HRS DOCUMENTATION RECORD REVIEW COVER SHEET 

Name of Site: HORTON IRON & METAL CO. 

NCN 000 407 480 

Contact Persons:

U.S. Environmental Protection Agency, Region 4: 

Jennifer Wendel 

NPL Coordinator (404) 562-8799 

 

North Carolina Department of Environment and Natural Resources: 

Site Investigation: Melanie Bartlett (919) 508-8480 

 

Documentation Record: 

 Melanie Bartlett (919) 508-8480 

Pathways, Components, or Threats Not Evaluated:

Ground Water Migration Pathway 

The ground water migration pathway was not scored because scoring the ground 

water pathway would have a minimal impact on the site score. 

Surface Water Pathway 

Drinking Water threat/targets: 

The drinking water threat was not scored because there is no drinking water 

intake within the 15-mile surface water pathway downstream of the site. Thus, 

this threat would have minimal or no impact on the site score. 

 Environmental threat/targets: 

The environmental threat was not scored as the impact on the site score would be 

minimal. 

Soil Exposure Pathway 

The soil exposure pathway was not scored because there are no residents, schools 

or daycares onsite; the property is fenced and secured; and exposure to workers 

stationed on or within 200 feet of the contaminated areas on a routine basis is 

minimized. Due to this, the soil exposure pathway would have a minimal impact 

on the overall site score. 

Air Pathway 

The air pathway was not scored because scoring the pathway would have a 

minimal impact on the site score. 
1 

HRS DOCUMENTATION RECORD 

Name of Site: Horton Iron & Metal Co. 

EPA Region: 4 

Date Prepared: October 2010 

Street Address of Site*: 2216 US Highway 421 N 

County, State, and ZIP: Wilmington, New Hanover County, NC 28401 

General Location in the State: Southeast North Carolina 

Topographic Map: CASTLE HAYNE, NC 

Latitude: 34 o 15’ 59.94” 

Longitude: -77o 57’ 14.70” 

Location is within Source 1 just southwest of PPE2 

(Ref. 3, p. 1; Figs. 1, 3, 6) 

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

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

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

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

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

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

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

need to be addressed under CERCLA. Accordingly, EPA contemplates that the preliminary description of 

facility boundaries at the time of scoring will be refined as more information is developed as to where the 

contamination has come to be located. 

Scores

Ground Water Pathway Not Scored 

Surface Water Pathway 96.06

Soil Exposure Pathway Not Scored 

Air Pathway Not Scored 

HRS SITE SCORE 48.03
2 

WORKSHEET FOR SITE SCORE

S S2

1. Ground Water Migration Pathway Score Not Scored 

2a. Surface Water Overland/Flood Migration -- 

Drinking Water Threat Not Scored 

Food Chain Threat 96.06 

Environmental Threat Not Scored 

Surface Water Overland/Flood Migration Component 

(subject to maximum value of 100, Ref. 1, section 4.1.5) 96.06 9,227.5236 

 

3. Soil Exposure Pathway Score Not Scored 

4. Air Migration Pathway Score Not Scored 

5. Total of Sgw

2

 + Ssw2 + Ss

2

 + Sa

2

 = 9,227.5236 

6. HRS Site Score: Value on line 5. divided by four, 

then take the square root 48.03__ 

 
3 

HRS TABLE 4-1 -Surface Water Overland/Flood Migration Component Scoresheet 

Factor Categories and Factors Maximum 

Value 

Value 

Assigned 

Drinking Water Threat 

Likelihood of Release:

1. Observed 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 x [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) - 

7. Hazardous Waste Quantity (a) - 

8. Waste Characteristics 100 - 

Targets:

9. Nearest Intake 50 - 

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 - 

12. Targets (lines 9 + 10d + 11) (b) - 

Drinking Water Threat Score:

13. Drinking Water Threat Score ([lines 5 x 8 x 

12]/82,500, subject to a maximum of 100) 

100 - 

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 108 

16. Hazardous Waste Quantity (a) 100 

17. Waste Characteristics 1,000 320 
4 

Factor Categories and Factors Maximum 

Value 

Value 

Assigned 

Targets:

18. Food Chain Individual 50 45 

19. Population: 

 19a. Level I Concentrations (b) - 

 19b. Level II Concentrations (b) 0.03 

 19c. Potential Human Food Chain Contamination (b) - 

 19d. Population (lines 19a + 19b + 19c) (b) 0.03 

20. Targets (lines 18 + 19d) (b) 45.03 

Human Food Chain Threat Score:

21. Human Food Chain Threat Score ([lines 14 x 17 x 

20]/82,500, subject to a maximum of 100) 

100 96.06 

Environmental Threat 

Likelihood of Release: 

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

23. Ecosystem Toxicity/Persistence/Bioaccumulation (a) - 

24. Hazardous Waste Quantity (a) - 

25. Waste Characteristics 1,000 - 

Targets:

26. Sensitive Environments:

 26a. Level I Concentrations (b) - 

 26b. Level II Concentrations (b) - 

 26c. Potential Contamination (b) - 

 26d. Sensitive Environments (lines 26a + 26b + 26c) (b) - 

27. Targets (value from 26d) (b) - 

Environmental Threat Score:

28. Environmental Threat Score 

([lines 22 x 25 x 27]/82,500, subject to a maximum of 60) 

60 - 

Surface Water Overland/Flood Migration Component Score 

For A Watershed 

29. Watershed Scorec

(lines 13 + 21 + 28, subject to a maximum of 100) 

100 96.06 

Surface Water Overland/Flood Migration Component Score 

30. Component Score (Sof)

c

, (highest score from line 29 for all 

watersheds evaluated, subject to a maximum of 100) 

100 96.06 

a

Maximum value applies to waste characteristics category. 

b

Maximum value not applicable. 

c

Do not round to nearest integer. 
5 

HORTON IRON & METAL CO. 

WILMINGTON, NEW HANOVER COUNTY, NC 

LIST OF REFERENCES 

1. US Environmental Protection Agency (USEPA); Hazard Ranking System, Final Rule, 55 

FR 51532. Excerpt. Cover page only. A complete copy of the Hazard Ranking System 

document is available in the Region 4 Docket. 

2. USEPA; Superfund Chemical Data Matrix (SCDM). January 2004. Excerpt. 15 pages. 

A complete copy of SCDM is available at 

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

3. US Geological Survey, 7.5-minute topographic quadrangle maps of North Carolina: 

Castle Hayne, 1997; Wilmington, 1993; Leland, 1997; Winnabow, 1990; Funston, 1990; 

and Carolina Beach, 1997. 6 maps merged and modified into two. Scale 1:100,000. 2 

pages.

4. Bryson, Melanie and Bateson, Jim, NC Department of Environment and Natural 

Resources (NCDENR). Expanded Site Inspection, Horton Iron & Metal Co., NCN 000 

407 480, Wilmington, New Hanover County, NC. September 17, 2003. 284 pages. 

5. Oneida Total Integrated Enterprises. Expanded Site Inspection Report, Revision 2, 

Horton Iron & Metal, NCN 000 407 480, Wilmington, New Hanover County, NC. 

March 3, 2010. 851 pages. 

6. Reference reserved. 

7. Reference reserved. 

8. USEPA, Office of Solid Waste and Emergency Response, Using Qualified Data to 

Document an Observed Release and Observed Contamination. November 1996. 18 

pages. 

9. New Hanover County Tax Department, Property Assessment. Tax Records for 2216 US 

Highway 421 North, Wilmington, NC. December 14, 2009. 5 pages. Records are 

available at http://etax.nhcgov.com/Main/Home.aspx. 

10. North Carolina Department of the Secretary of State. Corporation Records for Horton 

Iron and Metal Company. March 18, 2010. 7 pages. Records are available at 

http://www.secretary.state.nc.us/corporations/. 

11. Carlton, Roger, USEPA, Region 4 Science and Ecosystem Support Division, Quality 

Assurance Project Plan for Horton Iron and Metal Co., Inc. July 29, 2009. 26 pages. 
6 

HORTON IRON & METAL CO. 

WILMINGTON, NEW HANOVER COUNTY, NC 

LIST OF REFERENCES 

12. Stanley, Jeanette, NC Superfund Section. Memo to File, RE: Ownership history. April 

29, 2002. 44 pages. 

13. Sanborn Maps of Wilmington, NC dated 1915 and 1951. 2 pages. 

14. Stanley, Jeanette, NC Superfund Section. Memo to Staff; RE: Fertilizer Manufacturing 

Facilities, Contaminants of Concern. January 29, 1999. 54 pages. 

15. Application by Horton Industries, Proposed Dredging on North East Cape Fear River 

Opposite Smiths Creek, May 5, 1961. 1 page. 

16. Bryson, Melanie, NC Superfund Section. Memo to File; RE: Telephone Call Summary, 

December 11, 2002. 1 page. 

17. Bryson, Melanie, NC Superfund Section. Memo to File, Subject: On-site Reconnaissance 

Field Notes, January 17, 2003. 3 pages. 

