Concentration in Extracts from TCLP, SPLP, EPTOX, and WET

0

5

10

15

20

25

30

35

40

TCLP SPLP EPTOX WET

As, C

oncentr

atio

n (

mg/L

)

Sawdust

Chipped Wood

5 20-g Blocks

100 g Block

Figure IV.14: MEP Test Results for Arsenic, Copper, and Chromium Using 3 20-g Blocks

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

1 3 5 7 9 11Time (Days)

Concentr

atio

n (

mg/L

)

Arsenic

Chromium

Copper

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

SPLP was performed on samples of processed wood from C&D debris recycling facilities

SPLP was also performed on several samples of other mulches, including commercial colored mulch

Table IV.7: Samples Exceeding the GWCTL

Samples

Number of Samples

Number of Samples

Exceeding As GWCTL

Number of Samples

Exceeding Cr GWCTL

1997 C&D Debris Samples (Sites A through M, except D2 and D4)

18 16 5

1999 C&D Debris Mulch Sample (Site N)

2 2 0

Yard Waste Facility (Site R, D2, D4)

3 1 1

Commercial Mulch (pine bark, cypress)

(Sites S, T, U) 3 0 0

Colored Mulch 1 (Site P)

1 0 0

Colored Mulch 2 (Site Q)

2 2 0

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%.

Questions?

Task 2: Major Use Sectors

Objectives

Estimate the distribution of CCA within different use sectors Production & disposal by product type Total amount of As currently in service Breakdown use – U.S. Statistics

- Florida Statistics

(utility poles/docks)

Production and Disposal By Product Type (Florida)

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

Production and Disposal By Product Type (Florida)

0

1

2

3

1960 1980 2000 2020 2040

Year

CC

A-T

rea

ted

Wo

od

(m

illio

n c

ub

ic f

t)Production:

Pole & Crossties

Disposal:Pole & Crossties

Amount of As Currently In Service

0

20000

40000

60000

80000

100000

19

60

19

70

19

80

19

90

20

00

20

10

20

20

20

30

20

40

Year

Cu

mu

lati

ve

As

(to

ns

)

Imported(or sold in FL)

Disposed

NetIn-Service

1,800 tons

28,600 tons

Net26,800 tons

Florida Statistics

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

U.S. Southern Pine Markets (From SFPA)

36%

8% 15%

18%

10%

Outdoor Decks, 36%

Marine, 18%Landscape,

15%

Highw ay, 10%

Fences, 8%

Other, 7%

From SFPA

Florida Use Statistics

FocusUtility PolesDocks (Marine & Freshwater)

Utility Poles

CCA-Treated Utility Poles In Florida (1961-2000)

Purchased Disposed In-Service

Units

Method 1 Method 2 Method 1 Method 2 Method 1 Method 2 Million ft3 26.1 21.6 0.7 0.5 25.4 21.1 Tons, As 1720 1430 43 36 1680 1390

Method 1 Method 2 % Arsenic within Utility Poles Versus Arsenic in All Treated Wood Products 6.3 5.2

Residential Docks

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

Material distribution in Alachua County Docks

no CCA5%

other + CCA 5%

concrete + CCA5%

only unknown wood29%

only CCA57%

Predominantly Freshwater Docks

only CCA31%

unspecified mat'l14%

only unknown

wood55%

Material distribution in Leon County Docks

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

Results

Units CCA-Treated Wood Used for Salt and Fresh

Water Applications

ft3 22 million tons, As 4,220 % Arsenic Uses for Marine and Salt Water Applications Versus Arsenic in All Treated Wood Products

16%

Conclusions

Majority of wood sold in the form of lumber & timbers

Disposal of lumber & timbers should peak by 2020

Disposal of utility poles not yet observed in significant quantities -- >Current pole recycling/reuse operations will not be likely able to handle the decommissioning of major lines

Conclusions (con’d)

Amount of arsenic currently in service due to CCA is 26,800 tons (estimated) This quantity can significantly impact water & soil

if not disposed properly.

Management plan needed to recover as much of the As as feasible.

Conclusions (con’d)Marine &

Freshwater Applications

16%

Outdoor Decks, Landscaping,

Fences, & Highway

Construction

Utility Poles5%

Alternative ChemicalTreated Wood Available for These Uses

79%

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 (to confirm CCA retention)

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 0.206 positive

MiamiAD 9 0.261 positiveTP 6 0.206 positiveOP 14 (0.005-0.54) 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

0

20

40

60

80

100

120

0 5 10 15 20 25 30

Average % Volatile

Ave

rag

e A

s co

nc.

