### 37597 4 

# FIL E PLA N INTERI M STATU S REPOR T CONSOLIDATE D FINDING S O F SOIL-LEA D INVESTIGATION S A T T H E CALIFORNI A GULC H NP L SIT E VOLUM E H — APPENDICE S Jun e 1996

U.S

. Environmenta l Protectio n Agenc y Regio n VI H On e Denve r Plac e 99 9 18t h Street
, Suit e 50 0 Denver
, Colorad o 80202-240 5INTERI M STATU S REPOR T CONSOLIDATE D FINDING S O F SOIL-LEA D INVESTIGATION

S A T T H E CALIFORNI A GULC H NP L SIT E

Jun e 199 6 Prepare d fo r U.S

. Environmenta l Protectio n Agenc y Regio n V m On e Denve r Place 99 9 18t h Street
, Suit e 50 0 Denver
, Colorad o 80202-240 5 EP A Wor k Assignmen t No

. 04601-03 7 Documen t Contro l No

. 4800-37-020 5 Prepare d b y R O Y F

. WESTON
, INC

. 21 5 Unio n Blvd.
, Suit e 55 0 Lakewood
, Colorad o 80228-184 2APPENDI X A SOI L LEA D REMEDIA L INVESTIGATIO

NAPPENDI X A SOI L LEA D REMEDIA L INVESTIGATION TABL E O F CONTENT S 

### Sectio n Titl

e Pag

e A. 1 MAPPIN

G

..................................... . A- l A . 2 AI R PATHWA Y INVESTIGATIO

N (WCC
, 1992a )

........... .

A- 2 A.2. 1 Objective s ................................ . A- 2 A.2. 2 Method s .................................. . A- 3 

### A.2.2. 1 Meteorologica l

Measurement s ............. .

A- 3 A.2.2. 2 Ai r Qualit y Measurement s ............... .

A- 3 A.2. 3 Result s .................................. . A- 4 A.2.3. 1 Meteorologica l

Condition s ............... .

A- 4 A.2.3. 2 Ai r Qualit y Monitorin g ................. .

A- 7 A . 3 POPULATE

D STUD Y ARE A SURFAC E SOI L INVESTIGATION

S

. A- 8 

### A.3. 1 Stat e o f Colorad o Departmen t o f La w (E-S
, 1986 )

........ . A- 8 A.3.1. 1 Soi l Samplin g ..................... .

A-1 0 

### A.3.1. 2 Soi l Samplin g Metho d

................ .

A-l l A.3.1. 3 Chemica l Analysi s ................... .

A-l l A.3.1. 4 Soi l Surve y Result s .................. .

A-l l A.3. 2 Remedia l Investigatio n Repor t (CH 2 M Hill , 1987 )

....... . A-1 5 A.3.2. 1 Geolog y ......................... . A-1 5 A.3.2. 2 Soil s ........................... . A-1 7 

### A3.2. 3 Surfac e Wate r ..................... .

A-1 7 A.3.2. 4 Climat e ......................... . A-1 7 A.3.2. 5 Ai r Qualit y ....................... .

A-1 8 

### A.3.2. 6 Natur e an d Exten t o f Contaminatio n ........ . A-1 8 A.3. 3 Soil s Investigatio n i n th e Leadvill e Stud y Are a (Walsh , 1988 )

. A-2 5 A.3.3. 1 Method s ......................... . A-25 A.3.3. 2 Result s .......................... . A-2 6 A.3. 4 Residentia l Surfac e Soil s an d Househol d 

### Dus t Samplin g (Walsh , 1990 )

.................... .

A-2 7 A.3.4. 1 Samplin g Procedure s ................. .

A-2 7 A.3.4. 2 Samplin g Location s .................. .

A-2 8 A.3.4. 3 Analysi s o f Surfac e Soi l an d Dus t Sample s .... . A-2 8 A.3.4. 4 Result s .......................... . A-2 8 A.3. 5 Soil s Investigatio n Dat a Repor t (CDM
, 1993 )

.......... .

A-2 9 A.3.5. 1 Soil s Investigatio n Sampl e Location s ........ . A-2 9 A.3.5. 2 Soi l Samplin g ..................... .

A-3 0 

### A.3.5. 3 Samplin g Metho d

................... .

A-3 0 Residential-Populate d

Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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. epa\soils-ri\append-a.ju nAPPENDI X A TABL E O F CONTENT S (continued ) 

### Sectio n Titl

e Page A.3.5. 4 Analysi s o f Soi l Sample s ............... .

A-3 1 

### A.3.5. 5 Result s .......................... .

A-3 2 A.3. 6 Soil s Investigation , Californi a Gulc h Stud y Are a (Walsh , 1992a )

............................ . A-3 3 A.3.6. 1 Geolog y ......................... . A-3 4 A.3.6. 2 Soil s ........................... . A-3 4 

### A.3.6. 3 Soi l Samplin g ..................... .

A-3 5 A.3.6. 4 Soi l Samplin g Metho d

................ .

A-3 6 A.3.6. 5 Surficia l Geologi c Mappin g ............. .

A-3 6 

### A.3.6. 6 Laborator y Analysi s .................. .

A-3 7 A.3.6. 7 Result s .......................... . A-3 7 

### A.3. 7 Smelte r Remedia l Investigatio n Repor t (Walsh , 1993 )

..... . A-4 7 A.3.7. 1 Ai r Dispersio n Modelin g ............... .

A-4 8 

### A.3.7. 2 Smelte r Soi l Samplin g ................ .

A-4 8 A.3.7. 3 Area s Impacte d b y Smelte r Emission s ....... . A-4 9 A.3.7. 4 Result s .......................... . A-5 0 A.3. 8 Surfac e Wate r Remedia l Investigatio n Repor t (WCC
, 1993c )

. . A-5 8 

### A.3.8. 1 Surfac e Wate r Flo w Monitorin g an d Sampl e Collectio n Syste m Location s ............. .

A-5 9 

### A.3.8. 2 Surfac e Wate r an d Be d Material Samplin g .... . A-5 9 A.3.8. 3 Analysi s o f Surfac e Wate r an d Be d Material

... . A-6 0 A.3.8. 4 Natur e an d Exten t o f Contaminatio n ........ . A-6 0 

### A.3. 9 Metal Speciatio n and Sourc e Characterizatio n (Drexler
, 1995 )

............................ . A-6 4 A.3.1 0 WESTO N XR F Residentia l Surfac e Soil s Investigatio n (WESTON
, 1991b )

.......................... . A-6 5 A.3.10. 1 Samplin g ........................ .

A-6 6 A.3.10. 2 Result s .......................... . A-6 7 

### A.3.1 1 Dat a Repor t fo r Lea d Occurrenc e i n an d Immediatel y Adjacen t t o Residential Areas , Californi a Gulc h Site
, 

### Leadville
, Colorad o (Universit y o f Cincinnati
, 1991 )

...... . A-6 8 A.3.11. 1 Dat a Collectio n Proces s ............... .

A-6 9 A.3.11. 2 Sampl e Collectio n ................... .

A-6 9 

### A.3.11. 3 Interio r Dus t Samplin g ................ .

A-6 9 A.3.1 2 Pre-minin g Soil s Geochemistr y Repor t (Walsh , 1993 )

..... . A-7 0 A.3.12. 1 Geologi c Mappin g ................... .

A-7 1 A.3.12. 2 Method s fo r Estimatin g Pre-minin g 

### Soi l Metal Concentration s .............. .

A-7 1 

### A.3.12. 3 Developmen t o f Soil-Geologi c Unit s ........ . A-7 5 Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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. epa\soils-ri\append-a.ju n

### Sectio n APPENDI X A 

### TABL E O F CONTENT S (Continued ) Titl e Page A.3.12. 4 Distinguishin g Betwee n Disturbe d an d Undisturbe d Soil s ................... .

A-7 5 A.3.12. 5 Result s .......................... . A-7 7 

### A.3.12.5. 1 Backgroun d Metal Concentration s i n Landscap e Position s ....... . A-7 7 A.3.12.5. 2 Backgroun d Metal Concentration s i n Soil-Geologi c Unit s ......... .

A-7 8 

### A.3.12.5. 3 Metal Concentration s i n Disturbe d an d Undisturbe d Soil s .......... .

A-7 8 A 4 REFERENCE

S

................................. . A-8 3 LIS T O F FIGURE S Figur e Titl

e Page 

### A- l Colorad o Mountai n Colleg e Win d Rose
, Octobe r 1990—199 1

....... . A- 5 A- 2 Ya k Tunne l Win d Rose
, Octobe r 1990—199 1

................ .

A- 6 A- 3 Radia l Group s o f Soi l Sampl e Location s a s a Functio n o f Distanc e fro m Emission s Sources ..................... .

A-1 4 A- 4 Surfac e Wate r Paramete r Variance Alon g Californi a Gulc h

....... . A-2 4 

### A- 5 Cumulativ e

Probabilit y Plo t fo r P b fo r Soil s o f Alluvia l Landscap e Position s ............................... . A-7 4 LIS T O F TABLE S Tabl e No

. Titl

e Pag e 

### A- l PM-1 0 Lea d Mea n Concentratio n ........................ .

A- 9 A- 2 Soi l Lea d Concentration s i n Stud y Area s o f Leadville
, Stringtown
, an d Contro l Are a ................................. . A-1 2 Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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. epa\soils-ri\append-a.ju nAPPENDI X A TABL E O F CONTENT S (Continued ) LIS T O F TABLE S (Continued ) Tabl e No

. Titl

e Pag e A- 3 Mos t Prominen t Mineral s o f th e Or e Deposit s o f th e Leadvill e Minin g District..........................

. A-1 6 A- 4 Soil/Sedimen t

Sample s ............................. . A-2 0 

### A- 5 Surfac e Wate r Flo w Rate s an d pH , Californi a Gulch-Arkansa s Rive r A t Hig h an d Lo w Flo w Period s ........................ .

A-2 2 

### A- 6 Meta l Concentrations
, Californi a Gulc h - Arkansa s Rive r a t Hig h an d Low Flo w Period s ........................ .

A-2 3 A- 7 Acreage s o f Ma p Unit s ............................. . A-3 0 A- 8 Classificatio n

o f Ma p Unit s fo r th e Residentia l Stud y Are a Soi l Inventor y ........................... . A-4 1 

### A- 9 Lan d Type s fo r th e Residentia l Stud y Are a Soi l Inventor y ........ . A-4 2 

### A-1 0 Physical an d Chemica l Analyse s o f Soi l Pedon s i n th e Residentia l Soil s Stud y Are a .......................... . A-4 4 A-1 1 Averag e Meta l Concentration s a t Forme r Smelte r Site s .......... .

A-5 1 

### A-1 2 Mea n Metal s Concentration s b y Dept h Interva l fo r < 2mm Soil s Dat a fo r Disturbe d an d Undisturbe d Sampl e Site s ................ .

A-5 4 

### A-1 3 Averag e Concentration s o f Pb
, Zn , As , an d C d fo r Area s Impacte d Predominantl y b y Smelte r Emission s ............... .

A-5 7 

### A-1 4 Surfac e Wate r Sample s - Parameter s Analyzed , Analytica l Method s an d Detectio n Limit s .............................. . A-6 1 

### A-1 5 Be d Material Sample s - Parameter s Analyzed , Analytica l Method s an d Detectio n Limit s .............................. . A-6 3 

### A-1 6 Procedure fo r Partitionin g a Singl e Populatio n Int o Tw o Normall y Distribute d Population s .................... .

A-7 3 A-1 7 Soil-Geologi c

Unit s and Correspondin g Dominan t Soi l Ma p Unit s ... . A-7 6 A-1 8 Estimate d Backgroun d Metal Concentration s fo r Uplan d an d Alluvia l Landscap e Position s ............................... . A-7 9 Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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### APPENDI X A TABL E O F CONTENT S (Continued ) LIS T O F TABLE S (Continued ) Tabl e No

. Titl

e Page A-1 9 Commo n Metal Range s i n Soil s o f the U.S

. ................ .

A-8 0 A-2 0 Estimate d Backgroun d Meta l Concentration s an d Dept h Weighte d Average s fo r Soil-Geologi c Unit s ................. .

A-8 1 A-2 1 Compariso n o f Soil Horizo n Averag e Metal Concentration s t o Backgroun d Concentration s ........................... .

A-8 2

Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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. epa\soils-ri\append-a.ju nAPPENDI X A TABL E O F CONTENT S (Continued ) LIS T O F ACRONYM S A S A America

n Societ y o f Agronom y CD H Colorad

o Department o f Healt h CD L Colorad

o Department o f La w CD M Cam p Dresse r & McKe e CE C Catio n Exchang e Capacit y CERCL A Comprehensiv e

Environmenta l Response
, Compensation
, an d Liabilit y Ac t 

### cf s cubi c fee t pe r secon d CL P Contract La b Progra m 

### c m centimete r CM C Colorad o Mountai n Colleg e CRDL s contrac t require d detectio n limit s EDXR X Energ y Dispersiv e X-Ra y Fluorescenc e E G Extende d

Gri d 

### EMP A electro n microprob e E P exposur e

poin t E- S Engineering-Scienc e 

### E W existin g privat e well s F degree

s fahrenhei t GFA A Graphit e Furnac e Atomi c Absorptio n GFAA S Graphit e Furnac e Atomi c Absorptio n Spectroscop y ( /min liters per minut e 

### m meter

s meq/ g milliequivalent

s pe r gra m mg/k g milligram s

pe r kilogra m mg/t milligrams

pe r lite r m m millimeter s mp h mile s pe r hou r MS L mea n se a leve l NAAQ S Nationa l Ambien t Ai r Qualit y Standar d 

### N P L Nationa l Prioritie s Lis t N W monitorin

g well s P G Primar

y Gri d PIX E Proton-Induce d

X-ra y Emission R I Remedia

l Investigatio n 

### RI/F S Remedia l Investigation/Feasibilit

y Stud y S A S specia l analytica l service s 

### S C S Soi l Conservatio n Servic e SE M scannin g electron microscop y S G Secondar

y Gri d Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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. epa\soils-ri\append-a.ju n

### LIS T O F ACRONYM S S R K Steffan
, Robertso n an d Kirste n 

### S T P Sanitar y Wastewate r Treatmen t Plan t T C L Targe t Compoun d Lis t 

### T S P total suspende d paniculat e micrograms/lite r microgram s pe r cubi c mete r micrometer s WESTO N Ro y F

. Weston , Inc

. USD A U.S

. Departmen t o f Agricultur e XR F X-Ra y Fluorescenc e

Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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. epa\soils-ri\append-a.ju nAPPENDI X A SOI L LEA D REMEDIA L INVESTIGATIO

N 

### Thi s sectio n describe s th e historical sit e characterizatio n dat a i n term s o f lea d contaminatio n h i th e environmenta l media : soils , ambien t air , an d surfac e water ; an d i n minin g derive d wastes

. A . 1 MAPPIN G 

### A t the reques t o f the U.S

. Environmenta l Protectio n Agenc y (EPA)
, a standard sit e bas e ma p 

### fo r th e Californi a Gulc h Nationa l Prioritie s Lis t (NPL ) Sit e was developed

. Thi s sit e bas e ma p
wa s develope d primaril y fro m electroni c ma p file s compile d b y IntraSearch
, Inc

. Th e IntraSearc h ma p file s wer e generated fro m aeria l photograph s o f th e site

. 

### Additiona l dat a source s wer e combine d wit h th e IntraSearch file s t o provid e th e location s an d othe r ma p feature s no t include d wit h th e Intrasearc h ma p fil e set

. Th e sit e bas e ma p identifie s 

### man-mad e transportatio n an d structura l feature s tha t include : roads , railroads , parkin g lots , airport , building s and histori c features

. Natura l hydrograph y feature s suc h a s strea m network s 

### an d othe r wate r bodie s ar e shown

. Topographi c feature s includ e 5-foo t elevatio n contour s an d spo t elevations

. Othe r feature s represente d o n thes e ma p product s includ e Remedia l Investigation/Feasibilit

y Stud y (RI/FS ) an d Residential Are a sit e boundarie s a s define d b y EPA

. Certai n contaminatio n source s suc h a s th e historica l location s o f smelter s an d mill s an d th e location s o f min e waste s 

### suc h a s sla g piles , wast e rock , an d tailin g impoundment s ar e identified

. Dat a o n tailin g impoundments , wast e roc k piles , an d sla g pile s wer e compile d b y Ro y F

. Weston , Inc

. (WESTON®)
, fro m Steffan
, Robertso n an d Kirste n (SRK ) (1989 ) an d Wals h an d Associate s 

### (1993)

. Location s o f fluvia l tailin g area s wer e compile d b y Woodward-Clyd e Consultant s (1993 )
an d smelte r location s b y ASARC O (1991)

. 

### Thes e ma p feature s wer e compile d b y IntraSearc h usin g photogrammetri c method s an d wer e ortho-rectified

. Th e groun d contro l surve y fo r th e photograph y wa s performe d b y Foresigh t Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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. epa\soils-ri\append-a.ju n

### Wes t Surveying
, Inc

. usin g extende d Nationa l Geodeti c Surve y horizonta l an d vertica l control

. Al l WESTO N ma p product s use d i n thi s repor t wer e develope d usin g thes e standar d bas e ma p elements , and wer e compile d usin g the "Colorad o Stat e Plan e Coordinat e System
, Centra l Zone "
an d Nationa l Mappin g Accurac y Standard s fo r 1:2,40 0 scal e maps

. Althoug h thes e ma p feature s cam e fro m th e divers e source s describe d an d wer e develope d usin g 

### variou s method s (electroni c digitizing , phot o ma p spotting , conventiona l surveying , etc.) , th e 

### geographi c positionin g o f thes e feature s i s base d o n th e commo n coordinat e syste m o f th e Colorad o Plane system

. A . 2 AI R PATHWA Y INVESTIGATIO

N (WCC

. 1992a ) 

### Thi s sectio n describe s the ambien t ai r monitorin g progra m and dat a develope d fo r the purpos e o f evaluatin g th e significanc e o f th e ai r rout e fo r migratio n o f lea d contaminant s i n th e Popukte d Stud y Area

. 

### A.2. 1 Objective s The purpos e o f the ambien t ai r monitorin g progra m (WCC
, 1992a ) wa s t o evaluat e the significanc e o f th e ai r pathwa y fo r th e migratio n o f contaminant s o f concern , suc h a s lead , t o 

### residentia l area s o f th e Californi a Gulch Site

. Seasona l meteorologica l condition s can caus e th e resuspensio n o f soil s an d min e waste s tha t ma y resul t i n th e generatio n o f airborn e particulat e contaminate d wit h lead

. Particulat e matte r wit h a aerodynami c diamete r o f ^ 1 0 micron s represent s a healt h concer n becaus e thes e particle s ca n b e inhale d an d deposite d i n th e lungs

. Thes e particle s ar e referre d t o a s th e PM-1 0 fraction

. A n ambien t ai r monitorin g program , conducte d durin g th e perio d o f 1 Octobe r 199 0 throug h 3 1 Octobe r 1991 , wa s designe d t o mee t 

### t h e followin g objectives :


### • Establis h baseline pollutan t levels

. 

### • Determin e th e impac t o f soi l particulat e emission s an d emission s fro m min e waste s o n th e environment

. Residential-Populate d

Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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. epa\soils-ri\append-a.ju n•

Provid e inhalabl e paniculat e (PM-10 ) ai r qualit y dat a fo r the ris k assessment

. 

### • Integrat e applicabl e dat a fro m othe r monitorin g programs

. A.2. 2 Method s 

### A.2.2. 1 Meteorologica l

Measurement s Th e meteorologica l dat a wer e collecte d a t th e 1 0 mete r meteorologica l tower s locate d a t th e CM C meteorological statio n locate d o n th e CM C campus , an d nea r th e Ya k Tunnel

. Th e dat a 

### collecte d covere d a 13-mont h perio d fro m 1 Octobe r 199 0 throug h 3 1 Octobe r 1991

. Th e meteorologica l parameter s recorde d wer e win d speed , win d direction , sigm a thet a (the standar d deviatio n o f th e horizonta l win d directio n fluctuations) , temperature , and relativ e humidity

. Sola r radiatio n an d precipitatio n wer e collecte d a t th e Ya k Tunne l station

. Hourl y Pasquill

- 

### Giffor d atmospheri c stabilit y classe s wer e compute d usin g value s o f sigma-thet a and win d spee d i n conjunctio n wit h th e tim e o f day

. Sno w cove r measuremen t dat a collecte d a t th e Leadvill e Airpor t wer e obtaine d fro m th e Colorad o Climat e Center
, Colorad o Stat e University , Ft

. Collins
, Colorado

. 

### A.2.2. 2 Ai r Qualit y Measurement s Th e ambien t ai r qualit y monitorin g dat a wer e collecte d a t fou r site s withi n th e Residentia l Soil s Stud y Area

. Dichotomou s sampler s fitte d wit h a PM-1 0 ai r intak e wer e use d t o collec t airborn e paniculate

. A t on e o f th e site s tw o sampler s wer e co-located fo r assessmen t o f instrumen t 

### precision

. T o obtai n backgroun d data , on e dichotomou s sample r wa s locate d a t th e Fis h 

### Hatchery , a sit e outsid e o f th e stud y area . Th e dichotomou s sample r filter s wer e analyzed fo r th e followin g ai r qualit y parameter s for whic h federa l an d stat e o f Colorad o ambien t ai r qualit y standard s exist: Respirabl e Paniculat e Mas s (PM-10 ) 

### Lea d

Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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. epa\soils-ri\append-a.ji mTh e PM-1 0 filte r wer e als o analyze d fo r th e followin g additiona l metals : Aluminu m Antimon y Arseni c Berylliu m 

### Cadmiu m Chromiu m Cobal t Coppe r Manganes e Mercur y 

### Nicke l Seleniu m Thalliu m 

### Vanadiu m Zin c A.2. 3 Result s A.2.3. 1 Meteorologica l

Condition s 

### Win d spee d an d win d directio n measure d a t th e CM C an d Ya k station s reflec t th e stron g influenc e th e comple x terrai n ha s o n thes e parameter s i n th e Leadvill e Region

. Th e Sawatch an d 

### Mosquit o mountai n range s hav e a majo r influenc e o n th e prevailin g wind s i n th e stud y area . Th e CM C win d ros e dat a fo r Octobe r 199 0 t o 199 1 presente d i n Figur e A- 1 sho w th e prevailin g wind s ar e fro m th e northwes t throug h th e nort h wit h a secon d maximu m occurrin g fro m th e east

northeast

. Th e Ya k statio n win d ros e dat a for th e sam e measuremen t perio d presente d i n Figur e 

### A- 2 sho w th e stronges t win d directio n t o b e westerl y wit h a secondar y maximu m fro m th e east

northeast

. Th e Ya k station' s win d directio n measurement s ar e strongl y influence d b y Carbonat e 

### Hil l topography

. 

### Th e meteorologica l dat a collecte d a t th e CM C sit e durin g th e 1 3 month s o f th e stud y indicat e tha t th e averag e monthl y win d spee d i s 5. 1 mph

. Th e minimu m monthl y averag e win d spee d


### o f 2. 0 mp h occur s durin g th e mont h o f October , an d th e maximu m averag e monthl y win d spee d
o f 7. 1 mp h occur s durin g th e mont h o f May

. Cal m condition s base d o n hourl y average s wer e Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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. epa\soils-ri\append-a.ju n<

n C M C M 

## s C M

C - SIT E ANNUA L (OC T 199 0 - OC T 1991 ) N N N W N N

E N E W N W E N E
W
W S W E S E S W S E S S W S S

E LEGEN

D 0. 0 - 4. 0 4. 0 - 7. 0 7. 0 - 12. 0 12. 0 - 18. 0 18. 0 - 24. 0 > 24. 0 MILE S / HOU R

NNWXR S DESOCB/CONStlTAW

S 21 5 Unio n Boulevar d Suit e 55 0 Lokewood

. C O 8022 8 (303 ) 980-680 0 U.S

. ENVIRONMENTA L PROTECTIO N AGENC Y CALIFORNI A GULCH
, LEADVILLE
, COLORAD O COLORAD O MOUNTAI N COLLEG E (CMC ) WIN D ROSE
, OCTOBE R 1990-199 1 FIGUR E

A- 1 Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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. epa\soils-ri\append-a.ju n

### Y A

K - SIT E ANNUA L (OC T 199 0 - OC T 1991 ) 

### N N N W N N

E N E W N W E N E
W
W S W E S E 

### S E



## ss w S S

E LEGEN

D 0. 0 - 4. 0 4. 0 - 7. 0 7. 0 - 12. 0 12. 0 - 18. 0 18. 0 - 24. 0 > 24. 0 MILE S / HOU R

WMUEX S 21 5

Unio n Boulevor d Suit e 55 0 I ® Lokewood
, C O 80228 (303 ) 980-680 0 U.S

. ENVIRONMENTA L PROTECTIO N AGENC Y CALIFORNI A GULCH
, LEADVILLE
, COLORAD O Y A K TUNNE L WIN D ROS E OCTOBE R 1990-199 1 FIGUR E



### A- 2 Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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. epa\soils-ri\append-a.ju n

### reporte d

durin g th e month s o f Octobe r an d November

. Th e maximu m hourl y averag e win d 

### spee d o f 20. 4 mp h wa s reporte d i n December

. Th e maximu m monthl y hourl y averag e win d spee d a t th e CM C statio n i s 15. 4 mph

. 

### Ther e i s a significan t seasona l variatio n i n win d directio n a t th e CM C station

. Win d directio n dat a fo r th e CM C statio n sho w a larg e variabl e i n win d directio n durin g th e perio d o f Marc h throug h October

. Th e win d directio n durin g th e sprin g an d summe r month s i s determine d t o 

### a larg e exten t b y convectiv e clou d formatio n an d associate d weathe r activity

. Durin g th e winte r month s o f Novembe r throug h February , win d directio n i s primaril y influence d b y large-scal e 

### weathe r system s an d b y th e passag e o f fronta l systems

. Th e meteorologica l dat a fro m th e Ya k statio n woul d sugges t ther e i s n o significan t seasona l 

### variation i n win d direction

. Thes e dat a ar e primaril y influence d b y th e topograph y an d i n particula r the locatio n o f the meteorological towe r i n clos e proximit y t o Carbonat e Hill

. The win d spee d an d win d directio n a s measure d b y thi s statio n ar e no t representativ e o f th e site' s 

### prevailin g winds

. A.2.3. 2 Ai r Qualit y Monitorin g PM-1 0 Samplers
, 1 A an d I B ar e co-located a t Harriso n Stree t an d Monro e Stree t i n Leadville

. Sample r 2 i s locate d a t 5t h Stree t an d Haze l Street

. Sample r 3 i s locate d a t th e Leadvill e Hig h 

### School

. Sample r 4 i s locate d a t th e Fis h Hatcher y an d represent s backgroun d condition s i n th e Leadvill e Region

. Al l dichotomou s filte r sample s wer e analyzed b y the Universit y o f Californi a a t Davis

. The analyse s wer e performe d usin g Proton-Induce d X-ra y Emission (PDO3)

. Al l 24-hou r dichotomou s sample r filter s wer e analyze d gravimetricall y fo r PM-1 0 paniculate

. Th e maximu m 24-hou r concentration o f PM-1 0 reporte d durin g th e 1-yea r stud y wa s 7 3 microgram s pe r cubi c 

### mete r (/ig/m 3 

### ) fo r th e 1 9 Marc h 199 1 samplin g period

. This valu e i s belo w th e 2 4 hou r PM-1 0 federa l standar d o f 15 0 /*g/m 3 

### (5 2 F R 105 , 1987)

. Residential-Populate d

Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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. epa\soils-ri\append-a.ju n

### Th e PM-1 0 filte r sample s wer e als o analyze d fo r contaminant s o f concer n tha t include d lead

. Th e mea n 24-hou r concentration s o f lea d foun d i n th e PM-1 0 fractio n ar e show n i n Tabl e A-1

. Th e quarterl y Nationa l Ambient Ai r Qualit y Standar d (NAAQS ) fo r lead , 1. 5 jig/m 3
, wa s no t 

### exceede d durin g th e stud y perio d a t an y o f th e PM-1 0 samplin g locations

. A . 3 POPULATE D STUD Y ARE A SURFACE SOI L INVESTIGATION

S Numerou s sit e characterizatio n studie s hav e bee n performe d a t th e Californi a Gulc h Sit e t o 

### develo p adequat e dat a t o evaluat e remedia l alternative s and complet e a feasibilit y study

. A


### summar y o f th e objective s o f thes e sit e investigation s include s th e characterizatio n o f soils ; th e 

### identificatio n o f area s tha t hav e bee n impacte d b y historica l smelte r emissions ; th e speciatio n o f lea d an d other metal s o f concer n i n soil s an d min e waste ; an d th e distributio n o f lea d i n surficia l soil s locate d i n the Populate d Stud y Area

. The specifi c studies tha t wer e conducte d t o characterize th e Populate d Stud y Are a withi n th e Californi a Gulc h Sit e ar e summarize d below

. 

### A.3. 1 Stat e o f Colorad o Department o f La w (E-S

. 1986 ) I n Octobe r 198 6 the Colorad o Departmen t o f La w (CDL ) conducte d a soil s investigatio n o f the residentia l an d commercia l land s withi n th e cit y o f Leadvill e an d th e communit y o f Stringtown

. 

### Th e soi l samplin g stud y desig n wa s base d o n earlie r ai r qualit y studie s conducte d b y 

### Engineering-Scienc e (E-S ) (E-S
, 1986 ) an d ai r modelin g o f th e Leadvill e regio n b y Bigg s (E-S
, 1986)

. Th e objective s o f th e stud y were :


### • T o collec t an d analyz e surface , surfac e t o 2 inches , an d near-surfac e ( 2 t o 6 inches ) soi l sample s fro m residentia l areas . • T o determin e th e natur e an d geographi c exten t o f meta l contaminant s withi n th e stud y area . 

### • T o defin e potentia l sources , pathways , an d meta l receptor s i n residentia l an d commercia l soils

.

Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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. epa\soils-ri\append-a.ju n

### Tabl e A- l PM-1 0 Lea d Mea n Concentration s

Elemen t Lea d Mea n PM-1 0 Concentration s (/ig/m 3 ) a t Dichotomou s Sample r Station s 1 A 0.03 6 I

B 0.034 6 2 0.056 6 3 0.037 7 4 0.012 4 Source : WCC
, 1992 a jig/m * = microgram s pe r cubi c mete r

Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Documen t Contro l No

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. epa\soils-ri\append-a.ju n Jun e 1996 PageA- 9 I T SHAL L NO T B E RELEASE D O R DISCLOSE D I NTh e nativ e soil s i n th e Leadvill e and Stringtow n stud y are a consis t primaril y o f deep , well

draine d material s tha t ar e forme d i n ston y an d cobbly , medium-texture d glacia l outwash

. Th e 

### primar y soil s i n th e stud y are a occu r i n th e Troutville-Leadvill e association

. Th e stud y are a t o 

### b e sample d wa s divide d int o thre e quadrants , identifie d a s Area s 1,2 , an d 3

. Area s 1 an d 3


### wer e separate d fro m Are a 2 b y Harriso n Street

. Area s 1 an d 3 wer e separate d b y Eas t 8t h Street

. Are a 2 i s locate d b y sout h o f Wes t 8t h Street

. Contro l sample s wer e take n fro m a n are a northwes t o f Leadville

. Th e soil s sample d wer e fro m th e Leadvill e sand y loa m and Pieria n gravell y sand y loam

. Th e majorit y o f th e soil s sample d wer e slightl y t o moderatel y moist , 

### indicatin g moderat e permeabilit y an d wate r capacity

. Soi l p H range d fro m moderatel y acid , 5.6 , t o neutral , an d t o slightl y basic , 7.3 , i n th e surfac e layers

. A.3.1. 1 Soi l Samplin g 

### Durin g th e soi l survey , 16 8 surfac e soi l samples wer e collected

. Thes e sample s include d 14 0 sample s tha t wer e collecte d fro m 8 2 block s withi n th e cit y limit s o f Leadville

. Leadvill e wa s divide d int o fou r quadrants , an d sample s wer e take n fro m th e northeastern , southeastern , an d 

### southwester n portion s o f Leadville

. Th e northwester n quadran t wa s no t sample d becaus e i t wa s 

### no t withi n th e Californi a Gulc h drainage

. I n addition , 1 7 surfac e soi l sample s wer e collecte d fro m 1 0 location s i n Stringtown

. Subsurfac e soi l sample s wer e collecte d fro m 4 7 location s 

### wher e surfac e sample s wer e als o taken

. I n orde r t o compare metal s concentratio n i n soil s sample d fro m heavy-us e area s i n Leadvill e an d Stringtow n wit h light-us e areas , nin e vacan t lot s locate d adjacen t t o sample d residentia l propertie s wer e identifie d fo r sampling

. Heavy-us e area s 

### ar e define d a s residentia l properties , an d vacan t lot s ar e define d a s light-us e areas . A rando m numbe r generato r wa s use d t o locat e th e exac t samplin g sit e wher e soi l sample s wer e t o b e collected

. Soi l samples wer e no t take n fro m garde n areas , coa l as h deposi t areas , o r area s nea r street s an d alleys

. 

