HRS DOCUMENTATION RECORD

-- REVIEW COVER SHEET

Name of Site: Baghurst Drive

EPA ID No.: PAN000306939

Date Prepared: May 2014

Contact Person Lorie Baker
U.S. Environmental Protection Agency Philadelphia

, Pennsylvania (215) 814

- 3355 Baker.Lorie@epa.gov

Pathways, Components, or Threats Not Scored

The surface water migration, soil exposure, and air migration pathways are not scored in this Hazard Ranking System (HRS) documentation record because the listing decision is not significantly affected by those pathways.
T he ground water migration pathway score is sufficient to qualify the site for National Priorities List (NPL).Th is page has been left blank intentionally.1 HRS DOCUMENTATION RECORD

Name of Site: Baghurst Drive Date Prepared: May 2014

CERCLIS ID No.: PAN000306939

EPA Region: 3

Street Address of Site *: Northern Intersection of Hendricks Road and Baghurst Drive

County and State: Harleysville

, Montgomery County, Pennsylvania 19438

General Location in the State: S outheastern Pennsylvania

Topographic Map: Perkiomenville, PA

Latitude: * 40  ̊ 17 ' 58.14 " North Longitude: *75  ̊ 27 ' 18.48 " West (40.299483  ̊ North) (75.455133  ̊ West)

The site consists of a ground water plume with no identified source(s) of contamination. Therefore, the reference point for the street address and site latitude/longitude coordinates is located within the plume at the intersection of Hendricks Road and Baghurst Drive as shown on Figure 1 of this HRS documentat i on record (Ref s. 3; 4; 5 ).

* The street address, coordinates, and contaminant locations presented in this HRS documentation record identify the general area the site is located. They represent one or more locations EPA considers to be part of the site based on the screening informatio n 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 h azardous substance has been "deposited, stored, disposed, or placed, or has 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 addresse d under 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.

Scores

Ground Water Pathway 100.00 Surface Water Pathway Not Scored Soil Exposure Pathway Not Scored Air Pathway Not Scored

HRS SITE SCORE 50.002 WORKSHEET FOR COMPUTING HRS SITE SCORE Baghurst Drive

S S 2

1. Ground Water Migration Pathway Score (S gw ) 100.00 10,000 (from Table 3

- 1, line 13)

2a. Surface Water Overland/Flood Migration Component Not Scored (from Table 4

- 1, line 30)

2b. Ground Water to Surface Water Migration Component Not Scored (from Table 4

- 25, l ine 28)

2c. Surface Water Migration Pathway Score (S
sw ) Not Scored Enter the larger of lines 2a and 2b as the pathway score.

3. Soil Exposure Pathway Score (S
s ) Not Scored (from Table 5

- 1, line 22)

4. Air Migration Pathway Score (S
a ) Not Scored (from Table 6

- 1, line 12)

5. Total of S gw 2 + S
sw 2 + S
s 2 + S
a 2 10,000

6. HRS Site Score Divide the value on line 5 by 4 and take the square root 50.003 GROUND WATER MIGRATION PATHWAY SCORESHEET Baghurst Drive

GROUND WATER MIGRATION PATHWAY Factor Categories & Factors MAXIMUM VALUE VALUE ASSIGNED

Likelihood of Release
1. Observed Release 550 550
2. Potential to Release
2a. Containment 10 N ot scored
2b. Net Precipitation 10 N ot scored
2c. Depth to Aquifer 5 N ot scored
2d. Travel Time 35 N ot scored
2e. Potential to Release [lines 2a(2b+2c+2d)] 500 N ot scored

3. Likelihood of Release 550 550

Waste Characteristics
4. Toxicity/Mobility * 10,000
5. Hazardous Waste Quantity * 100

6. Waste Characteristics 100 32

Targets
7. Nearest Well 50 50
8. Population
8a. Level I Concentrations ** 541. 7 0
8b. Level II Concentrations ** 1
8c. Potential Contamination ** N ot scored
8d. Population (lines 8a+8b+8c) ** 542. 7 0
9. Resources 5 N ot scored
10. Wellhead Protection Area 20 N ot scored
11. Targets (lines 7+8d+9+10) ** 592. 7 0

12. Aquifer Score (lines 3x6x12 divided by 82,500) 100 100 .00

13. Ground Water Migration Pathway Score (Sgw) 100 100.00

* Maximum value applies to waste characteristics category.

** Maximum value not applicable.4 REFERENCES

Reference
Number Description of the Reference

1. U.S. Environmental Protection Agency (EPA). Hazard Ranking System, Final Rule . Federal Register, Volume 55, No. 241, pp. 51532



### – 51667. December 14, 1990. Cover page only. A complete copy of
the rule is available at http://www.epa.gov/superfund/sites/npl/hrsres/index.htm#HRS Rule

. [ 1 page ]

2. U.S. Environmental Protection Agency ( EPA )

. Excerpts from Superfund Chemical Data Matrix, Appendices B- I (Hazardous Substances Factor Values) and B

- II (Hazardous Substance Benchmarks)

. SCDM Data Version: 12/31/12

. Publication date 1/30/2014. A complete copy of SCDM is available at http://www.epa.gov/superfund/sites/npl/hrsres/tools/scdm.htm

. [ 42 pages ]

3. U.S. Environmental Protection Agenc y ( EPA )

. Superfund Site Information, Baghurst Alley

, Harleysville, PA: Site Information . Downloaded from http://cumulis.epa.gov/supercpad/cursites/csitinfo.cfm?id=0306939 o n November 3, 2013 . [1 page]

4. U.S. Geological Survey (USGS). Perkiomen, Pennsylvania Quadrangle (7.5×7.5

- minute series topographic map). 2013 . [1 map]

5. Shannon, Nancy, Weston Solutions, Inc. (WESTON). Project Note to Baghurst Alley Site File: Aerial Photograph Indicating Site Latitude and Longitude

. Information Obtained from Google Earth® on February 12 , 201 4 . [ 2 page s]

6. Foster Wheeler Environmental Corporation. Final Site Characterization Report, Bag h urst Alley Site, Upper Salford Township, Montgomery County, Pennsylvania

. PADEP Contract No. 359 1 86. Work Requisition No. 31

- 118. April 2003 . [ 610 page s]

7. Weston Solutions, Inc. (WESTON ® ). Draft Hydrogeologic Report for the Baghurst Alley Site

. PADEP contract No. SAP#4000014758. PADEP Work Assignment No. IRRSC -6 . May 2013. [302 pages]

8. U.S. Environmental Protection Agency ( EPA )

. National Primary Drinking Water Regulations
Maximum Contaminant Levels

. http://water.epa .gov/drink/contaminants/upload/mcl

- 2.pdf May 2009

. [6 pages]

9. Pennsylvania D epartment of Environmental Protection (PADEP)

. HSCA Response Justification
Document - Baghurst Alley Site

. Upper Salford Township, Montgomery County

, Southeast Region

. November 23, 1999. [ 2 pages]

10. Pennsylvania Department of Environmental Protection (PADEP)

. Hazardous Sites Cleanup Program

. Statement of Decision, Baghurst Alley Site. November 7, 2001. [12 pages]

11. Weston Solutions, Inc. (WESTON ® )

. Well Installation, Groundwater Sampling, and Pump ing Test Report
– Baghurst Alley Site

. PADEP C ontract No. SAP#4000007413. PADEP Work Assignment
No. IRRSC5 -3- 131

. June 2008 [83 pages]

12. Armstrong, Dustin. Pennsylvania Department of Environmental Protection (PADEP)

. Excerpts from Baghurst Field Logbook s #1 and #2 . July 6 – October 12, 2011. [ 8 pages] *Hard Copy of Complete Logbook Available Upon Request from PADEP.

13. Pennsylvania Department of Environmental Protection (PADEP)

. Bureau of Laboratories

. Analytical Report . July 15
– October 29, 2011. [ 192 pages]REFERENCES (continued)

Reference
Number Description of the Reference

14. Commonwealth of Pennsylvania. Ground

- water Resources of the Brunswick Formation in Montgomery and Berks Counties, Pennsylvania (Ground Water Report W 22)

. PA Department of
Internal Affai rs, Bureau of Topographic and G eologic Survey. 1965 [64 pages]

15. U.S. Environmental Protection Agency (EPA)

. Contract Laboratory Program (CLP). Modifications Updating SOM0 1.1 to SOM01.2; with attached excerpts from SOM01.1

. Amended: April 11, 2007. [117 pages]

16. Agency for Toxic Substances & Disease Registry (ATSDR). Division of Toxicology T oxFAQs , 1,1,1

- Trichloroethane , CAS # 71

- 55 -6

. July 2006 . [2 pages]

17. Agency for Toxic Substances & Disease Registry (ATSDR)

. Division of To x icology T oxFAQs

, Trichloroethylene , CAS # 79

- 01 -6 . July 2003. [2 pages]

18. Armstrong, Dustin, PADEP. Electronic Mail Correspondence with Nancy Shannon, WESTON

. Subject: Baghurst Alley Residential Sampling Procedures

. November 13 and 26 , 2013. [3 pages]

19. Tetra Tech FW. Addendum to Site Characterization Report
– Baghurst Alley Site. PADEP C ontract No . ME

- 359186. W ork R equisition No . 31

- 118. April 2004. [337 pages]

20. Shannon

, Nancy

. WESTON. Tele conference Record Regarding Potential Source Investigations Conducted by PADEP

. November 5, 2013

. [ 1 page ]

21. Shannon, Nancy. WESTON. Electronic Mail Correspondence with Mr. Dustin Armstrong, PADEP, Regarding Common Well Connections

