H RS DOCUMENTATION RECORD

– REVIEW COVER SHEET

Site Name: Sauer Dump

EPA ID No.: MDD981038334

Contact Persons

Site Contact: Lorie Baker, Site Assessment Manager (3HS12) U.S. Environmental Protection Agency (EPA) Region 3

1650 Arch Street Philadelphia, PA 19103-2029 (215) 814-3355 baker.lorie@epa.gov

Pathways, Components, or Threats Not Scored

Ground Water Migration Pathway

The ground water pathway was not scored. The surface w ater pathway was sufficient to list the site.

Soil Exposure Pathway

The soil exposure pathway was not scored. The surface water pathway was sufficient to list the site.

Air Migration Pathway

The air migration pathway was not scored. The surface water pathway was sufficient to list the site.

### 1 HRS DOCUMENTATION RECORD

Date Completed: June 30, 2010

Date Revised: March 2012

Site Name: Sauer Dump

EPA Region: 3

Street Address of Site*: 4225 Lynhurst Road

Dundalk , Maryla nd 21222

City, County and State: Dundalk, Baltimore County, Maryland

General Location in the State: In the eastern portion of Maryland ( shown on Figure 1 of this documentation record; Ref. 4)

Topographic Map: Middle River, Maryland Q uadrangle, 1969

, photorevised 1985

Latitude: 39.270267 N Longitude: 76.4527100 W (Ref. 19; Ref. 35 )

* The street address, coordinates, and contaminant locations presented in this Hazard Ranking System ( HRS ) documentation record identify the general area in which the site is located. They represent one or more locations U.S. Environmental Protection Agency ( EPA ) considers to be part of the site based on the screening information EPA used to evaluate the site for National Priorities List ( NPL ) listing. EPA lists national priorities among the known "releases or threatened releases" of hazardous substances; thus, the focus is on the release, not precisely delineated boundaries. A site is defined as where a hazardous substance has been "deposited, stored, placed, or otherwise come to be located." Generally, HRS scoring and the subsequent listing of a release merely represent the initial determination that a certain area may need to be addressed under the Comprehensive Environmental Response, Compensation, and Liabili ty Act. Accordingly, EPA contemplates that the preliminary description of property 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 Migration Pa thway Not Scored Surface Water Migration Pathway 100.00 Soil Exposure Pathway Not Scored Air Migration Pathway Not Scored

HRS Site Score 50.00

### 2 WORKSHEET FOR COMPUTING HRS SITE SCORE

S pathway S 2 pathway

Ground Water Migration Pat hway Score (S gw ) NS NS

Surface Water Migration Pathway Score (S

sw ) 100 10,000

Soil Exposure Pathway Score (S

s ) NS NS

Air Migration Score (S

a ) NS NS

S 2

gw + S 2

sw + S 2

s + S 2

a 10,000

(S 2

gw + S 2

sw + S 2

s + S 2

a )/4 2,500

/ (S 2

gw + S 2

sw + S 2

s + S 2

a )/4 50.0 0

Notes:

NS Not scored

### 3 T ABLE 4

- 1

-- S URFACE W ATER O VERLAND /F LOOD M IGRATION C OMPONENT S CORESHEET
Factor Categories and Factors Maximum

Value Value Assigned

Watershed Evaluated: Back River

Drinking Water Threat

Likelihood of Release:

1. Observe d Release 550 550
2. Potential to Release by Overland Flow:

2a. Containment 10

2b. Runoff 25

2c. Distance to Surface Water 25
2d. Potential to Release by Overland Flow [lines 2a(2b + 2c)] 500
3. Potential to Release by Flood:
3a. Containment (Flood) 10
3b. Flood Frequency 50
3c. Potential to Release by Flood (lines 3a x 3b) 500
4. Potential to Release (lines 2d + 3c, subject to a maximum of 500) 500
5. Likelihood of Release (higher of lines 1 and 4) 550 550

Waste Characteristics:
6. Toxicity/Persistence (a) 10000
7. Hazardous Waste Quantity (a) 100

8. Waste Characteristics 100 32

Targets:

9. Nearest Intake 50 0
10. Population:

10a. Level I Concentrations (b)

10b. Level II Concentrations (b)

10c. Potential Contamination (b)
10d. Population (lines 10a + 10b + 10c) (b)

11. Resources 5 0
12. Targets (lines 9 + 10d + 11) (b) 0

Drinking Water Threat Score:
13. Drinking Water Threat Score [(lines 5x8x12)/82 ,500, subject to a max of 100] 100 0

Human Food Chain Threat

Likelihood of Release:
14. Likelihood of Release (same value as line 5) 550 550

Waste Characteristics:
15. Toxicity/Persistence/Bioaccumulation (a) 5 x 10 8

16. Hazardous Wast e Quantity (a) 100

17. Waste Characteristics 1000 320

Targets:

18. Food Chain Individual 50 20
19. Population

19a. Level I Concentration (b)

19b. Level II Concentration (b) 0

19c. Potential Human Food Chain Contamination (b) 0.0 0000033
19d. Population (lines 19a + 19b + 19c) (b) 0
20. Targets (lines 18 + 19d) (b) 20

. 00000033
21. Human Food Chain Threat Score [(lines 14x17x20)/82500, subject to max of 100] 100 42.6 6

### 4 T ABLE 4

- 1

-- S URFACE W ATER O VERLAND /F LOOD M IGRATION C OMPONENT S CORESHEET
Factor Categories and Factors Maximum

Value Value Assigned

Watershed Evaluated: Back River

Environmental Threat

Likelihood of Release:
22. Likelihood of Release (same value as line 5) 550 550

Waste Characteristics:
23. Ecosystem Toxicity/Persistence/Bioaccumulation (a) 5 x 10 8

24. Hazardous Waste Quantity (a) 100

25. Waste Characteristics 1000 320

Targets:

26. Sensitive Environments

26a. Level I Concentrations (b)

26b. Level II Concentration s (b) 125

26c. Potential Contamination (b)
26d. Sensitive Environments (lines 26a + 26b + 26c) (b) 125
27. Targets (value from line 26d) (b) 125

Environmental Threat Score:
28. Environmental Threat Score [(lines 22x25x27)/82,500 subject to a max of 60] 60 60

Surface Water Overland/Flood Migration Component Score for a Watershed

29. Watershed Score c (lines 13+21+28, subject to a max of 100} 100 100
30. Component Score (S

sw ) c (highest score from line 29 for all watersheds evaluate d) 100 100

Notes:

a Maximum value applies to waste characteristics category

b Maximum value not applicable

c Do not round to nearest integer

### 5 REFERENCES

Please note that the number of pages listed for each reference indicates the number of pages included in the reference package for this Hazard Ranking System (HRS) document. Number of pages listed may or may not reflect the total number of pages contained in a complete copy of an original reference document.

Reference

Number Descript ion of Reference

1. U.S. Environmental Protection Agency (EPA). Hazardous Ranking System: Final Rule. Federal Register , Volume 55, No. 241. December 14, 1990. 138 pages.

2. EPA. Superfund Chemical Data Matrix. Excerpt. 20 pages. January 28, 2004. A complete copy of SCDM is available at http://www.epa.gov/superfund/sites/npl/hrsres/tools/scdm.htm.

3. Maryland Waste Management Administration . June 1985. A Preliminary Assessment of Sauer Dump, Dundalk, Maryland . 42 pages.

4. Tetra Tech EM I nc. (Tetra Tech). Site Location Map Sauer Dump. June 3, 2010. 1 page.

5. Halliburton NUS Corporation (formerly NUS Corporation). Expanded Site Inspection, Sauer Dump, Project No. 3739-16. ARCS III. March 1994. 633 pages.

6. NUS Corporation. Sit e Inspection of Sauer Dump. FIT 3. TDD No. F3 -8505-33. July 3, 1986.

213 pages.

7. Halliburton NUS Corporation. ARCH III , Field Activities Plan, Sauer Dump, Dundalk, Baltimore County, Maryland. November 5, 1992. 17 pages.

8. Tetra Tech. Sedim ent Sampling Location Map. October 27, 2010. 1 page.

9. Parsons Brinckerhoff. Tidal Back River, Small Watershed Action Plan. Prepared for the Maryland Department of Environmental Protection and Resource Management. February 2010. 337 pages.

10. Maryland Department of the Environment (MDE). Memorandum Regarding Sauer Dump. From Rick Grills. To Frank Henderson. March 4, 1991. 1 page.

11. EPA. Pollution Report ( Polrep ) Number 1 and Final, Sauer Dump Site. Prepared by Dennis

Matlock . March 20, 1991. 2 pages.

12. Federal Emergency Management Agency (FEMA). F lood Insurance Rate Map. B altimore County Maryland, Panel 440 of 580. Map Number 240010 0 440F. Map Revised September 26, 2008. 1 page.

13. Tetra Tech. 15

- Mile Target Dist ance Map. Sauer Dump. October 25, 2010. 1 page.

### 6 14. E nvironmental Service and Technology Corporation (ENSAT) . Remedial Investigation Sauer Dump, MD-181 – 4225 Lynhurst Road, Baltimore, Baltimore County, Maryland. August 2005. Volume I and Volume II, 1,651 pages.

15. Tetra Tech. Sauer Dump Source 1 Location Map. October 27, 2010. 1 page.

16. Halliburton NUS Corporation, ARCH III. Expanded Site Inspection of Sauer Dump, Logbook Nos. P022 and P023. Project No. 3738-1605. December 7, 8, and 9, 1992. 41 pages.

17. Severn Trent Laboratories (STL). Analytical Report. Malcolm Pirnie Sauer Dump Site. Lot#: C7A130135. February 13, 2007. 2,771 pages.

18. STL. Analytical Report. Malcolm Pirnie Sauer Dump Site. Lot#: C7A110281. January 19, 2007. 724 pages.

19. Tetra Tech. Project Note Regarding Latitude and Longitude of Source 1 . Prepared by Alicia Shultz, HRS Specialist. December 14, 2010. 1 page.

20. Agency for Toxic Substances and Disease Registry (ATSDR). Po lychlorinated Biphenyl Health Statement. November 2000. 10 pages.

21. EPA. Sauer Dump Site: Administrative Order for Removal Response Action. EPA Docket No.

CERC -03-2006-0239DC. August 18, 2008. 27 pages.

22. EPA. Using Qualified Data to Docume nt an Observed Release and Observed Contamination

. Directive 9285.7-14FS, PB94-963311, EPA \540\F-94\028. November 1996. 18 pages.

23. EPA. Action Memorandum – Request for Removal Action and Exemption from the $2 Million Statutory Limit at the Sauer Dump Site, Baltimore County, Baltimore, MD. August 3, 2007. 17

pages.

24. Malcolm Pirnie. Field Sampling Plan. November 30, 2006. 69 pages. Appendix A, 80 pages.

25. Malcolm Pirnie, Inc. Sauer Dump Site Dund al k, Baltimore County, Maryland – Re sponse Action

Plan – Revision 2 (Final). November 30, 2006. 59 pages. Appendix B, 6 pages. Appendix E, 119 pages.

26. Baltimore County, Maryland. Zoning Map for Sauer Dump. 4 pages. Undated. Accessed OnLine at: http://www.baltimorecountymd.gov/Agencies/myneighborhood/zoning.html

.

27. MDE. Letter Regarding Re quest for Information from MDE Sauer Dump file, Copy of October 24, 1990 A nalytical D ata and S ite S ket ch Attached. From Louise Connelly, Public Information

Officer. To Sandra Williams, b lueskies environmental a ssociates, inc. March 3, 2005. 14 pages.

28. MDE. Letter Regarding Re quest for Information from MDE Sauer Dump file, Copy of April 4,

1996 An alytical D ata and S ite S ketch Attached. From Louise Connelly, Public Information

Officer. To Sandra Williams, b lueskies environmental a ssociates, inc. March 18, 2005. 48

pages.

### 7 29. MDE. Sauer Dump Resampling Report MD-181. May 26, 2000. 33 pages.

30. Genium Publishing Corporation. Guide to Environmental Analytical Methods, 3 rd Edition. EPA. Contract Laboratory Program. Copyright 1996. Excerpt 4 pages.

31. Malcolm Pirnie, Inc. Extent of Contamination Study (Revision 1.0) Former Sauer Dump and

Salva ge Yard. June 26, 2007. 192 pages.

32. Critical Area Commission for the Chesapeake and Atlantic Coastal Bays. Preserving Our Precious Natural Resources. Accessed on June 28, 2010. 2 pages.

33. Tetra Tech. Source 1 Sampling Locations. October 27, 2010. 1 page.

34. Tetra Tech. Sauer Dump, Dundalk Maryland (Perimeter of Level II Wetland) . February 16, 2012. 1 page.

35. U.S. Geological Survey (USGS). Middle River, Maryland Topographic Map. 1969. Photorevised 1985. 1 page.

36. U.S. Fish and Wildlife Se rvice (USFWS) , Chesapeake Bay Program. Federally Listed Endangered an d Threatened Species of Maryland. February 12, 2010. A vailable On

- Line at: http://www.fws.gov/chesapea kebay/EndSppWeb/lists/specieslist -md.html . 4 pages.

37. STL Pittsburg. Analytical Report. Project No. Sediment. Malcolm Pirnie Sauer Dump Site. Lot #: C7A110284. February 19, 2007. 1,995 pages.

38. USFWS. Shortnose Sturgeon Species Profile. May 11, 1967. 1 page.

39. National Oceanic and Atmospheric Administration (NOAA) . Species Profile Shortnose Sturgeon. Undated. A vailable On

- Line at: http://www.nmfs.noaa.gov/pr/species/fish/shortnosesturgeon.htm . 3 pages.

40. STL Pittsburg. Analytical Report. Project No. Sediment. Malcolm Pirnie Sauer Dump Site. Lot #: C7A130138. February 19, 2007. 3,158 pages.

41. Critical Area Commission for the Chesapeake and Atlantic Coastal Bays. Maryland Critical Area Frequently Asked Questions. Accessed on June 30 , 2010. Available On

- Line at: http://www.dnr.state.md.us/criticalarea/faq.html#1 . 4 pages.

42. EPA. Comprehensive Environmental Response Compensation and Liability Information System (CERCLIS) Query Results for Sauer Dump. Accessed On October 12, 2010. On- Line Address: http://oaspub.epa.gov/enviro/cerclis_web.report?pgm_sys_id=MDD981038334 . 2 pages.

43. Chesapeake Bay Foundation. Bay Area Facts. Accessed on October 13, 2010. On- Line

Address: http: //www.cbf.org/Page.aspx?pid=433 . 2 pages.

44. NOAA. Ecosystem Based Fisheries Managerment. Accessed October 13, 2010. On

- Line

Address: http: //chesapeakebay.noaa.gov/ecosystem

- based

- management/ecosystem

- based

fisheries

- management . 1 page.

45. NOAA. Blue Crab. Accessed on October 13, 2010. On-Line Address:

### 8 http://chesapeake bay.noaa.gov/fish

- facts/blue

- crab . 3 pages.

46. NOAA. Blue Crab. Accessed on October 13, 2010. On-Line Address: http://chesapeakebay.noaa.gov/fish

- facts/oysters . 4 pages.

47. EPA. Action Memorandum – Request for Removal Action and Exemption from the $2 Million Statutory Limit at the Sauer Dump Site, Baltimore County, Baltimore, MD. September 27, 2005. 17 pages.

48. Tetra Tech. Background Soil Sampling Location Map. June 29, 2010. 1 page.

49. Maryland Department of Health and Mental Hygiene. Hazardous Waste Laboratory Organic and Inorganic Analysis Report Form for S-9. Various Dates. 3 pages.

50. STL. Analytical Report. Malcolm Pirnie Sauer Dump Site. Lot#: C7 A240133. February 6, 2007. 800 pages.

51. STL. Analytical Report. Malcolm Pirnie Sauer Dump Site. Lot#: C7A250145. February 19, 2007. 1,599 pages.

52. Tetra Tech. Adjusted Detection Limits. Prepared by Alicia Shultz, HRS Specialist. Dece mber 13, 2010. 4 page s.

53. Tetra Tech. 1992 Sediment Sampling Locations. October 27, 2010. 1 page.

54. NOAA. Findings for Maryland Coastal Nonpoint Program. Undated. 19 pages.

55. NOAA. Approval of Maryland Coastal Management Program. 52 pages. Undated. On- Line

address: http://www.dnr.state.md.us/ccp/pdfs/NOAA_MDCMP.pdf

.

56. Maryland Chesapeake and Coastal Program, Department of Natural Resources. Electronic Mail

from Joseph Abe, Coastal Policy and Project Review Specialist. To Alicia Shultz, Tetra Tech, HRS Specialist. October 25, 2010. 2 pages.

57. ENSAT Corporation. Sampling and Analysis Plan For Sauer Dump 4225 Lynhurst Road, Dundalk, Baltimore City, Maryland, Control No. MD-181. December 4, 2001. 55 pages.

58. EPA. Modifications Updating SOM01.1 to SOM01.2. October 5, 2006. 47 pages. (cited in Reference 52)

59. EPA. Introduction to Analytical Methods. Exhibit D – Analytical Methods. Undated. 133

pages. (cited in Reference 52).

60. United States Geological Survey. Map of Real -Time Streamflow. December 17, 2010. 1 page.

61. EPA. Aerial Photographic Analysis and Wetland Analysis of Sauer Dump Study Area, Dundalk, Maryland. February 2012. 33 pages.

62. Tetra Tech Inc. Wetland Delineation Report, Sauer Dump Site, Baltimore County, Maryland. February 2012. 56 pages.

### 9 63. Maryland Department of Natural Resources. Email Regarding Back River Fishing and Fish Consumption Inquiry . From Mart in L. Gary

, Assistant Director/Fisheries Ecologist , Maryland Department of Natural Resources Fisheries Service . To Alicia Shultz , Tetra Tech, HRS Specialist . January 27, 2012. 1 page.

