JANUARY 30, 1995

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION Vn 726 MINNESOTA AVENUE KANSAS CITY KS 66101

ATTN GLENN CURTIS REMEDIAL PROJECT MANAGER

RE DES MOINES TCE SITE - DICO, INC CONFIRMATION AIR SAMPLING RESULTS PROPOSED OPERATION & MAINTENANCE PRACTICES

JA:I 0 \ ' ^^

SPFD BRANCH

Dear Mr. Curtis;

Enclosed (Attachment A) are the analytical results for the air confirmation sampling performed at the DICO, Inc. facility in Des Moines, Iowa. The sampling was undertaken as required by the administrative order governing the remedial activities in Operable Unit 4.

As the sample results show, values for several of the clean-up parameters are still in exceedance of the limits set forth in the administrative order. Specifically, the levels of aldrin and dieldrin were above the limits in all buildings sampled and the levels of heptachlor were high in Building No. 1, Building No. 4 & No. 5, and the Maintenance Building. Of these samples, only the parameter aldrin exceeded the clean-up levels by more than one order of magnitude. All other parameters did not exceed the clean-up levels

Titan Wheel maintains that even though the analytical resuhs did not, in all cases, meet the requirements set forth by the administrative order, the level of airborne contaminants in the buildings do not represent a health risk to workers in an occupational environment. Justification for this assertion is provided in Attachment B, a risk evaluation provided by O'Brien & Gere Engineers, Inc.

It should be noted that the extreme limits set by the EPA were barely passed by the outside air. Titan believes the EPA should review the limits for the buildings interior and approve these buildings for use. The local Des Moines hospitals would not pass the current limits being applied to the DICO facility

In order to satisfy the agencies concern for potential health risk associated with the levels of airborne contaminants. Titan Wheel proposes to take the following actions.

1.0 Incorporate into the Operating & Maintenance Plan requirements for ventilating the

30221121

Superfund

2701 SPRUCE STREET. QUINCY, ILLINOIS 62301 USA

TELEPHONE: (217) 228-6011. FAX: (217) 228-9871

buildings on a weekly basis. The requirement will stipulate that all functioning doors, overhead doors, and windows will be left open for a period of four consecutive hours per week. In most cases, this ventilation period will take place on weekends to avoid interference with plant operations. Furthermore, authority will be given to the plant engineer to bypass this requirement in the event weather conditions may prove hazardous to the buildings and/or their contents. This action will prevent potential airborne contaminants from accumulating in any areas of the building.

2.0 Perform another set of air confirmation sampling in approximately one year to ascertam if airborne contaminant levels have been reduced to levels acceptable to the EPA. This proposed sampling event will involve the collection of two discreet samples that will be analyzed for pesticide levels only. The two sample locations will be in the Maintenance Building and a combined sample representing the areas of Buildings No. 1 and No. 2. The attached analytical results show that these areas currently contain the highest levels of airborne contaminants and analytical results from these areas in one year Avill be indicative of any changes. Based on the analytical results from these samples, the need for the above proposed maintenance actions will be reviewed along with the need for any fiirther sampling in the future.

Titan Wheel submits these proposals on the basis that approval by the EPA will allow plant operations to resume within the buildings. The proposed modifications to the Operation and Maintenance Plan will be accomphshed after approval by the EPA.

If you have any questions concerning these matters please contact me at (217) 221-4461.

Sincerely,

/James P. Fechter Corporate Environmental Engineer

cc Cheri Holley Mike Samide Jerry Shanholtzer File

ATTACHMENT A

JAN-03-1995 13:13 FROM 0'ERIEN a GERE MI. TO 121722898718259 P.02

Table. lJ/4/94Buading 1 air sampling results

Sample number

B1-15-P

B1-16-XF

Volume (mO

456.0

4515

Compound

Aidrin

Dieldtui

H^tachlor

ChlortLuuft

2^,7,8-TCDD

2,4-D

2.4^-T

Sampling & en;ilytical method

T 0 4

TCM

TO-4

TO-4

TO-9

Modified SWg46 (8150 mediod)

Anafytical result (mg/m*)

4.2E-S

1.6E-6

<WE-6 (R)

7.2E.7 (J)

5.0E-13

<5JE-5

<1.1E-5

Action levdl (mg/m»)

l E ^

lE-0<5

3E-06

1E^5

lE-10

5E-03

5E^3

R - Raised repotting limit diie to high analyte lc»el»-J - ResTib is detected below the reporting limit or is an estzmated concentration.

