COMPANY OF AGVIEROCAP.O. BOX 3567

DAVENPORT, JOWA 52808

359-2QQO

August 29, 1996

James ColbertEPA Region VIIIowa-Nebraska Remedial Branch726 Minnesota Ave.Kansas City, Kansas 66101

RE: Unit Grouping - Former Foil Mill Underground Storage Tanks (HU-13) and Foil MillUnderground Storage Tanks OPF-OP

Dear Jim:

After review of soil and groundwater analytical data from the Former Foil Mill UndergroundStorage Tanks (Unit HU-13) and Foil Mill Underground Storage Tanks ( Unit IPF-01), werecommend grouping these units for preparation of the Risk-Based Concentration Report. Wewould call the combination the Foil Mill USTs Unit Group. This recommendation is based onthe facts that Units HU-13 and IPF-01 are almost adjacent to each other; they have similarconstituents of interest; similar anticipated exposure scenarios; similar surface and subsurfacecharacteristics and both units are locations from which Foil Mill underground storage tanks(USTS) were removed. At the time of the Facility Site Assessment, Unit IPF-01 was thelocation of active Foil Mill USTS; hence, the classification as an Industrial Process Unit.These tanks were removed in 1992.

In addition to the technical reasons cited above, other incentives exist for addressing these twounits as a group. By grouping units, use of available analytical data for the area is maximizedand evaluation of risk-based scenarios at each unit can proceed at an accelerated pace andhasten implementation of remedial alternatives, if necessary. A data package for the proposedFoil Mill USTs Unit Group is enclosed. This package includes data Tables 2-1 through 2-5and unit location Figure 2-2.

If you have any questions or comments, please call.

Yours truly,

cc: Bud Sturtzer (e-mail)

Marshall SonksenRemediation Manager

823• ' ' '. " !" i •- f" • t • + ~» •?

.+ _ .... _ .. i... _ ..i 4 - j . .!. „ '.....

PAVE

T : - ~ i 7" . : : 1 : jI ,' !..._/.. .' + i i H 1 " ~"

: I f : : : ;_

EXPLANATION

IPF-01 FOIL MILL USTs

IPF-03 FOIL MILL SCRAP METAL BALERS

IPF-04 FOIL MILL PLAIN METAL ROLLINGAREA

HU-13 FORMER FOIL MILL USTs

GERAGHTY& MILLER, INC.

Envi-nmrrwTttal Senicas

DRAWING CONFIDENTIAL: THS MunNCAND AU. HFORUAT10N CONTAINED FHCRCDN ISAND SHIU ROMH THE POOPCRTV Of COUCKTVft UU£R. INC. AS AN IHSTRUUENT Of PROFES-SIONAL SEMCE. THIS INFTJRUATDN 91ALL NOTBE USED N WHOLE OR IN PART HTHOUT THEfULL KNOIKLEKE AND PRXW WHTTEN CONSENTOF CdUCHTT t MILD), HC.

SCALE VERinCATlON

TUB a« REPRESENTSONE HCH ON FHEonawL nu»K:

USE TO VERTY F10URCREPRODUCTION SCALE

OftUMC: JLOHVJIITR1C I PLOT SZE: -

gWTCO BT. K13OCOCED 9* A.W. LOCATION OF FOIL MILL TANK UNIT

GROUP AND SURROUNDING FSA UNITS

FIGURE

2-2

1 QMFM-HO ; "'"GMFM-10CN)

R-01R-OKN)RW-1RW-KN)

R-02 v , •RW-2 \ \ \RW-2(M) \ \

QMFM-07.2QMFM-07JUIOQMFM-07

QMFM-OB.UN)QMFM-08.KW)GMFM-08 \QMFM-OB(N)

QMFM-06.3OMFM-06.3<N)OMFM-08OMFM-OeOU

QMFH-0«:3QMF»-09QMFM-Oe -,QMFHH}9(N) : -QMFM^OgCWQMFU-090UP

INVESTIGATION

DRAWING CONFIDENTIAL THS DRUtwoAND AU. nrORMATCOK COKTAHEO THEREM ISAND SHALL REMAIN THE PROPERTY OF CCRACHTYft U1UR. INC. AS AM INSTRUMENT OF PROFE5-SOMH. SCRVCE. THIS nrORUATION SHALL NOTBE USED W WHOLE OR IN PART WTTKVT THEFUU. KNOWLEDGE AND PRIOR WRITTEN CONSENTOF CERACHTY ft ULLER. INC.