### 10 ACRONYMS AND ABBREVIATIONS

μ g/kg Microgram per kilogram

μ g/L Microgram per liter

ASTM American Society for Testing and Materials

ATSDR Agency for Toxic Substances and Disease Registry

BCHD Baltimore County Health Department bgs Below ground surface

BPFV Bioacccumulation Potential Factor Value

CLP Contract Labo ratory Program

COC Chain -of-Custody

COMAR Code of Maryland Regulations

EPA U.S. Environmental Protection Agency

ERRP Environmental Restoration and Redevelopment Program

ESI Expanded Site Inspection

FIT Field Investigation Team

FSP Field Sampling Plan

ft Feet

ft 2 Square feet

HRS Hazard Ranking System HWQ Hazardous Waste Quantity

MWMA Maryland Waste Management Administration

MD HSWMA Maryland Hazardous and Solid Waste Management Administration

MDE Maryland Department of the Environment

MWMA Maryland Waste Management Administration mg/kg Milligram per kilogram

NLP National Priorities List

NOAA National Oceanic and Atmospheric Administration

NS Not scored

PA Preliminary Assessment

PAH Polyaromatic hydrocarbon

PCB Polychlorinated biphenyl

PPE Probable point of entry QA/QC Quality Assurance and Qualit y Control QAPP Quality Assurance Project Plan

RAP Remedial Action Plan

RI Remedial Investigation

SCDM Superfund Chemical Data Matrix

SI Site Inspection SQL Sample Quantitation Limit

S OP Standard Operating Procedure

SOW Statement of Work

SVOC Semivolatile organic compounds

TAL Target Analyte List

TCL Target Compound List

TDL Target Distance Limit

TP Test Pit

USACE US Army Corps of Engineers

VOC Volatile organic compound

### 11 INTRODUCTION

The Sauer Dump site is located at 4225 Lynhurst Road in Dundalk, Baltimore County, Maryland ( Ref. 4; Ref. 14, pp. 9, 96; Ref. 42, p. 1; and Figure 1 of this documentation record ). Sauer Dump is bordered by

a cove of Back River and tidal wetlands to the south, and non- tidal wetland areas to the southwest

, northwest, and southeast. A pond is present in the non- tidal wetland area on the northwest portion of the property (Ref. 14, pp. 9, 10; Ref. 15; Ref. 31, pp. 8, 74; and Figure 2 of this documentati on record ). Residential properties border Sauer Dump to the northeast, east, and southeast. Undeveloped land borders Sauer Dump to the southwest , west, and northwest ( Ref. 25 , p. 10; Ref. 14, p. 10; and Figure 2 of

this documentation record ).

The Sauer Dump is an inactive, privately owned, unpermitted, former dump. While in operation,

hazardous substances were improper ly store d and dispos ed of at the Sauer Dump from the 1960s to the 1980s ( Ref. 14 , pp. 3, 9 ). In 2007, Sauer Dump was used for vehicle maintenance and storage , and sportsmen hunted duck on the property in the fall. All -terrain vehicles were used on the property, causing erosion and expos ing contaminated soils ( Ref. 23 , p. 7).

Reference documentation identifies Sauer Dump as a 2.48- acre property on land Parcel 425. However, descriptions of the dump operations indicate that dumping activities extended onto adjacent parcels and the contamination resulting from operations migrated beyond Parcel 425 (Ref. 14, pp. 9, 96; Ref. 21, p. 4;

Ref. 3 1, pp. 8, 23, 28 to 31, 74; Ref. 47, p. 3). Analytical data from samples collected from Sauer Dump indicate that contamination from the dump has spread to adjacent properties via vehicle traffic or other transport mechanisms (Ref. 31, pp. 23, 30). Therefore, the area of the Sauer Dump is more than 2.48

acres. The exact dimension of Sauer Dump cannot be determined from data currently available.

In the middle to late 1950s, Sauer Dump was owned by William Lusk (Ref. 3, p. 20). According to

historic rec ords, Sauer Dump was bought by the late Frederick Sauer from Irene Sessa in approximately 1963. Historic records do not indicate when Irene Sessa bought the property or how she used it (Ref. 6, p. 9). In December 1992, Fred Sauer (the son of the late Frederick Sauer) and the Beachwood Development Corporation owned the property (Ref. 7, p. 1). On January 16, 1997, Sauer Dump was acquired by the Wittstadt Hunting Club, Inc. (Ref. 14, p. 10). As of 2006, Sauer Dump was still owned by Wittstadt Hunting Club, Inc. (Ref. 25, p. 10).

A 2012 aerial photographs analysis showed that in 1938 the Sauer Dump area was undeveloped woodland and emergent herbaceous wetland. By 1957 Lynhurst Road was in place and single family houses had been constructed along the road. Fill deposits had been placed into the wetland during the construction of a peninsula located east of the Sauer Dump. These fill deposits were visible in 1954 and 1957. By 1964 the filling of the peninsula appeared complete. Filling activity was also evident at the northeast edge of the Sauer Dump area extending southwest from parcels 503, 464, and 295. Filling/dumping continued

near the northeast edge of the Sauer Dump area through 1969. By 1971 dumping activity had extended into the central portion the Sauer Dump area, formerly occupied by wetland as late as 1964. By 1973 dumping operations at the Sauer Dump area had expanded to areas south of parcel 295 and to the west of parcel 137. By 1986 the accumulations of dumped material at the Sauer Dump area appeared to have reached their largest extent. Piles of debris, fill, probable solid waste, numerous containers, trailers, trucks, a crane, and derelict vehicles were noted. Dumping continued through 1990 and 1992. By 1995 dumping at the Sauer Dump area appeared to have ceased and revegetation in the central portion of the Sauer Dump was evident (Ref. 61, pp. 1, 2 , 10, 11 ).

Frederick Sauer owned Sauer Dump when primary filling activities occurred (Ref. 6, p. 9). Records do

not indicate whether the same fill material was used on Sauer Dump and the adjacent properties. The source of the fill material and the persons responsible for filling the areas has not been identified.Parcel 425 Approximate limit of fill material (Source 1)

Parcel 503

Parcel 574 Parcel 46

P arcel 2 4

95

Parcel 137

Approximate Location of Dump =

Maryland Lynhurst Rd.

Source: Reference 14, page 96

Legend

Approximate Limit of Fill Material (Source 1)

Surrounding Parcel

Parcel 425 0 65 130 Feet



### DUNDALK, BALT SAUER DUMP

IMORE COUNTY, MARYLAND

FIGURE 2

SAUER DUMP SOURCE 1 LOCATION MAP

Map created on October 27, 2010 by TDD No. E33-030-10-05-002

Collin Horace, Tetra Tech EM Inc. EPA Contract No. EP-S3-05-02 260

### 14 According to interviews with neighbors of Sauer Dump, a flatbed tractor trailer disposed of numerous 55

- gallon drums at the dump in the mid-1970s. The drums were leaking and contained an oily liquid substance. Information gathered in another interview indicated that Mr. Sauer operated a waste hauling

business at the dump from the late 1960s to the mid- 1980s and disposed of hauled waste including paint and creosote wastes (Ref. 47, p. 5).

Wastes observed at Sauer Dump during site investigations include drums, storage tanks , salvage items ( such as scrap metal ), empty tanks and drums, abandoned trucks, tractor/truck trailers, open roll- off containers, heavy construction equipment, and junked cars. Charred areas, burned paint waste, a wood chip mound, and sections of large- diameter circular concrete conduit hav e also been observed, and oil spill areas have been observed on site and in wetland areas adjacent to the property . Studies conducted at Sauer Dump between 1985 and 1999 indicate that concentrations of semivolatile organic compounds ( SVOC ) , metals, polych lorinated biphenyls ( PCB ), and pesticides found in the soil and sediment exceed

various risk

- based screening levels ( Ref. 10; Ref. 11, p. 1; Ref. 14, p. 3).

The primary source identified at Sauer Dump is a landfill (Source 1). The source is classified as a landfill

because the source was created when wastes were filled into the wetlands on the property (Ref. 3, pp. 1,

22 ; Ref. 61, pp. 1, 2 ). Evidence shows contaminated soil outside the area estimated to have been filled

and identified as Source 1 . Howev er, an area of contaminated soil has not been documented because of the lack of background samples collected during investigations conducted at Sauer Dump (Ref. 14, pp. 9, 96; Ref. 21, p. 4; Ref. 31, pp. 8, 23, 28 to 31, 74; Ref. 47, p. 3). The precise bo undaries of the landfill cannot be identified because existing data do not sufficiently delineate the aerial extent of the landfill and contamination. The extent of Source 1 (fill area) has been estimated based on the topography of the area, information g athered during subsurface investigations , and an onsite survey (Ref. 15 ; Ref. 14, pp. 13, 96, 109, 110). The dashed line on in Figure 2, Reference 14, page 96 identifies the approximate limits of the fill and the original elevation of the site based on an onsite survey (Ref. 14, p. 96). Subsurface investigations conducted at Sauer Dump identified waste material such as metal, rubber, batteries, electrical parts, and other fill material throughout the subsurface soils of the dump (Ref. 14, pp. 13, 14).

Th e primary hazardous substances associated with Source 1 are lead and PCBs (Ref. 31, pp. 28 to 31). Source 1 is located in the flood plain of the Back River and is subject to flooding and erosion during severe weather events (hurricanes, tropical storms, h eavy rain) ( Ref. 23, p. 7 ; Ref. 12 ). A wetland surrounds Source 1 along its eastern, southern, and western boundaries. The wetland receives surface water runoff from Source 1. Sediment samples collected from the wetland contain PCBs and lead at concentrations meeting the criteria for an observed release to surface water and actual contamination of a wetland (Ref. 31, pp. 32, 33, 80; Ref. 34; and Section 4.1.4.3 of this documentation record). The wetland discharges to Back River, which in turn flows to t he Chesapeake Bay (Ref. 34; Ref. 13). The Back River and Chesapeake Bay are fisheries (Ref. 9, pp. 32, 65, 66 ; Ref. 63 ). Targets evaluated include the wetlands on the eastern, southern, and western boundaries of Source 1 and fisheries associated with Bac k River and Chesapeake Bay.

According to the Baltimore County Department of Permits and Development Management, Sauer Dump

is zoned as a Resource Conservation Critical Area (Ref. 26) under the Critical Area Act . In 1984, the Maryland General Assembly resolved to reverse the deterioration of Chesapeake Bay’s environment by enacting the Chesapeake Bay Protection Act. In 2002, the Act was amended to include the Atlantic Coastal Bays. The Act required the 16 counties, Baltimore City, and 44 municipalities surrounding the Chesapeake and Atlantic Coastal Bays to implement a land use and resource management program designed to mitigate the damaging impact of water pollution and loss of natural habitat, while also accommodating the jurisdiction’s future growth. The Critical Area Act recognizes that the land immediately surrounding the Bays and their tributaries has the greatest potential to affect water quality and wildlife habitat and thus designated all lands within 1,000 feet of tidal waters or adjacent tida l

wetlands as the “Critical Area ” (Ref. 41, p.1).

### 15 Previous i nvestigations conducted at the property are summarized in the section below.

Summary of Investigations at the Sauer Dump Site

On November 8, 1954, the Baltimore County Health Department (BCHD) performed an inspection on Mr. Lusk’s property (Sauer Dump) because of complaints by adjacent property owners of floating debris on Back River. According to BCHD, the property consisted of marshland (wetland) fronting the Back River that was being filled with material consisting mainly of plasterboard and “other waste materials of

an inert nature ” (Ref. 3, p. 22). A number of areas on Sauer Dump had been raised to several feet above

normal water levels because of dumping operations. Adjacent property owners complained about floating

debris that consisted of paper that had separated from plasterboard when it was immersed in water. Mr. Lusk was near completion of filling operations and was planning to cover the area with earth and building

materials. No a ction was taken against Mr. Lusk (Ref. 3, p. 22).

On April 4, 1984, BCHD conducted an inspection of Sauer Dump in response to a request for an evaluation by a proposed developer (Ref. 3, p. 1). A large quantity of debris was observed during the inspection, including auto parts, empty drums, wood, and plastic products. On April 12, 1984, BCHD ordered Mr. Sauer to clean up Sauer Dump within 60 days a s a result of this inspection, citing violations of the County Code (Ref. 3, p. 20).

During a follow-up inspection on May 4, 1984, BCHD found that the Sauer Dump had accepted no

additional waste since the April 1984 inspection . On June 8, 1984, BCHD examined the property and found that little progress had been made in cleaning up the property (Ref. 3, p. 21).

During an inspection of Sauer Dump on October 2, 1984, BCHD found that 60 to 70 percent of the cleanup had been completed. On January 24, 1985, the Maryland Waste Management Administration (MWMA), accompanied by BCHD, conducted a preliminary assessment (PA) of Sauer Dump. Approximately 70 percent of the original debris had been removed from the property. A small quantity (5 to 10 cubic yards) of refuse had been brought on to the property since the October 1984 inspection (Ref. 3, p. 21). The following wastes were observed on site: paper, lumber, scrap metal, demolition debris, old empty trailers, junked cars, a couple of cranes and dozers , and about 10 to 12 empty and rusted drums. No evidence of hazardous materials or water contamination problems was observed (Ref. 3, p. 2). The PA report sta tes that the owner had no records of the waste types and quantities disposed of at Sauer Dump (Ref. 3, p. 4). MWMA and BCHD observed two burn areas on the property : an approximately 30- by 30- foot area of charr ed debris and ashes on the southern border of the property and an empty, rusted

roll -off truck box that was used for burning paint off scrap metal. The PA report states that Sauer Dump had been used to store approximately 250 empty drums, which were removed in summer 1984 (Ref. 3, pp. 2, 6).

On June 27, 1985, EPA Region 3's Field Investigation Team (FIT), accompanied by representatives from EPA, MWMA , and BCHD, conducted a site inspection (SI) of the Sauer Dump (Ref. 6, p. 26-27). During

the June 1985 SI , the following wastes were observed on site: large piles of construction debris (concrete, wire, plaster, rebar, and wood); large, empty storage tanks; several empty trucks and trailers; metal scrap;

an open- ended dumpster that served as a burn area; and a former burn area covered with wood chips (Ref. 6, p. 6 and 72). Analytical results from on- site surface soil, subsurface soil, and sediment samples collected as part of the SI revealed PCB concentrations up to 267 .899 milligrams per kilogram (mg/kg)

. An on- site surface water sample revealed PCB concentrations at 29.9 micrograms per liter (μg/L) (Ref. 6, p. 60). Various polyaromatic hydrocarbons (PAH) and phthalates were detected in on- site surface soil, subsurface soil, surface water

, and sediment samp les (Ref. 6, p. 57 ).

### 16 Maryland Department of the Environment (MDE) collected additional samples at Sauer Dump on October 24, 1990. Analytical results revealed PCBs at 110 mg/kg and 62 mg/kg in soils adjacent to the on-site tidal channel (Ref. 27, pp. 1, 13 and 14). On March 1, 1991, MDE and U.S. Environmental Protection Agency ( EPA ) Region 3 completed a removal assessment of Sauer Dump in response to the

elevated levels of PCBs detected in on

- site soils ( Ref. 10; Ref. 11). The following observations wer e recorded during the removal assessment (Ref. 11):

• Three empty storage tanks with a capacity of up to approximately 2,000 gallons

• Approximately 50 empty and rusted 55- gallon steel drums

• Several pieces of heavy equipment in various stages of decay (crane s, roll-off boxes, and box trailers)

• An area currently utilized for welding operations

• Evidence of on-going fill and grading operations using construction and metal debris (Ref. 11)

After discussing Sauer Dump with EPA’s removal section

, EPA’s site assess ment section made plans to

conduct an expanded site inspection (ESI) ; therefore

, a removal action was not deemed necessary at the time (Ref. 11, p. 2).

In December 1992, EPA Region 3 contractors conducted an ESI of the Sauer Dump (Ref. 5, p. 6 ). Samples were collected from on

- site surface soils, surface water , and sediment. Surface water and sediment samples were also collected from the Back River (Ref. 5, p. 22). Analytical results of o n- site

surface soil samples revealed elevated levels of Aroclor 125 4 (up to 150 mg/kg ) and phenol (up to 21 mg/kg ); the PAH naphthalene (up to 20 mg/kg ); and several other PAHs and metals including arsenic, chromium, lead, manganese, and nickel. Analytical results of o n- site sediment samples revealed elevated

levels of A roclor 1254 ; several metals including chromium, lead, and nickel ; and several PAHs. Results

from o n- site surface water samples revealed elevated levels of metals (Ref. 5, pp. 29, 56, 60, 61, and 93).

On April 4, 1996, MDE personnel collected six soil and five sediment and surface water samples from Sauer Dump (Ref. 28 , p. 2 ). The PCB Aroclor 1254 was reported at a maximum concentration of 44 mg/kg in one soil sample, and at a maximum concentration of 0.3 mg/kg in two sediment samples

collected in the wet lands located adjacent to the Back River (Ref. 28, pp. 2 and 37).

In late 1999, MDE collected soil, sediment, ground water, and surface water samples from Sauer Dump (Ref. 29). Elevated levels of inorganics were detected in soil and sediment samples collected throughout the entire property. Elevated concentrations of semivolatile organic compounds ( SVOC ) in the soil (benzo-a-pyrene up to 7,323 micrograms per kilogram [μg/kg] ) were detected predominately in the southern portion of the property. The PCB Aro clor 1254 was detected at elevated levels (ranging from

0.7 to 84 mg/kg ) in the majority of soil samples collected throughout the property. PCB concentrations reported in sediment samples collected from Sauer Dump ranged from 0.4 to 14.4 mg/kg (Ref. 29, p. 3 ).

In 2001, an environmental consultant to MDE was tasked under MDE’s Environmental Restoration and Redevelopment Program (ERRP) to perform an RI of Sauer Dump ( Ref. 14 , p. 3). The field investigation portion of the RI was performed to fill data gap s left from the available reports ( Ref. 14, p. 3). During the
RI, t he property was observed to be heavily overgrown with vegetation and exhibited irregular topography. At the time that the 2001 RI was conducted, t he property continued to serve as a storage area for large items owned by various Sauer family members, including boats, vehicles, and large construction equipment. Scrap metal, domestic refuse , and construction debris remained throughout the property and in some adjacent areas off site ( Ref. 14, p. 12).

During the RI field investigation s conducted in 2001 to 2002, subsurface soil samples were collected from nine test pits excavated at the property , five ground water monitoring wells were installed and sampled,

### 17 and five soil borings were advanced and sampled. In addition, a topographical survey and wetland

delineation was conducted for Sauer Dump and immediately surrounding land (Ref. 14, pp. 12, 13, 16).

As o bserv ed during test pit excavation, the fill at Sauer Dump consist ed of wood, plastic, metal, rubber, brick, sand, black sand/soil

, concrete and concrete castings, asphalt, ash, electrical transformer parts, paint/paint containers, batteries, crushed drums, railroad ties, styrofoam, and a white/gray powdery substance (Ref. 14 , p. 3).

In January 2003, the Agency for Toxic Substances and Disease Registry (ATSDR) concluded that lead and PCBs detected in surface soil samples at Sauer Dump was a public health hazard for a nearby residents, and that PCBs detected in subsurface soil samples wer e a potential public health hazard if

contaminated soils were exposed during gardening or construction activities involving digging or trenching ( Ref. 21, p. 6).

