HRS DOCUMENTATION RECORD COVER SHEET

Name of Site: Valley Pike VOCs 

EPA ID No. OHN000510489 

Contact Persons 

Site Investigation: Patrick Hamblin, National Priorities List Coordinator 

 U.S. Environmental Protection Agency, Region 5 

 77 West Jackson Boulevard 

 Chicago, IL 60606 

 312-886-6312 

Documentation Record: Sandy Anagnostopoulos, Project Manager 

 Tetra Tech, Inc. 

 1 South Wacker Drive, Suite 3700 

 Chicago, IL 60606 

 312-201-7723 

Pathways, Components, or Threats Not Scored 

The surface water migration, soil exposure, and air migration pathways were not scored in this Hazard 

Ranking System (HRS) documentation record because the ground water migration pathway achieves an 

HRS site score sufficient for inclusion on the National Priorities List (NPL). The nearest surface water 

body is located within 0.5 mile of the site (Ref. 3). Contaminated soil and soil vapor samples collected at 

and in the vicinity of the site indicate the presence of hazardous substances (Ref. 15, p. 19). Due to the 

proximity of the site to potential targets for the surface water migration, soil exposure, and air migration 

pathways, these pathways may be of future concern to the U.S. Environmental Protection Agency (EPA). 
1

HAZARD RANKING SYSTEM DOCUMENTATION RECORD

Name of Site: Valley Pike VOCs

Date Prepared: April 2016

EPA Region: 5

Street Address of Site*: 2949 Valley Pike (Figure 1)

City, County, State, Zip Code: Riverside, Montgomery County, Ohio 45404

General Location in the State: West-central part of Ohio (east of Dayton, Ohio)

Topographic Map: Dayton North, Ohio (Ref. 3)

Latitude: 39o47' 50" North

Longitude: 84o7' 57" West 

The latitude and longitude coordinates listed above were measured from observed release ground water 

sampling location MW-EPA-8 (Refs. 9; 10) (see Figure 4 of this HRS documentation record).

* 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, disposed, or 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 as to where the contamination has come to be located.

Pathway Pathway Score

Ground Water Migration 100.00

Surface Water Migration NS

Soil Exposure NS

Air Migration NS

HRS SITE SCORE 50.00

Note:

NS Not scored
2

WORKSHEET FOR COMPUTING HRS SITE SCORE

S Pathway S

2 Pathway

Ground Water Migration Pathway Score (Sgw) 100.00 10,000

Surface Water Migration Pathway Score (Ssw) NS NS

Soil Exposure Pathway Score (Ss) NS NS

Air Migration Pathway Score (Sa) NS NS

S

2

gw + S2sw + S2s + S2a 10,000

(S2

gw + S2sw + S2s + S2a) / 4 2,500

√ (S2

gw + S2sw + S2s + S2a) / 4 50.00

Note:

NS Not scored
3

HRS Table 3-1 –Ground Water Migration Pathway Scoresheet 

Aquifer Evaluated: Great Miami Buried Valley Aquifer System 

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) 1,000

5. Hazardous Waste Quantity (a) 10

6. Waste Characteristics 100 10

Targets:

7. Nearest Well 50 9

8. Population:

 8a. Level I Concentrations (b) 0

 8b. Level II Concentrations (b) 0

 8c. Potential Contamination (b) 5,326

 8d. Population (lines 8a + 8b + 8c) (b) 5,326

9. Resources 5 5

10. Wellhead Protection Area 20 5

11. Targets (lines 7 + 8d + 9 + 10) (b) 5,345

Ground Water Migration Score For An Aquifer:

12. Aquifer Score [(lines 3 x 6 x 11)/82,500]c100 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 
^_

Mullins Rubber Products, Inc.

Parcel Boundary

±

Date Saved: 2/4/2016 

"

Ohio

Valley Pike VOCs

2949 Valley Pike

Dayton, Montgomery County, Ohio

Figure 1

Site Location

Prepared For: US EPA Prepared By: Tetra Tech

EPA Contract No.: EP-S5-13-01 TDD No.: S05-0002-1410-011

2,000 0 2,000

Feet

Source: Ref. 15, p. 4.

USGS 7.5 Minute Topographic Quadrangle Map

Dayton North, OH 1996

Site

Location

Reference Map Legend

^_ Source No. 1 Location

Mullins Rubber Products, Inc.

Parcel Boundary

Coordinate System: GCS WGS 1984

Datum: WGS 1984

Units: Degree
Figure 2 Land Use Map is unavailable to be published in this document. To view this 

figure, please contact: EPA Region 5, Records Center l, 77 West Jackson Boulevard, 

Chicago, IL 60604 or the EPA HQ Docket Center, 1301 Constitution Ave, NW, 

Room 3334, Washington, DC 20004.
Figure 3 Source Locations Dry/Injection Well DW-2 and Other Possible Soil Source is 

unavailable to be published in this document. To view this figure, please contact: EPA 

Region 5, Records Center l, 77 West Jackson Boulevard, Chicago, IL 60604 

or the EPA HQ Docket Center, 1301 Constitution Ave, NW, Room 3334, Washington, 

DC 20004.
Figure 4 Ground Water Observed Release Well Locations is unavailable to be published 

in this document. To view this figure, please contact: EPA Region 5, Records Center l, 

77 West Jackson Boulevard, Chicago, IL 60604 or the EPA HQ Docket Center, 1301 

Constitution Ave, NW, Room 3334, Washington, DC 20004.
Figure 5 Valley Pike VOC Area of Concern is unavailable to be published in this 

document. To view this figure, please contact: EPA Region 5, Records Center l, 

77 West Jackson Boulevard, Chicago, IL 60604 or the EPA HQ Docket Center, 

1301 Constitution Ave, NW, Room 3334, Washington, DC 20004.
9

REFERENCES 

1. U.S. Environmental Protection Agency (U.S. EPA). 1990. Hazard Ranking System; Final Rule.

A complete copy of the Hazard Ranking System is available at:

http://semspub.epa.gov/src/document/HQ/174028. 14 December. 136 pages.

2. U.S. EPA. 2014. Superfund Chemical Data Matrix (SCDM) Query and Methodology. A

complete copy of SCDM is available at: http://www.epa.gov/superfund/superfund-chemical-datamatrix-scdm-query. Accessed on January 14, 2016. 4 pages.

3. Tetra Tech, Inc. (Tetra Tech). 1996. 4-Mile Radius. U.S. Geological Survey (USGS) 7.5 Minute

Series Topographic Quadrangle Map. Dayton North, Ohio 1996. Scale 1:24,000. 1 Map.

4. U.S. EPA. 2016. Superfund Site Search Results. U.S. EPA Website. Available at:

http://cumulis.epa.gov/supercpad/cursites/csitinfo.cfm?id=0510489&msspp=. Accessed on

March 23, 2016. 2 pages.

5. Auditor’s Data. Montgomery County, Ohio. Property Address: 2949 Valley Pike. Available at:

http://www.mcrealestate.org/search/commonsearch.aspx?mode=address. Accessed on March 26,

2015. 2 pages.

6. Mullins Rubber Products, Inc. Website. Available at: http://www.mullinsrubber.com/index.html.

Accessed on March 26, 2015. Excerpt. 4 pages.

7. Ohio Environmental Protection Agency (Ohio EPA). 2015. Mullins Rubber Products, Inc. Site

Reassessment Report. April. Excerpt. 94 pages. [Note: Appendix C, a 2015 Tetra Tech report,

is not included in Reference 7 because it is included as Reference 15 of this HRS Documentation

Record].

8. Ohio EPA. 2012. Mullins Rubber Products Expanded Site Inspection Report. February. 515

pages.

9. Thomas Keith Marsh, Surveyor. Annotated Well Survey for Contaminant Source Area

Investigation, Valley Pike VOC Site, April 7, 2015. Well Survey Dated October 16, 2014. 1

page.

10. Earth Point. State Plane Coordinate System Conversion. Available at:

http://www.earthpoint.us/StatePlane.aspx. Accessed on July 21, 2015. 2 pages.

11. Mullins Rubber Products, Inc. 2009. Response to Ohio EPA Request for Information Letter

Regarding Mullins Rubber Products, Inc. From William R. Mullins Jr., Vice President. To

George Strobel, Ohio EPA. 28 September. Excerpt. 11 pages.

12. Tetra Tech. 2015 and 2016. Electronic Mail Correspondence between Sandy Anagnostopoulos,

Tetra Tech, and Keshia Kinney, City of Dayton, OH, Regarding City of Dayton Water Supply.

April 16, 2015 to January 28, 2016. 4 pages.

13. City of Dayton. Source Water Protection Program Brochure. Available at:

http://www.daytonwater.org/uploads/docs/SWPA%20Brochure.pdf. Accessed on July 22, 2015.

12 pages.

14. Dinsmore & Shohl, LLP. 2013. Response to CERCLA 104e Letter Regarding Mullins Rubber

Products Site. From Timothy Hoffman, Counsel. To Grace Co, Enforcement Specialist, U. S.

EPA Region 5. 24 September. 63 pages.
10

15. Tetra Tech. 2015. Contaminant Source Area Investigation for Valley Pike VOC Site. Prepared

for U.S. EPA Region 5. 7 April. 217 pages.

16. Ohio EPA. 2015. Memo from Wendy Vorwerk, Ohio EPA, to Patrick Hamlin, U.S. EPA,

Regarding Mullins Rubber Products, Inc. Site Investigation Dry Well Sample Clarification.

December 10. 2 pages.

17. Ohio EPA. 2011. Site Inspection (SI) Report for Mullins Rubber Products, Inc. 23 February.

Excerpt. 191 pages.

18. Ohio EPA. 2013. Mullins Rubber Products, Inc. Supplemental Expanded Inspection Report.

August. 296 pages.

19. Tetra Tech. 2016. Project Note Regarding Conversion of Feet Below Ground Surface to Feet

Above Mean Sea Level. 5 January. 1 page.

20. Tetra Tech. 2016. Electronic Mail Correspondence between Sandy Anagnostopoulos, Tetra

Tech, Cathy Greulich, City of Dayton, and Keshia Kinney, City of Dayton. Regarding Location

of City of Dayton Water Department Production Wells and Well Head Protection Areas. Shape

Files Received by Electronic Mail Are Not Included as Part of the Reference. January 28 to

February 3. 2 pages.

21. Tetra Tech. 2014. Chain of Custody Forms for Contaminant Source Area Investigation for

Valley Pike VOC Site. Samples Collected for U.S. EPA Region 5. September through October.

9 pages.

22. USGS. 1999. Use of Environmental Tracers to Evaluate Ground-Water Age and Water-Quality

Trends in a Buried-Valley Aquifer, Dayton Area, Southwestern Ohio. Water-Resources

Investigation Report 99-4113. 87 pages.

23. USGS. 1998. Simulation of Ground-Water Flow, Dayton Area, Southwestern Ohio. WaterResources Investigations Report 98-4048. 64 pages.

24. ODNR. 2012. Geology of the Dayton Region in Core and Outcrop—A Workshop and Field Trip

for Citizens, Environmental Investigators, Geologists, and Educators. 62 pages.

25. USGS. 2000. Environmental Setting and Effects on Water Quality in the Great and Little Miami

River Basins, Ohio and Indiana. Water-Resources Investigations Report 99-4201. 110 pages.

26. CH2MHill. 2011. Final Report: Source Water Protection Delineation Model Update.

November. 38 pages.

27. Ground Water Consortium. GMBVA Information Page. Ground Water Consortium Website.

Available at: http://www.gwconsortium.org/gmbva-information-page.php. Accessed on

September 2, 2015. 2 pages.

28. Tetra Tech. 2016. Approximate Locations of MR-102S and MR-103. 1 page.

29. U.S. EPA. Designated Sole Source Aquifers in Region 5. Greater Miami Buried Aquifer, and

OKI Extension, Ohio. 1 page.

30. Miami Conservancy District. 2011. Water Resources Report for the Great Miami River

Watershed. 84 pages.
11

31. USGS. 1993. Hydrogeology, Simulated Ground-Water Flow, and Ground-Water Quality,

Wright-Patterson Air Force Base, Ohio. Water-Resources Investigation Report 93-4047. 160

pages.

32. City of Dayton Ohio. Well Field Protection Program. Available at:

http://water.cityofdayton.org/water/wellfield.asp. Accessed on September 8, 2015. 2 pages.

33. Tetra Tech. 2016. Project Note Regarding MRP Wells and Sample Location Names. 9 March.

10 pages.

34. Ohio EPA. 1996. Letter Regarding Ohio EPA’s Endorsement of the Dayton Well Field

Protection Program. From Michael G. Baker, Program Manager, Division of Drinking and

Ground Waters. To Mayor Michael R. Turner, City of Dayton. March 25. 1 page.

35. Pace Analytical Laboratories, Inc. 2015. Project Note Regarding Definition of Reporting Limits.

7 October. 1 page.

36. Paul’s Garage, Inc. 2013. Response to EPA Request for Information Letter Regarding Paul’s

Garage, Inc. From Charles Lovely. To Grace Co, EPA. 19 October. 1 page.

37. RCRA Info Search Results for Paul’s Garage, Inc. Available at:

http://aspub.epa.gov/enviro/rcrainfoquery_3.facility_information?pgm_sys_id=OHD041060385.

Accessed on January 13, 2016. 2 pages.

38. Ohio EPA. Underground Injection Control (UIC) Program. Available at:

http://www.epa.ohio.gov/ddagw/uic.aspx#114042767-class-v-wells. Accessed on October 7,

2015. 3 pages.