GERAGHTY& MILLER, INC.

Environmantai Services

LOCATIONS OF MONITOR WELLSAND SOIL SAMPLES AT

FOIL MILL TANK UNIT GROUP

Table 2-1. Review of Data Useability Criteria for Risk Assessment, Foil Mil l Tank Unit Group, Alcoa-Davenport Works, Riverdale, Iowa.

Investigation

Leaking UST Site Assessment Report (G&M1991)

Soil

Groundwater

Findings of the Foil Mill HydrocarbonInvestigation (G&M 1993)

Soil

Soil Vapor

Groundwater

Leaking Underground Storage Tank SiteMonitoring Report (November 1995)

Groundwater

,

£ §c -2

Incl

uded

ied

Calc

uli

i/t£ «« 09Q

YES

YES

no

no

YES

YES

3cq

E

ourc

es C

o

y>a«

YES

YES

YES

no

YES

YES

co

ocum

enta

Com

plet

e

a

YES

YES

YES

YES

YES

YES

| =

« 1 I•s 8 2? ac

YES

YES

YES

YES

>

YES/

/

\\

YES

>,

"o•o

•£ -o1 |no 3ea.Ea.

YES

no

YES

^^

\\

\

\. no x

Data Quality Indicators Satisfied

y.c

w'o.EoU

YES

YES

YES

YES

\

£ES

"̂̂

y

^^

>YES

fr

sesQ.

OU

YES

YES/

\

\\

YES

no

YES

xf

YES

C<u

a '

iat

YES

^>v^

YES

\\\/

YES

\

\ES/V

YES

YESP

reci

sion

YES

"Y6S^

'

/ "/YES

\XYES

YES

YES

Acc

urac

}

/\

\

YES

YES

"̂ x./

"*+/

YES

YES

YES

YES

/ ^

a

e ii!

\\

YES\

YES

YES

YES

YES

YES

/ \

\s \ \\// Comments

/̂

\Samples selected based on highest head-space concentration and visual inspectionSamples GMFM-7A, 701NE and R-l were also finger-printed for hydrocarbonsinsufficient amount of sample was collected for R-l .

Results of soil analyses were not included in the data set because soil sample locationare not within the investigative area.

Results will be used qualitatively in RBC report.

Samples from wells GMFM-13, GMFM-14 and the production well (PW-5) will not bused in the RBC report because they are not located within the investigative area.

Samples FM-06, FM-08 and GMFM-I4(N) were not included in the data set becausethey are not located within the investigative area.

Adapted from "Guidance for Data Useability in Risk Assessment", EPA 1992.

GERAGHTY & MILLER. INC.

Page 1 of2

Table 2-2. Determination of Constituents of Interest in Subsurface Soil, Foil Mil l Tank Unit Group, Alcoa-Davenport Works, Riverdale, Iowa.

Constituent

VOLATILE ORGANIC

1,1,1 -Trichloroethane

FrequencyDetects/Total

COMPOUNDS Cmg/kgl

0 / 41,1,2,2-Tetrachloroethane 0/41 , 1 ,2-Trichloroethane1,1-Dichloroethane1,1-Dichloroethene1,2-Dichloroethane1,2-Dichloroethene1 ,2-Dichloropropane2-Butanone2-Hexanone4-Methyl-2-pentanoneAcetoneBenzeneBromodichloromethaneBromoformBromomethaneCarbon disulfideCarbon tetrachlorideChlorobenzeneChloroethaneChloroformChloromethanecis- 1 ,3-dichloropropeneDibromochloromethaneEthylbenzeneMethylene chlorideStyreneTetrachloroetheneToluene

