i

COVER SHEET

Name of Site: West Troy Contaminated Aquifer

EPA ID No.: OHN000508132

Contact Person

United States Environmental Protection Agency (EPA), Region V:

Patrick Hamblin

77 West Jackson Boulevard, Mail Code: SR-6J

Chicago, Illinois 60604

(312) 886-6312

Site Investigation: Jon R. Watterworth

Ohio Environmental Protection Agency

Division of Emergency and Remedial Response

401 East Fifth Street

Dayton, Ohio 45402-2911

(937) 285-6062 (direct)

Pathways, Components or Threat Not Scored

The surface water migration, soil exposure, and air migration pathways are not scored as part of this 

Hazard Ranking System (HRS) evaluation. The surface water migration, soil exposure, and air migration 

pathways were not included because a release to these media does not significantly affect the listing 

decision, as based on the ground water pathway, the site scores well above 28.50. 
1

HRS DOCUMENTATION RECORD

Name of Site: West Troy Contaminated Aquifer

Date Prepared: March 2012, Revised September 2012

EPA Region: V

Street Address*: Adams Street and CR 25A

City, County, State, Zip Code: Troy, Miami, Ohio, 45373 (Figure 1) (Ref. 3, p. 1)

General Location in State: West-central portion of Ohio in the City of Troy along the eastern and 

western banks of the Great Miami River (Ref. 3, p. 1)

Topographic Map: U.S. Geological Survey 7.5-Minute Series Topographic Map of Troy, 

Ohio, Quadrangle, 1961, Photorevised 1982, Photoinspected 1984 (Ref. 

3, p. 1)

Latitude*: 40○ 2’ 47.07” North (Ref. 3, p. 1; Ref. 4, p. 1)

Longitude*: 84○ 12’ 32.14” West (Ref. 3, p. 1; Ref. 4, p. 1)

The latitude and longitude listed above mark the approximate location of the West Troy Contaminated 

Aquifer, specifically approximate location of public supply well PW-12W (Ref. 4, pp. 1, 2).

*The street address, coordinates, and contaminant locations presented in this HRS documentation record 

identify the general area where the site is located. They represent one or more locations EPA considers to 

be part of the site based on the screening information EPA used to evaluate the site for NPL listing. EPA 

lists national priorities among the known “releases or threatened releases” of hazardous substances; thus, 

the focus is on the release, not precisely delineated boundaries. A site is defined as where a hazardous 

substance has been “deposited, stored, placed, or otherwise come to be located.” Generally, HRS scoring 

and the subsequent listing of a release merely represent the initial determination that a certain area may 

need to be addressed under the Comprehensive Environmental Response, Compensation, and Liability 

Act (CERCLA). Accordingly, EPA contemplates that the preliminary description of facility boundaries 

at the time of scoring will be refined as more information is developed regarding where the contamination 

has come to be located.

Scores

Ground Water Migration Pathway - 100.00

Surface Water Migration Pathway - Not Scored

Soil Exposure Pathway - Not Scored

Air Migration Pathway - Not Scored

HRS SITE SCORE 50.00
2

WORKSHEET FOR COMPUTING HRS SITE SCORE

S S2

1. Ground Water Migration Pathway Score (Sgw) 

(from Table 3-1, line 13) 100 10,000

2a. Surface Water Overland/Flood Migration Component 

(from Table 4-1, line 30) NS ---

2b Ground Water to Surface Water Migration Component 

(from Table 4-25, line 28) NS ---

2c. Surface Water Migration Pathway Score (Ssw)

(enter the larger of lines 2a and 2b as the pathway score) NS ---

3. Soil Exposure Pathway Score (Ss)

(from Table 5-1, line 22) NS ---

4. Air Migration Pathway Score (Sa)

(from Table 6-1, line 12) NS ---

5. Total of Sgw

2

 + Ssw 2

+ Ss

2 + Sa2 10,000

6. HRS Site Score 50.00

Divide the value on line 5 by 4 and take the square root.

Note:

NS – Not Scored
3

HRS TABLE 3-1 – GROUND WATER MIGRATION PATHWAY SCORESHEET

WEST TROY CONTAMINATED AQUIFER 

Factor Categories and Factors Maximum Value Value Assigned

Likelihood of Release to an Aquifer:

1. Observed Release 550 550

2. Potential to Release:

 2a. Containment 10 NS

 2b. Net Precipitation 10 NS

 2c. Depth to Aquifer 5 NS

 2d. Travel Time 35 NS

 2e. Potential to Release (lines 2a x (2b+ 2c+2d)) 500 NS

3. Likelihood of Release (higher of lines 1 and 2e) 550 550

Waste Characteristics:

4. Toxicity/Mobility (a) 1000

5. Hazardous Waste Quantity (a) 100

6. Waste Characteristics 100 18

Targets:

7. Nearest Well 50 50

8. Population:

 8a. Level I Concentrations (b) 35,540

 8b. Level II Concentrations (b) 0

 8c. Potential Contamination (b) NS

 8d. Population (lines 8a+8b+8c) (b) 35,540

9. Resources 5 5

10. Wellhead Protection Area 20 0

11. Targets (lines 7+8d+9+10) (b) 35,595

Ground Water Migration Score for an Aquifer

12. Aquifer Score [(lines 3X6X11)/82,500]c 100 100.00

Ground Water Migration Pathway Score:

13. Pathway Score (Sgw) (highest value from line 12 for 

all aquifers evaluated) c

100 100.00

Notes:

a. Maximum value applies to waste characteristics category

b. Maximum value not applicable

c. Do not round to nearest integer

NS - Not Scored
Figure 1

Site Location Map

750 E. Bunker Ct.

Vernon Hills, Illinois 60061

WESTON

SOLUTIONS, INC

Prepared By:

TDD: S05-0008-1102-012

Prepared for:

DCN: 1381-2A-AMCN

Contract No:

Troy, Miami County, Ohio

West Troy Contaminated Aquifer EP-S5-06-04

U.S. EPA. REGION V

J:\CAD93\000\02707.dwg, 2/3/2012 11:14:58 AM
Figure 2

ESI Sampling Locations

750 E. Bunker Ct.

Vernon Hills, Illinois 60061

WESTON

SOLUTIONS, INC

Prepared By:

TDD: S05-0008-1102-012

Prepared for:

DCN: 1381-2A-AMCN

Contract No:

Troy, Miami County, Ohio

West Troy Contaminated Aquifer EP-S5-06-04

U.S. EPA. REGION V

J:\CAD93\000\02707.dwg, 2/3/2012 11:09:05 AM
Figure 3

Monitoring Well Location Map

750 E. Bunker Ct.

Vernon Hills, Illinois 60061

WESTON

SOLUTIONS, INC

Prepared By:

TDD: S05-0008-1102-012

Prepared for:

DCN: 1381-2A-AMCN

Contract No:

Troy, Miami County, Ohio

West Troy Contaminated Aquifer EP-S5-06-04

U.S. EPA. REGION V

J:\CAD93\000\02707.dwg, 2/3/2012 11:08:41 AM
7

REFERENCES

1. U.S. Environmental Protection Agency (EPA). Hazard Ranking System, Final Rule, Title 40 Code of 

Federal Regulations (CFR), Part 300, 55 Federal Register (FR) 51532. December 14, 1990. 138

pages. http://www.epa.gov/superfund/sites/npl/hrsres/index.htm#HRS Rule

Note: A complete copy of the Hazard Ranking System, Final Rule, can be obtained at the Regional 

docket upon request.

2. EPA. Superfund Chemical Data Matrix (SCDM), SCDM Data Versions: Jan. 28, 2004, October 23, 

2006, December 2, 2011 and March 31, 2012. Excerpt. 9 pages. A complete copy of SCDM is 

available at: http://www.epa.gov/superfund/sites/npl/hrsres/tools/scdm.htm. 

3. U.S. Geological Survey (USGS). 1982. 7.5-Minute Series Topographic Map: Troy, Ohio, Scale 

1:24,000. Reproduced 05/03/2007. 1 page.

4. Weston Solutions Inc. (WESTON). Longitude and Latitude Calculations for West Troy 

Contaminated Aquifer Site by Brian Coninx, December 6, 2011. 2 pages.

5. Ohio Environmental Protection Agency (Ohio EPA). Combined Preliminary Assessment/Site 

Investigation Report, West Troy Contaminated Aquifer, Troy, Miami County, Ohio. September 21, 

2001. 23 pages.

6. Ohio EPA. Expanded Site Inspection, West Troy Contaminated Aquifer, Troy, Miami County, Ohio. 

September 27, 2005. 51 pages.

7. EPA. National Primary Drinking Water Regulations. 6 pages.

8. Ohio EPA. 2011. Supplemental Expanded Site Inspection Report, West Troy Contaminated Aquifer, 

Troy, Miami County, Ohio. October 27, 2011. 19 pages.

8a. Earth Tech Inc., Troy Ohio Wellfield Investigation Summary Report and Data Package, December 

 30, 1997. 102 pages

9. Ohio EPA. 2011. Draft Supplemental Expanded Site Investigation Report, Appendices, West Troy 

Contaminated Aquifer, Troy, Miami County, Ohio. February 28, 2011. 1950 pages.

9a. Ohio EPA, Interoffice Memo, SESI Pump Test Results Review, West Troy Contaminated Aquifer, 

 November 30, 2010. 43 pages.

9b. Ohio EPA, SESI Pump Test Data, West Troy Contaminated Aquifer. June 2010.

9c. Ohio EPA, SESI Pump Test Data, West Troy Contaminated Aquifer. June 2010.

9d. Ohio EPA, SESI Pump Test Data, West Troy Contaminated Aquifer. August - September 2010.

9e. Ohio EPA, Troy Well Study, Combined Uncorrected Water Depths, West Troy Contaminated 

 Aquifer. August - September 2010.
8

10. EPA. SOM01.2 Volatile Target Compound List and Corresponding CRQLs. Accessed on June 29, 

2010. 2 pages. On-line Address: http://www.epa.gov/oerrpage/superfund/programs/clp/somvtarget.htm 

11. Panterra Corporation. Wellhead Protection Area Delineation and Potential Contaminant Source 

Inventory. Volume 1. August 24, 1994. 155 pages.

12. WESTON. E-mail Message to Omprakash Patel, WESTON, Regarding Troy Text Data Files for 

Discharge Measurements Downstream of Troy Low Dam. March 29, 2011, 42 pages.

13. University of Idaho. Perchloroethylene (PCE) in Dry Cleaning Establishments. December 2000. 17 

pages.

14. City of Troy, Troy Water System Information. 1 page

15. Malcolm Pirnie. Source Water Assessment and Protection Program Update. August 2010. 8 pages.

16. State of Ohio. Water Withdrawal Facility Registration Annual Report Form, City of Troy, Ohio. 7 

January 2011. 2 pages.

17. WESTON. Record of Telephone Conversation Record between Lauren Pesce, WESTON, and Tim 

Ray, Water Plant Superintendent, Troy Water Department, City of Troy, Ohio. March 9, 2011. 4

pages.

17a. WESTON. Record of Telephone Conversation, between Omprakash Patel, WESTON, and Tim Ray, 

 Water Plant Superintendent, Troy Water Department, City of Troy, Ohio. November 22, 2011. 

 1 page.

18. U. S. Census Bureau. Miami County, Ohio, 2005-2009 American Community Survey 5-Year 

Estimates. 2 pages.

19. WESTON. Record of Telephone Conversation, between Lauren Pesce, WESTON, and Don Knife, 

Lead Operator, West Milton Village Water Department, West Milton, Ohio. March 23, 2011. 1

page.