In December 2005, EPA issued an Administrative Order for Removal to the Sauer Dump mandating that property owners place a fence around the property to restrict access, install a temporary cover system over contaminated areas to mitigate erosion of surface soils, and protect the shoreline from erosion

. As a result of the 2005 Order, a chain- link f ence now restricts public access to the majority of Sauer Dump

, plastic nylon- reinforced polyethylene sheeting covers a small area o f Sauer Dump disturbed during remedial investigation s, and shoreline erosion structures such as coconut fiber logs have been installed to prevent erosion ( Ref. 21 , p. 7 ; Ref. 31 , p. 12).

In January 2007, a contractor to MDE conducted an extent of contamination study of Sauer Dump that

included surface and subsurface soil, sediment, and surface water sampling. A total of 32 surface soil, and 9 subsurface soil samples were collected. The surface soil samples were analyzed for lead and PCBs

. The subsurface soil samples were collected from 2 to 3 feet below ground surface ( bgs ) and were analyzed for PCBs, lead, volatile organi c compounds ( VOC ), and SVOCs. Aroclor 1260 was t he most commonly detected PCB compound, identified in 25 of the 32 surface soil samples and 8 of the 9 subsurface soil samples. Lead was detected in all of the surface and subsurface soil samples. The high est
concentrations of PCB s (up to 7.7 mg/kg in surface soil and 1.6 mg/kg in subsurface soil) and lead (up to 2,720 mg/kg in surface soil and 13,100 mg/kg in subsurface soil) were observed in soil samples collected from the hot spots (areas with historical ly high lead and PCB concentrations) on Sauer Dump. Low concentrations of VOCs and SVOCs were detected in several of the subsurface soil samples (Ref. 31, pp.

14 to 16 , 22 to 25, and 65 to 68).

A total of nine sediment samples were collected from Sauer Dump as part of the 2007 extent of contamination study, including seven from the wetlands, one from the pond area, and one from Back River. The sediment samples were collected from the top 6 inches of sediment below the organi c buildup . The sediment samples were analyzed for lead and PCBs by EPA Methods 8082 (total PCBs) and 1668 (PCB homologues) (Ref. 31, pp. 24, 25, and 80). Lead and PCBs were detected in the wetland surrounding the pond on the northern portion of Sauer Dump (Wetland #1) and in the we tland that surrounds the eastern, southern, and western portions of Sauer Dump (Wetland #2) (Ref. 31, pp. 25 , 69, 80). Total PCBs and lead in Wetland #1 were detected at concentrations up to 0.33412 mg/kg and 47.01 mg/kg, respectively. Total PCBs and lea d in Wetland #2 were detected at concentrations up to 38.7 mg/kg and 4,800 mg/kg, respectively (Ref. 31, pp. 25 and 69).

Two surface water samples were collected from the shoreline of Back River. The samples were collected soon after the peak of high tide. F iltered and unfiltered samples were collected and analyzed for lead and

PCBs. PCBs were not detected in the unfiltered and filtered samples when analyzed using EPA Method 8082; however, PCBs were detected at low concentrations in both types of sam ples when analyzed with EPA Method 1668, which screens for all 209 PCB congeners. Lead w as detected in one filtered and both unfiltered samples ( Ref. 31 , p p. 14 to 16 , 35, 22-25, 70; Ref. 25, p. 37 ).

### 18 Five ground water wells were installed in January 2007. In February 2007, samples were collected from the five wells and analyzed for PCBs and total and dissolved lead. PCBs were detected in only the unfiltered samples from MW -4 when analyzed using EPA Method 8082, which tests for seven of the 209 possible PCB congeners. When the samples were analyzed using EPA Method 1668, which screens for all 209 PCB congeners, PCBs were detected in both the filtered and unfiltered samples from all five wells. Lead was detected in three of the unfiltered samples ( Ref. 3 1, pp. 16, 18, 26, 27, 71, 72; Ref. 25, p.

37 ).

Investigations conducted at the Sauer Dump identified an area of PCB and lead contamination in Source 1 waste that released lead and PCBs to wetlands located along the eastern, southern, and western borders of Source 1 and adjacent to the Back River, as documented in this HRS documentation record.

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19 SOURCE DESCRIPTION

2.2 Source Characterization

Source Number : 1

Source Description : Landfill

Source Type : Landfill

Source 1 is a la ndfill created when wastes were filled into wetland (marshland) adjacent to the Back River (Ref. 3, p. 1; Ref. 61, pp. 1

, 2). During investigations conducted in Source 1, wood, plastic, metal, rubber, brick, sand, black sand/soil, concrete and concrete castings, asphalt, ash, electrical transformer parts, paint/paint containers, batteries, crushed drums, railroad ties, styrofoam, and a white/gray powdery

substance were observed in the subsurface soil ( Ref. 14 , pp. 3, 26, 126 to 149). This waste material is referred to as fill in reference documentation. Test pits in Source 1 identified fill from the surface to below the water table (Ref. 14, pp. 13, 14). Subsurface soil borings in Source 1 revealed the presence of wood, plastic, metal, wire, rubber, bric k, sand, rock fragments/gravel, glass, concrete, asphalt, ceramic tile, mattress pieces, and paper in fill found in Source 1 (Ref. 14, pp. 14, 126 to 149; Ref. 31, pp. 93 to 103).

Source 1 is estimated to cover at least 2. 48 acres, which is the area of Parcel 425 on which the fill is located (Ref. 15; Ref. 14, pp. 9, 96 ). The area of the fill has been estimated from elevations on Sauer Dump and is shown in Reference 15.

Source 1 was used during the 1960s through 1980s as an unpermitted landfill/ dump (Ref. 3, p. 1 ; Ref. 14

, p. 9). During operations , hazardous wastes were improper ly stor ed and dispos ed in this area (Ref. 14, p. 9). The oldest evidence supporting the use of Source 1 as a landfill is photographs and an inspection

report dated 1954. Th e 1954 inspection report stated that the land being filled consisted of wetland (marshland) fronting the Back River (Ref. 3, p. 1). An aerial photograph from 1964 shows Sauer Dump

as emergent herbaceous wetland (marshland) with filling/dumping evident at the northeast edge of the Sauer Dump area . The unfilled emergent herbaceous wetland (marshland) is shown in a 1938 aerial photograph (Ref. 61, pp. iii, 10, 11, 16, 17 ). Filling/dumping had reached the central portion of the Sauer Dump by 1971, and it rea ched its largest extent by 1986 (Ref. 61, pp. iii, 18, 19, 22, 23).

No records of the sources, types , and quantities of wastes disposed in Source 1 have been identified (Ref. 3, p. 4). Wastes potential ly containing hazardous substances observed on the s urface of Source 1 include large piles of construction debris (concrete, wire, plaster, rebar, and wood); large, empty storage tanks; railroad ties; several empty trucks and trailers; scrap metal; an open -ended dumpster that served as a burn

area; drums; and a former burn area covered with wood chips (Ref. 3, pp. 2, 3, 5, 6, and 8; Ref. 5, p. 24; Ref. 6, p. 72; Ref. 10, p. 1; Ref. 11 ). Refuse possibly containing hazardous substances has been observed throughout Sauer Dump and on the surface of Source 1 (Ref. 6, p. 10; Ref. 11). Approximately 250 empty drums were disposed of and removed from Sauer Dump in 1984 (Ref. 3, pp. 3, 6 ). Because the contents and handling of these drums while they were on- site are not known, the drums represent a possible source of contamination (Ref. 3, p. 5). The source of the waste materials is not provided in site documentation (Ref. 6, p. 24; Ref. 11).

### SD

- Waste Characteristics

20 Source Location:

Source 1 is located at 4225 Lynhurst Road in the Dundalk, Baltimore County, Maryland (Ref. 15 ). Based on figures prepared during on- site surface and subsurface investigations at Sauer Dump, the extent of the Source 1 (landfill) is estimated based on raised elevations indicating that the area has been filled, as shown in Reference 15. The outline of Parcel 425 is provided on Reference 15 showing that the landfill extends beyond the Parcel 425. Source 1 is bordered by a cove of the Back River and tidal wetlands to the south, and by non- tidal wetland areas to west

, northwest, and east . A pond is present in t he non- tidal wetland area northwest of Source 1 (Ref. 31, pp. 8, 11, 74; Ref. 15; Ref. 33; Ref. 34 ). The locations of Source 1 waste samples showing concentrations of lead and PCBs are shown in Reference 33.

Containment :

Release to ground water : The g round water pathway was not scored.

Release via overland migration and/or flood:

Release to surface water: Source 1 is located adjacent to Back River. Tidal and non

- tidal wetlands are located along the eastern , southern, western, and northwestern boundaries of Source 1 ( Ref. 14 , p. 3 ; Ref. 15; Ref. 34; Ref. 62, pp. 8 , 9, 17). As described in this section, contamination has been documented at

Source 1. There is no evidence that a maintained , engineered cover or functioning and maintained run-on

control system and runoff management system is in place at Source 1. There is also no documentation supporting that containment at Source 1 was designed, constructed, operated, and maintained to prevent a washout of hazardous substances by a flood. For these re asons, a containment factor value of 10 was assigned to the source (Ref. 1, Table 4 -2; Ref. 3, p. 15).

Gas release to air: The air migration pathway was not scored.

Particulate release to air: The air migration pathway was not scored.

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21 2.4 WASTE CHARAC TERISTICS

2.4.1 Hazardous Substances

Numerous source sampling investigations have been conducted to characterize Source 1. The results of these investigations document the presence of contaminat ion in the surface (0 to 2 feet bgs) and subsurface (2 feet or greater bgs) of Source 1 ( Ref. 14 , pp. 3, 4, 11-12, and 18-19).

The samples collected from Source 1 have been described as surface soil, subsurface soil, and fill material in reference documentation. Because Source 1 includes a filled marsh (landfill), all samples collected from Source 1 landfill are considered waste samples. The surface and subsurface samples collected from Source 1 represent material used to fill the marsh or landfill wastes and do not represent native soil. Therefore, no background sample is needed to document background concentrations of hazardous substances. However, to document that lead and PCBs are not present at high concentrations or ubiquitous in the area of Source 1, background levels of lead and PCBs thought to be outs ide the

immediate influence of Source 1 have been provided. The background sample results presented in this

HRS documentation record are used to document lead and PCB concentrations in the area of Source 1 and are not necessarily the same matrix (fill) as the Source 1 landfill samples. The background sample results are not provided to document observed contamination (Ref. 1, Table 2-3 and Section 5.0.1).

To determine lead and PCB concentrations in the area of Source 1, soil sampling locations for each investigation conducted at Sauer Dump were reviewed and potential sampling locations outside the

influence of the area thought to be Source 1 were identified . A summary of those sampling locations are provided in the Background Lead and PCB Concentrations Section of this documentation record. Samples located outside the influence of areas thought to be Source 1 were collected in 1992, 1999, and 2007. The locations are provided in References 33 and 48 and are identified as background locations.

The concen trations of lead and PCB detected in the background samples are provided to identify concentrations of lead and PCB in the area surrounding Source 1 and are not provided to document observed contamination (Ref. 1, Table 2-3; Section 5.0.1). Lead and PCBs have been determined to be the primary contaminant s of concern (COC) at the Sauer Dump , and are the only hazardous substances included in this HRS documentation ( Ref. 31, p. 38). However, numerous other hazardous substances including SOVs, VOCs, and metal s other than lead may be associated with Sauer Dump (Ref. 14, pp. 11, 12).

The full extent of Source 1 has not been documented.

BACKGROUND LEAD AND PCB CONCENTRATIONS

1992 Background Soil Sample
- ESI

During the ESI conducted by EPA Region 3 contractors in 1992, a background soil sample (S -12) was collected from the junction of Lynhurst Road and Morse Lane

. The soil collected for the sample w as dark brown, sandy clay loam (Ref. 5, pp. 17, 21, 22 ; Ref. 48 ). The laboratory data validation repo rt for the sample is provided in Section 3 of Reference 5 . The soil sample was analyzed through EPA’s Contract Laboratory Program (CLP) and was analyzed using the CLP statement of work (SOW) for inorganics and organics (Ref. 5, pp. 17, 85, 141, 142 ). Ref erence 16, pages 16 and 17, provides the logbook notes taken during sample collection. The location of S-12 is shown on Reference 5, Figure 2, page 22, and Reference 48. The sampling location is northeast of Source 1. Concentrations of lead and PCBs det ected

in S- 12 are summarized in Table 1.

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22 TABLE 1

1992 SOIL SAMPLE CONCENTRATIONS

Sample ID Sample Type Date Hazardous

Substance Hazardous

Substance

Conc entration

(mg/kg) Detection

Limit *

(mg/kg) Reference

S

- 12 (CHH43) (MCGX41) Soil 12/0 8/1992 Lead 53.2 0.6 5, pp. 29, 345; 16, pp. 17, 18

Aroclor

1242 0.0 47 U 0.0 33 5, pp. 61, 536; 16, pp. 17, 18

Aroclor

1248 0.0 47 U 0.0 33 5, pp. 536; 16, pp. 17, 18

Aroclor

1254 0.0 47 U 0.0 33 5, pp. 61, 536; 16, pp. 17, 18

Aroclor

1260 0.0 47 U 0.0 33 5, pp. 61, 536; 16, pp. 17, 18

Note: All concentrations have been converted to mg/kg.

* The detection limits are contract

- required quantitation limits for organic compounds and contract

- required detection limits for inorganic compounds (Ref

. 5, pp. 345, 536; Ref. 30 ). mg/kg Milligram per kilogram

U Not detected. The associated number indicates approximate sample concentration necessary to be detected (Ref. 5, p.

2 6).

### SD

- Waste Characteristics

23 1999 Background Soil Sample

In 1999, MDE collected a background soil sample (S -9) north of the Sauer Dump (Ref. 29, pp. 3, 8, 13, 15). C oncentrations of lead and PCBs detected in the sample are summarized in the Table 2. S- 9 was sent to the Maryland Department of Health and Mental Hygiene (Ref. 49). PCBs were anal yzed using EPA Method 625 (Ref. 49, p. 1). The inorganic analytical method was not specified in reference documentation (Ref. 49, p. 3). The location of S -9 is shown in Fig ure 3, page 8, of Reference 2 9, and

Reference 48 . The analytical method and date of sample collect ion is not specified in available documentation ( Ref. 29 , pp. 3, 13, 15). A description of the soil sample is not provided in reference

documentation.

TABLE 2

1999 B ACKGROUND SO IL CONCENTRATIONS

Sample ID Sample Type Date Hazardous

Substance Hazardous

Substance

Concentration

(mg/kg) Detection

Limit*

(mg/kg) Reference

S

- 9 Soil 1999 Lead 47.9 mg/kg 0.6 29, p. 13; 49, p. 3

Aroclor

1242 U 0.033 29, p. 15 ; 49, p. 1

Aroclor

1248 U 0.033 29, p. 15 ; 49, p. 1

Aro clor

1254 U 0.033 29, p. 15 ; 49, p. 1

Aroclor

1260 U 0.033 29, p. 15 ; 49, p. 1

Note: All concentrations have been converted to mg/kg.

* The detection limits are c ontract -r equired q uantitation l imits for organic compounds and c ontract -r equired d ete ction

l imits for inorganic compounds (Ref. 49, p. 1 Ref. 30 ). mg/kg Milligram per kilogram

U Not detected above the detection limit (Ref. 5, p. 2 6).

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- Waste Characteristics

24 2007 Background Soil Samples

During the 2007 extent of contamination s tudy conducted by an MDE environmental contractor, 10 soil samples (DG -SS31, DG-SS32, DG-SS25, DG-SS26, DG-SS27, DG-SB02, DGSB03, DG-SB04, DGSB05, and DG- SB06) were collected to evaluate whether the eastern extent of the lead and PCB hot-spot area identified on the Sauer Dump property overlapped onto Parcel 137 located east of Parcel 425, and the

fill area of Source 1 (Ref. 15; Ref. 31 , p. 28

, Figure 7 , p . 79, and Figure 10, p. 82). The sampling locations and concentrations of lead and PCBs detected in the samples are shown on Figure 7 , page 79 and Figure 10, page 82 of Reference 31. The analytical results from five surface soil samples (DG -SS19,

DG -SS20, DG-SS21, DG-SS22, and DG-SS23) are used to document background concentrations of lead

and PCBs. These sampling locations were selected because they are located in the vicinity of Source 1 but are located outside the probable fill area of Source 1 , based on the approximate fill boundaries of Source 1, and are not likely to have been impacted by Sauer Dump (Ref. 15; Ref. 31, Figure 10, p. 82).

Parcel 137 is referred to as the Lusk property in Reference 14 and the location is shown in Reference 14, Volume 2, page 119. The Lusk property is east of Parcel 425 and Source 1. Aerial photographs show that the Lusk property, as well as Sa uer Dump, was created by fill. Sauer Dump was a n emergent
herbaceous wetland prior to being filled ( Ref. 14 , pp. 10, 119; Ref. 61, pp. iii, 1, 2, 10, 11 ). Analytical results from soil samples collected from the Lusk property show lead and PCBs concentrat ions in the fill surrounding Source 1.

The surface soil samples were analyzed for lead in accordance with EPA Method 6010B, and PCBs in

accordance with EPA Method 8082 as stipulated in the EPA-approved remedial action plan ( RAP ) (Ref. 25) and addendums. Subsurface soil samples were analyzed for lead in accordance with EPA Method 6010B, PCBs in accordance with EPA Method 8082, VOCs in accordance with EPA Method 8260B, and SVOCs in accordance with EPA Method 8270C as stipulated in the EPA-approved RAP and addendums. Surface and subsurface soil samples were homogenized after collection by first removing rocks or organic matter and then using the coning and quartering method (American Society for Testing and Materials [ASTM] C702 -80) (Ref. 31, p. 15; Ref. 17, p. 13). The chain -of-custody records for the background samples are presented in Reference 17, page 16. The data validation is provided in Reference 31, Appendix B, page 104. The data review was performed in accordance with the procedures specified i n Appendix E, Quality Assurance Project Plan of the Response Action Plan – Revision 2 (Final) (Ref. 25); EPA Functional Guideline documents for Organic (1999) and Inorganic Data Review (2002); EPA Region III Modifications to National Functional Guidelines for Organic Data Review (S eptember 1994); and quality assurance and control parameters set by the project laboratories ( Ref. 17; Ref. 31, pp. 22,

105 ).