### Contro l area s wer e identifie d outsid e o f th e stud y are a tha t wer e considere d t o b e undisturbe d b y historica l minin g activities

. Thes e samples wer e use d for baselin e characterizatio n o f th e stud y area . I n selectin g thes e contro l areas , consideratio n wa s give n t o win d patterns , soi l types , Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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. epa\soils-ri\append-a.ju n

### topography ,

lan d use , an d drainag e patterns

. Th e contro l area s wer e selecte d withi n th e Leadvill e serie s soils , an d th e location s wer e believed t o b e upwind o f curren t an d pas t emissio n 

### sources . Soi l sample s wer e take n fro m thes e contro l areas , an d th e samplin g location s wer e selecte d base d o n randoml y generated numbers

. A.3.1. 2 Soi l Samplin g Metho d 

### Soi l sample s wer e collecte d usin g a 3.75-inc h stainless-stee l bucke t auger . Eac h soi l sampl e wa s a composit e o f thre e subsample s collecte d withi n a 5-foo t radiu s o f th e sampl e point , an d a t equa l radia l an d angula r distances

. Al l samplin g equipmen t wa s decontaminate d betwee n soi l dept h samplin g an d betwee n subsampl e location s a t eac h samplin g point

. 

### A.3.1. 3 Chemica l Analysi s Surfac e and subsurfac e soi l samples wer e analyzed fo r concentration s o f lead , cadmium , arsenic , an d nicke l b y inductively-couple d plasma-atomi c emissio n spectroscopy

. A.3.1. 4 Soi l Surve y Result s 

### Soil s throughou t Leadvill e an d Stringtow n exhibi t varyin g concentration s o f lead

. O n average , soi l sample s fro m Leadvill e hav e lea d concentration s tw o t o fiv e time s highe r tha n thos e i n th e contro l area . Th e margi n o f differenc e fo r lea d concentration s i n Stringtow n soil s compare d t o contro l are a soil s wa s eve n higher tha n tha t o f Leadville

. Th e concentration range s an d 

### geometri c mea n concentration s o f lea d foun d withi n th e stud y are a an d contro l are a samples ar e summarize d i n Tabl e A-2

. Th e highes t mea n concentration s o f lea d i n soi l wer e fro m samples collecte d i n th e southeas t an d southwest quadrant s o f Leadville

. Thes e area s o f Leadvill e ar e neares t t o th e tailing s pond s an d wast e piles

. Thes e result s ar e supporte d b y th e dat a obtaine d i n th e ai r qualit y modelin g studie s o f th e Leadvill e regio n performe d b y Bigg s i n 1986

.

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. epa\soils-ri\append-a.ju n

### Tabl e A- 2 Soi l Lea d Concentration s i n Stud y Area s o f Leadville
, Stringtown
, an d Contro l Are a Samplin g Are a Are a 1 Surfac e Subsurfac e Are a 2 Surfac e Subsurfac e Area S Surfac e Subsurfac e Control Are a Surfac e Subsurfac e Lea

d Concentratio n (mg/kg ) Rang e
28 0 - 7,00 0 25 0 - 12,00 0

110 - 9,00 0 15 0 - 8,00 0

30 0 - 2,60 0 91 0 - 3,50 0

24 0 - 2,60 0 36-50 0 Geometri

c Mea n
2,53 8 2,24 0
1,14 4 1,20 1
1,28 3 1,51 5

82 2 8 9 mg/k g = milligram s pe r kilogra m

Residential-Populate d

Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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. epa\soils-ri\append-a.ju n

### Surfac e

soi l lea d concentration s i n eigh t o f th e nin e vacan t lo t sample s excee d th e lea d concentration s foun d i n surfac e soi l samples take n fro m adjacen t residential properties

. However , thi s differenc e wa s foun d t o b e statisticall y insignificant

. Th e highes t surfac e soi l lea d concentration i n Leadvill e o f 9,00 0 mg/k g wa s 1 1 time s higher tha n th e geometri c mea n concentratio n fo r surfac e soil s i n th e contro l area . Th e highes t 

### subsurfac e lea d concentratio n o f 12,00 0 mg/k g wa s mor e tha n 1 7 time s highe r tha n th e maximu m averag e lea d concentratio n i n soil s o f mineralize d area s o f th e wester n Unite d State s 

### (E-S
, 1986)

. Averag e lea d concentration s i n Stringtow n soil s wer e 2 an d 1 7 time s highe r tha n th e lea d concentration s i n contro l sit e surfac e an d subsurfac e soils , respectively

. Th e highes t concentration s o f lea d wer e foun d i n th e easter n sectio n o f Stringtow n wher e sla g pile s an d tailing s impoundment s wer e present

. T o determin e th e effect s o f distanc e fro m emissio n source s o n lea d concentrations , th e Leadvill e 

### portio n o f th e stud y wa s subdivide d radially , an d soi l sampl e point s wer e separate d int o group s representin g distance s withi n 1,00 0 feet , withi n 2,60 0 feet , and beyon d 2,60 0 fee t o f the tailing s an d wast e pile s i n Californi a an d Stra y Hors e Gulches

. Figur e A- 3 portrays th e thre e soi l 

### sampl e group s a s a functio n o f radia l distanc e fro m th e emission source s represente d b y th e tailing s an d wast e pile s i n Californi a an d Stra y Hors e Gulches

. The dat a indicat e a stead y declin e i n surfac e soi l lea d concentration s t o th e wes t an d northwest i n Leadville

. Th e surfac e geometri c mea n concentratio n fo r lea d i n soil s withi n 1,00 0 fee t o f th e wast e source s i s 

### 2,95 4 mg/kg

. Thi s concentratio n i s nearl y twic e th e concentration o f lea d i n th e grou p o f soi l sample s obtaine d betwee n 1,00 0 fee t an d 2,60 0 fee t o f th e min e wastes

. Th e CD L soi l surve y indicates tha t a n anomal y i n lea d concentratio n exist s i n a grou p o f soi l samples take n fro m nea r th e corne r o f Eas t 7t h Stree t an d Hemloc k i n Leadville

. Thi s locatio n i s incorrect

. Thi s anomal y i s attribute d t o th e Coronad o Shaf t an d th e railroa d spur junctions

. A lea d 

### concentratio n anomal y o f 12,00 0 mg/k g exist s a t soi l sampl e locatio n 1-21 B an d i s locate d nea r th e Coronad o wast e pil e i n eas t Leadvill e an d nort h o f 7t h Street

.

Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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. epa\soils-ri\append-a.ju n4601026.CW-02229 4

T )



## I 

# I

1 1 80 0 meter s 

### FIGUR E A- 3 

## RADIA L GROUP S OF SOI L SAMPL E LOCATION S A S A FUNCTIO N O F DISTANC E FRO M EMISSION S SOURCE S
I 

## CONTRO L

ARE AA.3. 2

Remedia

l Investigatio n Repor t (CHJ M Hill

. 1987 ) Th e objectiv e o f th e Phas e I Remedia l Investigatio n (RI ) Repor t fo r th e Californi a Gulc h Sit e 

### wa s t o characterize th e sit e an d summariz e th e dat a collecte d durin g th e Phas e I investigations

. Th e sit e characterizatio n include s identifyin g contaminant s i n surfac e wate r withi n th e sit e drainag e area ; th e natur e an d exten t o f groundwate r contaminatio n alon g th e Californi a Gulch ; 

### an d source s o f meta l contaminatio n withi n th e sit e drainage basi n an d thei r relativ e contribution s t o wate r qualit y degradatio n i n th e Arkansa s Rive r a t th e confluenc e wit h Californi a Gulch

. Th e R I Repor t identifie d ove r 2,000 wast e dump s tha t rang e i n siz e fro m a fe w ton s t o ove r 

### 100,00 0 tons

. Thes e ar e locate d nea r min e shaft s o r portal s i n th e uppe r Californi a Gulch
, Carbonat e Hill , Stringtown
, an d Stra y Hors e Gulch

. Som e o f th e pile s i n th e Stra y Hors e Gulc h


### ar e nea r residentia l area s withi n th e Populate d Stud y Area

. Sla g pil e location s wer e identifie d 

### i n Leadvill e o n Harriso n Stree t an d i n Stringtown

. A.3.2. 1 Geolog y Withi n thi s report , th e bedroc k geolog y o f th e Leadvill e Minin g District i s describe d a s 

### consistin g o f Precambria n crystallin e rock s overlai n b y quartzites , shales , limestones , dolomites , an d sandstones o f Paleozoi c age . Several type s o f surficia l deposit s wer e identifie d an d includ e 

### talu s debris , landslid e deposits , an d roc k glaciers

. Glacial
, glaciofluvial , an d alluvial deposit s wer e identifie d a t lowe r elevation s i n th e area . Thes e deposit s wer e disturbe d b y place r gol d minin g activitie s durin g th e 1800s

. Numerou s fault s exis t withi n th e minin g district

. Tw o o f 

### thes e faults , th e Valentin e Faul t an d th e Pender y Fault , ar e locate d withi n th e Populate d Stud y Area

. 

### Th e mos t prominen t or e mineral s tha t ar e presen t i n th e Leadvill e Minin g District ar e presente d i n Tabl e A-3

.

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### Tabl e A- 3 Mos t Prominen t Mineral s o f th e Or e Deposit s o f th e Leadvill e Minin g District Minera l Arsenopyrit e Barit e Calcit e Cerussit e Chalcanthit e Chlorit e (Clinochlore ) Dolomit e Galen a Gol d Hematit e Jarosit e Limonit e Manganosiderit e Melanterit e Pyrit e Pyrolusit e Pyromorphit e Quart z Sericit e Siderit e Silve r Smithsonit e Specularit e Sphalerit e Chemica l Formul a FeAs S o r FeS 2 • FeAs j BaSO 4 CaCO 3 PbCO 3 CuSO 4 • 5H 2 O H 4 M g 3 S i 2 O 9 • H<Mg 2 A l 2 SiO 9 CaM g (C0 3 ) 2 Pb S A u F e A KFejCSO^OH ^ Fe(OH) 3 (Fe , Mn , Mg ) CO 3 FeSO 4 -7H 2 O FeS 2 MnO 2 Pb 5 (P0 4 ) 3 C l SiO 2 K H 2 A l 3 (SiO 4 ) 3 FeCO 3 A g ZnCO 3 F e A Zn S Source : Emmon s e t al. , 192 7 a s cited i n Jacob s Engineerin g Group
, Inc. , 1991

.

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. epa\soils-ri\append-a.ju nA.3.2. 2

Soil s 

### Th e predominant soil s associate d wit h th e Californi a Gulch Sit e an d th e Populate d Stud y Are a ar e classifie d a s Bross
, Leadville
, Pierian
, an d Troutvill e series

. N o backgroun d informatio n i s availabl e concernin g th e geochemistr y o f sit e soil s prio r t o minin g activities

. Placer an d hydrauli c gol d minin g and earl y millin g operation s resulte d i n significan t alteratio n o f surfac e 

### material s an d structur e i n th e Populate d Stud y Are a an d th e Californi a Gulc h Site

. Placer an d 

### hydrauli c minin g create d mixe d an d rewor k alluvium s an d altere d natura l stream-bed s an d floo d plains

. Uncontrolle d min e wast e fro m histori c or e millin g operation s i n th e Uppe r Californi a Gulc h hav e adde d sediment s t o th e lowe r Gulch

. A.3.2. 3 Surfac e Wate r Th e Californi a Gulc h drain s approximatel y 7,40 0 acre s o f watershe d int o th e Arkansa s River

. 

### The mainste m o f the Gulc h receive s wate r fro m severa l ephemera l drainage s tha t includ e the Star r Gulch
, th e uppe r Californi a Gulch
, th e Orego n Gulch
, th e Pawne e Gulch
, th e Airpor t 

### Gulch
, an d th e Malt a Gulch

. Th e averag e flo w a t th e confluenc e o f th e Californi a Gulc h wit h 

### th e Arkansa s Rive r range s fro m 2. 2 t o 6. 4 cubi c fee t pe r secon d (cfs)

. Durin g rapi d snowmel t i n th e spring , floodin g i n th e are a ma y occur . Th e floo d potentia l i n th e uppe r Gulc h i s quit e hig h becaus e o f the relativel y spars e vegetation

. The Cor p o f Engineers 

### estimat e o f th e 100-yea r floo d even t indicate s tha t th e are a wher e th e Californi a Gulch crosse s U.S

. Rout e 2 4 woul d b e impacte d b y th e event

. 

### A.3.2. 4 Climat e 

### Weathe r condition s ar e recorde d at the Nationa l Weathe r Service' s Leadvill e airpor t meteorologica l statio n locate d 2 mile s southwes t o f Leadville

. The norma l temperatur e extreme s rang e fro m a hig h o f 86 F t o a minimu m o f -30 F

. Th e averag e minimu m temperatur e bein g 21.9 F

. Residential-Populate d

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### Th e averag e annua l precipitatio n i s 17.5 3 inche s wit h maximu m precipitatio n occurrin g durin g th e month s o f Jul y an d August

. Month s i n whic h th e lowes t amount s o f precipitatio n occurre d


### ar e Decembe r an d January

. Summertim e precipitatio n i s associate d wit h th e occurrenc e o f rai n showers

. 

### The annua l snowfal l depth s fo r the mountain s i n the regio n outsid e o f the stud y are a rang e fro m 7 9 t o 20 3 inches

. Thi s snowfal l occur s withi n th e watershed tha t impact s th e Populate d Stud y Area

. Durin g th e winte r month s th e averag e sno w dept h o n th e groun d i n Leadvill e i s 6 inches

. 

### The runof f fro m the snowmel t reache s a pea k i n the mont h o f June

. A.3.2. 5 Ai r Qualit y 

### Limite d ai r qualit y dat a wer e availabl e fo r the Leadvill e are a fro m the Colorad o Departmen t o f Healt h (CDH)

. CD H ha s operate d high-volum e ai r sampler s i n Leadvill e fo r measuremen t o f 

### tota l suspende d paniculat e (TSP ) an d lead

. A.3.2. 6 Natur e an d Exten t o f Contaminatio n
Th e remnant s o f minin g relate d activitie s suc h a s min e wast e dumps , sla g piles , soils , an d sediment s ar e potentia l source s o f meta l contaminatio n t o surfac e wate r an d soils

. Th e mine d


### ore s wer e processe d i n th e millin g operatio n t o produc e silver , lead , an d zin c concentrates

. Th e ore millin g produce d tailing s tha t containe d pyrite

. Th e oxidatio n o f pyrit e presen t i n min e waste s result s i n th e mobilizatio n o f metal s an d th e productio n o f sulfuri c aci d tha t acidifie s 

### surfac e waters

. Thi s proces s als o result s i n producin g compound s (oxidatio n state s o f som e metals ) tha t ma y b e mor e solubl e i n surfac e water s o r th e proces s merel y release s the m fro m a n 

### immobil e matri x an d produce s a mobil e materia l tha t coul d b e transporte d b y wate r erosio n o r win d erosion

.
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. epa\soils-ri\append-a.ju nTh e tailing s fro m th e millin g operatio n are chemicall y heterogeneou s sinc e th e ore s mine d varie d i n thei r compositio n ove r time

. This mad e th e tailin g difficul t t o sampl e i n orde r t o obtai n 

### representativ e sample s fo r analyse s t o determine the chemica l constituent s makin g u p the tailings

. Th e tailing s characterizatio n goa l wa s t o asses s i f an y o f th e tailing s impoundment s containe d a potentia l sourc e o f metal s tha t wer e foun d i n nearb y surfac e wate r an d groundwater

. Sample s wer e collecte d fro m th e tailing s impoundment s wit h th e use o f a n auger . Th e auge r wa s use d t o sampl e t o a dept h o f approximatel y 7 feet

. 

### Th e majo r facto r affectin g th e potentia l failur e o f th e impoundment s appear s t o b e embankmen t erosio n fro m surfac e wate r runoff

. Thes e impoundment s ca n ac t a s source s o f heav y metal s t o 

### surfac e water

. Strea m Sediment s 

### Ther e i s a seasona l variatio n i n surfac e wate r flo w withi n the Californi a Gulch

. The strea m flo w i s generall y controlle d b y th e discharg e fro m th e Ya k Tunne l an d th e Sanitar y Wastewate r Treatmen t Plant

. Durin g snowmel t an d heav y rainstorms , th e ephemera l drainage s suc h a s th e Orego n Gulch
, Star r Ditch
, an d th e uppe r Californi a Gulch contribut e significantl y t o th e amount s o f additiona l flow

. Th e additiona l flo w durin g pea k runof f period s increase s strea m velocit y an d potentia l fo r erosion

. Thi s ca n resul t i n th e resuspensio n an d transpor t o f significan t quantitie s o f sediments

. Th e delt a nea r th e confluenc e o f th e Gulc h an d th e Arkansa s 

### Rive r i s a n exampl e o f th e sedimentatio n process

. Durin g th e constructio n o f th e flum e a t locatio n SW-12
, tw o soil/sedimen t samples wer e take n fo r characterization

. Th e samples wer e 

### collecte d a t th e surfac e an d a t a dept h o f 4 feet

. Th e soil/sedimen t samples wer e analyzed , an d th e metal s concentration s are presente d i n Tabl e A-4

. Th e soil/sedimen t meta l concentration s 

### wer e compare d t o th e concentration s o f thes e metal s i n tailings

. Thi s compariso n showe d tha t th e soil/sedimen t had : simila r iro n concentrations ; highe r lea d concentrations ; an d lowe r 

### cadmium , zinc , an d manganese concentrations

. Th e surfac e soil/sedimen t sampl e had highe r concentration s o f cadmium, copper , iron , lead , manganese, zinc , arsenic , mercury , an d silve r 

### tha n th e subsurfac e sample

. The soil/sedimen t samples wer e subjec t t o th e EP-Toxicit y test , an d 

### th e surfac e sampl e exceede d th e criteri a fo r lead

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. epa\soils-ri\append-a.ju n

### Tabl e A- 4 Soil/Sedimen t Sample s

Paramete r Aluminum , A l Chromium
, tota l C r Barium
, B a Beryllium
, B e Cadmium
, C d Cobalt
, C o Copper
, C u Iron , tota l F e Lead
, P b Nickel , N i Manganese , M n Zinc , Z n Boron
, B Vanadium , V Calcium
, C a Magnesium , M g Sodium
, N a Potassium
, K Arsenic , A s Antimony , S b Selenium
, S e Thallium , T l Mercury , H g Tin , S n Silver
, A g Cyanide
, tota l C N Sulfur
, tota l S P H Moistur e Sulfat e (SO 4) , Solubl e Chloride
, C l SW-1 2

Soi l (Surface' ) AsRec' d (nig/kef ) 1,68 0 3.5 5 15 4 <0. 2 9.8 9 2.1 7 52. 6 13,60 0 1,79 0 2.3 7 1,03 0 1,55 0 3 9 3. 9 45 6 26 6 26. 4 18 5 18. 4 <1 0 <1.1 0 < 2 4.2 1 <2 0 5.7 3 <0.0 2 2,26 0 3.9 125,00 0 6,58 0 69 6 SW-1 2 Soil/Cla y Dr y (ma/kg ) 1,92 0 4.0 5 17 6 <0. 2 11. 3 2.4 8 60. 2 15,50 0 2,04 0 2.7 1 1,18 0 1,77 0 4 4 4. 4 52 1 30 4 30. 2 21 1 21. 0 <1 1 <1.1 0 < 2 4.8 1 <2 3 6.5 5 <0.0 2

—

—

—

—

— (a

t AsRec' d (mg/kg ) 9,59 0 20. 9 78. 3 1.2 6 0.08 8 4.9 2 8.0 8 6,55 0 15. 9 8.21 45 4 351 12. 6 26. 5 2,31 0 2,64 0 15. 1 25 8 4.17 6. 3 0.10 5 < 1 0.66 0 <1 3 0.1 3 <0.0 2 1,20 0 5. 0 318,00 0 2,62 0 2,68 0 Depth ) Dr y (ma/ka ) 140,00 0 30. 6 11 5 1.8 5 0.12 9 7.2 1 11. 8 9,60 0 23. 3 12. 0 66 5 51 4 18. 5 38. 8 3,39 0 3,87 0 22. 1 37 8 6.1 1 9. 2 0.1 5 < 2 0.96 7 <1 9 0.1 9 <0.0 2

—

—

—

—

— mg/k g milligram s

pe r kilogra m

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. epa\soils-ri\append-a.ju nSlag s Fiel d investigation s o f the sla g pile s wer e not performe d a t the Californi a Gulc h sit e durin g thi s investigation

. 

### Surfac e Wate r Surfac e wate r act s a s th e primar y transpor t mechanis m for bot h solubl e metal s an d metal-lade n sediments

. Th e principa l contributor s t o surfac e flo w i n th e mainste m o f th e Gulc h are th e 

### discharge s fro m th e Ya k Tunne l an d th e Sanitar y Wastewate r Treatmen t Plan t (STP)

. Flo w fro m the Ya k Tunne l varie s seasonall y betwee n 1 and 2 cfs , and the flo w fro m the ST P i s a t a nearl y constan t rat e o f 1 cfs

. Surfac e wate r sample s wer e collecte d durin g fiv e quarterl y samplin g period s a t flum e location s 

### startin g wit h th e Ya k Tunne l an d endin g a t th e Arkansa s River

. Surfac e wate r sample s wer e als o collecte d durin g time s o f hig h flo w rate s an d lo w flo w rates

. Thes e wate r sample s wer e analyze d fo r p H an d dissolve d an d total metals

. The pH s at lo w flow s wer e consistentl y highe r tha n thos e observe d a t hig h flow s fo r th e sam e flum e samplin g locations

. Th e concentration s o f dissolve d metals , measure d i n sample s take n durin g a hig h flo w period , wer e highe r tha n th e 

### concentration s o f th e sam e metal s foun d i n samples tha t wer e take n durin g lo w strea m flow

. Th e p H an d metal s dat a fo r lo w an d hig h flo w period s ar e summarize d i n Table s A- 5 an d A-6 , respectively

. Dissolve d cadmium , zinc , an d sulfat e concentration s durin g low an d hig h Gulc h flow s ar e presente d i n profil e i n Figur e A-4

. Thi s figur e identifie s ke y surfac e wate r flo w locations an d potentia l contributor s o f contaminants

. Beginnin g wit h samplin g locatio n SW- 1 

### i n th e uppe r Californi a Gulc h th e metal s concentration s ar e relativel y low

. A s a resul t o f th e Ya k Tunne l discharg e ther e i s observe d a rapi d increas e i n metal s concentrations

. Th e metal s concentratio n continu e t o increas e a t samplin g locatio n SW-4

. This contributio n o f metal s i s 

### comin g fro m th e tailing s impoundments

. Ther e appear s t o b e a n anomal y i n th e cadmiu m concentratio n reporte d fo r SW- 4 durin g hig h flow

. Th e expecte d concentratio n woul d b e muc h highe r tha n tha t reporte d fo r hig h flo w conditions

. Th e concentratio n o f metal s continue d t o Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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. epa\soils-ri\append-a.ju n

### Tabl e A- 5 Surfac e Wate r Flo w Rate s an d p H Californi a Gulch-Arkansa s Rive r A t Hig h an d Lo w Flo w Period s
Locatio n Descriptio n Statio n

Nam e Hig h

Flo w Jun e 198 5 Flo w (eft ) p H

(s.u. ) Lo w

Flo w Novembe r 198 4 Flo w (eft ) P

H (s.u. ) Californi a Gulc h Mainste m Uppe r Ca t Gulc h Millyar d Flum e Tailing s Are a Belo w Apach e Middl e Flum e Stringtow n SW- 1

SW- 2 SW- 3 SW-3 A SW- 4 SW-4 A 2.6

7 Dr y 2.7 0 3.5 2 6.1 5 N A 3. 4

N A 3. 2 3. 2 3.2 N A 0.3

1 0.1 5 1.1 0 1.5 7 0.8 9 N A 8. 1

7. 6 6. 0 6. 0 3. 7 N A Tributarie s Parkvill e Lea k Y a k Tunne l Stai r Ditc h Orego n Gulc h Berthod Sprin g Stor m Drai n Georgia Gulc h Supe r 8 Sprin g Pawne e Gulc h Airpor t Gulc h Sla g Pil e Sprin g S T P Malt a Gulc h SW- 5

SWI- 1 SW- 6 SW- 7 SWI- 2 SWI- 3 SW- 8 SWI- 4 SW- 9 SWI- 5 SW-1 0 SW-1 1 SWI- 6 0.3

5 0.0 4 0.0 8 3.8 8 Dr y 0.0 3 1.0 2 Dr y 5.7 6 Dr y 0.0 3 0.9 3 Dr y 3. 3

2. 8 4. 1 3. 2 N A 6. 6 7. 1 N A 3. 3 N A 6. 6 7. 4 N A 0.5

8 Dr y Dr y 2.5 3 Dr y 0.0 3 0.0 1 Dr y 2.3 8 Dr y 0.1 1 1.1 3 Dr y 7. 6

N A N A 6. 3 N A 6. 8 7. 5 N A 5. 5 N A 6. 3 8. 3 N A Confluenc e Lowe r Flum e Uppe r Arkansa s Rive r Lowe r Arkansas Rive r SW-1 2 SW-1 3 SW-1 4 3.8

5 30 0 N A 4. 0

7. 4 7. 1 1.5

2 3 0 N A 7. 0

8. 8 8. 5 cf s = cubi c fee t pe r secon d N A = No t available/no t analyze d S.U

. = standar d p H unit s
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. epa\soils-ri\append-a.ju n

### Tabl e A- 6 Metal Concentration s 

### Californi a Gulch - Arkansa s Rive r a t Hig h an d Lo w Flo w Period s

Paramete r Aluminu m (Al ) Cadmiu m (Cd ) Calciu m (Ca ) Coppe r (Cu ) Iro n (Fe ) Magnesiu m (Mg ) Manganes e (Mn ) Zin c (Zn ) HIG H FLO W (Jun e 1985 ) Lowe r en d o f Ca l Gulc h (SW-12 ) Dissolve d fog/* ) 3,92 0 27 7 101,000 2,50 0 4,11 0 50,20 0 18,40 0 55,60 0 Tota l fog/ O 5,14 0 28 2 109,00 0 2,56 0 16,90 0 50,00 0 19,50 0 57,70 0 Ar k Rive r abov e Conf l (SW-13 ) Dissolve d (Atg/ 0 2 6 U 9,95 0 4. 9 8 3 3,96 0 4 0 10 9 Tota l 0<g/ 0 14 4 U 10,500 4. 0 32 4 3,98 0 5 8 13 2 Ar k Rive r belo w Conf l (SW-14 ) Dissolve d 

## w> 4 9 7. 3 11,50 0 2 1 8 8 4,73 0 21 8 59 4 Tota l G*g/ 0 35 5 4. 0 12,20 0 2 9 66 4 4,73 0 25 3 70 9

Paramete r Aluminu m (Al ) Cadmiu m (Cd ) Calciu m (Ca ) Coppe r (Cu ) Iro n (Fe ) Magnesiu m (Mg ) Manganes e (Mn ) Zin c (Zn ) LO W FLO W (Novembe r 1984 ) Lower en d o f Ca l Gulc h (SW-12 ) Dissolve d (IVft) U 4 7 66,51 0 1 3 5 6 33,53 0 9,07 4 14,71 0 Tota l fog/ O 36 8 6 2 67,27 0 2 6 1,09 2 32,02 0 9,22 2 20,17 0 Ar k Rive r abov e Conf l (SW-13 ) Dissolve d fog/ 0 8 1 U 23,03 0 U 10 1 8,45 0 10 3 24 0 Tota l fog/ 0 26 5 U 17,60 0 1 2 61 9 7,03 9 14 5 33 1 Ar k Rive r belo w Conf l (SW-14 ) Dissolve d (Ml*) U U 28,16 0 U 3 8 11,860 64 9 1,31 7 Tota l fog/ 0 41 9 U 28,38 0 U 45 9 11,12 0 65 7 1,62 5 U = Undetecte d a t detectio n limits

. pgll = microgram s pe r lite r
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. epa\soils-ri\append-a.ju n4601023.CW-02229 4 

## I s : f g 1 s


# i s 2



# ii» R

w *!

> s i 400- |

300

- 200

- 100

- 0

- 90- i 80

- 70

- 60

-

-= - 50

- 40

- 30

- 20

- 10

- 0

- DISSOLVE

D C d (6/85 )

160 0

^120 0

-80 0

-40 0 

# I

SW-1 2 SW-1 1 SW- 9 SW- 7 SW- 4 SW-3 A SW- 1 HIG H FLO W LO W FLO W

KSOOS/CONSUltAW S 2 1 5 Unio n Goulevor d Suit e 55 0 Lakewood

. C O 8022 8 (303 ) 980-680 0 EP

A CALIFORNI A GULC H LEADVILLE
, COLORAD O SURFAC E WATE R PARAMETE R VARIANC E ALON G CALIFORNI A GULCH FIGUR E



### A- 4

### remai

n hig h throug h samplin g statio n SW-8

. Fro m SW- 9 t o SW-1 2 th e marke d decrease i n metal s concentration s i s du e t o th e effec t o f dilutio n b y th e discharg e fro m th e STP

. Th e p H

o f th e surfac e wate r wa s also observe d t o increas e unde r bot h lo w an d hig h flo w condition s afte r 

### samplin g locatio n SW- 9 a s show n b y Tabl e A-5

. This i s du e t o the hig h alkalinit y o f the ST P discharge

. Durin g th e hig h flo w condition s th e observe d increas e i n metal s concentration s i s probabl y associate d wit h th e entrainmen t o f sediments

. Potentia l source s o f heav y metal s contaminant s includ e th e Ya k Tunne l (SW-3)
, th e Star r Ditc h (SW-5)
, an d th e Stringtow n are a (abov e SW-9)

. Star r Ditc h contribute s metal s tha t ar e probabl y originatin g fro m min e waste s locate d o n the nort h sid e o f Carbonat e Hil l and Stra y Hors e Gulc h and includ e Hamm s Mil l 

### Tailing s an d Penros e Wast e Pile

. Th e consistentl y hig h level s o f metal s an d sulfate s at SW- 9
ma y b e originatin g fro m nearb y sla g piles

. A.3. 3 Soil Investigation s i n the Leadvill e Stud y Are a (Walsb

. 1988 ) 

### Th e objectiv e o f th e soi l investigatio n stud y was : t o develo p informatio n o n soil-meta l level s i n th e Leadville
, Colorad o area ; t o evaluat e backgroun d soil-meta l levels ; t o identif y source s o f contamination ; an d t o delineat e th e exten t o f soil s contaminatio n i n th e stud y area . This stud y 

### focuse d o n soil s contaminate d wit h lead

. Th e stud y are a wa s centere d ove r th e town s o f Leadvill e an d Stringtown
, an d extende d outsid e o f th e Populate d Stud y Are a dow n th e Californi a Gulch an d th e Arkansa s River

. A.3.3. 1 Method s 

### A n intensiv e soi l samplin g progra m i n Leadville
, Stringtown
, an d th e vicinit y wa s conducte d fro m Augus t throug h Octobe r o f 1987

. Mos t cit y block s i n Leadvill e an d Stringtow n tha t wer e no t sample d i n th e 198 6 CD L (E-S
, 1987 ) surve y conducte d b y E-S
, wer e sample d a s par t o f thi s soil s investigatio n program

. I n eac h cit y block , a relativel y undisturbe d are a wa s selected , an d a rando m poin t wa s chose n withi n th e are a fo r sampling

. Surfac e soi l sample s ( 0 t o 2 inches ) wer e collecte d wit h a trowel

. Subsurfac e soi l sample s fro m 2 t o 6 inche s wer e collecte d 

### wit h a 3 1/4-inc h auge r an d fro m 6 t o 1 2 inche s wit h a 2 3/4-inc h auger . A fe w samples wer e Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 1996 Documen t Control No

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. epa\soils-ri\append-a.ju nno t randoml y selecte d a t a sit e becaus e o f samplin g constraint s impose d b y th e landowne r o r limite d samplin g area . 

### Additiona l soi l sample s wer e take n fro m tes t pits ; th e tes t pit s wer e du g b y backho e t o a dept h
o f 5 fee t an d han d du g pit s t o a dept h o f 4 0 inches

. Soi l samples wer e collecte d i n eac h strat a o r soi l horizo n a t abou t 6-inc h interval s t o th e botto m o f th e pit

. A.3.3. 2 Result s 

### Mos t o f th e soil s o f Leadvill e ten d t o hav e loam y A-horizon s abou t 6 t o 1 0 inche s thic k tha t 

### overli e sandy , gravelly , an d cobbl y subsoils

. Th e A-horizon s ar e al l highe r i n lea d concentration s tha n th e underlyin g subsoils

. Th e A-horizon s absor b metal s mor e readil y 

### compared t o th e sand y subsoils , becaus e o f thei r highe r exchang e capacities

. 