20. Australian Government, Department of Sustainability, Environment, Water, Population and 

Communities. Fact Sheet, Tetrachloroethylene. 3 pages. On-line Address: 

http://www.environment.gov.au/atmosphere/airquality/publications/sok/tetrachloroethylene.h

tml Accessed on July 29, 2011.

21. State of Wisconsin, Wisconsin Department of Health and Family Services, Information on Toxic 

Chemicals, Trichloroethylene. December 2000. 2 pages.

22. Eco-usa.net. 1,1,1-Trichloroethane. 2 pages. On-line Address: 

http://www.eco-usa.net/toxics/chemicals/1,1,1-trichloroethane.shtml 

23. Department of Health, New York State, Bureau of Toxic Substance Assessment. Tenant Notification 

Fact Sheet for 1,2-Dichloroethene. February 2011. 2 pages.

24. WESTON. Record of Telephone Conversation between Lauren Pesce, WESTON, and Jeff Shields, 

Superintendent, Miami County Public Water System, Troy, Ohio. March 23, 2011. 1 page.
9

25. WESTON. Record of Telephone Conversation Record between Lauren Pesce, WESTON, and Tim 

Ray, Water Plant Superintendent, Troy Water Department, City of Troy, Ohio. March 23, 2011. 1 

page.

26. WESTON. Calculations for City of Troy Municipal Pumpage Percentage by Omprakash Patel. 

December 14, 2011. 1 page. 

27. Miami County Sanitary Engineering Department. 2009 Drinking Water Quality Report. 3 pages.

28. USGS. 4-Mile Radius Target Distance Map. 7.5-Minute Series Topographic Maps with a Scale of 

1:24,000 for the Following: Troy, Ohio, 1982; New Carlisle, Ohio, 1973; Christianburg, Ohio, 1992;

Pleasant Hill, Ohio, 1961; West Milton, Ohio, Reproduced on May 3, 2007. 1 Page.
10

1.0 SITE DESCRIPTION

The City of Troy is located in Miami County, Ohio, approximately 20 miles north of the City of Dayton 

(Ref. 5, p. 5). The City of Troy operates two well fields located along a 1.25-mile-long segment of the 

Great Miami River in Miami County, Ohio (Refs. 5, p. 5; 6, p. 5). Five wells are located in the West Well 

Field, and five wells are located in the East Well Field (Refs. 17; 17a). The West Well Field is located on 

the east bank of the Great Miami River north of the downtown business district (Ref. 5, p. 5). The wells 

are screened in sand and gravel, and individual wells produce as much as 1,500 gallons per minute (gpm) 

(Refs. 5, p. 5; 6, p. 5). Since 1986, volatile organic compounds (VOC) have been detected in well 12W in 

the west well field (Ref. 5. p. 5; Ref. 6, p. 6). Specifically, tetrachloroethene (PCE) has been detected in 

public well PW-12W in the West Well Field at concentrations as high as 7.27 micrograms per liter (μg/L) 

and in finished water at the water treatment plant at concentrations as high as 1.56 μg/L (Refs, 5, p. 5; 6, 

p. 6). The federal drinking water maximum contaminant level (MCL) for PCE is 5 μg/L (Refs. 5, p. 6; 6,

p. 6; 7, p. 3).

The West Troy Contaminated Aquifer is a ground water plume of chlorinated solvents in the west well 

field in the City of Troy, Miami County, Ohio (Figure 1). The site has been characterized as a ground 

water plume with no identified source. The plume has been shown to include volatile organic compounds 

(VOCs) at levels above background in at least one public drinking water supply well in the City of Troy’s 

west well field. Tetrachloroethene (PCE) is the primary chlorinated solvent detected in the city well and 

other wells defining the plume (Refs. 6, p. 11; 8, pp. 13, 14). Trichloroethene (TCE) and cis-1,2-

dichloroethene (DCE) also have been detected in drinking water and monitoring wells (Ref. 6, pp. 10, 

11). The site scoring is based on a Level I concentration of PCE detected in city well PW-12W. A 

National Priorities List site with a chlorinated solvent ground water plume is located south of the West 

Troy Contaminated Aquifer. 

The location of the ground water plume was approximated based on results for ground water samples 

collected from public wells, monitoring wells, and direct-push sampling devices (Figure 1). The precise 

extent of the ground water plume and possible source(s) of ground water contamination have not yet been 

identified. The rough outline of the plume extends from the location of the former Wampler Buick/GMC 

property at 507 and 515 N. Elm Street in Troy in a southeasterly direction across (under) the Great Miami 

River and then to the City of Troy’s west well field on the east side of the river (Figure 1).
11

Since ground water contamination was first detected in a city well in 1986, numerous investigations have 

been conducted to determine the source and extent of the contamination. Several facilities and properties 

were identified as possible sources in investigations beginning in 1991 and continuing through 2010

(Refs. 5, pp. 5, 6; 6, p. 6; 7, p. 3). These investigations found properties, including the former Wampler 

Buick/GMC facility and the Hobart-Lytle Road landfill, were associated with VOC contamination (Ref. 

5, p. 6). PCE and TCE were detected in soil samples taken from the landfill, but these contaminants were 

not detected in ground water sampling at the facility (Ref. 5, pp. 6, 7). Ground water sampling at the 

former Wampler Buick/GMC property in 1997, during a preliminary assessment/site inspection (PA/SI) 

conducted by Ohio Environmental Protection Agency (Ohio EPA) in 2001, an expanded site inspection 

(ESI) in 2005 and a supplemental ESI in 2010 all detected PCE in ground water (Refs. 5, pp. 6, 8; 6, p.10; 

8, p. 17).

Soil samples collected in 1999 by ITW-Hobart at the Hobart-Lytle Road landfill, located about 4,600 feet 

northwest of the West Troy Contaminated Aquifer, were found to be contaminated with solvents, 

including TCE. Soil samples collected at the landfill in 2000 had detections of PCE and TCE (Ref. 5, pp. 

6, 7). Ground water samples taken by Ohio EPA in 2001 from a property south and east of the landfill 

showed contamination with benzene, ethyl benzene and xylene, but not PCE, TCE or cis-1,2-DCE (Ref. 

5, p. 7). PCE was detected in one monitoring well at another location that was considered a possible 

source, the Hobart Lagoon, located about 600 feet southeast of the Wampler Buick/GMC property, and 

about 100 feet to the west of the Great Miami River. This well was located between the Wampler 

Buick/GMC property and Hobart Lagoon and the concentration of PCE was less than at the Wampler 

Buick/GMC property (Ref. 6, p.6). Therefore, it was concluded that PCE was not released from the 

Hobart Lagoon (Ref. 6, p. 6). 

The supplemental ESI conducted by Ohio EPA in 2010 confirmed contamination of wells PW-12W and 

PW-3W in the City of Troy’s west well field (Refs. 8, p. 14; 9, p. 1941). The supplemental ESI also 

included a pump test of city wells in the west well field; based on the results of the test, Ohio EPA 

concluded that there is a hydraulic connection between the shallow sands and gravels on the west side of 

the Great Miami River (where possible contaminant sources are located and where VOC contamination 

has been detected) and the deeper sands and gravels on the east side of the river from which the city wells 

draw (Ref. 8, p. 15).

In 2010, monitoring wells at the former Wampler Buick/GMC property again showed contamination with 

VOCs, including PCE (Refs. 8, p. 14; 9, pp. 1941, 1942). Based on this and previous investigations, Ohio 

EPA concluded that Wampler Buick/GMC, and other possible sources investigated, could not be 
12

confirmed as at least contributing to the observed VOC contamination in the ground water plume 

impacting public drinking water well PW-12W, and the source was characterized as a ground water 

plume with no identified source.

A ground water sample collected south of Morgan’s Ditch in 1997 contained PCE, and this finding may 

indicate a source located west of the Wampler Buick/GMC properties (Refs. 8, pp. 8, 16; 8A, p. 25). The 

Troy Filler Metals Operation at 101 Trade Square East is located west of the Wampler Buick/GMC 

properties and PW-12W and has a history of solvent use, including use of chlorinated compounds (Ref. 8, 

p. 17). An additional 5 facilities potentially upgradient of the site that have potentially used solvents were 

also identified. These facilities are described in detail in the “Description of Other Possible Sources”

section of this HRS documentation record. The identified facilities are summarized below:

1. The Re-store: The Re-store is located at 500 North Elm Street, in Troy, Ohio (Ref. 9, p. 87). 

2. Webster’s Auto: Webster’s Auto repair is located at 525 North Elm Street, Troy, Ohio (Ref. 

9, p. 90). 

3. Miami County Garage: Miami County Garage is located at 670 Harrison Street, Troy, Ohio 

(Ref. 9, p. 90). 

4. Former Trojan Specialties: Former Trojan Specialties is located at 745 Harrison Street, Troy, 

Ohio (Ref. 9, p. 91). A vacant commercial building is present at this location (Ref. 9, p. 91). 

Previously, Trojan Specialties was present at this location (Ref. 9, p. 91)

5. Action Tire Auto Center: Action Tire and Auto Center is located at 816 Harrison Street, 

Troy, Ohio (Ref. 9, p. 91). 

1.1 INVESTIGATIONS PERFORMED AT THE SITE

In 1991, the Ohio EPA began searching for a source of the VOC contamination (Ref. 5, p. 6). In 1997, 

the Ohio EPA collected direct-push technology ground water samples in and around the Wampler 

Buick/GMC location (Ref. 5, p. 6). 

In 1999, ITW-Hobart collected soil samples from the Hobart-Lytle Road landfill, and results indicated 

that solvents, including trichloroethene (TCE), were present in soil (Ref. 5, p. 6).

In 2001, the Ohio EPA conducted a combined preliminary assessment/site investigation (PA/SI) and 

advanced four direct-push borings to approximately 10 to 12 feet below ground surface (bgs) at an 
13

agricultural field south of the Earhart Petroleum facility and east of the Hobart-Lytle Road landfill (Ref. 

5, p. 6). The borings were advanced to determine if any VOCs were migrating to the east and south (Ref. 

5, p. 7). Soil samples were collected from the southernmost direct-push borehole for visual and 

laboratory analysis (Ref. 5, p. 6). A soil sample from 8 to 9 feet bgs also was collected and sent to a 

Contract Laboratory Program (CLP) laboratory for analysis for Target Compound List (TCL) VOCs (Ref. 

5, p. 6). Ground water samples were collected from 4 monitoring wells at the Earhart Petroleum property,

4 monitoring wells at the Hobart Lagoon, 6 city monitoring wells, and 11 monitoring wells at the 

Wampler Buick/GMC facility (Ref. 5, p. 6). Troy production wells PW-4W and PW-12W also were 

sampled (Ref. 5, p. 7). Because the screened interval of the city monitoring wells varied from 46 to 140 

feet bgs, multiple samples were collected from each well at different depths (Ref. 5, pp. 6, 7). The water 

samples from the Earhart Petroleum property, the city wells, and the Hobart Lagoon were sent to a CLP 

laboratory for analysis for TCL VOCs (Ref. 5, p. 6). The samples from the Wampler Buick/GMC facility

were sent to a mobile laboratory at the Miamisburg Contaminated Aquifer expanded site investigation 

(ESI) location for VOC analysis using U.S. Environmental Protection Agency (EPA) Method 8260 (Ref. 

5, p. 7). PCE and other VOCs were detected in several wells sampled at the Wampler Buick/GMC facility

(Ref. 5, pp. 7, 8). PCE also was detected in City of Troy production well 12W (Ref. 5, p. 8). 