DRAFT

J(^J-03-19g5 13:13 FROM O'BRIEN 8. GERE MI. TO 121722998718259 P.03

TaHe. 1 2 / 4 / ^ Bink&ng 2 air sampling resuhii

Sample Volume Compound Sampling <& Analyu'cal nmnber (m'} analytical rosull

mcdiod (mg/m')

Action level (mg/m')

B2-14-P

B2'13-PX

451.4

452^

Aldrin

Dieldrin

Ueptachloc

Oilordaae

2.3.7,8'TCDD

2,4-D

2,4^-T

TCM

TCM

TO-4

TCM

TT>9

Modified SW846 (8150 method)

L6E-3

l^E-6

l l E - 6 (R)

1.5E.6 (J)

1.9E-13

<5JE-5

<l.lE-5

lE-06

1E.06

3E46

lEr05

lE-10

5E-03

5E.03

R - Raised reporting Hmit due to high ana^e leveb. J - Residit is detected below the reporting Ibnit or is an estimated concentration.

DRAFT

JWJ-03-1995 13:14 FROM O'BRIEN 8. GERE Ml TO 121722698718259 P.04

Table. 12/4/94ttailding3 aif tampEngresultt

San^ile num.ber

Volume Compound Sampling ifr Analytical Action level (m*) analytic*! result (mg/mi*)

method (mg/mQ '

B3-11-P

^A-n-TX

453.0

456.6

Aldrin

Dieldrin

Heptadblor

Chlordane

2,3,7,8-TCDD

2,4-D

2.4,5-T

TCM

TCM

TO-4

T O ^

TD.9

Modified SW846 (8150 method)

6.4E-6

2 ^ - ^

2.9E-6 (R)

2.8E-6

<3.1E-14

<53E-5

<UErS

IH4)6

lE-06

3 E ^

lE-05

lE-JO

5E-03

5E-03

R • Raised r«portiag limit due to high analyte levels.

DRAFT

^'^-:^!:.^?:^ j?;/j» f OM. O'BRIEN ?. GERE MI. TO 121722898718259 P.05

Table . 12/4/94 Building 4/5 air sampling results

SaxDple number

VoIuoMi (m»)

Compound Sait >Ung<S: analytical method

Analytical result (mg/ro^

ActiotLlevftl (mg/m*)

B5-2-P

B6.1.P (B5-2PP

duplicate*)

B44^PX

B6-3.PX (B4-4.PX duplicate")

457.8

45a8

454.4

444.6

• Duplicate san^les •

Aldrin

Dieldrin

Heptadilor

Chlordane

23,7,8-TCDD

Aldrin

Dieldrin

Beptacfalor

Oilordane

2,3.7,g.T(DD

2.4-D

2.4.5-T

2,4-D

2 ,4^T

Pert«nt variation

TCM

TCM

TCM

TO-4

TO-9

TCM

TCM-

TO-4

TCM

TO-9

ModiGed SW846 (8150 method)

Modified SW846 (8150 method)

5.0E-6

lSE-6

4.4E-6 (R)

2 J E ^

< 1.06-14

4.9E^

2.0E-6

4.7E.^ (R)

1 5 B ^

<6.4E-15

<5.5&-5

<l.lE-5

<5.6E-5

<l.l&-5

Aldrin =* 2% Dieldrin « 5% Heptachlor « 7% Chlordane = 9% 2,3,7,8-TCDD - Not appKnaWe 2,4D - Not applicable 2 ,4^T « Not applicable

lE-06

1&06

3E-06

lB-05

lE-10

lE-06

lE-06

3E-P6

l E ^

1E40

5E-Q3

S B m

5E-03

5E-03

R - Raiscad r<yoiting Hmit doe to h i ^ analyte levels.

DRAFT

J(:iN-03-1995 13:14 FROM O'BRIEW & GERE MI. TO 121722998718259 P.06

Table . 12/4/94 MainterWKe Building air sampliag results

Sample ntuuuef

Volume Compound Sampling & anaJyticai method

Analytical result (mg/m')

Action level (mg/m*)

MB.7.P

'l

MB^-P-MS (matrix spike*)

MR5-XP

MB^PX-MS (matrix ^ike*)

* Matrix spilce

440.4

447.5

457.9

4602

AWrfa

Dieldrin

Heptachlor

Chlordane

TCM

TCM

TCM

TCM

2 3 , 7 ^ T r i ) D TO-9

Aldrin

Diddrin

H^tadblor

Chlordane

T Q ^

TO-4

TCM

TO-4

23.7,8-TCDD TO-9

2,4-D

2,4,5-T

2AD

2,4,5-T

- Amount added in lab

Percent recovery

MoHifini SW 846 (8150 method)