. November 7- 12, 2013. [ 2 pages]

22. Reference Number Reserved.

23. U.S. Census Bureau. State and County Quick Facts for Montgomery County, Pennsylvania.
Downloaded from http://quickfacts.census.gov/qfd/ states/42/42091.html on April 3, 2014

. Last revised on March 27, 2014. [2 pages]

24. U.S. Environmental Protection Agency (EPA) and The National Environmental Laboratory
Accreditation Conference ( NELAC ) Institute. NELAC (National Environmental Laboratory Accreditation Conference), program information and accreditation of Lancaster Laboratories

. Accessed and downloaded from various websites ( http://www.epa.gov/nelac/

, http://www.nelac

institute.org/newnelap.php

, http://nelac

- institute.org/lams/labs/2128/ , and http://nelac

institute.org/lams/ labs/1349/ ) o n November 13, 20 13 . [ 4 pages ]

25. U.S. Environmental Protection Agency (EPA). Technical Fact Sheet
– 1,4

- Dioxane. Office of Solid Waste and Emergency Response. . January 2013. [5 pages]

26. Pennsylvania Department of Conservation and Natural Resources. Pennsylvania Groundwater Information System. Bureau of Topographic and Geological Survey. Information Accessed from http://www.dcnr.state.pa.us/topogeo/groundwater/pagwis/records/index.htm on November 27 , 2013

. [3 pages]

27. Reference Number Reserved

56 REFERENCES (continued)

Reference
Number Description of the Reference

28. Shannon, Nancy

, WESTON. Baghurst Alley Project Note To File: Correspondence with Dustin Armstrong, PADEP. February 12, 2014 [3 pages]

29. Shannon, Nancy, WESTON. Baghurst Alley Project Note To File: Envirofacts® Database Search

. February 16, 2014. [46 pages]

30. US GS. Microbial Degradation of Choroethenes in Ground Water Systems. Toxic Substances Hydrology Program. Information Accessed from http://toxics.usgs.gov/sites/solvents/chloroethene .html on February 19, 2014. [1 page]

31. Shannon, Nancy, WESTON. Baghurst Alley Project Note To File: LOQ Equivalent to HRS

- defined SQL

. February 19 , 2014 [ 1 page]

32. EPA. Quick Reference Fact Sheet EPA 540 -F- 94

- 028: Using Qualified Data to Document an Observed Release and Observed Contamination. Office of Emergency and Remedial Resp onse. November 1996. Available from http://www.epa.gov/superfund/sites/npl/hrsres/fact/docor oc.pdf

. [18

pages ]

33. Shannon, Nancy, WESTON. Baghurst Alley Project Note To File: Rock Formations for Completed Monitoring Wells

. February 20 , 2014 [1 page]

34. Shannon, Nancy, WESTON. Baghurst Alley Project Note To File: Ref. 13 PADEP Laboratory Data SQLs

. February 25, 2014. [1 page]

35. Shannon, Nancy, WESTON. Baghurst Alley Project Note To File: Persons Per Household Subject to
Level I or Level II Concentrations

. March 1, 2014. [1 page]

36. Morin, Roger H.; Senior, L isa A.; and Decker, Edward R., Fractured

- Aq uifer Hydrogeology from Geophysical Logs: Brunswick Group and L ockatong Formation, Pennsylvani a

. USGS Staff

-- Published Research. Paper 352. January 1, 2000. http://digitalcommons.unl.edu/usgsstaffpub/352 . [12 pages]SS

– Site Summary

7 SITE SUMMARY

The Baghurst Drive site ( EPA ID No. PAN000306939 ) consists of a contaminated ground water plume with no identified source, i.e., no clearly defined attribution to a specific source [Ref. 3]

. The hazardous substances associated with the site include 1,1,1

- trichloroethane (1,1,1

- TCA), 1,1

- dicloroethene (1,1

- DCE), trichloroethylene (TCE), vinyl chloride, and 1,4

- dioxane , which will be further discussed and documented in subseque nt sections of
this HRS documentation record

. The site is located in a rural, residential area in Harleysville , Montgomery County, Pennsylvania [ Ref. 4; Figure 1 ]. The site is reported to have impacted 27 residential drinking water wells , including

a common well with 10 hookups

, [Ref s. 10, p. 2 ; 2 1 , pp. 1

- 2]

. The geographic coordinates of the site are 40 ̊ 1 7 '
58.14 " (40. 299483 ) north latitude and 7 5  ̊ 27 ' 18.48 " ( 75.455133 ) west longitude

, as measured at the intersection of Hendricks Road and Baghurst Drive [ Ref. 5 ; Figure 1 ].

In 1999, a homeowner submitted a water sample to the Montgomery County Health Department (MCHD) per county regulations to receive a permit for a residential drinking water well. Analytical results of the water sample indicated concentrations of 1,1,1

- TCA above the EPA National Primary Drinking Water Standard Maximum Contaminant Level (MCL) of 200 micrograms per liter ( μg/L ) ( Ref s

. 6

, p. 12; 8 , p. 3 ). From June 1999 to October 1999, the MCHD collected samples from several residential drinking water wells i n the area and found the wells
contained one or more volatile organic compound s (VOC s ), such as 1,1

- DCE; 1,1,1

- TCA ; TCE ; and vinyl chloride

, as well as 1,1

- dichloroethane (1,1

- DCA) and 1,2

- dichloroethene (1,2

- DCE)

, at concentrations above MCLs [Ref. 6,

p. 12]

. In November 1999, MCHD contacted the Pennsylvania Department of Environmental Protection (PADEP) regarding the presence of chlorinated solvents in residential wells [ Ref. 9 , pp. 1

- 2 ]

. PADEP immediately began supplying 27 residences with bottled drinking water and subsequently equipped the homes with carbon filtration systems [Ref. 10 , p. 2]

.

In April 2001, PADEP contracted Foster Wheeler Environmental Corporation (Foster Wheeler) to conduct a source investigation for the VOCs detected in the res idential wells sampled by MCHD. The source investigation focused
on a 29

- acre farm property located on Hendricks Road

. The invest igation consisted of advancing soil borings, collecting soil samples, installing bedrock monitoring wells, collecting ground w ater samples from the monitoring wells between July 2001 and January 2003, and the collection of surface water samples from seeps and stream water in February, March

- April, and November 2002 [Ref 6 , p p. 7, 9, 22, 23, 38, and 55 ). Analytical results of the source investigation indicate d the presence of chlorinated VOCs (primarily 1,1,1

- TCA, 1,1

- DCE, 1,1

- DCA, vinyl chloride

, and TCE) in soil, ground water and surface water. The report concluded that t he core area of the highest chlorinated
VOC concentr ations in ground water (based on spatial concentrations) was located on a f arm p roperty on Hendricks
Road and ha d migrated approximately 800 feet downgradient [Ref. 6, pp. 55

, 56 , 73, and 74 ]. EPA has concluded, however, that based on the relatively low co ntaminant levels detected in a limited number of samples, the soil
contaminatio n detected between 2001 and 2002 on the farm property is not enough evidence to identify it as a primary or significant source of the ground water contamination and has been unable to identify a primary source (see the attribution discussion in Section 3.1.1 of this HRS documentation record for more detailed information pertaining to the unidentified origin of the contaminants).

In 2007 and 2012, PADEP installed wel ls and conducted pump tests in an effort to find an alternate, local, unaffected ground water source for the community [Refs. 7, pp. 8

- 9; 11 , p. 8 ]. However, the analysis of the ground water samples collected from the potential supply wells contained conc entrations of arsenic and le ad above their respective MCLs. The presence of arsenic and lead in the ground water was believed to be naturally occurring as a result of diabase intrusions into the Lockatong and Brunswick Formations. The source water from t hese potential supply wells would require treatment prior to distribution

. Additionally, a large pumping influence was observed in nearby residential drinking water wells during pump tests [Ref. 7, pp. 29, 31, 35 and 36]. As of the date of this HRS
docum entation record, the residents have not been connected to an alternative water supply. Affected residents continue to receive bottled water for drinking purposes [Ref. 28, pp. 1 and 3].

Since 2000, PADEP has periodically collecte d samples from residential homes that have filtrations systems to
monitor contaminant concentrations and filter performance [Ref. 2 8, p p. 1 and 3 ]. In Jan uary and March 2004, PADEP began analyzing for 1,4

- dioxane

, which was subsequently found in some of the affected wells (Ref. 19, p. 21). However, due to its high water solubility, 1,4

- dioxane is not removed by the filtration systems installed on the affected residential wells. Therefore, the affected residences a re supplied bottled water for drinking purposes.SS

– Site Summary

8 Additionally, while the systems effectively remove the other site

- related VOCs from the residential well water, the dermal/inhalation exposure to 1,4

- dioxane during bathing or washing is still a concern at the site [Ref. 7, p. 8].

# ^ _

TDD#: WS03-13-10-001 Contract: EP-S3-10-05 Prepared: 4/3/2014 

### Figure 1 Site Location Baghurst Drive PA State Plane, NAD83 

#  ́ Legend



# ^ _ Site Location

0 2,000 Feet Harleysville, Montgomery County, PA 1:24,000

Map Area USGS 7.5-Minute Series Topographic Quadrangles: Perkiomenville, Pennsylvania, 2013! 

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### A

TDD#: WS03-13-10-001 Contract: EP-S3-10-05 Prepared: 4/3/2014 

### Figure 2 Site Layout Baghurst Drive PA State Plane, NAD83 

#  ́ Legend

! 

### A Site Well

Source 1 0 1,000 Feet Harleysville, Montgomery County, PA 1:12,000

Map Area Note: The plume area shown on the map is based on the analytical data for wells that document an observed release contained in Refs. 7 and 13 of this HRS documentation record.