In 2005, the Ohio EPA completed an ESI at the West Troy Contaminated Aquifer. The ESI focused on 

the two properties at 507 and 515 N. Elm Street located on the east side of N. Elm Street just north of the 

City of Troy corporation limits (Ref. 6, p. 5). Ohio EPA’s contractor, Tetra Tech EM, Inc. (Tetra Tech), 

advanced 11 direct-push borings at the properties to approximately 44 feet bgs (Ref. 6, p. 8). Continuous 

soil samples were collected from borings GP86, GP87, and GP-90 using a core barrel sleeved with a 

plastic liner (Ref. 6, p. 8). The soil samples were screened using a photoionization detector, but no

samples were submitted for laboratory analysis because the VOC field screening results did not exceed 

the screening criteria (Ref. 6, p. 8). Three water samples were collected from 10 of the 11 borings at the 

following approximate depths: 20 to 24, 32 to 36, and 40 to 44 feet bgs (Ref. 6, p. 8). Two water samples 

also were collected from GP-86B at 32 to 36 and 40 to 44 feet bgs (Ref. 6, p. 8). The samples were 

submitted to Severn Trent Laboratories for VOC analysis using EPA SW-846 Method 8260B (Ref. 6, p. 

8). The samples with the highest concentrations of PCE were found in borings GP-84 (41 μg/L) at 20 to 

24 feet bgs and GP-86B (32 μg/L) at 32 to 36 feet bgs (Ref. 6, p. 8).

In 2005, as part of the ESI, Tetra Tech installed five monitoring wells (OEPA-14, OEPA-15, OEPA-16, 

OEPA-17, and OEPA-18) at 507 and 515 N. Elm Street (Ref. 6, p. 10). The well locations and the 

screened intervals were based on the direct-push sampling results, with the goal of verifying the previous 

detections of PCE and establishing background concentrations (Ref. 6, p. 10). On June 13 and 14, 2005, 
14

the five new monitoring wells, two upgradient monitoring wells owned by the City of Troy, two existing 

monitoring wells at 515 N. Elm Street, and city production wells 4W and 12W were sampled (Ref. 6, p. 

10). The monitoring wells were sampled with a peristaltic pump using the micropurging technique (Ref. 

6, p. 10). The two production wells were sampled at the pump houses using ports installed by the city for 

monitoring purposes (Ref. 6, p. 10). A4 Scientific Laboratory analyzed the samples for VOCs using CLP 

Scope of Work (SOW) OLC03.2 methods (Ref. 6, pp. 21, 22). The highest concentration of PCE was 

found in monitoring well OEPA-17 at 21 μg/L (Ref. 6, p. 10). PCE was found in city well 12W at 5.7 

μg/L (Ref. 6, p. 10). 

As part of the PA/SI, the Ohio EPA also evaluated other facilities that may be responsible for the release 

of PCE to ground water, including a Hobart Brothers Corporation complex located 1,800 feet west of the 

West Troy Contaminated Aquifer; the Hobart-Lytle Road landfill located 4,600 feet northwest of the 

West Troy Contaminated Aquifer; and several small commercial facilities located on County Road 25A 

north of the Site (Ref. 6, p. 6). No evidence regarding the disposal of PCE was obtained from any 

neighboring facilities (Ref. 6, p. 6). 

In 2010, the Ohio EPA conducted a supplemental ESI of the West Troy Contaminated Aquifer (Ref. 8, p.

1). 

During Phase I of the supplemental ESI, five public wells in the West Well Field were sampled before 

and after the pump test (Ref. 8, p. 5). Production well samples were analyzed for VOCs through the EPA 

CLP (Ref. 8, p. 5). During Phase 2 of the supplemental ESI, 5 West Well Field production wells, 24 

monitoring wells, and 5 private production wells were sampled (Ref. 8, p. 6). KAP Technologies Inc. and 

A4 Scientific Inc. analyzed the ground water samples for VOCs using the CLP SOW SOM01.2 (Ref. 9, 

pp. 1311, 1420, 1505, 1663, and 1821). Ohio EPA Division of Drinking and Ground Waters (DDAGW) 

staff evaluated pump test results and concluded that hydraulic communication exists between the shallow 

sands and gravels on the west side of the Great Miami River and the deeper sands and gravels on the east 

side of the river where PW-12W is located (Ref. 8, p. 6). 

2.2 SOURCE CHARACTERIZATION

2.2.1 Source Identification

Source Number: 1

Source Type: Other – Ground water plume with no identified source

Description and Location of Source (with reference to a map of the site):
15

Source 1 is a contaminated ground water plume containing primarily PCE, with no identified source. 

Other chlorinated solvents detected in ground water include TCE and cis-1,2-DCE. In accordance with 

the Hazard Ranking System (HRS), the plume itself is considered the source (Ref. 1, Sec. 1.1, p. 51587). 

As currently delineated, the Source 1 ground water plume extends from the properties at 507 and 515 N. 

Elm Street west of the City of Troy municipal West Well Field or west of these properties to the vicinity 

of Troy well 12W (Refs. 6, p. 12; 8, p. 16) (Figures 1, and 3). Despite all the investigations performed to 

date, the ground water contamination cannot be attributed to any source with confidence (Ref. 8, p. 6). 

The extent of this plume has not yet been completely delineated but the plume has been characterized 

based on data from residential wells, monitoring wells, and public supply wells (Figure 3) gathered during 

previous investigations.

In April, May, and August 2001, the Ohio EPA conducted a combined PA/SI at the West Troy 

Contaminated Aquifer (Ref. 5, pp. 4, 5). The Ohio EPA advanced four direct-push borings to 

approximately 10 to 12 feet bgs. Ground water samples were collected from 4 monitoring wells at the

Earhart Petroleum property, 4 monitoring wells at the Hobart Lagoon, 6 city monitoring wells, and 11 

monitoring wells at the Wampler Buick/GMC location (Ref. 5, p. 6). Troy production wells 4W and 12W 

also were sampled (Ref. 5, p. 7). The water samples from the Earhart Petroleum property, city wells, and 

the Hobart Lagoon were sent to a CLP laboratory for analysis for TCL VOCs (Ref. 5, p. 7). The samples 

from the Wampler Buick/GMC facility were sent to a mobile laboratory for VOC analysis using EPA 

Method 8260 (Ref. 5, p. 7). PCE and other VOCs were detected in several wells sampled at the Wampler 

Buick/GMC facility (Ref. 5, pp. 7, 8). PCE also was detected in City of Troy production well 12W (Ref. 

5, p. 8). 

In May and June 2005, the Ohio EPA conducted an ESI at the West Troy Contaminated Aquifer (Ref. 6, 

p. 5). Ohio EPA’s contractor, Tetra Tech, advanced 11 direct-push borings at the properties on 507 N. 

Elm Street and 517 N. Elm Street to approximately 44 feet bgs (Ref. 6, pp. 5, 8). Continuous soil samples 

were collected from borings GP86, GP87, and GP-90 using a core barrel sleeved with a plastic liner (Ref. 

6, p. 8). The soil samples were screened using a photoionization detector, but no samples were submitted 

for laboratory analysis because the VOC field screening results did not exceed the screening criteria (Ref. 

6, p. 8). Three water samples were collected from 10 of the 11 borings at the following approximate 

depths: 20 to 24, 32 to 36, and 40 to 44 feet bgs (Ref. 6, p. 8). Two water samples also were collected 

from GP-86B at 32 to 36 and 40 to 44 feet bgs (Ref. 6, p. 8). The samples with the highest concentrations 

of PCE were found in borings GP-84 (41 μg/L) at 20 to 24 feet bgs and GP-86B (32 μg/L) at 32 to 36 feet 

bgs (Ref. 6, p. 8). 
16

During Phase I of the supplemental ESI, five public wells in the West Well Field were sampled before 

and after the pump test (Ref. 8, p. 5). Production well samples were analyzed for VOCs through the EPA 

CLP (Ref. 8, p. 5). During Phase 2 of the supplemental ESI, 5 West Well Field production wells, 24 

monitoring wells, and 5 private production wells were sampled (Ref. 8, p. 6). KAP Technologies Inc. and 

A4 Scientific Inc. analyzed the ground water samples for VOCs using the CLP SOW SOM01.2 (Ref. 9, 

pp. 1311, 1420, 1505, 1663, 1821). Ground water sampling results confirmed that West Well Field wells 

PW-12W and PW-3W are contaminated with VOCs (Ref. 8, p. 16). PCE was detected at concentrations 

exceeding its MCL in PW-12W. TCE, DCE, and TCA were detected in PW-12W at concentrations 

below their respective MCLs (Ref. 8, p. 17). DCE was detected in PW-3W for the first time in 

supplemental ESI samples, but all detections were below the DCE MCL (Ref. 8, p. 17). TCA was 

detected in samples from two private production wells (non-potable) on the west side of the Great Miami 

River (Ref. 8, p. 17). The City of Troy minimized pumping PW-12W and blended water from both well 

fields to reduce VOC concentrations to below detectable limits in finished water (Ref. 8, p. 17). 

2.2.2 Hazardous Substances Associated with the Source

The following ground water data are presented to illustrate the hazardous substances associated with 

Source 1. During the Phase I of the supplemental ESI, five public wells in the West Well Field were 

sampled before and after the pump test (Ref. 8, p. 5). Production well samples were analyzed for VOCs 

through the EPA CLP (Ref. 8, p. 5). During Phase 2 of the supplemental ESI, 5 West Well Field 

production wells, 24 monitoring wells, and 5 private production wells were sampled (Ref. 8, p. 6). KAP 

Technologies Inc. and A4 Scientific Inc. analyzed the ground water samples for VOCs using the CLP 

SOW SOM01.2 (Ref. 9, pp. 1311, 1420, 1505, 1663, 1821). The hazardous substance associated with 

Source 1 is primarily PCE. However, TCE and cis-1,2-DCE also have been detected in the 

unconsolidated aquifer (Ref. 8, pp. 7, 8). Figure 1 shows the location of Source 1.

Background Levels:

- Background Level at Source 1 – Other -- Contaminant Plume

Regional ground water flow is south following the Great Miami River valley (Ref. 8, p. 16). Ground 

water at Troy is part of the Great Miami River Buried Valley Aquifer System (Refs. 8, p. 16; 9, pp. 

128,129). Based on available ground water flow information, monitoring wells MW-C, MW-E and MWK are considered to be background (upgradient) wells. Figure 3 shows the background sampling

locations. The contaminants of concern for the West Troy Contaminated Aquifer (PCE; TCE; and cis1,2-DCE) were not detected in ground water samples collected from the background monitoring well 
17

locations (Ref. 9, pp. 1602, 1603, 1722, 1723, 1725, 1726, 1728, 1729, 1731, 1732, 1734, 1735, 1737, 

1738, 1861, 1862). The absence of contaminants of concern in the ground water samples suggests that 

the background locations to the depth of approximately 140 feet bgs lie outside the area of contamination. 

Table 1 below summarizes background location information and the concentrations of contaminants of 

concern for the site detected in ground water samples collected from each location. 

TABLE 1

BACKGROUND LOCATION AND CONCENTRATION INFORMATION

Location 

No. Aquifer

Well or 

Sampling

Depth

(feet bgs)

Well

Screen 

Interval or 

Screen 

Length

(feet)

Sample 

No.