Modified SW 846 (8150 method)

2,lB-5

2.lEr6

6.1E-6 (R)

3.6E-6

<L9E-14

0.0031 mg

0.002 mg

0.011 fflg(R)

0.026 mg

6.3E-tO mg

<5.5E-5

<1.1E.5

1E.06

lE-06

3E-06

lE-OS

lE-10

NA

NA

NA

NA

NA

sBrCa

5E-03

NA

NA

Aldrin <• mg Dieldrin = mg Heptachlor » mg Chlordane • mg 2^,7.8-TCnD - mg ^ ^ . _

|i?T=^ DRAFT Aldrin « % Dieldrin = % Hqitachlnr » % Oilordane « % 23.7,8.TCDD = % 2,4-D = % 2,4A-T = %

R - Raised r^>oning limit due lo high a n a ^ e Jkveb. NA • Not applicable

JAN-03-1995 13:15 FPOii O'BRIEN S- GERE Ml TO 121722S98718259 P.07

Table. V2./i/94 Outside air sampling results

Sample number

O-IO-P

0-9-PX

Volume

472.5

466.9

C^ompound

Aldrin

Dieldrin

Heptachlor

Chlordane

2^,7,8-TCDD

2,4-D

2,4,5-T

Sampling & analytical method

IXM

TO-4

TO-4

T O ^

TO.9

Modified SW846 (81S0 method)

Analytical result (mg/m')

7.0E-7

4.7E.7 (J)

<42E-7

<4.2E-7

<UE-14 .

<S.4E-5

<l.lE-5

Action level (mg/mO

l E ^

lE-06

3E-06

lE-05

lE-10

5 E ^

5E-Q3

J - Result is detected below the reporting limit or ia an estimated concentration.

DRAFT

JAN-03-1995 13:15 FROM G'BRIBJ g GERE MI. TO 121722998718259 P.08

Table . 12/A/94 Blank air sampling results

Sample Volume nmnbar (m^

Blank -^

Blank —

NA - Not ^Tplicahle

Compound

Aldrin

Dieldrin

H^tachlor

CSilordane'

2 3 , 7 , 8 . I X : D D

2,4-D

2,4,5.T

Sampling & analytical method

TCM

TCM

TO-4

TO-4

TO.9

Modified SW846 (8150 mediod)

Anftlytica) result (mg)

< 0.0002

<0.0004

< 0.0002

< 0.0002

<ZSE-12

< 0.025

<0.005

Action level (mg/m')

NA

NA

NA

NA

NA

NA

NA

DRAFT

ATTACHMENT B

O'BRIEN & CERE ENGINEERS, INC. MEMORANDUM

t f V l ^ To: SLCormieM^ r ^ l c P ^ * * ' ' G Curtis (USEPA) Fmnv AamerRaza \J%>'* T Tumbull (City Env) Re: DICO Risk Evaluation J Fechter (Titan Wheel) File: Date: August 2, 1994

The purpose of this memo is to discuss the potential human health risks associated with measured indoor air pesticide concentrations at the DICO Inc. facility in Des Moines, Iowa. The indoor air sampling was conducted between July 7 and July 9 1994. The results of the indoor air sampling program were presented in a memo from Myron Parkolap dated July 28 1994. The following items are discussed in this memo :

1) Cumulative Risk Estimates based on Current Data 2) Evaluation of derived Cumulative Risk Levels

Overall, it is our opinion that the detected concentrations of pesticides in indoor air at the DICO facility do not represent a "significant" health risk to workers, as per stated USEPA guidance, as well as considerations of recommended occupational exposure limits for workers. An important consideration in this matter is that the DICO facility is an industrial setting and is highly unlikely to result in the exposure of children, elderly, infirm, or otherwise susceptible individuals.

l i Cumulative Risk Levels

The potential risk associated with inhalation of airborne pesticide residue levels detected at the DICO facility is presented on Table 1. The cumulative lifetime excess cancer risk estimates and hazard index for a worker potentially exposed for 8 hours a day, 260 days per year, for 30 years was calculated according to standard intake equations and current USEPA cancer slope factors and chronic RfDs, from USEPA's Integrated Risk Information System (IRIS) database. For this assessment, it was assumed that a worker would have an average inhalation rate of 1.4 m'/hour, which is consistent with a moderate activity level (climbing stairs, heavy repairs, construction) (USEPA 1989).