Service Layer Credits: Source: Esri, DigitalGlobe, GeoEye, i-cubed, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, swisstopo, and the GIS User Community! 

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### A

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### A

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### A

! 

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### A

! 

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### A

! 

### A ! 

### A

! 

### A

! 

### A

! 

### A

! 

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### A ! 

### A

! 

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### A ! 

### A ! 

### A ! 

### A ! 

### A ! 

### A

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### A !



### A & < & <

&

<

& <

& < & < & < & < & < & < & <

& <

& < & <

& < & <

& <

& < BAMW28 BAMW30 BAMW32

BAMW33

BAMW34 BAMW05 BAMW07 BAMW09 BAMW10 BAMW11 BAMW12 BAMW13

BAMW14

BAMW15 BAMW16 BAMW17 BAMW18

BAMW19 BAMW20

BAMW21 BAMW22

BAMW25 BAMW36

2096H

2179H

1760B

1744B 1746B 1780B 1800B 1810B

1747H 1775B

1767B 1787H 1836H 1886H 1898H 1926H

226'-41'

225'--146' 220'-60'

217'-28'

216'-86' 161'-54'

197'-52' 392'-22'

373'-243'

317'-157'

331'-133' 336'-78' 397'-92'

321'-43'

306'-51' 358'--2' 400'-220' 321'-154'

390'-130' 390'-130'

212'-52' 212'-52' 206'--54'

234'-100' 381'-86'

137'--226'

102'-38' 351'-91' 340'-255'

255'-75' 287'-137'

336'-191' 336'-116'

339'-159'

211'-21' 419'-149'

289'-92' 420'-102'

379'-256' 335'-267'

396'-258'

377'-302'

331'-219'

218'-83'

176'-67' 431'-331'

TDD#: WS03-13-10-001 Contract: EP-S3-10-05 Prepared: 4/3/2014 

### Figure 3

On-site and Nearby Wells Baghurst Drive
PA State Plane, NAD83 

#  ́ Legend

& < Observed Release
Well

! 

### A Background Well (no detections)

! 

### A Level II Well

! 

### A Level I Well

Source 1 Domestic Well Completion

Brunswick Fm (Trb)

Lockatong Fm (Trl)

Not Listed 0 1,000 ft Harleysville, Montgomery County, PA 1:12,000

Notes: 1. The plume area shown on the map is based on the analytical data for wells that document an observed release contained in Refs. 7 and 13 of this HRS documentation record. 2. Domestic well data (location, depth, construction, and formation) were obtained from the PAGWIS database cited in Reference 26 of this HRS documentation record. 3. Bedrock geology of Pennsylvania: Pennsylvania Geological Survey, 4th series (compiled in 2001). 1:250,000 scale. Service Layer Credits: Source: Esri, DigitalGlobe, GeoEye, i-cubed, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, swisstopo, and the GIS User Community

Map Area

Postings provide open interval (Mean Sea Level)SD

- Characterization and Containment
Source No.: 1

12 SOURCE DESCRIPTION

2.2 SOURCE CHARACTERIZATION

Number of the source: 1

Source Type of the source: Other

Name and description of the source: Contaminated Ground Water Plume with no identified source

The source, contaminated ground water plume with no identified source, is characterized by analytical results of ground water samples collected from monitoring wells in November 2012 and residential drinking water wells collected in July 2011 as described below an d in Section 3.1.1 of this HRS d ocumentation r ecord. To date, EPA and PADEP have not identified a source for the contaminants present in the ground water. Please refer to the discussion regarding attribution in Section 3.1.1 of this HRS documenta tion record for more detailed information pertaining to
the unknown o rigin of the contaminants.

I n November 2012, ground water samples were collected from monitoring wells located at the site [Ref. 7 , pp. 11,
12 , 77

- 116 ]. Analytical results of the ground water samples collected from the monitoring wells using pumps or
bailers indicated the presence of 1,1,1

- TCA with a maximum concentration of 18,000 μg/L detected in well
BAMW28D ; 1,1

- DCE with a maximum concentration of 2,300 μg/L detected in well BAMW19S ; TCE with a
maximum concentration of 58 μg/L detected in well BAMW28D ; vinyl chloride with a maximum concentration of 2 μg/L detected in well BAMW25D; and 1,4

- dioxane with a maximum concentration of 220 μg/L detected in well
MW19D [Ref. 7 , pp. 21, 57

, 85, 87, 88, 105, 164, 170, 172, and 249 ]

. For the presentation of 2012 analytical results documenting the ground water plume, including comparison to background, see Section 3.1.1 of this HRS
documentation record

.

In July 2011, ground water samples were collected from 1 5 residential drinking water wells , including one common
well [Ref. 12

, pp. 2

- 5 ]. An additional residence was sampled in October 2011 [Ref. 12, p. 8]

. Analytical results of the ground water samples collected from the drinking water wells indicated the presence of 1, 1,1

- TCA with a maximum concentration of 962 μg/L detected in well 1886H; 1,1

- DCE with a maximum concentration of 647 μg/L detected in well 1886H; TCE with a maximum concentration of 9.23 μg/L detected in well 1886H; and 1,4

- dioxane
with a maximum concentration of 69.6 μg/L detected in well 1886H [Ref. 1 3 , pp. 47, 48, and 51 ]. For the presentation of 2011 analytical results documenting the ground water plume, including comparison to background,
see Section 3.1.1 of this H RS documentation record

.

Additional evidence of contamination includes samples collected from wells via hydrosle e ve and passive diffusion bag (PDB) samplers for VOC and 1,4

- dioxane analysis. Analytical results of samples collected from wells using
PDB sa mplers indicated that the highest concentration of 1,1 DCE was 4,400 μg/L

, the highest concentration of 1,1,1

- TCA was 27,000 μg/ L in sample MW19S

- DIS

, and the highest concentration of 1,4

- dioxane was 490 μg/ L in sample MW09

- DIS [ Ref . 7, pp. 88, 89, 184, 18 6].

Ground water samples have been periodically collected at the site by PADEP since 2000 ; however, only the most recent sample results , with respect to applicable background samples, are included in this HRS documentation
record to be most ref lective of current conditions [Ref. 28, pp. 1 and 3]

.

Location of the source, with reference to a map of the site:

The ground water plume is identified by contamination found in the monitoring wells and residential drinking water
wells [ Figure 2 ] . For the purpose of this HRS evaluation , th ese well s represent a minimum of the plume extent. The
site is located in southeastern Pennsylvania and is shown in Figure s 1 and 2 of this HRS documentation record

.SD

- Characterization and Containment
Source No.: 1

13 Containment

Release to ground water:

Analytical results for ground water samples collected from monitoring wells and private drinking water wells
indicate that a release of hazardous substances has occurred to the ground water migration pathway as documented
in Section 3.1.1 of this HRS docum entation record. Based on this evidence of hazardous substance migration , a containment factor value of 10 is assigned for the ground water migration pathway [Ref. 1, p. 51596 , Table 3

- 2 ].SD

- Hazardous Substances
Source No.: 1

14 2.4.1 Hazardous Substances

Ground water samples collected in 2011 and 2012 from monitoring wells and residential drinking water wells
indicate the presence of chlorinated solvents such as 1,1,1

- TCA, 1,1

- DCE, TCE, vinyl chloride

, and 1, 4

- dioxane [ Ref s. 7 , pp. 162

- 298; 1 3 , pp. 1

- 84 ]

. These hazardous substances are not naturally occurring [Refs. 16, p. 1; 17, p. 1]. 1,1,1

- TCA and TCE are man

- made chlorinated solvents that are commonly used as cleaning and degreasing agents, while 1,1

- DCE and vinyl chloride can be degradation breakdown products of either or both 1,1,1

- TCA and
TCE [Refs. 6, p. 48; 30, p. 1 ]. Additionally, 1,4

- dioxane was historically used as a stabilizer for chlorinated solvents, primarily 1,1,1

- TCA. [Ref. 25, p. 1].

These contaminants are not u biquitous and were not detected in ground water samples collected from background wells (BAMW20, BAMW21, BAMW22

, BAMW32S, BAMW32D, and BAMW36S for monitoring wells and 2096H and 2179H for residential drinking water wells) above applicable sample quantitati on limits ( SQL ) [Refs. 7, pp. 209, 225, 227 , 221, 223, and 251 ; 13 , pp. 65

- 71 and 72

- 78 ; 31, p. 1 ; 34, p. 1 ]. For the presentation of analytical results documenting hazardous substances associated with the ground water plume, see Section 3.1. 1 of this HRS
documentation record and Figure 3 for sample locations

.SD

- Hazardous Waste Quantity
Source No.: 1

15 2.4.2 Hazardous Waste Quantity

2.4.2.1.1 Hazardous Constituent Quantity

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 Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) hazardous substances in 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 records and current data available to adequately calculate the total 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 , and hazardous constituent quantity is not scored (NS)

.

Hazardous Constituent Quantity (C) Value: NS

2.4.2.1.2 Hazardous Wastestream Quantity

The hazardous wastestream quantity for Source No. 1 could not be adequately determined according to the HRS requirements; that is, the total mass of all hazardous wast estreams and CERCLA pollutants and contaminants for 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 available to adequately calculate the total mass of all hazardous wastestreams and CERCLA pollutants and contaminants for the source and the associated releases from the source. Therefore, there is insufficient information to adequately calculate or extrapolate the hazardous wastestream quantity for Source No. 1 with reasonable confidence , and hazardous wastestream quantity is
not scored

.