Sampling 

Date

Hazardous 

Substance

Concentration 

Detected (μg/L)

CRQL

(μg/L) References

MW-E_S UC 25 15-125 E2509 7/19/2010 PCE 0.5 U 0.5 Refs. 6, p. 50; 9, 

pp. 1001,1554, 

1662-

1669,1674, 

1675, 1727-

1729, 1787,

1930, 1949; 10, 

pp. 1, 2

TCE 0.5 U 0.5

cis-1,2-DCE 0.5 U 0.5

MW-E_I UC 70 15-125 E2508 7/19/2010 PCE 0.5 U 0.5 Refs. 6, p. 50; 

9, pp. 1001, 

1554, 1662-

1669,1674, 

1675, 1730-

1732, 1787,

1929,1949; 10, 

pp. 1, 2

TCE 0.5 U 0.5

cis-1,2-DCE 0.5 U 0.5

MW-E_D UC 122 15-125 E2507 7/19/2010 PCE 0.5 U 0.5 Refs. 6, p. 50; 

9, pp. 1001, 

1504 -

1512,1517, 

1518, 1554 

1602-1605, 

1787, 1931; 10, 

pp. 1, 2

TCE 0.5 U 0.5

cis-1,2-DCE 0.5 U 0.5

MW-K_S UC 35 140 E2512 7/19/2010 PCE 0.5 U 0.5 Refs. 9, pp. 

898, 1554, 1787, 

1820-1825, 

1826, 1827, 

1844, 1861-

1863, 1917, 

1949; 10, pp. 

1,2

TCE 0.5 U 0.5

cis-1,2-DCE 0.5 U 0.5

MW-K_I UC 75 140 E2511 7/19/2010 PCE 0.5 U 0.5 Refs. 9, pp. 898, 

1554, 1662 -

1669,1676, 

TCE 0.5 U 0.5

cis-1,2-DCE 0.5 U 0.5
18

Location 

No. Aquifer

Well or 

Sampling

Depth

(feet bgs)

Well

Screen 

Interval or 

Screen 

Length

(feet)

Sample 

No.

Sampling 

Date

Hazardous 

Substance

Concentration 

Detected (μg/L)

CRQL

(μg/L) References

1677, 1721-

1723, 1787, 

1916, 1949; 10, 

pp. 1, 2

MW-K_D UC 121 140 E2510 7/19/2010 PCE 0.5 U 0.5 Refs. 9, pp. 898, 

1662 -

1669,1676, 

1677, 1724-

1726, 1787, 

1926, 1949; 

10, pp. 1,2

TCE 0.5 U 0.5

cis-1,2-DCE 0.5 U 0.5

MW-C_S UC 25 15-61 E2506 7/19/2010 PCE 0.5 U 0.5 Refs. 6, p. 50; 9, 

pp. 1001, 1662-

1669,1674, 

1675, 1733-

1735, 1788, 

1927, 1949; 10, 

pp. 1 2

TCE 0.5 U 0.5

cis-1,2-DCE 0.5 U 0.5

MW-C_D UC 50 15-61 E2505 7/19/2010 PCE 0.5 U 0.5 Refs. 6, p. 50; 

9, pp. 1001, 

1662-

1669,1674, 

1675, 1736-

1738, 1788, 

1928, 1949 ; 

10, pp. 1 2

TCE 0.5 U 0.5

cis-1,2-DCE 0.5 U 0.5

Notes:

μg/L – Microgram per liter 

bgs – Below ground surface

CRQL – Contract-Required Quantitation Limit (Ref. 10, pp. 1 and 2) 

DCE - Dichloroethene

PCE – Tetrachloroethene

TCE - Trichloroethene

U – Analyte was analyzed for but was not detected above the reported sample quantitation limit (Ref. 9, pp. 1512, 

1669, and 1825)

UC – Unconsolidated aquifer

Contaminated Samples:

- Contaminated Samples at Source 1 – Contaminated Plume

Table 2 below summarizes the results for ground water samples contaminated with PCE, TCE and DCE

collected from monitoring wells and public supply wells at the West Troy Contaminated Aquifer. Figure 

3 of this HRS documentation record shows the sampling locations except W-OB.
19

TABLE 2

CONTAMINATED SAMPLE INFORMATION

Location 

No. Aquifer

Well or 

Sampling

Depth

(feet bgs)

Well

Screen 

Interval

(feet)

Sample 

No.

Sampling 

Date

Hazardous 

Substance

Concentration 

Detected (μg/L)

CRQL

(μg/L) References

OEPA-14 UC 44 39-44 E2495 7/21/10 PCE 8.7 0.5 Refs. 6, p. 45; 

9, pp. 1000,

1504-1512, 

1579, 1785,

1905; 10, pp. 1,2

OEPA-16 UC 25 15-25 E2497 7/21/10 10 0.5 Refs. 6, p. 47;9, 

pp. 1000, 1504-

1512, 1585, 

1785,

1907; 10, pp. 1,2

OEPA-17 UC 34 29-34 E2498 7/21/10 18 0.5 Refs. 6, p. 48; 9, 

pp. 1000, 1504-

1512, 1588, 

1785, 1932; 10, 

pp. 1,2

PW-12W UC 86 66-86 E2500 7/21/10 5.20 0.5 Refs. 6, pp.

3839; 9, pp. 

1504-1512, 

1591, 1785,

1911; 10, pp. 1,2

W-3 UC 33.20 NA E2518 7/22/10 7.1 0.5 Refs. 9, pp. 

1504-1512,

1519-1520,

1556, 1923, 

1941; 10, pp. 1,

2

W-8 UC 16.59 7.6-17.5 E2522 7/22/10 3.9 0.5 Refs. 9, pp. 

1001, 1504-

1512, 1557, 

1631, 1921; 10, 

pp. 1,2

W-OB UC 34.45 NA E2521 7/22/10 6.5 0.5 Refs. 9, pp. 

1504-1512, 

1557, 1628, 

1919; 10, pp. 1,

2

RW-5 UC NA NA E2529 7/21/10 9.1 0.5 Refs. 9, pp. 

1820-1825, 

1845, 1875, 

1900; 10, pp. 1,2

PW-12W UC 86 66-86 E2500 7/21/10 TCE 0.81 0.5 Refs. 6, pp.38, 

39; 9, pp. 1504-

1512 ,1591 

1785, 1911; 10, 

pp.1, 2
20

Location 

No. Aquifer

Well or 

Sampling

Depth

(feet bgs)

Well

Screen 

Interval

(feet)

Sample 

No.

Sampling 

Date

Hazardous 

Substance

Concentration 

Detected (μg/L)

CRQL

(μg/L) References

PW-12W UC 86 66-86 E2500 7/21/10 Cis-1,2-

DCE

1.1 0.5 Refs. 6, pp.38, 

39; 9, pp. 1504-

1512, 1590, 

1785, 1911;10, 

pp.1, 2

Notes:

μg/L – Microgram per liter 

bgs – Below ground surface

CRQL – Contract-Required Quantitation Limit (Ref. 10, pp. 1 and 2) 

DCE - Dichloroethene

PCE – Tetrachloroethene

TCE - Trichloroethene

U – Analyte was analyzed for but was not detected above the reported sample quantitation limit (Ref. 9, pp. 1512, 

1669, and 1825)

UC – Unconsolidated aquifer

The background and downgradient monitoring well samples were collected within the same timeframe 

(between July 19 and 22, 2010) (Ref. 9, pp. 1904-1937). The samples were collected with peristaltic

pumps using a low-flow sampling technique (Ref. 9, pp. 1904-1937). The ground water samples were 

collected after the following field parameters had stabilized: pH, conductivity, dissolved oxygen (DO), 

temperature, and oxidation-reduction potential (Ref. 9, pp. 1904-1937). The samples were analyzed by 

the U.S. EPA CLP) for VOCs using same method (Ref. 9, pp. 1504-1512). 

The ground water samples from private and public wells collected on July 21, 2010, are considered in this 

HRS documentation record package (Ref. 9, pp. 1908-1912). The samples were collected on the same 

day by the same sampler (Ref. 9, pp. 1908-1912). The samples were analyzed by the U.S. EPA CLP for 

VOCs (Ref. 9, pp. 1504-1512, 1820-1825).

List of Hazardous Substances Associated with Source: 

The following hazardous substances are associated with the source:

• PCE 

• cis-1,2-DCE 

• TCE
21

2.2.3 Hazardous Substances Available to a Pathway

The soil boring investigations within the plume have shown that there is no liner, maintained engineered 

cover, functioning and maintained run-on control system, runoff management system, or functioning 

leachate collection and removal system (Ref. 6, pp. 42-49). Furthermore, a ground water release of 

hazardous constituents from unknown sources is documented based on analytical results for ground water 

samples collected from the plume. Therefore, the Containment Factor Value (CFV) for the ground water 

migration pathway was assigned a maximum value of 10 (Ref. 1, Section 3.1.2.1, Table 3-2, p. 51596). 

The maximum CFV reflects the minimum level of containment. A source is assigned the maximum CFV 

if there is evidence that hazardous substances have migrated from the source area or that there is no liner, 

maintained engineered cover, functioning leachate collection and removal system, or functioning and 

maintained run-on control system and runoff management system (Ref. 1, Section 3.1.2.1, Table 3-2, p. 

51596). 

The following substances are identified as having been released to the ground water migration pathway: 

PCE; TCE; and cis-1,2-DCE. Table 3 below summarizes the CFVs for each pathway.

TABLE 3

CONTAINMENT FACTOR VALUE SUMMARY

Release Description CFV Reference

Gas Release to Air Not Scored NA

Particulate Release to Air Not Scored NA

Release to Ground Water: Because of evidence of hazardous 

substances migration to ground water, a CFV of 10 was assigned 

(see Sections 2.2.2 and 3.1.1 of this HRS documentation record). 

Soil borings have shown that the source has no liner, maintained 

engineered cover, functioning and maintained run-on control 

system, runoff management system, or functioning leachate 

collection and removal system. A ground water release of 

hazardous constituents from unknown sources is documented 

based on analytical results for ground water samples collected 

from the source

10 Refs. 1, Section 

3.1.2.1, Table 3-2, p. 

51596; 6, pp. 42-49; 

Table 2 of this 

documentation record 

Release through Overland Migration and/or Flood Not Scored NA

Notes:

CFV - Containment Factor Value

HRS - Hazard Ranking System

NA - Not applicable
22

2.4.2 HAZARDOUS WASTE QUANTITY

2.4.2.1 Source Hazardous Waste Quantity

2.4.2.1.1 Hazardous Constituent Quantity (Tier A)

The available information is not sufficient to adequately evaluate Tier A as required in Section 2.4.2.1.1 

of the HRS. As a result, the evaluation of Hazardous Waste Quantity proceeds to the evaluation of Tier 

B, hazardous waste stream quantity (Ref. 1, Section 2.4.2.1.1, pp. 51590-51591).

Hazardous Constituent Quantity Assigned Value: NS

2.4.2.1.2 Hazardous Wastestream Quantity (Tier B)

The available information is not sufficient to adequately evaluate Tier B as required in Section 2.4.2.1.2 

of the HRS. As a result, the evaluation of Hazardous Waste Quantity proceeds to the evaluation of Tier 

C, volume (Ref. 1, Section 2.4.2.1.2, p. 51591).

Hazardous Constituent Quantity Assigned Value: NS

2.4.2.1.3 Volume (Tier C)

Because there is documentation of contamination, but the lateral and vertical extent of the ground water 

plume have not been adequately characterized, the volume for the ground water plume is designated as 

unknown but greater than zero (Tier C) (Ref. 1, Section 2.4.2.1.3, Table 2-5, p. 51591).

Volume Assigned Value: >0

2.4.2.1.4 Area (Tier D)

The area (Tier D) cannot be evaluated (Ref. 1, p. 51591). 