### Seve n backho e pit s wer e excavate d i n th e tow n o f Leadville
, an d samples wer e collecte d a t 2

- t o 6-inc h interval s t o a dept h o f 5 feet

. Thre e backho e pit s locate d eas t o f Harriso n Avenu e i n Leadvill e wen t throug h u p t o 2. 5 fee t o f min e waste s befor e encounterin g burie d A-horizon s i n nativ e soil

. Th e to p 2 inche s o f th e burie d A-horizon s belo w th e min e wast e wer e analyze d an d 

### foun d t o hav e lea d concentration s o f 950 , 3,750 , an d 75 0 mg/kg

. Th e min e waste s overlyin g 

### th e A-horizon s ha d lea d concentration s greate r tha n 2,50 0 mg/kg

. Wes t o f Harriso n th e min e waste s wer e no t a s thic k i n th e remainin g fou r backho e pits

. On e pi t ha d 8 inche s o f wast e 

### overlyin g th e nativ e soil

. I n 5 4 han d du g location s sample s wer e collecte d fro m 0 t o 2 inches, 2 t o 6 inches , an d 6 t o 1 2 inches

. Eigh t sample s wer e collecte d fro m cellar s an d craw l space s 

### o f Leadvill e houses , an d on e wa s collecte d fro m unde r th e lo g foundatio n o f a n ol d cabi n i n Jacktown

. Thre e houses , constructe d i n 1898 , 1882 , an d 1880 , ha d 2,120 , 330 , an d 19 0 mg/k g o f lead , respectively , i n th e A-horizon s unde r th e foundations

. Lea d concentration s i n sample s 

### take n fro m A-horizon s fro m unde r the foundation s o f the remainin g fiv e house s range d fro m 5 0 t o 1,26 0 mg/kg

. Thes e fiv e house s wer e constructe d afte r 1900

. The concentration o f lea d foun d i n th e burie d A-horizo n unde r th e cabi n a t Jacktow n wa s 2,82 0 mg/kg

.
Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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### Th e majo r source s o f lea d contaminatio n i n Leadvill e wer e describe d a s mechanicall y transporte d min e wast e roc k an d tailings , smelte r fumes , an d slag

. Thes e min e waste s cove r significan t 

### part s o f Leadvill e an d wer e apparentl y mechanicall y transporte d b y ma n an d sprea d throughout th e town

. Th e min e waste s ar e thickes t o n th e eas t sid e o f Leadville

. Th e dat a sugges t tha t min e wast e roc k ha s u p t o 25,00 0 mg/k g o f lea d an d tha t value s o f 1,00 0 t o 10,00 0 mg/k g ar e common . Sla g represent s a smalle r volum e o f wast e materia l tha n eithe r tailing s o r wast e roc k an d i s 

### foun d throughou t th e Leadvill e area . On e o f thre e gra b samples o f sla g wa s foun d t o contai n 14,92 0 mg/k g o f lead

. A s earl y a s 1881 , sla g wa s use d a s a roa d grave l throughout th e tow n o f Leadville

. Sla g an d wast e roc k wer e als o use d a s a railroa d ballas t b y th e Denve r an d Ri o Grand e Railroa d a s earl y a s 1887

. 

### I n th e Californi a Gulc h an d Stringtow n are a th e lea d concentration s excee d 1,00 0 mg/kg , an d 

### larg e portions o f th e are a hav e concentration s o f lea d abov e 2,50 0 mg/kg

. A fe w area s ar e abov e 5,00 0 mg/k g o f lead

. Abou t hal f o f Stringtow n ha s lea d concentration s abov e 2,50 0 mg/kg

. 

### A.3. 4 Residentia l Surfac e Soil s an d Househol d Dus t Samplin g (Walsh

. 1990 ) Th e objectiv e o f thi s samplin g progra m wa s t o obtai n soil s an d househol d dus t sample s tha t wer e analyze d fo r EP A Targe t Compoun d Lis t (TCL ) metal s an d meta l speciatio n analysi s fo r lead

. 

### A.3.4. 1 Samplin g Procedure s Soi l sample s fro m a dept h o f 0 t o 2 inche s wer e take n wit h a stainless stee l scoop

. Th e soil s 

### wer e place d i n a stainless stee l bow l fo r th e purpos e o f generatin g a composit e sample

. Househol d dust sample s wer e collecte d usin g a persona l ai r samplin g pum p an d a polystyren e 

### samplin g cassett e containin g a 0. 8 micrometer s (/*m ) mixe d cellulos e este r filter

. A stainles s stee l nozzl e wit h a 1-centimeter (cm ) X 5-c m openin g wa s connecte d t o th e filte r cassett e wit h Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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### Tygon ®

tubing

. The ai r pum p wa s adjuste d t o a samplin g flo w rat e o f 2 liter s pe r minut e (f/min)

. 

### Eac h floo r are a wa s sample d wit h th e ai d o f a plexiglas s templat e wit h a 22-c m X 22-c m opening

. Thre e passes , eac h uni-directional , wa s mad e ove r th e are a expose d b y th e template

. Th e secon d pas s wa s mad e perpendicula r t o th e firs t an d th e thir d pas s wa s mad e a t a 4 5° angl e 

### t o th e secon d pass

. Whe n dee p pil e carpet s wer e sampled , a fourt h pas s wa s mad e a t a 90 angl e t o th e thir d pass

. A.3.4. 2 Samplin g Location s Residentia l soil s wer e sample d i n th e Leadvill e an d Stringtow n communitie s t o provid e dat a o n potentia l exposur e pathway s fo r minin g wast e t o inhabitant s i n thes e communities

. Fift y soi l 

### samples wer e take n fro m Leadvill e an d 1 0 fro m Stringtown

. Thes e samples wer e take n fro m fron t and/o r backyar d residentia l area s wher e th e childre n spen t mos t o f thei r outdoo r tune

. A 

### total o f fiv e location s wer e sample d an d composite d fo r eac h residentia l location

. Househol d dus t sample s wer e take n fro m area s frequente d b y children

. Thes e location s includ e th e 

### children s bedroom ; th e kitchen ; an d th e livin g room . Usin g th e templat e an d personal ai r samplin g pump , composit e dus t sample s wer e take n a t eac h residence

. A.3.4. 3 Analysi s o f Surfac e Soi l and Dus t Sample s 

### Soi l an d dus t sample s wer e analyzed fo r lea d b y Graphit e Furnac e Atomi c Absorptio n (GFAA)

. A.3.4. 4 Result s 

### Lea d wa s reporte d i n al l soi l an d dus t sample s collecte d durin g thi s study

. Lea d concentration s 

### i n soi l range d fro m approximatel y 50 0 mg/k g t o 4,98 0 mg/kg

. Lea d concentration s i n dus t samples range d fro m 27 0 mg/k g t o 5,44 0 mg/kg

. The highest dust-lea d valu e o f 5,44 0 mg/k g wa s reporte d i n Stringtown

. Residential-Populate d

Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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. epa\soils-ri\append-a.ju nA.3. 5

Soil s Investigatio n Dat a Repor t (CDM

. 1994 ) 

### Th e objective s o f th e CD M Soil s Investigatio n Dat a Repor t were :
• T o determin e th e concentratio n o f element s identifie d b y th e EP A a s bein g o f potentia l concer n an d thei r distributio n i n sit e soils

. Thes e element s includ e lea d (Pb)
, arseni c (As) , zin c (Zn) , an d cadmiu m (Cd)

. • T o provid e dat a necessar y t o characteriz e th e source s o f thes e element s s o tha t th e 

### source s ma y b e identifie d an d controlle d i n a manne r tha t woul d mitigat e additiona l sourc e impac t t o th e sit e an d it s residents

. Thi s stud y focuse d o n characterizin g th e nature, extent , and distributio n o f potentia l element s o f concer n a t th e Californi a Gulc h Site

. A significan t numbe r o f soi l sample s wer e take n fro m th e Populate d Stud y Area , wit h a n emphasi s o n th e characterizatio n an d distributio n o f lead

. A.3.5. 1 Soil s Investigatio n Sampl e Location s Soi l sampl e location s wer e establishe d b y a gri d patter n prior t o th e fiel d investigatio n an d detaile d i n th e CDM' s Sampling an d Analysis Plan (1991)

. Thre e categorie s o f samplin g location s wer e identifie d i n thi s study

. A primar y gri d (PG ) pattern , oriente d N 45 W , wa s 

### establishe d i n th e Populate d Stud y Are a wit h samplin g point s space d a t 500-foot intervals

. Outsid e o f the Populate d Stud y Area, a n extende d gri d (EG ) patter n wa s establishe d wit h samplin g point s locate d a t 500-foo t o r 1,000-foo t intervals

. Th e E G samplin g location s wer e determine d b y extendin g th e P G gri d outsid e o f th e Populate d Stud y Area

. Th e gri d samplin g location s for th e CD M soil s investigatio n are show n i n Plat e I

. Th e decisio n t o sampl e soil s i n th e E G wa s base d o n analytical result s obtaine d fro m P G samples

. Base d o n analytica l result s fro m soi l sampl e analysi s fro m th e P G an d E G grid s an d requirement s t o augmen t geostatistica l 

### interpretation , a n S G wa s use d t o identif y soi l samplin g location s a t intermediat e distance s betwee n certai n P G an d E G locations

. A fourt h categor y o f samplin g locations , exposur e poin t (EP)
, wa s identifie d independentl y o f th e gri d patter n an d wa s base d o n increase d probabilit y o f exposur e t o th e public

. Th e samplin g gri d location s ar e show n i n Plat e 1

. Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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### Soi l sampl e gri d point s wer e locate d i n th e fiel d usin g expande d scal e ( 1 inc h = 10 0 fee t o r 

### 1 inc h = 20 0 feet ) bas e map s b y measurin g fro m physica l feature s suc h a s buildings , roads , 

### powe r lines , o r othe r landmark s show n o n th e maps

. I n undevelope d areas , th e sampl e locatio n wa s transferre d t o hig h resolutio n aeria l photograph s ( 1 inc h = 20 0 feet) , an d gri d point s wer e locate d relativ e t o physica l feature s show n o n th e photograph

. Location s wer e transferre d b y 

### overlayin g th e photograp h on th e sit e bas e ma p showin g th e sampl e location , usin g physica l feature s show n o n bot h th e ma p an d photograph , an d markin g th e locatio n o n th e photograph

. Eac h plotte d samplin g poin t wa s locate d o n th e ma p o r aeria l photograp h a t th e fiel d facilit y an d cross-checke d o n th e applicabl e parce l map

. A.3.5. 2 Soi l Samplin g 

### Eac h samplin g point wa s locate d o n th e ma p o r aeria l photograp h an d cross-checke d o n a n applicabl e parce l ma p at th e fiel d facility

. A t eac h samplin g location , a triangula r plasti c template , 1 mete r lon g o n eac h side , wa s pkce d ove r th e samplin g point wit h th e cente r point


### o f th e templat e positione d ove r th e sampl e point an d wit h on e point o f th e triangula r for m 

### aligne d alon g th e northeast-southwes t

trendin g gri d line

. Thre e excavation s wer e made, on e a t
eac h point o f th e triangula r template

. Eac h excavatio n wa s du g t o a dept h o f 2 1 inches, exposin g a n approximat e 18-inch-wid e soi l samplin g face

. Soil s wer e take n fro m th e followin g sampl e dept h intervals ; 0 t o 1 , 1 t o 2 , 2 t o 6 , 6 t o 12 , an d 1 2 t o 1 8 inches

. 

### A.3.5. 3 Samplin g Metho d 

### A flat , four-side d scraper wa s use d t o scrap e clea n th e soi l surfac e i n th e excavate d pi t fro m whic h soi l sample s wer e taken

. Thi s procedur e wa s repeate d i n eac h o f th e thre e excavations

. A separat e scrape r wa s use d fo r eac h o f th e thre e samplin g faces , an d eac h soi l dept h interva l
wa s scrape d clea n wit h a n unuse d sid e o f th e scrape r beginnin g wit h th e uppe r mos t samplin g interva l an d workin g dow n th e face

. Th e procedur e calle d fo r scrapin g on e fac e a t a time , beginnin g wit h th e 0

- t o 1-inc h samplin g interva l an d workin g dow n th e fac e o f th e excavation

. 

### Soi l sample s fro m eac h samplin g interva l wer e collecte d int o a separat e pre-labele d cu p 

### beginnin g wit h th e 12

- t o 18-inc h samplin g interva l an d workin g u p th e fac e o f th e excavate d Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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. epa\soils-ri\append-a.ju npi t towar d th e surface

. Soi l fro m th e roo t zone , whe n present , wa s include d i n th e 0

- t o 1

- an d 

### 1

- t o 2-inc h samplin g interval

. Th e thre e excavate d pit s generate d a tota l o f 1 5 samples pe r sampl e location

. The thre e sample s fro m the sam e sampl e dept h interva l wer e composite d and 

### place d i n a plasti c bag , labeled , an d the n place d i n a secon d plasti c bag

. Sample s collecte d fro m th e fiel d wer e sen t t o th e fiel d facilit y wher e th e samples wer e logge d i n an d th e sampl e I D numbe r o n th e plasti c ba g wa s cross-checke d agains t th e fiel d lo g sheets

. Al l sample s wer e handle d i n accordanc e wit h establishe d chain-of-custod y procedures

. 

### A.3.5. 4 Analysi s o f Soi l Sample s Soi l sample s wer e prepare d fo r XR F an d CL P analysi s at th e fiel d facilit y supportin g th e soil s 

### investigation

. Sampl e preparatio n include d dryin g th e sampl e t o a consistentl y lo w moistur e leve l t o facilitat e th e followin g subsequen t steps ; an d sieving , weighing , splitting , an d grinding

. 

### Th e sample s wer e sieve d t o produc e a fractio n containin g particle s > 2 m m an d a secon d fractio n containin g sampl e particle s < 2 mm . Th e sampl e fractio n represente d b y < 2 m m 

### particl e siz e wa s separate d int o tw o fractions , th e firs t representin g particle s < 250 jw m an d th e secon d fractio n representin g particle s < 2 m m t o > 25 0 /*m

. Th e soi l sampl e fraction s wer e 

### the n groun d t o produc e a sampl e o f unifor m particl e siz e fo r subsequen t analysi s b y XRF

. Twenty-fiv e percen t o f th e sample s representin g th e < 25 0 /t m particl e siz e wer e als o analyze d fo r metal s includin g lead

. Th e othe r portio n o f th e split sampl e wa s archive d fo r futur e us e an d possibl e CL P analysis

. Soi l sample s wer e analyze d b y XR F fo r 1 1 element s includin g As , Cd
, Zn , an d Pb

. Twenty



### fiv e percen t o f th e samples wer e also analyze d usin g CLP-specia l analytical service s (SAS ) protocol

. Sample s wer e analyze d usin g th e inductivel y couple d plasm a technique

. I f lea d 

### concentration s wer e reporte d belo w th e contrac t require d detectio n limit s (CRDLs)
, th e sample s wer e the n analyze d b y GFAA

. Th e samples destine d fo r CL P analysi s wer e selecte d base d o n XR F analytica l results

. 

### T o produc e hig h qualit y analytica l dat a usin g th e XR F analytica l technique, calibratio n standard s wer e selecte d t o includ e specifi c analytes , contaminant s o f concern , an d matri x material s know n Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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### t o b e present i n sit e soi l samples

. Thi s wa s necessar y i n orde r t o minimiz e matri x effect s an d replicat e spectra l response

. A se t o f 6 0 soi l sample s previousl y collecte d fro m th e Californi a Gulc h Sit e wer e obtaine d fo r th e purpos e o f XR F instrumen t calibration

. These s calibratio n soi l 

### standard s wer e collecte d durin g th e Residentia l Soil s an d Dus t Surve y (CDM
, 1993)

. O f th e 6 0 calibratio n soi l standards , onl y 3 0 wer e selecte d fo r initia l fiel d calibration

. Thi s selectio n wa s 

### base d o n th e concentratio n distributio n o f th e contaminant s o f concer n i n thes e tentativ e calibratio n soi l standards

. Fo r fina l calibratio n o f th e XR F instrument , onl y 1 5 o f th e 3 0 

### calibratio n soi l standard s wer e retaine d fo r recalibratio n purposes , an d 1 5 sample s collecte d durin g th e fiel d investigatio n wer e adde d t o serv e a s calibratio n soi l standards

. Thes e calibratio n soi l sample s wer e processe d i n accordanc e wit h sampl e preparatio n procedure s describe d i n thi s 

### section an d the n submitte d for analysi s b y tw o CL P laboratories

. Th e bul k versio n o f thes e calibratio n soi l sample s wa s als o analyze d b y ye t a thir d CL P laboratory

. Thi s wa s necessar y becaus e th e analytica l results , fo r th e calibratio n soi l sample s tha t wer e t o b e use d a s calibratio n standards , wer e no t availabl e durin g th e fiel d investigation

. Therefore , durin g th e fiel d 

### investigatio n th e XR F instrumen t wa s calibrate d usin g analytica l dat a obtained b y th e CL P analysi s o f th e bul k versio n o f th e calibratio n soi l standards

. Followin g th e fiel d samplin g investigation , the XR F instrumen t wa s recalibrate d usin g analytica l dat a obtaine d fro m the analysi s o f soi l calibratio n standards , an d al l o f th e origina l analytical dat a wer e reprocesse d usin g th e new calibratio n factors

. A.3.5. 5 Result s Fro m the CD M samplin g program , the statistica l result s wer e abl e t o assig n dat a qualit y level s 

### fo r XR F analyses

. Thes e level s ar e a s follows : EP A Leve l ffl

. XRF-analyze d element s qualifyin g a s Leve l i n ar e Ca
, Cu
, Fe , 

### Pb
, Mn , an d Zn

. Thes e dat a ca n b e utilize d fo r suppor t o f engineerin g studie s suc h a s th e F S an d ma y b e use d t o asses s ris k i n th e endangermen t assessment

. EP A Leve l n . XRF-analyze d element s qualifyin g a s Leve l n ar e Ba
, Cd
, an d Ar

. Thi s leve l dat a ma y b e use d t o suppor t engineerin g studies

. Thi s dat a shoul d b e use d wit h cautio n fo r endangermen t assessmen t purposes

. Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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### Geostatistica l

analysi s an d concentratio n contou r map s wer e use d t o characteriz e th e spacia l distributio n o f As , Ba
, Ca
, Cu
, Fe , Mn , Hg , Pb
, an d Zn

. Thes e contou r map s wer e produce d for eac h o f th e dept h interval s an d for al l soil s an d native/undisturbe d soils

. Th e contou r map s 

### fo r al l soil s characteriz e concentratio n distributions tha t ma y b e use d fo r F S an d E A purposes

. Th e native/undisturbe d contou r map s ma y b e use d i n conjunctio n wit h result s fro m th e meta l speciatio n progra m t o characteriz e relativ e sourc e impacts

. 

### A.3. 6 Soil s Investigation

. Californi a Gulc h Stud y Are a (Walsh

. 1992a ) Th e objective s o f th e soi l investigatio n wer e t o develo p a soi l an d a surficia l geolog y ma p o f th e stud y are a t o evaluat e a possibl e correlatio n betwee n soi l ma p units , surficia l geology , an d soi l meta l concentrations.Th e

objective s o f surficia l geologi c mappin g wer e t o compil e existin g surficia l geologic informatio n o f th e stud y are a o n t o on e ma p an d fiel d chec k th e mappin g t o suppor t th e domai n analysis

. Thi s include d fiel d checkin g existin g Soil Conservatio n Servic e (SCS ) soi l ma p unit s an d delineation s an d descriptio n o f soi l an d surficia l material s i n th e CD M 

### soi l samplin g progra m (CDM
, 1991a)

. A secondar y objectiv e o f geologi c mappin g wa s t o provid e informatio n relativ e t o th e origi n o f naturall y occurrin g surficia l materials

. T o accomplis h thes e objectives , specifi c task s fo r th e soi l investigatio n include d th e following :
• Identif y and delineat e soi l ma p units

. • Describ e th e soil s an d surficia l material s t o a dept h o f 1 8 inches

. • Defin e th e physica l an d chemica l characteristic s o f th e soils

. • Estimat e th e percentag e o f huma n artifacts , min e wast e rock , tailing s materials , smelte r waste , clea n fill , an d sla g presen t i n th e soils

. I n th e populate d region s o f th e Residentia l Stud y Area, a n Orde r I soi l surve y wa s conducted

. Th e Orde r I soi l surve y include s ma p unit s tha t ar e mainl y constitution s an d som e complexes , i n whic h phase s o f soi l serie s wer e identified

. Th e minimu m ma p uni t siz e delineatio n i n th e 

### populate d are a wa s approximatel y 0.2 5 acres . Initia l soi l ma p unit s wer e base d o n th e Soil Survey ofChaffee-Lake Area, Colorado, an d parts o f Chaffee an d Lake Counties (Walsh , 1992a)

. Residential-Populate d

Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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. epa\soils-ri\append-a.ju nTh e inventor y o f soi l proceede d i n tw o stages

. Guideline s an d procedure s outline d i n Soi l 

### Taxonom y an d Key s t o Soi l Taxonom y (Walsh , 1992a ) wer e use d i n the firs t stag e fo r the purpos e o f identification , description , an d characterizatio n o f soil s withi n the stud y area . The secon d stage involve d mappin g th e distributio n o f soil s an d min e wast e materials

. Soi l sample s 

### fro m approximatel y 40 6 shallo w pit s an d 9 backho e pit s wer e take n fro m th e residentia l stud y area . A.3.6. 1 Geolog y Th e geolog y o f th e easter n portio n o f th e Californi a Gulc h Sit e i s dominate d b y th e foothill s o f 

### th e Mosquit o Range

. This are a i s composed o f porphyry , rhyolite , granite , an d othe r intrusiv e igneou s rocks

. Th e wester n portio n o f th e Californi a Gulc h Site
, includin g th e tow n o f Leadvill e an d th e area s t o th e wes t an d sout h o f Leadvill e withi n th e Populate d Stud y Area, consist s o f 

### thic k deposit s o f unconsolidate d glacia l outwas h material s for m th e Pleistocen e Period

. Thes e unconsolidate d material s are derive d fro m variou s type s o f lithologie s existin g i n th e Mosquit o Rang e eas t o f Leadville
, an d includes : severa l varietie s o f porphyry , rhyolite , granite , an d othe r 

### intrusiv e igneou s rocks ; an d quartzite , dolomite , limestone , an d sandstone

. Thes e material s wer e transporte d an d redeposite d b y glacial an d fluvia l processes

. Thes e deposit s ar e poorl y sorted , loose , an d porous

. Th e Lak e Fork Traile r Par k area , locate d i n th e extrem e western portio n o f 

### the Californi a Gulc h Site
, i s compose d o f youn g Holocen e strea m terrac e deposit s an d youn g Holocen e strea m channe l an d floodplai n deposits

. Numerou s fault s exis t withi n th e are a o f th e Californi a Gulch Site

. Th e Valentin e Faul t i s locate d withi n th e Residentia l Stud y Are a an d th e Pender y Faul t i s locate d directl y t o th e sout h
o f th e southern boundar y o f th e stud y area . A.3.6. 2 Soil s 

### Soil s o f th e stud y are a hav e forme d fro m thre e majo r distinc t paren t materials : (1 ) soil s i n th e 

### easter n portio n o f th e stud y are a forme d fro m a variet y o f igneous , sedimentary , an d metamorphi c rocks , whic h for m the stee p foothill s o f the Mosquit o Range ; (2 ) soil s tha t occu r Residential-Populate d

Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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. epa\soils-ri\append-a.ju nthroughou t

Leadvill e an d tha t exten d t o th e Arkansa s Rive r Valle y wer e derive d primaril y fro m 

### weatherin g o f poorl y consolidate d glacial drif t an d outwas h fa n deposit s o f th e Pleistocen e glacia l epoch ; (3 ) soil s alon g th e Arkansa s Rive r Valle y wer e derive d fro m recen t (Holocene ) floodplai n 

### deposits

. Soil s occurrin g o n th e stee p foothill s belon g predominatel y t o th e Alfisol s soi l order

. Soil s o n th e glacia l terrace s an d moraine s an d th e outwas h fan s belon g t o th e Alfisols , Mollisols , an d 

### Histosol s soi l orders

. Soil s occurrin g o n lo w rive r terraces , swales , and floodplain s alon g th e Arkansa s Rive r belon g t o th e Mollisols , Histosols , Inceptisols , an d Entisol s soi l orders

. Alfisol s ar e light-colore d soil s tha t hav e geneti c horizon s enriche d i n silicat e cla y i n th e subsoi l relativ e t o th e overlyin g horizons

. Thes e soi l occu r on uplan d landscap e positions

. Mollisol s 

### ar e soil s tha t hav e a thick , dark-colored , base-enriche d surfac e horizo n du e t o th e accumulatio n 

### an d decompositio n o f organi c matte r i n thes e layers

. They generall y occu r alon g strea m channel s an d terrace s suc h a s Californi a Gulch

. Histosol s ar e organic-ric h soil s tha t contai n a t least 1 2 percen t organi c carbo n b y weigh t an d ar e generall y mor e tha n 4 0 centimeter s thick

. They occu r i n a marsh y are a nea r Adelaid e Park

. Inceptisol s ar e soil s tha t contai n som e degre e o f pedogeni c development

. The y generall y exhibi t subsurfac e structura l developmen t an d hav e 

### som e colo r developmen t belo w th e A horizon

. Entisol s ar e soil s withou t natura l pedogeni c horizon s o r wit h onl y th e beginning s o f suc h horizons

. The y typicall y hav e thi n A horizon s ove r paren t material

. A.3.6. 3 Soi l Samplin g 

### Pedon samplin g site s wer e excavate d wit h a backhoe

. A trenc h 3

- t o 5-meter s (m ) lon g wa s excavate d t o a maximu m dept h o f 5 feet

. Th e trenc h wa s opene d t o a widt h o f approximatel y 1. 5 m . A steppe d entr y wa y wa s excavate d a t a righ t angl e t o th e mai n trenc h tha t serve d a s 

### a n exit/entry rout e durin g sampling

. Soi l pedon s wer e sample d b y recognize d soi l horizon s an d 

### b y dept h increments

. Th e soi l horizon s wer e identifie d accordin g t o criteri a i n Soi l Taxonom y Soi l Surve y Staff
, 1975 , 199 0 (Walsh , 1992a)

. Soi l profile s wer e evaluate d from : backho e pit s 

### du g t o a dept h o f 6 0 inches ; soi l samplin g pit s du g b y CD M t o a dept h o f 2 2 inches ; an d soi l Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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. epa\soils-ri\append-a.ju n

### observation

pit s du g b y Wals h t o a dept h o f 2 0 t o 3 0 inches

. Soi l sample s wer e take n fro m th e 0

- t o 1- , 1

- t o 2- , 2

- t o 6- , 6

- t o 12- , an d 12

- t o 18-inc h dept h intervals

. Thes e soi l increment s ar e identical t o thos e use d b y CD M i n th e soil s investigatio n (CDM
, 1991a)

. 

### Soil s wer e sample d an d examine d fo r th e presence o f min e wast e material s an d material s tha t
wer e historicall y use d i n minin g activities , suc h a s slag , min e wast e rock , tailings , smelte r waste , refractor y bricks , coal , charcoal , cinders , glas s fragments , metalli c fragments , asphalt , 

### manganes e oxides , dar k colore d dolomite , and iro n staine d fragments

. Th e percentage s o f 

### manmad e material s presen t i n soi l wer e estimate d fo r al l soi l horizon s usin g th e followin g percentag e increments ; 0. 0 t o 0.1 , 0. 1 t o 1.0 , 1 t o 5 , 5 t o 25 , 2 5 t o 50 , 5 0 t o 75 , an d 7 5 t o 100

. 

### Thes e dat a wer e use d t o describ e th e soi l characteristic s o f eac h ma p uni t fo r th e surve y are a an d t o hel p identif y th e natur e an d kin d o f contaminant s i n th e soi l ma p unit

. 

### A.3.6. 4 Soi l Samplin g Metho d 

### Th e side s o f th e soi l pedon s wer e prepare d for samplin g b y scrappin g th e entir e fac e t o remov e loosene d debri s an d rocks

. Next , startin g wit h th e lowermost soi l horizo n o r dept h increment , the fac e o f the pedo n wa s scrappe d wit h a plasti c scrappe r t o provid e a fresh , non-cross
contaminate d surfac e for sampling

. Usin g a stainless stee l trowel , th e soi l wa s sample d and allowe d t o fal l int o a plasti c 16-ounc e cup

. Horizo n an d dept h incremen t samples wer e take n fro m tw o separat e area s t o ensur e tha t representativ e samples wer e taken

. Tw o t o thre e cup s o f soi l materia l wer e composite d i n a stainless stee l mixin g bow l an d the n homogenized

. A 

### portio n o f th e homogenize d sampl e wa s pkce d i n a 16-ounc e glas s ja r for subsequen t analysi s b y th e laboratory

. A.3.6. 5 Surficia l Geologi c Mappin g Delineatio n o f surficia l Quaternar y geologi c unit s wa s base d o n a revie w o f existin g informatio n 

### an d fiel d observation s o f topographic positio n an d relief , surfac e morphology , sedimentology , an d stratigraphy

. Fiel d reconnaissanc e mappin g o f surficia l geologi c unit s wa s compare d t o 

### observation s fro m aeria l photographs

. Stere o aeria l photograph s provide d a n enhance d three

Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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. epa\soils-ri\append-a.ju n

### dimensional

vie w o f larg e portion s o f th e stud y area . Thi s enable d observation o f large-scal e feature s no t recognizabl e fro m a groun d perspectiv e an d allowe d compariso n o f similar geologi c 

### an d topographi c feature s ove r th e stud y area . Photographi c identificatio n o f thei r geomorphi c 

### surface s associate d wit h fiel d mappin g unit s wa s base d o n textural , tonal , an d colo r characteristic s uniqu e t o eac h surface

. Th e three-dimensiona l aspec t o f th e stere o photograph s 

### allowe d th e observatio n o f topographi c relationship s betwee n unit s a s wel l a s thei r surfac e topography

. A.3.6. 6 Laborator y Analysi s 

### Soi l pedo n sample s wer e analyzed , usin g analytica l method s employe d fo r agronomi c parameter s identifie d b y th e America n Societ y o f Agronom y (ASA ) o r th e U.S

. Departmen t o f Agricultur e 

### (USDA)
, fo r th e followin g physica l an d chemica l parameters : p H , Saturate d Past e 

### Conductivity
, Saturate d Past e Catio n Exchang e Capacit y Carbon
, Organi c Lim e 

### Acid/Bas e Potentia l Sulfur
, Tota l Neutralizatio n Potential Particl e Siz e Analysi s Bul k Densit y The sample s wer e als o analyze d fo r lead , arsenic , cadmium, an d zin c b y XRF

. 

### A.3.6. 7 Result s 

### Soil s Thi s sectio n present s th e result s o f th e soi l mappin g (Walsh , 1992 ) withi n th e stud y area . Fo r 

### clarit y an d simplicity , ma p unit s havin g simila r physica l an d chemica l characteristic s wer e Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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. epa\soils-ri\append-a.ju n

### combine

d t o for m generalize d ma p units

. A ma p o f th e stud y are a showin g generalize d ma p unit s i s show n i n Figur e 2- 3 (Volum e I)

. Th e acreag e o f eac h ma p uni t i s show n i n Tabl e A-7

. Withi n th e non-populate d stud y area , 42 6 shallo w observation s (t o 1 8 inches ) an d 1 3 backho e pit s wer e use d t o characteriz e an d ma p th e soils

. Thes e area s primaril y ar e compose d o f nativ e undisturbe d soils

. Area s no t compose d o f undisturbe d soil s i n non-populate d area s includ e th e 

### numerou s min e wast e pile s occurrin g i n th e easter n portio n o f th e stud y area ; area s consistin g o f erode d soils , suc h a s th e northwes t facin g hillsid e sout h o f th e forme r A V smelte r site ; th e forme r A V smelte r sit e whic h i s compose d o f sla g pile s an d slag/min e wast e mixe d wit h constructio n fill ; sla g an d tailin g pile s occurrin g i n variou s locations ; an d man y o f the majo r 

### drainages

. Thes e drainages , includin g Californi a Gulch
, portion s o f Evan s Gulch
, Orego n Gulch
, Malt a Gulch
, Stra y Hors e Gulch
, Littl e Stra y Hors e Gulch
, an d alon g th e Arkansa s Rive r 

### consis t o f alluvia l soil s mixe d wit h variou s type s o f min e waste

. Th e min e wast e pile s are eithe r sulfide

- o r carbonate-rich

. Th e sulfide-ric h pile s contai n littl e o r n o vegetation , ar e commonl y aci d generating , an d ar e basicall y wast e land

. Th e carbonat e wast e piles , o n th e othe r hand , d o contai n som e grasse s an d sagebrush

. Withi n th e Residentia l Stud y Area, 40 6 shallo w observation s (t o 1 8 inches ) an d 1 8 backho e pit s wer e use d t o characteriz e an d ma p th e soils

. Th e soi l ma p unit s an d lan d type s occurrin g withi n th e Residentia l Stud y Are a ar e show n i n Table s A- 8 an d A-9

. Soil s i n th e Cit y o f Leadvill e ar e predominatel y Leadvill e sand y loa m wit h overlyin g constructio n fill

. Th e constructio n fil l varie s 

### i n compositio n an d i n thickness , fro m a coupl e inche s t o mor e tha n 5 0 c m thick

. Th e fil l i s usuall y thicke r wes t o f Harriso n Street

. I n general , th e fil l i s ver y heterogenou s and commonl y contain s bric k fragments , glass , charcoal , slag , min e wast e rock , an d othe r debris

. Th e easter n 

### portio n o f the Cit y o f Leadvill e contain s numerou s min e wast e pile s and the Harriso n sla g pil e i s locate d i n southeas t Leadville

. 