Surface soil samples were collected from under the vegetative mat with a disposable trowel in accordanc e with Standard Operating Procedure ( SOP ) 2 in Appendix A of the Field Sampling Plan (FSP) ( Ref. 24 , p. 11; Ref. 31, p. 15)

. Samples consisted of a three

- point compo s ite of soil collected from approximately 0 to 6 inches bgs, placed on a disposable alumin um tray , and homogenized (Ref. 31, p . 15).

PCB and lead concentrations detected in the background soil samples collected from Parcel 137 are summarized in Table 3 of this documentation record. Background sampling locations are shown in

Reference 33.

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25 TABLE 3

2007 BACKGROUND SOIL C ONCENTRATIONS

Sample ID DG

- SS19

- 0 Sample Type Soil Sample Date 01/11/2007

Hazardous

Substance Hazardous Substance

Conc entration (mg/kg) Sample Quantitation

Limit * ( mg/kg) Reference

Lead 114 J 0. 18 31, pp. 66, 82 ; 17, p p

. 73 , 768

Aroclor 1242 <0.037 U 0.037 31, pp. 66, 82 ; 17, p. 41

Aroclor 1248 <0.037 U 0.037 31, pp. 66, 82 ; 17, p. 41

Aroclor 1254 <0.037 U 0.037 31, pp. 66, 82 ; 17, p. 41

Aroclor 1260 0.041 0.037 31, pp. 66, 82 ; 17, p. 41 Sample ID DG

- SS20

- 0 Sample T ype Soil Sample Date 01/11/2007

Hazardous

Substance Hazardous Substance

Conc entration (mg/kg) Sample Quantitation

Limit * ( mg/kg) Reference

Lead 130 J 0. 21 31, pp. 66, 82 ; 17, p p . 74 , 768

Aroclor 1242 <0.043 U 0.043 31, pp. 66, 82 ; 17, p. 42

Aro clor 1248 <0.043 U 0.043 31, pp. 66, 82 ; 17, p. 42

Aroclor 1254 <0.043 U 0.043 31, pp. 66, 82 ; 17, p. 42

Aroclor 1260 0.036 J 0.043 31, pp. 66, 82 ; 17, p. 42 Sample ID DG

- SS21

- 0 Sample Type Soil Sample Date 01/11/2007

Hazardous

Substance Hazardous Su bstance

Conc entration (mg/kg) Sample Quantitation Limit* ( mg/kg) Reference

Lead 324 J 0. 27 31, pp. 66, 82 ; 17, p p . 75 , 768

Aroclor 1242 <0.056 U 0.056 31, pp. 66, 82 ; 17, p. 43

Aroclor 1248 <0.056 U 0.056 31, pp. 66, 82 ; 17, p. 43

Aroclor 1254 <0.056 U 0.056 31, pp. 66, 82 ; 17, p. 43

Aroclor 1260 0.26 0.056 31, pp. 66, 82 ; 17, p. 43

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- Waste Characteristics

26 TABLE 3 (Continued)

2007 BACKGROUND SOIL C ONCENTRATIONS (Continued)

Sample ID DG

- SS22

- 0 Sample Type Soil Sample Date 01/11/2007

Hazardous

Substance Hazardous Substan ce Conc entration (mg/kg) Sample Quantitation Limit * ( mg/kg) Reference

Lead 140 J 0.54 31, pp. 66, 82 ; 17, p p . 76 , 768

Aroclor 1242 <0.059 U 0.059 31, pp. 66, 82 ; 17, p. 44

Aroclor 1248 <0.059 U 0.059 31, pp. 66, 82 ; 17, p. 44

Aroclor 1254 <0.059 U 0.0 59 31, pp. 66, 82 ; 17, p. 44

Aroclor 1260 0.14 0.059 31, pp. 66, 82 ; 17, p. 44 Sample ID DG

- SS23

- 0 Sample Type Soil Sample Date 01/11/2007

Hazardous

Substance Hazardous Substance

Conc entration (mg/kg) Sample Quantitation Limit * ( mg/kg) Reference

Lea d 205 J 0.48 31, pp. 66, 82 ; 17, p p . 7 7, 768

Aroclor 1242 <0.053 U 0.053 31, pp. 66, 82 ; 17, p. 45

Aroclor 1248 <0.053 U 0.053 31, pp. 66, 82 ; 17, p. 45

Aroclor 1254 0.051 J 0.053 31, pp. 66, 82 ; 17, p. 45

Aroclor 1260 0.12 0.053 31, pp. 66, 82 ; 17, p. 45

Notes: All concentrations have been converted to mg/kg.

* As documented in Reference 52, the reporting limits provided in Reference 17 are equivalent to the sample quantitation

limi ts. Reference 52 calculates the sample quantitation limits for several samples results in Reference 17. As documented in Reference 52, the sample quantitation limits are equal to the reporting limits. Therefore, the reporting limits are equivalent to the sample quantitation limit. The non sample specific method detecti on limit for lead is 0.30 mg/kg and for PCBs is 0.033 mg/kg (Ref. 17, pp. 60, 84).

J The reported value is an e stimate (Ref. 17, pp. 5, 45). mg/kg Milligram per kilogram

SS Surface soil

U Analyte not detected (reporting limit presented)

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- Waste Characteristics

27 LEAD AND PCB BACKGROUND CONCENTRATIONS

The highest background lead and PCB concentrations are summarized in Table 4. These concentrations represent concentrations of lead and PCB in the area of Source 1 and are not used to establish observed

contamination . The conce ntrations are included to provide evidence that the lead and PCB concentrations in Source 1 samples are higher than the concentrations found in the area of the source.

TABLE 4

HIGHEST LEAD AND PCB BACKGROUND CONCENTRATIONS

Sample Identification Hazardo us Substance Hazardous

Substance

Concentration Reference

DG

- SS21

- 0 (2007) Lead 324 J mg/kg See Tables 1 through

3 of this

documentation record

All background samples Aroclor 1242 < 0. 059 See Tables 1 through

3 of this

documentation record

All backg round samples Aroclor 1248 < 0. 059 See Tables 1 through

3 of this

documentation record

All background samples Aroclor 1254 < 0. 059 See Tables 1 through

3 of this

documentation record

DG

- SS21

- 0 Aroclor 1260 0.26 mg/kg See Tables 1 through

3 of this

document ation record

Notes: All concentrations have been converted to mg/kg.

J Estimated concentration mg/kg Milligrams per kilogram

### SD

- Waste Characteristics

28 SOURCE 1 SAMPLES

Source 1 landfill samples were collected during numerous investigations, including investigations conducted in December 2001, June 2002, and January 2007. Analytical results from the landfill samples collected during these investigations are used to characterize Source 1. The landfill sample analytical results from these investigations document concentrations of lead and PCBs above background lead and PCB levels. The sections below describe the landfill sampling activities and locations, and summarize constituent concentrations detected in the landfill samples. Source 1 sampling location s are shown in

Referen ce 33.

The samples collected from Source 1 have been described as surface soil, subsurface soil, and fill material in reference documentation. Because Source 1 includes a filled marsh (landfill), all samples collected from Source 1 (landfill) are conside red waste samples. Although reference documentation text describes the samples as surface and subsurface soil, all samples collected from Source 1 are considered waste samples. The surface and subsurface samples collected from Source 1 represent material used to fill the marsh or landfill wastes, and do not represent native soil. Therefore, no background sample is needed to document background concentrations of hazardous substances. However, to document that lead and PCBs are not present at high concent rations or ubiquitous in the area of Source 1, background concentrations of lead and PCBs have been provided in Table 4 of this documentation record. The background samples presented in this HRS documentation record are used to document lead and PCB

conce ntrations in the area of Source 1 and are not necessarily the same matrix (fill) as the landfill samples.

December 2001
- Source 1 Samples

On December 12, 2001, five surface samples were collected from Source 1 by a MDE environmental

consultant. S ampl es were collected from a depth of 4 to 5 inches bgs from locations within Source 1.

Surface sampl ing locations were chosen to evaluate two areas of Source 1 where prior sampling did not appear to have been performed. The samples were submitted for analys is to Envirosystems, Inc., in Columbia, Maryland. The samples were analyzed for the following constituents: VOCs using EPA Method 8260; SVOCs using EPA Method 8070; total metals using EPA Methods 200 series and 335.3; and pesticides and PCBs using EPA Met hod 8081/8082. All sampling was conducted according to site

specific quality assurance and quality control ( QA/QC ) guidelines ( Ref. 14, pp. 13

, 97, 202, 206 ). The sampling and analysis plan for the sampling event is provided as Reference 57

. The surface samples were collected within the fill area of Source 1 and are therefore considered waste samples (Ref. 15; Ref. 14, p. 97).

On December 11 and 12, 2001, a backhoe was used to excavate nine test pits on site to either the water

table or to native soil . The test pit locations were chosen to evaluate features at Sauer Dump that indicated the potential presence of hazardous substances. Features were observed on aerial photographs, identified during earlier investigation s, and/or depicted on topographic maps of Source 1 . The depths of the test pits ranged between 3.5 and 11.5 feet bgs . Miscellaneous debris including wood, plastic, metal, rubber, brick, sand, blank sand/soil, concrete/concrete castings, asphalt, ash, electrical parts, paint/paint containers, batteries, crushed drums, railroad ties, styrofoam, and a white/gray powdery substance was observed in all of the test pits. The fill was observed to extend below the water table in seven of the nine test pits. Subsurface samples were collected from depths ranging from 3.5 to 11.5 feet bgs (Ref. 14, pp.

13 to 14).

### SD

- Waste Characteristics

29 Between December 19 and 20, 2001, well borings were advanced to depths between 9.5 to 14 feet below

the water table. Miscellaneous debris (wood, plastic, metal, wire, rubber, brick, sand, rock fragments/gravel, glass, concrete, asphalt, ceramic tile, mattress pieces, and paper) in the soil was observed in all of the well borings. The fill was observed to extend below the water table in four of the five well borings. Samples were collecte d from near the top of the area of native soil because of poor sample recovery ; the amount of fill recovered from the borings was not adequate for laboratory analysis. The subsurface samples were collected from depths ranging between 8 and 15 feet bgs (Re f. 14, p. 14).

Available descriptions of the source samples are summarized in Table 5. Source sampling locations are

shown in Reference 33 and in Reference 14, Figure 3 , page 97. The lead and PCB concentrations detected in the Source 1 samples are sum marized in Table 6.

TABLE 5

DESCRIPTION OF 2001 SOURCE 1 SAMPLES

Sample

Identification (depth) Date Sampled Sample Type Sample Depth (below ground surface) Sample Description Reference

SS

- 1 12/12/2001 Waste 4 to 5 inches None 14 , pp. 13 , 37, 97

SS

- 3 12/12/2001 Waste 4 to 5 inches None 14 , pp. 13 , 37, 97

SS

- 5 12/12/2001 Waste 4 to 5 inches None 14 , pp. 13 , 37, 97

TP -1 (3.5) 12/11/2001 Waste 3.5 feet Fill 14 , pp. 13, 14, 44, 97, 127

TP -2 (4) 12/11/2001 Waste 4 feet Fill 14 , pp. 13, 14, 44, 97, 128

TP -3 (6.75) 12/11/2001 Waste 6.75 feet Fill 14 , pp. 13, 14, 44, 97,129

TP -6 (7.5) 12/12/2001 Waste

7.5 feet Fill, white gray powdery

substance 14, pp. 13, 14, 44, 97, 134

TP -7 (5) 12/11/2001 Waste 5 feet Fill, black sand 14 , pp. 13, 14, 44, 97, 135

TP -9 (10) 12/11/2001 Waste 10 feet Fill 14 , pp. 13, 14, 44, 97, 140

MW -1 (8 -12 f eet ) 12/20/2001 Waste 8-12 feet Organic silt with clay and organic matter, clay 14, pp. 14, 50, 97, 142

MW -4 (11-12 f eet ) 12/19/2001 Waste

11-12 feet Clay silt, organic fragmen ts 14, pp. 14, 50, 97, 146

Notes:

MW Monitoring well

SS Surface soil s
TP Test pit

### SD

- Waste Characteristics

30 TABLE 6

2001 SOURCE 1 SAMPLES

– LEAD AND PCB CONCENTRATIONS

Sample

Identification (inches below grade unless otherwise noted) Hazardous

Substance Concentration (mg/kg) Q S ample Quantitation

Limits* (mg/kg) (Ref. 52 , p. 1 ) Date Reference

Polychlorinated Biphenyls

SS

- 1 Aroclor 1254 1.9 D 0.3 4 12/12/2001 14 , pp. 38, 3 71 , 39 4

SS

- 3 Aroclor 1254 4.8 D 0. 20 12/12/2001 14 , pp. 38, 37 3, 394

SS

- 5 Aroclor 1260 0.85 0.04 2 12/12/20 01 14 , pp. 38, 37 6, 394

TP

- 1 (3.5) Aroclor 1254 72 D 4.6 12/11/2001 14 , pp. 44, 35 5, 393

TP

- 1 (3.5) Aroclor 1260 43 D 4.6 12/11/2001 14 , pp. 44, 35 5, 393

TP

- 2 (4) Aroclor 1254 84 D 2.7 12/11/2001 14 , pp. 44, 35 7, 393

TP

- 3 (6.75) Aroclor 1254 800 D 24 1 2/11/2001 14 , pp. 44, 35 9, 393

TP

- 6 (7.5) Aroclor 1242 8.8 D 0.85 12/12/2001 14 , pp. 44, 36 5, 393

TP

- 6 (7.5) Aroclor 1248 9.1 D 0.85 12/12/2001 14 , pp. 44, 36 5, 393

TP

- 7 (5) Aroclor 1248 1.3 D 0.08 1 12/12/2001 14 , pp. 44, 364 , 393

TP

- 9 (10) Aroclor 125 4 3.7 D 0. 29 12/11/2001 14 , pp. 44, 36 9, 393

MW

- 1 (8

- 12 f eet ) Aroclor 1254 0.60 0.097 12/20/2001 14 , pp. 50, 48 9 , 5 23

MW

- 4 (11 to 12

f eet ) Aroclor 1242 0.19 0.047 12/19/2001 14, pp. 50, 492, 523

Metals

Sample

Identification Hazardous

Substance Concen tration (mg/kg) Q Sample Quantitation

Limit * (mg/kg) (Ref. 52, p. 1) Date Reference

TP

- 1 (3.5) Lead 3,000 mg/kg 14.49 12/11/2001 14 , pp. 43, 3 81 , 393

TP

- 2 (4 feet ) Lead 4,100 mg/kg 15.87 12/11/2001 14 , pp. 43, 3 82 , 393

TP

- 4 (11.5) Lead 940 mg/kg 12.5 0 12/11/2001 14 , pp. 43, 38 3 , 393

Notes: All concentrations have been converted to mg/kg.

* The sample quantitation limits are provided in Reference 52. mg/kg Milligrams per kilogram

D Sample diluted and reanalyzed

MW Monitoring well Q Analytical data q ualifier

SS Surface soil

TP Test pit

### SD

- Waste Characteristics

31 December 2001
- Source 1 Sampl es (Continued)

Lead concentrations detected in samples collected from Source 1 in 2001 ranged from 940 to 4,100 mg/kg, which are concentrations significantly higher than the highest bac kground lead level of 324 mg/kg (Tables 4 and 6 of this documentation record). PCBs were detected in every test pit and monitoring well subsurface soil sample at concentrations above background PCB levels (Ref. 14, p p. 43-44; Tables 4 and

6 of this docume ntation record). PCBs are not naturally; therefore, elevated concentrations detected below the ground surface are attributed to an underground source of PCB, such as the waste deposited at Sauer Dump (Ref. 20, p. 1).

June 2002 - Grid Sampling
- Source 1 Samples

In June 2002, additional investigations were conducted at the Sauer Dump to further identify and

delineate areas with PCB concentrations exceeding 100 mg/kg (Ref. 14, p. 17). Two s am pling grids were

established on Source 1 at the location of t wo known PCB hot spots (Ref. 15; Ref. 14, Figure 7, p. 101). The locations of the grids are shown on Figure 7, page 101, of Reference 14 . A grid interval of 3 meters

was chosen for each sampling grid. The first grid was centered over test pit ( TP )-1 and included nine sampling points. The dimensions of the grid were 6 m eters by 6 m eters. The four corners of the grid were surveyed. The second grid was arranged to include TP-2 and TP-3 where previous analytical results

indicated total PCB concentrations of 84 and 800 mg/kg , respectively. The second grid was expanded to include areas where analytical results from samples collected during previous investigations (S-2 collected in 1990, S-2 collected in 1999, S-3/10 collected in 1999, and S-9 collected in 1992) indicated

total PCB concentrations of 1 10, 85, 81, and 150 mg/kg , respectively. The dimensions of the second grid

were 42 m eters by 18 m eters and included 105 sampling points. The four corners and two mid-points of this grid were surveyed (Ref. 14, p. 18)

.

Test pits were chosen as the means for collecting both surface and subsurface samples from Source 1. The test pits provided increased visual access to the subsurface material . Between June 5 and 11, 2002 , a total of 114 test pits were excavate d using backhoes to the depth of the water table (2 to 10 feet bgs ). One composite surface sample was c ollected from each test pit between the depths of 0 to 2 feet . One composite subsurface sample was collected from depths between 2 and 4 feet in test pits where the depth to ground water exceeded 2 feet. A second subsurface sample was composited from each test pit between the depths of 4 feet and in test pits where the depth to ground water exceeded 4 feet ( Ref. 14 , p. 18).

A transformer

- like object was encountered at sampling location G -6 and an off- white oily fluid was observed leaking from the object. Samples of the fluid and fill/soil immediately under the object were

collected

. This sample appears to be sample G -6 (4

- 5 feet)

, which contains 33, 000 mg/kg of Aroclor 1254 (Ref. 14, pp. 18, 70, 719). (The Form I for the sample G-6 [4-5 feet] could not be found in Reference 14.) During the June 2002 sampling event, a total of 285 fill samples and one fluid sample were collected (Ref. 14, p. 18). T he samples were screened using an immunoassay screening analysis.

Based on the results of the screening , 30 samples were selected for PC B analysis by Envirosystems using EPA Method 8082 (Ref. 14, p. 19). The PCB a nalytical results from these samples are summarized in

T able 7. The concentrations in Table 7 are significantly above the background PCB concentrations listed in Table 4 of this documentation record. An illustration of the sampling grid showing the sampling locations is provided in Reference 14, Figure 16, page 110, and summarized in Reference 33. Descriptions of the samples collected in 2002 are not provided in reference documentation. The samples are considered waste samples because the samples were collected from within the area of the fill (Source 1) (Ref. 15; Ref. 33).