Area Assigned Value: 0

2.4.2.2 Calculation of Source Hazardous Waste Quantity Factor Value

As described in the HRS, the highest value assigned to a source from among the four tiers of hazardous 

constituent quantity (Tier A), hazardous waste stream quantity (Tier B), volume (Tier C), or area (Tier D) 

shall be selected as the source hazardous waste quantity value (Ref. 1, Section 2.4.2.1.5, p. 51591). Table 

4 below summarizes the hazardous waste quantity values.
23

TABLE 4

HAZARDOUS WASTE QUANTITY VALUES

Tier Measure Source Value

Tier A, Hazardous Constituent Quantity NS

Tier B, Hazardous Wastestream Quantity NS

Tier C, Volume >0

Tier D, Area 0

Table 5 below summarizes the source description.

TABLE 5

SOURCE DESCRIPTION SUMMARY

Source 

No.

Source

Hazardous

Waste

Quantity

Value

Source

Hazardous

Constituent

Quantity

Complete?

CFV by Pathway

Ground 

Water Surface Water Air

(Ref. 1, 

Table 3-2)

Overland/

Flood

(Ref. 1, Table 4-2)

Ground Water to 

Surface Water

(Ref. 1, Table 3-2)

Gas

(Ref. 1, 

Table 6-3)

Particulate

(Table 6-9)

1 Unknown, 

but >0 No 10 Not scored Not scored Not scored Not scored

Note:

CFV - Containment Factor Value

Description of Other Possible Sources: 

Historical Releases of Chlorinated Solvents from Other Possible Operations: Historical releases of 

chlorinated solvents are possible from the operations discussed below.

Wampler Buick/GMC at 507 and 515 N. Elm Street): Ohio EPA identified two possible source areas 

of the VOC contamination (Ref. 6, p. 6): the Wampler Buick/GMC facility and the Hobart-Lytle Road 

landfill (Ref. 6, p. 6). The Hobart-Lytle Road Landfill is discussed further in the “Attribution” section of 

this HRS documentation record. The Ohio EPA collected direct-push ground water samples in and around 

the Wampler Buick/GMC location in 1997 (Ref. 5, p. 6). Findings from a combined PA/SI confirmed 

that the West Troy Aquifer and the West Well Field are contaminated with VOCs and found that the 

Wampler Buick/GMC facility is a possible source of the PCE in Troy production well 12W (Ref. 5, p. 

15). PCE has not been detected in ground water upgradient from these properties (Ref. 6, p. 6).

The ESI focused on 507 and 515 N. Elm Street on the east side of N. Elm Street just north of the City of 

Troy corporation limits (Ref. 6, p. 5). Ohio EPA’s contractor, Tetra Tech, advanced 11 direct-push 
24

borings at the properties to approximately 44 feet bgs (Ref. 6, p. 8). Three water samples were collected 

from 10 of the 11 borings at the following approximate depths: 20 to 24, 32 to 36, and 40 to 44 feet bgs 

(Ref. 6, p. 8). Two water samples also were collected from GP-86B at 32 to 36 and 40 to 44 feet bgs

(Ref. 6, p. 8). The highest concentrations of PCE were found in borings GP-84 (41 μg/L) at 20 to 24 feet 

bgs and GP-86B (32 μg/L) at 32 to 36 feet bgs (Ref. 6, p. 8). As part of the ESI, Tetra Tech installed five 

monitoring wells (OEPA-14, OEPA-15, OEPA-16, OEPA-17, and OEPA-18) at 507 and 515 N. Elm 

Street (Ref. 6, p. 10). The well locations and the screened intervals were based on the direct-push 

sampling results, with the goal of verifying the previous detections of PCE and establishing background 

concentrations (Ref. 6, p. 10). The five new monitoring wells, two upgradient monitoring wells owned by 

the City of Troy, two existing monitoring wells at 515 N. Elm Street, and city production wells 4W and 

12W were sampled (Ref. 6, p. 10). The highest concentration of PCE was found in monitoring well 

OEPA-17 at 21 μg/L (Ref. 6, p. 10). PCE was found in city well 12W at 5.7 μg/L (Ref. 6, p. 10). The 

pattern of detections from this and past investigations suggests that a release of PCE may have occurred 

in the vicinity of the former Wampler Buick/GMC facility at 507 and 515 N. Elm Street in Troy (Ref. 6, 

p. 12).

Troy Filler Metals Operation: The Troy Filler Metals Operation at 101 Trade Square East is located 

west of the Wampler Buick/GMC properties and PW-12W and has a history of solvent use, including use 

of chlorinated compounds (Ref. 8, p. 17). The Troy Filler Metals Operation manufactures welding and 

soldering equipment and is a Resource Conservation and Recovery Act (RCRA) large-quantity generator 

(LQG) (Ref. 8, p. 12). Waste codes F002, F003, and F005, which include chlorinated solvents, are 

documented in biennial RCRA reports for multiple years of operation (Ref. 8, p. 11). The Troy Filler 

Metals Operation is approximately 3,000 feet west-northwest of PW-12W (Ref. 8, pp. 11, 12). There are 

ground water data gaps for the areas west of the Wampler Buick/GMC properties and along and on both 

sides of Morgan’s Ditch. A ground water sample collected south of Morgan’s Ditch in 1997 contained 

PCE, and this finding may indicate a source located west of the Wampler Buick/GMC properties (Ref. 8, 

pp. 16, 17; 8A, pp. 19, 20, 25, 36, 72, 73). The Troy Filler Metals Operation is upgradient of PW-12W

(Ref. 8, p. 12). 

Additional Possible Sources:

A total 108 possible sources are identified in the Source Water Assessment and Protection Program 

Update (SWAP) (Ref. 9, p. 31). The 108 facilities described in the SWAP were identified using three 

methods (Ref. 9, p. 26). First, local, state, and national, and proprietary environmental databases 

were searched for the area encompassed by the SWAP boundary (Ref. 9, p. 26). Aerial 
25

photographs and parcel maps from the Miami County Auditor were used to help locate the facilities 

identified in the environmental databases and to ascertain whether any changes in ownership or land use 

occurred since the database entry was recorded (Ref. 9, p. 26). Once the facilities from the environmental 

databases were located, a windshield survey was conducted to confirm the location, existence, and 

ownership of the facilities and to locate any other facilities not identified in the environmental databases 

(Ref. 9, p. 26). Finally, historical aerial photos and USGS quadrangle maps were evaluated to identify 

changes in historical land use and to aid in the identification of the historical facility locations (Ref. 9, p. 

26).

Regional ground water flow is south following the Great Miami River valley (Ref. 8, p. 16). Based on 

this regional flow out of 108 possible sources identified in SWAP approximately 9 possible sources are 

potentially upgradient of the City of Troy west well field (Ref. 9, p. 135). Out of 9 facilities, two 

facilities located at 507 North Elm Street and 515 North Elm Street are already described in this 

documentation record (Wampler Buick/GMC); PCE, TCE and cis-1,2 DCE were not detected at one 

facility (Hobart Brothers Lagoon); one facility located at 542 North Elm Street does not appear to have 

used PCE, TCE or cis-1,2 DCE; the remaining five facilities are summarized below as possible sources

[there is no known analytical information available to conclusively identify or refute any of these 

facilities as a source(s)]:

1. The Re-store: The Re-store is located at 500 North Elm Street, in Troy, Ohio. The Re-store 

sells used furniture, appliances, and building materials (Ref. 9, p. 87). A Budget truck trailer, 

and moving equipment rental business is also operated from the facility. Fleet vehicles are 

stored and maintained at this location (Ref. 9, p. 87). The property formerly housed the Paint 

Strippers of Troy Company (Ref. 9, p. 87). Potential contaminants at this location include 

automotive wastes, fluids, lubricants, paints, paint thinners, lacquers, varnishes and other 

painting chemicals (Ref. 9, p. 87). The SWAP facility ID and location is provided in 

Reference 9, pages 113 and 135. The SWAP facility ID for The Re-store is 99 (Ref. 9, p. 

113). This facility is located northwest of the municipal well 12W (Ref. 9, p. 135).

2. Webster’s Auto: Webster’s Auto repair is located at 525 North Elm Street, Troy, Ohio (Ref. 

9, p. 90). Webster Auto is an automotive service center and collision repair shop (Ref. 9, p. 

90). Several plastic drums were observed in the rear of the property (Ref. 9, p. 90). Potential 

contaminants from the facility include solvents, paints, and automotive waste oils, fluids, and 

lubricants (Ref. 9, p. 90). The SWAP facility ID and location is provided in Reference 9, 
26

pages 113 and 135. The SWAP facility ID for Webster Auto is 103 (Ref. 9, p. 113). This 

facility is located northwest of the municipal well 12W (Ref. 9, p. 135).

3. Miami County Garage: Miami County Garage is located at 670 Harrison Street, Troy, Ohio 

(Ref. 9, p. 90). The Miami County Board of Commissioners operates a garage at this location

for maintaining county vehicles (Ref. 9, p. 90). The property historically contained 

underground storage tanks (USTs) both at the west end of the garage and the east end of the 

garage near the Miami County Engineer’s Office (Ref. 9, p. 90). The type, number, and 

contents of the USTs are not reported (Ref. 9, p. 90). Suspected or confirmed releases 

occurred at the property with no further action being granted by Bureau of Underground 

Storage Tank Regulations for both ends of the facility (Ref. 9, pp. 90, 91). Potential 

contaminants from the facility include gasoline, diesel, kerosene, solvents, paints, automotive 

waste oils, fluids, and lubricants (Ref. 9, p. 91). The SWAP facility ID and location is 

provided in Reference 9, pages 113 and 135. The SWAP facility ID for Miami County 

Garage is 104 (Ref. 9, p. 113). This facility is located northwest of the municipal well 12W 

(Ref. 9, p. 135). Ground water samples were collected from six soil borings around the 

Miami County Garage (Ref. 8A, pp. 10, 17, 19). PCE was detected at concentrations of 1.9 

μg/L to 6 μg/L in three ground water samples collected from two boring locations (Ref. 8A, 

pp, 17, 19, 25).

4. Former Trojan Specialties: Former Trojan Specialties is located at 745 Harrison Street, Troy,

Ohio (Ref. 9, p. 91). A vacant commercial building is present at this location (Ref. 9, p. 91). 

Previously, Trojan Specialties was present at this location (Ref. 9, p. 91). While there 

appears to be no current usage of the building, the potential exists for contaminants associated

with historical usage of the building. This facility is not listed in any environmental database

(Ref. 9, p. 91). The SWAP facility ID and location is provided in Reference 9, pages 113 and 

135. The SWAP facility ID for Former Trojan Specialties is 105 (Ref. 9, p. 113). This

facility is located northwest of the municipal well 12W (Ref. 9, p. 135).

5. Action Tire Auto Center: Action Tire and Auto Center is located at 816 Harrison Street, 

Troy, Ohio (Ref. 9, p. 91). Action Tire and Auto Center is a tire shop and automotive service 

center (Ref. 9, p. 91). The property historically contained one or more USTs; however, the 

type, number, and contents of the USTs are not reported (Ref. 9, p. 91). The USTs have been 

removed and no further action status has been granted to the facility (Ref. 9, p. 91). The 

facility is also listed under OEPA’s underground injection control database, which indicates 
27

the presence of a heating/cooling well, storm runoff wells/drains, a septic system, motor 

vehicle disposal wells/drains, or other types of wells or drains used to direct fluids below 

ground (Ref. 9, pp. 91, 92). An above ground storage tank (AST) was observed in the rear of 

the property. The AST had no underlying secondary containment (Ref. 9, p. 92). Potential 

contaminants from the location include gasoline, diesel, solvents, automotive waste oils, 

fluids, and lubricants (Ref. 9, p. 92). The SWAP facility ID and location is provided in 

Reference 9, pages 113 and 135. The SWAP facility ID for Action Tire Auto Center is 106 

(Ref. 9, p. 113). This facility is located northwest of the municipal well 12W (Ref. 9, p. 135).