### Soil s i n th e Stringtow n are a ar e predominantl y Pieria n gravell y sand y loa m wit h overlyin g fil l materia l whic h ma y contai n som e min e waste

. Bot h th e southwest an d northeas t end s o f Stringtow n are compose d o f alluviu m mixe d wit h mil l tailings

. Residential-Populate d

Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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. epa\soils-ri\append-a.ju n

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## I I Tabl e A- 8 

### Classificatio n o f Ma p Unit s fo r th e Residentia l Stud y Are a Soi l Inventor y M a p Uni t N o

. 3 4 5 7 8 9 1 1 1 3 1 6 2 0 2 1 2 2 2 5 2 6 3 0 3 4 4 0 4 2 4 5 4 6 5 0 5 5 5 7 5 9 M a p Uni t Nam e Leadvill e sand y loam , 3- 8 % slope s Leadvill e sand y loam , 3- 8 % slopes , erode d Leadvill e sand y loam , 3- 8 % slopes , disturbe d Leadvill e sand y loam , 3- 8 % slopes , wit h surfac e sla g Leadvill e sand y loam , 3-8 % slopes , disturbe d wit h constructio n fill , surfac e sla g an d cinder s Leadvill e sand y loam , 3-8 % slopes , wit h overlyin g min e wast e <5 0 c m thic k Leadvill e sand y loam , 3-8 % slopes , wit h overlyin g tailing s <5 0 c m thic k Leadvill e sand y loam , 3-8 % slopes , wit h overlyin g constructio n fil l <5 0 c m thic k Leadvill e sand y loam , 3- 8 % slopes , wit h overlyin g constructio n fil l > 5 0 c m thic k Leadvill e sand y loam , 3-3 5 % slope s Leadvill e sand y loam , 3-3 5 % slopes , erode d Leadvill e sand y loam , 3-3 5 % slopes , disturbe d Leadvill e sand y loam , 3-35 % slopes , wit h overlyin g min e wast e <5 0 c m thic k Leadvill e sand y loam , 3-3 5 % slopes , wit h overlyin g constructio n fil l < 5 0 c m thic k Newfor k gravell y sand y loam , 1- 3 % slope s Newfor k gravell y sand y loam , 1-3 % slopes , wit h overlyin g constructio n fil l <3 0 c m thic k Pieria n gravell y sand y loam , 3- 9 % slope s Pieria n gravell y sand y loam , 3-9 % slopes , wit h overlyin g min e wast e an d constructio n fil l >3 0 c m thic k Pieria n gravell y sand y loam , 3-9 % slopes , wit h overlyin g fil l >3 0 c m thic k Pieria n gravell y sand y loam , 3- 9 % slopes , disturbe d Troutvill e gravell y sand y loam, 3- 8 % slope s Troutvill e gravell y sand y loam , 3-8 % slope s Troutvill e gravell y sand y loam , 3-3 5 % slopes , disturbe d Troutvill e gravell y sand y loam , 3-35 % slopes , wit h overlyin g fil l Classificatio n

loamy-skeletal , mixe d Typi c Cryoboralf s loamy-skeletal , mixe d Typi c Cryoboralf s loamy-skeletal , mixe d Typi c Cryoboralf s loamy-skeletal , mixe d Typi c Cryoboralf s loamy-skeletal , mixe d Typi c Cryoboralf s loamy-skeletal , mixe d Typi c Cryoboralf s loamy-skeletal , mixe d Typi c Cryoboralf s loamy-skeletal , mixe d Typi c Cryoboralf s loam y o r loamy-skeletal , mixe d Typi c Cryoboralf s loamy-skeletal , mixe d Typi c Cryoboralf s loamy-skeletal , mixe d Typi c Cryoboralf s loamy-skeletal , mixe d Typi c Cryoboralf s loamy-skeletal , mixe d Typi c Cryoboralf s loamy-skeletal , mixe d Typi c Cryoboralf s sandy-skeletal , mixe d Typi c Cryaquoll s sandy-skeletal , mixe d Typi c Cryaquoll s sandy-skeletal , mixe d Typi c Cryoboroll s loam y or loamy-skeletal , mixe d Typi c Cryorthent s loam y or loamy-skeletal , mixe d Typi c Cryorthent s sandy-skeletal , mixe d Typi c Cryoboroll s loamy-skeletal , mixe d Psammenti c Cryoboralf s loamy-skeletal , mixe d Psammenti c Cryoboralf s loamy-skeletal , mixe d Typi c Cryoboralf s loamy-skeletal , mixe d Typi c Cryoboralf s w t n C O 

# e §

g S >

### Tabl e A- 9 Lan d Type s fo r th e Residentia l Stud y Are a Soil Inventor y Ma p Uni t No

. Ma p Uni t Nam e 7 0 7 1 7 2 7 4 8 0 8 1 8 2 9 1 9 2 10 2 Wast

e roc k piles

. Min e wast e — wast e roc k an d tailings

. Mixe d min e wast e wit h constructio n fil l >50-c m thick

. Constructio n fil l <50-c m thic k ove r min e waste

. Sla g piles

. Sla g — min e wast e — constructio n fil l >50-c m thick

. Mixe d sla g (>5 % sla g throughout ) wit h constructio n fil l > 50-c m thick

. Alluviu m wit h tailings

. Constructio n fil l mixe d wit h alluviu m an d tailings

. > 150-c m fil l materia l ove r nativ e soil

.

Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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. epa\soils-ri\append-a.ju n_ Th e Lak e For k Traile r Par k are a contain s Newfor k gravell y sand y loa m an d Newfor k gravell y sand y loa m wit h overlyin g fil l material

. Th e fil l materia l i s generall y les s tha n 3 0 cm thick

.

- w Turquois e

Lak e Estate s an d th e residentia l area s i n th e northwest portio n o f th e stud y are a 

### ^ (Silve r Hills , Ge m Valley , Fou r Seasons
, an d Matchles s Estates ) ar e compose d predominantl y o f nativ e soils , Leadvill e sand y loa m and Troutvill e gravell y sand y loam

. The A horizo n withi n



### — som e o f thes e area s ha s bee n partiall y o r completel y eroded

.

s ^ Physical an d Chemical Characterizatio n

o f Soi l Pedon s i n th e Stud y Are a 

### •* Th e result s o f physica l an d chemica l analyse s o f th e soi l backho e pit s (pedons ) locate d withi n th e Residential Soil s Stud y Are a ar e containe d i n Tabl e A-10

. Pedon s 0 1 an d 03 ar e locate d

^ outsid e o f th e stud y area ; however , the y ar e include d i n thi s discussio n becaus e o f thei r immediat e proximit y t o th e Residential Soi l Stud y Area

. 

### Th e pH o f th e saturate d soi l past e fro m pedon s withi n th e stud y are a range d fro m 4. 9 t o 8 wit h

v 

### a n averag e o f 6.3

. Th e p H o f a n undisturbe d Leadvill e sand y loa m (SIP-004 ) range d fro m 5. 1 t o 5.8

. Min e wast e material s withi n th e stud y are a ofte n exhibi t lowe r p H condition s tha n foun d s_rf" i _ _ i n nativ e soils

. For example , Pedo n 11 , whic h i s locate d i n Californi a Gulch jus t belo w th e forme r Or o Cit y site , exhibit s a p H o f 4 fro m 0 t o 6 0 inche s dept h - whic h correspond s t o th e ^v * occurrenc

e o f min e waste

. Highl y acidi c condition s ca n aris e fro m exposur e o f min e waste s t o 

### air

. I n additio n t o chemica l processes , biological processe s pla y a ver y important rol e i n determinin g th e acidit y o f soils

. Th e metaboli c processe s o f thiobasillus an d metallogeniu m organism s resul t i n th e oxidatio n o f pyrit e convertin g th e sulfid e int o sulfuri c acid

. The acid/bas e potentia l i s a measur e o f the maximu m potentia l acidit y agains t tota l neutralizin g v 

### materia l presen t i n soils

. Th e potentia l acidit y i s indicate d b y th e tota l sulfu r presen t i n th e soil

. A measur e o f th e neutralizatio n potentia l (capacity ) includes th e presenc e o f basi c cation s presen t '•^Nt f 

### a s carbonate s an d exchangeabl e cation s derive d fro m clays

. Th e tota l sulfu r an d neutralizatio n 

### potentia l are the n use d t o calculat e acid/bas e potentia l o f th e soil

. Natura l soil s withi n th e X Residentia l

Soil s Stud y Are a generall y exhibi t a positiv e acid/bas e potential

. Min e wast e

_ Residential-Populate d

Soil s Stud y Area Consolidate d Finding s Repor t APPENDI

X A Jun e 199 6 Documen t Control No

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. epa\soils-ri\append-a.ju nV

V

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### ^ 2 9 8 s2-»6J 3

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s ? a 2 H « R s 3 s « R 9 a 8 5 S 3 6 SPS S S S ? S S 8 ? ! 8 ? i f t 3 8 8 « S 3 S « 9 S S 5 ? « f t i S 6 S S ? S ? S S S ! 3

^ • < " S S - "" • 5 5 D " ! * ! S ^ " 5

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### I

Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

. 4800-37-020 5 Interi

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. epa\soils-ri\append-a.ju n

### ^ commonl

y exhibit s a negativ e acid/bas e potential , fo r exampl e Pedon s 0 3 an d 11 , whic h occu r outsid e th e Residential Soil s Stud y Area , contai n min e wast e an d correspondin g acid/bas e 

### « potential

s o f fro m - 5 t o -15 1 CaCO 3 

### /kton

. A n exampl e o f thi s neutralizatio n potentia l i s foun d i n pedo n SIP-01 2 locate d i n ma p uni t 09 , a Leadvill e sand y loa m wit h overlyin g min e waste

. Th e p H withi n th e min e wast e i s neutra l t o slightl y basic , an d th e averag e acid/bas e potentia l i s 88 , whic h suggest s tha t th e origi n o f th e predominan t min e wast e i s carbonat e base d material

. •-^

- Tota l sulfu r i n th e sam e horizo n range s fro m .0 1 t o . 5 percen t indicatin g tha t th e min e wast e als o contain s sulfid e bearin g waste

. A s thi s sulfid e minera l continue s t o b e oxidize d th e aci d


### v potentia l

wil l remai n hig h unti l the sulfid e i s depleted

.


### "• " Hig h catio n exchange capacit y (CEC ) i s associate d wit h hig h conten t o f organi c matte r an d t o a lesse r exten t wit h hig h cla y content

. Withi n th e stud y are a th e highes t CE C value , 23. 1
^ milliequivalent

s pe r 10 0 gram s (meq/10 0 g ) o f soil , wa s reporte d i n th e 0-t o 5-inc h incremen t 

### o f pedo n 006

. Pedo n 00 6 i s locate d i n a n undisturbe d Leadvill e sand y loa m soi l foun d i n ma p "
~ uni t 03

.

v Soi l Lea d Result s Th e soi l pedon s i n th e stud y are a wer e sample d b y bot h soi l horizo n an d specifi c dept h 

### increment s t o asses s th e exten t o f lea d contamination

. I t wa s foun d tha t lea d concentration s ar e generall y th e highes t i n th e uppe r mos t on e inc h o f soi l an d decrease wit h increase d soi l depth

. Th e highest lea d concentration s are associate d wit h min e wast e materials , fil l materia l o f unknow n origin , an d huma n artifacts

. Som e o f th e soi l pedon s wit h n o visibl e min e wast e an d fil l material s contai n elevate d level s o f lea d i n th e uppe r inc h o r tw o o f soil

. Lea d level s ten d t o dro p of f significantl y i n the nativ e soi l belo w the wast e o r fil l material

. A n exampl e o f thi s 

### i n Leadvill e i s foun d i n Pedo n 0 1 (incrementa l sample) , th e lea d leve l droppe d fro m 95 3 mg/k g i n th e 0 t o 1 inc h interval , whic h correspond s t o th e occurrenc e o f slag , t o 19. 5 mg/k g belo w 2 inche s dept h i n th e undisturbe d nativ e soil

. Pedo n 014 , locate d i n soi l ma p uni t 1 6 (Leadvill e sand y loam wit h overlyin g constructio n fil l > 5 0 c m thick) , consist s o f fil l materia l fro m 0 t o 

### 3 5 inches

. Th e highes t lea d concentratio n (6,41 0 mg/kg ) i n thi s pedo n occur s i n fil l materia l Residential-Populate d

Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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. epa\soils-ri\append-a.ju n

### fro m 2 2 t o 2 5 inche s depth , an d the n concentration s decrease t o les s tha n 10 0 mg/k g i n th e nativ e soil

. Lea d concentration s averag e 1,86 1 milligram s pe r kilogra m (mg/kg ) i n th e 0 t o 1 inc h interval , 

### 1,49 9 mg/k g i n th e 1 t o 2 inc h interval , decrease t o 48 6 mg/k g i n th e 2 t o 6 inc h interval , an d averag e les s tha n 30 0 mg/k g fro m 6 inche s t o 1 8 inche s depth

. I n surfac e horizon s o f th e soi l pedon s containin g min e wast e o r fil l material , P b concentration s ar e commonl y greate r tha n 2,00 0 mg/k g an d rang e fro m 44 3 mg/k g t o 10,90 0 mg/kg

. I n pedon s withou t visibl e min e wast e 

### an d fil l materia l i n th e A horizon, P b concentration s ar e generall y les s tha n 60 0 mg/k g an d rang e 

### fro m 14 3 mg/k g t o 1,88 0 mg/kg

. Lea d value s generall y decreas e t o less tha n 10 0 mg/k g a t depth s belo w 3 t o 1 2 inche s i n pedon s wit h n o visibl e min e wast e o r fil l material

. Arseni c concentration s averag e 8 0 mg/k g i n th e 0 t o 1 inc h interval , 6 2 mg/k g i n th e 1 t o 2 inc h interval , 5 9 mg/k g i n th e 6 t o 1 2 inc h interval , an d dro p belo w 2 0 mg/k g fro m 6 t o 1 8 inches

. Soi l 

### pedons withou t visibl e min e wast e an d fil l materia l contai n les s tha n 5 0 mg/k g A s i n th e surfac e 

### horizo n an d decreas e t o les s tha n 1 0 mg/k g belo w 3 t o 1 2 inches

. Cadmiu m concentration s 

### averag e 1 3 mg/k g i n th e 0 t o 1 inc h interval , 8 mg/k g i n th e 1 t o 2 inc h interval , an d decreas e t o 4 mg/k g o r les s belo w 2 inche s depth

. Zin c concentration s averag e 1,09 3 mg/k g i n th e 0 t o 1 inc h interval , 74 1 mg/k g i n th e 1 t o 2 inc h interval , an d decreas e t o 37 8 mg/k g i n th e 2 t o 6 inc h interval

. Zin c concentration s ar e generall y les s tha n 10 0 mg/k g i n th e substratum

. 

### Linea r regression wa s applie d t o lea d wit h selecte d agronomi c propertie s whic h demonstrate d tha t a correlatio n a t th e 9 5 percen t leve l o f significanc e exist s betwee n organi c carbo n an d lead

. O f th e fou r element s (lead , zinc , cadmium , an d arsenic ) lea d i s th e leas t mobil e i n soi l (Kabata

- Pendias
, 1984 ) becaus e o f th e insolubilit y o f lea d compounds

. Th e low solubilit y o f lea d compound s an d it s affinit y t o chelat e wit h organi c compounds , i n part , explai n th e presenc e o f 

### elevate d lea d concentration s i n th e uppe r 2 inche s o f undisturbe d soils

. Backgroun d Lea d Concentration s 

### A pre-minin g metal s stud y (Walsh , 1994 ) estimate d the backgroun d rang e fo r lea d i n uplan d 

### soil s t o b e betwee n 8 an d 15 0 mg/kg

. Th e majorit y o f th e residentia l stud y are a i s include d i n Residential-Populate d

Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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. epa\soils-ri\append-a.ju n

### uplan d

landscap e positions

. Thi s backgroun d rang e i s supporte d b y th e fac t tha t lea d level s i n nativ e undisturbe d soi l pedons withi n th e Residential Soil s Stud y Are a averag e less tha n 1 8 mg/k g belo w 6 inche s depth

. Furthermore , i n pedon s containin g min e wast e or fil l material , th e lea d concentration s i n th e underlyin g nativ e soi l generall y fall s belo w 10 0 mg/kg

. Schacklett e an d Boernge n (1984 ) an d Bowe n (1979 ) estimate d th e rang e o f lea d i n soil s o f th e wester n U.S

. t o b e < 1 0 t o 70 0 mg/k g an d 2 t o 30 0 mg/kg , respectively

. A.3. 7 Smelte r Remedia l Investigatio n Repor t fWalsh

. 1993 ) 

### Th e purpos e o f th e Smelte r Remedia l Investigatio n wa s t o collec t soi l dat a an d historica l smelte r informatio n t o identif y an d evaluat e th e impact s o f historical smeltin g operation s o n huma n healt h an d th e environment

. T o accomplis h thi s goal , physica l an d chemica l soi l dat a collecte d durin g thi s investigatio n an d fro m previou s soi l samplin g event s wer e compile d an d interpreted

. Thi s informatio n wa s use d t o evaluat e th e impact s o f smelte r operation s o n soil s an d t o characterize th e geographi c distributio n o f soi l metal s originatin g fro m histori c smelte r facilities

. A n ai r dispersio n mode l wa s use d t o evaluat e depositiona l pattern s o f smelte r emission s an d t o identif y potentia l area s o f maximu m metal s concentration s resultin g fro m smelte r emissions

. Soil s withi n thes e area s predicte d t o hav e maximu m metal s concentration s wer e the n targete d t o b e sampled

. I n addition , th e literatur e an d histori c record s pertainin g t o histori c smelte r desig n an d operation s wa s reviewed

. Thi s informatio n wa s use d t o conduc t a fiel d reconnaissanc e an d t o identif y th e location s o f histori c smelte r facilities

. Th e fiel d 

### reconnaissanc e confirme d th e location s o f th e histori c smelte r sites , identifie d buildin g debri s o r evidenc e o f forme r structures , identifie d area s wher e ba g hous e an d flu e dus t wast e ma y hav e bee n managed , an d locate d disposa l area s for smelte r slag

. Th e soil s dat a use d i n th e Smelte r Investigatio n wer e take n fro m th e CD M Soils Investigation Data Report (1993 ) an d fro m 7 7 samples collecte d i n area s identifie d b y th e ai r dispersio n model

. Th e CD M soil s investigatio n wa s conducte d i n 199 1 an d 199 2 a t whic h tim e 71 9 soi l sample s wer e collected

. Al l sample s wer e analyze d b y energ y dispersiv e X-ra y fluorescenc e (EDXRF ) fo r meta l contaminant s o f concer n includin g lead

. Th e samplin g locations , th e Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

. 4800-37-020 5 Interi

m Statu s Repor t Pag e A-4 7 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

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. epa\soils-ri\append-a.ju n

### ^ samplin g methodology , th e analytical method , an d th e analytica l dat a pertainin g t o th e CD M 

### Soil s Investigatio n ar e describe d i n Sectio n A.3.5

. «^ i A.3.7. 1

Ai r Dispersio n Modelin g » — T h e DSTCS T mode l o f th e EPA' s UNAMA P serie s wa s use d t o predic t depositio n o f smelte r



### — emission

s o n soil s a t th e Californi a Gulc h Site

. Th e parameter s inpu t t o th e mode l ar e (1 ) locatio n an d elevatio n o f eac h smelter , (2 ) date s o f operatio n (emission s star t an d en d dates , ^ lengt h o f operation) , (3 ) type s an d numbe r o f stacks , (4 ) stac k height s an d inne r diameters , (5 ) 

### exhaus t ga s temperature s an d velocities , (6 ) meta l concentration i n exhaus t (relate d t o productio n


### -» rate) , an d (7 ) particl e siz e distributions fo r smelte r emissions

. Attempt s wer e mad e t o obtai n actua l dat a specifi c t o eac h smelte r fo r eac h paramete r o f interest

. The meteorologica l 

### *•* • informatio n collecte d fro m th e Colorad o Mountai n Colleg e monitorin g statio n wa s use d for th e depositio n modelin g wit h th e INCS T model

. 

### Metal concentration s wer e compute d assumin g tha t th e smelte r emissio n ove r th e lif e tun e o f th e
v 

### smelte r occurre d i n on e yea r an d tha t al l metal s deposite d a t a particula r locatio n ar e mixe d int o th e soi l t o a dept h o f 2 0 centimeter s becaus e o f ris k assessmen t considerations

.

- \, w A.3.7. 2

Smelte r Soil Samplin g

— v 

### Seve n forme r smelte r site s wer e selecte d fo r soi l samplin g fo r assessmen t o f meta l concentrations , includin g lead , an d for identificatio n o f minin g relate d material s i n soi l sampl e 

### pit s t o a dept h o f a t leas t 1 8 inches

. Th e soil s wer e sample d a t th e sam e dept h interval s an d

-v > 

### usin g th e sam e procedure s a s thos e describe d i n th e CD M Soils Investigation Data Report (1993)

. Th e seve n smelte r site s include : th e Arkansa s Valley/America n Smelte r site ; th e L a 

### Plat a Smelter/Bi-Metalli c Smelte r site ; th e Wester n Zin c Smelter ; th e Grant/Unio n smelte r site ; th e Harriso n Reductio n Work s site ; th e Elgi n Smelter/Bosto n Gold-Coppe r Smelte r site ; an d th e grou p o f forme r smelter s i n th e uppe r Evan s Gulch

. Th e sample s wer e collecte d o n th e CD M grid

. Discret e smelte r sample s wer e collecte d fro m area s wher e histori c smelte r baghouses , dus t


### ^ chambers,

o r roastin g furnace s wer e located

. Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

. 4800-37-020 5 Interi

m Statu s Repor t Pag e A-4 8 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

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. epa\soils-ri\append-a.ju n

### I n additio n t o th e CD M soi l samplin g dat a (CDM
, 1993) , 7 7 additiona l soi l samples wer e take n i n suppor t o f th e Smelte r Remedia l Investigation

. Thes e procedure s ar e describe d i n Section s A.3.5.1 , A.3.5.2 , an d A.3.5. 3 o f thi s report

. Seventy-on e o f th e 7 7 soi l sampl e locations , 

### base d o n dispersio n modelling , wer e determine d b y the ISCS T ai r dispersio n model

. Al l excep t fo r thre e locations , base d o n dispersio n modeling , wer e sampled

. Acces s wa s denie d t o thre e locations

. Th e sample d location s wer e lai d ou t o n a 700-foo t gri d i n accordanc e wit h ASARCO' s lette r t o K

. Wangerud , date d 2 8 Octobe r 199 1 (ASARCO
, 1991)

. Th e soi l samplin g 

### location s wer e positione d o n th e 1,000-foot gri d oriente d N 45 W

. Th e categorie s o f soi l samplin g an d th e samplin g location s ar e describe d i n Sectio n A.3.5.1

. Th e soi l sample s wer e 

### collecte d fro m th e Arkansa s Valley , th e Wester n Zinc , and th e Elgi n smelte r site s i n th e vicinit y o f histori c ba g houses , dust chambers , o r wast e pile s identifie d fro m th e literatur e an d smelte r reconnaissance

. 

### A.3.7. 3 Area s Impacte d b y Smelte r Emission s A combinatio n o f graphica l an d statistica l procedure s wer e employe d t o identif y soi l sampl e site s tha t wer e likel y impacte d b y historical smelte r emissions

. Al l soi l sampl e location s a t th e sit e 

### wer e classifie d a s either disturbe d (containin g visibl e min e waste , sla g fil l material , and/o r 

### huma n artifacts ) o r undisturbe d (lackin g visibl e min e waste , fil l material , and/o r huma n 

### artifacts)

. Th e presenc e o r absenc e o f thes e material s wa s use d t o assis t i n th e identificatio n o f sampl e location s a s area s impacte d primaril y b y smelte r emissions

. I f an y o f thes e material s 

### wer e observe d a s bein g presen t i n on e o r mor e samplin g intervals , th e locatio n wa s classifie d
a s disturbed

. 

### T o assist i n delineatin g th e area l exten t o f smelte r emissio n impacts , th e Sit e wa s divide d int o eigh t geographi c areas . Thes e area s wer e define d o n th e basi s o f soi l typ e (disturbe d versu s undisturbed) , populated , and unpopulated

. The area , immediatel y sout h o f the forme r A V 

### smelter , wa s use d a s th e contro l area . Th e contro l are a consist s o f predominantl y nativ e undisturbe d soils , s o an y impact s woul d mos t likel y b e th e resul t o f smelte r emissions

. Th e 

### area s tha t fal l withi n th e Residentia l Soil s Stud y Are a includ e th e Nort h Leadville
, th e Eas t 

### Leadville
, an d th e Wes t Leadville

. Turquois e Lak e Estate s fall s withi n th e Northwes t Stud y Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 1996 Documen t Contro l No

. 4800-37-020 5 Interi

m Statu s Repor t Pag e A-4 9 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

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. epa\soils-ri\append-a.ju n

### Area , and the Lak e Fork Traile r Par k i s locate d withi n the Lowe r Californi a Gulch-Malt a Gulc h Area

. * ? 

### Meta l pai r ratio s havin g significan t (9 9 percen t leve l o f confidence ) correlate d concentration s • ^ wer e identifie d i n th e contro l are a an d wer e use d t o establis h a meta l signatur e fo r soil s impacte d primaril y wit h smelte r emissions

. Onl y undisturbe d sample s i n th e contro l are a wer e use d a s 

### ^

- contro l sample s (sample s representin g soi l impacte d exclusivel y b y histori c smelte r emissions)

. Ther e ar e nin e meta l combination s (ratios ) tha t hav e significan t correlation s i n th e contro l are a " ? an d includ e th e following : Pb:Zn
, Pb:Fe
, PbrCu
, ZnrFe , Zn:Ca
, Fe:Cu
, FerCa
, an d Fe:Ba

. Thes e meta l ratio s wer e the n compared t o th e sam e meta l ratio s foun d i n th e 0

- t o 1-inc h an d



### ^ 1

- t o 2-inc h dept h interval s o f disturbe d an d undisturbe d soil s throughout th e stud y area . Thos e soil s i n th e stud y are a exhibitin g metal s ratio s simila r t o th e ratio s foun d i n soil s fro m th e contro l


### are a wer e considere d t o hav e bee n impacte d b y smelte r emissions

. A 750-foo t buffe r zon e wa s 

### draw n aroun d al l sampl e site s exhibitin g a smelte r signatur e fo r a t least seve n ou t o f th e nin e

~ " meta l combinations

. Thi s zon e establishe d a boundar y aroun d area s identifie d t o b e impacte d b y smelte r emissions

. y A.3.7. 4 Result s ••.«* • 

### Meta l concentration s o f soi l sample s collecte d fro m th e forme r smelte r site s are show n i n Tabl e s * A-ll

. Th e meta l concentrations , includin g lead , d o no t decrease wit h increasin g dept h a s the y 

### d o i n mos t soil s sample d withi n th e Californi a Gulc h Site

. I n general , soil s a t th e forme r ^ > 

### smelte r site s exhibi t significan t meta l concentration s tha t occurre d ove r th e lifetim e o f th e smelters operations

. *** 

### Th e environmenta l impacts , vi a th e ai r pathwa y du e t o pas t smelte r activities , occurre d a s a V 

### resul t o f th e depositio n o f airborn e particulate s and gaseou s smelte r emission s followe d b y thei r subsequen t redistributio n t o othe r soils , t o vegetation , an d t o surfac e water

. Th e processe s tha t contribute d t o thi s redistributio n includ e th e following :
Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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. epa\soils-ri\append-a.ju nTabl e A-l l Averag e Meta l Concentration s at Forme r Smelte r Site s

0

- 1 1 - 2 2 - 6 6-1 2 12-1 8 

### illlilliiillll l 

## Itiiiii^iiiii i 6,76 9 8,13 1 4,00 1 3,09 9 92 8 ;ii:^l®pt^iPi

i 5,74 7 4,33 4 1,73 2 1,29 0 71 2 §*?S:i:?M|j^iiliiiiii

: : : ; : : : : : : : ; : ; :-: : :::-: : ::::X:::<*a::::v:

: ::::: : ::: : : : :v:::;:: : : 

## PipS^siiiii i 66 5 61 5 53 5 35 4 5 1 

### lllllliiBli i liiiiiiiiiiili i 221 17 6 4 9 5 2 1 2 

## lilliillill i lliyilasp^iil i 2 0 2 0 2 0 2 0 1 5 l;^;::; ^ ^•^i-^IjiS^lWi i 

## p^^fci^ f
0

- 1 1 - 2 2 - 6 6

- 1 2 12

- 1 8 

## WMJmiis mmift^§mm 6,38 0 6,61 5 6,69 3 8,74 9 6,56 9 

## lllllllillllll l iili-fiii^llli i 3,26 8 2,81 3 3,87 9 3,645 3,600 

# Illlllillltllfl i lillliS^pSiillllll l 46 5 46 1 52 1 91 3 1,07 5 •

. • S : : : : : ;

- • - : : : M^^:iml::XiSim^^^^^^li^^i^^^^&^ ^^^3$$; :::;^' : 'j:'V'i@ni):n---^

- ::: 1 0

- 1 1 - 2 2 - 6 6

- 1 2 12

- 1 8 

# liiiiiiiiii i mw^i^^iifim 99 9 89 9 56 5 38 5 37 6 ITOJ:;;S;li^.i;e;S;:; : ; : J

16,70 0 13,16 1 6,82 6 2,76 4 69 7 

# liiiiiiiiiiili i iilliiliPiiillll l 26 2 13 9 5 3 3 8 4 

## lll^ll^lHIfsll l til:ip:|#ll;|:|:;:::::; l 11 0 2 2 1 6 1 5 1 6 IlllliiliillP

i 

## m^^j^mmi: 4 4 4 4 4 IlllPlilii^liii l 3 2 4 3 3 9 3 0 4 

# Illllililill l K|i|l;iSiniiyfeig;iii ; 7 7 7 7 5

; : ..".:

. /•-. : ;..:; . -..:• : - : xi : : l^illiliS

^ :^: : :.::{:••::

. Depth,;- : •; : H i ^;;H ; ! : »^:i ; : l 0

- 1 1 - 2 2 - 6 6-1 2 12

- 1 8 !:&;;;i:l::-;;^li|lif

i P : i i ; ilK^iil ^ 2,22 5 2,12 2 2,30 1 2,39 7 2,25 2 :^!:x^fe-:-:::: : s;;l;:-:::> : : :>:x>- : ^ :' ^ s^fmvtti&itmmtSffti
56 3 56 4 65 4 90 6 82 8 lii::;i:;:i;?;:;^;lPili;: S

:;:¥::::::•:::•:,::;:::•;:«*»:¥:::: :

:'::::.:::v:::::. K | i : :;P:^lSi^iStllII I 1 4 2 1 4 0 2 5 2 4 

## lillllliillll l iillliiiiiilllP l 0 3 2 7 6 ll||;:||l||l|l

| ||;|ijSSii((ii^iji i 2 2 2 2 2 Residential-Populate d

Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

. 4800-37-020 5 Interi

m Statu s Repor t Pag e A-5 1 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

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. epa\soils-ri\append-a.ju n

### Tabl e A-l l (continued ) Averag e Metal Concentration s at Forme r Smelte r Site s 

## 111!!!!! ^ 

# lllliiiiiliili i ifiiiitiii^iPi i 0

- 1 1- 2 2 - 6 6-1 2 

# llllillllll^ll l IPII ; 

### li§iiiilill l 3,72 4 4,59 9 5,01 9 4,33 5 2,92 6 

### ||l|l||||l|l|| | ili;i:llsii!®P^;S?*;;:l;S M 5,34 6 6,00 3 5,56 3 3,32 0 1,87 3 :^::::::i^:;^:::^: : ::^!^:::^:::^:::^:^:::^i: : 

## llllliiiiililil l 18 6 16 9 18 5 28 2 15 5 !iiliip|i!!p!! : j
3 2 4 2 2 7 1 6 9 Illlllllllli l Ilii^^m^pisils f ; : ; ; 3 3 3 3 3 

# liiisiiiiiM litlliiliililtll l

0

- 1 1 - 2 2 - 6 6-1 2 12

- 1 8 

### llfitlfipilllfl l 8,52 0 5,53 6 3,83 1 5,436 13 9 

### lilllliiilll^ll l i?PP^»lfci?i i 5,07 3 3,29 4 2,51 1 3,03 9 47 5 

# illlllllllli l Iliil^diji;|;:s:::::g::;: : 30 7 25 2 16 0 25 9 0 :S?:5:jSS;?SiS:^SKi:JTM::;:;i;:; : ; : S m&mrniyfaxmxm IllPliSiiii^illl:;:; : 3 1 1 5 1 2 1 7 1 

# ^l:iiliiill^ill l S^Sm^^S'-A 3 3 3 3 2 

### i ; 

### iCii£: 

### ;:JilJ|| ^ 

## liM^pi M 

# m^<mmm 0 - 1 1 - 2 2 - 6 6

- 1 2 12

- 1 8 

## l:|;;l|lltltfllll l IW:ti- : 

### iS*iBWSf l 3,15 9 2,46 9 3,85 9 7,48 7 1,78 0 

# itiiiiiliiiiiit i liillllllpiiPil i 1,71 2 1,81 1 1,60 0 1,02 6 49 8 

### iiiiislliliii i 

### iiftiipi^iiiii l 0 0 7 2 4 1 4 

### mfmm^ifmiim

7 7 6 8 0 

# iillfii^iiiii i m^fMiJaiiiaiJ^mm 3 3 3 3 3
in

. = m m = pp m = inc h millimete r part s pe r millio n

Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

. 4800-37-020 5 Interi

m Statu s Repor t Pag e A-5 2 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

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. epa\soils-ri\append-a.ju n

### •

Th e effec t o f win d erosio n an d th e subsequen t airborn e transpor t o f resuspende d paniculat e contaminate d wit h lea d an d othe r metals