Hazardous Wastestream Quantity (W) Value: NS

2.4.2.1.3 Volume

Based on sampling data of monitoring wells and residential drin king water wells , a contaminated ground water plume with no identified source has been documented

. However, t he vertical and horizontal extents of the ground
water contamination have not been identified. Therefore, for Source No. 1, a value of unknown, but greater than zero has been assigned for the source hazardous waste quantity (HWQ) value for volume



### . The source type is
‘Other ; ’ therefore, the volume value is divided by 2.5 to obtain the assigned value, as shown below [Ref. 1, p.
51591 , Secti on 2.4.2.1.3, Table 2 -5 ].

Dimension of source (yd 3 ) : >0 yd 3 Volume (V) Assigned Value: (>0)/2.5 = >0

2.4.2.1.4 Area

Tier D is not evaluated for source type “other” [Ref. 1, p. 51591, Table 2 -5 , Section 2.4.2.1.3 ].

Area of source (ft 2 ): N/A
Area (A) Assigned Value: 0

2.4.2.1.5 Source Hazardous Waste Quantity Value

The source hazardous waste quantity value for Source 1 is >0 for Tier C
- Volume [Ref. 1, p. 51591 , Section
2.4.2.1.5 ].

Source Hazardous Waste Quantity Value: >0SD

- Summary

16 SITE SUMMARY OF SOURCE DESCRIPTIONS

Source Number Source Hazardous Waste Quantity
Value Containment
Ground Water Surface
Water Air (Gas) Air (Particulate)
1 >0 10 NS NS NS

NS = Not s cored

.GW

- General

17 3.0 GROUND WATER MIGRATION PATHWAY

3.0.1 General Considerations

Aquifer/Stratum 1

Aquifer/Stratum Name : Fractured Bedrock Aquifer S ystem (Brunswick and Lockatong Formations)

The Baghurst Drive site and the surrounding study area are underlain by surficial soils that lie above either the Brunswick or Lockatong Formation [Ref. 6, p. 26]. The overburden soils generally consist of either topsoil or pavement for the upper one

- foot below ground surface (bgs). Weathered bedrock soils underlie the topsoil or pavement a nd are present from 1 foot to approximately 9 feet bgs. The overburden soils are similar in chemical composition to the underlying bedrock. Generally, the upper few feet of bedrock is severely weathered [Refs. 6, pp. 26, 109

- 168; 7, pp. 118

- 155; 11, pp. 52 , 54

- 56; 19, pp. 85

- 139].

The Lockatong Formation, which outcrops in the northeast portion of the site, consists of cyclic gray siltstones, mudstones, and black shale interbedded with less abundant, cyclic red siltstones, mudstones and sandstones. A gray argillite (slightly metamorphosed siltstone) of the Lockatong Formation represents the lowermost stratigraphic unit in the aquifer being evaluated. The Lockatong Formation grades laterally into red beds of the Brunswick Formation.
The formational contact between the Brunswick Formation and the Lockatong Formation is gradational and has historically been placed where red mudstones predominate over the gray. The Brunswick Formation consists predominantly of reddish

– brown shale, mudstones, siltstones, and san dstones. A complex series of diabase sheets and dikes extensively intruded the Triassic sedimentary rocks (i.e., the Brunswick and Lockatong Formations) during the early Jurassic Period. The nearest outcrop of diabasic rocks in relation to the site lies a bout one half mile to the west of the plume. As a result, the sedimentary rocks are slightly contact metamorphosed and sometimes described as argillite [Ref. 6, pp. 25, 26, and 67

- 71; 11, p. 9]. This potential aquifer discontinuity does not affect the

sco ring evaluation because there are no target wells scored within or west of the diabase [Refs. 6, p. 67; and Figure 3 of this HRS documentation record].

In the vicinity of the site, both the Lockatong and Brunswick formations dip to the southwest, causing the Brunswick Formation to thicken toward the southwest and pinch out towards the northeast. Additionally, a nearby fault located just north of the site has caused localized folding of the strata, essentially forming upper and lower
units of the Brunswi ck Formation separated by a layer of the Lockatong Formation [Refs. 6, pp. 67

- 71; 11, p. 9 and 52]. As illustrated on geologic cross

- sections and monitoring well logs prepared for the site, the upper layer of the Brunswick Formation directly underlies th e site in the southern and western portions; the Lockatong Formation underlies the upper Brunswick, and a lower layer of the Brunswick underlies the Lockatong [Refs. 6, pp. 68

- 71 and
115

- 168; 11, p. 52). In the northern and eastern portions of the site, t he upper Brunswick is not present. The Lockatong Formation directly underlies the site with the lower Brunswick underlying the Lockatong Formation [Ref. 11, pp. 52, 54

- 56; 7, pp. 118

- 132].

The fractured, layered sedimentary rocks of the Brunswick and L ockatong Formations form a regional aquifer system that consists of gradational sequences of shale, siltstone, and sandstone, with fluid transport occurring primarily in fractures because of poor primary porosity [Ref. 36, pp. 2 and 3]. This aquifer syst em comprises a series of dipping lithologic units with different hydraulic properties. The ground water system can be visualized as a series of beds with high transmissivities separated by beds with relatively low transmissivities. These beds vary from a few inches to a few feet, and act as a series of alternating aquifers and confining or semi

- confining units that form a leaky, multi

- aquifer system [Ref. 6, p. 26, 28]. Generally, the Lockatong Formation represents a confining or
semi

- confining unit, and t he Brunswick Formation represents a water

- bearing unit. However, there are monitoring and drinking water wells in the area that are screened in the Lockatong Formation [Ref. 26, p. 3] (see also Figure 3 and the monitoring w ell observed release tables in S e ction 3.1.1 of this HRS documentation record).

The direction of ground water flow in the fractured bedrock aquifer system beneath the site is generally west

southwest. Ground water flow in the aquifer system mimics topography and the direction of dip of the bedding planes with a horizontal gradient that averages about 0.11 foot/foot to the west

- southwest and a downward vertical gradient between 0.01 and 0.972. However, consumptive use in the residential neighborhood along Baghurst Drive
has an influenci ng factor on the direction of ground water flow to the south [Ref. 6, pp. 21, 30, 55, 56, 73, and 74].GW

- General

18 Aquifer Interconnection

Ground water movement within the rocks of the Brunswick and Lockatong Formations flows through secondary openings that were d eveloped by external forces, following deposition of the beds. Some of these openings are fractures that parallel the bedding planes. The most important openings are nearly vertical joint planes that cross each other at various angles throughout the beds a nd provide an interconnected series of channels through which ground water can flow [Ref. 14, pp. 11, 12, 15, and 16]. As illustrated by the well logs, fractures are present in both formations throughout the site [Refs. 6, pp. 115

- 68; 7, pp. 54

- 56; and 7, pp. 118

- 132]. The site well logs also illustrate the continuous nature of the Brunswick and Lockatong Formations with no aquifer discontinuity or confining layer, such as an intrusion or clay layer, to separate the two formations [Refs. 6, pp. 115

- 168; 7, pp. 118

- 132; 19, pp. 95

- 139].

Despite differences in transmissivity between the Brunswick and the Lockatong formations reflected in site reports, the material of each formation (i.e. alternating beds of slightly metamorphosed siltstones, mudstones, an d sandstones as described above) is similar enough to result in a hydraulic conductivity for each formation of 10 -6 [Ref. 1, p. 51601, Section 3.1.2.4 Table 3

- 6; Ref. 6, p. 26, 28]. Additionally, as documented in Section 3.1.1 of this HRS
documentation rec ord, hazardous substances associated with this plume were documented in both the Brunswick and the Lockatong Formations at levels significantly above background levels. Therefore, based on the similar hydraulic conductivity of the formations, the presence of numerous fractures within the formations and the documentation of plume

- related contamination in both formations significantly above background levels, the formations are considered a single interconnected hydrologic unit for HRS scoring purposes, i.e., the fra ctured bedrock aquifer system.GW

- Observed Release

19 3.1 LIKELIHOOD OF RELEASE

3.1.1 Observed Release

Aquifer Being Evaluated: Fractured Bedrock System (Brunswick and Lockatong)

An observed release is documented for the Baghurst Drive s ite. Chemical analyses for ground water samples
collected from monitoring wells and residential drinking water wells show the presence of chlorinated solvents s uch as 1,1,1

- TCA, 1,1

- DCE, TCE, vinyl chloride, and 1,4

- dioxane [ Refs. 7, pp. 162

- 298; 1 3 , pp. 1- 84 ].

Direct Observation

The aquifer is not evaluated for observed release by direct observation.

Chemical Analysis

Since 1999, chlorinated solvents have been documented in ground water at Baghurst Drive [Ref. 6 , p. 12 ]. However, only the most recent sample results , with respect to applicable background samples, for each affected well
are included in these results.

In November 2012, ground water samples were collected from monitoring wells at the site [Ref. 7 pp. 77

- 116, 195

- 196, 260

- 262, and 296

- 297 ] . Samples were analyzed for VOCs via EPA Method SW846

- 8260B [ Ref. 7, pp. 162

- 298 ]. T he analytical tests were conducted in accordance with the National Environmental Laboratory Accreditation Conference (NELAC) requirements [Ref. 24, pp. 1

- 3].

The VOC s 1,1,1

- TCA, 1,1

- DCE, TCE, vinyl chloride, and 1,4

- dioxane were detected in the monitoring well samples

at the following maximum concentrations: 1,1,1

- TCA at 18,000 μg/L detected in well BAMW28D ; 1,1

- DCE at 2,300 μg/L detected in well BAMW19S; TCE at 58 μg /L detected in well BAMW28D; vinyl chloride at 2 μg/L detected in well BAMW25D; and 1,4

- dioxane at 220 μg/L detected in well MW19D [Ref. 7 , pp. 21, 57

, 164, 170, 172, and 249]. These hazardous substances were not detected in the background samples above the limits of quantitation (LOQs) [ Ref. 7, pp. 209, 221, 223, 225, 227, 251, 253, and 268 ; 31, p. 1 ].