18. Clayton Environmental Consultants, Phase 1 Environmental Assessment at W.S. Clark 

and Sons, Inc. Location No. 107, 2400 Highway 421 North, Wilmington, North Carolina, 

July 23, 1992. 81 pages. 

19. Stanley, Jeanette and Bateson, Jim, NC Superfund Section, CERCLIS Site Addition 

Letter, April 29, 2002. 6 pages. 

20. Search Superfund Site Information/ Superfund/ US EPA, CERCLIS info for Horton Iron 

& Metal Co., Northeast Chemical Company Site, and V.C. Chemical - Almont Works 

from web found at http://cfpub.epa.gov/supercpad/cursites/csitinfo.cfm?id=0407480. 

Accessed March 22 and August 17, 2010. 4 pages. 

21. Bryson, Melanie, NCDENR Superfund Section, Abbreviated Preliminary Assessment 

Checklist, February 11, 2003. 2 pages. 

22. Bryson, Melanie, NC Superfund. Memo to File, Subject: On-site Reconnaissance Field 

Notes. March 12, 2003. 2 pages. 

23. Bryson, Melanie, NC Superfund. Memo to File, Subject: Well Installation Field Notes 

Horton Iron & Metal. April 10, 2003. 4 pages. 

24. Striggow, Brian, US EPA Region 4, SESD Memo to Ken Mallary, North Site 

Management Branch, Subject: Horton Iron Well Installation Report. March 26, 2003. 9 

pages. 
7 

HORTON IRON & METAL CO. 

WILMINGTON, NEW HANOVER COUNTY, NC 

LIST OF REFERENCES 

25. Bryson, Melanie, NC Superfund. Memo to File; Subject: ESI Sampling Trip Report. 

April 10, 2003. 27 pages. 

26. Harrigan, Sandra and Cotton, Ed, Tetra Tech START III to Kevin Misenheimer US EPA 

Region 4 On-Scene Coordinator Subject: Final Removal Assessment (RA) Letter Report. 

April 11, 2007. 86 pages. 

27. Bartlett, Melanie, NC Superfund. Memo to File; Subject: Phosphate fertilizer Industry 

Description and Practices. March 25, 2010. 4 pages. 

28. US EPA Office of Enforcement and Compliance Assurance, A Guide for Ship 

Scrappers: Tips for Regulatory Compliance. Summer 2000. 261 pages. 

29. Giese, G. L., H.B. Wilder, and G. G. Parker, Jr. Hydrology of Major Estuaries and 

Sounds of North Carolina, U.S. Geological Survey Water-Supply Paper 2221. Excerpt. 

38 pages. 

30. Stanley, Jeanette, NC Superfund Section. Memo to File, Subject: Flow Rates of the 

Northeast Cape Fear and Cape Fear Rivers. VC Chemical – Almont Works. February 

17, 2000. 6 pages. 

31. USEPA Region 4. Northeast Chemical Company Site Fact Sheet. 

http://wastenot.enr.state.nc.us/NEFinalEECAFactSheet.pdf. July 2004. 6 pages. 

32. Stanley, Jeanette, NC Superfund Section. Memo to File, Subject: Sigma Recycling aka 

Wilmington Resources site. March 31, 2010. 202 pages. 

33. Kowalski, Stacy, OTIE. Email correspondence with Rich Carpenter, Director, 

NCDENR, Division of Marine Fisheries, Subject: NE Cape Fear river in Wilmington – 

Commercial Fisheries. February 10, 2010. 2 pages. 

34. Goddard, Denise, USEPA. Memo to Roger Carlton, Subject: Final Analytical Report, 

Project: 09-0495, Horton Iron. June 1, 2010. 6 pages. 

35. Bryson, Melanie and Jim Bateson, NC Superfund Section. Sampling and Analysis 

Plan/Quality Assurance Project Plan. February 11, 2003. 8 pages. 
8 

HORTON IRON & METAL CO. 

WILMINGTON, NEW HANOVER COUNTY, NC 

LIST OF FIGURES 

Figure 1. Facility Location Map, Base: US Geological Survey, 7.5-minute topographic 

quadrangle map of Castle Hayne, NC, 1997, prepared by NCDWM. March 16, 

2010. 

Figure 2. Nearby Facilities, prepared by NCDWM. March 16, 2010. 

Figure 3. Source Area, prepared by NCDWM. March 16, 2010. 

Figure 4. Surface and Subsurface Soil Sample Locations, prepared by NCDWM. March 

16, 2010. 

Figure 5. Deep Subsurface Soil Sample Locations, prepared by NCDWM. March 16, 2010. 

Figure 6. Sediment Sample Locations, prepared by NCDWM. March 16, 2010. 

Figure 7. Groundwater, Surface Water/Sediment, prepared by NCDWM. February 7, 2003. 

Figure 8. Surface Water/Sediments, prepared by NCDWM. February 7, 2003. 
77°58'0"W 77°57'30"W 77°57'0"W 77°56'30"W

Facility

Northeast Cape Fear River

NC Hwy 421

34°16'30"N 34°16'30"N

34°16'0"N 34°16'0"N

34°15'30"N 34°15'30"N

77°58'0"W 77°57'30"W 77°57'0"W 77°56'30"W

1:15,000

Site Name:

Site Number: μ

Scale:

Date:

Prepared by:

Facility Location Map

NCN000407480

March 16, 2010

County Location Map Extent: New Hanover County

USGS 7.5 Minute Topographic Quadrangle:

Coordinates of approximate center of Horton Property:

Longitude: Latitude:

Castle Hayne, 1997

34o 77 15' 59.94'' o 57' 14.70''

77.9541o 35.2664o Figure 1

Horton Iron & Metal Co.
 

 

 

 

 

 

 

 

 

34°16'30"N 34°16'0"N 

77°57'30"W 

77°57 30 W NC Hwy 421 

HORTON IRON & METAL CO.

NCN000407480 

SIGMA RECYCLING 

NCR000136192 

V.C. CHEMICAL-ALMONT WORKS

NC0002178580 

NORTHEAST CHEMICAL COMPANY SITE 

NCSFN0406973 

77°56'30"W 

77°56 30 W 

77°57'0"W 

77°57 0 W 

34°16'30"N 34°16'0"N 

Northeast Cape Fear River 

County Location Map Extent:

New Hanover County 

This figure includes information from 

the following:

Ref

Re 

erence 4 

ference 20 

Aerial base is 2006 imagery available from 

New Hanover County, at www.nhcgov.com. 

Nearby Facilities 

Site Name: Horton Iron & Metal Co. 

Site Number: NCN000407480 

Scale: 1:12,000 

Date: March 16, 2010 

Figure 2 Prepared by: 

' " ' " ' "
 

HI26

HI11

HI12

HI15

HI18

HI20

HI19

HI21

HI22

HI27

HI28 HI29

HI30 HI35

HI36

HI37

HI38 HI39

1:2,400 

HI40

HI41

HI16

HI05c

HI06d HI09d

HI12b

HI17b

HI31a

HI17c HI20b

HI28b

HI32a

HI33a

HI34a

HI18d

HI01BG

179,622 Sq. Ft. (4.12 acres ) 

34°16'0"N 34°16'0"N 

Aerial base is 2006 imagery available from New Hanover County, at www.nhcgov.com Source area was calculated using the ArcGIS Calculate Geometry Function 

Site Name: 

Site Number: μ

Scale: 

Date: 

Prepared by: 

NCN000407480 

March 16, 2010 

County Location 

Map Extent: 

New Hanover 

County Figure 

Horton Iron & Metal Co. 

Legend 

Source Area 

Sample Locations 

!( Soil 

#* Sediment 

3 

Source Area 

This figure includes 

information from the following: 

Reference 5, pp. 79 - 237 
!(

!(

!(

!( !(

!( !(

!(

!(

!(

!(

!(

!(

!( !(

!( !(

!(

!(

HI26

HI11

HI12

HI15

HI20

HI21

HI22

HI27 HI35

HI16

HI06d HI09d

HI12b

HI17b

HI32a

HI33a

HI34a

HI18d

HI01BG

1:2,400 

Site Name: 

Site Number: 

Scale: μ Date: 

Prepared by: 

NCN000407480 

March 16, 2010 

County Location Map Extent: 

New Hanover County 

Figure 

Horton Iron & Metal Co. 

Legend 

!( Sample Locations 

4 

Surface and Subsurface Soil Sample Locations 

This figure includes 

information from the following: 

Reference 5, pp. 79 - 237 

Reference 13, pp. 1 - 2 

34°16'0"N 34°16'0"N

Aerial base is 2006 imagery available from New Hanover County, at www.nhcgov.com 
1:2,400

Site Name:

Site Number:

Scale: μ Date:

Prepared by:

NCN000407480

March 16, 2010

County Location Map Extent:

New Hanover County

Figure

Horton Iron & Metal Co.

Legend

")Sample Locations

Fmr. Lead Acid Chamber

5

Deep Subsurface Soil Sample Locations

This figure includes

information from the following:

Reference 5

Reference 11

Reference 13

")

")

")

")

")

") ")

")

HI11

HI20

HI27

HI12b

HI17b

HI33a

HI18d

HI01BG

Aerial base is 2006 imagery available from New Hanover County, at www.nhcgov.com

34°16'0"N 34°16'0"N
1:2,400 

Site Name: 

Site Number: 

Scale: μ Date: 

Prepared by: 

NCN000407480 

March 16, 2010 

County Location Map Extent: 

New Hanover County 

Figure 

Horton Iron & Metal Co. 