0 / 40 / 40 / 40 / 40 / 40 / 40 / 40 /40 / 40 / 40 / 50 / 40 / 40 / 40 / 40 / 40 / 40 / 4§l/f -\

/0/4 \/0<O\

\°^\y >\/5N/ /

0\4 /

0 / 40 / 5

Range of SOLsMin - Max

0.0050-3.100.0050-3.100.0050-3.100.0050-3.100.0050-3.100.0050-3.100.0050-3.100.0050-3.100.0500-310.0500-31 \0.0500-310.0500-31

0.0050 - 2.50

0.0100-6.20\ 0.0050-3.10/ 0.0050-3.10

0.0050- 1.000.0050-3.100.0050-3.100.0050-3.100.0050-2.50

BenchmarkRegion I X P R G ( i )

30002.4 /\3.3 / /

300Q/ C/0.082\0.98 \270 \

/\"'5

> V\ NA\

\ / 8400

\ \ 3'2

\ / 3'4

^ 24057521.1570

2700I . I4.31.22369025

220025

2800

Percent SOJ^fexceedingBeKchmark

</\\w\/

^ 50%

/\ 0%

y 0%/ 75%\ 50%/ 0%

^ 50%0%

NA0%0%0%0%0%0%0%

50%0%0%

50%•50%50%0%0%0%0%0%0%

r.FRAr.HT

Retainas COI?

noYESnonononononono

YESnononononononononononononono

YESnononono

' Y ^ M H . t

[note]

NSNNWWNWNBNNNNNNNWNNWWWNDNNNN

FR IMPFootnotes appear on page 2.

Page 2 of 2

Table 2-2. Determination of Constituents of Interest in Subsurface Soil, Foil Mill Tank Unit Group, Alcoa-Davenport Works, Riverdale, Iowa.

Constituent

trans- 1 ,3-dichloropropeneTrichloroethene

Vinyl acetateVinyl chlorideXylenes (total)

PCBs (mg/kgj

Aroclor-1016Aroclor-1221Aroclor-1232Aroclor-1242Aroclor-1248Aroclor-1254Aroclor-1260

FrequencyDetects/Total

0 / 30 / 40 / 40 / 43 / 5

0 / 40 / 40 / 40 / 40 / 40 / 40 / 4

Range of SOLsMin - Max

0.0050-3.100.0050-3.100.0500-31

0.0100-6.200.0050 - 0.7400

0.0800 - 0.09500.0800 - 0.09500.0800 - 0.09500.0800 - 0.0950 (0.0800-0.0950 ^0.1600-0.19000.1600-0.1900

BenchmarkRegion IX PRG (l)

1.217

1000000.011 S\990 / // //

\65 \

0.34 \S**̂ ^

\^ O^^yy \/ /$3y\ S ^S*'

\ / 19

\ \ °-34

Percent SQKs^ceedingBenchmark

/ 67^\/ \0% \

N,/75%^

> 0%^\

/

/ 0%' 0%

0%0%0%0%0%

Retainas COI?

nonono

YESYES

nonononononono

[note]

WNNSD

NNNNNNN

Concentrations are reported in milligrams per kilogram (mg/kg^c

(1) EPA Region IX PRGs for industrial soil (EPA 1995b).(a) No Region IX PRG is available for this constituent. Surrogi

SQLs for 2-methylnaphthalene were compared to the benchmarkSQLs for 3-nitroaniline and 4-nitroaniline were comparedSQLs for acenaphthylene, benzo(g,h,i)peiyjene, and phenantl

Notes: B - Retained as a COI because theD - Retained as a COI becauseN - Eliminated as a COI becaS - Retained as a COI becauseT - Eliminated as a COI becauseW - Eliminated as a COI based

been assigned as follows:naphthalene,

chmark for 2-nitroaniline,were compared to the benchmark for pyrene.

ark value for comparison to the SQLs.pted in at least one sample.t detected and less than 20 percent of the SQLs exceed the benchmark values,f the SQLs exceed the benchmark values,

fty is low relative to other retained COIs at the unit (EPA, 1995a).selection of site-wide COIs (Geraghty & Miller 1995a).