G round water samples were collected from residential drinking water wells at the site from July to October 2011 [Ref. 12, pp. 1 -8]. Samples were analyz ed for VOCs via EPA Test Method 524.2 and PADEP Bureau of Laboratories (BOL) method BOL6038 for 1,4

- dioxane [ Ref. 13, pp. 1

- 3, 5

- 7, 9

- 11, 13

- 15, 17

- 19, 21

- 23, 25

- 27, 29,
32

- 34, 36

- 38, 40, 43

- 45, 47

- 49, 51, 54

- 56, 58

- 60, 62, 65

- 67, 69, 72

- 74, 76, 79

- 81]. T he analytical tests were conducted in accordance with the NELAC requirements [Ref s . 13

, pp. 3, 7, 11, 15, 19, 23, 27, 30, 34, 38, 41, 45, 49, 52, 56, 60, 63, 67, 74, 77, 81, and 84; 24, pp. 1, 2, and 4 ]. Additionally, EPA’s CLP trace concentration VOC analysi s is based on EPA Test Method 524.2 [Ref. 15, p. 68 ].

The VOCs 1,1,1

- TCA, 1,1

- DCE, TCE, and 1,4

- dioxane were detected in the residential drinking water well samples at the following maximum concentrations in well 1886H: 1,1,1

- TCA at 962 μg/L ; 1,1

- DCE at 647 μg/L ; TCE at
9.23 μg/L ; and 1,4

- dioxane at 69.6 μg/L [Ref. 13 , pp. 47, 48, 50, 51, 53 ]. These hazardous substances were not detected in the background samples above sample quantitation limits (SQLs) [ Ref. 13 , pp. 65

- 71 and 72

- 78 ].

Note about background conditions :

For the site

- specific samples, all background and contaminated samples documenting the observed release in monitoring wells were collected from the hydrologic unit being evaluated ( fractured bedrock of the Br unswick and Lockatong ) [Ref s . 6

, pp. 67

- 71, 115

- 118, 125

- 129, 134

- 158, 164

- 168 ; 7, pp. 125

- 132; 19, pp. 95

- 98, 101

- 103, 110

- 139 ; 33, p. 1]. Monitoring well s ample collection and analysis procedures for the background and release samples

, which were all collected during the same timeframe (November 13 to 20, 2012)

, were identical [Ref. 7

, pp. 77

- 11 4

, 195

- 196, 260

- 262, 296

- 297]

.

Information regarding the exact depth s , well construction, and lithology of the residential drinking water wells being
used to document an observed release is not known

. A vailable information for other domestic wells in the vicinityGW

- Observed Release

20 of the site, particularly toward the south and west where the upper unit of the Brunswick Formation is present

, indicate that the majority of the dom estic wells in this region are completed in the Brunswick Formation

, rang e in depth from approximately 150 to 300 feet bgs

, and are cased to approximately 20

- 40 feet bgs , as show n on Figure 3 of this HRS documentation record [Ref. 26 , pp. 1 -3]. Based on the consistency of this regional data, the residential background and release wells presented in this HRS documentation record are expected to be of similar depth, construction, and lithology.GW

- Observed Release

21 Background Concentrations

Monitoring wells

Sample ID Surface
Elevation (msl) Completed
Well Depth (feet bgs) Screened
Interval ( feet bgs/

m sl * ) Formation Sample
Date Reference(s)

BAMW20 408.89 34 14

- 34/
394.89

- 374.89 Lockatong 11/15/12 6, pp. 16, 70, 156; 7, pp. 99, 261
BAMW21 360.39 4 0 20

- 40 /
340.39

- 320.39 Lockatong 11/14/12 6, pp. 16, 157; 7, pp. 83, 260
BAMW22 383. 2 6 41 21

- 4 1 /
362. 26-
342.26 Lockatong 11/15/12 6, pp. 16, 70, 158; 7, pp. 100, 261
BAMW32S 409.3 5 61 45

- 60 /
364.3 5-
349.3 5 Lockatong/
Brunswick 11/15/12 7, pp. 97, 260; 19. pp. 28, 110

- 11 2 ; 33, p. 1
BAMW32D 409.35 100 79

- 99 /
330.35

- 310.35 Brunswick 11/15/12 7, pp. 98, 261; 19, pp. 28, 113

- 116; 33, p. 1
BAMW36S 397.30 375 140

- 170 /
257.3

- 227.30 Brunswick 11/16/12 7, pp. 107,
125

- 132, 262; 11, p. 55 bgs
– below ground surface
msl
– mean sea level * msl screened interval determined by subtracting the depth in feet bgs from the surface elevation

Sample ID Hazardous Substance Concentration (μg/L) LOQ 1 (μg/L) Reference(s)

BA MW20 1,1,1

- TCA ND 0.5 7 , p. 225 1,1

- DCE ND 0.5
TCE ND 0.5 Vinyl Chloride ND 0.5 1,4

- Dioxane ND 2
BA MW 2 1 1,1,1

- TCA ND 0.5 7 , p. 209 1,1

- DCE ND 0.5
TCE ND 0.5 Vinyl Chloride ND 0.5 1,4

- Dioxane ND 2
BAMW22 1,1,1

- TCA 0.3J 0.5 7 , p. 227 1,1

- DCE ND 0.5
TCE ND 0.5 Vinyl Chloride ND 0.5 1,4

- Dioxane ND 2
BAMW32S 1,1,1

- TCA ND 0.5 7, p. 221 1,1

- DCE ND 0.5
TCE ND 0.5 Vinyl Chloride ND 0.5 1,4

- Dioxane ND 2GW

- Observed Release

22 Background Concentrations (continued)

Monitoring well s (continued)

Sample ID Hazardous Substance Concentration (μg/L) LOQ 1 (μg/L) Reference(s)

BAMW32D 1,1,1

- TCA ND 0.5 7, p. 223 1,1

- DCE ND 0.5
TCE 0.2J 0.5 Vinyl Chloride ND 0.5 1,4

- Dioxane ND 2
BAMW36S 1,1,1

- TCA ND 0.5 7, p. 251 1,1

- DCE ND 0.5
TCE ND 0.5 Vinyl Chloride ND 0.5 1,4

- Dioxane ND 2

1 The LOQ is equivalent to the HRS

- defined Sample Quantitation Limit ( SQL ) , i.e., the quantity of a substance that can reasonably be quantified given the limits of detection for the methods of analysis and sample characteristics that may affect quantitation such as dilution or concentration [Refs. 1, p. 51586, 51589; 31, p. 1].
J - estimated value
– The result is ≥ the Method Detection Limit (MDL) and < the Limit of Quantitation (LOQ) (Ref. 7, p. 263). Based on the definition of the qualifier, no bias is associated w ith this result. Therefore, the analyte’s background concentration equals the SQL (Ref. 1, p. 51589, Table 2 -3 ; 32, p. 8 ).

Background Concentrations

Residential Wells

Sample ID Sample Date Hazardous Substance Concentration (μg/L) SQL 1 (μg/L) Reference(s)

2096H 7/6/11 1,1,1

- TCA ND 0.25 12, pp. 1

- 2; 13, pp. 65

- 71

, 165, and 186 ; 34, p. 1 1,1

- DCE ND 0.25
TCE ND 0.25 Vinyl Chloride ND 0.25 1,4

- Dioxane ND 5
2179H 7/6/11 1,1,1

- TCA ND 0.25 12, p. 3 ; 13, pp. 72

- 78

, 167, and 187 ; 34, p. 1 1,1

- DCE ND 0.25
TCE ND 0.25 Vinyl Chloride ND 0.25 1,4

- Dioxane ND 5

1 For the residential well data, SQL is defined as being equivalent to the HRS

- defined SQL , i.e., the quantity of a substance that can reasonably be quantified given the limits of detection for the methods of analysis and sample characteristics that may affect quantitation such as dilution or concentration [Refs. 1, p. 51586, 51589; 3 4 , p. 1].GW

- Observed Release

23 Contaminated Samples

Monitoring wells

Sample ID Surface
Elevation (msl) Completed
Well Depth (feet bgs) Screened
Interval ( feet bgs/
msl ) * Formation Sample
Date Reference(s)

BAMW5S 302.30 100 69

- 99/
233.30

- 203.30 Brunswick 11/13/12 6, pp. 16, 70, 115, 116; 7, pp. 79, 195
BAMW5D 302.45 149 119

- 149/
183.45

- 1 5 3.45 Brunswick 11/13/12 6, pp. 16, 70, 117, 118; 7, pp. 93, 195
BAMW7S 294.55 118 101

- 116 /
193.55

- 178.55 Brunswick 11/13/12 6, pp. 16, 71, 125, 126; 7, pp. 92, 195
BAMW7D 294.55 203 125

- 140 /
169.55

- 15 4 .55 Brunswick 11/13/12 6, pp. 16, 71, 127

- 129; 7, pp. 91, 195
BAMW9 311.39 101 60

- 100 /
251.39

- 211.39 Brunswick/ Lockatong 11/13/12 6, pp. 16, 70, 134, 135; 7, pp. 90, 195
BAMW10S 288.74 102 72

- 102 /
216.74

- 186.74 Brunswick 11/14/12 6, pp. 16, 68, 71, 136, 137; 7, pp. 95, 260
BAMW10D 288.87 132 112