. • Th e chemica l transformatio n o f smelte r emissio n containe d i n impacte d soil s b y th e actio n o f thiobacillus an d metallogeniu m organism s an d b y th e actio n o f acidi c surfac e water s resultin g i n a n increase d mobilit y o f ne w chemica l species

. • Th e accumulatio n o f lea d an d othe r metal s i n th e organi c fractio n o f soil s an d subsequen t uptak e b y vegetation

. • Th e remova l o f surfac e soil s impacte d b y smelte r emission s an d th e mixin g o f impacte d surfac e soil s wit h constructio n fil l du e t o lan d development , lan d contouring , an d relate d activities

. Th e ai r dispersio n modelin g predicte d th e contributio n o f metal s o f concern , includin g lead , fro m histori c smelte r emission s t o th e soil s o f th e stud y area . Th e stud y area s tha t wer e predicte d t o b e impacte d b y smelte r emission s includ e th e Stringtow n are a an d th e entir e souther n hal f o f Leadville

. Th e modelin g tas k combine d th e metal s o f concer n i n it s projectio n an d reporte d a 

### maximu m o f 2,75 0 t o 3,00 0 mg/k g a t a dept h o f 0 t o 2 0 c m i n th e Stringtow n area . I t predicte d tota l metal s concentrations , i n th e souther n hal f o f Leadville
, t o rang e fro m 1,20 0 t o 2,25 0 

### mg/k g a t a dept h o f 0 t o 2 0 cm . T o validat e th e predicte d impact s fro m histori c smelte r emissions , measure d value s o f th e sam e metal s fro m sampl e location s withi n th e stud y are a wer e 

### composite d an d compared t o th e predicte d values

. Th e tw o dat a set s wer e analyze d bot h statisticall y an d graphically

. Statistica l analysi s entaile d regression analysi s t o detect an y linea r correlatio n betwee n predicte d an d actua l values

. A Kruskall-Walli s Ran k Su m tes t wa s als o use d 

### t o compare th e tw o dat a sets

. Ther e appear s t o b e littl e agreemen t betwee n th e predicte d an d actua l value s ove r mos t o f th e stud y area . Meta l concentrations , includin g lead , i n disturbe d an d undisturbe d soil s wer e observe d t o decreas e wit h soi l dept h (excep t a t forme r smelte r sites)

. Th e concentration s o f lea d i n disturbe d 

### soil s a t al l soi l dept h interval s ar e higher tha n thos e foun d i n th e sam e dept h interval s o f undisturbe d soils

. Th e mea n meta l concentration s i n disturbe d an d undisturbe d les s tha n 2 m m soil s ar e summarized i n Tabl e A-12

.
Residential-Populate d

Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

. 4800-37-020 5 Interi

m Statu s Repor t Pag e A-5 3 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

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. epa\soils-ri\append-a.ju n

### Tabl e A-1 2 Mea n Metal s Concentration s b y Dept h Interva l fo r < 2 m m Soil s Dat a fo r Disturbe d an d Undisturbe d Sampl e Site s Dept h (inches ) 0- 1
1- 2
2- 6
6-1 2
12-1 8 Disturbed

? Y e s N o Y e s N o Y e s N o Yes N o Y e s N o Mea n Concentratio n A s (ppm ) (n ) 12 8 (443 ) 115 (347 ) 12 3 (442 ) 7 0 (347 ) 7 9 (443 ) 2 6 (347 ) 5 8 (444 ) 1 7 (346 ) 3 7 (415 ) 1 3 (299 ) C d (ppm ) (n ) 2 6 (443 ) 1 3 (347 ) 2 3 (442 ) 8 (347 ) 1 3 (443 ) 4 (347 ) 1 1 (444 ) 2 (346 ) 8 (415

) 1 (299 ) P b (ppm ) (n ) 2,73 4 (442

) 2,07 5 (347

) 2,54 5 (442

) 92 5 (347

) 2,06 3 (443

) 29 3 (347

) 1,69 6 (444

) 11 0 (346

) 1,45 6 (415

) 9 9 (299

) Z n (ppm ) (n ) 3,29 1 (443

) 70 4 (347

) 2,86 6 (442

) 49 2 (347

) 2,08 8 (443

) 27 7 (347

) 1,52 9 (444

) 13 1 (346

) 1,23 9 (415

) 12 0 (299

)

n = numbe r o f case s constitutin g tha t particula r averag e pp m = part s pe r millio n

Residential-Populate d

Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

. 4800-37-020 5 Interi

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. epa\soils-ri\append-a.ju n

### Area s foun d t o exhibi t th e smelte r emissio n signatur e include : th e are a sout h o f Californi a Gulch


### an d downwin d o f th e forme r Arkansa s Valley , California
, L a Plata
, an d America n smelter s (essentiall y th e contro l area) ; th e wes t an d northwest section s o f th e stud y area ; an d portion s o f Evan s Gulch tha t correspon d t o th e forme r smelte r site s alon g th e gulch , an d a smal l are a nea r th e forme r Littl e Chie f Smelter

. Th e contro l are a i s considere d t o b e a prim e exampl e o f a n undisturbe d are a tha t ha s bee n 

### impacte d primaril y b y smelte r emissions

. Ther e ar e n o sign s o f historica l minin g activit y her e an d th e are a ha s no t bee n use d a s a dumpin g sit e fo r slag , tailings , o r othe r min e waste

. Area s determine d t o b e impacte d predominantl y wit h source s othe r tha n smelte r emission s include : Leadvill e prope r consistin g mostl y o f variou s type s o f fil l material ; th e eas t stud y are a 

### (include s th e area s eas t an d sout h o f Leadville ) consistin g mostl y o f alluvia l tailing s an d min e wast e rock ; Californi a an d Malt a Gulches whic h contai n mostl y alluvia l tailing s an d min e wast e rock ; th e Hecl a tailing s area ; Lak e Fork Traile r Par k whic h consist s mostl y o f fil l material ; an d channel s an d lo w terrace s o f th e Arkansa s Rive r whic h ar e impacte d b y fluvia l tailings

. 

### The geographi c area s o f Wes t Leadvill e and Nort h Leadvill e contai n a n averag e o f 1,53 4 pp m P b an d 89 8 pp m P b i n th e 0 t o 1 inc h interval , respectively

. Mos t o f th e 0 t o 1 inc h soi l sample s i n thes e area s ar e impacte d b y source s othe r tha n smelte r emission s ye t 1 1 percen t o f th e site s exhibi t a smelte r signature

. Thi s indicate s tha t bot h smelte r emission s an d othe r source s 

### hav e impacte d soi l meta l concentration s i n thes e areas . Th e remainde r o f th e Residential Soil s Stud y are a containe d n o site s wit h significan t meta l 

### signature s resemblin g th e contro l sites

. This doe s no t exclud e smelte r emission s a s a sourc e o f impac t i n thes e areas . Th e fac t tha t smelte r impacte d soil s surroun d Leadvill e prope r o n th e 

### west , north , an d sout h suggest s tha t Leadvill e prope r ha s ha d som e impac t fro m smelte r 

### emissions

. However , thi s stud y demonstrate s tha t othe r source s ar e th e predominat e sourc e o f impac t t o Leadvill e proper

.
Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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. epa\soils-ri\append-a.ju n

### Th e area s impacte d predominantl y wit h smelte r emission s contai n 27 6 undisturbe d soi l sampl e sites

. Averag e meta l concentration s o f thes e 27 6 samples b y sampl e interva l ar e show n i n Tabl e A-13

. Lea d concentration s i n th e undisturbe d area s impacte d predominantl y wit h smelte r 

### emission s dro p of f dramaticall y fro m th e 0 t o 1 inc h sampl e interva l (averag e 1,89 5 pp m Pb ) t o th e 1 t o 2 inc h interva l (averag e 79 2 pp m Pb ) an d t o th e 2 t o 6 inc h interva l (averag e 17 4 pp m Pb)

. Th e othe r thre e metal s o f concer n display a simila r decrease wit h depth

. This 

### demonstrate s tha t undisturbe d area s impacte d predominantl y wit h smelte r emissions , i n general , contai n elevate d meta l concentration s i n th e uppe r tw o inches, an d belo w tw o inche s meta l concentration s decrease dramatically

. 

### Withi n the Californi a Gulc h Sit e the area s wit h the highes t lea d concentration s wer e foun d t o correspon d t o eithe r gentl y slopin g topographic high s o r gentl y slopin g tree-covere d topographic 

### highs

. Thes e hig h lea d concentration s wer e foun d i n th e 0

- t o 1-inc h soi l sampl e increment

. A prim e exampl e o f suc h a gentl y slopin g topograph y wit h a lea d concentratio n i n exces s o f 5,000 mg/k g i s locate d betwee n wester n Leadvill e an d th e Turquois e Lak e Estates

. Thes e 

### elevate d area s ar e pron e t o erosio n an d ca n impac t th e Residentia l Stud y Area

. Thi s exampl e are a t o th e wes t o f Leadvill e an d othe r simila r area s ar e al l locate d outsid e o f th e Residentia l Stud y Area

. Area s o f lo w lea d concentrations , i n th e 0

- t o 1-inc h soi l sampl e increment , ar e 

### foun d o n mor e strongl y slopin g topographi c area s tha t ar e devoi d o f vegetativ e cover . Th e surfac e soil s o f strongl y slope d area s are mor e pron e t o erosio n durin g period s o f stron g surfac e wate r runoff

. Thi s proces s no t onl y remove s soil s contaminate d wit h smelte r emissio n bu t ca n 

### resul t i n th e transpor t o f lea d contaminate d soil s an d paniculat e ont o th e Residentia l Stud y Are a an d int o surfac e wate r features

. Win d erosio n result s i n th e resuspensio n o f soils , smelte r emission s paniculate , an d lea d 

### containin g minin g waste s a t the Californi a Gulc h Sit e and the Residentia l Stud y Area

. Win d erosio n represent s a n airborn e transpor t an d redistributio n process

. Thi s proces s i s multi



### directiona l an d i s drive n b y th e prevailin g meteorologica l conditions

. This proces s i s mos t effectiv e durin g lat e fal l an d sprin g whe n soil s are dry

. Win d erosio n i s also affecte d b y soi l textur e an d th e quantit y an d typ e o f vegetativ e cove r tha t i s presen t i n th e area . Residential-Populate d

Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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m Statu s Repor t Pag e A-56 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

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. epa\soils-ri\append-a.ju n

### Tabl e A-1 3 Averag e Concentration s o f Pb
, Zn, A s an d C d fo r Area s Impacte d Predominantl y b y Smelte r Emission s 

# IIIBIII I ilitl$l^ll l lilflilllll l 

# flilfllllll l lilllillli l S:; : i|Si;:iijp;|;g5:;:s;;i S ;:;:::S:::S:;:;:ili*5|*

: 5s:;:;:;-;:s:: : 1,86 9 75 1 17 3 7 5 6 7 KiSiijSj^HjiSifHg: ; 

# lllilill l 46 6 30 0 16 8 11 6 11 2 

### isliiill l mxm^mm
12 3 7 4 2 5 1 8 1 3 1 3 8 4 2 1

Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

. 4800-37-020 5 Interi

m Statu s Repor t Pag e A-5 7 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

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. epa\soils-ri\append-a.ju n

### Th e stronges t wind s o n a n annua l basi s tha t ca n resul t i n th e erosio n o f soil s cam e fro m th e southwest throug h west-southwes t wit h velocitie s o f 1 8 t o 2 4 mph

. Th e mos t persisten t win d direction s o n a n annua l basis , fo r th e period o f Octobe r 199 0 t o Octobe r 1991 , wer e fro m th e 

### northwes t throug h th e northeas t an d th e northeas t throug h th e eas t (Woodward-Clyd e Consultant s [WCC]
, 1992a)

. Thi s suggest s tha t historically , soil s impacte d b y smelte r emission s fro m th e American , Arkansa s Valley , California
, Wester n Zinc , an d Leadvill e smelter s wer e subjec t t o win d erosion

. A persisten t win d directio n fro m th e west-southwes t suggest s tha t win d erosio n playe d a rol e i n redepositio n o f thes e smelte r emission s i n th e communitie s o f Stringtow n an d 

### Leadville

. Soil s containin g lea d i n exces s o f 3,50 0 mg/k g (Walsh , 1993 ) locate d i n th e Stringtow n communit y represen t a significan t potentia l fo r airborn e transpor t o f thes e material s t o Leadvill e whe n th e prevailin g wind s are fro m th e west-southwest

. A.3. 8 Surfac e Wate r Remedia l Investigatio n Repor t (WCC

. 1993c ) 

### Th e Surface Water Remedial Investigation Report i s a n elemen t o f th e Phas e n R I o f th e Californi a Gulc h CERCL A site

. Thi s repor t describe s th e investigatio n o f severa l surfac e wate r 

### drainage s locate d withi n and nea r the Residentia l Stud y Area

. The fiel d investigation s wer e performe d durin g th e 199 1 Ice-of f event , th e 199 1 Sprin g Runoff
, th e 199 1 Summer
, th e 199 1 

### Summe r Storms
, th e 199 1 Fall , an d durin g th e Winte r o f 1992

. Th e wor k wa s performe d i n accordanc e wit h Th e Surface Water, Be d Material an d Aquatic Ecosystem Data Collection Program Work Plan (WCC
, 1991d)

. Th e firs t objectiv e o f th e surfac e wate r dat a collectio n syste m wa s t o evaluat e th e physica l and chemica l characteristic s o f th e surfac e wate r associate d wit h th e Californi a Gulch site

. Thi s 

### include d a n evaluatio n o f th e subdrainage s withi n th e Californi a Gulc h i n orde r t o identif y significan t contributor s t o contamination loadin g i n th e Gulch ; an d t o evaluat e th e seasona l 

### variation s i n wate r flo w an d contaminan t loading

. This characterizatio n includes strea m flo w measurement s an d strea m surfac e wate r an d be d materia l samplin g an d analysis

. Th e dat a fro m thi s monitorin g an d samplin g progra m wil l als o b e use d t o evaluat e th e fiel d progra m i n term s 

### o f identifyin g ne w location s o f samplin g an d flo w measurin g station s an d th e relocatio n o r Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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. epa\soils-ri\append-a.ju n

### eliminatio n

o f existin g stations

. Th e secon d objectiv e involve s th e evaluatio n o f th e aquati c ecosyste m t o determine th e natur e an d exten t o f contamination o f thi s ecosystem

. Thi s 

### evaluatio n includes toxicit y assessment s o f surfac e water s usin g standar d bioassay s o f th e wate r fle a an d th e fathea d minnow , analyse s o f benthi c macroinvertebrates ,

an d qualitativ e analyse s o f periphyton

. A.3.8. 1 Surfac e Wate r Flo w Monitorin g an d Sampl e Collectio n Syste m Location s 

### The surfac e wate r monitorin g an d sampl e collectio n syste m use d fixe d samplin g an d gagin g station s withi n the watersheds

. The station s wer e locate d wher e a permanen t flo w measurin g device (flume ) o r permanentl y installe d staf f gage s existe d o r wer e subsequentl y installed

. Th e 

### fiel d investigatio n are a wa s divide d int o th e followin g watersheds : Star r Ditc h an d Stray Hors e 

### Gulch
, Eas t For k o f the Arkansa s River
, the Evan s Gulc h and tributaries , the Halfmoo n Cree k th e Tennesse e Creek
, and Lak e For k Creek

. Thirtee n samplin g station s wer e locate d withi n 

### Californi a Gulc h an d tributaries

. Tw o samplin g location s wer e locate d o n th e Star r Ditc h an d Stra y Hors e Gulch

. Tw o samplin g station s wer e locate d alon g th e Eas t Fork o f th e Arkansa s River

. Thre e station s wer e locate d alon g th e Evan s Gulc h an d th e Littl e Evan s Gulch

. On e statio n wa s locate d alon g th e Tennesse e Cree k an d on e alon g th e Iow a Gulch

. On e statio n wa s locate d alon g Halfmoo n Cree k and one alon g th e Lak e Fork Creek

. Fou r samplin g station s wer e locate d alon g th e Empir e Gulch

. Si x station s wer e locate d alon g th e Arkansa s River

. A.3.8. 2 Surfac e Wate r an d Be d Materia l Samplin g 

### Surfac e wate r sample s wer e collecte d wit h a beake r an d place d int o a chur n splitte r durin g al l


### o f th e samplin g event s excep t fo r th e 199 1 Summe r Storm s event

. Sample s wer e distribute d 

### fro m th e chu m splitte r t o samplin g bottles

. Durin g th e 199 1 Summe r Storm s samplin g program , automati c samplin g equipmen t wa s installe d at station s AR3A
, ARSE
, AR02
, an d CG06

. Thre e storm event s (occurrin g o n 2 4 August , 3 0 August , an d 1 1 Septembe r 1991 ) wer e sample d usin g 

### th e automati c samplin g equipment

. Surfac e wate r sample s t o b e analyzed fo r alkalinity , Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

. 4800-37-020 5 Interi

m Statu s Repor t Pag e A-5 9 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

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. epa\soils-ri\append-a.ju n

### chloride ,

fluoride , an d dissolve d metal s wer e filtere d usin g a 0.4 5 /x m membran e filte r an d 

### peristalti c pump

. Sample s tha t wer e analyze d fo r tota l metal s wer e no t filtered

. Be d materia l wa s sample d usin g a stainles s stee l scoop

. A composit e be d materia l sampl e wa s obtaine d b y collectin g be d materia l fro m acros s th e entir e widt h o f th e strea m be d an d mixin g 

### th e sample d material s i n stainles s stee l bowl

. Be d materia l samples wer e take n fro m th e sam e 

### location s afte r th e surfac e wate r sample s A.3.8. 3 Analysi s o f Surfac e Wate r an d Bed Materia l Surfac e wate r sample s an d bed materia l samples wer e analyzed fo r th e analyte s liste d i n Table s A-1 4 an d A-15 , respectively

. Thes e table s also identif y th e analytica l method s use d fo r 

### eac h analyt e an d th e metho d detectio n limits

. A.3.8. 4 Natur e an d Exten t o f Contaminatio n Base d o n th e analytica l dat a fo r surfac e wate r an d be d material , an d statio n flo w dat a fo r al l o f 

### th e samplin g station s an d samplin g events , th e followin g characterization s wer e made : Durin g al l samplin g events , th e Californi a Gulch drainag e exhibit s elevate d concentration s an d load s o f aluminum , arsenic , barium , cadmium , copper , iron , 

### lead , manganese , mercury , nickel , silver , an d zin c i n surfac e wate r compare d t o 

### thos e i n othe r tributarie s o f th e Arkansa s River

. Concentration s o f aluminum , arsenic , cadmium, copper , iron , lead , manganese, an d zin c i n th e Arkansa s Rive r surfac e wate r downstrea m o f th e confluenc e wit h Californi a Gulch ar e greate r tha n concentration s i n th e Arkansa s Rive r upstrea m 

### o f th e Californi a Gulc h confluenc e durin g certai n time s o f th e year . 

### Metal s a t th e Californi a Gulc h sit e ma y originat e fro m severa l potentia l sources , an d includ e th e following :


### • Surfac e wate r runof f fro m wast e roc k piles , sla g piles , smelte r sites , tailing s 

### impoundments , an d othe r mineralized-fil l areas . Residential-Populate d

Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

. 4800-37-020 5 Interi

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. epa\soils-ri\append-a.ju n

### Tabl e A-1 4 

### Surfac e Wate r Sample s - Parameter s Analyzed , Analytica l Method s an d Detectio n Limit s Paramete r Fiel d Analysis p H Specifi c conductivit y (SC ) Dissolve d Oxyge n (DO ) Alkalinity * Chlorine * Laborator y Analysi s P H b Specifi c conductivit y (SC) b Tota l suspende d solid s (TSS) b Tota l dissolve d solid s (TDS) b Dissolve d Organi c Carbo n (DOC) b Alkalinity d Calciu m (Ca) d > e Magnesiu m (Mg) d e Sodiu m (Na) d > e Potassiu m (K) d > e Chlorid e (Cl) b > d Sulfat e (SO 4 ) b d Silic a (SiO2) b d Tota l phosphorus

b ) d Fluorid e (F) b d Nitrat e + Nitrite b ) d Cyanid e Metal s (Tota l an d Dissolved ) Aluminu m (Al) e Antimon y (Sb) e Arseni c (As) e EP

A Metho d N / A N / A N / A N / A N / A
150. 1 120. 1 160. 2 160. 1 ASTM D 4129-8 2 310. 1 200. 7 CLP- M 200. 7 CLP- M 200. 7 CLP- M 200. 7 CLP- M 325. 3 375. 4 200. 7 365. 1 340. 2 353. 2 335. 3 CLP- M
200. 7 CLP- M 200. 7 CLP- M 206. 2 CLP- M CRD

L

N / A N / A N / A N / A 5 5 5 5 N / A N / A N / A N / A N / A N / A 1 0
20 0 6 0 1 0 I D

L

2 C 2 C 1 l c 1 1 1 1 l c 4 C l c 0.01 C O.l c 0.02 C 1 0
5 0 4 0 1 Reportin

g Unit s
/tmhos/c m mg/ l mg/t mg/ f
^mhos/cm mg/ £ mg/ £ mg/t mg/ f mg/t mg/t mg/f mg/t 

### mg/t mg/t mg/t mg/t mg/t mg/t mg/t Mg/ f Mg/ f Mg/ f Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Documen t Control No

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. epa\soils-ri\append-a.ju n Jun e 199 6 Pag e A-6 1 I T SHAL L NO T B E RELEASE D O R DISCLOSE D I NTabl e A-14 (Continued ) 

### Surfac e Wate r Sample s - Parameter s Analyzed , Analytica l Method s an d Detectio n Limit s Paramete r Bariu m (Ba) e Cadmiu m (Cd) e Chromium (Cr) e Coppe r (Cu) e Iro n (Fe) e Lea d (Pb) e Manganes e (Mn) e Mercur y (Hg) e Nicke l (Ni) e Seleniu m (Se) e Silve r (Ag) e Zin c (Zn) e EP

A Metho d 200. 7 CLP- M 200. 7 CLP- M 200. 7 CLP- M 200. 7 CLP- M 200. 7 CLP- M 239. 2 CLP- M 200. 7 CLP- M 245. 2 CLP- M 200. 7 CLP- M 270. 2 CLP- M 200. 7 CLP- M 200. 7 CLP- M CRD

L 20 0 5 (0.1) f 1 0 2 5 (l) f 10 0 3 1 5 0. 2 4 0 5 10(0.1) f 2 0 ID

L 1 0 0. 1 1 0 1 2 0 1. 1 1 0 0. 2 2 0 1. 1 0.55/0. 5 1 0 Reportin

g Unit s Mg « PS/I ftg/l US" 

### us/* us" w't wit mi* pg/e ngit n<

a Paramete r measure d onl y fo r wate r collecte d a t one statio n downstrea m o f th e sewag e treatmen t plant

. b USEP A Metho d fo r Chemica l Analysi s o f Wate r an d Wastes , EP A 600/4-79-020 , Marc h 1979 , revise d Marc h 1993 , o r documente d comparabl e procedure

. c Contrac t Laborator y Reportin g Limits

. Sampl e wa s no t filtered

. e USEP A Contrac t Laborator y Progra m Statemen t o f Wor k fo r Inorganic s Analysis , Multi-media , Multi-concentratio n

SO W 78 8 (Jul y 1988) , Documen t Numbe r ILMO1.0
, Marc h 1990

. Paramete r analyze d t o a lowe r detectio n limi t onl y i n aquati c samplin g event s i n whic h biot a are als o sampled

. AST M = America n Societ y fo r Testin g an d Materials

. CLP- M = Contrac t Laborator y Protocol-M

. CRD L = Contrac t Require d Detectio n Limit

. ID L = Instrumen t Detectio n Limit

. mg/t = milligram s pe r lite r pglt = microgram s pe r lite r /unhos/c m = micromho s pe r lite r

Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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. epa\soils-ri\append-a.ju nTabl e A-15 Bed Material Sample s - Parameter s Analyzed , Analytica l Method s an d Detectio n Limit s Paramete r Sulfat e Chlorid e Cyanid e Metal s (Tota l Only ) Aluminu m Antimon y Arseni c Bariu m Cadmiu m Calciu m Chromiu m Coppe r Iro n Lea d Magnesiu m Manganes e Mercur y Nicke l Potassiu m Seleniu m Silve r Sodiu m Zin c EP

A Metho d 375. 3 325. 3 335. 2 CLP- M
200. 7 CLP- M 204. 2 CLP- M 206. 2 CLP- M 200. 7 CLP- M 200. 7 CLP- M 200. 7 CLP- M 200. 7 CLP- M 200. 7 CLP- M 239. 9 CLP- M 200. 7 CLP- M 200. 7 CLP- M 245. 5 CLP- M 200. 7 CLP- M 200. 7 CLP- M 270. 2 CLP- M 200. 7 CLP- M 200. 7 CLP- M 200. 7 CLP- M 200. 7 CLP- M CRD

L N / A N / A 2
4 0 1 2 2 4 0 1 1,00 0 2 5 2 0 0. 6 1,00 0 3 0. 1 8 1,00 0 1 2 1,00 0 4 Reportin

g Unit s mg/k g ing/k g mg/k g mg/k g mg/k g mg/k g mg/k g mg/k g mg/k g mg/k g mg/k g mg/k g mg/k g mg/k g mg/k g mg/k g mg/k g mg/k g mg/k g mg/k g mg/k g mg/k g NOTES : Metho d 200. 7 CLP- M i s IC P analysis

. Method s 206. 2 CLP-M
, 239. 9 CLP-M
, an d 270. 2 CLP- M are Graphit e Furnac e A A analysis

. Metho d 245. 5 CLP- M i s Col d Vapo r A A analysis

. Metho d 335. 2 CLP- M i s Spectrophotometric

. A l l analysi s followin g CL P methodologie s ma y be fro m eithe r USEP A Contrac t Laborator y Progra m Statemen t o f Wor k for Inorganic s Analysis , Multi-media , Multi-concentratio n

SOW 78 8 (Jul y 1988 ) or Documen t N o

. ILMO1. 0 (Marc h 1990)

. Sampl e specifi c CRDL s fo r soli d sample s ar e adjuste d fo r percen t moisture , an d an y dilutions , an d wil l b e highe r tha n thos e liste d above, mg/k g = milligram s pe r kilogra m Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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. epa\soils-ri\append-a.ju n

### •

Seep s create d b y infiltratio n throug h tailin g impoundments

. • Surfac e wate r runof f fro m naturall y mineralized area s withi n th e watershed

. 

### • Strea m be d sediment s tha t ma y becom e suspende d durin g hig h flows

. • Dissolutio n o f metal s i n strea m be d sediment s a s a resul t o f change s i n p H o r strea m chemistry

. • Spring s o r seep s dischargin g groundwate r tha t ha s bee n i n contac t wit h highl y mineralize d are a o r hydraulicall y connecte d t o a contaminate d aquifer

. 

### • Fluvia l tailing s o r pile s tha t com e i n direc t contac t wit h surfac e wate r flows

. 

### • Discharg e fro m min e drainage s an d portals

. • Runof f adjacen t t o majo r road s wher e sla g or othe r highl y mineralize d material s 

### hav e bee n use d t o "sand " roadways

. • Airborne transpor t o f resuspende d soi l o r min e wast e contaminated wit h metals

. Th e mea n concentration s o f tota l lea d fo r al l station s wer e a s follows : 5,06 8 pg/t durin g th e Ice-Of f event ; 14 6 pg/t durin g th e Sprin g Runof f event ; 199 8 pg/t durin g th e Summe r event ; 4 1 ng/t durin g th e Fal l event ; an d 10 2 g/ t durin g th e Winte r event

. Lea d concentration s i n th e 

### Californi a Gulc h range d fro m a lo w o f 1 5 \*%lt durin g th e Winte r even t t o a hig h o f 38,80 0 \i%ll durin g th e Summe r event

. Tota l lea d concentration s wer e elevate d i n th e tributarie s t o Californi a Gulch
, particularl y i n Orego n Gulc h and Stra y Hors e Gulch
, compare d t o othe r 

### samplin g site s i n th e stud y area . Dissolve d lea d concentratio n ar e generall y no t detecte d i n th e Arkansa s Rive r fo r al l samplin g event s an d ar e no t detecte d i n th e Californi a Gulc h durin g th e Summe r an d Winte r events

. A.3. 9 Meta l Speciatio n an d Sourc e Characterizatio n (Drexler

. 1995 ) 

### Thi s stud y identifie s the lea d specie s i n bot h primar y sourc e material s (tailings , smelte r ash , slag , min e waste ) an d secondar y source s (soil s an d dust ) i n orde r t o provid e informatio n usefu l

Residential-Populate d

Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

. 4800-37-020 5 Interi

m Statu s Repor t

.

Pag

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. epa\soils-ri\append-a.ju n

### fo r the assessmen t o f lea d bioavailabilit y i n soils , min e waste , and dus t fro m Leadville

. The objective s o f th e lea d speciatio n stud y ar e to : 

### Identif y th e principa l source s o f lea d i n th e soil s an d dust s o f th e are a an d t o characteriz e ho w th e lea d specie s diffe r i n thes e materials

. Determin e whethe r a soi l contaminate d wit h tailings , min e waste , smelte r ash , o r sla g exhibit s similar lea d speciatio n distribution s a s th e pur e sourc e materia l (e.g. , tailings)

. 

### Determin e th e ultimat e weatherin g product s an d how the y diffe r i n solubilit y whe n compared t o th e sourc e material

. 

### Explain difference s i n speciatio n pattern s betwee n the suspecte d primar y sourc e material s an d th e impacte d residential soil

. Result s o f thi s investigatio n are foun d i n th e Finding s o f Metal Speciatio n Investigation s a t th e Californi a Gulc h NP L Sit e (WESTON
, 1995 ) A.3.1 0 WESTO N XR F Residentia l Surfac e Soil s Investigatio n fWESTON

. 1991b ) T h e objectiv e o f th e WESTO N Energ y Dispersiv e XR F (EDXRF ) Residentia l Surfac e Soil s 

### Investigatio n wa s t o determin e i f a fiel d portabl e XR F analytica l techniqu e coul d b e use d for th e characterizatio n an d mappin g o f metals-contaminate d

soil s i n th e Populate d Residentia l Soil Stud y Are a o f Leadville

. Thi s investigatio n wa s divide d int o tw o phases

. Th e firs t phas e focuse d o n th e calibratio n o f th e fiel d portabl e XR F instrumen t wit h respec t t o th e soil/min e 

### wast e type s foun d i n th e stud y are a an d wa s designe d t o determin e i f th e fiel d generate d XR F 

### dat a wer e comparabl e i n qualit y t o th e conventiona l fixed-bas e laborator y XR F analytica l technique

. Wit h the successfu l completio n o f the firs t phase , the secon d phas e o f the investigatio n involve d th e collectio n o f soi l sample s usin g a define d samplin g gri d t o characteriz e metal s distributio n i n th e residentia l soil s usin g th e portabl e XR F analytica l technique

.

Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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. epa\soils-ri\append-a.ju nA.3.10. 1

Samplin g Th e samplin g o f residentia l soil s i n Leadvill e durin g th e 199 1 summe r resulte d i n th e collectio n 

### an d analysi s o f approximatel y 3,70 0 samples

. Soi l samplin g occurre d a t 25-foo t intervals , alon g a serie s o f surveye d transects

. The transec t line s fo r samplin g wer e locate d alon g easement s o f street s an d unpave d alleyway s i n residential area s o f Leadville

. Thes e easement s wer e contiguou s t o residentia l propertie s fo r samplin g soils

. Th e samplin g location s an d th e 

### concentration s o f lea d a t eac h locatio n ar e presente d i n Plat e 1

. Durin g Phas e I , 85 0 soi l sample s wer e collecte d a t 25-foo t interval s alon g th e transects

. A t eac h 

### sampl e location , a soi l are a 6 inche s i n diamete r wa s desegregate d wit h a pic k an d shove l t o a dept h o f 6 inches

. Thi s soi l wa s mixe d repeatedl y i n plac e t o mak e i t homogeneou s afte r whic h approximatel y 50 0 gram s (g ) o f soi l wa s plac e i n a plasti c bag , labeled , an d shippe d t o th e 

### laborator y unde r chain-of-custod y procedures

. I n the laboratory , the fiel d mois t sample s i n the plasti c ba g wer e analyze d thre e time s b y the fiel d portabl e XR F instrument

. Thi s mod e o f 

### analysi s wa s analogou s t o i n situ analysis

. Afte r thi s initia l analysi s th e samples wer e drie d overnigh t i n a n ove n a t 100 C
, sieve d t o remov e gras s an d twigs , an d the n thoroughl y mixed

. Th e sample s wer e reanalyzed b y th e portabl e XR F an d th e laborator y KEVE X XR F instruments

. Again , th e sample s wer e analyze d thre e time s b y th e fiel d portabl e XR F instrumen t becaus e o f th e shor t countin g time s involve d an d onl y onc e b y th e KEVE X laborator y instrument

. Durin g Phas e n , 2,85 0 soil s wer e sample d followin g th e sam e procedure s a s i n Phas e I

. Soi l 

### t o a dept h o f 6 inche s wa s mixe d thoroughl y i n plac e t o ensur e th e soi l wa s homogeneous

. Approximatel y 50 0 g o f soi l wa s the n sample d fro m thre e point s tha t wer e locate d 12 0 degree s apar t o n a 4-inc h radius

. Th e soi l wa s place d i n a plasti c bag , labeled , an d sen t t o th e laborator y fo r analysi s b y th e portabl e XR F instrument

. Eac h soi l wa s analyze d thre e times , an d th e analytical value s wer e average d t o provid e th e meta l concentration s i n th e soi l fo r tha t location

. A t ever y 20t h sampl e locatio n a split o f th e soi l sampl e wa s sen t t o th e laborator y fo r 

### analysi s b y th e fixed-bas e XR F instrument

. Originally , th e wor k pla n calle d fo r th e sampl e analysi s t o b e performe d i n th e field

. Wit h thre e samplin g crew s i n th e fiel d collectin g samples , Residential-Populate d

Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

. 4800-37-020 5 Interi

m Statu s Repor t Pag e A-6 6 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

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. epa\soils-ri\append-a.ju n

### i t wa s mor e efficien t t o brin g th e samples t o a centra l fiel d laborator y wher e th e sample s wer e analyzed

. 