39. U.S. EPA. Annotated CERCLIS Search Results for Dayton, Ohio. Available at:

http://oaspub.epa.gov/enviro/fii_query_dtl.disp_program_facility?pgm_sys_id_in=OHN0

00510164&pgm_sys_acrnm_in=CERCLIS. Accessed on October 8, 2015. 6 pages.

40. Mullins Rubber Products, Inc. 2012. Response to Ohio EPA Request for Information Letter

Dated September 6, 2012 Regarding Closure of Class V Injection Wells at Mullins Rubber

Products, Inc. From William R. Mullins Jr., Vice President. To Lindsay Taliaferro II, Ohio EPA,

Division of Drinking and Ground Waters. 8 October. 5 pages.

41. Ohio EPA. 2012. Letter Regarding MRP Provide Analysis of Non-contact Cooling Water Prior

to the Non-contact Cooling Water Entering the On-site Injection Wells. From Valerie Orr,

Division of Drinking and Ground Waters. To William R. Mullins, Jr, MRP. 9 February. 3

pages.

42. Ohio EPA. 2014. Source Water Protection in Ohio Fact Sheet. Accessed at:

http://www.epa.state.oh.us/portals/28/documents/swap/swap_factsheet.pdf. April. 4 pages.

43. Ohio EPA. 2012. Letter Regarding Ohio EPA Agreement That MRP No Longer Needs to

Provide Analysis of Non-contact Cooling Water Prior to the Non-contact Cooling Water Entering

the On-site Injection Wells. From Lindsay Taliaferro, III, Division of Drinking and Ground

Waters. To William R. Mullins, Jr, MRP. 6 June. 2 pages.

44. Dinsmore & Shohl, LLP. 2012. Response to Ohio EPA Letter Regarding Mullins Rubber

Products, Inc. From Timothy D. Hoffman, Counsel. To Valerie J. Orr, Class V Coordinator,

Ohio EPA. 2 May. 1 page.
12

45. Tetra Tech. 2016. Project Note Regarding Ohio EPA SI and ESI Adjusted Contract Required

Detection Limits and Sample Quantitation Limits. January 25. 14 pages.

46. EPA. Office of Solid Waste and Emergency Response. Multi-Media, Multi-Concentration,

Organic Analytical Service for Superfund (SOM01.2). EPA Publication 540-FS-07-001, August

2007. 6 Pages.

47. Tetra Tech. 2016 Project Note Regarding Reporting Limits in Test America Analytical Data

Packages. January 26. 6 pages.

48. Tetra Tech. 2016. Approximate Distance to Nearest Well. 1 page.

49. Tetra Tech. 2016. Google Maps Search and Distance Measurement from Source 1 to Forest

Ridge Association Pool. 1 page.

50. Tetra Tech. 2016. Project Note Regarding Review of U.S. EPA and Ohio EPA Records Review.

January 5. 1 page.

51. U.S. EPA. 2016. Administrative Settlement Agreement and Order on Consent for Removal

Action. Respondents: Mullins Rubber Products, Inc. and Mullins Land Company, Inc. Docket

No. V-W-16-C-004. January 8. 31 pages.

52. U.S. EPA. 2015. Enforcement Action Memorandum: Determination of an Imminent and

Substantial Threat to Public Health and the Environment at the Valley Pike VOC Site, Riverside,

Montgomery County, Ohio (Site ID #C5U2). From Steve Renninger, On-Scene Coordinator. To

Richard C. Karl, Director, Superfund Division. June 26. 36 pages.
13 Site Description

SITE DESCRIPTION

For HRS scoring purposes, the Valley Pike VOCs site is composed of Source No. 1 (dry/injection well 

DW-2) located on the Mullins Rubber Products, Inc. (MRP) property, and an observed release of the 

volatile organic compounds (VOCs) tetrachloroethylene (PCE) and trichloroethylene (TCE) to the 

shallow sand and gravel zone of the Great Miami Buried Valley Aquifer System (GMBVAS) (Refs. 8, pp. 

144, 150, 153, 219, 234, 237; 15, pp. 152, 165, 167, 169, 171, 184, 186, 199, 201; 17, pp. 29, 30, 37, 103, 

122, 128; 33). 

The Valley Pike VOCs site is located at 2949 Valley Pike in Riverside, Montgomery County, Ohio (Ref. 

4, p. 1). Figure 1 of this HRS documentation record shows the location of the Valley Pike VOCs site. 

More specifically, the geographic coordinates, as measured from observed release ground water sampling 

location MW-EPA-8 (see section 3.1.1 of this HRS documentation record), located on the west edge of 

MRP, are latitude 39o 47' 50" north and longitude 84o 7' 57" west (Refs. 9; 10). The MRP property 

consists of one parcel of land covering 3.675 acres (Ref. 5). The Valley Pike VOCs site is located on the 

MRP property in a mixed industrial and residential area and is bordered to the north by Old Dominion 

Freight Lines, Inc., to the east by Rock Castle Storage and a single residence, to the south by Valley Pike, 

and to the west by Paul’s Garage and Towing (Ref. 8, p. 7) (see Figure 2 of this HRS documentation 

record). The EPA identification number, as recorded in the Superfund Enterprise Management System 

(SEMS) database, is OHN000510489 (Ref. 4, p.1). 

MRP is an active manufacturing facility presently producing molded heavy-duty truck trailer suspension 

bushings (Refs. 6, p. 2; 11, p. 2). MRP’s manufacturing process uses, and has historically used, TCE 

since 1968 (Refs. 14, p. 3; 15, p. 4). Prior to 2012, MRP used production wells completed in the deep 

zone of the sand and gravel aquifer as the water supply for non-contact cooling water for facility 

degreasers (Refs. 17, pp. 2, 12, 126, 127; 14, p. 4). Following circulation through the system, MRP 

pumped the used non-contact cooling water into dry/injection wells completed in the shallow zone of the 

sand and gravel aquifer (Refs. 17, pp. 2, 12, 128; 14, p. 4). Sampling data indicated that water from a 

deep production well used in the facility’s process as non-contact cooling water was contaminated with 

PCE and TCE. Sampling data further indicated that the same contaminants are present in water samples 

collected from Source No. 1, dry/injection well DW-2 located at MRP, that received the contaminated 

non-contact cooling water. 

An observed release of PCE and TCE to ground water is documented in the shallow zone of the 

GMBVAS by both direct observation and chemical analysis (see section 3.1.1 of this HRS documentation 

record) (Refs. 8, pp. 150, 153, 234, 237; 15, pp. 152, 165, 167, 169, 171, 184, 186, 199, 201; 17, pp. 29, 

30, 37, 103, 122, 126, 128; 33). Ground water underlying Source No. 1 became contaminated, at least in 

part, as a result of MRP discharging contaminated non-contact cooling water from the vapor degreasers 

into its dry/injection wells, including DW-2 (Refs. 8, pp. 144, 152, 153, 219, 237; 17, pp. 29, 30, 37). 

During September 2014, as part of the U.S. EPA Contaminant Source Area Investigation for Valley Pike 

VOCs site, six sub-slab vapor samples, VP-EPA-1, -2, -3, -4, -5, and -6, were collected below the MRP 

manufacturing building (Refs. 7, pp. 9, 10; 15, pp. 16, 17). PCE and TCE were detected at all six 

locations (Ref. 15, pp. 16, 17). The highest concentrations of both PCE and TCE were detected at sample 

locations VP-EPA-4, VP-EPA -5, and VP-EPA -6, located closest to the MRP degreaser area (Ref. 15, 

pp. 17, 36). Specifically, the highest concentration of TCE detected was 44,400 micrograms per cubic 

meter (μg/m3) in sample VP-EPA-5; and the highest concentration of PCE detected in sub-slab vapor 

samples was 3,550,000 μg/m3

in sample VP-EPA-4 (Refs. 7, pp. 10, 22; 15, pp. 17, 29, 36). Lower 

concentrations of PCE and TCE were detected at sample locations VP-EPA-1, VP-EPA-2, and VP-EPA3, located farther west, downgradient and sidegradient of the MRP degreaser area, towards the Paul’s 

Garage property line (Ref. 15, p. 17). The reported concentrations in several sub-vapor samples 

significantly exceeded Ohio Department of Health (ODH)/Agency for Toxic Substances and Disease 
14 Site Description

Registry (ATSDR) commercial sub-slab screening levels for PCE (250 μg/m3) and TCE (20 μg/m3) (Ref. 

15, p. 17). 

In addition, the highest concentrations of TCE and PCE were detected during the same investigation in 

soil and ground water samples collected at MW-EPA-8, which is downgradient from the MRP vapor 

degreaser area (see Figure 4 of this HRS documentation record) (Refs. 15, pp. 30, 99; 21, p. 2). 

OPERATIONAL AND REGULATORY HISTORY 

MRP began operations in 1942 as the Mullins Tire and Rubber Company (Refs. 6, p. 2; 11, p. 2). The 

primary operation at that time was retreading used tires (Refs. 6, p. 2, 7, p. 4). In 1954, the business 

expanded from tires into molding different types of rubber products (Ref. 6, p. 2). Since the mid-1960s, 

the company has focused on molding heavy-duty truck trailer suspension bushings (Ref. 6, p. 2). The 

MRP facility is currently owned by Mullins Land Company, Inc. (Ref. 14, p. 3).

As part of MRP’s manufacturing process, metal parts are degreased with TCE in two vapor degreasers 

before they are bonded with rubber parts (Refs. 6, p. 4; 14, p. 3). The vapor degreasers are located in the 

northwestern portion of the manufacturing area, near the north end of the building (Ref. 15, p. 4) (see 

Figure 3 of this HRS documentation record). Since 1968, MRP has used TCE for degreasing parts (Ref. 

14, pp. 3, 4). In 1994, MRP installed two vapor degreasers; non-contact cooling water from degreasing 

tanks associated with the manufacturing process discharged into a series of dry/injection wells on the 

northern portion of the MRP facility (Refs. 8, p. 24; 14, pp. 3, 4; 15, p. 41). In 2012, Ohio EPA told MRP 

that it could no longer use the dry/injection wells to receive the non-contact cooling water because of the 

presence of PCE in local ground water (Ref. 14, p. 4). In 2012, MRP installed a chiller unit and noncontact cooling water holding tanks for their closed-loop system (Ref. 40, pp. 1, 2). 

MRP used a total of seven wells, including the Source No. 1 dry/injection well DW-2, (referred to as 

“dry” wells) to manage non-contact cooling water, storm drainage, and boiler blowdown water (Ref. 15, 

pp. 4, 41). Although MRP refers to all of these structures as “dry wells,” a log for well DW-2 indicates 

that this well extended to 50 feet below ground surface (bgs), through an upper clay layer and into the 

sand and gravel aquifer below, and thus discharged water directly into the local aquifer (Refs. 15, p. 42; 

16, p. 1; 33, p. 4). This type of well (commonly referred to as an injection well) differs in construction 

from other wells known as “dry” wells in the site area that are used solely for stormwater management 

and that collect and allow surface drainage to infiltrate directly into the shallow subsurface through the 

vadose zone (Refs. 15, p. 4; 38). The MRP wells were considered Class V injection wells under the Ohio 

Underground Injection Control (UIC) Program (Refs. 14, p. 4; 15, p. 4). Permits were not issued, but the 

wells were registered with Ohio EPA (Ref. 15, p. 4). 

There are four production wells at MRP that are or have been used for non-contact cooling water for 

MRP’s rubber mixing mills and vapor degreasers (Refs. 8, pp. 2, 7, 467 to 469; 14, p. 4). The MRP 

active deep production well (130 feet deep, but cased to 120 feet bgs), at the east/central part of the 

property, formerly produced about 250 to 300 gallons per minute for 8 hours a day (Refs. 7, p. 3; 8, pp. 2, 

467). Currently, this production well is used infrequently to “top off” the closed loop system (Ref. 7, p. 

3). Two additional deep production wells are on standby (Ref. 7, p. 3). A fourth shallow well (50 feet 

deep) is damaged and is no longer used, but remains in place (Ref. 7, p. 3). All production wells are on 

the eastern side of the MRP building (Ref. 7, p. 3). 

MRP is required to report TCE usage annually to the Regional Air Pollution Control Agency (RAPCA) 

(Ref. 7, p. 4). After an anonymous source alleged the company was under-reporting the amount of 

solvents used, the Ohio EPA and RAPCA performed an unannounced inspection on May 14, 2001 (Ref. 

7, p. 4). RAPCA and Ohio EPA determined that MRP had under-reported its TCE usage, kept false 

records, and knowingly reported false data from 1995 to 2000 (Ref. 7, p. 4). From 1995 to 1999, the 
15 Site Description

combined emissions permit limit was 10,000 pounds per year (Ref. 7, p. 4). However, actual emissions 

were calculated and ranged from 17,679 pounds in 1996 to 38,556 pounds in 1997 (Ref. 7, pp. 4, 5). In 

January 2004, a seven-count criminal indictment was filed against MRP by the U.S. Attorney’s Office in 

Dayton, Ohio (Ref. 7, p. 5). 

Later the same year, William R. Mullins, President of MRP, pled guilty to making false statements in 

reporting airborne discharges of TCE and failing to submit a Title V air permit by the October 1996 

deadline (Ref. 7, p. 5). Mr. Mullins was fined, sentenced to home confinement followed by probation, 

and ordered to perform 100 hours of community service (Ref. 7, p. 5). MRP now holds a Clean Air Act 

Title V operating permit that was issued January 16, 2008 (Ref. 7, p. 5). In accordance with MRP’s Title 

V permit, TCE usage is now a facility-wide 12-month limit of 15.54 tons (Ref. 7, p. 5).