- 132 /
176.87

- 156.87 Brunswick/ Lockatong 11/14/12 6, pp. 16, 68, 71, 138, 139; 7, pp. 94, 260
BAMW11S 301.46 15 5

- 15 /
296.46

- 286.46 Lockatong 11/20/12 6, pp. 16, 68, 69,70, 140; 7, pp. 113, 296
BAMW11D 300.74 42 20

- 40 /
280.74

- 260.74 Lockatong 11/20/12 6, pp. 16, 68, 69, 70, 141; 7, pp. 114, 296
BAMW12S 332.2 55 35

- 55 /
297.2

- 277.2 Brunswick 11/19/12 6, pp. 16, 69, 142; 7, pp. 111,
296
BAMW12D 332.2 110 90

- 110 /
242.2

- 222.2 Lockatong 11/19/12 6, pp. 16, 69, 143, 144; 7, pp. 110, 296
BAMW13 357.23 25 15

- 25 /
342.23

- 332.23 Lockatong 11/15/12 6, pp. 16, 70, 145; 7, pp. 96,
260
BAMW14 327.92 25 15

- 25 /
312.92

- 302.92 Lockatong 11/19/12 6, pp. 16, 146; 7, pp. 112, 296; 33, p. 1
BAMW15S 277.71 70 50

- 70 /
227.71

- 207.71 Brunswick 11/14/12 6, pp. 16, 69, 147, 148; 7, pp. 80, 261
BAMW15D 277.71 103 81

- 103 /
196.71

- 174.71 Brunswick/ Lockatong 11/14/12 6, pp. 16, 69, 149, 150; 7, pp. 78, 261
BAMW16 350.85 32 12

- 32 /
338.85

- 318.85 Brunswick/ Lockatong 11/19/12 6, pp. 16, 71, 151; 7, pp. 109,
296
BAMW17 359.04 25 15

- 25 /
344.04

- 334.04 Lockatong 11/14/12 6, pp. 16, 71 152; 7, pp. 82,
260
BAMW18 359.04 20 10

- 20 /
349.04

- 339.04 Lockatong 11/14/12 6, pp. 16, 153; 7, pp. 84, 260; 33, p. 1
BAMW19S 321.16 52 16

- 36 /
305.16

- 285.15 Brunswick 11/13/12 6, pp. 16, 70, 154; 7, pp. 88,
195
BAMW19D 321.16 52 42

- 52 /
297.16

- 269.16 Lockatong 11/13/12 6, pp. 16, 70, 155; 7, pp. 87,
195
BAMW25S 292.79 144 124

- 144 /
168.79

- 148.79 Brunswick 11/16/12 6, pp. 16, 70, 71, 164, 165; 7, pp. 104, 262
BAMW25D 292.84 188 168

- 188 /
124.84

- 104.84 Lockatong 11/16/12 6, pp. 16, 70, 71 166, 167, 168; 7, pp. 105, 262GW

- Observed Release

24 Contaminated Samples (continued)

Monitoring wells ( c ontinued)

Sample ID Surface
Elevation (msl) Completed
Well Depth (feet bgs) Screened
Interval ( feet bgs/
msl ) * Formation Sample
Date Reference(s)

BAMW28S 338.85 31 20

- 30/
318.85

- 308.85 Brunswick 11/13/12 7, pp. 86, 195; 19, pp. 95

- 96; 33, p. 1
BAMW28D 338.85 41 36

- 41/
302.85

- 297.85 Lockatong 11/13/12 7, pp. 85, 195; 19 , pp. 97, 98 ; 33, p. 1
BAMW30 359.29 70 60

- 70/
299.29

- 289.29 Lockatong 11/14/12 7, pp. 81, 260; 19, pp. 101

- 103; 33, p. 1
BAMW33S 294.01 143 121

- 141/
173.01

- 153.01 Brunswick 11/15/12 7, pp. 103, 261; 19, pp. 117

- 121; 33, p. 1
BAMW33D 294.01 158 147

- 157/
147.01

- 137.01 Brunswick/ Lockatong 11/16/12 7, pp. 102, 261; 19, pp. 122

- 127; 33, p. 1
BAMW34S 234.54 146 123

- 143/
111.54

- 91.54 Brunswick 11/20/12 7, pp. 115, 296; 19, pp. 128

- 132; 33, p. 1
BAMW34D 234.54 203 193

- 203/
41.54

- 31.54 Brunswick 11/20/12 7, pp. 116, 297; 19, pp. 133

- 139; 33, p. 1 bgs
– below ground surface
msl
– mean sea level * msl screened interval determined by subtracting the depth in feet bgs from the surface elevation

Sample ID Hazardous Substance Concentration (μg/L) LOQ 1 (μg/L) Reference(s)

BA MW5S 1,1,1

- TCA 10 0.5 7

, p. 176 1,1

- DCE 18 0.5 1,4

- Dioxane 22 2
BA MW5D 1,1,1

- TCA 94 10 7

, p. 168 1,1

- DCE 29 10
TCE 0.7 0.5 1,4

- Dioxane 6.4 4
BA MW7S 1,1,1

- TCA 1,800 250 7

, p. 180 1,1

- DCE 1,200 25 1,4

- Dioxane 83 20
BAMW7D 1,1,1

- TCA 2,500 250 7

, p. 17 8 1,1

- DCE 1,500 250 1,4

- Dioxane 90 10
BAMW9 1,1,1

- TCA 4,400 500 7

, p. 174 1,1

- DCE 990 50 1,4

- Dioxane 210 20
BA MW10S 1,1,1

- TCA 3,000 100 7

, p. 213 1,1

- DCE 1,900 100
TCE 27 10 1,4

- Dioxane 130 40
BA MW10D 1,1,1

- TCA 390 25 7

, p. 215 1,1

- DCE 290 25
TCE 16 2.5 1,4

- Dioxane 47 20GW

- Observed Release

25 Contaminated Samples (continued)

Monitoring wells (Continued)

Sample ID Hazardous Substance Concentration (μg/L) LOQ 1 (μg/L) Reference(s)

BAMW11S 1,1,1

- TCA 160 10 7, p. 284 1,1

- DCE 20 0.5 1,4

- Dioxane 4.9 2
BAMW11D 1,1,1

- TCA 700 25 7, p. 286 1,1

- DCE 79 2.5 1,4

- Dioxane 11 4
BAMW12S 1,1,1

- TCA 1,900 50 7, p. 274 1,1

- DCE 820 50
TCE 16 5 1,4

- Dioxane 93 10
BAMW15S 1,1,1

- TCA 1,900 100 7, p. 241 1,1

- DCE 1,200 100
TCE 15 10 1,4

- Dioxane 110 40
BAMW15D 1,1,1

- TCA 63 5 7, p. 243 1,1

- DCE 59 5
TCE 4.1 0.5 1,4

- Dioxane 9.1 2
BAMW16 1,1,1

- TCA 1,800 50 7, p. 270 1,1

- DCE 170 5 1,4

- Dioxane 37 10
BAMW17 1,1,1

- TCA 220 10 7, p. 205 1,1

- DCE 49 10
TCE 6.2 0.5 1,4

- Dioxane 7.6 2
BAMW19S 1,1,1

- TCA 15,000 1,000 7, p.172 1,1

- DCE 2,300 100 1,4

- Dioxane 180 40
BAMW19D 1,1,1

- TCA 15,000 1,000 7, p. 170 1,1

- DCE 1,300 100 1,4

- Dioxane 220 40
BAMW25S 1,1,1

- TCA 720 25 7, p. 247 1,1

- DCE 270 25 1,4

- Dioxane 31 4
BAMW25D 1,1,1

- TCA 140 10 7, p. 249 1,1

- DCE 470 10
TCE 4.6 1 Vinyl Chloride 2 1 1,4

- Dioxane 23 2
BAMW28D 1,1,1

- TCA 18,000 1,000 7, p. 164 1,1

- DCE 1,000 100 1,4

- Dioxane 180 40
BAMW33S 1,1,1

- TCA 5,000 250 7, p. 235 1,1

- DCE 1,800 250 1,4

- Dioxane 110 10
BAMW33D 1,1,1

- TCA 3.3 0.5 7, p. 239 1,1

- DCE 1.3 0.5GW

- Observed Release

26 Contaminated Samples (continued)

Monitoring wells (Continued)

Sample ID Hazardous Substance Concentration (μg/L) LOQ 1 (μg/L) Reference(s)

BAMW34S 1,1,1

- TCA 410 10 7, p. 288 1,1

- DCE 220 10
TCE 2.6 1 1,4

- Dioxane 24 4
BAMW34D 1,1,1

- TCA 500 25 7, p. 290 1,1

- DCE 290 25
TCE 3.2 1 1,4

- Dioxane 29 4

1 The LOQ is equivalent to the HRS

- defined SQL , i.e., the quantity of a substance that can reasonably be quantified given the limits of detection for the methods of analysis and sample characteristics that may affect quantitation such as dilution or concentration [Refs. 1, p. 51586, 51589; 31, p. 1].