3.0 GROUND WATER MIGRATION PATHWAY

Geology and Hydrogeology

The Great Miami River overlies an extensive aquifer system composed of unconsolidated Pleistocene and 

Holocene sediments that partially fill a previously eroded valley carved into the underlying bedrock 

(Refs. 6, p. 7; 11, p. 18). Generally, the geology of the area consists of near-surface, presumably riverderived silt, sand, and gravel deposits underlain by glacial deposits of sand and gravel interbedded with 

till (Refs. 6, p. 7, 39, 41; 11, pp. 17, 18, 20, 21). In some areas, these outwash deposits are separated by 

glacial tills and lacustrine deposits (Refs. 9, p. 1895; 11, pp. 17, 20, 21). Traditionally, the Great Miami 

River valley has been called a two-aquifer system (Ref. 6, p. 7). However, because there is little evidence 

for a single, laterally extensive till unit separating two sand and gravel aquifers across the entire valley, it 

is best described as a single-aquifer system (Refs. 6, p. 7; 11, pp. 17, 18, 20, 21). The lower aquifer is 

semi-confined, and there is hydraulic communication between the shallow and deep aquifers through gaps 

in the confining unit and leakage across the confining unit (Refs. 9, p. 1895; 11, pp. 17, 18, 20, 21). In 

the area of the City of Troy’s well fields, the productive portion of the buried valley aquifer is composed 

of thick sequences of glacial outwash deposits (unconsolidated sands, gravels, silts, and clays) (Refs. 6, 

pp. 39, 41; 9, p. 1895; 11, pp. 17, 18, 20, 21). 

Leakance studies of the river bed conducted by Troy’s wellhead protection consultant have shown that the 

river discharges to the aquifer in the reach of the well field (Refs. 6, p. 7; 11, p. 19). This is probably due 

to the influence of the production wells and suggests that the recharge of the deeper sand and gravel 

deposits in which the city wells are screened is induced by ground water drawdown caused by pumping 

(Refs. 6, p. 7; 11, p. 19). The bedrock deposits that compose the buried valley walls are relatively 

impermeable compared to the sand and gravel aquifers (Refs. 11, p. 19). Water wells in the bedrock 

deposits generally yield less than 10 gpm (Refs. 11, p. 19).
28

Aquifer Interconnection

Hydraulic communication between the two aquifers generally is either directly through gaps in the 

confining unit (which is absent in some parts of the buried valley) or through leakage through the 

confining unit (Ref. 11, p. 18). In order to better understand surface and ground water interactions at the 

well fields, the riverbed hydraulic characteristics of the Great Miami River were investigated. This 

investigation revealed ground water flow to the river north of the West Well Field and surface water flow 

from the river to the ground water system adjacent to and south of both well fields. These findings 

suggest that recharge of the aquifers from the river is induced by ground water drawdown caused by 

pumping (Ref. 11, p. 19). The Panterra Corporation report includes a geologic cross section of the area 

(Refs. 11, pp. 20, 21). 

Two aquifer pump tests were conducted during the supplemental ESI to evaluate interconnectivity 

between the Wampler Buick/GMC wells on the west side of the Great Miami River and PW-12W on the

east side (Refs. 8, p. 5; 9a, pp, 1). The first pump test was conducted during the first week of June 2010 

(Ref. 8, p. 5). All West Well Field production wells were turned off for approximately 24 hours before 

pumping began at PW-12W in order to stress the aquifer (Ref. 8, p. 5). Water level readings were 

collected continuously during this time using pressure transducers (Refs. 8, p. 5; 9b; 9c; 9d; 9e, p. 1). A 

significant rainfall event occurred about midway through the pump test, causing potential bias in the 

results (Ref. 8, p. 5). Because the first pump test was potentially compromised by the rainfall event and 

river level changes, a second pump test was conducted between August 30 and September 2, 2010 (Refs. 

8, p. 5; 9a, pp.1, 2, 33-43). Production wells were sampled during this pump test in the same manner as 

during the first pump test (Ref. 8, p. 6). There is an obvious response in the observation wells [located at 

the former Wampler Buick/GMC property] when well 12W was pumping. Water levels in all four wells 

dropped at the start of the two tests and started immediately recovering at the end of the tests (Refs. 9, pp. 

1895-1896; 9a, pp, 1, 35-38, 41). The Ohio EPA DDAGW staff evaluated pump test results and 

concluded that hydraulic communication exists between the shallow sands and gravels on the west side of 

the Great Miami River and the deeper sands and gravels on the east side of the river where PW-12W is 

located (Refs. 8, p. 15; 9a, pp. 1, 9b; 9c; 9d; 9e, p.1 ). Pump tests conducted at City of Troy well PW-15 

in the East Well Field in 1994 and at both well fields in 2000 demonstrate communication between 

shallow and deep sand and gravel deposits and indicate that the capture zone of the well fields extends 

across the river (Ref. 8, p. 13). Therefore, the hydraulic interconnection between the upper and lower 

aquifer is well established and the lower and upper aquifer system is referred to as an unconsolidated 

aquifer.
29

Aquifer Discontinuity

As detailed on Table 6 below, the combined upper and lower aquifers were evaluated as one 

unconsolidated aquifer system. The Great Miami River does not entirely transect the upper aquifer. The 

geologic cross section of the Great Miami River on Figure 4 of the Panterra Corporation report shows that 

the Great Miami River does not entirely transect the upper aquifer at the West Troy Contaminated 

Aquifer (Ref. 11, pp. 20, 21). Figure 3 of the Panterra Corporation report shows the location of the cross 

section relative to the land surface (Ref. 11, p. 17). 

Figure 4 of the Panterra Corporation report shows a cross section running north to south in the vicinity of 

the West Troy Contaminated Aquifer (Ref. 11, pp. 20, 21). The plume and the City of Troy West Well 

Field are located near well 12W (see Figure 3 of Reference 11 for well locations and Figure 1 of this HRS 

documentation record for the general site location), and the site is nearest to the northern location of the 

cross section . The cross section shows that at the point where the cross section crosses Great Miami 

River, the upper aquifer is approximately 40 feet thick and the river depth (including the river valley) is 

shown as only 10 feet. Therefore, based on this cross section, the river does not entirely transect the 

upper or combined aquifers. 

Based on actual field measurements of the depth of the Greater Miami River at a U.S. Geological Survey 

(USGS) gauging station in the City of Troy on several dates from 2005 through 2007, the Great Miami 

River depth ranged from 1.40 to 10.40 feet deep at the station (Ref. 12, p. 3). This range of river depth, 

when compared to the thickness of the upper aquifer of 10 to 40 feet in the vicinity of the plume, supports 

the conclusion discussed above that the Great Miami River does not entirely transect either the upper or 

combined upper and lower aquifers. Table 6 below summarizes the aquifer characteristics.

TABLE 6

AQUIFER CHARACTERISTICS SUMMARY

Source No. Aquifer Type

Is Aquifer Continuous 

Within-4-Mile Target 

Distance Limit? Is Aquifer Karst?

1 Unconsolidated Yes No

3.1 LIKELIHOOD OF RELEASE

3.1.1 Observed Release

Aquifer Being Evaluated: Unconsolidated aquifer system (interconnected upper and lower sand and 

gravel aquifers)
30

Direct Observation: An observed release by direct observation to the ground water migration pathway has 

not been established at the West Troy Contaminated Aquifer. 

Chemical Analysis: 

Establishing an observed release through chemical analysis requires analytical evidence of a hazardous 

substance in a medium at a concentration significantly exceeding the background concentration. If the 

background concentration of a chemical is not detected (or is less than the detection limit), an observed 

release is established when a sample measurement equals or exceeds its own sample quantitation limit 

(SQL) and the background SQL. If the SQL cannot be established, the EPA contract-required 

quantitation limit (CRQL) should be used instead of the SQL (Ref. 1, Section 2.3, p. 51589). 

Background Levels:

- Background Level at Source 1 – Other -- Contaminant Plume 

Regional ground water flow is south following the Great Miami River valley (Ref. 8, p. 16). Ground 

water at Troy is part of the Great Miami River Buried Valley Aquifer System (Refs. 8, p. 16; 9, pp. 

128,129). Based on available ground water flow information, monitoring wells MW-C, MW-E and MWK are considered to be a background (upgradient) wells. Figure 3 shows the background sampling

locations. The contaminants of concern for the West Troy Contaminated Aquifer (PCE; TCE; and cis1,2-DCE) were not detected in ground water samples collected from the background monitoring well 

locations (Ref. 9, pp. 1602, 1603, 1722, 1723, 1725, 1726, 1728, 1729, 1731, 1732, 1734, 1735, 1737, 

1738, 1861, 1862). The absence of contaminants of concern in the ground water samples suggests that 

the background locations to the depth of approximately 140 feet bgs lie outside the area of contamination. 

Table 7 below summarizes background location information and the concentrations of contaminants of 

concern detected in ground water samples collected from each location. 
31

TABLE 7

BACKGROUND LOCATION AND CONCENTRATION INFORMATION

Location 

No. Aquifer

Well or 

Sampling

Depth

(feet bgs)

Well

Screen 

Interval or 

Screen 

Length

(feet)

Sample 

No.

Sampling 

Date

Hazardous 

Substance

Concentration 

Detected (μg/L)

CRQL

(μg/L) References

MW-E_S UC 25 15-125 E2509 7/19/2010 PCE 0.5 U 0.5 Refs. 6, p. 51; 9, 

pp. 1001, 1554,

1662-

1669,1674, 

1675, 1727-

1729, 1787, 

1930, 1949; 10, 

pp. 1, 2

TCE 0.5 U 0.5

cis-1,2-DCE 0.5 U 0.5

MW-E_I UC 70 15-125 E2508 7/19/2010 PCE 0.5 U 0.5 Refs. 6, p. 51; 

9, pp. 1001,

1554, 1662-

1669,1674, 

1675, 1730-

1732, 1787, 

1929, 1949; 10, 

pp. 1, 2

TCE 0.5 U 0.5

cis-1,2-DCE 0.5 U 0.5

MW-E_D UC 122 15-125 E2507 7/19/2010 PCE 0.5 U 0.5 Refs. 6, p. 51; 

9, pp. 1001, 

1504 -

1512,1517, 

1518, 1554 

1602-1605,

1787, 1931; 10, 

pp. 1, 2

TCE 0.5 U 0.5

cis-1,2-DCE 0.5 U 0.5

MW-K_S UC 35 140 E2512 7/19/2010 PCE 0.5 U 0.5 Refs. 9, pp. 

898, 1554, 1787, 

1820-1825, 

1826, 1827, 

1844, 1861-

1863, 1917,

1949; 10, pp. 1,

2

TCE 0.5 U 0.5

cis-1,2-DCE 0.5 U 0.5

MW-K_I UC 75 140 E2511 7/19/2010 PCE 0.5 U 0.5 Refs. 9, pp. 898,

1554, 1662 -

1669,1676, 

1677, 1721-

1723, 1787, 

1916, 1949; 10, 

pp. 1, 2

TCE 0.5 U 0.5

cis-1,2-DCE 0.5 U 0.5

MW-K_D UC 121 140 E2510 7/19/2010 PCE 0.5 U 0.5 Refs. 9, pp. 898, 

1554, 1662 -

1669,1676, 

1677, 1724-

1726, 1787, 

1926, 1949; 10, 

pp. 1, 2

TCE 0.5 U 0.5

cis-1,2-DCE 0.5 U 0.5
32

Location 

No. Aquifer

Well or 

Sampling

Depth

(feet bgs)

Well

Screen 

Interval or 

Screen 

Length

(feet)

Sample 

No.