PREVIOUS INVESTIGATIONS

Ohio EPA has conducted several investigations at the MRP facility and surrounding area between 2008 

and 2013 (Ref. 7, p. 5). Site assessment work conducted during the Valley Pike VOCs investigation in 

July 2013 identified migration of contaminated ground water that may present potential hazards to nearby 

residences and businesses from subsurface migration of solvent vapors into indoor air (Ref. 7, p. 1). 

Chemicals of concern included PCE and TCE (Ref. 7, p. 1). As a result, in December 2013, EPA initiated 

a time-critical removal action, known as the Valley Pike VOC Site (Ref. 7, p. 1), which encompassed the 

larger Valley Pike area, including the Valley Pike VOCs site as scored in this HRS documentation record. 

The removal action included sub-slab vapor and indoor air sampling of residences and installing 

mitigation systems at residences exceeding the ATSDR/ODH screening levels for PCE and TCE (Ref. 7, 

p. 1; 15, pp. 6, 7). In March 2014, additional ground water samples were collected beyond the initial 

investigation area (Ref. 52, p. 11). March 2014 ground water sampling results indicated PCE and TCE 

contamination that led to an expansion to the southwest of the residential area of investigation for vapor 

intrusion sampling (see Figure 5 of this HRS documentation record) (Ref. 52, p. 11). As of January 20, 

2015, 83 of approximately 300 residences sampled exceeded the ODH screening levels for PCE and/or 

TCE (Ref. 7, p. 1). As of April 2015, vapor intrusion mitigation systems have been installed at 75 

residences (Ref. 7, p. 1). 

Of the various locations that have been sampled in the Valley Pike VOC Site area, the highest 

concentrations of PCE and TCE in soil, ground water, and sub-slab vapor have been detected in samples 

collected at the MRP facility, adjacent to and immediately southwest and downgradient of the MRP vapor 

degreaser and dry/injection well areas (Ref. 7, p. 2). 

The ODH has determined that a completed exposure pathway exists through vapor intrusion from ground 

water to indoor air in the residential neighborhood downgradient of the MRP facility (Ref. 7, p. 3). In 

November 2014, U.S. EPA expanded the area of investigation for the removal action to include additional 

residential areas. Vapor intrusion sampling and mitigation activities are ongoing (Ref. 7, p. 3). 

As of January 2016, EPA and MRP signed an Administrative Settlement Agreement and Order on 

Consent for Removal Action (Settlement Agreement) (Ref. 51, pp. 28, 29, 30). Though not included as 

part of the site for HRS scoring purposes, the Settlement Agreement identified the Valley Pike VOC Site 

(see Figure 5 of this HRS documentation record) as containing a residential area with documented vapor 

intrusion from a PCE- and TCE-contaminated, shallow ground water plume (Ref. 51, p. 4). The 

residential area includes about 500 residences and is located approximately 900 feet southwest of MRP 

(Ref. 51, p. 4). The Settlement Agreement identifies the MRP facility as the source of the ground water 

plume (Ref. 51, p. 4). 
16 Source Characterization

2.2 SOURCE CHARACTERIZATION

2.2.1 SOURCE IDENTIFICATION

Number of source: 1 

Name of source: Dry/Injection Well DW-2 

Source Type: Other 

Description and Location of Source (see Figure 3 of this HRS documentation record): 

MRP used four production wells to pump ground water for use as non-contact cooling water for its rubber 

mixing mills and vapor degreasers (Refs. 8, pp. 2, 7, 467 to 469; 14, p. 4). The deep production well (130 

feet deep), located in the east-central portion of the MRP property, produced about 250 to 300 gallons of 

water per minute for 8 hours a day (Refs. 7, p. 3; 8, p. 2; 33). Based on the boring log, the deep 

production well is 130 feet deep but is cased to 120 feet bgs (Ref. 8, p. 467). Prior to 2012, non-contact 

cooling water from MRP’s rubber mills and degreasing tanks associated with the manufacturing process 

previously discharged into a series of “dry” wells on the property (Refs. 8, p. 24; 14, p. 4; 15, p. 42; 17, p. 

12; 40, pp. 1, 2). Seven dry wells, including Source No. 1, reportedly were used to manage non-contact 

cooling water, storm drainage, and boiler blowdown water (Refs. 7, pp. 3, 4; 15, pp. 4, 41; 17, p. 12). 

Source No. 1 is dry well 2 (DW-2) located in the northwestern portion of the MRP property (Ref. 15, pp. 

4, 41). DW-2 is the only dry well that has been sampled during previous investigations conducted at 

MRP (Refs. 8, pp. 11, 19, 98; 16, p. 1; 17, pp. 5, 12, 13, 37). Although MRP refers to DW-2 as a “dry 

well,” a well log for DW-2 indicates that this well extends to 50 feet bgs, through an upper clay layer and 

into an underlying water bearing gravel layer (within the shallow sand and gravel zone of the GMBVAS) 

(Refs. 14, p. 48; 15, p. 42; 17, p. 128; 33). Therefore, DW-2 discharged water directly into an underlying 

aquifer (Refs. 15, p. 42; 17, p. 128; 33). This type of well (commonly referred to as an injection well) 

differs in construction from other wells referred to as “dry” wells in the area that are used solely for storm 

water management and that collect and allow surface drainage to infiltrate directly into the shallow 

subsurface through the vadose zone (Refs. 15, p. 4; 38). MRP’s DW-2 is considered a Class V injection 

well under the Ohio UIC Program (Refs. 14, p. 4; 15, p. 4; 38). A permit was not issued, but DW-2 along 

with the other dry wells at MRP were registered with Ohio EPA (Ref. 15, p. 4). DW-2 and other MRP 

dry wells will be referred to as “dry/injection wells” in this HRS documentation record. 

From about 1994 to 2012, MRP disposed of non-contact cooling water (withdrawn from the deep zone of 

the sand and gravel aquifer using the 130-foot-deep production well) into DW-2, a 50-foot dry/injection 

well that discharged into the shallow sand and gravel zone of the GMBVAS (Refs. 7, p. 3; 14, p. 3; 26, p. 

2-1). During Ohio EPA and U.S. EPA investigations, ground water samples collected from the 130-footdeep production well contained TCE (up to 6.18 micrograms per liter [μg/L]) and PCE (up to 156 μg/L) 

(Refs. 17, pp. 103, 122, 126; 33). In 2010 and 2011, MRP collected ground water samples from DW-2; 

PCE (up to 105 μg/L) and TCE (up to 2.72 μg/L) were detected in the samples (Refs. 14, pp. 4, 14, 24, 

26, 31, 35, 40, 47, 48, 53). Therefore, DW-2 is evaluated as a source into which PCE- and TCEcontaminated ground water was discharged (Refs. 8, pp. 150, 153; 14, pp. 26, 53; 17, pp. 29, 30).

As a result of this contamination, in February 2012, Ohio EPA, Division of Drinking and Ground Waters 

requested that MRP collect and provide analysis of the non-contact cooling water immediately prior to the 

non-contact cooling water entering the dry/injection wells (Refs. 41, pp. 1, 2; 43, p. 1). In May 2012, 

MRP notified Ohio EPA that MRP planned to install a closed loop system that will eliminate the need for 

using the dry wells for non-contact cooling water (Ref. 44). 
17 Source Characterization

Subsequently in October 2012, MRP vice president indicated in a letter to Ohio EPA that MRP was aware 

that they were drawing cooling water from a well that contained PCE- and TCE-contaminated ground 

water (Ref. 40, p. 1). In the same letter, MRP stated that the operational processes reduced the PCE and 

TCE concentrations in the ground water prior to MRP discharging the process water to the dry/injection 

wells but that Ohio EPA has demanded that MRP “cease and desist” this long standing operational 

practice (Ref. 40, pp. 1, 2). MRP also stated that in order to be in regulatory compliance as directed by 

Ohio EPA, they had removed one of the dry/injection wells and the remaining dry/injection wells no 

longer received cooling water discharge and only manage storm water (Ref. 40, pp. 2, 3, 4). Also, MRP 

confirmed the installation of a chiller unit and underground holding tanks for non-contact cooling water 

for its closed loop system (Ref. 40, p. 2). Because MRP abandoned the dry/injection wells and installed a 

chiller system, Ohio EPA determined that sampling and analysis of the non-contact cooling water 

entering the dry/injection wells, which included DW-2, was no longer necessary (Ref. 43, p. 1). 

Currently, the active production well, which previously supplied the contaminated PCE- and TCEcontaminated water, is used infrequently to “top off” the closed loop system (Ref. 7, p. 3). Two 

additional deep production wells are on standby (Ref. 7, p. 3). 
18 Source Characterization

2.2.2 HAZARDOUS SUBSTANCES ASSOCIATED WITH THE SOURCE

Table 1 lists ground water samples collected from Source No. 1, DW-2, that contained PCE and TCE 

(Refs. 8, pp. 150, 153; 14, pp. 26, 53; 17, pp. 29, 30). Ground water sample E2699/E2699DL was 

collected during the Ohio EPA 2010 Site Inspection (SI) and ground water sample E5LB2/E5LB2DL was 

collected during the Ohio EPA 2011 Expanded Site Inspection (ESI) (Refs. 8, pp. 150 to 153, 212; 14, pp. 

31, 62; 17, pp. 29, 30, 37). Ground water samples DTK0125-07 and DUJ0707-01 were collected by MRP 

in 2010 and 2011, respectively (Ref. 14, pp. 31, 33 to 35, 40, 51, 62). 

Chain-of-custody records for samples presented in Table 1 are included in References 8, p. 212; 14, pp. 

31, 62; and 17, p. 37. The locations of ground water samples listed in Table 1 are provided in Figure 3 of 

this HRS documentation record (Refs. 8, p. 19; 14, p. 40; 17, p. 12, 13). 

TABLE 1: Source No. 1 Samples 

Well Screen 

Sample ID Aquifer 

Interval

(feet msl)

Date 

Sampled Location References

SI—November 2010

E2699/E2699DL GMBVAS 745 to 732 11/2/2010 Sample GW-8 

collected from DW-2

3; 16, p. 1; 

17, pp. 12, 

13, 17, 37, 

128; 33

DTK0125-07 GMBVAS 745 to 732 11/2/2010

Split sample from 

GW-8 collected from 

DW-2

14, pp. 25, 

26, 31, 33 to 

35, 40, 48; 

19; 33

MRP Sampling Event—October 2011

DUJ0707-01 GMBVAS 745 to 732 10/18/2011 UIC DRY WELL 

Collected from DW-2

14, pp. 4, 51, 

62; 19; 33

ESI—December 2011

E5LB2/E5LB2DL GMBVAS 745 to 732 12/13/2011 Dry Well

(DW-2) 

8, pp. 11, 19, 

98, 144, 212, 

469; 15, p. 

23; 17, p. 12; 

33

Notes: 

DL Diluted sample 

DW Dry well 

GMBVAS Great Miami Buried Valley Aquifer System 

ID Identification number 

msl Mean sea level 

UIC Underground Injection Control 
19 Source Characterization

Table 2 presents analytical results of ground water samples collected from Source No. 1 (Refs. 8, pp. 150, 

153; 14, pp. 26, 53; 17, pp. 29, 30). Ground water sample E2699/E2699DL was collected during the 

Ohio EPA November 2010 SI and was analyzed for VOCs by ALS Laboratory Group in accordance with 

U.S. EPA CLP SOW SOM01.2 (6/2007) (Ref. 17, pp. 17, 18). The analytical results were reviewed in 

accordance with the National Functional Guidelines (NFG) for SOM01.2 and the SOP for ESAT 

5/TechLaw Validation of Contract Laboratory Program Organic Data (Version 2.4) (Ref. 17, pp. 17, 18). 

The data validation effort shows the overall data quality to be acceptable (Ref. 17, pp. 18 to 24). The 

analytical data sheets are provided in Appendix B of Reference 17. The sample specific contract required 

quantitation limits (CRQL) are adjusted for sample volume and dilution and are provided in Reference 45, 

p. 2. 

Ground water sample E5LB2/E5LB2DL was collected during the Ohio EPA December 2011 ESI and was 

analyzed for VOCs by Mitkem Laboratories in accordance with U.S. EPA CLP SOW SOM01.2 (6/2007) 

(Ref. 8, p. 144, 145). The analytical results were reviewed in accordance with the National Functional 

Guidelines (NFG) for SOM01.2 and the SOP for ESAT 5/TechLaw Validation of Contract Laboratory 

Program Organic Data (Version 2.6) (Ref. 8, p. 145). The data validation effort shows the overall data 

quality to be acceptable (Ref. 8, pp. 144 to 149). The analytical data sheets are provided in Appendix D 

of Reference 8. The adjusted sample-specific CRQLs are adjusted for sample volume and dilution and 

are provided in Reference 45, p. 2. 

Samples DTK0125-07 and DUJ0707-01 were collected by MRP in November 2010 and October 2011, 

respectively (Ref. 14, pp. 31, 62). The samples were analyzed by Test America (Ref. 14, pp. 14, 49). 

Sample DTK0125-07 was analyzed for VOCs and sample DUJ0701-01 was analyzed for PCE and TCE

using EPA Method SW 8260B (Ref. 14, pp. 14, 26, 53). The reporting limits are listed on pages 26 and 

53 of the analytical data sheets in Reference 14. The reporting limits are adjusted for sample 

characteristics that may affect quantitation, such as dilutions (Ref. 47, p. 1). The reporting limits are 

equivalent to sampling quantitation limits (SQLs) as defined in Section 1.1, Definitions of the HRS (Refs. 