Contaminated Samples (continued)

Residential wells

Sample ID Sample Date Hazardous Substance Concentration (μg/L) SQL 1 (μg/L) Reference(s)

1747H 7/ 6 /11 1,1,1

- TCA 217 2.5 12 , p. 3 ; 13 , pp. 5, 6, 8 , 109, 110, and 174 ; 34, p. 1 1,1

- DCE 99.4 2.5
TCE 1.47 0.25
1787H 7/27/11 1,1,1

- TCA 244 2.5 12, p. 5 ; 13 , pp. 25, 26, 28, 29, 31

, 97, 99, 192 ; 34, p. 1 1,1

- DCE 155 2.5
TCE 1.67 0.25 1,4

- Dioxane 15.9 5
1836H 7/14/11 1,1,1

- TCA 551 2.5 12, p. 4 ; 13 , pp. 91 and 93 ; 34, p. 1 1,1

- DCE 338 2.5
TCE 3.59 0.25
1886H 7/6/11 1,1,1

- TCA 962 25 12, p. 2 ; 13 , pp. 47, 48, 50, 51, 53 , 105, 163, and 185 ; 34, p. 1 1,1

- DCE 647 25
TCE 9.23 0.25 1,4

- Dioxane 69.6 5
1898H 10 / 12 /11 1,1,1

- TCA 190 2.5 12, p. 8 ; 13 , pp. 54

- 57 , 101,
and 103 ; 34, p. 1 1,1

- DCE 123 2.5
TCE 0.833 0.25
1926H 7/6/11 1,1,1

- TCA 43.9 0.25 12, p. 3 ; 13 , pp. 59, 61 , and
169 ; 34, p. 1 1,1

- DCE 4. 1 7 0.25
1744B ( Common
W ell ) 7/6/11 1,1,1

- TCA 44.8 0.25 12 , p. 3 ; 13 , pp. 79, 80, 82

- 84 , 176, and 189; 21, pp. 1

- 2 ; 34, p. 1 1,1

- DCE 31.8 0.25
TCE 0.368 0.25 1,4

- Dioxane 5.79 5
1746B 7/7/11 1,1,1

- TCA 365 2.5 12

, p

. 4 ; 13 , pp. 1, 2, 4 , 113,
and 115 ; 34, p. 1 1,1

- DCE 232 2.5
TCE 2.54 0.25
1760B 7/6/11 1,1,1

- TCA 370 2.5 12, p. 3 , 13 , pp. 9, 10, 12

, 107and 171 ; 34, p. 1 1,1

- DCE 234 2.5
TCE 2.56 0.25GW

- Observed Release

27 Sample ID Sample Date Hazardous Substance Concentration (μg/L) SQL (μg/L) Reference(s)

1767B 7/14/11 1,1,1

- TCA 335 2.5 12, p. 4 ; 13, pp. 13, 14, 16, 119, and 121; 34, p. 1 1,1

- DCE 236 2.5
TCE 2.22 0.25
1775B 7/14/11 1,1,1

- TCA 399 2.5 12, p. 4 ; 13, pp. 17, 18, 20, 87, and 89; 34, p. 1 1,1

- DCE 265 2.5
TCE 2.52 0.25
1780B 7/7/11 1,1,1

- TCA 16.6 0.25 12, p. 4 ; 13, pp. 21, 22, 24, and 117; 28. p. 1; 34, p. 1 1,1

- DCE 10.2 0.25
1800B 7/6/11 1,1,1

- TCA 101 2.5 12, p. 2 ; 13, pp. 32, 33, 35, 123, and 161; 34, p. 1 TCE 0.723 0.25
1810B 7/6/11 1,1,1

- TCA 561 2.5 12, p. 2 ; 13, pp. 37, 39, 40, 42, 85 159, and 184; 34, p. 1 1,1

- DCE 319 2.5 1,4

- Dioxane 32.2 5

1 For the residential well data, SQL is defined as being equivalent to the HRS

- defined SQL , i.e., the quantity of a substance that can reasonably be quantified given the limits of detection for the methods of analysis and sample characteristics that may affect quantitation such as dilution or
concentration [Refs. 1, p. 51586, 51589; 3 4 , p. 1].GW

- Observed Release

28 Attribution:

The hazardous substances associated with the site are not naturally occurring [Refs. 16, p. 1; 17, p. 1]. 1,1,1

- TCA
and TCE are man

- made chlorinated solvents that are commonly used as cleaning and degreasing agents, while 1,1

- DCE and vinyl c hloride can be degradation breakdown products of either or both 1,1,1

- TCA and TCE [Refs. 6, p. 48; 16 , p. 1 ; 1 7

, p. 1 ; 30, p. 1 ]. Additionally, 1,4

- dioxane was historically used as a stabilizer for chlorinated solvents, primarily 1,1,1

- TCA [Ref. 25, p. 1 ].

In April 2001, PADEP contracted Foster Wheeler to conduct a source investigation for the VOCs detected in the residential wells. The source investigation focused on a 29

- acre farm property located a t on Hendricks Road. The
invest igation consisted of ad vancing 225 soil borings, collecting 363 soil samples, installing 21 bedrock monitoring wells, collecting ground water samples from the monitoring wells during four separate sampling events conducted between July 2001 and January 2003, and the collection o f 42 surface water samples from seeps and stream water during three separate sampling events conducted in February, March

- April, and November 2002 [Ref 6, p p. 7, 9, 22, 23, 38, and 55 ). Analytical results of the source investigation indicate d the presence of chlorinated VOCs (primarily 1,1,1

- TCA, 1,1

- DCE, 1,1

- DCA, vinyl chloride

, and TCE) in soil, ground water and surface water. The report
concluded that t he core area of the highest chlorinated VOC concentrations in ground water (based on spat ial concentrations) was located on the f arm p roperty on Hendricks Road and ha d migrated approximately 800 feet downgradient in a west

- southwest direction; however, the consumptive use in the Baghurst Drive residential neighborhood has a n influence on the d irection of ground water flow to the south [Ref. 6, pp. 55

, 56 , 73, and 74 ].

Of the 225 soil borings advanced and 363 soil samples collected on the farm prop e rty, thirty

- three contained 1,1,1

- TCA (maximum concentration of 180 μg/kg), four contained 1,1 -D CE (maximum concentration of 18 μg/kg), two contained 1,1

- DCA (maximum concentration of 10 μg/kg, and seven contained TCE (maximum concentration of 24 μg/kg) [Ref. 6, pp. 40, 103, 104

, 421

- 422, 430

- 431

, 436, 451, 455

- 456, 462, 465

- 469, 472

- 474, and 477

- 478 ]. Due
to the relatively low levels of contaminants detected and the small number of samples containing contaminants, EPA
could not confirm that the soil contaminatio n detected between 2001 and 2002 on the farm property is contributing

to

, or is a signifi cant contributor of, the ground water contamination being scored

.

Over the past decade during numerous rounds of sampling events, affected residents have alleged to PADEP that dumping of waste had occurred on the farm property [Ref. 20]. PADEP conducted several investigative interviews with the farm property owner and nearby residents; however, the agency was unsuccessful in documenting that waste was in fact dumped on the property and in identifying potential responsible parties [Ref. 20]. The farm

pro perty owners have maintained that, to their knowledge, waste was never dumped on the property [Ref. 20]. The
site is located in a rural area with no discernible industrial or commercial facilities within a half

- mile radius of the site [Refs. 4 and 20].

N o other potential sources for the ground water contamination comprising the plume have been identified. A search
of t he Envirofacts ® database identified nine facilities with National Pollution Discharge Elimination System (NPDES) permits within approximat ely 1 mile of the site reference point. Six of these facilities are identified as individual private residences

, a subdivision , or dwelling other than apartments; two are sewage treatment facilities; and one is a bulk fuel storage facility

. The NPDES permits for all nine facilities are for discharge s from non

Publicly Owned Treatment Works ( POTW ) systems

. No violations were noted at any of the facilities. One Toxics
Release Inventory (TRI) facility was i dentified. This facility is listed as being a metal fabricator that transports chromium compounds offsite for recycling. This facility is located more than 1.5 miles from the site and is not expected to be the source or contribute to the source of contamination at the site [Ref

. 29, pp. 1- 46 ].

Hazardous Substances Released:

1,1,1 -T richloroethane ( 1,1,1

- TCA ) 1,1

- Dichlorothene (1,1

- DCE) Trichloroethylene (TCE) Vinyl Chloride 1,4

- Dioxane

================================================================================== Ground Water Observed Release Factor Value: 550GW

- Waste Characteristics

29 3.2 WASTE CHARACTERISTICS

3.2.1 Toxicity/Mobility

Hazardous Substance Source
Numbers Toxicity
Factor Value Mobility
Factor Value Toxicity/ Mobility Reference

1,1,1

- TCA 1, OR 1 1.0 1 2, p. 1 0 1,1

- DCE 1, OR 10 1.0 10 2, p. 4

T CE 1, OR 1,000 1.0 1,000 2, p. 10 Vinyl Chloride 1, OR 10,000 1 .0 10,000 2, p. 1 0 1,4

- Dioxane 1, OR 100 1 .0 100 2, p. 5
OR = Observed Release

3.2.2 Hazardous Waste Quantity

Source Number Source Hazardous Waste Quantity (HWQ) Value ( Ref. 1 Section 2.4.2.1.5) Is source hazardous constituent quantity data complete? (yes/no)
1 >0 No

Sum of Values: >0

The sum corresponds to a hazardous waste quantity factor value of 1 in Table 2

- 6 of the HRS [Ref. 1, p. 51591]. However, based on the fact that the hazardous constituent quantity is not adequately determined (see Section
2.4.2.1.1 of this HRS documentatio n record) and targets are subject to Level I concentrations (see Section 3.3.2.3 of
this HRS documentation record ), a hazardous waste quantity factor value of 100 is assigned if it is greater than the hazardous waste quantity value from Table 2

- 6 (i.e., 1) [Ref. 1, pp 51591

- 51592 , Section 2.4.2.2 ]. Therefore, a hazardous waste quantity factor value of 100 is assigne d for the ground water pathway [ Ref. 1, p p 51591

- 51592

, Section 2.4.2.2 ].