TP

OP

LT

MG

TB

AD BP

PP

BR

Percent volatile vs. As conc

Bivens Arm Park, Gainesville

0

20

40

60

80

100

120

S01 S02 S03 S04 S05 S06 S07 S08 C01 C02 C03 C04 C05 C06 C07 C08

As

Co

nce

ntr

atio

n (

mg

/kg

)

0

10

20

30

40

50

60

70

80

% V

ola

tile

As

% Volatile

Deck Soils Control Soils

Metal Concentrations in Soil Under Sampled Decks

Arsenic 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

Table II.2: Arsenic Results for Surface Soils

Surface Soil Samples Collected Below Decks (all analyses above detection limit)

Controls (above detection

limit)

Controls (BDL1 = 0)

Location N

Average (mg/kg)

Std. Dev. (mg/kg)

Max. (mg/kg)

Min. (mg/kg)

N Average (mg/kg)

N Average (mg/kg)

Gainesville BP 8 41.6 22.8 87.9 15.6 8 2.61 8 2.61 BR 9 10.7 9.15 33.2 4.05 5 0.46 9 0.26 PP 8 9.56 4.50 18.1 3.54 4 1.03 8 0.52 total samples 25 20.2 20.2 87.9 3.54 17 1.61 25 1.09 Tallahassee TB 8 17.2 7.72 31.0 8.59 8 2.31 8 2.31 MG 8 34.0 13.7 48.8 5.09 8 1.42 8 1.42 LT 8 0.48 0.14 0.62 0.25 8 0.47 8 0.47 total samples2 16 25.6 13.8 48.8 5.09 16 1.86 16 1.86 Miami AD 8 33.9 20.7 81.2 15.5 8 1.98 8 1.98 TP 8 4.30 2.32 7.47 1.18 8 1.13 8 1.13 OP 8 79.1 60.7 217 31.7 8 0.66 8 0.66 total samples 24 39.1 47.3 217 1.18 24 1.26 24 1.26 All Sites2 65 28.5 32.8 217 1.18 57 1.53 65 1.34

1BDL=Below Detection Limit. Detection limit is 0.25 mg/kg based on sample dry mass of 2.0 g 2Does not include results from Lake Talquin, LT, deck

Figure II.1: Comparison of Mean Deck Arsenic Soil Concentration versus Control Soil Concentrations

0

10

20

30

40

50

60

70

80

90

BP BR PP LT TB MG AD TP OP

Ars

en

ic C

on

ce

ntr

ati

on

(m

g/k

g)

Control Under Deck

Gainesville MiamiTallahassee

Figure II.3: Comparison of Mean Deck Soil Chromium Concentration versus Control Soil Concentrations

0

10

20

30

40

50

60

70

80

BP BR PP LT TB MG AD TP OP

Ch

rom

ium

Co

nc

en

tra

tio

n (

mg

/kg

)

Control Under Deck

Gainesville MiamiTallahassee

Figure II.5: Comparison of Mean Deck Soil Copper Concentration versus Control Soil Concentrations

0

20

40

60

80

100

120

BP BR PP LT TB MG AD TP OP

Co

pp

er

Co

nce

ntr

ati

on

(m

g/k

g)

Control Under Deck

Gainesville MiamiTallahassee

Figure II.10: Average of Soil Cores (As only)

0

2

4

6

8

10

12

0 10 20 30 40 50 60 70 80

Arsenic Concentration (mg/kg)

Figure II.11: Log of Arsenic Concentrations

0

1

10

100

1000

Lo

g (

Ars

enic

Co

nce

ntr

atio

n (

mg

/kg

))

LT

Residential

Industiral

Leaching

Average

TB

MG

BP

BR

PP

TP

OP

AD

Residential

Industrial

Average

Leaching

Areal Extent of Potential Impact

An estimate of the area of soil impacted by CCA-treated decks was performed (see page 28).

Approximate 25,000 acres of Florida land covered by CCA-treated decks (39 square miles).

Top 8 inches of this area would correspond to 60 million tons of soil.

0

50

100

150

200

250

300

350

400

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

% Leaching

Soi

l As

Con

cen

trat

ion

(m

g/k

g)

2 inch 4 inch

8 inch

12 inch

Potential Soil Arsenic Concentrations Under Decks

Questions?

Draft of Final Report

Available at www.ccaresearch.org

Comments to be accepted through January 21, 2001

Questions?