COI - Constituent of interest.NA - Not available.PRG - Preliminary remediation goal.SQL - Practical sample quantitation limit for the non-detects.

GERAGHTY & MILLER, INC.

Page 1 of 3

Table 2-3. Determination of Constituents of Interest in Groundwater, Foil Mi l l Tank Unit Group, Alcoa-Davenport Works, Riverdale, Iowa.

Constituent FrequencyDetects/Total

Range of SQLsMin - Max

BenchmarksRegion IX PRG(l) MCL

Percent SQKs ExceedingBoth^Benchmarks

Retainas COI? [note]

VOLATILE ORGANIC COMPOUNDS (me/1) \/\ N.

1,1,1-Trichloroethane1 ,1 ,2,2-Tetrachloroethane1 , 1 ,2-Trichloroethane1,1-Dichloroethane1,1-Dichloroethene1,2-Dichloroethane1,2-Dichloroethene1 ,2-Dichloropropane2-Butanone2-Hexanone4-Methyl-2-pentanoneAcetoneBenzeneBromodichloromethaneBromoformBromomethaneCarbon disulfldeCarbon tetrachlorideChlorobenzeneChloroethaneChloroformChloromethanecis-l,3-dichloropropeneDibromochloromethaneEthylbenzeneMethylene chlorideStyrene

0 / 80 / 80 / 80 / 80 / 80 / 81 /80 / 81 / 80 / 81 / 80 / 8I / 100 / 80 / 80 / 80 / 80 / 82 / 80 / 8

1/J8- — \,078 >

/0^8"~>\<( 0/^8, J\5 / 10 N/ s

0X8 /0/8\X

0.0050 - 0.05000.0050 - 0.05000.0050 - 0.05000.0050 - 0.05000.0050 - 0.05000.0050 - 0.05000.0050 - 0.05000.0050 - 0.05000.0100-0.50000.0100-0.50000.0100-0.50000.0100-0.50000.0020-0.10000.0050 - 0.05000.0050-0)8500,0100- 0.10)00

/o.cxfo)) o.oW^^O.OOS^NM^OO/

(xooso -Xpsfroo.ohjo - Q<IOOO0.0050M).0500

\ 0.0100-0.1000\ 0.0050 - 0.0500} 0.0050 - 0.0500

' 0.0020 - 0.05000.0050 - 0.05000.0050 - 0.0500

1.30.0000550.00020

0.810.000046 <

0.000120.055

0.00016S*+*̂ ^

\ V"**"**

\ O.M039\ O.p0018

V0.00850.0087

0.0210.000170.0390.71

0.000160.0015

0.0000810.0010

1.30.0043

1.6

0.20

NX\0<0050/

/ \\//^\ 0.0070 /

0^050 \

0.̂ 0 y

0.0050^

NAv. NA/ NA

NA0.0050

0.100.10NANA

0.0050NANA0.10NANA0.100.70NA0.10

\y100%50%

> 0%50%50%

> 0%50%0%

NA0%0%

33%0%0%

100%25%50%33%0%0%

100%100%

0%0%

100%0%

no

YESnono

YESYESYESno

YESYESYESno

YESnonono

YESYESYESno

YESYESnono

YESYESno

NSWNSSDWDBDNS,DNNWSS

S,DNDSWNDSN

Footnotes appear on page 3.GERAGHTY & MILLER, INC.

Page 2 of 3

Table 2-3. Determination of Constituents of Interest in Groundwater, Foil Mill Tank Unit Group, Alcoa-Davenport Works, Riverdale, Iowa.