1, p. 51586; 47, p. 1). 
20 Source Characterization

TABLE 2: Source No. 1 Concentrations

Sample ID/

Location

Hazardous 

Substance

Concentration

(μg/L)

Adjusted 

CRQL/SQL

(μg/L) References

SI—November 2010

E2699DL

(GW-8 from DW-2) PCE 82 5.0

17, pp. 23, 30, 82; 

45, pp. 1, 2, 4, 6, 7; 

46, p. 2

E2699

(GW-8 from DW-2) TCE 2.2 0.5 17, pp. 29, 79; 45, pp. 2, 5; 46, p. 2

DTK0125-07

(GW-8 from DW-2)

PCE 89.5 1.0 14, p. 26; 47

TCE 2.72 1.0 14, p. 26; 47

October 2011

DUJ0707-01

(UIC DRY WELL/DW-2)

PCE 105 1.0 14, p. 53; 33; 47

ESI—December 2011

E5LB2DL/

Dry Well

(DW-2)

PCE 76 4.0

8, pp. 148, 152, 153, 

219, 237; 45, pp. 1, 

2, 4, 12, 13; 46, p. 2

E5LB2/

Dry Well

(DW-2)

TCE 1.4 0.5

8, pp. 150, 234; 45, 

pp. 1, 2, 4, 9, 13; 46, 

p. 2

Notes: 

μg/L Micrograms per liter 

CRQL Contract required quantitation limit 

DW Dry well 

EPA U.S. Environmental Protection Agency 

GW Ground water 

ID Identification 

PCE Tetrachloroethylene 

SQL Sample quantitation limit 

TCE Trichloroethylene
21 Source Characterization

2.2.3 HAZARDOUS SUBSTANCES AVAILABLE TO A PATHWAY

Samples collected from Source No. 1 contained PCE and TCE (see Table 2 of this HRS documentation 

record). Source No. 1 consists of an MRP dry/injection well into which contaminated non-contact 

cooling water was discharged (see Tables 1 and 2 and Figure 3 of this HRS documentation record). 

Analytical results for ground water samples collected from the GMBVAS underlying and in the vicinity 

of Source No. 1 indicate that a release of hazardous substances has occurred to the ground water 

migration pathway, as documented in Section 3.0 of this HRS documentation record. 

Based on the intended use of Source No. 1 as a dry/injection well, a liner would not be expected to be 

present. In addition, a well log for a “dry well” at MRP does not indicate that a liner was included as part 

of the installation (Refs. 14, p. 48; 15, p. 42). Additional logs for soil borings and monitoring wells 

installed in 2014, indicate a liner was not observed in the vicinity of Source No. 1 (Ref. 15, pp. 44 to 59). 

Therefore, a containment factor value of 10, as noted in Table 3 of this HRS documentation record, was 

assigned for the ground water migration pathway (Ref. 1, Section 3.1.2.1, Table 3-2).

List of Hazardous Substances

Tetrachloroethylene

Trichloroethylene

TABLE 3: Containment Factors for Source No. 1

Containment Description

Containment 

Factor Value References

Gas release to air NS NA

Particulate release to air NS NA

Release to ground water: No liner 10 1, Section 3.1.2.1, Table 3-2; 15, 

pp. 44 to 59

Release via overland migration and/or flood NS NA

Notes:

NA Not applicable

NS Not scored
22 Source Characterization

2.4.2.1 HAZARDOUS WASTE QUANTITY

Insufficient information exists to evaluate Hazardous Constituent Quantity. The hazardous waste quantity value 

is calculated using Tier C, Volume of contaminated non-contact cooling water (Ref. 1, pp. 51590, 51591). 

2.4.2.1.1 Hazardous Constituent Quantity – Tier A

The hazardous constituent quantity for Source No. 1 could not be adequately determined according to the HRS 

requirements; that is, the total mass of all CERCLA hazardous substances in the source and releases from the 

source is not known and cannot be estimated with reasonable confidence (Ref. 1, pp. 51590-51591 [Section 

2.4.2.1.1]). There are insufficient historical and current data (manifests, potentially responsible party [PRP] 

records, State records, permits, waste concentration data, etc.) available to adequately calculate the total or partial 

mass of all CERCLA hazardous substances in the source and the associated releases from the source. Therefore, 

there is insufficient information to evaluate the associated releases from the source to calculate the hazardous 

constituent quantity for Source No. 1 with reasonable confidence. Scoring proceeds to the evaluation of Tier B, 

Hazardous wastestream quantity (Ref. 1, p. 51591). 

Hazardous Constituent Quantity Assigned Value: NS 

Are the data complete for hazardous constituent quantity for this area? No 

2.4.2.1.2 Hazardous Wastestream Quantity – Tier B

The hazardous wastestream quantity for Source No. 1 could not be adequately determined according to the HRS 

requirements; that is, the mass of all hazardous wastestreams plus the mass of any CERCLA pollutants and 

contaminants in the source and releases from the source is not known and cannot be estimated with reasonable 

confidence (Ref. 1, p. 51591 [Section 2.4.2.1.2]). There are insufficient historical and current data (manifests, 

PRP records, State records, permits, waste concentration data, etc.) available to adequately calculate the total or 

partial mass of the wastestream plus the mass of all CERCLA pollutants and contaminants in the source and the 

associated releases from the source. Therefore, there is insufficient information to evaluate the associated releases 

from the source to calculate the hazardous wastestream quantity for Source No. 1 with reasonable confidence. 

Scoring proceeds to the evaluation of Tier C, Volume (Ref. 1, p. 51591). 

Hazardous Wastestream Quantity Assigned Value: NS 

Are the data complete for hazardous constituent quantity for this area? No 

2.4.2.1.3 Volume – Tier C

For the migration pathways, the source is assigned a value for volume using the appropriate Tier C equation from 

Table 2-5 (Ref. 1, p. 51591 [Section 2.4.2.1.3]). Due to a lack of available records, monitoring data and discharge 

information, the volume capacity of the dry/injection well is unknown, as is the quantity of contaminated process 

water that was discharged to Source No. 1. Therefore, the volume of Source No. 1 will be designated as unknown, 

but contaminated source samples are present, so the quantity is greater than zero. 

Volume Assigned Value: unknown, but >0

Are the data complete for volume quantity for this area? No 
23 Source Characterization

2.4.2.1.4 Area – Tier D

The area measure (Tier D) is not evaluated for source type “other” (Ref. 1, Table 2-5).

Area Assigned Value: 0

Are the data complete for area quantity for this area? No

2.4.2.1.5. Source Hazardous Waste Quantity Value

The source hazardous waste quantity value for Source No. 1 was evaluated based on volume, Tier C. However, 

insufficient data is available to determine the volume of PCE- and TCE-contaminated non-contact cooling water 

discharged to Source No. 1, DW-2. Therefore, the source hazardous waste quantity value for Source No. 1 is 

unknown, but greater than 0.

Source HWQ Value: unknown, but >0
24 Source Characterization

SUMMARY OF SOURCE DESCRIPTIONS

TABLE 4: Summary of Source Descriptions 

Containment Factor Value by Pathway

Source 

Source 

Hazardous Surface 

Hazardous Constituent Air Water 

Waste Quantity Ground Overland/ 

Source Quantity Complete? Water Flood Gas Particulate 

No.

1 

Value

>0

(Yes/No)

No

(Table 3-2) (Table 4-2) (Table 6-3) (Table 6-9)

10 NS NS NS

Notes: 

> Greater than

NS Not scored

Description of Other Possible On-Site Sources 

Contaminated Soil 

An area of PCE- and TCE-contaminated soil exists on the MRP property and extends into the adjacent property 

(Refs. 15, pp. 30, 95, 97, 99, 118, 126; 21, pp. 2, 3). During various investigations, Ohio EPA and U.S. EPA have 

collected subsurface soil and sub-slab soil-vapor samples at and in the vicinity of the MRP property (Refs. 7, p. 2; 

8, p. 1). Analytical results of the subsurface soil and sub-slab vapor samples indicate the presence of PCE and 

TCE at the MRP facility (Ref. 7, pp. 22, 23). 

Subsurface soil samples collected downgradient of the former degreaser and DW-2 (Source No. 1) contained PCE 

and TCE. PCE concentrations ranged from 0.014 milligrams per kilogram (mg/kg) to 2,040 mg/kg (Refs. 15, pp. 

30, 95, 99, 118, 126; 21, pp. 2, 3). More specifically, PCE was detected at the following concentrations in 

subsurface soil samples: at 0.043 mg/kg in a sample collected from MW-EPA-7, collected in the vicinity of the 

former degreaser at a depth of 15 to 17 feet bgs; at 0.032 mg/kg and 2,040 mg/kg in samples collected from MWEPA-8, collected on the western side of the MRP building and downgradient of Source No. 1 at depths of 13 to 15 

feet bgs and 24 to 26 feet bgs, respectively; and at 0.014 mg/kg in subsurface soil sample SB-MW-14-1820, 

collected downgradient of Source No. 1 at 18 to 20 feet bgs (Ref. 15, pp. 30, 95, 99, 118, 126; 21, pp. 2, 3). In 

addition, TCE was detected at the following concentrations in subsurface soil samples collected from MW-EPA-8 

as follows: at 2.6 mg/kg between 20 to 22 feet bgs and at 411 mg/kg between 24 to 26 feet bgs (Ref. 15, pp. 30, 

97, 99). Soil sampling locations are shown on Figure 4 of this HRS documentation record. 

During installation of a monitoring well at MW-EPA-8 located along the western property boundary of the MRP 

property, PID readings from field screening of soil cores were as high as 3,700,000 ppb at 25 feet bgs--the bottom 

foot of the glacial till layer (Ref. 15, pp. 10, 46, 47). No other PID readings were noted above 2,000 ppb at any 

location upgradient of the MRP property (Ref. 15, pp. 10, 48 to 55). 
25 Source Characterization

A large portion of the MRP property is covered with structures that prevent the collection of soil samples (Ref. 

15, p. 8). For this reason, sub-slab vapor samples were collected at six locations beneath the floor slabs in the 

MRP main building in September 2014 (Ref. 15, p. 8). Samples were collected by using a hammer drill to drill 

completely through the floor slab and extending several inches past the bottom of the slab (Ref. 15, p. 9). A 

permanent stainless steel sample port was installed so that the port would extend less than 1 inch beyond the 

bottom of the slab (Ref. 15, p. 9). Analysis of these sub-slab vapor samples revealed high levels of PCE and TCE 

(Ref. 7, p. 2). PCE was detected between 44.1 and 3,550,000 micrograms per cubic meter (μg/m3) and TCE 

between 104 and 44,400 μg/m3(Ref. 7, pp. 9, 10, 22). The highest detection of PCE was in a sub-slab sample 

collected near the degreaser (Ref. 7, p. 2). Information provided by MRP states that MRP has historically used

and currently uses TCE (Ref. 14, pp. 1, 3).

Based on the contamination detected in the soil samples collected from locations shown on Figure 3 of Reference 

15, an approximate contaminated soil source area of 2,500 square feet was identified between samples SB-MWEPA-7, SB-MW-EPA-8, and SB-MW-EPA-14 (Ref. 15, p. 25). However, it should be noted that the extent of 

soil contamination under the buildings is not known, therefore, the actual area of on-site soil contamination may 

be greater.

As discussed in the Attribution section, a Settlement Agreement between U.S. EPA and MRP was signed in 

January 2016 and identified the (larger) Valley Pike VOC Site containing a residential area with documented 

vapor intrusion of PCE- and TCE contamination. The Settlement Agreement includes provision for conducting 

vapor screening and mitigation and for design, installation and operation of a soil vapor extraction (SVE) system 

at the MRP facility (Ref 51, p. 7, 8).

No other possible on-site sources have been identified. 
26 GW-Likelihood of Release

3.0 GROUND WATER MIGRATION PATHWAY

3.0.1 GENERAL CONSIDERATIONS

Ground Water Migration Pathway Description

Regional Geology

The Valley Pike VOCs site is located in Riverside, Montgomery County, Ohio, and lies on the Till Plains 

Section of the Central Lowland physiographic province (Refs. 4; 22, p. 6). The topography of the Till 

Plains is the result of continental glaciation; bedrock features formed by preglacial drainage systems are 

buried under glacial deposits. The land surface is flat to gently rolling (Refs. 22, p. 6; 23, p. 2). The 

elevation at the MRP property is about 782 feet above mean sea level (msl) (Ref. 3) (see Figures 1 and 3 

of this HRS documentation record). Montgomery County is underlain in descending stratigraphic order 

by all or some of the following units: Quaternary glacial deposits and Ordovician sedimentary rocks (Ref. 

25, pp. 13, 14, 16, 17, 19). 

The glacial deposits consist of two generalized types, differentiated primarily by the principal grain size 

content: outwash, also known as valley train material, that was deposited by glacial meltwater and 

consists chiefly of gravel and sand size sediments; and till deposited directly by the glaciers as they 

advanced over the area and consists of clay-rich materials (Ref. 26, p. 2-1). Six units compose the glacial 

deposits and include, in descending order: top soil/surficial clay, shallow sand and gravel, shallow 

subsurface till, intermediate sand and gravel, intermediate subsurface till, and deep sand and gravel (Ref. 