### SD

- Waste Characteristics

32 TABLE 7

2002 SOURCE 1 SAMPLES

PCB CONCENTRATIONS

Sample

Identification (feet below grade) Hazardous

Substance Concentra tion (mg/kg) Q SQL( mg/kg ) (Ref. 52, pp. 1, 2) Date Reference

J

- 13 (0

- 2) Aroclor 1254 105 D 6.95 0 6/05/2002 14 , pp. 67 8 , 71 7

G

- 6 (4

- 7) Aroclor 1254 3,900 D 173.68 06/11/2002 14 , pp. 67 9 , 71 7

G

- 7 (4

- 6) Aroclor 1254 100 D 6.95 06/11/2002 14 , pp. 6 80 , 71 7

I

- 11 (2

- 4) Aroclor 1254 400 D 17.37 06/06/2002 14 , pp. 6 81 , 71 7

G

- 7 (2

- 4) Aroclor 1254 370 D 17.3 7 06/11/2002 14 , pp. 6 82 , 71 7

A

- 3 (2

- 3) Aroclor 1254 1.2 D 0.35 06/05/2002 14 , pp. 6 83 , 71 7

D

- 4 (0

- 2) Aroclor 1254 330 D 17.55 06/10/2002 14 , pp. 6 84 , 71 7

I

- 12 (0

- 2) Aroclor 1254 4,600 D 173.68 06/05/2002 14 , pp. 6 85 , 71 7

I

- 12 (2

- 4) Aroclor 1254 1,500 D 69.47 06/05/2002 14 , pp. 68 6 , 71 7

F

- 7 (4

- 6) Aroclor 1254 39 D 3.47 06/11/2002 14 , pp. 68 7 , 71 7

I

- 13 (2

- 4) Aroclor 1254 240 D 17.37 06/05/2002 14 , pp. 68 8 , 71 7

G

- 11 (0

- 2) Aroclor 1254 3.2 D 0.87 06/07/2002 14 , pp. 68 9 , 71 7

F

- 7 (0

- 2) Aroclor 1254 410 D 34.74 06/11/2002 14 , pp. 6 90, 71 7

E

- 8II (0

- 2) Aroclor 1254 420 D 34.74 06/11/2002 14 , pp. 6 91 , 71 8

G

- 6 (0

- 2) Aroclor 1254 97 D 6.95 06/11/2002 14 , pp. 6 92 , 71 8

H

- 10 (0

- 2) Aroclor 1254 390 D 34.74 06/11/2002 14 , pp. 6 93 , 71 8

I

- 8 (0

- 2) Aroclor 1254 580 D 34.74 06/11/2002 14 , pp. 6 94 , 71 8

E

- 8II (2

- 4) Aroclor 1254 3 10 D 27.79 06/11/2002 14 , pp. 6 95 , 71 8

D

- 8 (2

- 4) Aroclor 1254 13 D 1.74 06/07/2002 14 , pp. 69 6 , 71 8

Notes: All concentrations have been converted to mg/kg.

D Sample diluted and reanalyzed mg/kg Milligram per kilogram SQL Sample quantitation limit

### SD

- Waste Characteristics

33 SOURCE SAMPLES (Continued)

January 2007 - Source 1 Samples

During the 2007 extent of contamination s tudy , 32 surface soil and nine subsurface soil samples were

collected from January 8 through 24, 2007. The surface soil samples were analyzed for lead in

accordance with EPA Method 6010B and PCBs in accordance with EPA Method 8082 as stipulated in the

EPA -approved RAP ( Ref. 2 5, pp. 37, 49; Ref. 31, pp. 14-15) and addendums. Subsurface soil sampl es were analyzed for lead in accordance with EPA Method 6010B, PCBs EPA Method 8082, VOCs in

accordance with EPA Method 8260B, and SVOCs in accordance with EPA Method 8270C as stipulated in the RAP and addendums. Surface and subsurface samples were homoge nized after collection by first removing rocks or organic matter and then using the coning and quartering method (ASTM method C702-80) (Ref. 31, pp. 14, 15)

.

Surface samples were collected from under the vegetative mat with a disposable trowel in accord ance with SOP 2 in Appendix A of the FSP ( Ref. 24 , Appendix A, p. 11). Samples included a three -point composite from approximately 0 to 6 inches bgs and were placed on disposable aluminum trays and homogenized (Ref. 31, p 15).

Subsurface samples were col lected by driving a 5-foot core sampler with a sledgehammer or by hydraulically driving the core sampler with a drill rig. The core was a 1.5-inch- diameter , hollow

stainless

- steel probe rod that contain ed a clean acetate sampling tube for collection of so il samples. The samples collected via drill rig were collected in accordance with SOP 4 in the FSP (Ref. 24 , Appendix A, p. 31). The 2 - to 3-foot sample interval was then placed on a disposable aluminum tray, homogenized, and then transferred to sample containers to be submitted for lead and PCB analy sis (Ref. 31, p. 15).

The chain -of- custody records for the samples are presented in Reference 17, page 15; Reference 18, page 7; Reference 50, page 7; and Reference 51, pages 8 and 9. The data validation report is provided in Reference 31, Appendix B, page 104 (Ref. 31, p. 21). Source sampling locations are shown in Reference 31, Figure 6, page 78, and Figure 7, page 79 and Reference 33. Descriptions of the surface samples are not provided in reference d ocumentation. Table 8 provides descriptions of the subsurface samples. Table 9 summarizes the concentrations of PCBs and lead detected in the source samples collected in 2007.

TABLE 8

DESCRIPTION OF 2007 SOURCE 1 SAMPLES

Sample

Identification Date

S ampled Sample Type Sample Depth Sample Description Reference

DG

- SB01 -02 01/24/2007 Waste 2-3 Fill, silty clay, brick, crushed stone, concrete, twigs 31, pp. 22, 67,

93

DG

- SB02 -02 01/24/2007 Waste 2-3 Fill, brick, crushed stone, concrete, plastic pieces 31, pp. 22, 67,

94

DG

- SB03 -02 01/24/2007 Waste 2-3 Fill, rock fragments, brick, clayey silt, roots, sand 31, pp. 22, 67,

95

DG

- SB04 -02 01/24/2007 Waste 2-3 Fill, brick, glass, crushed stone, concrete, silt, sand 31, pp. 22, 67,

96

Notes: Sample depth is in feet below ground surface

. SB S oil boring

### SD

- Waste Characteristics

34 TABLE 9

2007 SOURCE 1 SAMPLES

Sample

Identification Hazardous

Substance Concentration (mg/kg) SQL ( mg/kg) (Ref. 52, pp. 3, 4) Date Reference

Surface Samples

DG

- SS01 -0 Aroclor 1254 1.0 0.041 01 /0 8/2007 31, pp. 65, 78; 18, pp. 6, 7, 14

DG

- SS01 -0 Aroclor 12 60 0.62 0.041 01 /0 8/2007 31, pp. 65, 78; 18, pp. 6, 7, 14

DG

- SS02 -0 Aroclor 1254 0.59 0.041 01/10/2007 31, pp. 65, 78; 17, pp. 14, 15, 32

DG

- SS02 -0 Aroclor 12 60 0.74 0.041 01/10/2007 31, pp. 65, 78; 1 7, pp. 14, 15, 32

DG

- SS03 -0 Aroclor 1254 7.7 0.41 01 /0 9/2007 31, pp. 65, 78; 18, p. 6, 7, 15

DG- SS04 -0 Aroclor 1254 1.4 0.038 01 /0 9/2007 31, pp. 65, 78; 18, pp. 6, 7, 16

DG- SS04 -0 Aroclor 12 60 0.720 0.038 01 /0 9/2007 31, pp. 65, 78; 18, pp. 6, 7, 16

DG- SS05 -0 Aroclor 12 60 1.2 0.043 01/10/2007 31, pp. 65, 78; 17, pp. 14, 15, 33

DG- SS06 -0 Aroclor 1254 0.62 0.038 01 /0 9/2007 31, pp. 65, 78; 18, p. 6, 7, 17

DG- SS06 -0 Aroclor 12 60 0.38 0.038 01 /0 9/2007 31, pp. 65, 78; 18, p. 6, 7, 17

DG- SS07 -0 Aroclor 1254 0.72 0.044 01 /0 9/2007 31, pp. 65, 78; 18, p. 6, 7, 18

DG- SS07 -0 Aroclor 12 60 0.36 0.044 01 /0 9/2007 31, pp. 65, 78; 18, p. 6, 7, 18

DG- SS08 -0 Aroclor 1254 0.65 0.051 01 /0 9/2007 31, pp. 65, 78; 18, p. 6, 7, 19

DG- SS08 -0 Aroclor 12 60 0.37 0.051 01 /0 9/2007 31, pp. 65, 78; 18, p. 6, 7, 19

DG- SS24 -0 Lead 2,720 2.2 01/23/2007 31, pp. 66, 78; 50, p. 6, 7, 28, 790

DG- SS24 -0 Aroclor 1254 48 4.85 01/23/2007 31, pp. 66, 78; 50, p. 6, 7, 13

Subs urface Samples

DG

- SB01 -2 Lead 626 0.7 01/24/2007 31, pp. 67, 79; 51, pp. 7, 8, 123, 1572

DG

- SB01 -2 Aroclor 1254 0.71 L 0.039 01/24/2007 31, pp. 67, 79; 51, pp. 7, 8, 104, 1572

### SD

- Waste Characteristics

35 TABLE 9 (Continued)

2007 SOURCE 1 SAMPLES

Sample

Identification Hazardous

Substance Concentration (mg/kg) SQL ( mg/kg) (Ref. 52, pp. 3, 4) Date Reference

Subs urface Samples

DG

- SB01 -2 Aroclor 1260 0.63 L 0.039 01/24/2007 31, pp. 67, 79; 51, pp. 7, 8, 104, 1572

DG

- SB02 -2 Lead 13,100 22.72 01/24/2007 31, pp. 67, 79; 51, pp. 7, 8, 124, 1572

DG

- SB02 -2 Aroclor 1254 1.6 0.050 01/24/2007 31, pp. 67, 7 9; 51, pp. 7, 8, 105, 1572

DG

- SB02 -2 Aroclor 1260 0.64 0.050 01/24/2007 31, pp. 67, 79; 51, pp. 7, 8, 105, 1572

DG

- SB03 -2 Lead 752 0.62 01/24/2007 31, pp. 67, 79; 51, pp. 7, 8, 125, 1572

DG

- SB04 -2 Lead 770 1 01/24/2007 31, pp. 67, 79; 51, pp. 7, 9, 126, 1572

DG

- SB04 -2 Aroclor 1254 0.35 0.057 01/24/2007 31, pp. 67, 79; 51, pp. 7, 9, 107, 1572

DG

- SB04 -2 Aroclor 1260 0.20 0.057 01/24/20070 31, pp. 67, 79; 51, pp. 7, 9, 107, 1572

Notes: All concentrations have been converted to mg/kg.

mg/kg Milligram s per kilogram

L Estimated low

MDL Method diction limit SQL Sample quantitation limit

SB Subsurface sample, sampling depth 2 to 3 feet below ground surface

SS Surface sample, sampling depth 0 to 6 inches below ground surface (Ref. 31, p. 15)

OTHER INVESTIGATIONS

Source 1 samples were collected during several previous investigations conducted at Sauer Dump. Analytical results from these investigations identify lead and PCBs in source samples. Analytical data are summarized in the sections below to provide additional evidence supporting the presence of lead and

PCBs in Source 1. The data are not used to characterize Source 1.

1986 SI Sample Results

Analytical results of samples collected by EPA Region 3’s FIT during an SI in 1985 provide eviden ce supporting that hazardous substances were disposed in Source 1. The sampling locations are shown on Figure 3 of Reference 6 , page 73 . Table 10 summarizes the hazardous substances detected at Source 1 during the 1985 sampling event. All samples collected during the SI were sent to laboratories contracted

under the CLP for target compound list (TCL) organics and target analyte list (TAL) inorganics analyses (Ref. 6, Section 6).

### SD

– Waste Characteristics

36 TABLE 10

1986 SI SAMPLE RESULTS

Hazardous Substance Sample

Identificatio n Concentration (mg /kg) * CRQL (m g/kg) Reference

Polychlorinated biphenyls

Aroclor 1254 S-4 1.452 0.033 6, p. 6-1B

S-5 4.557 0.033 6, p. 6-1B

S

- 6 2

. 056 0.0 33 6, p. 6

- 1B

S-7 3.305 0.033 6, p. 6-1B

Notes: All concentrations have been converted to mg /kg.

m g/kg Mi lligrams per kilogram *CRQL Contract

- required quantitation limit (Ref. 30)

1992 ESI Sampl ing Results

During the 1992 ESI, soil samples were collected f ro m the Sauer Dump property. The soil sampling locations are shown in Figure 2-1, p. 22 of Reference 5. Background soil sample S-12 was collected to establish background concentrations. Aroclor 1254 was detected in soil samples S -6 at 0.320 m g/kg, S -8

at 39 m g/kg, S -9 at 150 m g/kg, S -10 at 1.1 mg/kg, and S-11 at 0.480 mg/kg. Aroclor 1254 was not detected in the background soil sample S-12 (Ref. 5, pp. 21, 22, Section 3.0, p. 61; Ref. 30). The soil samples were sent to laboratories contracted under EPA’s CLP for TCL organics and TAL inorganics analyses (Ref. 5, p. 85).

During thi s investigation, the contractor observed large quantities of debris on the ground surface including scrap metal, concrete piping, broken concrete and asphalt, railroad ties, treated lumber, wire, and cable; 12 rusty 55-gallon drums in various locations; a sulfide -type odor at various locations; and an oily sheen on surface water (Ref. 5, p. 24).

### SD – Was te Characteristics

37 1999 MDE Sample Results

In late 1999, MDE collect ed eight surface soil samples, one background surface soil sample, and two subsurface soil samples from Saue r Dump (Ref. 29, pp. 3, 8, 9, 13). The sampling locations are shown on Figures 3, 4, and 5, pp. 8, 9, and 10, of Reference 29 . The samples were sent to a CLP laboratory for VOC, SVOC, pesticides/PCB

, and inorganics analys e s ( Ref. 29, pp. 12 to 20). Tabl es 11 and 12 summarize the hazardous substances detected at Source 1 during this sampling event. To identify

concentrations significantly above background levels, the soil concentrations detected were compared to the concentrations detected in background soil sample S -9 (Ref. 29 , p. 8 ).

TABLE 11

1999 SOIL SAMPLE PCB ANALYTICAL RESULTS

Hazardous Substance Sample

Identification Concentration (m g/kg) CRQL (m g/kg) Reference

Polychlorinated biphenyls

Aroclor 1254 S-1 25.94 0.033 29, p. 15

S-2 84.78 0.033 29, p. 15

S-4 16.60 0.033 29, p. 15

S-5 13.20 0.033 29, p. 15

S-8 0.700 0.033 29, p. 15

S-10 32.00 0.033 29, p. 15

S-11 17.70 0.033 29, p. 15

S-12 7.90 0.033 29, p. 15

Aroclor 1260 S

- 11 11

. 13 0.0 33 29, p. 15

Notes:

All concentrations have been converted to mg/kg. CRQL Contract

- required quantitation limit (Ref. 30, p. 3)

m g/kg Mi lli grams per kilogram

S Soil

### SD – Was te Characteristics

38 TABLE 12

1999 SOIL SAMPLE LEAD ANALYTICAL RESULTS

Hazardous

Substance Evidence Concentration (mg/kg) Background

Concentration ( mg/kg)

(S

- 9) CRDL (Ref. 30, p. 2) (mg/kg) Reference

Metals

Lead S-1 1,409 47.9 0.6 29, p. 13

S-2 5,944 47.9 0.6 29, p. 13

S-3 2,232 47.9 0.6 29, p. 13

S-4 1,407 47.9 0.6 29, p. 13

S-11 831 47.9 0.6 29, p. 13

S-12 2,283 47.9 0.6 29, p. 13

Note s: CRDL Contract

- required detection limit mg/kg Milligrams per kilogram

S Surface soil

2004 and 2005 Remedial Investigation

As part of the remedial investigation/feasibility study ( RI/FS ), soil sampling activities were conducted in January 2004 ( Ref. 14 , pp. 19, 21) and March 2005 ( Ref. 14, p. 20) at the Sauer Dump property. Analytical results from these sampling events were not used to characterize Source 1 because the laboratory data reports for these investigations could not be located to be used a s a reference for this

documentation record

.

### SD – Hazardous Waste Quantity

39 2.4.2 Hazardous Waste Quantity

2.4.2.1.1 Hazardous Constituent Quantity

Hazardous Substance Constituent Quantity (pounds) Reference

The information available is not sufficient to adequately support the ev aluation of the hazardous constituent quantity for Source No. 1.

Sum (pounds): Unknown Hazardous Constituent Quantity Value (C): N ot available

2.4.2.1.2 Hazardous Wastestream Quantity

Hazardous Substance Quantity (pounds) Reference

The information ava ilable is not sufficient to adequately support the evaluation of the hazardous wastestream quantity for Source No. 1.

Sum (pounds) : Unknown Hazardous Wastestream Quantity Value (W): N ot available

2.4.2.1.3 Volume

The information available is not sufficient to adequately support the evaluation of the volume for Source

No. 1.

Dimension of source (yd 3 or gallons): Unknown Volume Assigned Volume: N ot available

2.4.2.1.4 Area

As documented in Tables 6, 7, and 9 of this documentation record, analytical res ults of samples collected from Source 1 revealed the presence of lead and PCBs. Source 1 is estimated to cover at least 2.48 acres, which is the area of Parcel 425 on which the fill is located (Ref. 15; Ref. 14, pp. 9, 96). The area of the

fill has been estimated from elevations on Sauer Dump and is shown in Reference 15. Therefore, the area

of Source 1 is estimated to be at least 2.48 acres, or 108 ,028.8 ft 2

. The source type is ‘ Landfill’ , so the area value is divided by 3,400 to obtain the assigned va lue, as shown below (Ref. 1, p. 51591, Table 2-5).