The calculated Chronic Daily Intakes (CDIs) and risk calculations are presented on Table 1. As shown on Table 1, the total excess lifetime cancer risk associated with the measured pesticide levels (as per USEPA methodology and toxicologic data) is 1.8 x 10', and the Hazard Index is 0.08. Further discussion regarding the interpretation of this information with respect to human health, as well as regulatory implications is presented below.

21 Evaluation of Derived Risk Levels

The potential acceptability of the air concentrations detected at the DICO facility, and the associated cancer risk levels were interpreted with respect to the following considerations :

O

O'BRIEN & GERE ENGINEERS, INC. MEMORANDUM

Memo to: SL Cormier August 2, 1994 Page 2

DRAf

a) Consistency with Federal Guidance - the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) - Final Rule (40 CFR 300, March 8 1990) states that the "acceptable risk range for Superfund cleanups [is] 10"* to 10"*". According to the NCP, "10"* [is] a point of departure, but may be revised to a different risk level based on consideration of ... exposure factors, uncertainty factors, and technical factors. Technical factors may include ... technical limits to remediation". In other words a risk level below 10"* is a starting target level, but risk levels up to 10"* may be acceptable, depending on site specific circumstances.

Since the calculated risk level of 1.8 x 10' at the DICO facility is less than the 10** level, the detected concentrations may be considered to be acceptable risk levels, particularly when one considers that the site is not a residential site and is expected to remain an industrial site. This is further emphasized in the NCP which states that " [for example] contamiiiated soil at an industrial site might be cleaned to a less stringent standard, but still within the 10"* to 10"* risk range, than soil at a residential site".

b) Comparison with Occupational Exposure Levels - While we recognize that occupational exposure levels are not conventionally utilized by USEPA for regulating community exposure, we thought it would be insightful to present recommended occupational exposure limits for these chemicals derived by the American Conference of Governmental Industrial Hygienists (ACGIH), since the potential exposures at the DICO facility strictly relate to occupational exposures. The Threshold Limit Value - Time Weighted Average (TLV-TWA) for dieldrin, chlordane, aldrin, and heptachlor are 0.25 mg/m'* 0.5 mg/m' , 0.25 mg/m' , and 0.5 mg/m' respectively. As defined by ACGIH, "the TLV-TWA represents the time weighted average concentration for a normal 8-hour workday and a 40 hour workweek, to which nearly all workers may be rcpcatedy exposed, day after day, without adverse effect*. As shown un Table 1, the detected concentrations in indoor air at the DICO facility are approximately 3 to 4 orders of magnitude lower than the TLV-TWA values recommended by ACGIH. Therefore, the detected concentrations at the DICO facility would not be considered significant with respect to potential health risks for workers in an occupational setting.

c) Comparison with other Regulatory Levels - As a general comparison, we compared or calculated Chronic Daily Intakes (GDIs) for the detected pesticides with the equivalent GDIs that may occur for an individual drinking water at the Federal potable water Maximum Contaminant Level (MCLs) for those pesticides. The current MCL for chlordane, is 0.002 mg/1 and the MCL for heptachlor is 0.0004 mg/1. No MCLs are available for aldrin and dieldrin. If one assumes that a 70 kg adult may consume 21 of water per day, the CDI for that individual would be 6 x 10"' mg/kg-day and 1.1 x 10^ mg/kg-day for chlordane and heptachlor respectively. As shown on Table 1, the calculated intakes for chlordane and heptachlor, based

D

O'BRIEN & GERE ENGINEERS, INC. MEMORANDUM

Memo to: SL Cormier August 2, 1994 Page 3

DRAFT

on the applied exposure assumptions, are 1 x 10"* and 7 x 10' respectively, which is over one order of magnitude less than the CDI that would be experienced if the individual had been drinking water at the Federal regulatory limits for these analytes. While we recognize that the MCL3 may be based on considerations other than risk based factors, the comparison illustrates that the exposures experienced by the workers at the DICO facility may within the levels that are considered "acceptable" for community exposures (including children and susceptible receptors) to these pesticides under current Federal drinking water guidelines.

3

INTAKE - (CA*IR*EF*EO)/(BW*AT)

Table 1.

DICO Indoor Air I iCalculations

DRAFT

Aldrin

Dialdrin

HeptachI

Ch Jordan

6.1E-06

1.1E-05

1.5E-05

2.2E-05

1.4

1.4

1.4

1.4

260

260

260

260

30

30

30

30

70

70

70

70

10950

10950

10950

10950

6.95E-07 1.25E-06 1.71E-06 2.S1E-06

25550 25550 25550 25550

2.986-07 5.37E-07 7.33E-07 1.07E-06

Total 1.8E-0S