### Approximatel y 20 0 split soi l sample s ou t o f a tota l o f 3,70 0 wer e analyze d fo r lea d an d zin c i n th e laborator y usin g CL P protocol

. A.3.10. 2 Result s 

### Forty-fiv e residentia l soil s fro m a 199 0 samplin g effor t conducte d b y Wals h wer e mad e availabl e fo r the Phas e I portio n o f the study

. Durin g the Wals h soi l investigation , thes e soil s wer e 

### analyzed b y th e CL P protoco l an d th e analytica l result s wer e mad e availabl e fo r th e Phas e I 

### portio n o f thi s study

. Te n o f thes e soil s wer e use d t o co-calibrat e th e laboratory-base d KEVE X XK F an d thre e differen t fiel d portabl e X-Me t XR F instruments

. Th e remainin g 3 5 characterize d soil s wer e the n analyzed b y bot h instrument s t o confir m th e accurac y o f th e calibration s o f th e tw o type s o f XR F instruments

. Approximatel y 5 0 percen t o f th e Phas e n soi l samples cam e fro m alleyway s i n close proximit y 

### t o residences

. Thi s stud y prompte d th e questio n o f whether th e concentration s o f lea d i n 

### alleywa y easemen t soil s o r nearb y residential soil s wer e representativ e o f lea d concentration s i n soil s o f backyar d residence s adjoinin g thes e easements

. T o answe r thi s question, 3 8 location s wer e identifie d wher e sample s wer e take n fro m bot h alle y easement s an d nearb y residential soils

. Statistica l compariso n betwee n th e alle y easemen t an d nearb y residentia l soil s showe d n o significan t difference s betwee n th e two

. 

### Th e preliminar y Baselin e Huma n Ris k Assessmen t (WESTON
, 1991c ) establishe d 25 0 micron s a s th e larges t ingestibl e particl e siz e o f concern . Fro m th e 199 1 Phas e I FPXR F study , 6 8 

### sample s wer e randoml y selecte d fro m th e archive d Leadvill e soi l samples

. Ou t o f th e 6 8 samples , 4 0 wer e collecte d fro m th e edg e o f alle y right-of-ways an d th e remainin g 2 8 fro m residentia l yards

. Thes e sample s wer e sieve d an d th e les s tha n 25 0 micro n fractio n wa s sen t t o 

### th e Universit y o f Colorado
, Boulde r fo r analysi s b y EDXRF

. Th e tw o subset s o f dat a wer e analyze d statistically

. Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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m Statu s Repor t Pag e A-6 7 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

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. epa\soils-ri\append-a.ju nFro m

th e 199 1 Phas e H FPXR F study , 8 6 sample s wer e selecte d fro m 1 6 residentia l yard s 

### samplin g location s wher e replicat e sample s ha d bee n taken

. Thes e samples wer e als o sieve d an d th e les s tha n 250 micro n fractio n wa s sen t t o th e Universit y o f Colorado
, Boulde r fo r analysi s b y EDXRF

. Th e analytica l result s fo r bot h Phase s I an d n 25 0 micro n sieve d sample s wer e sen t t o th e Environmenta l Monitorin g System s Laboratory
, La s Vegas , Nevad a fo r compariso n t o th e result s obtaine d b y th e FPXR F on whol e soi l sample s (EPA
, 1993b)

. 

### Th e conclusio n o f thes e tw o analyse s i s tha t a t a 9 5 percen t confidenc e level , th e mea n concentration s o f lea d i n th e whol e soi l sample s an d i n th e 25 0 micro n fraction s ar e significantl y differen t fo r alleyway s (alle y edges ) an d no t significantl y differen t fo r residentia l yar d soils

. Th e mea n concentration s o f lea d i n whol e soi l samples appea r t o b e higher tha n th e mea n lea d concentration s i n th e les s tha n 25 0 micro n fraction s i n th e alleywa y samples

. Therefore , th e 

### mea n concentration s i n whol e soil s ca n b e viewe d a s a conservativ e estimat e fo r th e mea n lea d concentration s i n fin e soi l fractions

. 

### T h e WESTO N XR F Residential Surfac e Soil s Investigatio n confirme d tha t th e fiel d portabl e XR F instrumentatio n i s capabl e o f generatin g dat a comparabl e t o laborator y base d XR F instrumentatio n an d dat a generate d b y us e o f CL P protocol

. Th e highes t lea d concentration s i n soil s wer e foun d i n th e easter n an d southeaster n area s o f Leadville

. Maximu m lea d concentration s range d fro m 10,00 0 t o 28,27 0 mg/kg

. 

### A.3.1 1 Dat a Repor t fo r Lea d Occurrenc e i n an d Immediatel y Adjacen t t o Residentia l Areas

. Californi a Gulc h Site

. Leadville

. Colorad o (Universit y o f Cincinnati

. 1991 ) Base d o n a door-to-doo r censu s conducte d b y th e Universit y o f Cincinnat i an d th e Lak e Count y 

### Healt h Department
, 24 5 residence s wer e selecte d t o participat e i n a n environmenta l samplin g program

. Th e location s o f residence s participatin g i n thi s stud y wer e no t disclosed

. Dust
, paint , water , an d soi l sample s wer e collecte d a t eac h o f thes e residential environment s an d analyzed fo r lead , arsenic , and cadmium

. Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

. 4800-37-020 5 Interi

m Statu s Repor t Pag e A-6 8 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

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. epa\soils-ri\append-a.ju nA.3.11. 1

Dat a Collectio n Proces s Egh t stud y areas , A throug h H , wer e identifie d fro m whic h sample s wer e collecte d i n the 

### Leadvill e area . A nint h are a outsid e o f Leadville
, Are a M , wa s selecte d a s a contro l area . Thes e area s wer e selecte d t o provid e a wid e rang e o f potentia l lea d exposure s fro m dust , soil , paint , an d water

. House s tha t wer e sample d varie d i n thei r proximit y to : know n histori c smelte r operations ; wast e roc k piles ; tailin g piles ; an d sla g piles

. Th e house s sample d als o 

### varie d i n term s o f th e existenc e o f lead-base d paint ; lea d wate r pipes ; an d lead-base d solder

. A.3.11. 2 Sampl e Collectio n 

### Samplin g a t eac h hous e wa s conducte d b y tw o samplin g team s traine d b y th e Universit y o f 

### Cincinnati

. Th e interio r samplin g tea m collecte d interio r dust and wate r samples , and performe d th e interio r an d exterio r lead-in-pain t sampling

. Th e exterio r samplin g tea m collecte d exterio r dus t an d soi l samples

. A.3.11. 3 Interio r Dus t Samplin g 

### Interio r samplin g location s wer e selecte d base d o n hig h traffi c area s suc h a s a n are a adjacen t t o th e fron t door ; a n are a i n th e mos t frequentl y use d roo m (livin g roo m o r kitchen) ; an d a floo r 

### are a nea r th e doorwa y o f th e subjec t child' s bedroom

. A templat e exposin g a 25-c m b y 25-c m are a wa s place d ove r th e are a t o b e sampled

. Th e samplin g apparatu s consiste d o f a monitorin g pump , a n ai r monitorin g cassett e fitte d wit h a 0. 8 p cellulos e acetat e filter , an d a collectio n 

### nozzle

. 

### Ther e i s n o discussio n o f lea d dat a her e sinc e th e samplin g location s remai n confidentia l an d unknow n t o EPA ; however , thi s dat a ca n b e use d fo r ris k assessmen t purposes

.

Residential-Populate d

Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

. 4800-37-020 5 Interi

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. epa\soils-ri\append-a.ju nA.3.1

2 Pre-minin

g Soil s Geochemistr y Repor t (Walsh

. 1993 ) Th e purpos e o f th e Pre-minin g Soil s Geochemistr y Repor t wa s t o determin e pre-minin g soi l 

### meta l concentration s a t th e Californi a Gulch Stud y Are a b y evaluatin g existin g soi l metal s dat a and b y gatherin g additiona l soil s dat a fro m th e mineralize d area s o f Leadville

. Th e metal s evaluate d fo r backgroun d concentration s wer e arseni c (As) , cadmiu m (Cd)
, coppe r (Cu)
, lea d (Pb)
, an d zin c (Zn)

. The objective s o f thi s stud y wer e to :


### • sampl e soi l pedon s withi n th e mineralized zon e tha t ar e relativel y undisturbed ; 

### • produc e a mor e accurat e an d detaile d surficia l geolog y ma p o f th e stud y area ; • develo p an d defin e soil-geologi c unit s i n th e stud y area ; 

### • differentiat e betwee n backgroun d an d disturbe d soi l bodie s i n th e stud y area ; and , • estimat e range s o f pre-minin g concentration s o f metal s i n soils

. 

### Dat a set s utilize d i n thi s stud y ar e primaril y fro m Phas e n Remedia l Investigations a t th e Californi a Gulch NP L Site

. Th e metal s dat a ar e fro m fiv e increment s ( 0 t o 1 , 1 t o 2 , 2 t o 6 , 6 t o 12 , an d 1 2 t o 1 8 inches ) an d fro m surfac e t o approximatel y 6 0 inche s dept h i n soi l backho e pits

. Som e location s wer e sample d b y bot h increment s an d soi l horizons

. Al l soi l sample s wer e analyze d fo r tota l metal s usin g energ y dispersiv e X-ra y fluorescenc e (EDXRF ) o r b y Contract 

### Laborator y Progra m methods

. Durin g thi s study , fou r backho e pit s wer e sample d i n location s eas t o f tow n expecte d t o b e 

### mineralize d and tha t appeare d relativel y undisturbe d b y minin g activities

. Sample s collecte d fro m thes e backho e pit s wer e analyzed t o hel p asses s meta l backgroun d concentration s i n 

### undisturbe d soil s occurrin g ove r mineralized paren t material

.

Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

. 4800-37-020 5 Interi

m Statu s Repor t Pag e A-7 0 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

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. epa\soils-ri\append-a.ju n

### A.3.12. 1

Geologi c Mappin g 

### A detaile d surficia l geologi c ma p wa s produce d t o defin e soil-geologi c units

. Th e origina l surficia l geologi c ma p o f th e stud y are a prepare d b y Woodward-Clyd e Consultant s (WCC ) wa s 

### revise d b y additiona l fiel d mappin g on 1:7,20 0 scal e colo r stere o aeria l photographs

. Th e ma p
wa s the n co-rectifie d wit h th e detaile d soil s ma p o n th e orthophotograph

. Th e new geologi c ma p 

### followe d the establishe d geologi c ag e subdivisions

. A.3.12. 2 Method s fo r Estimatin g Pre-minin g Soi l Meta l Concentration s 

### Pre-minin g soi l meta l concentration s wer e estimate d fo r tw o principl e element s o f th e stud y area : soil-geologi c unit s an d differen t landscap e positions

. 

### Pre-minin g (background ) soi l meta l concentration s wer e estimate d fo r soil-geologi c unit s usin g metal s dat a fro m th e fiv e dept h increment s ( 0 t o 1 , 1 t o 2 , 2 t o 6 , 6 t o 12 , an d 1 2 t o 1 8 inches )


### a t 62 9 locations

. The analyse s incorporate d fiel d documente d soi l condition s includin g disturbanc e fro m minin g activities , depth , geomorphology , an d paren t material

. A limitatio n o f thi s approach , however , i s tha t th e sample s ar e fro m interval s withi n th e to p 1 8 inche s o f th e 

### soi l profile

. I n man y places , min e waste , fil l material , and othe r surfac e disturbance s ar e thicker tha n 1 8 inches

. Becaus e th e estimate d meta l backgroun d range s ma y includ e a mixture o f nativ e soi l an d impacte d material , the y ma y no t accuratel y represen t th e pre-minin g metal s backgroun d


### o f tha t unit

. Usin g anothe r approach , meta l backgroun d range s wer e compute d fo r two generalize d landscap e 

### position s (alluvia l an d upland) , usin g geochemica l dat a fro m 3 3 fiv e foo t dee p soi l backho e pits

. Alluvia l landscape s includ e nin e backho e pit s whil e uplan d landscape s includ e 2 4 backho e pits

. 

### Becaus e soi l backho e pit s ar e dee p an d penetrat e int o th e undisturbe d glacial paren t materials , the y probabl y bette r represen t pre-minin g meta l range s ove r th e entir e site , wherea s th e backgroun d range s compute d for th e soil-geologi c unit s display th e variation s tha t woul d b e expecte d i n differen t paren t material s an d i n material s undergoin g differen t soi l formin g Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

. 4800-37-020 5 Interi

m Statu s Repor t Pag e A-7 1 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

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. epa\soils-ri\append-a.ju nprocesses

.

Th e backgroun d range s compute d fro m th e backho e pit s wer e compare d t o th e range s compute d fo r th e soil-geologi c units

. 

### Backgroun d meta l range s wer e estimate d fo r bot h th e landscap e position s an d th e soil-geologi c 

### unit s b y applyin g the cumulativ e probabilit y graphica l techniqu e t o the correspondin g metal s data

. This method i s commonl y use d i n mineral-exploratio n

t o distinguis h or e grad e meta l abundanc e fro m hos t roc k meta l concentrations

. A step-by-ste p outlin e fo r constructin g 

### cumulativ e probabilit y plot s i s show n i n Tabl e A-16

. Th e cumulativ e probabilit y graphica l procedur e involve s plottin g th e cumulativ e frequenc y o f 

### meta l concentration s o n lo g probabilit y pape r an d partitionin g int o anomalou s an d backgroun d populations

. Th e cumulativ e percen t scal e o n probabilit y pape r i s graduate d s o tha t a norma l 

### distributio n plot s a s a straight line

. A mixtur e o f tw o norma l population s result s i n plot s wit h nearl y linea r segment s separate d b y curve d segment s containin g a n inflectio n point

. Th e 

### inflectio n poin t give s a n estimat e o f th e proportion s o f th e tw o populations

. Onc e th e inflectio n point , whic h partition s the frequenc y distributio n int o backgroun d an d anomalou s populations , 

### i s established , a threshol d valu e i s selected

. A threshol d valu e o f 9 9 percen t fo r backgroun d sample s wa s selecte d for al l backgroun d analyses

. For instance , a threshol d o f 9 9 percen t
mean s tha t 9 9 percen t o f th e backgroun d sample s wer e correctl y identifie d a s backgroun d an d 1 percen t wa s missed

. I n othe r words , th e backgroun d valu e compute d fro m th e cumulativ e 

### probabilit y plot s i s th e uppe r limi t o f backgroun d fo r tha t metal

. Th e lowes t concentration , othe r tha n zero , o f eac h meta l fo r eac h soi l landscap e positio n wa s selecte d t o b e th e lowe r limi t o f 

### background

. Reporte d value s o f zer o wer e no t use d a s th e lowe r limi t o f background , sinc e al l soil s contai n som e amoun t o f As , Cd
, Pb
, Cu
, an d Zn

. Figur e A- 5 i s a n exampl e o f a cumulativ e probabilit y plo t o f P b for soil s o f alluvia l landscap e positions

. Figur e A- 5 graphicall y show s th e inflectio n poin t a t 25 percen t o n th e X axis , o r lo g concentratio n 3. 2 o n th e Y axis

. Th e soli d circle s represen t th e cumulativ e percentage s o f meta l 

### concentration s fro m th e origina l data ; th e "Xs " ar e point s whic h defin e th e backgroun d an d anomalou s populations ; an d th e triangles ar e calculate d chec k points

. Th e close r th e chec k Residential-Populate d

Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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. epa\soils-ri\append-a.ju nTabl e A-1 6 Procedure fo r Constructin g Cumulativ e Probabilit y Plot s
1 ) Meta l dat a wer e converte d t o logarithms

. 2 ) Logarithmi c meta l concentration s wer e classifie d int o 1 0 t o 2 0 groups , wit h a t leas t fiv e samples i n mos t o f the groups

. 3 ) Cumulativ e

percentage s wer e computed , startin g a t th e hig h concentrations , endin g wit h 10 0 percen t a t lo w concentrations

. 4 ) Th e cumulativ e percentage s wer e plotte d against th e lowe r clas s limit s o n probabilit y paper , an d a curv e wa s draw n throug h th e points

. 5 ) Th e inflectio n poin t o f th e curv e wa s selected

. Thi s poin t define s th e approximat e proportion s o f th e tw o populations

. 6 ) P

A = P t /f A wa s compute d fro m eac h cumulativ e dat a point i n populatio n A , wher e P j i s th e observe d cumulativ e percentage , and/] , i s th e proportio n o f sample s fallin g i n Populatio n A

. 7 ) Ne w point s wer e plotte d a t P A . Ste p 6 wa s continue d unti l th e inflectio n poin t wa s reache d o r unti l newl y calculate d point s markedl y diverge d fro m a straight line

. 8 ) A lin e wa s draw n t o fi t the point s plotte d i n Ste p 7

. Thi s line define s the anomalou s population

. 9 ) Analogou s point s wer e compute d startin g a t lo w concentrations , usin g f B (proportio n o f samples i n Populatio n B
, a s determine d b y inflectio n point) , an d cumulativ e percentage s wer e compute d a s 100-P

. A line wa s draw n for backgroun d population

. 10 ) Th e calculate d population s wer e checke d b y combinin g the m i n th e prope r proportions , usin g P

m =f A + fJ* A + fsPs' wher e P

m i s th e cumulativ e percentag e i n th e mixture

. Th e value s o f P

m wer e plotte d an d compare wit h origina l points

. I f P

m point s diverge d significantl y fro m th e origina l dat a points , a slightl y differen t inflectio n poin t wa s selected

. Fro m Sinclai r (1974 , 1976)

.

Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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. epa\soils-ri\append-a.ju nB8X10B 1

4.

2 

## I " S,.
, a Q 

### 6 3 6 

# s 

# I "

3. 0 2. 8 2. 6 2. 4 2. 2 2. 0 1. 8 0

. ""•• * 

### \ \ • Cumulativ e percentag e o f meta l concentration s fro m (h e origina l data

. X Point s tha t defin e th e tw o population s A Chec k point s Backgroun d = 87 0 mg/k g 6 3 Sample s

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^ t 

### s ,

9 0 9 5 9 8 9 9 99. 8 99. 9 99.9 9 CUMULATIV E PROBABILIT Y PLO T FO R FIGUR E P b FO R SOIL S O F ALLUVIA L LANDSCAP E POSITION S A- 5 

### 5 I 

## § 

# p 1
(a g g D M l I

### point

s ar e t o th e origina l dat a point s (cumulativ e percentage s o f meta l concentrations ) th e mor e accurat e th e compute d backgroun d leve l i s fo r tha t meta l (Sinclair
, 1974)

. 

### A threshol d o f 9 9 percen t (o r 1 percen t o n th e botto m lef t o f th e plot ) wa s selecte d an d correspond s t o a lo g concentratio n o f 2.9 4 o r 87 0 mg/k g Pb

. Th e compute d backgroun d leve l
o f 87 0 mg/k g P b represent s th e uppe r limi t o f background

. Th e lowes t P b valu e o f th e alluvia l 

### landscap e positio n wa s 8 0 whic h represent s th e lowe r limi t o f background

. 

### Estimate d backgroun d metal s concentration s fo r eac h soil-geologi c uni t wer e compare d t o mea n meta l value s o f eac h dept h interva l (fo r disturbe d an d undisturbe d soils ) b y soil-geologi c unit

. Backgroun d range s fo r A s an d C d fo r th e soil-geologi c unit s wer e obtaine d b y assignin g th e 

### compute d A s and C d backgroun d value s fro m th e soi l landscap e position s t o th e correspondin g soil-geologi c units

. Thi s wa s don e becaus e 8 0 percen t o f th e dat a fo r thes e tw o metal s wa s 

### below th e establishe d practica l quantitatio n limit

. A.3.12. 3 Developmen t o f Soil-Geologi c Unit s Soil-geologi c unit s wer e develope d s o pre-minin g meta l range s coul d b e evaluated base d o n soi l 

### typ e an d geologi c paren t material

. Th e soil-geologi c unit s ar e hybri d mappin g unit s develope d b y integratin g genera l surficia l geologi c unit s (derive d fro m th e detaile d surficia l geologi c map ) wit h th e correspondin g dominan t soi l type s whic h wer e take n fro m th e soi l ma p o f th e stud y are a 

### (Walsh , 1992a)

. Groupin g th e soil s an d geolog y i n thi s manne r allowe d evaluatio n o f th e dat a base d o n unit s havin g simila r geology , depositiona l age , landscap e positions , soi l type , an d degree o f disturbance

. Tabl e A-1 7 contain s th e relativ e ag e o f th e soil-geologi c units , a descriptio n o f eac h unit , th e acreag e o f eac h soil-geologi c unit , an d th e percen t o f th e tota l area . 

### A.3.12. 4 Distinguishin

g Betwee n Disturbed an d Undisturbe d Soil s T o asses s pre-minin g meta l backgroun d concentration s i n soils , eac h sample d soi l horizo n withi n th e backho e pit s an d soi l sampl e increment s wer e classifie d a s eithe r undisturbe d o r disturbed

. Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

. 4800-37-020 5 Interi

m Statu s Repor t Pag e A-7 J THI S DOCUMEN T WA S PREPARE D B Y RO Y F

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. epa\soils-ri\append-a.ju nTabl e A-1 7 

### Soil-Geologi c Unit s an d Correspondin g Dominan t Soi l Ma p Unit s

P I 8

8 ll^l^^IO^K:v: : : v 

## iiSlilif : 

## I £ iliill^lIP;: ; M/D S (Recent ) A/A S (Recen t - 8,00 0 ybp ) 

### c/u s (Recen t - 140,00 0 ybp ) PD/D S (14,00 0 -30,00 0 ybp ) BL/UL T (140,00 0 ybp ) PBL/UL T ( > 250,00 0 ybp ) B/U T ( > 1,600,00 0 ybp ) TOTA L 

### ;||;:;$j^ ^ 0'p:;i: : : : i::|l:i^in(fe;^

: :;;;::: : ;-!:^;;v\::V : Man-Impacted/Disturbe d Soil s Recen t Alluvia l Deposits / Alluvia l Soil s Colluvia l Deposits/Uplan d Soil s Pinedal e Deposits/Disturbe d Soil s Bul l Lak e Deposits/Uplan d Soils : Leadville
, Troutvill e Pre-Bul l Lak e Deposits/Uplan d Soils : Leadville
, Troutvill e Bedrock/Uplan d Soils : Troutvill e •^;f3^; ^ 

### j^r;?^::; ^

. - ..: . . . •'• : :••'•• • •:••• : y - • -.•: • : xXxX

: • :••••':'• • :•:••'• •' 'X' X

; • :'••: • : : ' : 'x : :':'xx.V: :

. : .Xx'.V. : : : Xx : xXxX.XxXXXx

. .xxX: X

: : : :-:-:-: : x :

. : : : :': : : ; : ; : : : : : ;i: : xXXXr-xXx 1 :

: : x : : •;.• ; •
: Man-Impacte d Deposits : include s tailings , min e spoils , sla g piles , constructio n debris , an d man-mad e fill

. Thi s uni t date s fro m presen t t o histori c minin g activitie s i n th e 1800s

. Geologi c ma p unit s i n thi s groupin g are : m , m/al , m/a3 , m/a4 , m/al , a/f , m/gl , m/g3 , s , an d t

. Recen t Alluvia l Deposits : include s presen t t o Pleistocen e non-glaciate d alluvia l deposits

. Geologi c ma p unit s i n thi s groupin g are : al , ay , af , an d ac . Colluvia l Deposits : include s al l colluvia l deposit s whic h rang e fro m presen t t o Bul l Lake

. Geologic ma p unit s i n thi s groupin g are : cc , cf , cf/a , an d cf/b

. Pinedal e Deposits : includes alluvia l an d glacia l deposit s o f th e Pinedal e glacia l advance

. Geologic ma p unit s i n thi s groupin g are : a4 , a4/a2 , a5 , g4 , an d g5

. Bul l Lak e Deposits : includes alluvia l an d glacial deposit s o f the Bul l Lak e glacia l advance

. Geologic ma p unit s i n thi s groupin g are : a2 , a3 , g2 , an d g3

. Pre-Bul l Lak e Deposits : include s alluvia l an d glacia l deposit s o f th e Pre-Bul l Lak e glacia l advance

. Geologi c ma p unit s i n mi s groupin g are : al , gl , an d glib. Bedrock : include s al l pre-Cenozoi c deposits

. Thes e deposit s rang e fro m Tertiar y throug h Precambrian

. Thi s geologi c ma p uni t correspond s t o th e origina l "b " surficia l geologi c ma p unit

. Dominan

t Soi l :|;||iiiiif ; :iiiiiii^|| : : : { ; ^lfei^Cieoiogies;x:

. 20 , 70 , 72 , 73 , 80 , 81 , 82 , 90 , 92 , 103 , 10 2 40 , 44 , 60 , 61 , 6 3 1 , 55 , 7 0
1 , 13 , 16 , 34 , 44 , 45 , 50 , 55 , 60 , 70 , 75 , 10 0 3 , 4 , 8 , 13 , 50 , 5 5 1 , 3 , 4 , 55 , 5 6
5 5 

### ilfil^xufs l 

# liiiii f

1,13 9

76 8
44 1
93 4
1,89 7
4,32 8
23 1 9,73 8 ;:£i^V:": : :S: : : : : : : : : : : ::>: : : 

### ^mi^m 111:11111 1 11. 5

7.7
4. 5
9. 4
1 9
43. 5
2. 3
97.9 *

1 yb p = year s befor e presen t * Th e tota l doe s no t equa l 100% , becaus e th e surficia l geolog y wa s no t mappe d i n tw o smal l portions (approximatel y 20 0 acres ) o f th e stud y are a du e t o lac k o f aeria l photographi c coverage .Undisturbe d

soi l horizon s sho w n o apparen t evidenc e o f disruptio n o f th e natura l soi l profil e an d lac k visibl e min e waste , fil l material , an d huma n artifacts , wherea s disturbe d soi l horizon s 

### contai n visibl e min e waste , fil l material , and/o r huma n artifacts

. Thes e material s an d soil s wer e identifie d i n th e fiel d an d recorde d o n soi l observation descriptio n form s b y WALS H soi l scientist s durin g th e soi l inventory

. A.3.12. 5 Result s A.3.12.5. 1 Backgroun d Metal Concentration s i n Landscap e Position s 

### T h e backgroun d concentration s compute d fro m cumulativ e probabilit y plot s fo r As , Cd
, Cu
, Pb
, 

### an d Z n for uplan d an d alluvia l soi l landscap e position s are presente d i n Tabl e A-18

. Thes e compute d backgroun d meta l range s wer e the n compared t o commo n meta l range s i n soil s o f th e U.S

. (Tabl e A-19)

. 

### Alluvia l landscap e position s ar e th e unglaciate d bottomlan d drainage s an d moder n floodplain s an d includ e th e Arkansa s Rive r Valle y an d California
, Malta , an d Evan s Gulches

. Uplan d landscap e position s includ e th e elevate d landscape s o f th e stud y area , whic h compris e th e 

### majorit y o f th e stud y are a an d includ e Leadvill e an d al l othe r residentia l areas . Uplan d soil s o f th e stud y are a hav e backgroun d concentration s withi n commo n meta l range s foun d i n soil s o f th e wester n U.S

. Fo r example , th e compute d backgroun d rang e o f P b i n uplan d positions i s 8 t o 15 0 mg/kg , an d th e commo n P b rang e i n wester n U.S

. soil s i s fro m les s 

### tha n 1 0 t o 70 0 mg/kg

. Alluvia l landscap e soil s o n th e othe r han d exhibi t A s an d P b backgroun d 

### concentration s tha t excee d commo n A s an d P b range s foun d i n soil s o f th e wester n U.S

. Fo r example , th e compute d backgroun d rang e o f P b i n alluvia l landscap e position s i s 87 0 mg/kg

. Backgroun d metal s concentration s withi n th e alluvia l landscap e position s ar e naturall y highe r 

### tha n i n uplan d landscapes , becaus e soil s fro m higher position s i n th e watershe d ar e transporte d downgradien t an d deposite d i n o r alon g strea m channe l margin s concentratin g metal s i n th e 

### alluvia l channels , furthermor e alluvia l channel s dissec t mineralized zones .
Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

. 4800-37-020 5 Interi

m Statu s Repor t Pag e A-7 7 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

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. epa\soils-ri\append-a.ju n

### A.3.12.5. 2

Backgroun d Meta l Concentration s i n Soil-Geologi c Unit s 

### T h e range s o f backgroun d concentration s compute d fro m cumulativ e probabilit y plot s fo r Cu
, Pb
, an d Z n fo r soil-geologi c unit s ar e presente d i n Tabl e A-20

. Depth-weighte d meta l average s 

### o f th e incrementa l soi l samples fo r eac h soil-geologi c uni t t o b e use d a s a compariso n t o th e compute d backgroun d meta l range s ar e als o i n Tabl e A-20

. Th e younges t soil-geologi c uni t (M/DS ) exhibit s th e highes t uppe r limi t o f backgroun d Pb
, whic h i s mos t likel y du e t o th e shallo w sampl e depth s an d th e larg e amount s o f min e wast e material s 

### i n thi s unit

. The uppe r limi t o f backgroun d concentration s fo r Cu
, Pb
, and Z n generall y 

### decrease s wit h a n increas e i n ag e o f th e seve n soil-geologi c units

. Mos t o f th e estimate d backgroun d concentration s o f th e soil-geologi c unit s ar e withi n commo n meta l range s i n soil s o f th e western U.S

. (refe r t o Table s A-1 9 an d A-20)

. Th e A s backgroun d rang e o f soil-geologi c uni t A/A S (12 0 mg/kg ) exceed s th e commo n A s range s foun d i n wester n U. S soil s ( < 0. 1 t o 

### 9 7 mg/kg)

. Cadmiu m backgroun d range s o f al l soil-geologi c unit s excee d th e commo n C d range s foun d i n U.S

. soils

. (Ther e i s n o C d rang e presente d i n Schacklett e an d Boernge n (1984 ) fo r wester n U.S

. soils ; however , wester n soil s ten d t o hav e highe r backgroun d metal s level s 

### whe n compare d t o soil s o f th e entir e U.S.)

. A.3.12.5. 3 Meta l Concentration s i n Disturbe d an d Undisturbe d Soil s A s a mean s o f verifyin g th e calculate d backgroun d concentrations , th e calculate d value s wer e compared t o measure d meta l concentration s i n undisturbe d soi l horizon s o f th e backho e pits

. Th e dat a wa s separatel y categorize d b y soi l horizon s A , E
, B
, an d C
, whic h increas e i n dept h 

### fro m shallo w t o paren t roc k material

. Averag e meta l concentration s o f soi l A,E
, B
, an d C 

### horizon s for uplan d and alluvia l soi l landscap e position s ar e i n Tabl e A-21

. For uplan d landscap e soils , th e soi l A horizo n (surfac e horizon ) exhibit s meta l concentration s greate r tha n th e calculate d backgroun d ranges . Th e soi l A horizo n i s generall y 2 t o 3 inche s thic k i n uplan d 

### soil s (Walsh , 1992a)

. Belo w th e A horizon , meta l concentration s fal l t o withi n th e backgroun d ranges . Thes e dat a sugges t that , i n general , downwar d transpor t (exuviation ) o f metal s i s no t
a n activ e proces s i n uplan d landscap e positions

. Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

. 4800-37-020 5 Interi

m Statu s Repor t Pag e A-7 8 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

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, INC.
, EXPRESSL Y FO R EPA

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. epa\soils-ri\append-a.ju nTabl e A-1 8 

### Estimate d Backgroun d Metal Concentration s fo r Uplan d an d Alluvia l Landscap e Position s
Uplan d Landscape s N o

. o f samples No

. o f backho e pit s Alluvia l Landscape s N o

. o f sample s N o

. o f backho e pit s Illitlflillill i

; : : : : . : : : : : : : :o: : : : : : : : : : :.f!lka
; : : : : : ; : : :v: : ::: : :v: : : : 

## liiiiiiiil i 0.3-3 0 14 4 2 4 0.7-12 0 6 4 9 

# lilllillllil : l;ll|jij£gilll:l l 0.01- 4 14 4 2 4 0.5- 8 6 4 9 

# iiiiiiiiii i lllliliil i 0.4-4 0 14 4 2 4 8-19 0 6 4 9 

# IIIII1II1III11 ! psIIJSi^fe^iliiiSJ i 8-15 0 126 1 2 4 80-87 0 63 2 9 

# lillliBII! ! MfMl&W^M 16-10 0 14 4 2 4 37-66 0 6 4 9

1 1 8 sample s wer e omitte d du e t o rejecte d dat a 2 1 sampl e wa s omitte d du e t o rejecte d dat a

Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

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m Statu s Repor t Pag e A-7 9 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

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. epa\soils-ri\append-a.ju n

### Tabl e A-1 9 Commo n Meta l Range s i n Soil s o f th e U.S

.