Legend

#* Background Sediment 

#* Contaminated Sediment 

#* Sediment 

Fmr. Lead Acid Chamber 

6 

Sediment Sample Locations 

This figure includes 

information from the following: 

Reference 5, pp. 79 - 237 

Reference 13, pp. 1 - 2 

#*

#*

#*#*

#*

#*

#* #*

#*

#*

#* #* #* #*

#*

#*

HI18 HI19

HI28

HI29

HI30

HI36

HI17c

HI28b

HI37

HI38 HI39

HI31a

HI20b

HI40

HI41 HI05c

PPE1

PPE2

Aerial base is 2006 imagery available from New Hanover County, at www.nhcgov.com 

34°16'0"N 34°16'0"N 
• 

:; 

of 

:!.

•

" W HIM-008-MW Z A • . 

I 

Site: Horton Iron & Metal Figure 7 (Refs. 13, 23, 25) 

WlImlngton, New Hanover Coun Drawn By: MDB 

ApproximateScale: 1"=150' Groun<lwal8r, Surfac<> WaI8r1Sodlmon\$ 

US EPA ID #: NCN 000 407 480 Date: 217/03 
I ":.-­ -:-~-- ­ ---

"-;';:-:-"",~h -­ .~-- .. -­- . -­ -. .._­ -

• 

AVA Site: Horton Figure 8 Iron & Metal 

US EPA ID #: NCN 000 407 480 Date: 0217103 

Wilmington, N_ Hanover County D.-nBy:MDB NCDENR Approximate Scale: 1:24,000 Surface WaIlIrlSedlments 

Source: Castle Hayne, 1997 7.5­

Minute Topographic Quadrangle 

Map ofNorth Carolina Refs. 13. 23. 25 
SITE DESCRIPTION 

 The Horton Iron & Metal Co. is located at 2216 US Highway 421 N along the west bank 

of the Northeast Cape Fear River in Wilmington, New Hanover County, NC (Fig. 1). The 

property occupies approximately 38 acres and is currently operated as a scrap iron and metal 

recycler (Ref. 5, p. 77; Ref. 9, pp. 1-4; Ref. 10, pp. 2-5). Horton Iron & Metal Co. is bordered by 

the VC Chemical – Almont Works site (EPA ID # NC0 002 178 580) to the north, the Northeast 

Cape Fear River to the east, Sigma Recycling (EPA ID # NCR 000 136 192) to the south, and 

US Highway 421 N to the west (Fig. 2). 

 For HRS purposes, the site consists of areas of contaminated soils located east of the 

railroad tracks on the Horton Iron & Metal Co. property and associated releases (Figs. 3, 6, 7). 

Samples used for this documentation were collected April 1, 2003 and August 3-5, 2009 and 

were collected according to the Sampling and Analysis Plan and Quality Assurance Project Plans 

(Ref. 4, pp. 78-89, 283-284; Ref. 5, pp. 78-195; Ref. 11, pp. 1-26; Ref. 35, pp. 1-8). 

OPERATIONAL AND REGULATORY HISTORY 

The property was owned by the American Agricultural Chemical Company from 1911 

until 1949 and by Naco Fertilizer Company from 1949 through 1954 (Ref. 12, pp. 8, 9, 13, 14). 

Fertilizer operations began on the property by 1915, as indicated by a 1915 Sanborn Map. 

According to this map, American Agricultural Chemical Company had an acid chamber building 

on the northwest corner of the fertilizer operations. A 1951 Sanborn Map does not show an acid 

chamber at the same property then owned by Naco Fertilizer Company (Ref. 13, pp. 1, 2). 

During the time of fertilizer operations at the facility, acid chambers were typically lined with 

lead (Ref. 14, pp. 1, 2, 12, 13, 29, 53). 

 

W.R. Grace owned the property from 1954 until 1959, when it sold the property to 

Horton Iron & Metal. In 1962, Horton Iron & Metal leased the property to Horton Industries 

(Ref. 12, pp. 16-21). In the 1960’s, the boat slips were dredged out and dredged material was 

placed on the property, along the northern, western, and southern edges of the slips (Ref. 15). 

During the 1960’s and 1970s, Horton Industries conducted ship breaking of WWII Liberty ships 

in the two slips located on the property. (Ref. 12, p. 1; Ref. 16, p. 1; Ref. 17, pp. 1, 3). 

PREVIOUS INVESTIGATIONS 

 In 1988, the U.S. Coast Guard found extensive oil staining around the metal crushing 

equipment on the property. A Notice of Violation (NOV) was issued in 1989, ordering a ground 

water investigation and soil removal. The oil-stained soils were removed, and an underground 

storage tank (UST) removal was conducted in 1996 (Ref. 12, p. 1; Ref. 18, pp. 66, 67). 

 Based on the facility history, potential human exposure to contaminated soil, and the 

potential of facility operations to release contaminants to the Northeast Cape Fear River, the NC 

Superfund Section recommended this site for addition to CERCLIS on April 29, 2002 (Ref. 19, 

pp. 1-6). The site was added to CERCLIS on July 11, 2002 (Ref. 20, p. 2). 

17 
 The Abbreviated Preliminary Assessment (APA) Checklist for the site was completed by 

the NC Superfund Section on February 11, 2003. The APA Checklist recommended the site for 

a higher priority Site Investigation (SI) based on the potential for lead and other contaminants in 

the site soils (Ref. 21, p. 2). No SI has been identified to have occurred at the site (Ref. 20, p. 2). 

The site was tasked for an Expanded Site Investigation (ESI) on CERCLIS (Ref. 20, p. 2). 

On January 8, 2003 and March 5, 2003, the NC Superfund Section conducted 

reconnaissance activities at the property (Ref. 17, pp. 1-3; Ref. 22, pp. 1, 2). During the week of 

March 17, 2003 and prior to the ESI sampling event the EPA Science and Ecosystem Support 

Division (SESD) and personnel from the NC Superfund Section installed six monitoring wells on 

the Horton property. Two wells were installed in the area of the former acid chamber. Three 

wells were installed directly south and southeast of the former acid chamber area, and one well 

was installed on the property owned by Horton on the west side of Highway 421 (Ref. 23, pp. 1-

4; Ref. 24, pp. 1-9). 

The NC Superfund Section conducted an ESI sampling event at the property on April 1-

2, 2003. Personnel collected nine surface water and ten sediment samples, including one 

background surface water sample and two background sediment samples. The sediment and 

surface water samples were collected from both slips located on the property as well as upstream 

and downstream of the property along the Northeast Cape Fear River. Eight three-point 

composite surface soil samples were collected from the area of the former acid chamber and the 

area of the former ship-breaking operations to determine the presence or absence of 

contaminated soils and delineate the potential source at the property. A total of eight ground 

water samples were collected: six from the newly installed monitoring wells (including one 

background well) and two from on-site supply wells (Ref. 4, pp. 6, 13, 20; Ref. 25, pp. 1-27). 

Soil samples indicated elevated (as compared to background) levels of metals, polycyclic 

aromatic hydrocarbons (PAHs), pesticides, and polychlorinated biphenyls (PCBs), as well as 

detectible levels of asbestos. Several constituents also exceeded both federal health-based 

benchmarks and NC Soil Remediation Goals (NCSRGs). Arsenic was detected above federal 

and state benchmark values in seven of the eight samples, with concentrations ranging from 35 to 

240 milligrams per kilogram (mg/kg). All eight samples contained levels of lead above the 

NRSRG of 400 mg/kg, with concentrations ranging from 1,300 to 23,000 mg/kg. In addition, 

antimony, total mercury, and several PAHs also exceeded their federal health-based screening 

levels in at least one sample. Cadmium, chromium, thallium, vanadium, total mercury, and 

several PAHs exceeded their NCSRG in at least one sample (Ref. 4, pp. 12-17). 

Ground water samples indicated elevated levels of several metals, as compared to 

background levels, including arsenic, cadmium, copper, lead, nickel, and zinc (as well as some 

pesticides in one sample). Of these contaminants, arsenic and antimony were detected at levels 

which exceeded EPA health-based benchmarks in at least one sample, while arsenic and nickel 

were detected at levels which exceeded NC Administrative Code’s Title 15A, Subchapter 2L 

ground water standards (Ref. 4, pp. 19-23). 

18 
Surface water samples indicated elevated levels (as compared to background levels) of 

arsenic (4.4 to 5,900 microgram per liter (ug/l)), copper (42 to 9,200 ug/l), lead (87 to 21,000 

ug/l), mercury (0.23 to 130 ug/l), and zinc (110 to 49,000 ug/l) in several samples. Sediment 

samples indicated the presence of arsenic (as high as 190 mg/kg), cadmium (as high as 2.7 

mg/kg), copper (as high as 360 mg/kg), lead (as high as 890 mg/kg), and mercury (as high as 2.7 

mg/kg) in more than one sample (Ref. 4, pp. 24-31). Based on the elevated levels of constituents 

of concern on the property and in the Northeast Cape Fear River, the site was recommended for 

further action under CERCLA (Ref. 4, pp. 33, 34). 