Dimension of source (ft 2 ): 108,028.8

Area (A) Assigned Value: 108,028.8/3,400 = 31.77

2.4.2.1.5 Calculation of a Source Hazardous Waste Quantity (HWQ) Value

The source area HWQ for Source 1 is assigned a value of 31.77 (Ref. 1, Section 2.4.2.1.5 ).Summary of Sources Evaluated



### 40 SUMMARY OF SOURCES EVALUATED

Source

No. Source Name Source Hazardous Waste Quantity

Value Source Containment Values

Ground

Water Surface

Water Air

Gas Air

Particulate

1 Landfill 31.77 NS 10 NS NS

Notes:

NS Not Scored Total Source Hazardous Waste Quantity Value: 31.77 (Ref. 1, Section 2.4.2.2)

### SWOF - Surface Water Overland Flow/Flood Migration Pathway

41 4.0 SURFACE WATER MIGRATION PATHWAY

4.1 Overland/Flood Migration Component

4.1.1.1 Definition of Hazardous Substance Mig ration Path for Overland/Flood Component

Prior to being filled with waste materials as part of landfill activities

, the Sauer Dump area was undeveloped woodland and wetland containing a natural drainage channel. A finger of a natural drainageway trend ing northwest-southwest was present across the Sauer Dump area. This drainage

system was occupied by an emergent herbaceous wetland that extended across the area and carrie d runoff

from the area directly into the Back River (Ref. 61, pp. 1, 10, 11). A 2012 hi storical aerial photography study completed for the property documents land filling of these wetlands (Ref. 61

, p. iii ).

During the 1986 SI completed at Sauer Dump, EPA Region 3 observed wetlands flowing from east to west along the northern border of Sou rce 1. This wetland area was located approximately 40 feet north of the former drum storage area, as described in Reference 6 . A small pond was observed within these

wetlands. The wetlands were observed to discharge directly into the Back River (Ref. 6, p. 9 and Figure 2, p. 72 ).

During the 1992 ESI, a wetland delineation was completed at Sauer Dump (Ref. 5, p. 74). The

delineation was conducted using the Federal Manual for Identifying and Delineating Jurisdictional
Wetlands, was verified using the 1 987 U.S. Army Corps of Engineers’ (USACE) Wetland Delineation

Manual and the delineated wetlands were determined to meet HRS requirements

. Five palustrine and three estuarine wetlands were identified on Sauer Dump (Ref. 5, pp. 74 and 78 ). The wetlands we re identified along the eastern, southern, western, and northwestern borders of Source 1 (Ref. 5, p. 78; Ref. 8; Ref. 34 ). At the time of the 1992 wetland delineation , all of these wetlands were connected by drainage channels that were also identified as wetlands (Ref. 5, pp. 74 to 85 ).

A second wetland delineation was performed on Sauer Dump in 2002. The information gathered during the 2002 delineation was consistent with the information found during the 1992 delineation. Th e 2002 delineation documented the presence of two unconnected parcels of wetlands. Figure 5, page 99, of Reference 14 shows the two distinct wetland areas, the 25 -foot buffer zone surrounding the non- tidal wetland areas, and the high water marks associated with the pond northwest of Source 1 and Back River

located south of Source 1. The 2002 delineation identified Wetland #1 as a small isolated non

- tidal wetland covering 0.7 acre surrounding a pond that is north of Source 1. Wetland #2 is identified as a larger wetland area cover ing 1.39 acres. Reference documentation divides Wetland #2 into three areas: the Southwest Finger, the Back River Shoreline Area, and the Southeast Finger. Wetland #2 is comprised of a tidal wetland area along the shoreline (below the high water mark) a nd non

- tidal wetland areas in the Southwest Finger and the Southeast Finger (above the high water mark) ( Ref. 14

, p. 16 and Appendix E, p. 150).

The 2002 wetland delineation was completed using the methodology contained in the revised 1987

USACE’s Wetlan d Delineation Manual (subsequently referred to as 1987 Manual), and other related guidance documents and the delineated wetlands were determined to meet HRS requirements (Ref. 14, p. 151).

A third wetland delineation was performed at Sauer Dump in 2012 (R ef. 62, p. 1). The 2012 wetland

### SWOF - Surface Water Overland Flow/Flood Migration Pathway

42 delineation was performed using the USACE 2010 Interim Regional Supplement to the Corps of Engineers Wetland Delineation Manual; Atlantic and Gulf Coastal Plain Region (Version 2.0) and the delineated wetlands were determined to meet HRS requirements (Ref. 62, pp. 6, 11). The results of this

2012 delineation were generally consistent with and confirmed the results of the 2002 delineation, with slight adjustments to the boundaries of the wetlands that did not result in a cha nge to HRS factor values (Ref. 14, p. 163; Ref. 34; Ref. 62, pp. 1, 8 to 10, 17). The 2012 wetland delineation also inspected a fringe of the Wetland #1 wetlands adja cent to the pond to the northwest, identifying that the pond is actually hydrologically c onnected to the southwest finger by a jurisdictional depression/channel (62, p. 9

, 24 ).

Wetland #2 and much of Source 1 are located in a 100- year flood plain (Ref. 33; Ref. 34; Ref. 12).

The hazardous substances migration pathway includes both the overl and and in

- water segments of the pathway along which hazardous substances would migrate from the source (Ref. 1, Section 4.1.1.1). Surface water runoff from Source 1 can flow either east, west, or south to Wetland #2, or north to

Wetland #1 (Ref. 14 , pp. 96, 99 ). The watershed at the Sauer Dump site includes sensitive environments (wetlands) and a human food chain fishery. While the 2012 wetland delineation has identified that Wetland #1 is hydrologically connected to Wetland #2, Wetland #1 is not evaluated for HRS scoring purposes as part of this HRS documentation record because it would not affect the site score.

The probable point of entry (PPE) of the hazardous substances from Source 1 into surface waters is Wetland #2, adjacent to the eastern, sou thern, and western boundaries of Source 1 (Ref. 62, p. 17 ; Ref. 33; Ref. 34). Surface water runoff from Source 1 follows the contours of the land and flows to Wetland #2. Maps showing the land contours are provided in Reference 14, pages 96 to 99, and 102 to 106 and Reference 15. Wetlands that are contiguous to a river (such as Wetland #2) are considered to be surface

water (Ref. 1, Section 4.0.2). Runoff from Source 1 can enter Wetland #2 at any location. Because Wetland #2 surrounds the eastern, southern, and western boundaries of Source 1, the PPE is the entire boundary of Wetland #2 adjacent to Source 1 (Ref. 14, pp. 96 to 99, and 102 to 106 ; Ref. 34 )

.

The target distance limit (TDL) defines the maximum distance over which targets are evaluated. The 15

- mile TDL starts at the PPE of hazardous substances to surface water and includes areas 15 miles

downstream from the most downstream PPE to surface water

, and the distance between the most upstream and downstream PPE (Ref. 1, Section 4.1.1.2). The in

- water segment of the surface water pathway TDL starts at the most upstream PPE from Source 1 to Wetland #2. As stated earlier, surface water runoff from Source 1 can enter Wetland #2 anywhere along the boundary of Source 1 and the wetland; Source 1 and the Wetland #2 are located adjacent to each other. There are two upstream PPEs into Wetland #2: one into the Southwest Finger of Wetland #2, labeled as PPE-1 in Reference 34 , and one into the Southeast Finger of Wetland #2, labeled as PPE- 2 in Reference 34 . The distance from PPE -1 and

PPE -2 to the Back River is approximately 630 feet and 320 feet, respectively

. From Wetland #2, the

Back River flows about 4.0 miles to the southeast and empties into the Chesapeake Bay. The remaining portion of the 15- mil e surface water migration pathway (11 miles ) is in the Chesapeake Bay (Ref. 13). The end of Back River is defined by the end the Tidal Back River watershed as shown in Reference 9, page 12, and is shown as line drawn between two land masses on Reference 1 3.

The Back River and Chesapeake Bay are tidally influenced within the TDL (Ref. 9, pp. 12, 32, 302, 324 ). When defining the TDL of a water body, tides are considered (Ref. 1, Section 4.1.1.2). Data do not exist to document the potential tidal carry of hazardous substances in the Back River; therefore, only targets identified within the downstream portion of the TDL have been scored. A report estimated the Back

### SWOF - Surface Water Overland Flow/Flood Migration Pathway

43 River tidal flow to be more than 4 miles upstream from Sauer Dump (Ref. 5, p. 15). Fisheri es and sensitive environments located outside the area of actual contamination (Wetland #2) will not significantly increase the site score because these targets are not subject to actual contamination , and any potential target values would be lowered by the high dilution weight value for the Back River (Ref. 1,

Table 4 -13, Section 4.1.3.3.2.3, and Section 4.1.4.3.1.3). Water level monitoring of the Back River at Sauer Dump in May and June 2002 recorded a mixed tide with a maximum daily tide of approximatel y 1.9 feet. The maximum recorded tidal fluctuation from the highest high tide to the lowest low tide was approximately 2.6 feet during the monitoring period (Ref. 14, p. 4).

Table 13 presents the TDLs for the Sauer Dump property.

TABLE 13

15- MILE T ARGET DISTANCE LIMIT

Surface Water Body Distance Measured PPE

- 1 and PPE

- 2 Reference

Wetland #2 630 feet (PPE

- 1) and 320 feet (PPE

- 2) 13

Back River 350 feet to 4 mile 13 Chesapeake Bay 4 to 15 miles 13

### SW - Observed Release

44 4.1.2.1 Likelihood of Release

4.1.2.1.1 Observ ed Release

Chemical Analysis
- 2007 Sediment Sampling

Between January 9 and 11, 2007, environmental consultants to MDE collected nine sediment samples from wetlands surrounding Source 1 and the Back River . The sediment samples were analyzed for lead by EPA Method 6010B and PCBs by EPA Method 8082 and 1668a in accordance with the EPA -approved

RAP and addendums. Samples were collected within the top 6 inches of sediment in accordance with

SOP 6 in the FSP

. The locations of the sediment samples are shown on Figure 8, page 80, of Reference 31 (Ref. 24 , p. 56 ; Ref. 25 , Appendix E, p. 27; Ref. 31, pp. 15 to 16 ). Reference 8 provides background and release sediment sampling locations as well as the lead and PCB concentrations detected in the samples.

Sedime nt samples were collected from beneath organic build -up or detritus material. Any decomposed organic material present at the sampling locations at time of sampling was included in the sample to accurately represent the potential for this interval to be im pacted by deposition and adsorption. Sediment samples were collected with a decontaminated stainless

- steel

, Wildco 2- inch liner

- type , hand- corer sediment sampler. Samples were placed in aluminum trays and homogenized using the coning and quartering method. A flat -bottom boat was used to collect o ff

- shore sediment samples (sample DG

SD01 -0.5). Sample DG- SD06

- 0.5 was collected with a disposable plastic trowel because the Wildco sampler was unable to retrieve a solid sediment sample ( Ref. 31 , p. 1 6 ).

Sedi ment samples were analyzed for PCBs using EPA Method 8082 and 1668B, and for lead using EPA Method 6010B (Ref. 31 , p. 105). Sample results were subject to data review, which include d an evaluation of the following: sample receipt temperatures, holding times, method blanks, laboratory control samples, matrix spike/matrix spike duplications, field duplicates, surrogates, instrument performance criteria, and calibration criteria. PCB homolog data, chromatograms, and raw data were also reviewed qualitatively (Ref. 31, pp. 21, 106). The data validation report is provided in Reference 31, Appendix B, page 104.

The analytical data from the sediment samples was reviewed in accordance with the procedures specified

in (1) the site

- specific Quality Assurance Proj ect Plan (QAPP) prepared by the environmental consultant, (2) EPA Functional Guideline documents for Organic and Inorganic Data Review, (3) EPA Region 3 Modifications to National Functional Guidelines for Organic Data Review, and (4) quality assurance and control parameters set by the project laboratories ( Ref. 31 , p. 105).

Background and release sediment sampling locations are shown in Reference 8. Table 14 summarizes the background sampling location and Table 15 presents PCB and lead concentrations dete cted in the background sample. Table 16 summarizes the release sampling locations and Table 17 presents PCB and lead concentrations detected in the release samples. As described in the paragraphs above, the sediment release and background samples are similar because the samples (1) were collected using the same procedures; (2) were collected within the same timeframe and, therefore, the same weather conditions (Tables 14 and 16 of this HRS documentation record); (3) were collected at locations with simila r topography and land use (Ref. 8); (4) were analyzed using the same methods (Ref. 31, pp. 15, 16); and (5) were collected from similar surface water bodies (wetlands) (Ref. 8). The 2002 wetland delineation describes Wetland #2 sediments as silt with cobbles with organics, and Wetland #1 sediments as silt/clay and clay loam and organics with silt with a few cobbles (Ref. 14, pp. 152, 156, 158, 160, 162). Both

### SW - Observed Release

45 wetland soil types are expected to contain a large amount of organic matter. The 1992 wetland delineation describes the soil in Wetland #2 (identified as Wetlands 3 through 6 in 1992) as Tidal Marsh to Mattapex silt loam and mucky, made land and mucky, and Tidal Marsh very black and mucky (Ref. 5, pp. 82 to 84) and Wetland #1 (identified as Wetlands 1 and 2 in 1992) as Mattapex silt loam and Tidal Marsh/Mattapex silt loam (Ref. 5, p. 80 to 81).

The 2007 sediment data from the Back River do not document a release to the Back River or actual

contamination in the Back River.

### SW - Observed Release

46 2007 Background:

TABL E 14

2007 BACKGROUND WETLAND SEDIMENT SAMPLES
- LOCATIONS

Sample

I dentification Sampling Location Depth (feet) Date Reference

DG

- SD01 -0.5 Pond wetland area (Wetland #1) that

borders the Source 1 to the

northwest 0.5 01/09/2007 Ref. 31, pp. 69, 80

Notes:

SD Sediment

TABLE 15

2007 BACKGROUND SEDIMENT CONCENTRATIONS

Sample

Identification Hazardous

Substance Concentration (mg/kg) SQL (mg/kg) (Ref. 52, pp. 2, 4) Reference

DG

- SD01 -0.5 Aroclor 1254 ND 0.048 Ref. 37 , p p

. 14, 15, 23

DG

- SD01 -0.5 Aroclor 1260 ND 0.048 Ref. 37 , p p

. 14, 15, 23

DG

- SD01 -0.5 Lead 7.5 0.23 Ref. 37, p p

. 14, 15, 34

Notes: All concentrations have been converted to mg/kg.

MDL Method detection limit mg/kg Milligram per kilogram

ND Not detected

SD Sediment SQL Sample quantitation limit

### SW - Observed Release

47 2007 Sediment Release Locations:

TABLE 16

2007 SEDIMENT SAMPLE RELEASE LOCATIONS (Wetland #2)

Sample ID Sampling Location Depth (feet) Date Reference

DG

- SD03 -0.5 Wetland that borders Source

1 to the west, southwest finger 0.5 01/10/2007 31, pp. 69, 80

DG

- SD04 -0.5 Wetland that borders Source

1 to the east , southeast finger 0.5 01/10/2007 31, pp. 69, 80

DG

- SD05 -0.5 Wetland that borders Source

1 to the east , southeast finger 0.5 01/10/2007 31, pp. 69, 80

DG

- SD06 -0.5 Wetland that borders Source

1 to the southeast , southeast finger 0.5 01/10/2007 31, pp. 69, 80

DG

- SD07 -0.5 Wetland that borders Source

1 to the southeast , southeast finger 0.5 01/11/2007 31, pp. 69, 80

Notes:

SD Sediment

### SW - Observed Release

48 TABLE 17

2007 RELEASE WETLAND #2 SEDIMENT SAMPLES

PCB AND LEAD CONCENTRATIONS

Sample

Identification Hazardous

Substance Concentration (mg/kg) Q SQL (mg/kg) (Ref. 52, pp. 2, 4) Date Reference

DG

- SD03

- 0.5 Lead 370 0.38 1/ 10 /2007 37 , p p

. 15, 33

DG

- SD03 -0.5 PCBs (Aroclor 1254) 0.91 0.079 1/10/2007 37, pp. 15, 25

DG

- SD03 -0.5 PCBs (Aroclor 1260) 1.4 0.079 1/10/2007 37, pp. 15, 25

DG

- SD04 -0.5 PCBs (Aroclor 1254) 3.3 0.39 1/10/2007 40, pp. 15, 31

DG

- SD05 -0.5 PCBs (Aroclor 1254) 0.580 0.092 1/10/2007 40, pp . 15, 30

DG

- SD05 -0.5 PCBs (Aroclor 1260) 0.510 0.092 1/10/2007 40, pp. 15, 30

DG

- SD06

- 0.5 Lead 595 0.49 1/10/2007 40 , p p

. 15, 46

DG

- SD06 -0.5 PCBs (Aroclor 1254) 15 L 1 1/10/2007 40, pp. 15, 32

DG

- SD07

- 0.5 Lead 150 0.36 1/11/2007 40 , p p

. 16, 48

DG

- SD07 -0.5 PCBs (Aroclor 1254) 1.1 0.075 1/11/2007 40, pp. 16, 34

N otes: All concentrations have been converted to mg/kg.

L A nalyte is present; reported value may be biased low; actual value is expected to be higher (Ref. 31, pp. 21, 22 , 69, 123) mg/kg Milligram per kilogram

PCB Polychlorinated biphenyl Q Data qualifie r SD Sediment SQL Sample quantitation limit

### SW - Observed Release

49 OTHER EVIDENCE OF RELEASES TO WETLAND (BACK RIVER)

1992 Sediment Sampling

Between December 7 and 9, 1992 , EPA contractors collected 17 sediment and 16 aqueous samples from wetland areas located adjacent to So urce 1 and from the Back River ( Ref. 5 , pp. 17, 86). Figure 2, page 22, of Reference 5, shows the sediment sampl ing locations. The background sediment sampling locations for the 1992 sampling event were SD-29 for the Back River and SD-26 for wetlands (Ref. 5, pp. 19 through 22 , 78 ; Ref. 53).

Table 18 summarizes the background sampling locations and Table 19 presents PCB and lead concentrations detected in the background samples. Background sampling locations are provided in Reference 5, page 22 . Tabl e 20 summarizes release sampling locations and Table 21 presents PCB and lead concentrations detected in the release samples. The locations of the 1992 sediment samples are

shown in Reference 53.