26, p. 2-2). These units are not consistently observed in all locations within the region because of the 

complex nature of the geologic system (Ref. 26, p. 2-2). These glacial deposits range in thickness from 

about 150 to 300 feet (Ref. 22, p. 6). A generalized description of the glacial deposits, in descending 

order, is presented below.

Top soil/surficial clay – Consists of silt or clay and is discontinuous. Where present, it is generally 10 

feet thick with an approximate range of thickness of between 5 and 40 feet (Ref. 26, p. 2-2). 

Shallow sand and gravel – Consists of sand, gravel, or both and is horizontally continuous with a general 

thickness of 60 feet and a range of thickness of between 10 and 100 feet (Ref. 26, p. 2-2).

Shallow subsurface till – Primarily consists of silt or clay and is horizontally discontinuous. Where 

present, the unit is generally 20 feet thick with an approximate range of thickness of between 0 and 40 

feet (Ref. 26, p. 2-2).

Intermediate sand and gravel –Primarily consists of sand, gravel or both, is horizontally discontinuous, 

and varies in thickness with lenses of silt and clay deposits. Where present, the unit is generally 50 feet 

thick with a range of thickness of between 0 and 80 feet (Ref. 26, p. 2-2). 

Intermediate subsurface till – Consists primarily of silt or clay, is horizontally discontinuous, and varies 

in thickness with lenses of sand and gravel deposits. Where present, the unit is generally 30 feet thick 

with a range of thickness of between 0 and 50 feet (Ref. 26, p. 2-2).

Deep sand and gravel – Consists primarily of sand, gravel, or both, is horizontally discontinuous, and 

directly overlies basal clays or bedrock. The general thickness is 70 feet with a range of thickness of 

between 0 and 140 feet (Ref. 26, p. 2-2).

Underlying the glacial deposits are Ordovician-age sedimentary rocks containing limestone and shale 

(Refs. 24, p. 4; 25, p. 16). These rocks were derived from marine sediments that formed thick beds of 

shale interbedded with thin beds of coarse fossiliferous limestone (Ref. 25, p. 16). The thin limestone 

beds constitute approximately 20 percent of the sequence and are most common in the uppermost part of 

the Ordovician sequence (Ref. 25, p. 16). These rocks are more than 1,000 feet thick (Ref. 23, p. 5). 
27 GW-Likelihood of Release

Regional Aquifer Description

Overview Narrative – Aquifers in the Dayton area are considered to be part of the GMBVAS (Ref. 26, p. 

2-1). The GMBVAS is a buried valley system that follows the general trend of the present-day Great 

Miami, Mad, Stillwater, and Wolf Creek Rivers and is the result of valleys cut into the bedrock (shale and 

limestone) by river and glacial erosion followed by filling with glacial deposits (clay, silt, sand, and 

gravel) (Ref. 26, p. 2-1). This aquifer system supplies the greatest quantity of water in the Dayton area 

and southwestern Ohio and has been designated by EPA as a sole-source aquifer (Refs. 25, pp. 1, 4, 34; 

26, p. 2-1). 

Great Miami Buried Valley Aquifer System – The GMBVAS consists of unconsolidated sand and gravel 

units that are partially- to fully-saturated with ground water. The hydrogeologic system is complex 

because of variations in thickness and extent (Ref. 26, p. 2-3). The deposits range in thickness from 0 to 

400 feet; however, typical thickness is 150 to 200 feet (Ref. 25, p. 34). Based on well logs in the vicinity 

of the site, confining layers locally separate the units of the aquifer but are not continuous or consistently 

present (Ref. 15, pp. 15, 23, 25 to 28, 45 to 59). 

Ground water is encountered at about 15 feet bgs and elevations range from 840 feet above msl in the 

northeastern and southeastern extent of the region to 717 feet above msl in the southwestern extent of the 

region (Refs. 22, p. 7; 26, p. 2-3). The aquifer is confined to semi-confined by the overlying subsurface 

clay and silt unit (Refs. 15, pp. 23, 25 to 27; 26, p. 2-3). 

Underlying the GMBVAS is the bedrock aquifer (composed of Richmond Shales of the late Ordovician 

Period), which yields significantly less water than the overlying sand and gravel aquifer system (Refs. 26, 

p. 2-3; 31, p. 18). The Ordovician shales are virtually impermeable. The limestone layers are dense and

not very porous, and the fine-grained shales are generally less permeable (Ref. 31, p. 27). The bedrock

aquifer is not evaluated in this HRS documentation record.

Ground water within the GMBVAS primarily is recharged through percolation from precipitation, area 

streams, and the Great Miami River. The river recharges the GMBVAS during high river flow periods, 

which generally occurs from November through April (Ref. 27). 

The hydrogeology of the buried-valley aquifer is highly heterogeneous, with extreme lithologic variation 

over short distances with depth. Clay and silt-rich zones are interbedded with sand and gravel deposits 

but are laterally discontinuous (Refs. 22, pp. 5, 8; 29). 

Site Geology/Hydrogeology 

During the 2014 EPA Contaminant Source Area Investigation, eight borings were advanced on and 

adjacent to the MRP property (Ref. 15, pp. 9, 25). Based on the borings, subsurface materials were found 

to consist of varying thicknesses of fill materials and overlying glacial-derived, unconsolidated deposits. 

The glacial-derived materials consisted of mixed and interbedded sand, gravel, silt, and clay (Ref. 15, p. 

15). Generally, sands and gravels are the predominant deposits. A layer of dense glacial till (blue clay or 

gray silty clay with varying amounts of fine to coarse gravel and cobbles) was encountered in most 

borings, separating the overlying silt, sand, and gravel from coarser sands and gravels below (Ref. 15, pp. 

15, 42 to 59). Well borings installed on the MRP property, as well as within a 2-mile radius of Source 

No. 1, show that clay and silt-rich zones are not continuous (Refs. 8, pp. 25, 467 to 503; 15, pp. 15, 23, 25 

to 28, 42 to 59). Where present, the till layer was encountered at depths ranging from 15 to 35 feet bgs 

(767 to 747 feet above msl) (Ref. 15, pp. 15, 42 to 59). The thickness of the till appears to decrease from 

north to south in the vicinity of the MRP property and the Rockcastle property (located adjacent and 

northeast (upgradient) of the MRP property), and is absent on the south side of Valley Pike in boring 

MW-EPA-9 (Ref. 15, pp. 15, 48, 49). Boring MW-EPA-9 is located about 560 feet south of Source No. 1 

(Ref. 15, p. 25). Below the till, fine to coarse sand and gravel were encountered at all boring locations 

(Ref. 15, pp. 42 to 59). 
28 GW-Likelihood of Release

The boring log for the active production well (ODNR Well Log Number: 693135) installed in 1989 about 

180 feet southeast of Source No. 1 (approximate elevation of 782 feet above msl; see Figures 1 and 3 of 

this HRS documentation record), indicates that the property is underlain by: topsoil from 0 to 3 feet bgs 

(782 to 779 feet above msl); dry gravel from 3 to 32 feet bgs (779 to 750 feet above msl); sand and gravel 

from 32 to 51 feet bgs (750 to 731 feet above msl); blue clay from 51 to 116 feet bgs (731 to 666 feet 

above msl); and sand and gravel from 116 to 130 feet bgs (666 to 652 feet above msl) (Refs. 8, p. 467; 19; 

33, p. 2). Ground water was encountered at 51 feet bgs (731 feet above msl) and 130 feet bgs (652 feet 

above msl) (Refs. 8, p. 467; 19; 33, p. 2). According to the boring log, the well is screened within the 

sand and gravel aquifer between 116 and 130 feet bgs (666 to 652 feet above msl) (Refs. 8, p. 467; 17, p. 

13; 19). Based on the boring log for the active production well (ODNR Well Log Number: 693135), 

ground water in the site area is divided into two zones, shallow and deep, separated by an approximately 

65-foot layer of blue clay (Refs. 8, pp. 19, 467; 19 ). 

The boring log for the old production well (ODNR Well Log Number: 388390) installed in 1969 about 

200 feet southeast of Source No. 1 (approximate elevation of 782 feet above msl (see Figures 1 and 3 of 

this HRS documentation record), shows the presence of a blue clay layer between 47 and 111 feet bgs 

(735 to 671 feet above msl) (Refs. 8, pp. 5, 468; 17, p. 13; 19; 33, p. 2). According to the boring log, the 

well is screened within the gravel aquifer at 36 to 47 feet bgs (746 to 735 feet above msl) (Refs. 8, pp. 5, 

468; 19; 33, p. 2). 

The boring log for the Source No. 1 (DW-2, ODNR Well Log Number 438258) installed in 1972 in the 

northwestern portion of the MRP (approximate elevation of 782 feet above msl), shows the presence of a

blue clay layer between 25 and 37 feet bgs (757 and 745 feet above msl). The well is screened within the 

gravel aquifer at 37 to 50 feet bgs (745 to 732 feet above msl) (Refs. 8, p. 469; 15, p. 23; 17, p. 13; 19; 33, 

p. 4). 

A boring log (MR-102D) for a well, installed in 1986, about 1.6 miles west southwest of the MRP 

property (see Reference 28 for approximate location) shows coarse sand and fill from 0 to 10 feet bgs 

(754.4 to 744.4 feet above msl), gray sandy clay from 10 to 17 feet bgs (744. to 737.4 feet above msl), 

well rounded fine to coarse sand from 17 to 42 feet bgs (737.4 to 712.4 feet above msl), medium gravel 

and coarse sand from 42 to 56 feet bgs (712.4 to 698.4 feet above msl), silty sand with lenses of gravel 

from 56 to 91 feet bgs (698.4 to 663.4 feet above msl), medium to coarse sand and gravel from 91 to 111 

feet bgs (663.4 to 643.4 feet above msl), gray sandy clay from 111 to 115 feet bgs (643.4 to 639.4 feet 

above msl), medium to coarse sand and gravel with large boulders from 115 to 154 feet bgs (639.4 to 

600.4 feet above msl), and large boulders and cobbles with occasional thin layers of clay from 154 to 162 

feet bgs (600.4 to 592.4 feet above msl) (Refs. 8, pp. 491 to 495; 19; 28). This well is screened between 

124 and 146 feet bgs (628.4 to 608.4 feet above msl) (Refs. 8, pp. 491 to 495; 19). 

These borings show that the unconsolidated glacial deposits vary greatly in thickness and extent across 

short lateral distances. The absence of a clay layer that is present in the MRP property borings shows that 

this clay layer is not continuous throughout a 2-mile radius of Source No. 1. This great lithologic 

variation also can be seen in a boring log (MR-103D) from a well installed about 0.95 mile southwest of 

Source No. 1 (see Reference 28 for approximate location) (Refs. 8, pp. 484 to 488; 28). This boring 

shows the presence of light gray clay with sand and gravel from 42 to 66 feet bgs (721.8 to 697.8 feet 

above msl) and 68 to 98 feet bgs (697.8 to 665.8 feet above msl) (Refs. 8, pp. 484 to 488; 19). 

Saturated material is generally first encountered at depths ranging from approximately 24 to 30 feet bgs 

(758 to 752 feet above msl) (Refs. 15, pp. 16, 42 to 59; 19). Typically, saturated material was not present 

above the till; however, minor amounts of moisture indicative of a low-yielding seasonal or “perched” 

zone were encountered in some borings (Ref. 15, pp. 10, 46, 47, 52, 53, 58, and 59). At other locations, 

saturation was generally encountered immediately below the dense till in coarse sands and gravels (Ref. 

15, pp. 16, 44, 45, 48 to 51, and 54 to 57). Ground water levels in completed monitoring wells in the 

Valley Pike VOCs site area ranged from 18.48 feet bgs (763.79 feet above msl) to 25.61 feet bgs (758.71 

feet above msl) (Refs. 15, p. 35; 19). The presence of ground water above the till is sporadic and 

associated with localized conditions. The till was not observed at some boring locations and varied in 
29 GW-Likelihood of Release

thickness where encountered (Ref. 15, p. 16). 

During the 2014 EPA Contaminant Source Area Investigation, ground water elevation data was collected 

from 16 wells in the Valley Pike VOCs site vicinity (Ref. 15, pp. 16, 35). Based on the ground water 

elevation data, ground water flow in the site vicinity is southwestward and runs approximately parallel to 

Valley Pike (Ref. 15, pp. 16, 35). 

Aquifer Interconnectivity and Discontinuity 

The GMBVAS is a sole-source aquifer system and thus the most important aquifer in southwest Ohio, 

which was formed by glacial erosion followed by filling with glacial deposits (clay, silt, sand, and gravel) 

(Refs. 26, p. 2-1; 30, p. 1). The hydrogeology of the aquifer is highly heterogeneous, with extreme 

lithologic variations over short distances and with depth (Ref. 22, pp. 5, 8). Clay and silt-rich zones are 

interbedded with sand and gravel deposits but are not laterally continuous within a 2-mile radius of 

Source No. 1 (Ref. 22, pp. 5, 8). Well borings installed on the MRP property as well as within a 2-mile 

radius of Source No. 1 show that the clay and silt-rich zones are not continuous (Refs. 8, pp. 25, 467 to 

503; 15, pp. 15, 23, 25 to 28, 42 to 59). Therefore, the GMBVAS underlying the MRP facility is a single 

interconnected aquifer within a 2-mile radius of Source No. 1 at MRP. The GMBVAS is continuous 

within a 4-mile radius of Source No. 1 at the MRP property (Refs. 22, p. 5; 29). 