A Removal Assessment (RA) was conducted by Tetra Tech, the Superfund Technical 

Assistance & Response Team (START) contractor for EPA, at the property in January 2007. 

The RA was conducted to delineate areas of contamination and assess the need for a removal 

action. During the RA, eighty composite surface soil locations (0 to 6 inches below ground 

surface (bgs)) on the property were screened for arsenic and lead using a X-Ray Fluorescence 

(XRF) instrument, and ten confirmatory samples were shipped to a laboratory to confirm the 

screening results. Samples were collected from 100’ x 100’ grids cells located in the former lead 

acid chamber area and in the northern and southern portions of the property. Additionally, ten 

surface soil samples were collected from the property for PCB analysis (Ref. 26, pp. 1, 2). 

Results of the XRF screening indicated lead concentrations ranging from 17.2 parts per million 

(ppm) to 11,800 ppm. Arsenic screening results indicated concentrations from less than 13.0 

ppm to 474 ppm. Thirty seven locations exceeded the EPA Removal Action Levels (RALs) for 

lead (1,200 ppm) and/or arsenic (160 ppm). Confirmation samples analyzed by the laboratory 

confirmed the results and indicated that an additional five locations exceeded the EPA RAL for 

lead. All of the elevated levels of lead and arsenic were located in the area of the former lead 

acid chamber and in several grids between the northern and southern boat slips. The ten samples 

collected for PCB analysis indicated concentrations ranging from 78J parts per billion (ppb) to 

3,800 ppb; however, no samples exceeded the EPA RAL for PCBs (Ref. 26, pp. 2-4, 7, 12-16). 

On April 28, 2009, personnel from EPA, EPA START contractor Oneida Total Integrated 

Enterprises (OTIE), and NC conducted a reconnaissance at the property (Ref. 5, pp. 75-77). An 

ESI sampling event, performed by personnel from the same entities, was conducted during the 

week of August 3, 2009. Sampling for this event included: 14 ground water samples (eight 

temporary well samples and six permanent monitoring well samples), including one background 

sample for each type of well; 20 surface soil samples, 15 subsurface soil samples, and eight deep 

subsurface soil samples, including background samples for each depth interval; and 17 sediment 

samples, including one background sample (Ref. 5, p.12). 

Asbestos was detected in several soil samples located around the slips, and elevated (as 

compared to background) concentrations of constituents were detected in all media collected 

during the investigation. PCBs, PAHs, volatile organic compounds (VOCs), lead, arsenic, 

cadmium, and mercury were detected in surface and subsurface soil samples. Deep subsurface 

soil samples (8 to 12 feet below ground surface (bgs)) indicated the presence of metals, including 

lead and arsenic. Sediment samples collected from the two slips indicated elevated levels of 

PCBs, PAHs, mercury, arsenic, and lead. Ground water samples indicated arsenic, cadmium, 

and lead in the ground water beneath the property (Ref. 5, pp. 15-18, 26, 29-33, 35-70). 

19 
20 

A second ESI report, based on the August 2009 data, was completed by OTIE on March 

3, 2010. Based on the data gathered during the ESI, including the release of contaminants to the 

slips along the Northeast Cape Fear River, a fishery, the site was recommended for further 

evaluation and possible inclusion on the National Priorities List (NPL) (Ref. 5, pp. 19, 20). 
SOURCE CHARACTERIZATION

2.2 Source Identification

Number of the Source: 1 

Name and description of the source: Contaminated soil 

The source is defined as the area of contaminated soils bounded by surface soil samples 

documented in Tables 1-3 and shown on Figure 3 of this HRS documentation record. Areas 

comprising this bounded portion include the former lead acid chamber area, former shipbreaking operations, and areas where materials dredged from the slips were placed during the 

1960s (Ref. 12, p. 1; Ref. 13, p. 1; Ref. 15, p. 1; Ref. 17, pp. 1, 3). 

In January 2007, the entire eastern portion of the Horton property was gridded and 

sampled for arsenic, lead, and PCBs. Grab soil samples from 80 grid locations were screened 

with an XRF unit; concentrations at 37 locations exceeded the EPA industrial removal action 

levels (RALs) for lead (1,200 ppm) and/or arsenic (160 pm) (Ref. 26, pp. 8, 9, 12-14). 

At ten of these locations, soil samples were collected from depths of 0 to 6 inches and 

analyzed for lead and arsenic for laboratory confirmation. Lead concentrations ranged from 720 

ppm in sample HIM-SS-10 to 2,400 ppm in sample HIM-SS-04. Arsenic concentrations ranged 

from 7.3J ppm in sample HIM-SS-10 to 82J ppm in sample HIM-SS-04. Ten soil samples were 

also collected for PCB analysis in areas where ship-breaking operations occurred. PCB-1254 

concentrations ranged from 78J parts per billion (ppb) in sample HIM-PCB-04 to 3,800 ppb in 

sample HIM-PCB-10. PCB-1262 concentrations, where detected, ranged from 90 ppb to 1,900 

ppb (Ref. 26, pp. 3, 7, 15, 16). 

Additional documentation of source hazardous substances is presented in Section 2.4.1 of 

this HRS documentation record. 

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

This source is located on the eastern portion of the property, between the railroad tracks 

and the Northeast Cape Fear River (Fig. 3). 

21 
22 

Containment

Release via overland migration and/or flood – 

There is no maintained engineered cover or functioning and maintained run-on control 

system and runoff management system, and contaminated soil is available for continuous and 

ongoing overland flow (Ref. 1, Table 4-2; Ref. 25, pp. 12, 14, 15, 20-22). 

Section 4.1.2.1.1 of this documentation record documents an observed release of site 

contaminants to the Northeast Cape Fear River (Ref. 1; Ref. 5, pp. 32, 33, 59-67). 

Containment factor: 

This information, applied to Table 4-2 in Reference 1, yields a containment value of 10. 
23 

2.4 Waste Characteristics 

2.4.1 Hazardous Substances

From the early 1900s up until the 1950s, the property was used for fertilizer operations 

(Ref. 12, pp. 8, 9, 13, 14; Ref. 13, pp. 1, 2). Typically, sulfuric acid was manufactured by 

roasting pyrites to drive off the sulfur in gaseous form, which was reacted with water in the lead 

chambers to form the acid. Where pyrite ore is roasted, there will be a residue (cinders) which 

may contain a wide range of heavy metals. During this time period, acid chambers were 

typically lined with lead. Lead-bearing spent acid released from the chambers after treatment of 

the phosphate rock typically resulted in lead-contaminated, low-pH soils. Some contaminants 

associated with fertilizer operations during this time period include arsenic, cadmium, copper, 

lead, mercury, vanadium, zinc, platinum, and asbestos (Ref. 14, pp. 1-54; Ref. 27, pp. 1, 2).

During the 1960s and 1970s, Horton Industries conducted ship breaking of WWII Liberty 

ships in the two slips located on the property (Ref. 12, p. 1; Ref. 16, p. 1; Ref. 17, pp. 1, 3). 

Typical contaminants associated with ship-breaking include asbestos, PCBs, PAHs, barium, 

cadmium, chromium, copper, lead, nickel, and zinc (Ref. 28, pp. 22, 47, 65, 83, 114, 150, 170, 

171). 

During the week of August 3, 2009, personnel from EPA, NC, and OTIE conducted an 

ESI sampling event at the property. Samples were collected according to the Quality Assurance 

Project Plan (QAPP) developed by EPA Region 4 Science and Ecosystem Support Division (Ref. 

11, pp. 1-26; Ref. 5, p. 11). Samples were shipped to Contract Laboratory Program (CLP) 

laboratories and analyzed for total metals and mercury by ICP-AES by Statement of Work 

(SOW) ILM05.4 and volatiles, semi-volatile extractables, and aroclors by SOW SOM01.2 (Ref. 

5, pp. 12, 239-259, 263, 264; Ref. 34, pp. 1-6). An EPA Region 4 Science and Ecosystem 

Support Division Quality Assurance Chemist reviewed and validated this data for performance 

according to the Statements of Work (Ref. 34, pp. 1-6). Source soil sampling for this event 

included 18 surface soil samples, 14 subsurface soil samples, and seven deep subsurface soil 

samples. In addition, four background samples, including two surface soils (HI01BGDSF and 

HI01BGSF), one subsurface (HI01BGSB), and one deep subsurface (HI01BGDSB), were 

collected (Ref. 5, pp. 11, 12, 18, 26, 115-195; Figs. 3, 4, 5). These samples are described in 

Table 1 of this HRS documentation record. 

Of the 39 source soil samples collected, 17 surface, 12 subsurface, and four deep 

subsurface samples contained at least one operations-related contaminant at an elevated level, as 

compared to background levels. All surface and subsurface soil samples were compared to both 

background surface soil samples (HI01BGDSF and HI01BGSF) and the background subsurface 

soil sample (HI01BDSB) for similarity in soil depths. All deep subsurface soil samples were 

compared to the background deep subsurface soil sample (HI01BGDSB) (Ref. 5, pp. 29, 30, 35-

58; Tables. 1, 2, 3). 