TABLE 18

1992 BACKGROUND SEDIMENT SAMPLING LOCATIONS

Sa mple

I dentification Sampling Location Depth Date Reference

SD -26 Northeastern tip of Wetland #2 Surface 12/08/1992 5, pp. 19, 22 , 78 ; 16., p. 35

SD -29 100 feet west of west tributary on

Back River Surface 12/09/1992 5 , p p . 19 , 22 , 78 ; 16, p. 40

Notes:

SD Sediment

TABLE 19

1992 BACKGROUND SEDIMENT CONCENTRATIONS

Sample

Identification Hazardous

Substance Concentration (mg/kg) Q Detection

Limit* (mg/kg) Date Reference

Wetland Background

SD -26 (MCGX05) Lead 68.3 0.6 12/8/1992 

### 5, pp. 22, 27, 323; 16, p. 35

SD -26 (CHH05) PCBs 0.1 U 0.033 12/8/1992 5, pp. 22, 59

, 509; 

### 16, p. 35
Back River Background

SD

- 29 (MCGX31) Lead 16.5 0.6 12/8/1992 5, pp. 22, 28, 335; 16, p. 40

SD

- 29 (CHH33) PCBs 0.047 U 0.033 12/8/1992 5, pp. 22, 60, 523; 16, p. 40

### SW - Observed Release

50 Notes from Table 19 : All concentrations have been converted to mg/kg.

* The detection limits are CRQLs and CRDLs (Ref. 30). mg/kg Milligram per kilogram

CRDL Contract -r equired d etection l imit CRQL Contract

- required quantitiation limit

PCB Polychlorinated b iphenyl Q Data qualifier

SD Sediment

U Not detected. The associated number indicates approximate sample concentration necessary to be detected (Ref. 5, p. 26).

TABLE 20

1992 RELEASE SEDIMENT SAMPLING LOCATIONS

Sample

I dentification Sampling Location Depth Date Reference

SD -1 Wetland #2 that borders property to

east Surface 12/08/1992 5 , p p . 19

, 22 ; 53 ; 16, pp. 24, 36

SD -2 Wetland #2 that borders property to

east Surface 12/08/1992 5 , p p . 20

, 22 ; 53 ; 16, pp. 20, 24, 38

SD -4 Small feeder tributary within Wetland #2 leading to cove, southeast corner of property Surface 12/08/1992 5, pp. 20, 22 ; 53 ; 16, pp. 20, 25, 38

SD -15 Wetland #2 that borders property to

west Surface 12/08/1992 5 , p p . 19

, 22 ; 53 ; 16, pp. 28, 36

SD -21 Wetland #2 that borders property to

west Surface 12/08/1992 5 , p p . 21

, 22 ; 53 ; 16, pp. 12, 21, 33,

39

SD -22 Wetland #2 that borders property to

west Surface 12/08/1992 5 , p p . 21

, 22 ; 53 ; 16, pp. 12, 21, 33,

39

SD -24 Wetland #2 that borders property to

west Surface 12/08/1992 5 , p p . 19

, 22 ; 53 ; 16, pp. 34, 37

SD -25 Wetland #2 that borders the property to the north Surface 12/08/1992 5 , p p . 20

, 22 ; 53 ; 16, pp. 35, 38, 39

SD -27 Wetland #2, borders property to the

east Surface 12/08/1992 5, pp. 19 , 22; 53 ; 16, pp. 11, 35, 38

Notes:

SD Sediment

### SW - Observed Release

51 TABLE 21

1992 RELEASE SEDIMENT CONCENTRATIONS

Sample

Identification Hazardous

Substance Concentration (mg/kg) Q Detection

Limit* (mg/kg) Reference

SD

- 1 (MCGX03) Lead 716 0.6 5, pp. 27, 322

SD

- 1 (CHH03) PCBs (Aroclor 1254) 11 0.033 5, pp. 59, 508

SD

- 2 (MCGX12) Lead 436 0.6 5, pp. 27, 326

SD

- 2 (CHH13) PCB (Aroclor 1254) 15 0.033 5, pp. 59, 513

SD

- 4 (CHH15) PCB (Aroclor 1254) 0.28 0.033 5, pp. 59, 515

SD

- 15 (MCGX07) Lead 288 0.6 5, pp. 27, 324

SD

- 21 (CHH23) PCBs (Aroclor 125 4 ) 0.22 0.033 5, pp. 60, 519

SD

- 22 (MCGX24) Lead 394 0.6 5, pp. 28, 332

SD

- 22 (CHH25) PCBs (Aroclor 1260) 4.8 (0.48) J 0.033 5, pp. 60, 520

SD

- 22 (CHH25) PCBs (Aroclor 1254) 3.1 (0.31) J 5, pp. 60, 520

SD

- 24 (MCGX09) Lead 839 0.6 5, pp. 27, 325

SD

- 24 (CHH09) PCBs (Aroclor 1260) 5.6 0.033 5, pp. 59, 511

SD

- 25 (MCGX 26) Lead 364 0.6 5, pp. 28, 33 3

SD

- 25 (CHH27) PCBs (Aroclor 1254) 0.14 0.033 5, pp. 60, 521

SD

- 27 (MCGX 28 ) Lead 1,060 0.6 5, pp. 28, 334

Notes:

All concentrations have been converted to mg/kg.

* The detection limits area CRQLs and CRDLs (Ref. 30). mg/kg Milligram per kilogram

CRDL Contract -r equired d etection l imit CRQL Contract -r equired q uantitation l imit

J Indicates that the analyte was present, but the reported value may not be accurate or precise (Ref. 5, p. 26 ).

The direction of bias of these J

- qualified results is not known. Therefore, the J

- qualified release value has been divided by PCB factor (10), making th is data eligible for Hazard Ranking System evaluation (Ref. 22, pp. 2, 8, 16). The concentration in the parentheses is the adjusted concentration.

PCBs Polychlorinated biphenyls Q Laboratory data qualifier

### SW - Observed Release

52 1999 Sediment Sampling

In 1999, MDE conducted a site assessment of the Sauer Dump property. As part of the assessment, MDE

collected sediment and surface water samples on September 29 and October 1, 1999. The sediment samples were analyzed for SVOCs, PCBs, and pesticides (Ref. 29, p. 3). The sampling locations are shown in Reference 29, pages 8 through 10. PCB and lead concentrations detected in the sediment samples are summarized in Table 22.

TABLE 22

1999 SEDIMENT PCB AND LEAD CONCENTRATIONS

Sample

Identification Hazardous

Substance Concentration (mg/kg) Date Reference

SED

- 1 Lead 186 9/2 9 /1999 2 9 , p p . 12 , 27

SED -1 PCBs (Aroclor 1254) 7.9 9/29/1999 29, pp. 15 , 27

SED

- 2 Lead 26.5 9/29/1999 29 , p p . 12 , 27

SED -2 PCBs (Aroclor 1254) 14.4 9/29/1999 29, pp. 15 , 27

SED

- 3 Lead 44.8 10/1/1999 29 , p p . 12 , 29

SED

- 4 Lead 32.4 10/1/1999 29 , p p . 12 , 29

SED -4 PCBs (Aroclor 1254) 2.1 10/1/1999 29, pp. 12 , 29

SED

- 5 Lead 33.8 10/1/1999 29 , p p . 12 , 29

SED

- 6 Lead 42.7 10/1/1999 29 , p p . 12 , 29

SED

- 7 Lead 109 9/29/1999 29 , p p . 12 , 26

SED -7 PCBs (Aroclor 1254) 2.0 9/29/1999 29, pp. 15 , 26

SED

- 8b (background sample) Lead 56.4 10/1/1999 29, pp. 12 , 29

SED

- 8b (background sample) PCBs (Aroclor 1254) ND 10/1/1999 29, pp. 12 , 29

SED

- 9 (dup of SED

- 2) Lead 182 9/29/1999 29, pp. 12 , 27

SED

- 9 (dup of SED

- 2) PCBs (Aroclor 1254) 2.0 9/29/1999 29, p p . 12, 15

, 27

S ED -10 PCBs (Aroclor 1254) 0.401 12/15/1999 29 , p p . 15 , 30,

31

Notes: All concentrations have been converted to mg/kg. mg/kg Milligram per kilogram

PCB Polychlorinated biphenyl

SED Sediment

ND None detected (Ref. 29, p. 15).

### SW - Attribution

53 Attribution:

As documented in the sections below, lead and PCBs detected in Wetland #2 are attributable to Source 1 because (1) Source 1 contains the same hazardous substances as Wetland #2, (2) Source 1 is not contained, (3) surface water runoff from Source 1 flows to Wetland #2, and (4) no other sources of lead

and PCB drain to the wetland.

Samples collected from the surface of Source 1 contained lead and PCBs. Runoff from Source 1 flows directly to Wetland #2 to which an observed release has been documented (Ref. 14, p. 16 and 99; Ref. 5, p. 4-5; Ref. 33; Ref. 34; Section s 2.4.1. and Section 4.1.1.1 and Tables 6, 7, 9, and 17 of this documentation record). Wetland #2 surrounds Source 1 along the eastern, southern, and western boundaries (Ref. 33). Other sources of contamination draining to Wetland #2 have not been identified. Other than Source 1, r esidential properties and u ndeveloped land drain to Wetland #2 (Ref. 25 , p. 10 ; Ref. 14, p. 10; Figure 2 of this documentation record ). As Reference 33 shows, Wetland #2 is fai rly isolated

from contamination from sources other than Source 1.

Wetland #2 serves as a sink for solids in runoff from Source 1. Because of the high organic content of the wetland, the wetland retards the transport of sediment, PCB, and lead. The tid e has a limited range, two feet, further limiting the transport from the wetland (Ref. 31, p. 39).

2001 Sediment Samples from Back River

Nine s ediment samples were collected from the Back River adjacent to Wetland #2 on December 18 and 19, 2001 by MDE contractors . The sediment sampling locations within the Back River were arranged in a grid pattern to determine the distribution of contaminants parallel and perpendicular to the shoreline of

the Back River. MDE used a sediment depositional pattern based on a 1974 aerial photograph and analytical results from previous sampling to determine the sediment sampling locations for the December 2001 sampling event (Ref. 14, p. 15 and Figure 3, p. 97). The sampling locations are shown on Figure 3, page 97, of Reference 14. A description of the sampling event is described in the paragraphs below. The sediment samples collected from Back River indicate that the river is not contaminated with lead and PCB adjacent to Wetland #2 based on the low concentrations of l ead and absence of PCB in the Back River sediments (Ref. 14, pp. 55, 56, 57, 58, 97).

In December 2001, sampling personnel collected s ediment samples from the Back River during times of higher tide by wading to each location. A shallow sediment sampl e and a deep sediment sample were collected from each sampling location . A 20 -inch long, 2-inch- diameter sediment sampler with a L exan liner, nosepiece

, and core catcher was used to collect each sample. The depth to the base of the loose sediment was determined at each sampling location. When the depth interval was less than 30 inches, the depth interval was divided in half and samples were obtained from each half of the depth interval. When the depth interval exceeded 30 inches, a shallow sample was collected from the top 20 inches and a deeper sample was collected from the bottom 10 inches. The depth to the base of the loose sediment ranged from 7 inches to over 30 inches. Debris, such as concrete, blocks, logs, and tires, were observed

in the sedime nt (Ref. 14, p. 15).

The sediment samples were submitted for laboratory analysis to Phase Separation Science, Inc. , in Baltimore, Maryland. The samples were analyzed for SVOCs using EPA Method 8070, total metals using EPA Method 200 series and Method 335.3, and pesticides and PCBs using EPA Method 8081/8082. Duplicate samples were collected from SDMT-6 (0-4 inches) and SDMT-4 (20-30 inches). All sampling was conducted in accordance with QA/QC guidelines ( Ref. 14 , p. 15).

### SW - Attribution

54 A review of the 2001 Back Riv er sediment sampling analytical results shows that lead and PCBs were detected at concentrations significantly lower than concentrations of lead and PCBs detected in Wetland #2. The lead and PCB concentrations were not significantly above the 2007 sediment background concentrations presented i n Table 1 5 of this documentation record. Lead concentrations ranged from 8.4 to 68 mg/kg. PCBs were not detected in the Back River sediment samples. Because the 2001 sediment samples were collected from the Back River immediately adjacent to Wetland #2, the analytical results provide evidence that the presence of lead and PCBs surrounding Source 1 (in Wetland #2) resulted from

a release from Source 1 and not from another source within the Back River or from the Back River (Ref. 14, pp. 55, 56, 57, 58, 97, 112). The concentrations of lead and PCB detected in the Back River sediments are illustrated in Figure 15, page 87 of Reference 31.

Lead and PCB Concentration Trends

Additional evidence that the PCB contamination in Wetland #2 is from Source 1 is that the PCB

concentrations in wetland sediment samples ( DG

- SD04, DG -SD05, and DG- SD06 ) collected directly downgradient of the hot spot area identified in Source 1 show decreasing levels of total PCB s the further the sediment sample is from the hot spot. The hot spot area is an area adjacent to Southeast Finger wetland where numerous source samples contained PCBs at concentrations exceeding 100 mg/kg. The

wetland PCB sediment concentrations are detected at a maximum o f 38.7 mg/kg. These results are consistent with historic levels of PCBs in sediment samples collected from the area , which have been reported as high as 267 mg/kg. Sample DG -SD07, which was collected from a location further downgradient of the hot spot a rea, shows a much lower concentration of total PCBs at 1.1 mg/kg. T otal

PCBs we re detected at even lower concentrations (0.067 mg/kg) near the mouth of the Southeast Finger (Wetland #2) in the Back River (see Figure 15, page 87, Reference 31) (Ref. 31, p p. 11, 25, 32, 40, 83).

Further, PCB concentrations in sediment samples from Wetland #2 and the Back River show a decreasing trend from the wetland (north) towards the Back River (south); this data are consistent with historic

sediment data from the Bac k River that have shown non

- detect concentrations of PCB. This decreasing trend is shown on Figure 15, page 87, of Reference 31. The lead concentrations in Wetland #2 and the Back River follow the same trend (Ref. 31, pp. 34, 87).

The trend in PCB and lead concentrations is further illustrated in the sediment samples collected from

both the tidal and non -tidal wetlands. Figure 4, page 99, of Reference 14 identifies the location of the wetlands. Figure 4 shows a 25-foot buffer zone surroundings the non- tidal wetland areas and the high water marks associated with the tidal wetlands associated with the Back River, south of Source 1. Figure 4 identifies Wetland #2 is a 1.39 acres divided into three areas: the Southwest Finger (non- tidal wetland),

the Bac k River Shoreline Area (tidal wetland), and the Southeast Finger (non-tidal wetland). Wetland #2 is comprised of a tidal wetland area along the shoreline (below the high water mark) and non

- tidal wetland areas in the Southwest Finger and the Southeast Fin ger (above the high water mark) ( Ref. 14, p. 16 and Appendix E, p. 150 ). As shown in Reference 8, sediment samples collected from the Southwest and Southeast Fingers of the non- tidal wetland contain observed release concentrations of PCB and lead providing evidence that the PCB and lead contamination in both the tidal and non-tidal portions of the wetland are at least partially attributable to Source 1

.

Lead and PCB in Back River Surface Water Samples

Two surface water samples were collected from Back River in 2007 during the extent of contamination

### SW - Attribution

55 study. The surface water samples were collected soon after the peak of high tide. One filtered and one unfiltered surface water sample from each of the two locations were analyzed for lead and PCBs (Ref. 31, pp. 18, 19). No PCBs were found in the surface water samples. Low concentrations of lead, ranging from non-detect to 0.0302 mg/L, were detected in the surface water samples (Ref. 31, p. 70). This provides evidence that the source of lead and PCB is unlikely to be tidal water that floods portions of

Wetland #2.

Hazardous Substances Released:

PCBs (Aroclors 1242, 1248, 1254, 1260)

Lead

Surface Water Observed Release Factor Value: 550

### SW/Human Food Chain Threat

– Toxicity/Persistence/Bioaccumulation

56 4.1.3.2 WASTE CHARACTERISTICS

4.1.3.2.1 Toxicity/ Persistence/Bioaccumulation

The combined toxicity, persistence, and bioaccumulation factor value is summarized in Table 23.

TABLE 23 TOXICITY, PERSISTENCE, AND BIOACCUMULATION FACTOR VALUES

Hazardous

Substances Source

No. Toxicity

Factor

Value Persistence

Factor

Value Bioaccumulation

Value* Toxicity/

Persistence/

Bioaccumulation

Factor Value

(Ref. 1, 4- 16 ) Ref. 2

Arcoclor

- 1242 (polychlorinated biphenyl) 1 10,000 1 50,000 5x10 8 Page

15

Aroclor 12 48 (polychlorinated biphenyl) 1 10,000 1 50,000 5×10 8 Page

15

Aroclor 1254 (polychlorinated biphenyl) 1 10,000 1 50,000 5×10 8 Page

15

Aroclor 1260 (polychlorinated biphenyl) 1 10,000 1 50,000 5×10 8 Page

15

L ead 1 10,000 1 5,000 5×10 7 Page

13

* Back River is brackish ; therefore , the higher of the freshwa ter or saltwater bioaccumulation value is assigned (Ref. 1, Section 4.1.3.2.1.3; Ref. 9, p. 32)

.

The highest combined toxicity, persistence, and bioaccumulation factor value is for PCB, 5×10 8

.

Toxicity/Persistence/Bioaccumulation Factor Value: 5×10 8
[Ref. 1 , T able 4 -16]

### SW/Human Food Chain Threat

– Waste Characteristics

57 4.1.3.2.2 Hazardous Waste Quantity

Source Number Source Hazardous Waste Quantity Value (Section 2.4.2.1.5) Is source hazardous constituent quantity data complete? (yes/no)

1 31.77 No

Hazardous Waste Quantity Assigned Value: 10 0* [Ref. 1 , Section 2.4.2.2]

* Because the hazardous constituent quantity is not adequately determined and because targets in this pathway are subject to actual contamination, a hazardous waste quantity factor value of 100 is assigned (Ref. 1, Section 2.4.2.2; Section 4.1.4.3 of this documentation record).SW/Human Food Chain

– Waste Characteristics



### 58 4.1.3.2.3 Waste Characteristics Factor Category Value

The waste characteristics factor value for the human food chain threat is calculated below, as specified in the HRS Final Rule (Ref. 1, Sectio n 4.1.3.2.3):

Toxicity/Persistence Factor Value = 10,000 HWQ Factor Value = 100 Bioaccumulation Potential Factor Value (BPFV) = 5x10 4

Toxicity/Persistence Factor Value (10,000) × HWQ Value (100) = 1×10 6

1×10 6 × BPFV (5x10 4 ) = Waste Characteristics Produ ct (5x10 10 ) (subject to maximum value of 1×10 10 )

Waste Characteristics Factor Category Value (Ref. 1, Table 2 -7) = 320

Waste Characteristics Factor Category Value: 320 [Ref. 1 , T able 2 -7]SW/Human Food Chain Threat

– Targets



### 59 4.1.3.3 HUMAN FOOD CHAIN THREAT
- TARGETS

Actual Human Food Chain Contamination

Actual contamination of a human food chain has not been documented.