SUMMARY OF AQUIFERS BEING EVALUATED

TABLE 5: Summary of Aquifers Being Evaluated

Aquifer Name

Is Aquifer 

Interconnected with 

Upper Aquifer within 2 

Miles? (Yes/No/NA)

Is Aquifer 

Continuous within 

4-mile TDL?

(Yes/No)

Is Aquifer 

Karst? 

(Yes/No) References

Great Miami 

Buried Valley 

Aquifer System 

(sole-source 

aquifer)

NA Yes No

1, Section 3.0.1.1; 

8, p. 4; see Section 

3.1.1 of this HRS 

documentation 

record

Notes: 

NA Not applicable 

TDL Target distance limit
30 GW-Likelihood of Release

3.1 LIKELIHOOD OF RELEASE

3.1.1 OBSERVED RELEASE

Aquifer Being Evaluated: Great Miami Buried Valley Aquifer System 

Hazardous Substances in Release: PCE and TCE 

Direct Observation 

Prior to 2012, MRP used production wells as a water supply for non-contact cooling water for the 

facility’s degreasers (Refs. 17, pp. 2, 12; 14, p. 4). After non-contact cooling water had circulated 

through the MRP vapor degreasers, MRP pumped the non-contact cooling water into DW-2 and other 

dry/injection wells on the property (Refs. 14, p. 4; 17, pp. 2, 12, 128). A well log from MRP dry/injection 

well DW-2 installed in 1972 was completed at 50 feet bgs (732 feet above msl) in a shallow sand and 

gravel zone of the GMBVAS (Refs. 17, p. 128; 19; 26, p. 2-1; 33). The water level in this dry/injection 

well was at 50 feet bgs (732 feet above msl) (Refs. 17, p. 128; 19). 

The Ohio EPA UIC program describes dry/injection wells (class V wells) as being completed in the 

vadose (unsaturated) zone of the subsurface and are used for stormwater management (Ref. 38). 

However, the well log for Source No. 1, located on the north side of the facility building, indicates that 

this dry/injection well was completed at about 50 feet bgs and is completed within a shallow sand and 

gravel zone of the aquifer (Refs. 17, p. 128; 8, pp. 24, 469). 

During the Ohio EPA November 2010 SI and December 2011 ESI, ground water samples collected from 

the MRP active production well contained PCE and TCE (Refs. 8, pp. 11, 164, 167, 214; 17, pp. 4, 5, 12, 

13, 100, 103; 33). Analytical results for a sample collected from Source No. 1 (DW-2) contained PCE 

and TCE (Refs. 17, pp. 5, 12, 13, 29, 30, 37, 103, 128; 33). In 2012, MRP indicated that PCE- and TCEcontaminated ground water pumped from the production well was used for non-contact cooling water. 

After passing through the vapor degreasers, the non-contact cooling water was then discharged into 

Source No. 1 (DW-2) and other dry/injection wells on the property (Ref. 14, p. 4). The dry/injection 

wells were employed before a closed loop system was installed at MRP (Ref. 14, p. 4). The PCE and 

TCE detected in DW-2, which was used for non-contact cooling water, and is screened in a shallow sand 

and gravel zone of the GMBVAS represents an observed release by direct observation in accordance with 

the HRS, Section 3.1.1 (Refs. 1, p. 51595; 14, pp. 1, 4). Table 6 below provides the depth to water in 

Source No. 1 (DW-2) and the concentrations of PCE and TCE detected during the Ohio EPA November 

2010 SI. 

TABLE 6: Observed Release by Direct Observation

Well 

Description Sample ID

Date 

Sampled

Well 

Screen 

Interval

(feet msl)

Hazardous 

Substance

Hazardous 

Substance 

Concentration

(μg/L)

Adjusted 

CRQL/SQL

(μg/L) References

Dry Well

GW-8 (DW-2)

E2699DL

11/2/2010 745 to 

732

PCE 82 5.0 16, p. 1; 17, pp. 

5, 12, 13, 29, 

30, 37, 128; 33; 

45, pp. 2 to 7 

E2699 TCE 2.2 0.5

Notes: 

CRQL Contract required quantitation limit 

DW Dry well 

GW Ground water 

ID Identification 

msl Mean sea level 
31 GW-Likelihood of Release

PCE Tetrachloroethylene 

SQL Sample quantitation limit 

TCE Trichloroethylene

Chemical Analysis 

An observed release by chemical analysis is established by showing that the hazardous substances in 

release samples are significantly greater in concentration than background level and by documenting that 

at least part of the significant increase is attributable to a release from the site being evaluated. The 

significant increase can be documented in one of two ways for HRS purposes. If the background 

concentration is not detected (or is less than the SQL), an observed release is established when the sample 

measurement equals or exceeds the appropriate SQL. If the background sample concentration equals or 

exceeds the SQL, an observed release is established when the sample measurement is 3 times or more 

above the background concentration and above the appropriate SQL (Ref. 1, p. 51589 [Table 2-3]). An 

observed release of PCE and TCE is documented in the following sections by comparing the 

concentrations of the hazardous substances in similar background and contaminated ground water 

samples (see Tables 9, 10, 11, and 12 in this section, Section 3.1.1, of this HRS documentation record) 

and by attributing the increase to the site. During the EPA October 2014 sampling event, background 

ground water samples collected from permanent monitoring wells MW-5, MW-6, MW-EPA-9, MWEPA-11, MW-EPA-12, and MW-EPA-13, located north, northeast, east, and southeast (upgradient and 

sidegradient) of Source No. 1, did not exhibit detectable concentrations of PCE and TCE (Refs. 15, pp. 

32, 152, 165, 167, 169, 171, 199; 21, pp. 5, 6, 8). Contaminated ground water samples collected from 

permanent monitoring wells MW-EPA-8 and MW-EPA-14, located downgradient of Source No. 1, have 

been found to contain PCE and TCE significantly above background levels (Refs. 15, pp. 32, 184, 201; 

21, pp. 7, 8). 

2014 EPA Sampling Event 

Background Samples 

To establish background levels, ground water samples collected during the EPA October 2014 sampling 

event were evaluated (from permanent monitoring wells MW-5, MW-6, MW-EPA-9, MW-EPA-11, MWEPA-12, and MW-EPA-13 installed north, northeast, east, and southeast (upgradient and sidegradient) of 

Source No. 1 (Ref. 15, p. 32). Ground water samples collected from these wells did not exhibit detectable 

concentrations of PCE (Ref. 15, pp. 152, 165, 167, 169, 171, 199). These permanent monitoring wells 

were selected to establish background levels and to encapsulate the PCE ground water contamination 

downgradient of Source No. 1 (Ref. 15, p. 32) (see Figures 3 and 4 of this HRS documentation record). 

The background wells are installed within a sand and gravel zone of the GMBVAS aquifer, are screened 

between 754.04 to 732.03 feet above msl (Refs. 15, pp. 35, 48, 49, 52 to 57; 18, pp. 179, 183, 206, 207, 

211, 212; 21, pp. 5, 6, 8) and will be compared with contaminated permanent monitoring well samples 

collected from the sand and gravel unit of the GMBVAS at similar screened intervals (751.8 to 741.57 

feet above msl) (Refs. 15, pp. 42, 46, 47, 58, 59; 33) (see Tables 7 and 8 of this HRS documentation 

record). 

The background samples were collected in accordance with the EPA-approved field sampling and 

analysis plan (SAP) dated September 2014 (Ref. 15, p. 8). The locations of the background ground water 

samples are contained in Reference 15, pp. 25, 32 (see Figure 4 of this HRS documentation record). Well 

construction diagrams are provided in Appendix B of Reference 15. Chain-of-custody forms (which 

provide the sample identification numbers and date and time of sample collection) are provided in 

Reference 21, pages 5, 6, 8. 

The background monitoring well samples and contaminated monitoring well samples were collected from 

permanent monitoring wells that withdraw water from the sand and gravel unit of the GMBVAS, at 

similar screened intervals, during the same sampling event, and in accordance with the same sampling 
32 GW-Likelihood of Release

procedures (Ref. 15, pp. 8, 10, 11, 12, 42, 48, 49, 52 to 57) (see Tables 7 and 8 of this HRS 

documentation record). 

TABLE 7: Background Ground Water Samples – October 2014

Sample ID

GMBVAS

Zone

Top of Casing 

Elevation 

(feet msl)

Well Screen 

Interval

(feet msl) Date Sampled Location References

GW-MW-5-

101414 Shallow 780.66 748.74 to 

743.74 10/14/2014 MW-5

9; 18, pp. 

179, 183, 

206, 207; 

21, p. 6

GW-MW-6-

101414 Shallow 779.48 747.98 to 

742.98 10/14/2014 MW-6

9; 18, pp. 

179, 183, 

211, 212; 

21, p. 6

GW-MW-9-

101614 Shallow 781.5 751.5 to 

741.5 10/16/2014 MW-EPA-9

9; 15, pp. 

48, 49; 21, 

p. 8

GW-MW-11-

101314 Shallow 783.04 750.72 to 740.72 10/13/2014 MW-EPA11

9; 15, pp. 

52, 53; 21, 

p. 5

GW-MW-12-

101414 Shallow 782.22 751.12 to 741.12 10/14/2014 MW-EPA12

9; 15, pp. 

54, 55; 21, 

p. 6

GW-MW-13-

101414 Shallow 780.03 742.03 to 732.03 10/14/2014 MW-EPA13

9; 15, pp. 

56, 57; 21, 

p. 6

Notes: 

EPA U.S. Environmental Protection Agency 

GMBVAS Great Miami Buried Valley Aquifer System 

GW Ground water 

ID Identification number 

msl Mean sea level 

MW Monitoring well 
33 GW-Likelihood of Release

Background Concentrations

The background ground water samples listed in Table 8 of this HRS documentation record were collected 

during the EPA October 2014 sampling event (Ref. 21, pp. 5, 6, 8). The background ground water 

samples were collected north, northeast, east, and southeast (upgradient and sidegradient) of Source No. 1 

(see Figure 3 of this HRS documentation record). The background ground water samples were analyzed 

for VOCs by Pace Analytical using the EPA SW-846 Method 8260B (Ref. 15, pp. 152, 157, 165, 167, 

169, 171, 189, 199). The EPA conducted a Stage 4 data validation of the Pace analytical data package in 

accordance with the EPA Guidance for Labeling Externally Validated Laboratory Analytical Data for 

Superfund Use and the EPA Contract Laboratory Program (CLP) NFG for Superfund Organic Methods 

Data Review (Ref. 15, pp. 82, 108, 157, 174). The data validation effort shows the overall data quality to 

be acceptable (Ref. 15, pp. 142 to 146, 157 to 161, 189 to 193). 

The analytical data results are provided in Appendix D of Reference 15. The reporting limits are listed on 

the analytical data sheets in Reference 15. The reporting limits are adjusted for sample characteristics 

that may affect quantitation, such as dilutions and concentration (Refs. 15, pp. 152, 165, 167, 169, 171, 

199; 35). The reporting limits are equivalent to SQLs as defined in Section 1.1, Definitions of the HRS 

(Refs. 1, p. 51586; 35). 

TABLE 8: Background Ground Water Concentrations – October 2014

Sample ID

Hazardous 

Substance

Concentration 

(mg/L)

Reporting 

Limit 

(mg/L) References

GW-MW-5-101414 PCE 0.005 U 0.005 15, p. 165

GW-MW-6-101414 PCE 0.005 U 0.005 15, p. 167

GW-MW-EPA-9-101614 PCE 0.005 U 0.005 15, p. 199

GW-MW-EPA-11-101314 PCE 0.005 U 0.005 15, p. 152

GW-MW-EPA-12-101414 PCE 0.005 U 0.005 15, p. 169

GW-MW-EPA-13-101414 PCE 0.005 U 0.005 15, p. 171

Notes: 

EPA U.S. Environmental Protection Agency 

ID Identification 

mg/L Milligrams per liter 

MW Monitoring well 

PCE Tetrachloroethylene 

U Compound was analyzed for, but not detected at or above the associated value (report limit) (Ref. 15, p. 66) 
34 GW-Likelihood of Release

Contaminated Samples

Ground water samples listed in Table 9 of this HRS documentation record were collected during the EPA 

October 2014 sampling event from permanent monitoring wells completed within the sand and gravel unit 

of the GMBVAS located downgradient of Source No. 1 (Refs. 15, pp. 32, 46, 47, 58, 59; 21, pp. 7, 8) (see 

Figures 3 and 4 of this HRS documentation record). All ground water samples were collected in 

accordance with the EPA-approved field SAP dated September 2014 (Ref. 15, p. 8). 

The contaminated ground water samples and their corresponding top of casing elevations and screened 

intervals are provided in Table 9 of this HRS documentation record. Results for contaminated ground 

water samples collected downgradient of Source No. 1 were compared with background samples 

completed within the sand and gravel unit of the GMBVAS at similar screened intervals (Refs. 15, pp. 10, 

32, 35, 48 to 58; 18, pp. 179, 183, 206, 207, 211, 212; 33) (see Tables 9 and 10 of this HRS 

documentation record). 

The locations of the contaminated ground water samples are contained in Reference 15, pp. 25, 32 (see 

Figure 4 of this HRS documentation record). Well construction diagrams are provided in References 9 

and 15, p. 35, Appendix B, pp. 46, 47, 58, and 59. Chain-of-custody forms (which provide the sample 

identification numbers and date and time of sample collection) are provided in Reference 21, pages 7 and 

8. 