Metals were detected at elevated levels in surface, subsurface, and deep subsurface soil 

samples. Mercury (97 mg/kg, highest concentration), cadmium (35 mg/kg, highest 

concentration), nickel (380 mg/kg, highest concentration), and zinc (6,600 ug/kg, highest 

concentration) were, in general, detected at higher elevated levels in surface soil samples than in 

subsurface soil samples. Arsenic (540 mg/kg, highest concentration), copper (3,100 mg/kg, 
24 

highest concentration), and lead (14,000 mg/kg, highest concentration) were detected at higher 

elevated levels in the subsurface soil samples. Arsenic (5.0-9.2 mg/kg), cadmium (1.5-3.1 

mg/kg), copper (3.4-610 mg/kg), lead (10-68 mg/kg), and zinc (12-340) were all detected at 

elevated levels in deep subsurface soil samples (Ref. 5, pp. 29, 30, 45-48, 55-58). 

SVOCs, including PCBs, were detected at elevated levels, as compared to background 

levels, in both surface and subsurface soil samples. For the contaminants of concern for this 

HRS documentation record, no SVOCs or PCBs were detected in elevated levels in any of the 

deep subsurface soil samples. Fluoranthene (10,000 ug/kg, highest concentration), pyrene (8,300 

ug/kg, highest concentration), PCB-1260 (1,200 ug/kg, highest concentration), and PCB-1268 

(550 ug/kg, highest concentration) were detected at higher elevated levels in surface soil 

samples. PCB-1254 (1,600 ug/kg, highest concentration), however, was detected at its highest 

elevated levels in subsurface soil samples (Ref. 5, pp. 35-44, 49-54, 58). 

Although there is a large number of contaminants identified in source samples, 

documentation of hazardous substances is limited to the following contaminants which were 

selected to represent the source: arsenic, cadmium, copper, lead, mercury, nickel, zinc, 

fluoranthene, pyrene, PCB-1254, PCB-1260, and PCB-1268. 

Table 1. Source and Background Soil Sample Descriptions 

Sample ID Date Time

Sample 

Depth 

(Feet)

Sample Description References

HI01BGDSB 8/4/09 9:53 8-12

Deep subsurface soil sample located on northwest 

corner of property just east of railroad and south of 

power line; light brown wet fine sand.

Ref. 5, pp. 

170, 171

HI01BGDSF 8/3/09 14:55 0-1.5 Background surface soil sample; same as HI01BGSF. Ref. 5, pp. 

127, 128

HI01BGSB 8/3/09 14:50 1.5-3 Background subsurface soil sample; tan sand. Ref. 5, pp. 

125, 126

HI01BGSF 8/3/09 14:45 0-1.5 Background surface soil sample; organic soil (0-0.5'), 

brown sand (0.5-1.5')

Ref. 5, pp. 

125, 126

HI06dSB 8/3/09 15:40 2-4

Subsurface soil sample in depressed burn pit area, 

approximately 85' east of railroad switch; very loose 

light tan sand.

Ref. 5, pp. 

144, 145

HI06dSF 8/3/09 15:35 0-2

Surface soil sample in depressed burn pit area, 

approximately 85' east of railroad switch; very loose 

light tan sand.

Ref. 5, pp. 

144, 145

HI09dSF 8/3/09 15:10 0-1

Surface soil sample at edge of debris field north of 

eastern edge of acid chamber area; brown sand mixed 

with bricks and debris.

Ref. 5, pp. 

180, 181

HI11DSB 8/5/09 9:12 8-12

Deep subsurface soil sample located northwest of 

former lead acid chambers; light brown fine-grained 

wet sand.

Ref. 5, pp. 

188, 189
25 

Sample ID Date Time

Sample 

Depth 

(Feet)

Sample Description References

HI11SB 8/4/09 8:40 2-4 Subsurface soil sample near northwest corner of 

property; light tan sand with orange mottling.

Ref. 5, pp. 

146, 147

HI11SF 8/4/09 8:30 0-2 Surface soil sample near northwest corner of property; 

light tan sand with orange mottling from 4"-2'.

Ref. 5, pp. 

146, 147

HI12bSB 8/4/09 10:12 2-4

Surface soil sample located approximately 125' north 

of two-story shop building; light tan sand with orange 

mottling.

Ref. 5, pp. 

150, 151

HI12bSF 8/4/09 10:05 0-2

Surface soil sample located approximately 125' north 

of two-story shop building; dark brown sand (0-3"), tan 

sand (3"-2').

Ref. 5, pp. 

150, 151

HI12DSB 8/5/09 8:50 8-12

Deep subsurface soil sample located northeast of 

former lead acid chambers and existing structures; light 

brown medium-grained wet sand.

Ref. 5, pp. 

186, 187

HI12SB 8/4/09 9:15 2-4

Subsurface soil sample north of slab area on northern 

portion of property; white sand (2-3.5'), tan sand with 

orange mottling (3.5-4').

Ref. 5, pp. 

148, 149

HI12SF 8/4/09 9:05 0-2

Surface soil sample north of slab area on northern 

portion of property; dark brown sand (0-1'), tan sand 

with orange mottling (1-2').

Ref. 5, pp. 

148, 149

HI15SB 8/3/09 11:14 2-4

Subsurface soil sample in small clearing on northeast 

corner of property in a wooded area; brown silty fine to 

medium sand with red clay mixed in from 3-4'.

Ref. 5, pp. 

156, 157

HI15SF 8/3/09 10:52 0-2

Surface soil sample in small clearing on northeast 

corner of property in a wooded area; brown silty fine to 

medium sand.

Ref. 5, pp. 

154, 155

HI16SB 8/3/09 13:05 1.5-3 Subsurface soil sample approximately 120' east of 

railroad tracks and 20' north off roadway; tan sand.

Ref. 5, pp. 

123, 124

HI16SF 8/3/09 12:50 0-1.5

Surface soil sample approximately 120' east of railroad 

tracks and 20' north off roadway; organic silty sands 

mixed with small rocks and coal.

Ref. 5, pp. 

123, 124

HI17bDSB 8/4/09 13:20 8-12

Deep subsurface soil sample located on north side of 

interior of northern slip; light brown medium sand with 

reddish brown sand in bottom 6".

Ref. 5, pp. 

184, 185

HI17bSB 8/3/09 11:40 2-4

Subsurface soil sample approximately 15' north of 

northwest corner of northern slip; light tan moist sand 

(2-3.5'), dark sand (3.5-4').

Ref. 5, pp. 

134, 135

HI17bSF 8/3/09 11:25 0-2

Surface soil sample approximately 15' north of 

northwest corner of northern slip; dark sand (0-1.5'), 

light tan sand (1.5-2').

Ref. 5, pp. 

134, 135

HI18dDSB 8/4/09 13:00 8-12

Deep subsurface soil sample located along north side of 

north slip; light gray to white medium wet sand 

changing to black peaty clay at depth (12').

Ref. 5, pp. 

182, 183
26 

Sample ID Date Time

Sample 

Depth 

(Feet)

Sample Description References

HI18dSB 8/3/09 11:30 1.5-2

Subsurface soil sample 40' north of north side of 

northern slip, approximately 40' south of middle of 

cinder block building; fine sand mixed with 

metals/aggregates.

Ref. 5, pp. 

121, 122

HI18dSF 8/3/09 11:20 0-1.5

Surface soil sample 40' north of north side of northern 

slip, approximately 40' south of middle of cinder block 

building; fine sand mixed with organic silts.

Ref. 5, pp. 

121, 122

HI20DSB 8/4/09 11:10 8-12

Deep subsurface soil sample located on northwest 

corner of property just east of railroad and south of 

power line; dark brown wet fine to medium sand.

Ref. 5, pp. 

172, 173

HI20SB 8/3/09 10:55 2-3 Subsurface soil sample along north side of northern 

slip, as far east as possible to reach; dark silty sand.

Ref. 5, pp. 

132, 133

HI20SF 8/3/09 10:40 0.5-1.5

Surface soil sample along north side of northern slip, as 

far east as possible to reach; dark silty sand mixed with 

organics.

Ref. 5, pp. 

132, 133

HI21SB 8/3/09 14:10 2-4

Subsurface soil sample located south of concrete pad 

just east of railroad tracks adjacent to area between the 

two slips; tan sand (24-30"), magenta sand (30-38"), 

brown sand (38-48").

Ref. 5, pp. 

178, 179

HI21SF 8/3/09 13:40 0-2

Surface soil sample located south of concrete pad just 

east of railroad tracks adjacent to area between the two 

slips; dark brown sand (0-1'), tan sand (1-2').

Ref. 5, pp. 

176, 177

HI22bSF 8/3/09 14:45 0-0.67 Soil sample along north side of pier between the two 

slips; brown fine silty sand mixed with roots.

Ref. 5, pp. 

166, 167

HI26SB 8/3/09 12:50 2-3 Subsurface soil sample on promontory of dock between 

slips; light brown fine sand.