Constituent

TetrachloroetheneToluenetrans- 1 ,3-dichloropropeneTrichloroetheneVinyl acetateVinyl chlorideXylenes (total)

PCBs (mg/1)

Aroclor-1016Aroclor-1221Aroclor-1232Aroclor-1242Aroclor-1248Aroclor-1254Aroclor-1260

FrequencyDetects/Total

0 / 8

O/ 100 / 71 / 80 / 50 / 86/ 10

0 / 5' 0 /50 / 50 / 51 / 50 / 50 / 5

Range of SOLsMin - Max

0.0050-0.05000.0020 - 0.50000.0050 - 0.05000.0050 - 0.05000.0100-0.50000.0100-0.10000.0020 - 0.0050

0.0005 - 0.00200.0005 - 0.00200.0005 - 0.00200.0005 - 0.00200.0005-0.00100.0010-0.00500.0(Htr~OX050

BenchmarksRegion IX PRG(l) MCL

0.00110.72

0.0000810.0016

370.000020

1.4 <

X">eQ26/ ,00000()8>^\ 6^00087\ o.oopefoTT^\ O.OM0087\ Q.MQ13V&000087

0.00501.0NA

0.005Q

r)yt).0020V\{ 1(T /

V0.00050

\0-00050^.00050

0.000500.000500.000500.00050

Percent SQJ« ExceedingBoth^BencJmiarks

/ 50°XXy/V 0% \.ioe% y

57%V0%

100%0%

>

0%60%60%60%50%

100%100%

Retainas COI?

YESnono

YESno

YESYES

nononono

YESYES

no

[note]

SNWS,DNSD

NWWWS,DSW

Footnotes appear on page 3. GERAGHTY & MILLER. INC.

Page 3 of 3

Table 2-3. Determination of Constituents of Interest in Groundwater, Foil Mi l l Tank Unit Group, Alcoa-Davenport Works, Riverdale, Iowa.

Concentrations are reported in milligrams per liter (mg/l).

(l) EPA Region IX PRGs for tap water (EPA 1995b). .** Action level.

Notes: B Retained as a COI because there was no benchmark value for comparison to the SQLs.D Retained as a COI because constituent was detected in at least one sample.N Eliminated as a COI because constituent was not detected and less than 20 percent of the SQLs exS Retained as a COI because 20 percent or more of the SQLs exceed the benchmark values.T Eliminated as a COI because constituent toxicity is low relative to other retained COIs at the urilt (W Eliminated as a COI based on results of the selection of site-wide COIs (Geraghty & Miller<(995a)."X Eliminated as a COI based on the relative percentage of SQLs exceeding the benchmarks and ejiminati

COI - Constituent of interest.MCL - Maximum contaminant level (EPA 1995c).NA - Not available.PRG - Preliminary remediation goal.SQL - Sample quantitation limits for the non-detects.

GERAGHTY & MILLER. INC.

Page 1 of 1

Table 2-4. Determination of Constituents of Potential Concern and Exposure Point Concentrations for Subsurface Soil, Foil Mill Tank Unit Group, Alcoa-Davenport Works,Riverdale, Iowa._ /\ __ __

VOLATILE ORGANIC COMPOUNDS Cms/kg*)

1,1,2,2-Tetrachloroethane

2-Hexanone

Ethylbenzene

Vinyl chloride

Xylenes (total)

0/40/42/50/43/5

NDND

2.30-6.20

ND11-91

2.4NA690

0.011990

1.739

1.685 <0.0050-<3.10 ~

3.370 <0.0100-<6.20 ~

Concentrations are reported in milligrams per kilogram (mg/kg).

(1) EPA Region IX PRGs for industrial soil (EPA 1995b).(2) UCLs are calculated using a normal distribution. UCLs are only calculated when t~ Not detected, but retained as a COPC because SQLs exceeded the benchmark valu# In non-detect samples for which half the sample quantitation limit (the default pro

the maximum detected value was substituted as the proxy concentration in calculatin(a) No Region IX PRO is available for this constituent. Surrogate PRO values have beerkassign

SQLs for 2-methylnapthalene were compared to the benchmark for naphth: "SQLs for 3-nitroaniline and 4-nitroaniline were compared to the benchmarlSQLs for acenaphthylene, benzo(g,h,i)perylene, and phenanthrene were coi

imples is greater than two.is presented as the EPC.ded the maximum detected concentration,

itroaniline,to the benchmark for pyrene.