TABLE 9: Contaminated Ground Water Samples – October 2014

Sample ID

GMBVAS

Zone

Top of 

Casing 

Elevation

(feet msl)

Well Screen 

Interval

(feet msl)

Date

Sampled Location References

GW-PW-101514 Shallow 784.32 745.35 to 

735.35 10/15/2014 MW-PW(Old PW)

9; 15, p. 

35; 21, p. 

7

GW-MW-EPA-8-

101414 Shallow 781.5 751.8 to 741.8 10/15/2014 MW-EPA-8

9; 15, pp. 

35, 46, 47; 

21 p. 7

GW-MW-EPA14-101614 Shallow 780.57 751.07 to 

741.07 10/16/2014 MW-EPA-14

9; 15, pp. 

35, 58, 59; 

21 p. 8

Notes: 

EPA U.S. Environmental Protection Agency 

ID Identification number 

GMBVAS Great Miami Buried Valley Aquifer System 

msl Mean sea level 

MW Monitoring well 

PW Production well 
35 GW-Likelihood of Release

Contaminated Concentrations

The contaminated ground water samples listed in Table 10 of this HRS documentation record were 

collected during the EPA October 2014 sampling event (Refs. 15, pp. 184, 186, 201; 21, pp. 7, 8). The 

contaminated ground water samples were collected from permanent monitoring wells located 

downgradient of Source No. 1 (see Figure 4 of this HRS documentation record). The contaminated 

ground water samples were analyzed for VOCs by Pace Analytical using the EPA SW-846 Method 

8260B (Ref. 15, pp. 174 to 178, 185, 186, 189 to 193, 201). 

EPA conducted a Stage 4 data validation of the Pace Analytical data package in accordance with the EPA 

Guidance for Labeling Externally Validated Laboratory Analytical Data for Superfund Use and the EPA 

CLP NFG for Superfund Organic Data Review (Ref. 15, pp. 174, 189). The data validation effort shows 

the overall data quality to be acceptable (Ref. 15, pp. 174 to 178, 184, 186, 189 to 193, 201). 

The reporting limits are listed on the analytical data sheets in Reference 15. The reporting limits are 

adjusted for sample characteristics that may affect quantitation, such as dilutions and concentration (Refs. 

15, pp. 184, 186, 201; 35). The reporting limits are equivalent to SQLs as defined in Section 1.1, 

Definitions of the HRS (Refs. 1, p. 51586; 35). 

TABLE 10: Contaminated Ground Water Analytical Results – October 2014 

Sample ID

Hazardous 

Substance

Concentration 

(mg/L)

Reporting 

Limit 

(mg/L) References

GW-PW-101514 PCE 0.028 0.005 15, p. 186; 21, p. 7

GW-MW-EPA-8-101514 PCE 19.3 0.50 15, p. 184; 21, p. 7

GW-MW-EPA-14-101614 PCE 2.5 0.10 15, p. 201; 21, p. 8

Notes: 

EPA U.S. Environmental Protection Agency 

ID Identification 

mg/L Milligrams per liter 

MW Monitoring well 

PCE Tetrachloroethylene 

PW Production well 
36 GW-Likelihood of Release

Attribution

For HRS scoring purposes, the Valley Pike VOCs site is composed of Source No. 1, dry/injection well 

DW-2, and an observed release of PCE and TCE to the shallow sand and gravel zone of the GMBVAS

(Refs. 8, pp. 144, 150, 153, 219, 234, 237; 15, pp. 152, 165, 167, 169, 171, 184, 186, 199, 201; 17, pp. 29, 

30, 37, 103, 122, 128; 33). The MRP property is located at 2949 Valley Pike in Riverside, Ohio (Ref. 14, 

p. 3). MRP began operations at this location in 1942 and continues to operate at the property (Refs. 6, p. 

2; 11, p. 2; 14, p. 3). MRP has informed EPA that TCE has been used at the facility since approximately 

1968 (Ref. 14, p. 4). Currently, as part of the MRP manufacturing process, metal and steel parts are 

degreased with TCE in two vapor degreasers before they are bonded with rubber parts (Refs. 6, p. 4; 14, 

pp. 3, 4; 15, p. 4). The vapor degreasers are located in the northwestern portion of the manufacturing 

area, near the north end of the building (see Figure 3 of this HRS documentation record) (Ref. 15, p. 4). 

According to MRP, since the vapor degreasers were installed in 1994, TCE has been used and continues 

to be used in the vapor degreasers (Ref. 14, pp. 3, 4). MRP currently purchases TCE in 55-gallon drums 

for use in its vapor degreasers (Ref. 14, p. 3). Spent TCE that can no longer be used for degreasing parts 

is stored in sealed drums for disposal on a quarterly basis (Ref. 14, p. 3). 

As a result of its TCE use, MRP is required to report TCE usage annually to RAPCA. After an 

anonymous source alleged that MRP was under-reporting the amount of solvents used, Ohio EPA and 

RAPCA performed an unannounced inspection on May 14, 2001 (Ref. 7, p. 4). RAPCA and Ohio EPA 

determined that MRP had under-reported its TCE usage, kept false records, and knowingly reported false 

data from 1995 to 2000 (Ref. 7, p. 4). In January 2004, a seven-count criminal indictment was filed 

against MRP by the U.S. Attorney’s Office in Dayton, Ohio (Ref. 7, p. 5). From 1995 to 1999, the 

combined emissions permit limit was 10,000 pounds per year (Ref. 7, p. 4). However, actual emissions 

were calculated and ranged from 17,679 pounds in 1996 to 38,556 pounds in 1997 (Ref. 7, pp. 4, 5). 

Later the same year, William R. Mullins, president of MRP, pled guilty to making false statements in 

reporting airborne discharges of TCE and failing to submit a Title V air permit by the October 1996 

deadline (Ref. 7, p. 5). MRP now holds a Clean Air Act Title V operating permit that was issued January 

16, 2008 (Ref. 7, p. 5). In accordance with MRP’s Title V permit, the facility’s TCE usage is a rolling 

12-month limit of 15.54 tons (Ref. 7, p. 5). 

MRP was aware that they were drawing cooling water from a well that contained PCE- and TCEcontaminated ground water (Ref. 40, p. 1). A ground water sample collected from an MRP production 

well located on the eastern side of the MRP building contained PCE at 156 mg/L (Ref. 17, pp. 4, 13, 103). 

After circulating through the vapor degreasers, the water was discharged into dry/injection wells on the 

property (Refs. 14, p. 4; 40, pp, 1, 2). Until 2012, MRP used seven dry/injection wells, including Source 

No. 1, to manage non-contact cooling water, storm drainage, and boiler blowdown water (Refs. 7, p. 4; 

15, p. 4). Based on the dates of installation, the dry/injection wells were used as early as 1972 (Refs. 14, 

pp. 35, 48; 15, p. 42; 17, p. 128). A log for dry/injection well, DW-2, installed on MRP property

indicates that the 50-foot well is a “return dry well, used for returning water back to ground;” however, 

the well is completed at 50 feet bgs through an upper clay layer and into the shallow zone of the 

underlying sand and gravel zone of the GMBVAS (Refs. 14, pp. 35, 48; 15, p. 42; 17, p. 128). Therefore, 

DW-2 discharged water directly into the underlying aquifer (Refs. 14, pp. 4, 48; 17, pp. 5, 12, 13). 

Some of the MRP dry/injection wells were reportedly interconnected (Ref. 15, pp. 4, 41). The MRP wells 

were considered Class V injection wells under the Ohio UIC Program (Refs. 7, p. 4; 8, pp. 2, 3; 38). 

Permits were not issued, but the wells were registered with Ohio EPA (Refs. 7, p. 4; 8, pp. 2, 3). In 2012, 

Ohio EPA required MRP to terminate use of the wells based on the presence of PCE in local ground 

water (Refs. 8, p. 3; 14, p. 4). Also in 2012, MRP installed a closed loop chiller system that eliminated 

the need to discharge non-contact cooling water into the injection wells (Ref. 14, pp. 3, 4).

PCE and TCE were detected in samples collected from Source No. 1 (Refs. 8, pp. 152, 153, 160 to 167; 

17, pp. 27, 28, 100, 103, 126; 33). These detections were documented before the closed loop system was 

installed in 2012 (Refs. 8, pp. 98, 153, 237; 17, pp. 29, 30, 37) (see Tables 1 and 2 of this HRS 

documentation record).
37 GW-Likelihood of Release

Analysis of samples collected in the vicinity of the Valley Pike VOCs site has indicated the presence of 

PCE or TCE in ground water, soil, and sub-slab vapor (Ref. 7, pp. 2, 9). Sub-slab vapor samples 

collected beneath the MRP main building in September 2014 had high levels of PCE and TCE (Ref. 7, p. 

2). PCE was detected between 44.1 and 3,550,000 μg/m3

and TCE between 104 and 44,400 μg/m3(Ref. 

7, pp. 9, 10, 22). The highest detection of PCE (3,550,000 μg/m3) was in a sub-slab sample collected near 

the degreaser (Ref. 7, p. 2). Information provided by MRP states that MRP has historically used and 

currently uses TCE (Ref. 14, pp. 1, 3).

Subsurface soil samples collected downgradient of Source No. 1 (dry/injection well DW-2) and the 

former degreaser contained PCE and TCE. PCE concentrations ranged from 0.014 milligrams per 

kilogram (mg/kg) to 2,040 mg/kg (Refs. 15, pp. 30, 95, 99, 118, 126; 21, pp. 2, 3). More specifically, 

PCE was detected at the following concentrations in subsurface soil samples: at 0.043 mg/kg in sample 

SB-MW-EPA-7-1517, collected in the vicinity of the former degreaser at a depth of 15 to 17 feet bgs; at 

0.032 mg/kg and 2,040 mg/kg in samples SB-MW-EPA-8-1315 and SB-MW-EPA-8-2426, collected on 

the western side of the MRP building and downgradient of Source No. 1 at depths of 13 to 15 feet bgs and 

24 to 26 feet bgs, respectively; and at 0.014 mg/kg in subsurface soil sample SB-MW-EPA-14-1820, 

collected downgradient of Source No. 1 at 18 to 20 feet bgs (Ref. 15, pp. 30, 95, 99, 118, 126; 21, pp. 2, 

3). In addition, TCE was detected in subsurface soil samples collected from SB-MW-EPA-8-2022 at 2.6 

mg/kg between 20 to 22 feet bgs and SB-MW-EPA-8-2426 at 411 mg/kg between 24 to 26 feet bgs (Refs. 

15, pp. 30, 97, 99; 21, p. 2).

An observed release to the shallow zone of the GMBVAS is documented in ground water samples 

collected from permanent monitoring wells located downgradient of Source No. 1 (see Tables 9, 10, 11 

and 12 in Section 3.1.1 of this HRS documentation record). The highest detection of PCE in ground 

water was 19.3 milligrams per liter (mg/L) in sample GW-MW-EPA-8-101514 collected from permanent 

monitoring well MW-EPA-8 (Ref. 15, pp. 32, 184). Further, PCE (up to 300 μg/L) and TCE (up to 22 

μg/L) were detected in a ground water sample collected from permanent monitoring well MW-3 located 

on the southwestern corner (crossgradient of Source No. 1) of the MRP property (Ref. 8, pp. 11, 23, 346, 

347, 362). 

In addition, grab ground water samples were collected during the SI (Ref. 17, pp. 5, 6, 13). The highest 

detections of PCE (58 μg/L) and TCE (11 μg/L) were detected in grab ground water sample GW-6, 

located south and sidegradient of Source No. 1 on the southwestern corner of the MRP property (Ref. 17, 

pp. 13, 27, 28). 

The MRP facility is located in a commercial and industrial area of Riverside, Ohio (Ref. 8, p. 7) (see 

Figures 1 and 2 of this HRS documentation record). The properties located between the MRP property 

and Harshman Road to the northeast and Hypathia Avenue to the west include a church, retail and 

restaurant properties, and trucking, freight, and auto repair businesses (Ref. 15, pp. 2, 24). 

During the EPA October 2014 sampling event, properties in this area were evaluated as possible sources 

of VOC contamination. Properties where VOC contamination was detected included: MRP, Paul’s 

Garage, and Rockcastle Storage (Ref. 15, p. 5). 

Paul’s Garage is an automotive service facility and long-term storage facility for recreational vehicles 

(Ref. 15, p. 5). PCE was detected in a ground water sample collected from well MW-EPA-14 at 2.5 mg/L 

(Ref. 15, pp. 32, 201). Well MW-EPA-14 is located on the northeastern edge of the Paul’s Garage 

property, bordering the MRP property, and is downgradient from Source No. 1 (see Figure 4 of this HRS 

documentation record). The facility includes a metal building, a residence, and an area for storing large 

campers and boats (Ref. 15, p. 5). Paul’s Garage began operations in the 1960s (Ref. 15, p. 5). The 

property was originally part of the same property as MRP but does not appear to have been used for MRP 

operations (Ref. 15, p. 5). According to information provided by Paul’s Garage, a 500-gallon 

underground storage tank (UST) that contained waste oil was present off the northwest corner of the 

building (Ref. 15, p. 5). The UST was used from 1973 to 1985 and was subsequently removed with State 
38 GW-Likelihood of Release

of Ohio oversight (Ref. 15, p. 5). According to the information provided, a ground water monitoring well 

installed directly downgradient of the UST was sampled and no further action was required (Refs. 15, p. 

5; 36). Analytical results of the sample collected are not provided (Ref. 15, p. 5). Available information 

does not indicate the presence of any dry wells or productions wells at the Paul’s Garage property. Based 

on its operations, it is possible that solvents such as PCE and TCE were used to degrease automobile 

parts (Refs. 15, p. 5; 36; 37). 