Ref. 5, pp. 

160, 161

HI26SF 8/3/09 12:36 0-2 Surface soil sample on promontory of dock between 

slips; brown fine sand.

Ref. 5, pp. 

158, 159

HI27DSB 8/5/09 10:00 8-12 Deep subsurface soil sample located southwest of 

southern slip; light brown fine-grained wet sand.

Ref. 5, pp. 

190, 191

HI27SB 8/3/09 14:40 2-4

Subsurface soil sample located off southwest corner of 

southern slip; medium tan sand mixed with glass shards 

(2-3'), light tan sand (3-4').

Ref. 5, pp. 

142, 143

HI27SF 8/3/09 14:25 0-2

Surface soil sample located off southwest corner of 

southern slip; medium tan sand with glass shards mixed 

in from 0.5 to 2' deep.

Ref. 5, pp. 

142, 143

HI32aSB 8/3/09 14:05 2-4

Subsurface soil sample located south of the southern 

slip, approximately 1/4 of the length from end of slip 

towards the river and 15' south; light gray sand with 

orange mottling at 2.5'.

Ref. 5, pp. 

140, 141
27 

Sample ID Date Time

Sample 

Depth 

(Feet)

Sample Description References

HI32aSF 8/3/09 13:55 0-2

Surface soil sample located south of the southern slip, 

approximately 1/4 of the length from end of slip 

towards the river and 15' south; dark sand.

Ref. 5, pp. 

140, 141

HI33aDSB 8/5/09 10:20 8-12

Deep subsurface soil sample located south of the 

approximate middle of the southern slip; dark gray fine 

sand (8-8.5'), black silty clay (8.5-9.5'), black peat 

mixed with wood pieces (9.5-12').

Ref. 5, pp. 

192, 193

HI33aSF 8/3/09 12:45 0-2

Surface soil sample located south of the southern slip, 

approximately 1/2 of the length towards the river and 

40' south; medium tan sand mixed with organics (0-1'), 

dark brown sand mixed with roots and wood chips (1-

2').

Ref. 5, pp. 

138, 139

HI34aSF 8/3/09 12:25 0-2

Surface soil sample located south of the southern slip, 

approximately 3/4 of the length towards the river from 

rear of slip and 20' south; medium brown sand (0-1'), 

mix of light tan and dark tan sand (1-2').

Ref. 5, pp. 

136, 137

HI35SB 8/5/09 8:55 2-4

Subsurface soil sample at tip of land mass on south of 

southern slip in a slight depression; dark silty sand (2-

3'), stiff black clay (3-3.5'), dark silty sand (3.5-4').

Ref. 5, pp. 

116, 117

HI35SF 8/5/09 8:45 0-2 Surface soil sample at tip of land mass on south of 

southern slip in a slight depression; dark silty sand.

Ref. 5, pp. 

116, 117
28 

Table 2. Source Soil Samples-Inorganic Data 

Sample ID Contaminant Concentration 

(mg/kg)

SQL* 

(mg/kg) References

Mercury 0.035UJ(0.10U)1,2 0.10

Arsenic 4.8 1.0

Cadmium 0.28J(0.51U) 1 0.51

Copper 18 2.5

Lead 96 1.0

Nickel 2.4J(4.0U) 1 4.0

HI01BGDSF

(Background)

Zinc 23 6.1

Ref. 5, pp. 241, 

262-265, 268, 275

Mercury 0.11U 0.11

Arsenic 1.1U 1.1

Cadmium 0.53U 0.53

Copper 1.2J(2.7U) 1 2.7

Lead 3.6 1.1

Nickel 4.2U 4.2

HI01BGSB

(Background)

Zinc 7.2 6.4

Ref. 5, pp. 241, 

262-265, 268, 277

Mercury 0.11U 0.11

Arsenic 1.4J(2.4) 3 1.1

Cadmium 0.54U 0.54

Copper 6.4 2.7

Lead 28 1.1

Nickel 4.3U 4.3

HI01BGSF

(Background)

Zinc 22 6.4

Ref. 5, pp. 241, 

262-265, 268, 

278; Ref. 8, pp. 8, 

18

Mercury 17 0.37

Arsenic 26 1.2

Cadmium 35 0.62

Copper 2,200 3.1

Lead 5,500 1.2

Nickel 380 5.0

HI09dSF

Zinc 4,600 7.4

Ref. 5, pp. 242, 

262-265, 282

Cadmium 0.64 0.51

Copper 93 2.5

Nickel 22 4.0

HI11SF

Zinc 100 6.1

Ref. 5, pp. 242, 

262-265, 286

Mercury 0.70 0.10

Arsenic 34 0.97

Cadmium 0.60 0.48

HI12bSF

Copper 110 2.4

Ref. 5, pp. 243, 

262-265, 292
29 

Sample ID Contaminant Concentration 

(mg/kg)

SQL* 

(mg/kg) References

Lead 440 0.97

Zinc 120 5.8

Mercury 97 2.1

Arsenic 28 1.0

Cadmium 6.2 0.51

Lead 3,300 1.0

HI12SF

Zinc 170 6.2

Ref. 5, pp. 242, 

262-265, 289

Mercury 0.31 0.12

Arsenic 33 1.2

Cadmium 1.4 0.60

Copper 200 3.0

Nickel 5.2 4.8

HI15SF

Zinc 280 7.2

Ref. 5, pp. 239, 

262-265, 294

HI16SB Mercury 0.76 0.099 Ref. 5, pp. 240, 

262-265, 295

Mercury 1.7 0.10

Arsenic 98 1.0

Cadmium 4.3 0.52

Copper 550 2.6

Lead 1,400 1.0

Nickel 14 4.1

HI16SF

Zinc 920 6.2

Ref. 5, pp. 240, 

262-265, 296

Mercury 0.62 0.10

Arsenic 63 1.1

Cadmium 1.7 0.54

Copper 450 2.7

Lead 680 1.1

HI17bSF

Zinc 910 6.5

Ref. 5, pp. 239, 

262-265, 299

Mercury 1.0 0.12

Arsenic 540 1.2

Cadmium 13 0.58

Copper 3,100 2.9

Lead 13,000 1.6

Nickel 14 4.7

HI18dSB

Zinc 5,400 7.0

Ref. 5, pp. 239, 

262-264, 266, 304
30 

Sample ID Contaminant Concentration 

(mg/kg)

SQL* 

(mg/kg) References

Mercury 2.1 0.11

Arsenic 150 1.1

Cadmium 5.7 0.53

Copper 1,100 2.6

Lead 2,600 1.1

Nickel 11 4.2

HI18dSF

Zinc 1,300 6.3

Ref. 5, pp. 239, 

262-264, 266, 306

Mercury 0.15 0.11

Cadmium 0.65 0.58

Copper 99 2.9

HI20SF

Zinc 140 6.9

Ref. 5, pp. 239, 

262-264, 266, 311

Mercury 0.26 0.11

Cadmium 3.2 0.53

Copper 200 2.7

Lead 1,500 1.1

Nickel 50 4.3

HI21SF

Zinc 1,600 6.4

Ref. 5, pp. 240, 

262-264, 266, 314

Mercury 8.6 0.22

Arsenic 56 1.1

Cadmium 20 0.54

Copper 790 2.7

Lead 6,200 1.1

Nickel 170 4.3

HI22bSF

Zinc 6,600 6.5

Ref. 5, pp. 241, 

262-264, 266, 315

Mercury 1.0 0.10

Cadmium 0.84 0.52

Nickel 9.6 4.1

HI26SF

Zinc 200 6.2

Ref. 5, pp. 240, 

262-264, 266, 317

Mercury 0.36 0.10

Cadmium 3.4 0.52

Copper 150 2.6

Lead 700 1.0

Nickel 34 4.1

HI27SF

Zinc 2,300 6.2

Ref. 5, pp. 241, 

262-264, 266, 320
31 

Sample ID Contaminant Concentration 

(mg/kg)

SQL* 

(mg/kg) References

Mercury 1.4 0.11

Cadmium 3.2 0.54

Copper 120 2.7

Lead 800 1.1

Nickel 14 4.3

HI32aSF

Zinc 1,100 6.5

Ref. 5, pp. 241, 

262-264, 266, 328

Mercury 0.36 0.11

Cadmium 1.9 0.53

Copper 62 2.7

Lead 490 1.1

Nickel 26 4.3

HI33aSF

Zinc 930 6.4

Ref. 5, pp. 240, 

262-264, 266, 331

Mercury 0.15 0.11

Cadmium 2.0 0.54

Copper 270 2.7

Nickel 7.4 4.3

HI34aSF

Zinc 340 6.5

Ref. 5, pp. 240, 

262-264, 266, 332

Mercury 0.22 0.13

Arsenic 35 1.3

Cadmium 2.3 0.63

Copper 100 3.2

Lead 360 1.3

Nickel 14 5.0

HI35SF

Zinc 560 7.6

Ref. 5, pp. 244, 

262-264, 266, 334

* SQLs are the sample-specific quantitation limits as reported as the MRLs (Minimum 

Reporting Limits) on the analytical data sheets. Each SQL corresponds to the lowest 

demonstrated level of acceptable quantitation and is adjusted for the amount of sample 

prepared, dilution performed, and percent moisture in the source samples (Ref. 5, p. 268). 