Sampling 

Date

Hazardous 

Substance

Concentration 

Detected (μg/L)

CRQL

(μg/L) References

MW-C_S UC 25 15-61 E2506 7/19/2010 PCE 0.5 U 0.5 Refs. 6, p. 50; 

9, pp. 1001, 

1662-

1669,1674, 

1675, 1733-

1735, 1788, 

1927, 1949; 10, 

pp. 1, 2

TCE 0.5 U 0.5

cis-1,2-DCE 0.5 U 0.5

MW-C_D UC 50 15-61 E2505 7/19/2010 PCE 0.5 U 0.5 Refs. 6, p. 50; 

9, pp. 1001, 

1662-

1669,1674, 

1675, 1736-

1738, 1788, 

1928, 1949 ; 

10, pp. 1, 2

TCE 0.5 U 0.5

cis-1,2-DCE 0.5 U 0.5

Notes:

μg/L – Microgram per liter 

bgs – Below ground surface

CRQL – Contract-Required Quantitation Limit (Ref. 10, pp. 1 and 2) 

DCE - Dichloroethene

PCE – Tetrachloroethene

TCE – Trichloroethene

NA – Not Available

U – Analyte was analyzed for but was not detected above the reported sample quantitation limit (Ref. 9, pp. 1512, 

1669, and 1825)

UC – Unconsolidated aquifer

Contaminated Samples:

- Contaminated Samples at Source 1 – Contaminated Plume

Table 8 below summarizes the results for ground water samples contaminated with PCE collected from 

monitoring wells and public supply wells at the West Troy Contaminated Aquifer. Figure 3 of this HRS 

documentation record shows the sampling locations.

TABLE 8

CONTAMINATED SAMPLE INFORMATION

Location 

No. Aquifer

Well or 

Sampling

Depth

(feet bgs)

Well

Screen 

Interval

(feet)

Sample 

No.

Sampling 

Date

Hazardous 

Substance

Concentration 

Detected (μg/L)

CRQL

(μg/L) References

OEPA-14 UC 44 39-44 E2495 7/21/10 PCE 8.7 0.5 Refs. 6, p. 45; 

9, pp. 1000,
33

Location 

No. Aquifer

Well or 

Sampling

Depth

(feet bgs)

Well

Screen 

Interval

(feet)

Sample 

No.

Sampling 

Date

Hazardous 

Substance

Concentration 

Detected (μg/L)

CRQL

(μg/L) References

1504-1512, 

1579, 1785,

1905; 10, pp. 1,2

OEPA-16 UC 25 15-25 E2497 7/21/10 10 0.5 Refs. 6, p. 47; 9, 

pp. 1000, 1504-

1512, 1585, 

1785, 1907; 10, 

pp. 1,2

OEPA-17 UC 34 29-34 E2498 7/21/10 18 0.5 Refs. 6, p. 48; 9, 

pp. 1000, 1504-

1512, 1588, 

1785, 1932; 10, 

pp. 1,2

PW-12W UC 86 66-86 E2500 7/21/10 5.2 0.5 Refs. 6, pp. 38-

39; 9, pp. 1504-

1512, 1591, 

1785, 1911; 10, 

pp. 1,2

W-3 UC 33.20 NA E2518 7/22/10 7.1 0.5 Refs. 9, pp. 

1504-1512, 

1519-1520, 

1556, 1923; 

10, pp. 1, 2

W-8 UC 16.59 7.6-17.5 E2522 7/22/10 3.9 0.5 Refs. 9, pp. 

1001, 1504-

1512, 1557, 

1631, 1921; 10, 

pp. 12

W-OB UC 34.45 NA E2521 7/22/10 6.5 0.5 Refs. 9, pp. 

1504-1512, 

1557, 1628, 

1919; 10, pp. 1, 

2

RW-5 UC NA NA E2529 7/21/10 9.1 0.5 Refs. 9, pp. 

1820-1825, 

1845, 1875, 

1900; 10, pp. 1,2

PW-12W UC 86 66-86 E2500 7/21/10 TCE 0.81 0.5 Refs. 6, pp.38, 

39; 9, pp. 1504-

1512 ,1591 

1785, 1911; 10, 

pp.1, 2

PW-12W UC 86 66-86 E2500 7/21/10 Cis-1,2-

DCE

1.1 0.5 Refs. 6, pp.38, 

39; 9, pp. 1504-

1512, 1590, 

1785, 1911;10, 

pp.1, 2
34

Notes:

μg/L – Microgram per liter 

bgs – Below ground surface

CRQL – Contract-Required Quantitation Limit (Ref. 10, pp. 1 and 2) 

DCE - Dichloroethene

PCE – Tetrachloroethene

TCE - Trichloroethene

NA – Not Available

U – Analyte was analyzed for but was not detected above the reported sample quantitation limit (Ref. 9, pp. 1512, 

1669, and 1825)

UC – Unconsolidated aquifer

The background and downgradient monitoring well samples were collected within the same timeframe 

(between July 19 and 22, 2010) (Ref. 9, pp. 1904-1937). The samples were collected with peristaltic and 

bladder pumps using a low-flow sampling technique (Ref. 9, pp. 1904-1937). The ground water samples 

were collected after the following field parameters had stabilized: pH, conductivity, dissolved oxygen 

(DO), temperature, oxidation-reduction potential, and turbidity (Ref. 9, pp. 1904-1937). The samples 

were analyzed by the U.S. EPA CLP) for VOCs using same method (Ref. 9, pp. 1504-1512). 

The ground water samples from private and public wells collected on July 21, 2010, are considered in this 

HRS documentation record (Ref. 9, pp. 1908-1912). The samples were collected on the same day by the 

same sampler (Ref. 9, pp. 1908-1912). The samples were analyzed by the U.S. EPA CLP for VOCs (Ref. 

9, pp. 1504-1512, 1820-1825).

West Troy Contaminated Aquifer Plume Releases (Contaminated Plume):

The West Troy Contaminated Aquifer plume has received releases from unidentified source(s). Releases 

associated with the plume area were detected through chemical analysis of ground water samples 

collected from residential, monitoring, and municipal wells. Analytical results for ground water samples 

collected from the plume area document observed releases to ground water, primarily of PCE; TCE; and 

cis-1,2-DCE (see Table 2, Contaminated Sample Information). As discussed in Section 3.1.1 above, if 

the background concentration of a chemical is not detected (or is less than the detection limit), an 

observed release is established when a sample measurement equals or exceeds its own SQL and the 

background sample concentration. If the SQL cannot be established, the EPA CRQL should be used 

instead of the SQL (Ref. 1, Section 2.3, p. 51589). VOCs were not detected in background wells, so all 

detected VOC concentrations exceeding the SQL qualify as observed release.

Attribution:

The West Troy Contaminated Aquifer ground water plume includes PCE from unidentified source(s). 

The plume also contains TCE and cis-1,2-DCE, which are biodegradation products of PCE (Ref. 13, pp. 
35

2,5). PCE; cis-1,2-DCE; and TCE do not exist naturally and are manmade chemicals (Refs. 20, p. 2; 21, 

p. 1; 22, p. 1; 23, p. 1). Significant ground water sampling has been performed to identify sources of the 

PCE contamination, but no sources have yet been conclusively identified. During the PA/SI, the Ohio 

EPA advanced four direct-push soil borings. Ground water samples were collected from 4 monitoring 

wells at the Earhart Petroleum property, 4 monitoring wells at the Hobart Lagoon, 6 city monitoring 

wells, and 11 monitoring wells at the Wampler Buick/GMC facility (Ref. 6, p. 6). Troy production wells 

4W and 12W also were sampled (Ref. 5, p. 7). PCE was detected in ground water samples from the 

Wampler Buick/GMC location (Ref. 5, pp. 8, 12, and 13). PCE was also detected in Troy production 

well 12W (Ref. 5, pp. 8, 13). The combined PA/SI identified the Wampler Buick/GMC property as a 

possible source of the PCE in Troy production well 12W (Ref. 5, p. 15).

The ESI focused on the two properties at 507 and 515 N. Elm Street located on the east side of N. Elm 

Street just north of the City of Troy corporation limits (Ref. 6, p. 5). The properties are approximately 

650 feet west of the Great Miami River and 1⁄4 mile northwest of well 12W (Ref. 6, p. 5). The property at 

507 N. Elm Street contains a building used by an automobile repair business (Ref. 6, p. 5). The property 

at 515 N. Elm Street contains one building originally a drive-in restaurant and presently used as an office 

for a used-car dealership (Ref. 6, p. 5). Both properties are mostly covered with asphalt or gravel except 

for areas beneath the buildings (Ref. 6, p. 5). Ohio EPA’s contractor, Tetra Tech, advanced 11 directpush borings at the properties to approximately 44 feet bgs (Ref. 6, p. 8). Three water samples were 

collected from 10 of the 11 borings at the following approximate depths: 20 to 24, 32 to 36, and 40 to 44 

feet bgs (Ref. 6, p. 8). Two water samples also were collected from GP-86B at 32 to 36 and 40 to 44 feet 

bgs (Ref. 6, p. 8). PCE was detected at several depths in ground water samples collected from 10 soil 

boring locations, (Ref. 6, pp. 8 and 9). As part of the ESI, Tetra Tech installed five monitoring wells. 

The five new monitoring wells, two upgradient monitoring wells owned by the City of Troy, two existing 

monitoring wells at 515 N. Elm Street, and city production wells 4W and 12W were sampled (Ref. 6, p. 

10). PCE was detected in samples from seven monitoring wells and public supply well 12W (Ref. 6, pp. 

18, 19, 30, 32, 34). The pattern of detections from this and past investigations suggests that a release of 

PCE has occurred in the vicinity of the former Wampler Buick/GMC location at 507 and 515 N. Elm 

Street in Troy (Ref. 6, p. 12). An actual source of PCE contamination was not determined during the ESI. 

During Phase I of the supplemental ESI, five public wells in the West Well Field were sampled before 

and after the pump test (Ref. 8, p. 5). During Phase 2 of the supplemental ESI, 5 West Well Field 

production wells, 24 monitoring wells, and 5 private production wells were sampled (Ref. 8, p. 6). 

Ground water sampling results confirmed that West Well Field wells PW-12W and PW-3W are 

contaminated with VOCs (Ref. 8, p. 16). PCE was detected at concentrations exceeding its MCL in PW-
36

12W. TCE, DCE, and TCA were detected in PW-12W at concentrations below their respective MCLs 

(Ref. 8, p. 16). DCE was detected in PW-3W for the first time in supplemental ESI samples, but all 

detections were below the DCE MCL (Ref. 8, p. 17). TCA was detected in samples from two private 

production wells (non-potable) on the west side of the Great Miami River (Ref. 8, p. 17). Samples from 

monitoring wells at the Wampler Buick/GMC properties contained VOCs at concentrations similar to 

those detected in 2005. The highest detection of PCE was 18 μg/L in OEPA-17 (Ref.9, p. 1941). Ohio 

EPA DDAGW staff evaluated pump test results and concluded that hydraulic communication exists 

between the shallow sands and gravels on the west side of the Great Miami River and the deeper sands 

and gravels on the east side of the river where PW-12W is located (Refs. 6, pp. 7, 11; 8, pp. 14, 16). The 

Wampler Buick/GMC properties could not be confirmed as the actual source of contamination (Ref. 8, p. 

17). No source area was identified because of the lack of definitive information on which to base source 

area soil sampling (Ref. 8, p. 17). The City of Troy minimized pumping PW-12W and blended water 

from both well fields to reduce VOC concentrations to below detectable limits in finished water (Ref. 8, 

p. 17). 