Schacklett e & Boerngen
, 198 4 Lindsay
, 197 9 

# iiiiliiiiiii iiiiliiii i

< 0. 1 -9 7

1 -5 0 

## 1111 ^ 

# lillllllili l

____ *

0.0 1 - 0. 7 2-30 0

2

- 10 0 < 10-70 0

2-20 0 :'r-: : :-: : :-: : : : : : : : : : :': : :^^. : :': : : : : :-: : : : : ; : : : : :-: : :':-: -

•:-:-:-:-:-:-:-:-:-:-.-.-:-y

— •:•.-:•:•:••.•:•:-:•:::;:•:. : ^:.^^-£4L:<-:

: :^^: 1 0 - 2,10 0

10-30 0

n o reporte d value s

Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

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m Statu s Repor t Pag e A-8 0 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

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. epa\soils-ri\append-a.ju nTabl e A-2 0 

### Estimate d Backgroun d Metal Concentration s an d 

### Dept h Weighte d Average s fo r Soil-Geologi c Unit s

•:-:-••••:':•:'•':•:•.•:•:• •

x- : x : x : x : : : x : : x : -:•:•:'•'.-•' •' -.•:' •

:•'• : x : x-:':': : : x : : : x : : ; : : x'x : : : : x 'X; x -; X x ••:•:•

. : : x - .-'•'.'• : '.•:•'• x- x : : x : :•.;

. -:•.• : -:•:•'•:•:•••:•:- • -: : •; • - : : : x : : x : : ; x : : M/D S Backgroun d Rang e Weighte d Average

2 N o

. o f samples

3 A/A S Backgroun d Rang e Weighte d Averag e N o

. o f sample s 

### c/us Backgroun d Rang e Weighte d Average N o

. o f samples PD/D S Backgroun d Rang e Weighte d Averag e N o

. o f sample s BL/UL T Backgroun d Rang e Weighte d Averag e N o

. o f sample s PBL/UL T Backgroun d Rang e Weighte d Averag e N o

. o f sample s B/U T Backgroun d Range Weighte d Averag e N o

. o f sample s 

# liiiHllll I 

# tiillllllli i
0.3-3 0 8 6 14 4 0.7-12 0 2 7 6 4 0.3-3 0 1 2 14 4 0.3-3 0 3 6 14 4 0.3-3 0 2 3 14 4 0.3-3 0 4 6 14 4 0.3-3 0 3 14 4 0.01- 4 1 6 14 4 0.5- 8 9 6 4 0.01- 4 8 14 4 0.01- 4 9 14 4 0.01- 4 4 14 4 0.01-4 4 14 4 0.01- 4 2 14 4 2-21 0 13 9 45 9 6-15 0 12 0 24 3 2.5-17 0 3 9 11 0 1.6-20 0 14 0 39 3 0.7-8 0 4 8 98 0 1.5-15 0 4 5 1,11 7 0.5-6 5 1 1 3 5 23-63 0 2,41 7 46 5 21-26 0 1,55 4 27 5 18-46 0 1,19 3 11 4 33-27 0 1,33 2 41 3 6-16 0 61 1 98 4 2-35 0 47 7 1,31 3 19-21 0 16 5 3 5 45-22 0 1,75 2 46 5 35-63 0 1,14 6 27 5 22-22 0 1,34 3 11 4 59-27 0 1,56 4 41 3 17-21 0 75 2 98 4 15-26 0 57 8 1,31 3 46-30 0 27 8 3 5 Backgroun d range s obtaine d fro m soi l landscap e position s Weighte d average s calculate d usin g incrementa l sample s withi n eac h soil-geologi c uni t Numbe r o f samples use d t o calculat e th e backgroun d rang e

Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

. 4800-37-020 5 Interi

m Statu s Repor t Pag e A-8 1 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

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. epa\soils-ri\append-a.ju n

### Tabl e A-2 1 Compariso n o f Soi l Horizo n Averag e Metal Concentration s t o Backgroun d Concentrations

1 

### Illlil i t&:<+-i-j&-tt5:j5;s.y

: - mm&&mm 

# lllill i liiipi i :-:•:•:-:•:•:-:-:•:-*:-•!*:-:•:-:.:•:-:::.;• : 

# llilll l IfSJil l UPLAN D A E B C backgroun d 

### 1 1 1 3 2 3 1 9 14 4 4 1 

### 8 7 

### 10 3 0 7. 6 2 0.7 0.6 4 4 6 9 11 11 4 0 MS 

### 110 78 

### 68 15 0 43 5 72 

### 91 77 10 0 ALLUVIA L SOIL S A B C backgroun d 6 2 8 6 4 27 

### 10 18 12 0 2 0 

### 4 9 8 27 0 179 19 8 19 0 436 182 

### 223 87 0 2,20 4 63 9 80 1 66 0

1 Al l dat a ar e fro m undisturbe d soil s only

. Number s i n bol d italiciz e typefac e ar e a t o r belo w th e estimate d backgroun d concentratio n for tha t elemen t an d landscap e position

.

Residential-Populate d Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

. 4800-37-020 5 Interi

m Statu s Repor t Pag e A-8 2 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

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. epa\soils-ri\append-a.ju n

### Cadmium
,

Cu
, an d Z n concentration s i n C horizon s o f alluvia l soil s excee d th e calculate d 

### backgroun d range s fo r alluvia l soils

. Th e averag e Z n concentration i n th e A horizo n o f alluvia l landscap e position s (2,20 4 mg/kg ) excee d th e commo n range s o f Z n foun d i n soil s o f th e wester n U.S

. Additionally , mos t o f th e averag e C d an d C u concentration s i n soi l horizon s o f alluvia l landscape s excee d commo n range s i n soil s o f th e U.S

. This dat a implie s tha t exuviatio n o f Cd
, Cu
, an d Z n i s a n activ e proces s i n th e alluvia l landscap e soils

. 

### Metal s dat a fro m undisturbe d soi l C horizon s bes t reflec t the chemica l compositio n o f the paren t 

### material , or pre-minin g metal s condition s i n soils

. Wals h (1992a ) demonstrate d tha t elevate d meta l level s i n surfac e horizon s fro m min e waste , slag , smelte r emissions , and fil l materia l 

### seldo m influenc e meta l level s i n nativ e C horizon s tha t ar e wel l belo w th e surface

. Th e averag e 

### meta l concentration s fro m undisturbe d uplan d soi l C horizon s al l fal l withi n the backgroun d range s calculate d fro m th e cumulativ e probabilit y plot s (Tabl e A-21)

. Mea n metal s concentration s i n undisturbe d soil s decrease t o th e calculate d pre-minin g value s for eac h soil-geologi c uni t a t 2 t o 6 inche s dept h fo r th e fiv e metals , wit h th e exceptio n o f P b an d Z n i n the alluvia l (A/As ) an d the Pinedal e (PD/DS ) soil-geologi c units

. Thes e exception s ar e th e resul t o f th e physica l and chemica l propertie s o f th e soil s withi n thes e soil-geologi c units ; bot h o f whic h ar e locate d i n area s tha t wer e impacte d b y place r mining , aci d min e drainage , 

### smelting , and urba n development

. A/A S commonl y contain s fluvia l tailings , suc h a s the Arkansa s Rive r floodplain , an d Malt a an d Californi a Gulches

. PD/D S i s generall y compose d


### o f variou s type s o f fil l materia l an d min e waste , an d include s muc h o f Leadvill e proper , Stringtown
, an d Lak e For k Traile r Park

. A. 4 REFERENCE

S 

### ASARCO
, Inc

. 1991

. Lette r t o Mr

. Kennet h Wangeru d date d 2 8 Octobe r 1991

. ASARCO
, Inc

. The Denve r & Ri o Grand e Wester n Railroa d Company
, and Resurrectio n Minin g Company

. 1993

. Screenin g Feasibilit y Stud y fo r Remediatio n Alternatives , Draf t Final , Californi a Gulc h Site
, Leadville
, Colorado

. Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

. 4800-37-020 5 Interi

m Statu s Repor t Pag e A-8 3 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

. WESTON
, INC.
, EXPRESSL Y FO R EPA

. I T SHAL L NO T B E RELEASE D O R DISCLOSE D I N WHOL E O R I N PAR T WITHOU T TH E EXPRESS
, WRITTE N PERMISSIO N O F EPA

. epa\soils-ri\append-a.ju n

### CD M (Cam p Dresse r & McKee , Inc. ) 1991a

. Prepare d fo r Resurrectio n Minin g Company

. 

### Soil s Investigatio n Wor k Plan
, Californi a Gulc h CERCL A Site
, Leadville
, Colorado

. CD M (Cam p Dresse r & McKee , Inc.)

. 1991b

. Prepared fo r Resurrectio n Minin g Company

. Samplin g an d Analysi s Plan
, Final. , Californi a Gulc h CERCL A Site
, Leadville
, Colorado

. CD M (Cam p Dresse r & McKee , Inc.)

. 1992

. Prepared fo r Resurrectio n Minin g Company

. 

### Metal Speciatio n an d Sourc e Characterizatio n Wor k Plan
, Californi a Gulc h CERCL A Site
, Leadville
, Colorado

. CD M (Cam p Dresse r & McKee , Inc.)

. 1994

. Soil s Investigatio n Dat a Report
, Californi a Gulch Site
, Leadville
, Colorado

. C H 2 M Hill , Inc

. 1987

. Phas e I Remedia l Investigatio n Report
, Californi a Gulc h Site
, 

### Leadville
, Colorado

. Chryssoulis
, S.L

. 1992

. Prepare d fo r Resurrectio n Mining , Inc

. Meta l Speciatio n an d Sourc e 

### Characterization
, Californi a Gulc h CERCL A Site
, Leadville
, Colorado

. Colorad o Climat e Center
, Colorad o Stat e University , Ft

. Collins
, Colorado

. 

### Colorad o Departmen t o f Health , Universit y o f Colorado
, an d U.S

. Departmen t o f Healt h an d Huma n Services

. 1989

. Leadvill e Heav y Metal s Exposur e Study
, Leadville
, Colorado

. Drexler
, J.W

. 1994

. Speciation
, Exten t an d Sourc e o f Contaminatio n at Californi a Gulc h 

### CERCL A Site
, Leadville
, Colorado

. 

### Drexler
, J.W

. 1994

. Persona l Communicatio n fro m Joh n Drexler
, Universit y o f Colorado
, Boulde r t o Fran k J

. Kabot , Ro y F

. Weston , Inc. , Denver
, Colorado
, Januar y 1994

. 

### EP A (U.S

. Environmenta l Protectio n Agency)

. 1988

. Guidanc e fo r Conductin g Remedia l 

### Investigation s an d Feasibilit y Studie s Unde r CERCLA
, Interi m Final

. EPA/540/G

89/004 , OSWE R Directiv e 9355.3-01

. Offic e o f Emergenc y an d Remedia l Response

. E P A (U.S

. Environmenta l Protectio n Agency)

. 1993a

. Fina l Screenin g Feasibilit y Stud y Fo r 

### Remediatio n Alternatives , Californi a Gulc h NP L Site
, Leadville
, Colorado

. EP A (U.S

. Environmenta l Protectio n Agency)

. 1993b

. Statistica l Compariso n o f Lea d Concentration s i n Whol e an d Fin e Soi l Fraction s fro m Californi a Gulch (Leadville ) 

### Superfun d Site
, Leadville
, Colorado

. Environmenta l Monitorin g System s Laboratory
, La s Vegas , Nevada

. E- S (Engineering-Science
,

Inc. ) 1986

. Prepare d fo r Colorad o Department o f Law

. 

### Leadville/Stringtow n Soil s Investigation , Leadville
, Colorado

. Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

. 4800-37-020 5 Interi

m Statu s Repor t Pag e A-8 4 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

. WESTON
, INC.
, EXPRESSL Y FO R EPA

. I T SHAL L NO T B E RELEASE D O R DISCLOSE D I N WHOL E O R I N PAR T WITHOU T TH E EXPRESS
, WRITTE N PERMISSIO N O F EPA

. epa\soils-ri\append-a.ju n

### Geraght

y & Miller , Inc

. 1988

. Prepare d fo r Colorad o Department O f Highways

. Metal s Concentration s an d Specia l Handlin g Consideratio n fo r Soil s Adjacen t t o Stat e Highwa y 24 , Leadville
, Colorado

. 

### Jacob s Engineerin g Group
, Inc

. 1991

. Historica l Minera l Processin g Operation s o f th e Leadvill e Minin g District
, Californi a Gulc h Superfun d Site
, Leadville
, Colorado

. Kabata-Pendias
, A

. an d H

. Pendias

. 1984

. Trac e Element s i n Soil s an d Plants
, CR C Press
, Boc a Ratan

. Kurtz , J

. an d R

. Bryan

. 1993

. Nature , Exten t an d Sourc e o f Contaminatio n a t th e Californi a Gulc h NP L Site

. 

### Lindsay
, W.L

. 1979

. Chemica l Equilibri a i n Soils
, Joh n Wile y & Sons
, Ne w York

. M- K (Morriso n Knudsen , Inc.)

. 1992

. Lea d Sla g Pil e Remedia l Investigation , Californi a Gulc h 

### Site
, Leadville
, Colorado

. Universit y o f Cincinnati
, Departmen t o f Health

. 1991

. Prepared fo r ASARCO/Resurrection

. Dus t Wor k Plan
, Leadville
, Colorado

. Wals h (Wals h & Associates , Inc.)

. 1988

. Soi l Investigation s i n th e Leadvill e Stud y Area , Lak e 

### County
, Colorado

. Prepared fo r Joh n Jacus , J.D.
, Bradly
, Campbell
, an d Carney

. March , 1988

. Wals h (Wals h & Associates , Inc.)

. 1990

. Residentia l Surfac e Soil s an d Househol d Dus t Sampling
, Californi a Gulch Site
, Leadville
, Colorado

. Wals h (Wals h & Associates , Inc.)

. 1992a

. Soil s Investigatio n an d Mapping , Californi a Gulc h Site
, Leadville
, Colorado

. 

### Wals h (Wals h & Associates , Inc.)

. 1993

. Prepare d fo r ASARCO
, Inc

. Smelte r Remedia l Investigatio n Report
, Volume s I , U , an d HI , Californi a Gulc h Site
, Leadville
, Colorado

. W C C (Woodward-Clyd e Consultants
, Inc.)

. 1991a

. Prepare d fo r ASARCO
, Inc

. Remedia l Investigatio n Scopin g Document
, Californi a Gulc h Site
, Leadville
, Colorado

. W C C (Woodward-Clyd e Consultants
, Inc.)

. 1991b

. Prepare d fo r ASARCO
, Inc

. Smelte r Sit e Investigatio n Wor k Plan
, Californi a Gulc h Site
, Leadville
, Colorado

. W C C (Woodward-Clyd

e Consultants
, Inc.)

. 1991c

. Prepare d fo r ASARCO
, Inc

. Soi l 

### Investigatio n Wor k Plan
, Draf t Final , Californi a Gulc h Stud y Area , Leadville
, Colorado

.

Residential-Populate d Soil s Stud y Area Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Control No

. 4800-37-020 5 Interi

m Statu s Repor t Pag e A-85 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

. WESTON
, INC.
, EXPRESSL Y FO R EPA

. I T SHAL L NO T B E RELEASE D O R DISCLOSE D I N WHOL E O R I N PAR T WITHOU T TH E EXPRESS
, WRITTE N PERMISSIO N O F EPA

. epa\soils-ri\append-a.ju n

### WC C (Woodward-Clyd e Consultants
, Inc.)

. 1991d

. Th e Surfac e Water , Be d Materia l an d 

### Aquati c Ecosyste m Dat a Collectio n Progra m Wor k Plan
, Californi a Gulch
, Leadville
, Colorado

. W C C (Woodward-Clyd e Consultants
, Inc.)

. 1992a

. Prepared fo r Res-ASARCO
, Inc

. Air Qualit y Monitorin g Report

. Volume s I and n . Californi a Gulch Site
, Leadville
, 

### Colorado

. W C C (Woodward-Clyd e Consultants
, Inc.)

. 1992b

. Prepared fo r ASARCO
, Inc

. Smelte r Sit e Reconnaissance
, Californi a Gulc h Site
, Leadville
, Colorado

. WC C (Woodward-Clyd

e Consultants
, Inc.)

. 1993c

. Surfac e Wate r Remedia l Investigatio n Report
, Californi a Gulc h Site
, Leadville
, Colorado

. 

### W C C (Woodward-Clyd e Consultants
, Inc.)

. 1993d

. Prepared fo r ASARCO
, Inc

. Dat a Repor t fo r Lea d Occurrenc e I n an d Immediatel y Adjacen t t o Residentia l Area, Californi a Gulc h Site
, Leadville
, Colorado

. WESTO N (Ro y F

. Weston , Inc.)

. 1990

. Prepare d fo r th e U.S

. Environmenta l Protectio n 

### Agency , Regio n Vm

. Residentia l Soil s Samplin g an d Ai r Monitorin g Wor k Plan
, Californi a Gulch
, Leadville
, Colorado

. WESTO N (Ro y F

. Weston , Inc.)

. 1991a

. Prepare d fo r th e U.S

. Environmenta l Protectio n Agency , Regio n Vm , Sit e Managemen t Plan
, Volum e m , Californi a Gulc h NP L Site
, 

### Leadville
, Colorado

. WESTO N (Ro y F

. Weston , Inc.)

. 1991b

. Prepared fo r th e U.S

. Environmenta l Protectio n 

### Agency , Regio n VEI L Soi l Samplin g an d X-ra y Fluorescenc e Analysi s Wor k Plan
, Leadville
, Colorado

. WESTO N (Ro y F

. Weston , Inc.)

. 1991c

. Preliminar y Huma n Health , Baselin e Ris k 

### Assessment , Californi a Gulc h Site
, Leadville
, Colorado

. WESTO N (Ro y F

. Weston , Inc.)

. 1993

. Prepared fo r th e U.S

. Environmenta l Protectio n Agency , Regio n Vm

. Residentia l Area s Enforcemen t Suppor t Wor k Plan
, Revisio n 3 , 

### Californi a Gulch Site
, Leadville
, Colorado

. WESTO N (Ro y F

. Weston , Inc.)

. 1995

. Prepare d fo r th e U.S

. Environmenta l Protectio n Agency , Regio n VIE

. Draf t Fina l Finding s o f Meta l Speciatio n Investigation s a t th e Californi a Gulc h NP L Site

.

Residential-Populate d

Soil s Stud y Are a Consolidate d Finding s Repor t APPENDI X A Jun e 199 6 Documen t Contro l No

. 4800-37-020 5 Interi

m Statu s Repor t Pag e A-8 6 THI S DOCUMEN T WA S PREPARE D B Y RO Y F

. WESTON
, INC.
, EXPRESSL Y FO R EPA

. I T SHAL L NO T B E RELEASE D O R DISCLOSE D I N WHOL E O R I N PAR T WITHOU T TH E EXPRESS
, WRITTE N PERMISSIO N O F EPA

. epa\soils-ri\append-a.ju nAPPENDI X B EPA/EMS L FIEL D PORTABL E XR F REPORT S

### EPA/600/R-93/073 

### Marc h 199 3 

## A N X-RA Y FLUORESCENC

E SURVE Y O F LEA D CONTAMINATE D RESIDENTIA L SOIL S I N LEADVILLE
, COLORADO : A CAS E STUDY b y 

### C A

. Kuhari c an d W.H

. Cot e 

### Lockhee d Environmenta l Systems an d Technologie s Compan y La s Vegas , Nevad a


### an d A.K

. Singh an d D

. Gonzale s Universit y o f Nevada , La s Vega s 

### Harr y Rei d Cente r for Environmenta l Researc h La s Vegas , Nevad a 

### Projec t Office r Kennet h W

. Brow n 

### Technolog y Suppor t Cente r fo r Monitorin g an d Sit e Characterizatio n Environmenta l Monitorin g System s Laborator y 

### La s Vegas , Nevad a ENVIRONMENTA L MONITORIN G SYSTEM S LABORATOR Y OFFIC E O F RESEARC H AN D DEVELOPMEN T U.S

. ENVIRONMENTA

L PROTECTIO N AGENC Y L A S VEGAS
, NEVAD A 89193-347 8 Printed on Recycled Paper

### TABL E O F CONTENT S NOTIC E

........................................................ . i i 

### TABL E O F CONTENT

S

............................................ . il l LIS T O F FIGURE S

................................................ . v 

### LIS T O F TABLE S

................................................. . v i ACKNOWLEDGEMENT

S

.......................................... . vi i 

### FOREWOR D

.................................................... . 1 

### INTRODUCTIO

N

................................................. . 2 Backgroun d

................................................. . 2 Histor y .................................................... . 2 

### Sit e Descriptio n ............................................... . 3 Migratio n o f Wast e Material s .................................... . 3 

### The Rol e o f EMSL-La s Vegas ................................... . 4 PRINCIPLE

S O F X-RA Y FLUORESCENC

E

........................... .

4 TH E X-ME T 88 0

............................................ . 5 TH E KEVE X 77 0

........................................... . 5 INSTRUMEN

T CO-CALIBRATIO N

.................................. . 5 

### SAMPL E HANDLIN

G

............................................ . 8 FIEL D SAMPLIN

G

.......................................... . 8 SAMPL E PREPARATIO

N

.................................... . 8 Th e Firs t 85 0 samples .................................... . 8 Th e Res t o f th e Sample s .................................. . 9 DATABAS

E MANAGEMEN

T

....................................... . 9 QUALIT Y CONTRO L

............................................. . 9 INTERNA

L CONSISTENC

Y

................................... 1 0 QUALIT Y CONTRO L CHART S

............................... .

1 0 CL P VERSU S X-MET s ...................................... . 1 1 

### PRECISION
, ACCURAC Y AN D DETECTIO N LIMIT S

............. .

1 3 TOTA L VERSU S ESTIMATIO

N ERRO R

........................ .

1 6 FALS E POSITIVES/FALS

E NEGATIVE

S

............................. .

1 6
i l l

### LIS T O F FIGURE S 

### Figur e 1

. Calibratio n result s fo r th e Keve x an d X-Met s 1 , 2 , an d 3

. ............ .

7 

### Figur e 2

. Correlatio n plot s betwee n Keve x an d moist/dr y X-Met

. ............. .

1 0 Figur e 3

. Qualit y control chart s fo r Keve x an d X-Me t #1

. .................. .

1 2 

### Figur e 4

. Correlatio n plo t betwee n CL P an d combine d X-Mets , an d Kevex

. ..... . 1 3 Figur e 5

. Frequenc y distributio n o f %RS D fo r mois t fiel d duplicates

. .......... . 1 5 Figur e 6

. Fals e negative s an d fals e positive s ............................. .

1 8

### ACKNOWLEDGEMENT S 

### Th e author s ar e indebte d t o Mr

. Ke n Wangerud , th e Remedia l Projec t Manager , personne l fro m th e Ro y F

. Weston , Inc. , Denve r office , an d t o Dr

. Re x Brya n an d Dr

. Joh n Drexle r fo r thei r valuabl e technica l suggestion s an d advice

.

vi i

### FOREWOR D



### Continuin g concer n ove r th e advers e impact s t o huma n healt h due t o exposur e t o lea d has prompte d characterizatio n effort s a t numerou s site s acros s th e Unite d States

. On e 

### o f th e primar y potentia l exposur e route s i s throug h ingestio n an d inhalatio n o f lea d contaminate d soils

. Thi s proble m ca n b e seriou s a t ol d minin g an d smeltin g sites , especiall y 

### i n th e wester n Unite d States

. T h e Californi a Gulc h Superfun d Sit e i n Leadville
, Colorad o wa s adde d t o th e Nationa l Priorit y Lis t (NPL ) i n 1983

. I t i s a n histori c minin g an d smeltin g sit e tha t i s 

### currentl y th e focu s o f extensiv e studie s o n soi l lea d contaminatio n an d bioavailability

. 

### Studie s o f groun d an d surfac e wate r impact s ar e als o i n progress

. Personne l fro m th e Environmenta l Protectio n Agencie s (EPA ) Environmenta l Monitorin g System s Laborator y a t La s Vega s (EMSL-LV)
, th e Denve r offic e o f Ro y F

. Weston , Inc. , an d Geosta t Systems
, Inc

. (GSI ) use d field-portabl e X-ra y fluorescenc e (FPXRF ) t o determin e th e spatia l 

### distributio n o f lea d concentration s i n residentia l soils

. Thi s repor t detail s th e FPXR F progra m sampl e collection , preparation , an d analysi s 

### procedures , databas e management , an d progra m qualit y assuranc e effort s a t Leadville

. Th e progra m clearl y demonstrates tha t small , fiel d portabl e XR F instrumentatio n ca n produc e 

### larg e quantitie s o f acceptabl e qualit y dat a i n a timel y an d cost-efficien t manne r whe n used properly

. 

### Whe n combine d wit h th e result s o f bloo d lea d level an d bioavailabilit y studies , thi s dat a ca n hel p t o develo p a tru e assessmen t o f th e risk s pose d b y lea d i n th e residentia l soil s o f Leadville

.

### Eventually
,

th e minin g an d processin g turne d fro m th e oxidized , carbonat e ore s t o th e les s desirabl e sulfid e ore s o f th e mor e mundan e metals , lead an d zinc

. Activit y sinc e ha s 

### bee n cyclic , followin g trend s i n th e bas e metal s markets

. Tota l meta l productio n t o 196 6 wa s abou t 24,000,00 0 tons

. Ther e i s currentl y onl y on e activ e majo r operatio n i n th e area , ASARCO' s Blac k Clou d Mine

. Th e las t smelte r cease d operation s i n 1960

. T h e extensiv e undergroun d minin g activit y lef t a legac y o f drainag e tunnels , perhap s mos t notabl y th e Ya k tunnel , an d numerou s min e wast e roc k an d tailing s pile s dottin g th e landscape , almos t entirel y t o th e eas t an d upslop e o f th e town

. Th e processin g activities , 

### whic h wer e scattere d aroun d th e town , lef t behin d larg e amount s o f slag

. Owin g t o th e relativ e inefficienc y o f th e recover y method s o f th e time , muc h o f th e wast e materia l 

### contain s hig h amount s o f lea d an d zinc , alon g wit h som e othe r metals

. 

### A preliminar y EP A sit e evaluatio n too k plac e i n 198 2 an d 1983 , an d th e sit e wa s place d o n the NP L i n 1983

. The initia l concer n wa s o n the effluen t fro m the Ya k tunnel

. A surg e pon d an d treatmen t syste m hav e sinc e bee n constructe d t o dea l wit h thi s aspec t o f 

### th e minin g legacy

. However , a s i s sometime s th e cas e aroun d ol d minin g districts , materia l ha s bee n take n fro m abandone d dump s fo r us e a s fill , sla g ha s bee n use d a s railroa d ballast , 

### an d i t ha s bee n crushe d fo r us e o n street s i n th e winter

. This use , take n i n conjunctio n wit h the sprea d o f smelte r dus t and win d transpor t o f fin e graine d particle s fro m variou s dumps , prompte d concer n abou t th e effect s o f lead o n peopl e livin g i n th e town , especiall y th e children

. Sit e Descriptio n 

### Th e tow n o f Leadvill e lies abou t 10 0 mile s southwes t o f Denver

. I t i s situate d o n th e wester n slop e o f th e Mosquit o Range
, jus t eas t an d upslop e o f th e Arkansas River
, a t a n 

### elevatio n o f approximatel y 10,20 0 feet

. Th e minin g activit y wa s predominantl y o n th e easter n sid e o f town , alon g th e drainage s o f California
, Evans
, Stray Horse , Oregon , Malt a an d Georgia Gulches

. Th e are a lies withi n th e Colorad o Minera l Bel t an d i s highl y 

### mineralized 0



### . 

### The soil s i n the affecte d are a ar e sand y loam s t o gravell y sand y loams , wit h varyin g amount s o f admixe d slag s an d tailings

. The Leadvill e sand y loa m predominates , wit h lesse r 

### amount s o f Pierian an d Troutvill e gravell y sand y loam s present 0 

### *

. Larg e pile s o f sla g an d tailing s ar e als o scattere d aroun d th e site

. Migratio n o f Wast e Material s Contaminan t transpor t occurre d fro m natura l processes , suc h a s win d an d wate r dispersion , bu t i n Leadvill e a s previousl y stated , th e proble m wa s exacerbate d b y huma n impacts , rangin g fro m smelte r stac k emission s t o slag s that wer e crushe d an d sprea d on ic y 

### road s an d use d fo r railroa d ballast

. Tailing s an d min e wast e roc k wer e thoroughl y mixe d int o loca l soil s b y ove r a centur y o f minin g an d commercia l activitie s wher e thes e material s

### th e photo n bombardment fluoresc e simultaneousl y t o produc e a spectru m o f characteristi c 

### radiation

. I t i s thi s spectru m tha t th e XR F detecto r sense s an d counts

. Ther e ar e tw o type s o f XR F spectrometers , energ y dispersiv e and wavelengt h dispersive

. The principa l difference s ar e i n the metho d o f detectio n o f the fluorescen t energie s o f th e specime n an d th e metho d o f quantifyin g th e analyte s o f interest

. Fo r mor e detaile d informatio n o n X-ra y fluorescence , th e reade r i s referre d t o Jenkin s e t al. (4)



### . TH E X-ME T 88 0 Th e X-Me t 88 0 use d on th e Leadvill e sit e i s a field-portable , energ y dispersiv e XR F spectromete r markete d b y Outokump u Electronics
, Inc. , Langhorne
, PA

. Th e uni t i s self

contained , batter y powered , microprocesso r based , an d weigh s 8. 5 kg

. The surfac e analysi s prob e i s specificall y designe d fo r fiel d use . Th e X-Me t 88 0 i s hermeticall y seale d and can 

### b e decontaminate d wit h soa p an d water

. The prob e include s two radioisotop e sources , Americium-24 1 an d Curium-244
, a proportiona l tub e counter , an d th e associate d electronics

. Th e sourc e i s protecte d b y a Nuclea r Regulator y Commissio n approve d safet y shutter

. Th e electroni c uni t ha s thirty-tw o calibratio n memorie s calle d "model"

. Eac h mode l ca n b e independentl y calibrate d for a s man y a s si x elements

. Usin g a multivariat e regressio n procedur e wit h th e prope r isotop e sources , th e instrumen t ca n b e calibrate d t o measur e 

### element s fro m silico n t o uranium

. Unknow n sampl e intensitie s ar e the n compare d t o th e calibratio n curve s t o yiel d quantitativ e concentrations

. THEKEVEX77 0 

### Th e Keve x 77 0 i s a laboratory-grade , energ y dispersiv e XR F instrumen t markete d b y Fison s Instruments , Sa n Carlos
, CA

. The instrumen t contain s a 19 8 watt , R h anode, liquid

coole d X-ra y tube, an d a cryogenicall y cooled , lithiu m drifte d silico n soli d stat e detector

. Optima l excitatio n condition s for analyte s rangin g fro m N a t o U ca n b e achieve d usin g tub e 

### direc t excitatio n wit h filter s o r usin g secondar y target s fo r essentiall y monochromati c excitation

. Th e highe r resolutio n o f th e Keve x (ove r fiv e time s tha t o f th e X-Met ) allow s fo r excellen t qualitativ e scan s fo r analyte s that interfer e wit h th e analyte s o f interest

. 

### Calibratio n curve s wer e chose n ove r Fundamenta l Parameter s (FP) 1 

### fo r quantitatin g th e analyte s o f interest

. I t wa s decide d i n committe e tha t calibratio n curve s base d o n a suit e o f sit e specifi c calibratio n standard s woul d b e a mor e robus t approach tha n usin g FP

. INSTRUMEN T CO-CALIBRATIO

N Forty-fiv e residentia l soi l sample s fro m a 199 0 samplin g effor t b y Wals h an d 

### Associates , Denver
, Colorado
, wer e availabl e wit h correspondin g EP A CL P analytica l results

. 'Fundamenta l Parameter s i s a mathematica l approac h whic h resolve s analyt e interference s an d produce s quantitativ e result s fo r al l analyte s i n th e sample

.LEA

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### Figur e 1

. Calibratio n result s fo r th e Keve x an d X-Met s 1 , 2 , an d 3

.

### diamete r

polyethylen e X-ra y cel l an d seale d wit h 0. 2 mi l polypropylen e film

. Th e cuppe d sampl e wa s the n analyze d o n th e Keve x an d agai n o n on e o f th e thre e X-Mets

. Th e 

### remainin g drie d soi l wa s pu t int o archive , stil l unde r chain-of-custody

. Al l Pyre x loa f dishe s wer e decontaminate d wit h a n Alconox/distille d wate r solution , rinse d wit h distille d water , an d ai r dried

. 