U – The analyte was not detected at or above the reporting limit (Ref. 5, p. 268). 

J – The identification of the analyte is acceptable; the reported value is an estimate (Ref. 5, 

p. 268). 

1 – Result is greater than Method Detection Limit (MDL) but less than MRL. The number 

shown in ( ) is the SQL. 

2 – Concentration reported is less than the lowest standard on calibration curve. The 

number shown in ( ) is the SQL. 

3 – Bias is unknown. Therefore, value is adjusted accordingly per Ref. 8. The number 

shown in ( ) is the adjusted value. 
32 

Table 3. Source Soil Samples-Organic Data 

Sample ID Contaminant Concentration 

(ug/kg)

SQL* 

(ug/kg) References

Fluoranthene 170J(170U) 1 170

Pyrene 140J(170U) 1 170

PCB-1254 33U 33

PCB-1260 33U 33

HI01BGDSF

Background

PCB-1268 33U 33

Ref. 5, pp. 250, 526, 529, 540, 

541, 761, 768

Fluoranthene 170U 170

Pyrene 170U 170

PCB-1254 34U 34

PCB-1260 34U 34

HI01BGSB

Background

PCB-1268 34U 34

Ref. 5, pp. 249, 526, 529, 546, 

547, 761, 764, 770

Fluoranthene 43J(170U) 1 170

Pyrene 41J(170U) 1 170

PCB-1254 33U 33

PCB-1260 33U 33

HI01BGSF

Background

PCB-1268 33U 33

Ref. 5, pp. 250, 526, 529, 549, 

550, 761, 771

Fluoranthene 1,400 210

Pyrene 1,200 210

PCB-1254 1,200 330

HI09dSF

PCB-1260 1,000 330

Ref. 5, pp. 250, 526, 561, 562, 

761, 775

Fluoranthene 460 170 HI12bSF

Pyrene 410 170 Ref. 5, pp. 252, 526, 591, 592

Fluoranthene 940 170

HI12SF Pyrene 860 170

PCB-1260 40 34

Ref. 5, pp. 251, 526, 582, 583, 

761, 782

Fluoranthene 4,400 360 HI16SF

PCB-1254 250 35

Ref. 5, pp. 248, 526, 529, 603, 

604, 761, 789; Ref. 8, pp. 8, 15

Fluoranthene 5,900 730 HI17bSF

PCB-1254 95 35

Ref. 5, pp. 247, 526, 529, 612, 

613, 761, 792; Ref. 8, pp. 8, 15

Fluoranthene 3,400 350

HI18dSF PCB-1260 1,000 680

PCB-1268 110 68

Ref. 5, pp. 247, 527, 529, 633, 

634, 762, 799; Ref. 8, pp. 8, 15

PCB-1254 45 38 HI20SF

PCB-1260 39 38 Ref. 5, pp. 247, 762, 804
33 

Sample ID Contaminant Concentration 

(ug/kg)

SQL* 

(ug/kg) References

HI21SF Fluoranthene 9,200 750 Ref. 5, pp. 249, 527, 529, 657, 

658; Ref. 8, pp. 8, 15

Fluoranthene 2,000 180

Pyrene 1,800 180

PCB-1254 780 250

HI22bSF

PCB-1260 1,200 250

Ref. 5, pp. 249, 527, 660, 661, 

762, 808

Fluoranthene 270 170

Pyrene 300 170

PCB-1260 890 680

HI26SF

PCB-1268 550 68

Ref. 5, pp. 248, 527, 666, 667, 

762, 810

Fluoranthene 750 170

Pyrene 690 170

PCB-1260 1,100 340

HI27SF

PCB-1268 130 34

Ref. 5, pp. 249, 527, 675, 676, 

762, 813

Fluoranthene 10,000 740

Pyrene 8,300 740

PCB-1254 250 36

HI32aSF

PCB-1260 180 36

Ref. 5, pp. 249, 527, 696, 697, 

762, 820

Fluoranthene 720 180 HI33aSF

Pyrene 660 180 Ref. 5, pp. 255, 527, 705, 706

Fluoranthene 230 180

Pyrene 270 180

PCB-1254 71 35

HI34aSF

PCB-1260 110 35

Ref. 5, pp. 248, 527, 708, 709, 

762, 824

Fluoranthene 1,900 200

HI35SF Pyrene 1,700 200

PCB-1254 55 40

Ref. 5, pp. 255, 527, 714, 715, 

762, 826

* SQLs are the sample-specific quantitation limits as reported as the MRLs (Minimum Reporting Limits) on 

the analytical data sheets. Each SQL corresponds to the lowest demonstrated level of acceptable quantitation 

and is adjusted for the amount of sample prepared, dilution performed, and percent moisture in the source 

samples (Ref. 5, p. 529). 

U – The analyte was not detected at or above the reporting limit (Ref. 5, p. 529). 

J – The identification of the analyte is acceptable; the reported value is an estimate (Ref. 5, p. 529). 

1 – Concentration reported is less than the lowest calibration standard on calibration curve; therefore, result 

is considered Non-Detect (ND). The number shown in ( ) is the SQL. 
34 

2.4.2 Hazardous Waste Quantity

2.4.2.1 Source Hazardous Waste Quantity 

2.4.2.1.1 Hazardous Constituent Quantity

Sufficient evidence does not exist to evaluate Hazardous Constituent Quantity 

2.4.2.1.2 Hazardous Wastestream Quantity

Sufficient evidence does not exist to evaluate Hazardous Wastestream Quantity 

2.4.2.1.3 Volume

Sufficient evidence does not exist to evaluate Volume 

2.4.2.1.4 Area

 

For this HRS documentation record, the source is defined as the area of contaminated soils 

bounded by 16 surface soil sample locations documented in Tables 1-3 and shown on Figure 3 of 

this HRS documentation record. Areas comprising this bounded portion include the former lead 

acid chamber area, former ship-breaking operations, and areas where materials dredged from the 

slips were placed during the 1960s (Ref. 12, p. 1; Ref. 13, p. 1; Ref. 15, p. 1; Ref. 17, pp. 1, 3). 

The square footage of the bounded area was determined using Geographic Information System 

(GIS) software, selecting the Calculate Geometry function (see Figure 3 of this HRS 

documentation record). 

In January 2007, the entire eastern portion of the Horton property was gridded and 

sampled for arsenic, lead, and PCBs only. Grab soil samples from 80 grid locations were 

screened with an XRF unit; concentrations at 37 locations exceeded the EPA industrial removal 

action levels (RALs) for lead (1,200 ppm) and/or arsenic (160 ppm). A number of these locations 

support contamination between the 16 sample locations that are used to form the boundary of the 

source (Ref. 26, pp. 8, 9, 12-14). 

At ten of the 37 locations, soil samples were collected from depths of 0 to 6 inches and 

analyzed for lead and arsenic for laboratory confirmation. Lead concentrations ranged from 720 

ppm in sample HIM-SS-10 to 2,400 ppm in sample HIM-SS-04. Arsenic concentrations ranged 

from 7.3J ppm in sample HIM-SS-10 to 82J ppm in sample HIM-SS-04. Ten soil samples were 

also collected for PCB analysis in areas where ship-breaking operations occurred. PCB-1254 

concentrations ranged from 78J parts per billion (ppb) in sample HIM-PCB-04 to 3,800 ppb in 

sample HIM-PCB-10. PCB-1262 concentrations, where detected, ranged from 90 ppb to 1,900 

ppb. Three of the samples analyzed for PCBs were collected within the boundaries shown in 

Figure 3, further supporting contamination within these boundaries (Ref. 26, pp. 3, 7, 15, 16). 

Sum (square feet) = 179,622 

Area Assigned Value (Ref. 1, Table. 2-5) = A/34,000 

Area Assigned Value = 5.28 

(Ref. 1, Section 2.4.2.1.4) 
35 

2.4.2.1.5 Source Hazardous Waste Quantity Value

The source hazardous waste quantity (HWQ) value for Source No. 1 is 5.28 (Ref. 

1, Section 2.4.2.1.5) 

Source HWQ Value = 5.28 
36 

SITE SUMMARY OF SOURCE DESCRIPTIONS

 Containment

Source No. HWQ Value Ground Water Surface Water Air/Gas Particulate 

1 5.28 NS 10 NS NS 

Sum of Source Hazardous Waste Quantity Values = 5
37 

SURFACE WATER MIGRATION PATHWAY 

4.1 Overland Flood/Migration Component 

4.1.1.1 Definition of Hazardous Substance Migration Path for Overland/Flood Component

Overland flow from the source drains towards the two slips protruding inland from the 

Northeast Cape Fear River. Flow from the source enters the slips only at their western edges, 

which are the probable points of entry (PPEs) (Ref. 23, p. 1; Fig. 6). The Northeast Cape Fear 

River flows in a southerly direction for approximately two miles from the PPE until it combines 

with the Cape Fear River. Continuing on to the south, the Cape Fear River combines with the 

Brunswick River at a point approximately 6.5 miles downstream of the PPE. The 15-mile surface 

water pathway ends just north of the intersection of the Intercoastal Waterway and the Cape Fear 

River (Ref. 3, pp. 1, 2; Ref. 5, pp. 27, 28). 