Notes: B - Retained as a COPC because there was no benchmark valufe for comparison to the SQLs.D - Retained as a COPC because constituent was/detecjeTKat a Concentration exceeding the benchmark value in at least one sample.L - Detected, but eliminated as a COPC because all d^ecjed concentrations were below the benchmark value.P - Eliminated as a COPC based on process knbwledge\S - Not detected, but retained as a COPC becauseSZO percW^njeffe of the SQLs exceed the benchmark value.

COPCEPCNDPROUCL

Constituent of potential concern.Exposure point concentration for theNot detected.Preliminary remediation goal.Upper 95 percent confidnece nrferv

s; lesser of the U^L and the maximum detected concentration.

e meaV using proxy concentrations for the non-detects.

GERAGHTY & MILLER. INC.

Page 1 of 2

Table 2-5. Determination of Constituents of Potential Concern and Exposure Point Concentrations for Groundwater, Foil Mill Tank Unit Group, Alcoa-Davenport Works,Riverdale, Iowa.

ConstituentBenchmarks

FrequencyDetects/Total

Range of DetectsMin - Max

Region IXPRG (l) MCL

Retainas COPC? [note] UCL(2) EPC

VOLATILE ORGANIC COMPOUNDS (mg/11

1,1,2,2-TetrachIoroethane1,1-Dichloroethene

1,2-Dichloroethane

1,2-Dichloroethene

2-Butanone

2-Hexanone4-Methyl-2-pentanone

BenzeneCarbon disulfide

Carbon tetrachloride

ChlorobenzeneChloroform

Chloromethane

EthylbenzeneMethylene chloride

Tetrachloroethene

Trichloroethene

Vinyl chloride

Xylenes (total)

PCBs (mg/n

Aroclor-1248

Aroclor-1254

0.0000087 0.00050

0.00073 0.00050

YESYES

DS

\/

0.009

0.009

0.009

0.0290.009

0.009

0.009

0.0134.295

0.003

0.001

0.0150.0150.015

0.063

0.015

0.0150.015

0.023

11.393

0.007

0.002

<0.0050-<0.0500

<0.0050-<0.0500

<0.0050-<0.0500

0.063

<0.0050-<0.0500

<0.0050-<0.0500<0.0050-<0.0500

<0.0100-<0.1000

11.393

0.007

<0.0010-<0.0050

Footnotes appear on page 2.GERAGHTY & MILLER, INC.

Page 2 of 2

Table 2-5. Determination of Constituents of Potential Concern and Exposure Point Concentrations for Groundwater, Foil Mill Tank Unit Group, Alcoa-Davenport Works,Riverdale, Iowa.

Concentrations are reported in milligrams per liter (mg/l).

(1) EPA Region IX PRGs for tapwater (EPA 1995b).(2) UCLs are calculated using a normal distribution. UCLs are only calculated when the number of samples is greater thanl** Action Level.- Not detected, but retained as a COPC because SQLs exceeded the benchmark values. The range of SQLs is presented as the EPC.# In non-detect samples for which half the sample quantitation limit (the default proxy concentration) exceede^tn\maximum detected concentration,

the maximum detected value was substituted as the proxy concentration in calculating the mean and UCL,

Notes:

COPCEPCMCLNANDPROSQLsUCL

B - Retained as a COPC because there was no benchmark value for comparison to the SQLsD - Retained as a COPC because constituent was detected at a concentration exceeding the behchmark\alues in at least one sample.L - Detected, but eliminated as a COPC because all detected concentrations were below the benchmark vajues.P - Eliminated as a COPC based on process knowledge.S - Not detected, but retained as a COPC because 20 percent or more of the SQLs exceed the benchntefk values.X - Eliminated as a COPC based on process knowledge, low potential for tpdnsper^to groundwater and the fact that the constituent was

not detected in soil.

Constituent of potential concern.Exposure point concentration for the COPCs; lesser of the UCL and the maxMaximum contaminant level (EPA 1995c).Not available.Not detected.Preliminary remediation goal.Sample quantitation limits for the non-detects.Upper 95 percent confidence interval on the mean, usipg" proxy concentrations for the non-detects.

ncentration.

GERAGHTY & MILLER. INC.