3.2.3 Waste Characteristics Factor Category Value

Vinyl c hloride corresponds to the toxicity/mobility factor value of 10,000, as shown previously (see Section 3.2.1 of
this HRS d ocumentation record ).

Toxicity/Mobility Factor Value (10,000) x Hazardous Waste Quantity Factor Value (100): 1 x 10 6

The product (1 x 10 6 ) corresponds to a Waste Characteristics Factor Category Value of 32 in Table 2

- 7 of the HRS [Ref. 1, p. 51592].

=========================================================== == ===================== Hazardous Waste Quantity Factor Value: 100 Waste Characteristics Factor Category Value: 32GW

- Targets/Ne arest Well

30 3.3 TARGETS

In 1999, PADEP began supplying bottled water and connected carbon filtration systems to 27 residences in the vicinity of the site [Ref. 10 , p. 2]. However, because they are sufficient to score the site, for the purpose of this HRS documentation record, th e target population s being evaluated are the persons who obtain drinking water from the 14 residential drinking water wells that were sampled between July and October 2011 that contain contaminants
attributable to the site [Ref. 12, pp. 1 -8]

. Twelve of th e wells, including one common well that supplies drinking
water to 1 0 residences , contained contaminants attributable to the site at concentrations exceeding applicable benchmarks as presented in Section 3. 3 .2.2 of this HRS documentation record [Ref. 2 1

, pp. 1 -2].

The residents who reside at the homes with the wells that are being used to score the site are currently being provided with bottled water for drinking purposes. T he wells being used to score the site are also equipped with treatment systems. The provided bottled water and treatment systems are a direct result of site related contaminants and are provided by PADEP under its interim Response Action for the site [Ref. 28, pp. 1

- 3]

.

3.3.1 Nearest Well

Because actual contamination at Level I concentrations has been documented, a nearest well factor value of 50 is assigned [Ref. 1, pp. 51602, 51603, Section 3.3.1 ].

================================================================================== Nearest Well Factor Value: 50GW

- Population/Level I

31 3.3.2 Population

3. 3.2.1 Level of Contamination
3.3.2.2 Level I Contamination

Sample Substance Concentration (μg/L) Benchmark Concentration * (μg/L) Benchmark Type * Reference(s)

1747H 1,1,1

- TCA 217 200 MCL 2, p. 2 5 ; 13, p. 5 1,1

- DCE 99.4 7 MCL 2, p. 18 ; 13, p. 6
TCE 1.47 1 CRSC 2, p. 25 ; 13, p. 5
1787H 1,1,1

- TCA 244 200 MCL 2, p. 25 ; 13, p. 25 1,1

- DCE 155 7 MCL 2, p. 18 ; 13, p. 26
TCE 1.67 1 CRSC 2, p. 25 ; 13, p. 26 1,4

- Dioxane 15.9 0.6 CRSC 2, p. 19; 13, p. 29
1836H 1,1,1

- TCA 551 200 MCL 2, p. 2 5 ; 13, p. 93 1,1

- DCE 338 7 MCL 2, p. 18 ; 13, p. 93
TCE 3.52 9 1 CRSC 2, p. 25 ; 13, p. 91
1886H 1,1,1

- TCA 962 200 MCL 2, p. 25 ; 13, p. 47 1,1

- DCE 647 7 MCL 2, p. 18 ; 13, p. 48
TCE 9.23 1 CRSC 2, p. 25 ; 13, p. 47 1,4

- Dioxane 69.6 0.6 CRSC 2, p. 19; 13, p. 51
1898H 1,1,

- DCE 123 7 MCL 2, p. 18 ; 13, p. 56
Common Well 1,1

- DCE 31.8 7 MCL 2, p. 18 ; 13, p. 80 1,4

- Dioxane 5.79 0.6 CRSC 2, p. 19; 13, p. 83
1746B 1,1,1

- TCA 365 200 MCL 2, p. 25 ; 13, p. 2 1,1

- DCE 232 7 MCL 2, p. 18 ; 13. p. 2
TCE 2.54 1 CRSC 2, p. 25 ; 13, p. 1
1760B 1,1,1

- TCA 370 200 MCL 2, p. 25 ; 13, p. 10 1,1

- DCE 234 7 MCL 2, p. 18 ; 13, p. 10
TCE 2.56 1 CRSC 2, p. 25 ; 13, p. 9
1767B 1,1,1

- TCA 335 200 MCL 2, p. 25 ; 13, p. 14 1,1

- DCE 236 7 MCL 2, p. 18 ; 13, p. 14
TCE 2.22 1 CRSC 2, p. 25 ; 13, p. 13
1775B 1,1,1

- TCA 399 200 MCL 2, p. 25 ; 13, p. 18 1,1

- DCE 265 7 MCL 2, p. 18 ; 13, p. 18
TCE 2.52 1 CRSC 2, p. 25 ; 13, p. 17
1780B 1,1

- DCE 10.2 7 MCL 2, p. 18 ; 13, p. 21
1810B 1,1,1

- TCA 561 200 MCL 2, p. 25 ; 13, p. 37 1,1

- DCE 319 7 MCL 2, p. 18 ; 13, p. 37 1,4

- Dioxane 32.2 0.6 CRSC 2, p. 19; 13, p. 40 * Maximum Contaminant Level/Maximum Contaminant Level Goal (MCL/MCLG) , Reference Dose Screen Concentration

(RfD) , and Cancer Risk Screen Concentration (CRSC) a re used as benchmarks for 1,1,1

- TCA, 1,1

- DCE, TCE , and 1,4

- dioxane [Ref. 1, p. 51593 , Section 2.5.2 ; 2

, pp. 18, 19, 25, and 43 ]. The lowest applicable benchmark is listed and used for determination of the level of actual contamination at each sampling location [Ref . 1, pp. 51592

- 51593, Sections 2.5.1 and 2.5.2]

.GW

- Population/Level I

32 Residential Well Location Population Served Reference(s)
1747H 2.5 3 23, p. 1 ; 35, p. 1
1787H 4 23, p. 1 ; 35, p. 1
1836H 5 23, p. 1 ; 35, p. 1
1886H 2 23, p. 1 ; 35, p. 1
1898H 2 23, p. 1 ; 35, p. 1 1744H ( Common Well ) 25.64 21, pp. 1, 2; 23, p. 1 ; 35, p. 1
1746B 2 23, p. 1 ; 35, p. 1
1760B 3 23, p. 1 ; 35, p. 1
1767B 0 23, p. 1 ; 35, p. 1
1775B 2 23, p. 1 ; 35, p. 1
1780B 4 23, p. 1 ; 35, p. 1
1810B 2 23, p. 1 ; 35, p. 1 Total Population 54.17

As shown in the table s above, 11 residential drinking water wells , including one common well that supplies drinking

water to 10 residences

, are subject to Level I concentrations . Several attempts were made to contact the residences
to obtain an accurate count of person s per household. An accurate persons per household count was obtained for 13 of the 21 residences (11 individual domestic well locations and the 10 residences supplied by the common well) with wells containing contaminant observed release concentrations above health

- based benchmarks . The remaining eight residences could not be reached or did not have an active listed phone number; therefore, the county average of
2.5 3 person s per household for Montgomery County as currently reporte d by the U.S. Census Bureau was used to determine the population at those residences. The total population served by drinking water from points of withdrawal subject to Level I concentration s is 54.17 [ Ref. 1, p. 51603, Section 3.3.2.2; 21, pp. 1, 2; 23

, p. 1 ; 35, p. 1]. This population is multiplied by 10 to determine the Level I concentrations factor value, as shown below [Ref. 1, p. 51603, Section 3.3.2.2].

================================================================================== Total Level I Population: 54.1 7
Level I Concentration Factor Value: 52.92 x 10 = 541.70 ( Ref. 1, p. 51603, Section 3.3.2.2 )GW

- Level II/Potential/Resources/Wellhead Protection

33 3.3.2.3 Level II Concentrations

In addition to the drinking water wells subject to Level I concentrations, there are two separate residential wells subject to Level II concentrations (i.e., below all applicable benchmarks), as follows:

Sample Substance Concentration (μg/L) Reference(s)
1926H 1,1,1

- TCA 43.9 13 , p. 59 1,1

- DCE 4. 1 7 13 , p. 59
1800B 1,1,1

- TCA 101 13 , p. 33
TCE 0.723 13 , p. 32

As shown in the table above, two single

- household residential wells are subject to Level II concentrations ; however, currently, the residence from which sample 1800B was collected is not used as a permanent residence. One person currently resides at sample location 1926H. Therefore the total population served by drinking water from points of withdrawal subjec t to Level I I concentrations is 1 [ Ref. 1, p. 51603, Section 3.3.2.3; 35, p. 1 ] . This population is assigned as the Level II concentrations factor value, as shown below [Ref. 1, p. 51603, Section 3.3.2.3]

================================================ ================================== Population Served by Level II Wells: 1
Level II Concentrations Factor Value: 1 [Ref. 1, p. 51603 , Section 3.3.2.3 ]

3.3.2.4 Potential Contamination

Since Level I and Level II concentrations result in a maximum score of 100.00 for the ground water migration pathway, the Potential Contamination Factor Value was not scored.

Potential Contamination Factor Value: NS

3.3.3 Resources

Since Level I and Level II concentrations result in a maximum score of 100.00 f or the ground water migration pathway, the Resources Factor Value was not scored.

================================================================================== Resources Factor Value: NS

3.3.4 Wellhead Protection Area

Since Level I and Level II concentrations result in a maximum score of 100.00 for the ground water migration pathway, the Wellhead Protection Area Factor Value was not scored.

================================================================================== Wellhead Protection Area Factor Value: NS