Soil samples collected in 1999 by ITW-Hobart at the Hobart-Lytle Road landfill, located about 4,600 feet 

northwest of the West Troy Contaminated Aquifer plume, were found to be contaminated with solvents, 

including TCE. Soil samples collected at the landfill in 2000 had detections of PCE and TCE (Ref. 5, p. 

7). Ground water samples taken by Ohio EPA in 2001 from a property south and east of the landfill 

showed contamination with benzene, ethyl benzene and xylene, but not PCE, TCE or 1,2-cis DCE (Ref. 5, 

p. 7). Therefore, at this time, the Hobart-Lytle Road landfill is not considered as a possible source for the 

ground water contamination in the plume.

Based on the investigations performed on several potential source areas, the ground water contamination 

source cannot be identified or reasonably attributed with confidence. Because the source is a 

contaminated ground water plume with no positively identified source of contamination, no separate 

attribution is required (Ref. 1, Section 3.1.1, p. 51595).

Hazardous Substances Released: 

The following hazardous substances are present in the observed release:

• PCE

• TCE

• cis-1,2-DCE 

Ground Water Observed Release Factor Value: 550
37

3.1.2 Potential to Release 

As specified in the HRS, because an observed release has been established for the aquifer, the potential to 

release is not scored (Ref. 1, Section 3.1.2, p. 51595).

3.2 WASTE CHARACTERISTICS 

The primary hazardous substance in the ground water plume impacting the City of Troy West Well Field 

is PCE. The contamination is described as a ground water plume with no identified source. PCE was

detected in several wells at concentrations exceeding the background levels. Ground water samples 

collected from municipal well PW-12W have been shown to be impacted by PCE, TCE and DCE (Refs. 

6, pp. 6, 11; 5, pp. 5, 13). The released substances are believed to be from an unknown source or sources 

west-northwest of the municipal wells. 

3.2.1 Toxicity/Mobility 

All hazardous substances listed in Table 9 below are documented in ground water samples collected from 

the West Troy Contaminated Aquifer. These hazardous substances were detected at concentrations 

significantly exceeding background levels. 

TABLE 9

OBSERVED RELEASE AND TOXICITY/MOBILITY SUMMARY

Hazardous

Substance

Toxicity 

Factor 

Value

Mobility 

Factor 

Value

Does Hazardous 

Substance Meet 

Observed Release 

Criteria?

Toxicity/ 

Mobility Reference

PCE 100 1 Yes 100 Refs. 1, Sections 3.2.1.1, 

3.2.1.2, and 3.2.1.3, pp. 

51601, 51602; 2, pp. A335, A-336, 1-5

TCE 1000 1 Yes 1000

cis 1,2-DCE 1000 1 Yes 1000 Refs. 1, Sections 3.2.1.1, 

3.2.1.2, and 3.2.1.3, pp. 

51601, 51602; 2, p. A-134

Notes:

DCE – Dichloroethene

PCE – Tetrachloroethene

TCE - Trichloroethene 

Because an observed release to the ground water migration pathway has been established, a mobility 

factor of 1 is applied to the hazardous substances released (Ref. 1, Section 3.2.1.2, p. 51601). As shown 

in Table 9 above, the toxicity/mobility factor value for TCE is 1000. The Toxicity/Mobility Factor Value 

of 1000 is assigned based on Table 3-9 of the HRS (Ref. 1, Section 3.2.1.3, p. 51602).
38

Toxicity/Mobility Factor Value: 1000

3.2.2 Hazardous Waste Quantity

Table 10 below summarizes the hazardous waste quantity information for the West Troy Contaminated 

Aquifer.

TABLE 10

HAZARDOUS WASTE QUANTITY SUMMARY

Source No. Source Name Source Type Source Hazardous Waste 

Quantity

1 Ground Water Plume Other Unknown but > 0

The West Troy Contaminated Aquifer has been scored as a contaminated ground water plume with no 

identified source. According to Section 2.4.2.2 in the HRS (Ref. 1, p. 51592), if any target sample for the 

migration pathway is subject to Level I or Level II concentrations and the hazardous constituent quantity 

is not adequately determined, the Hazardous Waste Quantity Factor Value for that pathway should either 

be assigned the value from Table 2-6 (Ref. 1, p. 51591) or a value of 100, whichever is greater. Because 

Level I concentrations were detected in samples from a drinking water well (see Section 3.3.2.2 of this 

HRS documentation record), a Hazardous Waste Quantity Factor Value of 100 is assigned to the ground 

water pathway. 

Hazardous Waste Quantity Factor Value: 100

(Ref. 1, Section 2.4.2.2, p. 51592)

3.2.3 Waste Characteristics Factor Category Value

As specified in the HRS (Ref. 1, Section 3.2.3, p. 51602), the Hazardous Waste Quantity Factor Value of 

100 is multiplied by the highest Toxicity/Mobility Factor Value of 1,000, resulting in a product of 

100,000 (1.0E+05). Based on this product, a Waste Characteristics Factor Category Value of 18 is

assigned from Table 2-7 of the HRS (Ref. 1, Section 2.4.3.1, p. 51592). The highest Toxicity/Mobility 

Factor Value of the substances listed in Section 3.2.1 of this HRS documentation record is for TCE and 

cis-1,2-DCE.

Toxicity/Mobility Factor Value: 1000

Hazardous Waste Quantity Factor Value: 100 
39

Toxicity/Mobility Factor Value (1000) × Hazardous Waste Quantity Factor Value (100) =

10,000 = 1 × 105

Waste Characteristics Factor Category Value: 18

(Ref. 1, Table 2-7, p. 51592)

3.3 TARGETS

A total of 10 municipal wells are located within the 4-mile-radius Target Distance Limit (TDL) from the 

center of the plume (Refs. 14, p. 1; 15, p. 1; 16, p. 1). The 4-mile-radius TDL is shown in Reference 28. 

The primary municipal well of concern is operated by the City of Troy municipal water system (Ref. 6, 

pp. 5, 6). One municipal well (PW-12W) operated by the City of Troy is within the West Troy 

Contaminated Aquifer and is impacted by the hazardous substances of concern (Tables 7 and 8). The 

targets evaluated for the ground water migration pathway are summarized below.

Level I Concentrations

Level I concentrations have been documented in one City of Troy public supply well (PW-12W) shown in 

Table 11 below. 

TABLE 11

LEVEL I CONCENTRATIONS 

Sample ID

Hazardous 

Substance

Hazardous

Substance 

Concentration 

(μg/L)

Benchmark 

Concentration 

(μg/L) Benchmark

References 

for 

Benchmark

E2500

(PW12W)

PCE 5.2 5.0 Maximum 

Contaminant 

Level (MCL)

Ref. 2, p. A336

Notes: 

See Table 8 for concentrations detected in the drinking water well samples.

μg/L = Microgram per liter

ID - Identification

PCE – Tetrachloroethene

3.3.1 Nearest Well

Well ID: PW-12W

Level of Contamination (I, II, or potential): Level I
40

Because actual contamination at Level I concentrations has been documented, a nearest well factor value 

of 50 is assigned (Ref. 1, Section 3.3.1, Table 3-11, p. 51603). 

Nearest Well Factor Value: 50

(Ref. 1, Table 3-11, p. 51603)

3.3.2 Population

3.3.2.1 Level of Contamination

The City of Troy municipal system has approximately 10,600 service connections and supplies to the City 

of West Milton and Miami County Public Water System (PWS) (Ref. 17, p. 2). The 10,600 City of Troy 

service connections include one service connection to the City of West Milton and one service connection 

to the Miami County PWS (Ref. 17, p. 2). The City of West Milton has approximately 2,066 service 

connections, and the Miami County PWS has approximately 1,442 service connections (Refs. 19, p. 1; 24, 

p. 1). Therefore, the total number of service connections served by City of Troy water system is 14,106 

(10,600 - 2 + 2,066 + 1,442). According to the U.S. Census Bureau, there are approximately 2.52

persons per household in Miami County, Ohio (Ref. 18, p. 1). Therefore, the total estimated population 

served by the City of Troy water system is 35,547 (14,106 total service connections × 2.52 persons per 

household for Miami County). The City of Troy water system has 10 municipal wells (Ref. 17, p. 1). 

The water pumped from these wells is blended (Ref. 17, p. 1). Between October 2010 and August 2011,

PW-12W has been out of service due to contamination (Refs. 17, p. 1; 17a, p.1). However, PW-12W was 

put back in service in August 2011 because OEPA was concerned that without this well running at least at 

a reduced flow, the contamination noted in that well might be drawn into other wells (Ref. 17a, p. 1). 

The City of Troy Water Department provided the annual pumping rate for each municipal well for 2010

(Ref. 16, p. 2). Based on these data, Table 12 below summarizes the annual pumping rates (Ref. 16, p. 2):

TABLE 12

ANNUAL MUNICIPAL WELL PUMPING RATES

Well ID Annual Pumpage 2010, Million 

Gallons Percentage Pumpage (%)

3W 184.2 13.1

4W 107.3 7.6

16 145 10.3

12W 10.7 0.8
41

19 119.5 8.5

14 129.7 9.2

18 147.1 10.4

4E 222.6 15.8

13 154.1 10.9

17 189.9 13.5

Total 1410.1 100.11

Note:

1 – Total exceeds 100 percent due to rounding

Source: Refs. 16, p.2; 26, p. 1

ID - Identification

Based on the annual pumping rates for 2010, no municipal well supplied more than 40 percent of the 

system’s total water. Therefore, the population of 35,547 is apportioned equally to each municipal well

(Ref. 1, Section 3.3.2, p. 51603; Ref. 24, pp. 1). Based on this approach, the population served by each 

well is approximately 3,554 (35,547 divided by 10 municipal wells). 

3.3.2.2 Level I Concentrations

Level I Population Targets

For municipal well PW-12W, the population allocated is 3,554. Contamination of the Level I well is 

documented in Tables 2 and 8. Table 13 summarizes the Level I population affected by PW-12W, which 

is completed in the unconsolidated aquifer (Ref. 17, p. 3). 

TABLE 13

LEVEL I POPULATION

Level I Well Aquifer Population Reference

PW-12W Unconsolidated 3,554

Ref. 1, 

Section 

3.3.2.2, p. 

51603

Sum of Population Served by Level I Wells: 3,554

Sum of Population Served by Level I Wells × 10 = 35,540 (Ref. 1, Section 3.3.2.2, p. 51603). 

Level I Concentrations Factor Value: 35,540

3.3.2.3 Level II Concentrations

Level II Population Targets
42

Based on the HRS (Ref. 1, Section 3.3.2.3, p. 51603), no targets are subject to Level II contamination.

Level II Concentrations Factor Value: 0.

3.3.2.4 Potential Contamination

Because Level I concentrations provide the maximum score for the ground water migration pathway, the 

potential contamination factor is not scored for this HRS documentation record. Although potential 

contamination is not scored, there is a concern about populations that could be exposed to contaminated 

drinking water.

Potential Contamination Factor Value: Not Scored

3.3.3 RESOURCES

Ground water within the 4-mile-radius TDL is used for commercial food preparation (Ref. 17, p. 3). 

Therefore, the Resources Factor is assigned a value of 5 (Ref. 1, Section 3.3.3, p. 51604).

Resources Factor Value: 5

3.3.4 WELLHEAD PROTECTION AREA

The wellhead protection area factor is not scored because it does not impact the overall score.

Wellhead Protection Area Factor Value: 0

3.3.5 CALCULATION OF TARGETS FACTOR CATEGORY VALUE 

The total target factor category value is the sum of the nearest well, population, resources, and wellhead 

protection area values (Ref. 1, Section 3.3.5, p. 51604). The total target factor category value for the site 

is 50 (nearest well) + 35,540 (population) + 5 (resources) + 0 (wellhead protection area) = 35,595.