### Al l X-Me t measurement s wer e don e i n triplicat e and th e value s average d partl y du e t o the relativel y shor t acquisitio n tim e (3 0 second s livetime) , but mostl y t o obtai n a mor e representativ e composit e value o f eac h sample

. A sampl e i s measured onl y onc e on th e Keve x du e t o th e lon g acquisitio n tim e (200 second s livetime 2 

### )

. T h e Res t o f th e Sample s 

### Onc e goo d correlatio n wa s establishe d betwee n X-Me t an d Keve x analysi s (se e Figur e 2) , onl y on e i n te n sample s wa s dried , cupped , an d analyze d o n th e Kevex

. Th e X-Me t 

### procedur e continue d i n th e sam e manne r throughou t th e res t o f th e program ; tha t is , 

### sample s wer e brough t i n b y th e fiel d crews , analyze d i n triplicat e i n th e plasti c bag , an d the n archived

. DATABAS

E MANAGEMEN T 

### A databas e managemen t syste m wa s develope d usin g th e Statistica l Analysi s Softwar e supporte d b y th e SA S Institut e Inc. , Gary
, NC

. Screen s wer e designe d t o loo k exactl y lik e th e dat a recordin g forms

. Alon g wit h al l th e analytica l dat a (al l triplicat e measurement s an d 

### associate d Q C samples) , othe r dat a includin g easting , northing , analytica l dat e an d time , 

### sampl e type , instrumen t ID
, an d a uniqu e seria l numbe r fo r eac h sampl e wer e tracke d b y th e management system

. 

### Dat a wer e entere d i n batche s (3 0 sample s pe r batch ) an d a s eac h batc h wa s completed , i t wa s printe d ou t an d 'hand checke d agains t th e dat a recordin g form s fo r entr y 

### errors . Al l change s mad e t o th e databas e wer e tracke d b y a compariso n procedure , an d a printou t o f eac h set o f change s mad e t o the dat a set wa s pu t int o the har d cop y datase t fo r documentatio n purposes

. QUALIT

Y CONTRO L 

### A s th e databas e grew , compariso n plot s wer e periodicall y generate d betwee n th e Keve x an d th $ X-Met s t o asses s th e degre e o f correlation , a s wa s don e wit h th e co 

### calibration , thu s demonstratin g interna l consistenc y withi n th e dat a collectio n effort

. Onc e th e CL P corroborator y dat a wer e available , th e sam e typ e o f correlatio n wa s generated , confirmin g th e accurac y o f th e data

.

2 A t a n averag e deadtim e o f 4 0 percent , thi s equate s t o 28 0 second s acquisitio n tim e pe r sample

. 9

### Th e low-rang e sampl e wa s use d t o calculat e detectio n limit s (discusse d i n sectio n entitle d "PRECISION
, ACCURAC Y AN D DETECTIO N LIMITS " below) , an d th e mid-rang e wa s plotte d i n a contro l char t t o monito r instrumen t stability

. Thes e contro l chart s ar e show n i n Figur e 3

. 

### Ther e ar e notabl e difference s i n th e chart s tha t nee d explanation

. Ther e wer e considerabl y mor e sample s ru n o n X-Me t Numbe r On e tha n o n th e Kevex , thu s th e differenc e i n a horizonta l sense . Ther e wa s onl y on e se t o f QCC S ru n o n th e Kevex; however , ther e wer e a t leas t three set s ru n o n X-Me t Numbe r On e du e t o breakag e o f th e polypropylen e fil m an d los s o f sample

. Wha t wa s no t foreseen , mainl y becaus e th e author s ha d no t engage d i n a n XR F surve y o f thi s magnitude , wa s tha t tim e woul d wrea k havo c wit h th e QCCS

. Th e 0. 2 mi l polypropylen e film , throug h whic h th e sample s ar e X-rayed , 

### develope d smal l hole s wit h tim e an d the soi l leake d out

. Consequently
, the fil m ha d t o b e replace d periodicall y and , bein g highl y electrostatic , i t extracte d portion s o f th e ver y fin e fractio n fro m th e soil , thu s biasin g th e standard

. Occasionally , th e fil m woul d simpl y brea k 

### an d anothe r QCC S woul d hav e t o b e used

. The bia s betwee n th e differen t QCC S sample s coul d b e see n a s severa l distinc t concentratio n groupings , th e firs t brea k bein g a t ru n numbe r 11 7 (fo r X-Me t Numbe r One)

. Al l o f thes e potentia l source s o f erro r manifeste d themselves , particularl y i n th e contro l char t fo r X-Me t Numbe r One , becaus e th e majorit y 

### o f th e sample s wer e analyze d on thi s instrument

. Also , th e QCC S wer e analyze d i n triplicat e o n th e X-Met s an d wer e shake n an d tappe d betwee n eac h measurement

. Th e leas t variabilit y i s eviden t fro m th e Keve x char t because considerabl y fewe r sample s wer e ru n o n thi s instrumen t and sample s wer e run onl y once , thu s muc h les s abus e o f th e polypropylen e fil m occurred

. I n retrospect , th e QCC S shoul d hav e bee n pulverize d an d presse d t o pellets , alleviatin g th e biase s wit h time

. Th e accurac y o f th e X-Me t i s clearl y displaye d i n th e 

### correlatio n betwee n CL P an d X-Me t dat a (se e Figur e 4)

. Ninety-si x o f th e 14 0 sample s sen t t o th e CL P wer e ru n o n X-Me t Numbe r On e (R 2 

### = 0.86)

. C L P VERSU S X-MET s 

### Figur e 4 show s the correlatio n plot s betwee n combine d X-Me t an d CL P an d betwee n th e Keve x an d CLP

. Thes e plot s sho w ver y goo d agreemen t betwee n XR F measurement s 

### an d thos e o f th e CLP
, thu s supportin g th e hig h degre e o f accurac y achieved i n thi s fiel d survey . Th e highe r R 2 

### valu e fo r th e les s sophisticate d X-Met s i s probabl y a resul t o f th e triplicat e measuremen t averag e accountin g fo r th e heterogeneit y o f th e sampl e bette r tha n 

### th e single , longe r measuremen t use d o n th e Kevex

.



### 1 1L

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### ^^ * 1 I ! I ^3 ^' i i i ! ! 0 0. 2 0. 4 0. 8 O J 1. 0 1. 2 1 ICVEXn« M LB* D Mk M h wl » 4 

### Figur e 4

. Correlatio n plo t betwee n CL P an d combine d X-Mets , an d Kevex

. PRECISION
, ACCURAC Y AN D DETECTIO N LIMIT S 

### The syste m precisio n ca n b e estimate d from the mois t fiel d duplicates

. Thes e 

### sample s wer e spli t i n th e fiel d afte r th e i n sit u preparatio n o f th e soil

. Th e samplin g trowe l woul d scoo p alternatel y t o tw o bag s an d eac h sampl e wen t throug h th e syste m i n a n identica l manner . Th e analysi s o f a routin e sampl e an d it s fiel d duplicat e ofte n occurre d i n differen t batches , s o there i s a larg e tim e componen t i n th e overal l variabilit y o f thes e duplicates

. Th e 

### frequenc y distributio n an d univariat e statistic s show n i n Figur e 5 ar e o n th e percent relativ e 

### standar d deviatio n (%RSD
, o r percen t coefficien t o f variation ) betwee n th e routin e sampl e an d it s fiel d duplicat e fo r sample s ove r 0.0 5 wt % (50 0 ppm ) Pb

. A t the 95t h percentile , %RS D i s 27 , s o a ver y conservative estimat e o f precisio n i s ±27%

. This i s no t jus t analytica l erro r bu t include s fiel d samplin g erro r an d sampl e preparatio n error s a s well

. Accurac y ca n b e estimate d fro m th e correlatio n wit h th e CLP

. Wit h a n 88 % 

### correlatio n (Figur e 4, lef t plot) , th e accurac y ca n b e estimate d a t approximatel y ±6 % (hal f o f th e 12 % non-correlation)

.

1

3FREQUENC

Y
22 0
20 0
18 0
16 0
14 0
120
10 0
8 0
6 0
4 0
2 0 *** * *** * »*» * *** « *** * «*» * *** * *** * *** * *** » *** * *** * *** * *** * *»* » *** * *** * *** * *** * *** * *** * *** * **« * *** * *** * *** * *** * *** * *** * *** * *** * **» • *** * *»* * *** * *** * *** * *** * **» » *** * *** • *** * *** * *** « *** * *** * *** * *** * »** * *** * *«* * *** * »** * *** * *** » *** * *** « *** » **» * *** * *** * *** * *** * *** * *** * *** * **» * *** * *** * *»» * *** * *** * *** * **• » *** * *** * *»* * **» * *** * *** * *** * *»* * *** * *•* * *** * *** • *»• * ««* * *** » *«« * **• • *** * *** * *** * «** * 2. 5 7. 5 12. 5 17. 5 Moment s H 53 1 Mea n 8. 8 Varianc e 80. 8 St d De v 9. 0 Skewnes s 2. 1 Kurtosi s 5. 5 Coe f Va r U2. 0 QuantUes(Def>5 ) lOOXMa x 58. 3 99 X 43. 8 75X0 3 11. 9 95 X 26. 8 50 X Ne d 5. 9 90 X 19. 5 25X0 1 2. 6 10 X 1. 0 O X Mi n 0 5 X 0. 5 1 X 0. 1

»** * *** * •»* * **» » *** * •** * »»* * *** » ***

* 22. 5 27. 5 32. 5 37. 5 42. 5 47. 5 52. 5 57. 5 RSO_P B MIDPOIN T Figur e 5

. Frequenc y distributio n o f %RS D fo r mois t fiel d duplicates

.

1 5

### Actio n

Level (ppm ) 

### 50 0 100 0 150 0 200 0 250 0 300 0 

### Fals e

Positiv e 2 (8.7% ) 9 (22.0% ) 1 3 (22.4% ) 2 1 (26.6% ) 1 3 (14.6% ) 8 (8.4% ) 

### Fals e

Negativ e 3 (2.5% ) 2 (2.0% ) 3 (3.6% ) 6 (9.5% ) 4 (7.5% ) 8 (17.0% ) 

### Tabl e 1

. Fals e positive s an d fals e negative s generate d a t si x actio n levels

. POPULATIO N TESTIN G 

### A s explaine d above , residentia l acces s wa s extremel y limite d a t th e beginnin g o f th e fiel d season , s o th e firs t 50 % o r mor e o f 

### th e sample s cam e fro m shoulder s o f alley s i n direc t proximit y wit h 

### residences

. Th e obviou s questio n wa s whethe r th e contaminan t concentration s

alon g th e alleyway s wer e significantl y differen t 

### fro m contaminan t concentration s

i n nearb y residentia l soil s (i.e. , ar e alle y sample s representativ e

o f yar d material?)

. T o answe r thi s question , 3 8 'cells wer e locate d wher e sample s wer e take n 

### bot h withi n alle y rights-of-wa y

an d i n th e nearb y residentia l 

### yards

. Th e paired-sampl e t-tes t an d th e nonparametric

Kolmogorov

- Smirno v procedure s o f th e SA S softwar e wer e use d t o sho w that , wit h ver y fe w exceptions , there i s n o significan t differenc e 

### betwee n contaminan t concentration s

i n th e alley s an d i n th e nearb y yards

. 

### Th e result s o f th e test s o n th e individua l cell s ar e show n i n Tabl e 2

. Th e test result s ar e show n fo r tes t siz e 0.05

. 

### Tw o testin g method s wer e employed , on e a parametri c statistica l approac h (2-sampl e t Test) , th e othe r a nonparametri c 

### statistica l tes t (Kolmogorov-Smirno v

Test)

. Th e tw o approache s wer e trie d becaus e th e distributio n o f dat a value s wa s tendin g toward th e lognormal , bu t no t strongl y so . Thu s i n orde r t o cove r al l th e bases , bot h method s wer e tried

. O f th e 3 8 pairwis e comparison s o f yar d an d nearb y alleywa y samples , fiv e wer e significantl y differen t usin g th e parametri c test , whil e onl y tw o 

### wer e significantl y differen t usin g th e nonparametric

test

. Thi s confirm s th e mor e nearl y lognorma l distributio n

o f values

. Bot h method s poin t t o th e sam e conclusion , tha t th e tw o population s ar e essentiall y th e same . 

### 1

7

### Cel

l Numbe r 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 

### 1 9 

### 2 & t Tes t N S D N S D N S D S D N S D N S D N S D N S D N S D N S D N S D N S D N S D 

### N S D S D N S D N S D 

### N S D N S D N S D K S Tes t N S D N S D N S D N S D N S D N S D N S D 

### N S D N S D N S D N S D N S D N S D N S D N S D N S D N S D N S D N S D 

### N S D Cel l Numbe r 2 1 2 2 2 3 2 4 2 5 2 6 2 7 2 8 2 9 3 0 3 1 3 2 3 3 3 4 3 5 3 6 3 7 3 8 t 

### Tes t N S D N S D N S D N S D 

### N S D N S D N S D N S D 

### N S D N S D S D N S D N S D 

### N S D N S D N S D 

### S D S D K S Tes t N S D N S D N S D N S D N S D N S D N S D 

### N S D N S D N S D S D N S D N S D 

### N S D N S D N S D S D N S D



### Tabl e 2

. Lis t o f result s o f t-tes t an d Kolmogorov-Smirno v

(KS ) test

. "NSD " mean s n o 

### significan t difference , "SD " mean s significan t difference

.

1 9

### REFERENCE S
1

. Tweto , Ogden

. 1968

. Leadvill e District
, Colorado
, i n Or e Deposit s i n th e Unite d 

### States

. 1933/1967

. J.D

. Ridge
, ed

. America n Institut e o f Mining , Metallurgical , an d Petroleu m Engineers

. Ne w York , Ne w York

. pp

. 681-705

. 2

. Unite d State s Departmen t o f Agriculture , Soi l Conservatio n Service
, i n cooperation

. 

### wit h th e Colorad o Agricultura l Experimen t Station

. 1975

. Soi l Surve y o f Chaffee

- Lak e area , Colorad o an d Part s o f Chaffe e an d Lak e Counties

. Unite d State s Governmen t Printin g Office , Washington , D.C

. 

### 3

. Workpla n Soi l Samplin g an d X-ra y Fluorescenc e Analysis , Volum e 1 , Leadvill e 

### Colorado

. Septembe r 1991

. Ro y F

. Weston , Inc

. Denver
, Colorado

. 4

. Jenkins , Ron
, R.W

. Gould
, an d D

. Gedcke

. Quantitativ e X-ra y Spectrometry

. 1981

. 

### Marce l Dekker
, Inc

. Ne w Yor k an d Basel

. 58 6 pages

. 

### 5

. America n Chemica l Society

. 1983

. Principle s o f Environmenta l Analysis

. Analytica l Chemistry
, Vol

. 55

. p p 2210-2218

. 6

. Flatman , G.T.
, E

. Englund
, A

. Yfantis

. 1988

. Geostatistica l Approache s t o th e 

### Desig n o f Samplin g Regimes
, i n L.H

. Keith , ed

. Principle s o f Environmenta l Sampling

. American Chemica l Society
, pp

. 73-84

. 7

. Unite d State s Environmenta l Protectio n Agency

. Marc h 1987

. Dat a Qualit y Objective s fo r Remedia l Respons e Activitie s - Developmen t Process

. EP A 540/G



### 87/003

. Washington , D.C

.

ftUJ

. GOVUNMCN T HUNTIN G OFFIC E IM 1 - 79MK/MM Z 2 1Jul y 28 , 199 3 STATISTICA L COMPARISO N O F LEA D CONCENTRATION

S I N WHOL E AN D FIN E SOI L FRACTION S FRO M CALIFORNI A GULC H (LEADVELLE ) SUPERFUN D SIT E
U.S

. EP A Region YI H Denver
, Colorad o Tas k Lea d W J L Col e an d C.A

. Kuhari c Lockhee d Enviromneota l System s an d Technologie s Co

. La s Vegas , Nevad a A.K

. Sing h ADLInc

. Socorro
, Ne w Mexic o
Technolog y Suppor t Cente r fo r Monitorin g an d Sit e Characterizatio n 

### Environmenta l Monitorin g System s Laborator y U.S

. Environmenta l Protectio n Agenc y 

### La s Vegas , Nevad a 89193-347 8 (702 ) 798-227 0TABL E O F CONTENT S NOTIC E

...................................................... . i TABL E O F CONTENT S

............................................ . i i LIS T O F FIGURE S

.............................................. . ii i LIS T O F TABLE S

................................................ . i v ABSTRAC

T

.................................................... . v INTRODUCTIO

N

................................................ . 1 SUMMAR Y STATISTIC

S AN D RESULT S O F STATISTICA

L COMPARISON

S

........ . 2 F O R LEA D CONCENTRATION

S I N WHOL E AN D FIN E SOI L FRACTION S REFERENCE S

................................................. . 1 2 APPENDI X A

.................................................. . 1 3

uLIS T O F TABLE S Tabl e 1 : Summar y statistics , correlatio n coefficients , . . leas t square s regressio n lines , an d result s o f paire d t-test s fo r lea d concentration s i n fin e an d whol e soil s o f Leadvill e sit e obtaine d fro m Phas e 1 investigation

. Tabl e 2 : Summar y statistics , correlatio n coefficients , . . leas t square s regressio n lines , an d result s o f paire d t-test s fo r lea d concentration s i n fin e an d whol e soil s o f Leadvill e sit e obtained fro m Phas e 2 investigation

.

I

VI

. INTRODUCTIO

N Th e tow n o f Leadville
, Colorad o lie s abou t 10 0 mile s southwes t o f Denver
, Colorado

. Gold
, silver , lea d an d zin c minin g activitie s i n th e vicinit y o f Leadville
, whic h dat e bac k t o th e 185 9 discover y o f place r gol d i n Californi a Gulch
, hav e lef t behind larg e amount s o f slag , min e waste , tailing s an d smelte r emission s containin g lead , zinc , cadmium, arseni c an d othe r metals

. T h e Unite d State s Environmenta l Protectio n Agenc y (USEPA ) conducte d a preliminar y sit e investigatio n h i 1982-83 , whic h resulte d i n th e Leadvill e sit e bein g place d o n th e Nationa l Priorit y Lis t (NPL ) i n 1983

. I n 1991 , a t th e reques t o f Regio n 8 , Environmenta l Monitorin g System s Laborator y a t La s Vega s (EMSL-LV ) assiste d h i conductin g a n intensiv e soi l samplin g an d measuremen t effort

. Utilizin g Fiel d Portabl e X-Ra y Fluorescenc e (FPXRF ) instrument s lea d level s wer e determine d i n ove r 370 0 soi l samples

. Th e dat a obtaine d fro m thes e sample s wer e the n use d t o determin e an d identif y th e spatia l distributio n o f lea d h i th e Leadvill e area . Anothe r goa l o f thi s investigatio n wa s t o demonstrat e th e abilit y o f th e FPXR F instrumentatio n t o generat e quantitativ e dat a o f know n quality

. Th e approac h an d method s use d h i thi s sit e investigatio n ar e addresse d an d identifie d h i a EMSL-L V TS C technica l repor t (USEP A 1993)

. Thi s repor t deal s wit h anothe r aspec t o f th e soi l lea d analysis

. Concer n ha s bee n expresse d tha t onl y th e fin e soi l fractio n i s ingestible , therefor e whol e soi l analysi s yield s invali d dat a fo r assessmen t o f bioavailabl e soi l fraction s a t th e sit e (ASARC O 4/23/92)

. Thi s prompte d th e Regio n 8 Remedia l Projec t Manage r (RPM ) t o initiat e a two-phas e stud y o f lea d concentration s a s a functio n o f soi l siz e fraction

. Th e Phase 1 stud y utilize d 6 8 sample s randoml y selecte d fro m th e Leadvill e soi l sample s whic h wer e archive d followin g th e 199 1 fiel d FPXR F survey . Thes e sample s wer e sieve d an d th e 'less tha n 250/t * soi l fraction s wer e sen t t o th e Universit y o f Colorado
, Boulde r (UCB ) for XR F analysi s on a Keve x 770

. Th e Phas e 2 stud y utilize d 8 6 sample s selecte d fro m 1 6 yard s wher e replicat e sample s ha d bee n obtaine d durin g th e 199 1 fiel d activities

. Th e sample s wer e sieve d an d th e 'les s tha n 250/t * soi l fraction s wer e sen t t o UC B fo r XR F analysis

. T h e analytical result s fro m th e tw o phase s 'o n th e 'les s tha n 250^ soi l fractio n wer e sen t t o EMSL-L V t o compar e t o th e result s previousl y obtaine d b y FPXR F o n th e whol e soil

. Thes e tw o dat a 

### set s ar e show n i n Table s A- l an d A- 2 o f Appendi x A

. Ou t o f th e 6 8 sampl e location s selecte d fo r th e Phase 1 investigation , 4 0 location s wer e collecte d fro m th e edg e o f alle y right-of-way s (alleyways ) an d th e remainin g 2 8 h i residentia l yards , no t necessaril y h i clos e proximit y t o on e another

. Th e soi l sample(s ) populatio n o f mos t interes t wer e thos e collecte d i n th e residentia l yards

. The two subset s o f dat a (alleyway s an d yards ) wer e statisticall y analyzed separately

.Tabl e 1 : Summar y statistics , correlatio n coefficients , least-square s regressio n lines , an d result s o f paire d t-test s fo r lea d concentration s i n fin e an d whol e soil s o f Leadvill e sit e obtaine d fro m Phas e 1 investigation

. Statistica l Metho d Use d Correlatio n an d straigh t lin e fittin g b y method o f leas t square s (LS ) (simpl e linear regression )
Summar y Statistic s an d 95 % Confidenc e Interval * fo r differenc e i n mean s ALLEYWAY

S Numbe r o f paire d sample s n 4 0 (se e Figur e 1 ) Correlatio n Coefficien t r = 0.4 7 L S estimat e o f straigh t line : slop e = 0.5 3 Intercep t = 1474.5 3 % variabilit y explaine d b y L S

= 22.1 % Estimate d mea n differenc e (whole-fine )

= 352. 1 standar d deviatio n o f difference s i n lea d 

### measurement s ( d = whol e - fine ) sd(diff ) = 786.4 3 

### 95 % Confidenc e Interva l fo r 

### differenc e i n mean s (whole

fine )

= (100.79,603.41 ) YARD S Numbe r o f paire d sample s n 2 8 (se e Figur e 2 ) Correlatio n Coefficien t r = 0.9 1 L S estimat e o f straigh t line : slop e = 0.9 4 Intercep t = 840.4 5 % variabilit y explaine d b y L S lineaOOr 2 ) = 82.1 % Estimate d mea n differenc e (whole-fine )

= 352. 5 standar d deviatio n o f difference s i n lea d 

### measurement s ( d = whol e - fine ) sd(diff ) = 1229.7 4 95 % Confidenc e Interva l fo r differenc e i n mean s (whole

fine )

= (-124.38,829.38 )

* I f 0 lie s insid e th e 95 % Confidenc e Interva l fo r differenc e i n means , the n a t tes t siz e a = 0.0 5 th e nul l hypothesi s o f n o differenc e i n mean s i s NO T REJECTED ; i f 0 lies outsid e th e 95 % Confidenc e Interva l fo r differenc e i n means , the n a t tes t siz e a = 0.0 5 th e nul l hypothesi s o f n o differenc e i n mean s i s REJECTED

.500

0 450 0 400 0 350 0 300 0 250 0 200 0 150 0 100 0 i>a i_

_

s_o j o

_ i __•_

_ ! I I ! *«

. »«

M .«^

M .« M » ...........

t .— — .......•«..««••. • O O Q I Fn e lea d
Figur e 1 : Least : square s regressio n lin e fo r ALLEYWAY

S o f Phas e 1 : 

### # Pair s Correl

. Coeff

. Slop e Intercep t 4

0 0.4 7 0.5 3 1474.5 3 1

400

0 Fk w

ta d
Figur e 2 : Leas t square s regressio n lin e fo r RESIDENTIA

L YARD S o f Phas e 1 : 

### # Pair s = 2 8 Correl

. Coeff

. = 0.9 1 Slop e =

0.9 4 

### Intercep t = 840.4 5Whol

e lea d Fn e lea d 

### Figur e 5 : Histogra m fo r whole_lea d fo r Phas e 1 (ALLEYWAYS) : 

### Figur e 6 : Histogra m fo r fine_lea d fo r Phas e 1 (ALLEYWAYS) : Mea n s d Minimu m 25t h % Media n 75t h % Maximu m 2739. 4

805. 2 139 0 213 3 2763. 5 321 7 486 7 Mea n

s d 

### Minimu m 25t h % Media n 75t h % Maximu m -

2387. 3

= 708. 2

= 113 5

= 174 6

= 241 7

= 282 4

= 382 5I

t ca n b e see n fro m Tabl e 1 that a t th e 95 % confidenc e leve l (tes t siz e a = 0.05) , th e nul l hypothesi s o f n o differenc e i n mean s o f lead concentration s h i whol e an d fin e soil s i s REJECTE D FO R ALLE Y EDGE S (ALLEYWAYS)
,

an d NO T REJECTE D FO R YARDS o f Leadville

. I n othe r words , w e ca n conclud e tha t w e ar e 95 % certai n tha t th e mean s o f lead concentration s i n whol e soi l fraction s a n d fin e soi l fraction s ar e SIGNIFICANTL

Y DIFFEREN T FO R ALLE Y EDGE S (ALLEYWAYS

) an d N O T SIGNIFICANTL

Y DIFFEREN T FO R YARDS

. However , th e mea n lea d concentration i n whol e soi l fraction s appear s t o b e highe r tha n th e mea n lead concentratio n i n fin e soi l fractions , an d henc e th e mea n lea d concentratio n h i whol e soi l fraction s ca n b e viewe d a s a conservative estimat e fo r th e mea n lead concentratio n i n fin e soi l fractions

. Th e result s h i Tabl e 2 sho w tha t a t 95 % confidenc e leve l (tes t siz e a = 0.05) , th e nul l hypothesi s o f n o differenc e h i mean s o f lea d concentration s h i whol e an d fin e soil s i s NO T REJECTE D fo r Phas e 2 data

. I n othe r words , w e ca n conclud e wit h 95 % certaint y tha t there i s n o differenc e h i mean s o f lea d concentration s hi whol e soil-fraction s an d fin e soi l fraction s fo r Phas e 2 data

. 

### Table s 1 an d 2 als o sho w that : (1 ) the distribution s o f the difference , d , Qea d i n whol e soi l fractio n minu s lea d hi fin e soi l fraction ) fo r residentia l yard s o f Phase 1 an d Phase 2 investigations are quit e different

. Thi s differenc e h i distribution s ma y b e du e t o th e muc h highe r lea d concentration s an d large r standar d deviatio n (sd ) o f d fo r th e Phas e 1 residentia l yards

. (2 ) th e size s o f th e 95 % confidenc e interval s fo r th e differenc e h i mean s o f lea d concentration s h i whol e an d fin e soi l fraction s are : • 502. 6 mg/k g fo r ALLE Y EDGE S (ALLEYWAYS

) o f PHAS E 1 • 953. 8 mg/k g fo r YARD S o f PHAS E 1 • 273. 1 mg/k g fo r PHAS E 2 (AL L YARDS)
, showin g ma t th e dat a fro m Phase 2 ar e mor e reliabl e tha n Phas e 1 data

. 

### (3 ) h i bot h phase s o f th e investigation , ther e i s goo d correlation betwee n lea d concentration s h i whol e soi l fraction s an d fin e soi l fraction s fro m residentia l yard s o f Leadville

. Ideally , fo r goo d agreemen t h i lea d measurement s h i whol e an d fin e soi l fractions , th e slop e o f th e lin e shoul d b e clos e t o 1 an d th e intercep t o f th e line close t o 0

. Fo r th e tw o investigation s o f residentia l yards , th e slope s rang e fro m 0.8 0 t o 0.94 , 

### bu t th e intercept s ar e no t clos e t o zero . Th e intercept s probabl y reflec t th e tendenc y o f th e whol e soi l fractio n t o overestimat e th e lea d result s o f th e fin e soi l fraction

. O n th e basi s o f stron g correlations , slope s nea r 1. 0 an d n o significan t differenc e fo r paire d dat a fro m residentia l yards , th e lea d concentration s i n whol e soi l fraction s ca n b e use d t o predic t lea d concentration s h i fin e soi l fraction s h i Leadville

.

1 1APPENDI X A Lea d concentration s i n fin e an d whol e soi l fraction s fro m Phas e 1 an d Phas e 2 investigation s

1 3Lea d

concentration s i

n fin e an d whol e soi l fractions : Phas e 1 Dat a (Continue d fro m previou s page ) Sampl e I D Fine_P b Locat

. Eastin g 34440.0 0 35030.0 0 35064.0 0 35069.0 0 35075.0 0 35092.0 0 35098.0 0 35106.0 0 35130.0 0 35145.0 0 35190.0 0 35200.0 0 35205.0 0 35229.0 0 35241.0 0 35243.0 0 35244.0 0 35307.0 0 35344.0 0 35444.0 0 35608.0 0 8633.0 0 10453.0 0 10596.0 0 7415.0 0 7881.0 0 7309.0 0 5405.0 0 9586.0 0 6380.0 0 5470.0 0 5716.0 0 8038.0 0 7799.0 0 6280.0 0 7963.0 0 9586.0 0 6770.0 0 6884.0 0 7150.0 0 9075.0 0 6057.0 0 Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y 1776787.0 0 1774362.0 0 1777865.0 0 1777937.0 0 1777277.0 0 1778363.0 0 1777319.0 0 1776691.0 0 1778710.0 0 1776208.0 0 1775163.0 0 1774152.0 0 1773443.0 0 1775822.0 0 1775465.0 0 1775462.0 0 1775459.0 0 1778143.0 0 1778577.0 0 1775117.0 0 1769448.0 0 Northin

g Whole_p b 517138.0 0 514845.0 0 515694.0 0 515599.0 0 518431.0 0 515251.0 0 515898.0 0 515551.0 0 516853.0 0 514663.0 0 514204.0 0 514380.0 0 514252.0 0 518138.0 0 515082.0 0 515126.0 0 515112.0 0 516746.0 0 517317.0 0 517336.0 0 512284.0 0 8723.0 0

8203.0 0 100.0 0 6383.0 0 7197.0 0 7990.0 0 6600.0 0 8807.0 0 6967.0 0 6480.0 0 7270.0 0 7243.0 0 8013.0 0 7003.0 0 8037.0 0 8173.0 0 7220.0 0 8313.0 0 8550.0 0 7850.0 0 6637.0 0



### 1 5

### Lea d

concentrations

i n fin e an d whol e 

### Dat a (continue d fro m previou s page ) Locatio n Whole_P b Fine_P b SAM_I D 42 7 42 7 42 9 42, 9 42 9 42 9 42 9 42 9 42 9 52 3 52 3 52 3 52 3 52 5 52 5 52 5 52 5 52 5 52 5 61 7 61 7 61 7 61 7 61 7 61 7 61 7 61 7 618 61 8 61 8 61 8 61 8 80 0 80 0 80 0 80 0 80 0 80 0 80 0 316

7 183 7 377 3 127 3 429 0 1423 136 7 119 0 242 7 139 0 276 0 335 3 150 7 376 3 423 7 423 3 486 7 108 3 425 7 214 7 169 3 470 0 235 3 394 7 287 3 248 0 247 0 207 3 316 3 1400 206 3 498 3 377 3 169 0 9 3 129 0 249 0 135 7 105 3 270 0 170 0 340 0 120 0 410 0 380 0 160 0 87 6 260 0 150 0 320 0 360 0 130 0 400 0 380 0 370 0 510 0 56 7 440 0 330 0 170 0 380 0 300 0 470 0 330 0 110 0 250 0 240 0 350 0 110 0 1700 570 0 260 0 190 0 16 2 88 2 240 0 84 1 160 0 3388 6

3388 7 3421 3 3421 4 3421 5 3421 6 3421 7 3421 8 3421 9 3405 6 3405 7 3405 8 3405 9 3532 6 3532 7 3532 8 3532 9 3533 0 3533 1 3410 3 3410 4 3410 5 3410 6 3410 7 3410 8 3410 9 3411 0 3415 3 3415 4 3415 5 3415 6 3415 7 3391 7 3391 8 3391 9 3392 0 3392 1 3392 2 3392 3 soi l fractions : Phas e 2 Eastin g Northin

g 1777544.0 0 1777553.0 0 1774569.0 0 1774551.0 0 1774557.0 0 1774533.0 0 1774512.0 0 1774502.0 0 1774516.0 0 1778368.0 0 1778358.0 0 1778385.0 0 1778372.0 0 1777997.0 0 1778019.0 0 1778005.0 0 1778056.0 0 1778056.0 0 1778089.0 0 1773736.0 0 1773725.0 0 1773700.0 0 1773706.0 0 1773723.0 0 1773737.0 0 1773706.0 0 1773741.0 0 1778411.0 0 1778378.0 0 1778450.0 0 1778421.0 0 1778381.0 0 1773170.0 0 1773141.0 0 1773130.0 0 1773135.0 0 1773101.0 0 1773105.0 0 1773106.0 0 517731.0 0

517710.0 0 514076.0 0 514081.0 0 514099.0 0 514112.0 0 514093.0 0 514068.0 0 514038.0 0 516132.0 0 516107.0 0 516084.0 0 516050.0 0 517302.0 0 517287.0 0 517258.0 0 517242.0 0 517273.0 0 517274.0 0 514173.0 0 514144.0 0 514151.0 0 514141.0 0 514125.0 0 514107.0 0 514096.0 0 514081.0 0 517501.0 0 517521.0 0 517543.0 0 517607.0 0 517575.0 0 513790.0 0 513793.0 0 513815.0 0 513853.0 0 513844.0 0 513800.0 0 513870.0 0

1 7