Rockcastle Storage, located northeast and crossgradient of the Valley Pike VOCs site, is shown in Figure 

2 of this HRS documentation record. PCE was detected in October 2014 at 0.034 mg/L in ground water 

sample GW-MW-EPA-10-101314 collected from permanent monitoring well MW-EPA-10, located east 

and crossgradient of Source No. 1 on the Rockcastle Storage property (Ref. 15, pp. 9, 32, 148). 

Rockcastle Storage was constructed in the 1980s (Ref. 15, p. 5). Historical aerial photographs show that 

the land was undeveloped before that time (Ref. 15, p. 5). The facility includes a front office at the east 

end of the property that is also used as a residence by the site manager (Ref. 15, p. 5). Six rows of 

storage structures are west of the office and, together with the access driveways, cover most of the 

property (Ref. 15, p. 5). A large dry well/stormwater basin is within the only unpaved area, at the 

southern end of the property (Ref. 15, p. 5). Based on its operations, it is unlikely that Rockcastle 

Storage is a contributor to ground water contamination. During the same EPA 2014 investigation, PCE 

concentrations in ground water downgradient of Source No. 1 were more than 500 times higher (19.3 mg/

L) than that detected at Rockcastle Storage (Ref. 15, pp. 32, 148, 184).

TCE was used at MRP for metal degreasing operations (Ref. 14, pp. 3, 4). PCE and TCE have been 

detected in samples collected from Source No. 1 (Ref. 15, p. 30) (see Tables 1 and 2 of this HRS 

documentation record). In addition, an observed release of PCE and TCE by direct observation and 

chemical analysis has been detected in ground water samples collected from permanent monitoring wells 

completed in the sand and gravel unit of the GMBVAS (Ref. 15, pp. 31 and 32) (see Tables 9, 10, 11 and 

12 in Section 3.1.1, Observed Release of this HRS documentation record). The hazardous substances 

listed below have been documented in Source No. 1 on the MRP property (see Tables 1 and 2 in Section 

2.2.2, Source No. 1 and Tables 6 through 10 in Section 3.1.1, Observed Release of this HRS 

documentation record). 

No NPL sites are located within 1 mile of the Valley Pike VOCs site (Ref. 39, pp. 1 to 6). VOCs have 

been detected in ground water at the Wright Patterson Air Force Base and the Behr Dayton Thermal 

System VOC NPL site, located approximately 1.5 miles east-southeast and 2 miles northeast from Source 

No. 1 at the Valley Pike VOCs site, respectively (Ref. 39, pp. 1 to 6). However, low or non-detect results 

of PCE and TCE in ground water, soil, and sub-slab vapor samples collected from the eastern and 

southern portions of the MRP property indicate that an off-site source of PCE and TCE is not influencing 

Source No. 1 and ground water downgradient of Source No. 1 at MRP (Ref. 39, pp. 1 to 6). 

Though not scored as part of this site, a Settlement Agreement signed in January 2016, between U.S. EPA 

and MRP identified the (larger) Valley Pike VOC Site as containing a residential area with documented 

vapor intrusion from a PCE- and TCE-contaminated, shallow ground water plume (Ref. 51, p. 4). The 

residential area includes about 500 residences and is located approximately 900 feet southwest of MRP

(Ref. 51, p. 4). The Settlement Agreement identifies the MRP facility as the source of the ground water

plume (Ref. 51, p. 4).

Hazardous Substances in the Release

The following substances have been documented in an observed release to the ground water migration 

pathway by direct observation and/or by chemical analysis.

PCE 

TCE 

Ground Water Observed Release Factor Value: 550.00 
39 GW-Waste Characteristics

3.1.2 POTENTIAL TO RELEASE

Potential to release was not evaluated because an observed release to the shallow sand and gravel zone of 

the GMBVAS, which includes the sand and gravel unit, has been documented (see Section 3.1.1 of this 

HRS documentation record). 

3.2 WASTE CHARACTERISTICS

3.2.1 TOXICITY/MOBILITY

The toxicity and mobility factor values for the hazardous substances detected in the source samples with 

containment factor values of greater than 0 are summarized in Table 11 of this HRS documentation 

record. The combined toxicity and mobility factor values are assigned in accordance with Reference 1, 

Section 3.2.1. Hazardous substances detected in the observed release to ground water are assigned a 

mobility factor value of 1 (Ref. 1, Section 3.2.1.2).

TABLE 11: Ground Water Toxicity/Mobility

Hazardous

Substance

Source 

No.

Toxicity 

Factor

Value

Mobility

Factor 

Value

Does Hazardous 

Substance Meet 

Observed 

Release? 

(Yes/No)

Toxicity/

Mobility

(Ref. 1, 

Table 3-9) Reference

PCE 1 100 1

1 Yes 100 2, p. 1

TCE 1 1,000 1 Yes 1,000 2, p. 3

Notes:

1

 Tetrachloroethylene was detected in Source No. 1 and as an observed release in ground water. Therefore, a mobility 

factor value of 1 was assigned in accordance with the HRS (Ref. 1, p. 51601, Section 3.2.1.2).

No. Number

Toxicity/Mobility Factor Value: 1,000

(Ref. 1, Table 3-9)
40 GW-Waste Characteristics

3.2.2 HAZARDOUS WASTE QUANTITY

TABLE 12: Hazardous Waste Quantity

Source No. Source Type Source Hazardous Waste Quantity

1 Other >0

Based on HRS Section 2.4.2.2, if there has been no removal action, a factor value from Table 2-6 or

a value of 10, whichever is greater, is assigned as the Hazardous Waste Quantity Factor Value for

that pathway (Ref. 1, pp. 51591, 51592 [Section 2.4.2.2]). This factor is assigned because the

Hazardous Constituent Quantity is not adequately determined for Source No. 1, none of the targets

for the ground water migration pathway is subject to Level I or Level II concentrations, and there 

has been no removal action.

Hazardous Waste Quantity Factor Value: 10

(Ref. 1, Section 2.4.2.2, Table 2-6)

3.2.3 WASTE CHARACTERISTICS FACTOR CATEGORY VALUE

For waste characteristics, TCE has the highest toxicity/mobility factor value (Ref. 2, p. 3). The waste 

characteristics factor category value was obtained by multiplying the toxicity/mobility and HWQ factor 

values, subject to a maximum product of 1 × 108. Based on this product, a value was assigned in 

accordance with Reference 1, Table 2-7.

Toxicity/Mobility Factor Value: 1,000

Hazardous Waste Quantity Factor Value: 10

Toxicity/Mobility Factor Value × 

Hazardous Waste Quantity Factor Value: 1 x 104

Waste Characteristics Factor Category Value: 10

(Reference 1, Table 2-7)
41 GW-Targets

3.3 TARGETS

Residents within a 4-mile radius of Source No. 1 at the Valley Pike VOCs site are provided drinking 

water by the City of Dayton Water Department (Refs. 3; 12, p. 1). The Dayton Water Department 

supplies drinking water to about 400,000 people (Ref. 12, p. 1). This population includes water sold by 

the City of Dayton Water Department to Montgomery County, and the cities of Brookville, Trotwood, 

and Oakwood water departments (Ref. 12, p. 1). The Dayton Water Department maintains 109 wells in 

two well fields, the Mad River Well Field and Miami Well Field (Refs. 3; 12, p. 3; 20, pp. 1, 2). 

Water from the Mad River Well Field is treated at the Ottawa Water Treatment Plant and serves residents 

on the south side of Dayton (Ref. 12, p. 3). Water from the Miami Well Field is treated at the Miami 

Water Treatment Plant and serves residents on the north side of Dayton (Ref. 12, p. 3). Water from each 

well field is mixed at the respective water treatment plant and distributed (Ref. 12, pp. 1, 3). During 

distribution, water from the two water treatment plants mixes in the water distribution lines, forming a 

blended system (Refs. 12, pp. 1, 3). None of the municipal wells produce more than 40 percent of the 

total Dayton water supply (Ref. 12, p. 3). The locations of the City of Dayton Water Department 

municipal wells in the Mad River and Miami well head protection areas are depicted on Reference 3. The 

number of wells in each distance ring of the 4-mile radius of Source No. 1 is presented in Table 14 of this 

HRS documentation record. The Dayton Water Department does not maintain additional emergency or 

standby wells (Ref. 12, p. 3).

The City of Dayton Water Department municipal wells withdraw drinking water from the GMBVAS, a 

federally designated “Sole Source Aquifer,” which implies that it serves as a sole or principal source of 

drinking water for the area and which, if contaminated, would significantly increase risk to the public 

(Refs. 12, p. 3; 13, p. 4). Wellhead protection areas are delineated around the City of Dayton Water 

Department well fields, which is part of a multi-jurisdictional Well Field Protection Program (Refs. 12, p. 

3; 20; 32).

3.3.1 NEAREST WELL

Well ID: PW-06, City of Dayton Water Department well located northeast of Eastwood Lake and 

Harshman Road (Refs. 3; 48)

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

If potential contamination, distance from source in miles: 0.53 mile 

Nearest Well Factor Value: 9

(Refs. 1, Table 3-11; 48) 

3.3.2 POPULATION

3.3.2.1 Level of Contamination

3.3.2.2 Level I Concentrations

Level I concentrations were not scored in this HRS documentation record. 

3.3.2.3 Level II Concentrations

During the December 2011 Ohio EPA ESI, ground water samples were collected from nine City of 

Dayton Water Department municipal wells located down-gradient of Source No. 1 (Ref. 8, pp. 12, 13, 

21). PCE, TCE, and other volatile organic compounds were detected in six of the nine wells (Ref. 8, pp. 

12, 13, 99, 100, 177, 180, 181, 186, 187, 188, 189, 191, 193, 213, 214, 215, 271, 276, 277, 285, 286, 288, 
42 GW-Targets

289, 292, 295). Based on available data, attribution of this contamination to Source No. 1 cannot be 

established at this time. Therefore, Level II concentrations were not scored in this HRS documentation 

record. The population served by the City of Dayton Water Department are evaluated under Section 

3.3.2.4 of this HRS documentation record.

3.3.2.4 Potential Contamination

Potential contamination targets for the ground water migration pathway include the population served by 

the City of Dayton Water Department (Ref. 12, pp. 1, 2). This population includes residents in the City of 

Dayton as well as Montgomery County, and the nearest cities of Brookville, Trotwood, and Oakwood 

(Ref. 12, p. 1). According to the City of Dayton Water Department, the department provides water to 

400,000 residents from a blended system of 109 wells (Refs. 3; 12, p. 1; 20).

Population served per well is 3,669.72 people (400,000 residents ÷ 109 wells = 3,669.72 people per well) 

(Refs. 3; 12, pp. 1, 3; 20).

Distance-weighted population values for potential contamination ground water targets for the GMBVAS 

are presented in Table 13 of this HRS documentation record (Refs. 1, Section 3.3.2.4; 3; 12, pp. 1, 2). 

TABLE 13: Distance-Weighted Population Values – Non-Karst Aquifers

Distance Category

(Miles)

Number 

of Wells

Population

(Number of wells x 

3,669.72)

Distance-Weighted 

Population Value

(Ref. 1, Table 3-12) References

Greater than 0 to 0.25 0 0 0 3; 12, p. 1; 20

Greater than 0.25 to 0.5 0 0 0 3; 12, p. 1; 20

Greater than 0.5 to 1 27 99,082.44 16,684 3; 12, p. 1; 20

Greater than 1 to 2 63 231,192.36 29,384 3; 12, p. 1; 20

Greater than 2 to 3 17 62,385.24 6,778 3; 12, p. 1; 20

Greater than 3 to 4 2 7,339.44 417 3; 12, p. 1; 20

Sum of Distance Weighted Population Value 53,263

Sum of Distance-Weighted Population Values: 53,263

Sum of Distance-Weighted Population Values ÷ 10: 5,326 (rounded to nearest integer)

Potential Contamination Factor Value: 5,326

3.3.2.5 CALCULATION OF POPULATION FACTOR VALUE

The total population factor value is the sum of the potential contamination factor, the Level I actual 

contamination, and the Level II actual contamination factor values (Ref. 1, Section 3.3.2.5). A value of 

5,326 is assigned for the population factor value. 

Population Factor Value: 5,326
43 GW-Targets

3.3.3 RESOURCES

Municipal water obtained from the City of Dayton Water Department is used to fill swimming pools 

including the Forest Ridge Association Pool (Ref. 49). A value of 5 is assigned for the resources factor 

value (Ref. 1, Section 3.3.3). 

TABLE 14: Resources

Area Use Value References

City of Dayton, Miami 

and Mad River Well 

Fields

Supply for a major or designated water 

recreation area, excluding drinking 

water use. Municipal water obtained 

from wells maintained by the City of 

Dayton Water Department that are used 

to fill swimming pools at local 

recreational centers

5 32

Resources Factor Value: 5

3.3.4 WELLHEAD PROTECTION AREA

Wellhead Protection Areas for the Miami and Mad River Well Fields are located within a 4-mile radius of 

Source No. 1 (Refs. 3; 12, p. 3; 20; 32). The City of Dayton Well Field Protection Program provides 

restrictions on zoning and water use regulations within the well field protection area and is in accordance 

with Section 1428 of the Safe Drinking Water Act, as amended (Refs. 32; 34; 42). A value of 5 is 

assigned for the wellhead protection area factor value (Ref. 1, Section 3.3.4).

Wellhead Protection Area Factor Value: 5