Back River is a fishery adjacent to wetlands surrounding Source 1 (Ref. 9, pp. 32, 65, 66, 73, 77, 258, 274, 302, 304, and 324 ; Ref. 63 ). Back River is designated by Maryland Water Quality Standards for surface water (Code of Maryland Regulations [COMAR] 26.08.02.07) for the ti dal

waters as Use I

– water -contact recreation, fishing, and protection of aquatic life and wildlife (Ref. 9, p. 274). Back River is also designated as Use II area – support of estuarine and marine aquatic life and shellfish harvesting – subcategories 1, 2, and 3, according to Maryland W ater Q uality S tandards . As a subcategory 1 Migratory Fish Spawning and Nursery Migratory Area,

Back River is a habitat for fish including striped bass, perch, shad, herring , and Shortnose Sturgeon during the late winter/spring spawning and nursery season. Back River consists of tidal

freshwater and provides low

- salinity habitats. This habitat zone is primarily found in the upper reaches of many Chesapeake Bay tidal rivers and creeks and the upper mainstem Chesapeake Bay (Ref. 9, p. 65).

As a subcategory 2 Shallow Water –Submerged Aquatic Vegetation Underwater Area, bay

grasses a nd many fish and crab species depend on areas of Back River as a shallow

- water habitat.

Shallow waters consist of grass beds near the shoreline. As a subcategory 3 Open

- Water Fish and

Shellfish Water Area, Back River provides a surface water habitat for diverse populations of sportfish including striped bass, bluefish, mackerel, and seatrout ; bait fish such as menhaden and

silversides as well as the S hortnose Sturgeon. These species reside within tidal creeks, rivers, embayments, and the mainstem Chesapeake Bay year -round (Ref. 9, p. 65, 66, 324; Ref. 38; Ref. 39).

Analytical data from sediment samples collected from Wetland #2 document that an observed

release of hazardous substances has occurred from the Source 1 to this wetland, which is part of

the B ack River

.

The Chesapeake Bay is located within the 15

- mile TDL and is a major recreational and commercial fishery (Ref. 13; Ref. 44; Ref. 45; Ref. 46).

4.1.3.3.1 Food Chain Individual

As noted in Section 4.1.2.1.1 of this HRS documentation record, an observed release of hazardous substances having a bioaccumulation factor value of 500 or greater is documented in

wetlands of the Back River and a human food chain fishery is present within the TDL (Ref. 9, pp.
32, 65, 66, 73, 77, 258, 274, 302, 304, 324 ; Ref. 63). The food chain individual factor is assigned

a value of 20 (Ref. 1 , Section 4.1.3.3.1).

Food Chain Individual Factor Value: 20 (Ref. 1

, Section 4.1.3.3.1)

4.1.3.3.2 Population

No fisheries subject to Level I or Level II concentrations ha ve been documented because fishing has not been documented within the zone of contamination. Documentation regarding the

amount of fish and crabs harvested from surface water bodies within the TDL has not beenSW/Human Food Chain Threat

– Targets



### 60 identified. A Level I and II human food chain population value of 0 is assigned (Ref. 1, Section 4.1.3.3.2)

.

Level I and II Human Food Chain Population Value: 0

4.1.3.3.2.3 Potential Human Food Chain Contamination

Back River and Chesapeake Bay are both designated fisheries located within the 15

- mile downstream TDL (Ref. 9, pp. 32, 65, 66, 73, 77, 258, 274, 302, 304, 324; Ref. 63). Production values for the Back River and the portion of the Chesapeake Bay within the 15- mile surface water TDL are not known. A value of greater than 0 is used to obtain an assigned human food chain population value of 0.03 from Table 4-18 of Reference 1. No flow rate gauging stations are located on the Back River as the river is considered a tidal water body (Ref. 9, pp. 18, 32; Ref. 60). Therefore, to be conservative, the lowest dilution weighed value for a river in Table 4-13 of Reference 1 is assigned to Back River; the value is 0.00001. To obtain the potential human food chain value, the assigned human food chain value of 0.03 is multiplied by the dilution weig ht for a very large river (0.00001) (Ref. 1, Table 4-13) and divided by 10 giving a value of 0.00000003 (Ref. 1, Section 4.1.3.3.2.3). The same calculations apply to the Chesapeake Bay. Using the dilution weight for coastal tidal water (0.0001) and a human food chain value of 0.03 and dividing by 10, a value of 0.0000003 is obtained for the Chesapeake Bay (Ref. 43, p. 1). The sum of the two values is 0.00000033 (Ref. 4.1.3.3.2.3).

Potential Human Food Chain Contamination Factor Value = 0.00000033SWOF/Envir onmental Threat

– Toxicity/Persistence/Bioaccumulation



### 61 4.1.4 ENVIRONMENTAL THREAT

4.1.4.2 WASTE CHARACTERISTICS

4.1.4.2.1 Ecosystem Toxicity/Persistence/Bioaccumulation

Table 24 presents the ecosystem toxicity/persistence factor values for hazardous substances detected in

Source 1.

TABLE 24

ECOSYSTEM TOXIC ITY AND PERSISTENCE FACTOR VALUE

Hazardous

Substances Source

No. Ecosystem Toxicity

Factor

Value* Persistence

Factor

Value Ecosystem Toxicity/Persistence Factor Value (Ref. 1,

Table 4 -20) Reference

2

Polychlorinated biphenyl (Aroclors 1242, 1248, 1254,

12 6 0) 1 10,000 1 10,000 Page 15

Lead 1 1,000 1 1,000 Page 13

Notes:

* Back River is brackish; therefore, the higher of the freshwater or saltwater ecosystem toxicity values is assigned (Ref. 1, Section 4.1.3.2.1.3; Ref. 9, p. 32 ; Ref. 14, pp. 151, 152; Ref. 5, pp. 74 to 83)

.SWOF/Envir onmental Threat

– Toxicity/Persistence/Bioaccumulation



### 62 TABLE 25 ECOSYSTEM TOXICITY, PERSISTENCE, AND BIOACCUMULATION FACTOR VALUE

Hazardous

Substances Ecosystem Toxicity/Persistence

Factor Value Ecosystem

Bioaccumulation

Factor Value* (Section 4.1.3.2.1.3) Ecosystem Toxicity/

Persistence/

Bioaccumulation Factor Value (Ref. 1, Table 4-21 Reference

2

Polychlorinated biphenyl (Aroclors 1242, 1248, 1254, 1260) 10,000 50,000 5×10 8 Page 15

Lead 1,000 50,000 5×10 7 Page 13

Notes:

* Back River is brackish; therefore, the higher of the freshwater or saltwater ecosystem bioaccumulation factor values is assigned (Ref. 1, Section 4.1.3.2.1.3; Ref. 9, p. 32; Ref. 14, pp. 151, 152; Ref. 5, pp. 74 to

83 ).

The highest toxicity, persistence, and bioaccumulation factor value is for PCBs: 5×10 8

.

Ecosystem Toxicity/Persistence/Bioaccumulation Factor Value: 5×10 8
(Ref. 1, T able 4 -21)SWOF/Environmental Threat

– Hazardous Waste Quantity



### 63 4.1.4.2.2 Hazardous Waste Quantity

Source Number Source Hazardous Waste Quantity Value (Section 2.4.2.1.5) Is source hazardous constituent q uantity data complete? (yes/no)

1 31.77 No

HWQ Factor Value: 100* (Ref. 1, Section 2.4.2.2, p. 51591)

* Because the hazardous constituent quantity is not adequately determined and because targets in this pathway are subject to actual contamination

, a HWQ factor value of 100 is assigned (Reference 1, Section 2.4.2.2; Section 4.1.4.3 of th is documentation record).SWOF/Environmental Threat –Waste Characteristics



### 64 4.1.4.2.3 Waste Characteristics Factor Category Value

The waste characteristics factor category value is determined by taking the product of the highest ecosystem toxicity/persistence factor value (10,000) and the HWQ value (100), and multiplying the product by the highest ecosystem bioaccumulation factor value (50,000) (Ref. 1, Section 4.1.4.2.3).

10,000 × 100 = 1 × 10 6

E cosystem toxicity/persistence factor value × h azardous waste quantity factor value: 1 × 10 6

1 × 10 6 × 50,000 = 5 × 10 10

(E cosystem toxicity/persistence × hazardous waste quantity) × ecosystem bioaccumulation potential

factor value: 5 × 10 10 (subject to maximum value of 1×10 10 )

Waste Characteristics Factor Category Value: 320 (Ref. 1, Table 2 -7)SWOF/Environmental Threat –Targets



### 65 4.1.4.3 Environmental Threat- Targets

Level I Concentrations

No Level I concentrations of sensitive environments have been documented within the 15- mile

downstream TDL.

Most Distant Level II Sample

Actual environmental contamination has been documented in the wetlands of Back River, as discussed in

Section 4.1.1.1 of this HRS documentation record. As presented in Table 17 of this HRS documentation record, sediment samples collected from Wetland #2 contained lead and PCBs at concentrations documenting an observed release to the wetland (surface water). The wetland area subject to actual

contamination is shown in Reference 34. The area of these wetlands was delineated in 1 992. The 1992 wetland delineation used the National Wetlands Inventory mapping for preliminary identification of

wetland areas. The w etlands were numbered Wetland Unit s 1 through 6 (Ref. 5, p. 74, 78 ). The wetlands

within the area of actual contaminatio n include Wetland Unit 3, a palustrine, emergent persistent saturated soil wetland (PEM1B) located southeast of Wetland Unit 2 (Ref. 5, p. 82); Wetland Unit 4, an intertidal estuarine emergent persistent irregularly flooded wetland (E2EM1P) located southea st of Wetland Unit 3 and extending to the mudflats on the Back River (Ref. 5, p. 82); Wetland Unit 5, an intertidal estuarine emergent persistent regularly flooded wetland (E2EM1N); and Wetland Unit 6, an intertidal estuarine mud flat with regular flooding (E2FL3N) (Ref. 5, p. 83). The description of the wetlands identifies hydrophytic vegetation within Wetland Units 3, 4, and 5 and not within Unit 6 and hydric soils and the presence of wetland hydrology in each unit (Ref. 5, pp. 83, 84). However, a wetland delineation conducted in April 2002 identified phragmites and narrow-leaved cattail, both hydrophytes, as dominant species within Unit 6 (Ref. 14, pp. 151, 152; Ref. 5, pp. 83, 84 ).

The 2002 wetland delineation identified two wetlands, Wetland #1 and #2. Wetland #2 includes the 1992 Wetland Units 3 through 6. The 2002 wetland delineation identified hydric soils, wetland hydrology, and predominance of hydrophytic vegetation in Wetland #2, including the 1992 Wetland Unit 6 (Ref. 14, pp. 151, 152). Th e locations of the wetlands are shown in Reference 5, Figure 4 -1, page 78 and Reference 14, Figure 5, page 99 and page 167.

The 2012 wetland delineation was performed using the USACE 2010 Interim Regional Supplement to the Corps of Engineers Wetland Deli neation Manual; Atlantic and Gulf Coastal Plain Region (Version 2.0) and the delineated wetlands were determined to meet HRS requirements (Ref. 62, pp. 6, 11). The results of this 2012 delineation were generally consistent with and confirmed the results of the 2002 delineation, with slight adjustments to the boundaries of the wetlands (Ref. 14, p. 163; Ref. 34; Ref. 62, pp. 1, 8 to 10, 17). The 2012 wetland delineation also inspected a fringe of the Wetland #1 wetlands adjacent to the pond to the northwes t, identifying that the pond is actually hydrologically connected to the southwest finger by a jurisdictional depression/channel (62, p. 9, 24).SWOF/Environmental Threat –Targets



### 66 Th e sediment sampling locations documenting an observed release to surface water are listed below.

TABLE 2 6

LEVEL II RELEASE SAMPLES

Sample

I dentification Sample

Medium Sampling Location Reference

DG

- SD03 -0.5 Sediment Wetland that borders

Source 1 to the west 31, pp. 69, 80

DG

- SD04 -0.5 Sediment Wetland that borders

Source 1 to the east 31, pp. 69, 80

DG -S D05 -0.5 Sediment Wetland that borders

Source 1 to the east 31, pp. 69, 80

DG

- SD06 -0.5 Sediment Wetland that borders

Source 1 to the southeast 31, pp. 69, 80

DG

- SD07 -0.5 Sediment Wetland that borders

Source 1 to the southeast 31, pp. 69, 80

According to the Baltimore County Department of Permits and Development Management, Sauer Dump

is zoned as a Resource Conservation Critical Area (Ref. 26, pp. 1, 2; Ref. 41) under the Critical Area Act

. In 1984, the Maryland General Assembly resolved to reverse the d eterioration of the Chesapeake Bay’s environment by enacting the Chesapeake Bay Protection Act. In 2002, the Act was amended to include the Atlantic Coastal Bays. The Act required the 16 counties, Baltimore City, and 44 municipalities surrounding the Che sapeake and Atlantic Coastal Bays to implement a land use and resource management program designed to mitigate the damaging impact of water pollution and loss of natural habitat, while also accommodating the jurisdiction’s future growth. The Critical Area Act recognizes that the land immediately surrounding the Bays and their tributaries has the greatest potential to affect water quality and wildlife habitat and thus designated all lands within 1,000 feet of tidal waters or adjacent tidal

wetlands as the “Critical Area ” (Ref. 41, p.1; Ref. 54, pp. 17, 18).

The Critical Area Act falls within the Maryland Coastal Nonpoint Pollution Control Program. National Oceanic and Atmospheric Administration ( NOAA ) and EPA approved the Coastal Nonpoint Pollution Control Program submitted by the State of Maryland pursuant to Section 6217(a) of the Coastal Zone Act Reauthorization Amendments of 1990 (Ref. 54, p. 1 ; Ref. 56 ). The Maryland Coastal Nonpoint Pollution Control Program is part of Maryland Water Pollution Contro l Laws within the Maryland Coastal Management Program, which has been approved by NOAA under the Coastal Zone Management Act (Ref. 55, pp. 3, 6; Ref. 56, p. 1). Maryland’s Critical Area’s program is the principal mechanism used by Maryland’s Coastal Program to designate areas for preservation and restoration. Areas of special significance within the coastal zone are identified and designated State Critical Areas. Three types of coastal areas are designated. Sauer Dumps falls within the resource protecti on area (Ref. 55, p. 22; Ref. 26, pp. 1, 2). Resource protection areas consist of vegetated wetlands, upland natural areas, prime recreation areas, productive agricultural land, areas of historical and archeological importance, and aquatic resource areas (Ref. 55, p. 22).

Source 1 lies within the area designated as the Chesapeake Bay Critical Area under Maryland's Chesapeake Bay Critical Area Protection Act . T he purpose of Maryland's Chesapeake Bay Critical Area Protection Act is to protect the unique Chesapeake Bay ecosystem and its fisheries and other resources. Specifically, the portion of Source 1 located adjacent to Lynhurst Road is within a l imited developmentSWOF/Environmental Threat –Targets

Sensitive Sensitive Environment Sensitive Reference Environment Value (Ref. 1, Table s 4

- Environment Type 23 and 4-24) 26, pp. 1, 2; 32; 54, p. Area identified

Critical Area 1; 55, p. 22; 56 (see under Coastal Zone 100 paragraphs above) Management Act

Wetland #2 34 Wetland 25



### 67 a rea and the remainder o f Source 1 is within a resource conservation area (the most protective and restrictive classification) (Ref. 26; Ref. 32 ). The Chesapeake Bay Critical Area Protection Program established, preserves, and maintains a 100 -foot, naturally vegetated, forested buffer from the mean high

water line of tidal waters or from th e edge of tidal wetlands and tributary streams. This includes non- tidal

w etlan ds (Ref. 32). The high water line on the Sauer Dump property is shown on Figure 4, page 99, of

Reference 14.

The Chesapeake Bay and its tributaries provide habitat, including spawning habitat, feeding area, and migratory pathways, for several species of anadromous fi sh, including the depleted striped bass,

American hickory, gizzard shad, river herring (various species) , and yellow and white perch. Shallow

areas of streams are particularly important as spawning habitat. C ritical spawning or feeding areas or migratory pathways are not known to exist within the study areaof the Back River (Ref. 9, pp. 66, 114 ,)

.

Sensitive environments associated with the Back River include areas known to be used as a habitat for federally endangered species. The Back River, a tributary to the Chesapeake Bay, provides habitat to the Shortnose Sturgeon (Acipenser brevirostrum) . The Shortnose Sturgeon is a f ederally e ndangered species (Ref. 36, p. 2; Ref. 38; Ref. 39). Reference 38 shows the distribution of the Shortnose Sturgeon. Reference 39 provides a description of the habitat of the Shortnose Sturgeon.

Wetlands surround Source 1 (Ref. 15; Ref. 33; Ref. 34). When the PPE to surface water is into a wetland, the wetland perimeter is used to determine the length of the wetland subject to Level II concentrations (Ref. 1, Section 4.1.4.3.1.2). While the 2012 wetland delineation has identified that Wetland #1 is hydrologically connected to Wetland #2, Wetland #1 is not evaluated for HRS scoring purposes as part of

this HRS documentation record because it would not affect the site score. There are two PPEs from Source 1 into Wetland #2, the Level II wetland. PPE-1 is into the Southwest Fin ger of Wetland #2 at the north end, as shown in Reference 34. PPE-2 is into the Southeast Finger of Wetland #2 at the north end, as shown is Reference 34. To determine the perimeter of the Level II wetland in the Southwest and Southeast Fingers of Wetland #2, an arc is drawn from each PPE to the furthest downstream sediment sampling location documenting an observed release to the wetland. The arc drawn in the Southwest Finger is labeled Arc 1 on Reference 34. The arc is drawn from PPE- 1 to sediment samp ling location

DG

- SD03 -0.5. The arc drawn in the southeast finger is labeled Arc 2 on Reference 34. The Arc 2 is drawn from PPE-2 to sediment sampling location DG- SD07 -0.5. The perimeter of the Level II Southwest Finger is estimated to be 1,230 feet and the perimeter of the Level II Southeast Finger is

estimated to be 1,041 feet. The sum of the two Level II wetlands is 2,271 feet (Ref. 34). A wetland assigned value of 25 is obtained from Reference 1, Table 4- 24. Table 2 7 summarizes Level II sensitive

environments in Back River Wetland #2.

TABLE 2 7

LEVEL II SENSITIVE ENVIRONMENTS

– BACK RIVER WETLAND #2SWOF/Environmental Threat –Targets



### 68 The Level II concentration values are the sum of the sensitive environment values subject to Level II concentrations, or 125 (Ref. 1, Section 4.1.4.3.1.2).

Level II Concentrations Factor Value: 125