Background Concentrations of Metals,a Progress Report

Bruce Garbaccio, P.G.Engineering Geologist

Department of Toxic Substances ControlGeological Services Unit, Glendale

Background Data Sources

• United States USGS P 1648 (2001)

• California Kearney Report (1996)

• Los Angeles Basin LAUSD Arsenic Study

• Site Specific Data Sets

Background Data ConcentrationsCalifornia Statewide Los Angeles Basin

Sb 0.15 – 1.95 0.2 – 1.5(0.33 – 0.73)

As 0.6 – 11 1 - 6

Cd 0.05 – 1.70 0.2 – 1(0.15-0.44)

Pb 12.4 – 97.1 1 – 20(21 – 26.7)

Cr 23 – 1579 0 – 40(45 – 115)

Ni 9 – 509 0 – 40(21 – 56)

Zn 88 – 236 20 – 150(133-170)

Chromium Variation Los Angeles Area

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45

0 2 4 6 8 10 12

Site

Con

cent

ratio

n (m

g/kg

)

SSL-497

Bell New Elem.

Jeff #1

Gabrieleno San Gab

Valle Lindo El Monte

Van Nuys NE #1

North H NE #3

Germain Chatsw orth

Arminta North H

Gratts

Cr concentrations at 10 LA Basin sites

Kearney Lead

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4

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16

5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

Series1

Histogram of Pb concentrations in California soils

Cleanup Guidelines

Cal EPACHHSLResidential Industrial

USEPAPRG

Residential Industrial

LAUSD

Sb

As

30 380

0.07 0.24

30 750

0.38 3.0 6

Cd 1.7 7.5 37 930(Cal mod 9.0)

Cr

Pb

100,000

150 3,500

210 450

400 1000(Cal mod 130)

255

Ni 1,600 16,000

Zn 23,000 100,000

Anthropogenic Sources of Metals

• Pb lead based paint• Automobile exhaust• automobile batteries

• Cr Plating solutionsStainless steel scrap

• As pesticide/herbicide application

Common Geologic Associations

• Ultramafic Rocks Mg-Cr-Ni-Co-Cu-V

• Epithermal Gold Au-As-Sb-Hg

• Volcanogenic Massive Sulphide Cu-Zn-Pb

• K/Rb Ca/Sr Zn/Cd As/Sb

Positive correlation of Cr and Ni in soil

Statewide (Kearney) Cr vs Ni

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450

0 10 20 30 40 50 60

Con

cent

ratio

n (m

g/kg

)

Ni

Cr

Epithermal Gold Deposits

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0 2 4 6 8 10 12 14 16 18 20

Con

cent

ratio

n (m

g/kg

)

AsSb

As and Sb concentrations in Epithermal Gold Deposits

California (Kearney)

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1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49

Con

cent

ratio

n (m

g/kg

)

Cd X 100Zn

Relationship of Cd with Increasing Zn in California Soils

Anthropogenic Associations

• Lead Batteries Pb / Sb• Scrap Metal

– Bronze Cu-Zn– Brass Cu-Sn– Stainless Steel Fe-Cr-Mo-V

Western Metal

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10000

20000

30000

40000

50000

60000

70000

80000

1 2 3 4 5 6 7 8 9 10

Con

cent

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LeadAntimony X 10

Correlation of Pb and Sb in SoilUsed Automobile Battery Recycling Facility

SELC South Gate Plating Shop

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15000

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25000

30000

35000

40000

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cent

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Cr

Ni

Cr and Ni variation in soil, former plating shop,South Gate

SRHS 2 Railroad Easement 2

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cent

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Sb

As

As and Sb in soil, former railroad line,Los Angeles

Non-Point Sources

• Automobile Exhaust Pb

• Pesticide/Herbicide Application As

Los Angeles Area Lead Variation

0

20

40

60

80

100

120

140

160

0 1 2 3 4 5 6 7 8 9 10

Site

Con

cent

rtat

ion

(mg/

kg) SSL-497

Bell New Elem

Jeff #1

Valle Lindo El Monte

North H NE #3

Germain Chatsw orth

Arminta North H

Pb concentrations, surface and subsurface samples,Los Angeles Basin

Lead LA-SG-SF 5 foot data

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5

10

15

20

25

0 1 2 3 4 5 6 7 8 9 10

Con

cent

ratio

n (m

g/kg

)

SSL-497

Bell New

Jeff #1

Gabrieleno

Van Nuys

North H

Germain

Arminta

Pb concentrations, 5-foot depthLos Angeles Basin

Summary

• Site Specific and Regional Geology may have an influence on metals concentrations

• Anthropogenic impacts may mask true background

• All data should be evaluated to help differentiate between geologic and anthropogenic associations

Questions and Comments