The Northeast Cape Fear River and the Cape Fear River in the vicinity of the Horton 

facility are both salt water bodies that are tidally influenced (Ref. 29, pp. 14-19, 23-38). The boat 

slips adjacent to the facility are subject to these same tidal influences (Ref. 25, p. 1). The 

estimated flow in the Northeast Cape Fear River adjacent to the site is approximately 2,400 cubic 

feet per second (cfs), making it a large stream to river (Ref. 1, Table 4-13; Ref. 30, pp. 1, 3, 5, 6). 

 
38 

4.1.2.1 Likelihood of Release

4.1.2.1.1 Observed Release

 Background concentration – Sediment

Samples from August 2009 were collected according to the Quality Assurance Project 

Plan (QAPP) developed by EPA Region 4 Science and Ecosystem Support Division (Ref. 11, pp. 

1-26). Samples were shipped to Contract Laboratory Program (CLP) laboratories and analyzed 

for total metals and mercury by ICP-AES by Statement of Work (SOW) ILM05.4 and volatiles, 

semi-volatile extractables, and aroclors by SOW SOM01.2 (Ref. 5, pp. 239-259, 269-348; Ref. 

34, pp. 1-6). An EPA Region 4 Science and Ecosystem Support Division Quality Assurance 

Chemist reviewed and validated this data for performance according to the Statements of Work 

(Ref. 34, pp. 1-6). 

Samples from April 2003 were collected according to the Quality Assurance Project Plan 

(QAPP) developed by the NC Division of Waste Management (Ref. 35, pp. 1-8). Samples were 

shipped to Contract Laboratory Program (CLP) laboratories and analyzed for total metals and 

mercury, volatiles, semi-volatile extractables, and pesticides/PCBs. An EPA Region 4 Science 

and Ecosystem Support Division Quality Assurance Chemist reviewed and validated this data for 

performance. (Ref. 4, pp. 55-284). 

HI40SD, HI40DSD, and HI41SD were collected in the Northeast Cape Fear River, 

upstream of the slips but downstream of V.C. Almont and Northeast Chemical (Ref. 5, pp. 81-86; 

Figs. 2, 6 of this HRS documentation record). HI05cSD was collected at the mouth of an 

unnamed tributary running along the northern edge of the Horton property (Ref. 5, pp. 79, 80; Fig. 

6). HIM-027-SD and HIM-028-SD were collected in Northeast Cape Fear River near Ness 

Creek, upstream of site. (Ref. 35, pp. 8, 9; Fig. 8). The highest background concentration of each 

contaminant of concern reported in these background samples for each sampling date was used 

for evaluating the release samples (Tables 5, 6, 8, 9 of this HRS documentation record). 
39 

Table 4. Background Sediment Sample Descriptions 

Sample ID Date Time Sample Description References 

HI05cSD 8/3/09 9:50 

Grab sediment sample at mouth of unnamed 

tributary, background sample; some gravel 

mixed with dark to medium gray, loose clay.

Ref. 5, pp. 79, 

80; Fig. 6 

HI40DSD 8/3/09 11:00 

Background sample in Northeast Cape Fear 

River, duplicate of HI40DSD; clay, medium 

to dark brown overlaying dark gray to black 

organic clay.

Ref. 5, pp. 85, 

86; Fig. 6 

HI40SD 8/3/09 11:00 

Background sample in Northeast Cape Fear 

River; clay, medium to dark brown 

overlaying medium to dark black.

Ref. 5, pp. 83, 

84; Fig. 6 

HI41SD 8/3/09 10:30 

Background sample in Northeast Cape Fear, 

adjacent to mouth of unnamed tributary; 

unknown composition.

Ref. 5, pp. 81, 

82; Fig. 6 

HIM-027-SD 4/1/03 12:25 

Background sample in Northeast Cape Fear 

River near Ness Creek, upstream of property; 

silty, organic soil.

Ref. 4, p. 19; 

Ref. 25, pp. 1, 

8; Fig. 8 

HIM-028-SD 4/1/03 12:35 

Background sample in Northeast Cape Fear 

River near Ness Creek, upstream of property; 

dark brown silt.

Ref. 4, p. 19; 

Ref. 25, pp. 1, 

8, 9; Fig. 8 
40 

Table 5. Hazardous Substances in Background Samples - Inorganic 

Sample ID Contaminant Concentration (mg/kg) SQL* References 

Mercury 0.16UJ(0.44U) 1,2 0.44 

Arsenic 9.7 4.1 

Cadmium 2.1U 2.1 

Copper 18 10 

Lead 22 4.1 

Nickel 9.1J(16U) 2 16 

HI05cSD 

Zinc 79 25 

Ref. 5, pp. 239, 265, 

268, 279 

Mercury 0.18UJ(0.44U) 1,2 0.44 

Arsenic 11 4.3 

Cadmium 2.2U 2.2 

Copper 30 11 

Lead 25 4.3 

Nickel 13J(17U) 2 17 

HI40SD 

Zinc 92 26 

Ref. 5, pp. 240, 266, 

268, 340 

Mercury 0.16UJ(0.44U) 1,2 0.44 

Arsenic 11 4.3 

Cadmium 2.1U 2.1 

Copper 18 11 

Lead 25 4.3 

Nickel 11J(17U) 2 17 

HI40DSD 

Zinc 93 26 

Ref. 5, pp. 240, 266, 

268, 339 

Mercury 0.14UJ(0.43U) 1,2 0.43 

Arsenic 11 4.2 

Cadmium 2.1U 2.1 

Copper 19 11 

Lead 32 4.2 

Nickel 11J(17U) 2 17 

HI41SD 

Zinc 96 25 

Ref. 5, pp. 240, 266, 

268, 341 

HIM-027-SD Cadmium 0.50U 0.50 Ref. 4, pp. 87, 284 

HIM-028-SD Cadmium 0.25U 0.25 Ref. 4, pp. 89, 284 

* SQLs are the sample-specific quantitation limits as reported as the MRLs (Minimum 

Reporting Limits) on the analytical data sheets. Each SQL corresponds to the lowest 

demonstrated level of acceptable quantitation and is adjusted for the amount of sample 

prepared, dilution performed, and percent moisture in the source samples (Ref. 5, p. 268). 

U – The analyte was not detected at or above the reporting limit (Ref. 4, p. 87; Ref. 5, 

268). 

J – The identification of the analyte is acceptable; the reported value is an estimate (Ref. 5, 

p. 268). 

1 – Concentration reported is less than the lowest standard on calibration curve. 

2 – Result is greater than Method Detection Limit (MDL) but less than MRL. The number 
41 

in ( ) is the SQL. 

Bolded values represent the highest levels of detectable contaminants in background 

sediment samples. 
42 

Table 6. Hazardous Substances in Background Samples – Organic 

Sample ID Contaminant Concentration (ug/kg) SQL* References 

Fluoranthene 97J(850U) 1 850 

Pyrene 130J(850U) 1 850 

PCB-1254 160U 160 

HI05cSD 

PCB-1260 160U 160 

Ref. 5, pp. 247, 526, 

529, 552, 553, 761, 772 

Fluoranthene 150J(730U) 1 730 

Pyrene 150J(730U) 1 730 

PCB-1254 140U 140 

HI40SD 

PCB-1260 140U 140 

Ref. 5, pp. 248, 254, 

527, 529, 732, 733, 762, 

832 

Fluoranthene 200J(670U) 1 670 

Pyrene 190J(670U) 1 670 

PCB-1254 130U 130 

HI40DSD 

PCB-1260 130U 130 

Ref. 5, pp. 248, 254, 

527, 529, 729, 730, 762, 

831 

Fluoranthene 200J(740U) 1 740 

Pyrene 340J(740U) 1 740 

PCB-1254 140U 140 

HI41SD 

PCB-1260 140U 140 

Ref. 5, pp. 248, 527, 

529, 735, 736, 762, 833 

* SQLs are the sample-specific quantitation limits as reported as the MRLs (Minimum 

Reporting Limits) on the analytical data sheets. Each SQL corresponds to the lowest 

demonstrated level of acceptable quantitation and is adjusted for the amount of sample 

prepared, dilution performed, and percent moisture in the sediment samples (Ref. 5, p. 

529). 

U – The analyte was not detected at or above the reporting limit (Ref. 5, p. 529). 

J – The identification of the analyte is acceptable; the reported value is an estimate (Ref. 5, 

p. 529). 

1 – Concentration reported is less than the lowest standard on calibration curve. 

Contaminated Samples - Sediment

From the August 2009 sampling event, samples HI17cSD, HI18SD, and HI19SD 

document observed releases of site contaminants inside the northern slip. Arsenic and lead are 

present at elevated levels in all three of these samples, while all contaminants of concern used for 

scoring the site (arsenic, cadmium, copper, lead, mercury, nickel, zinc, fluoranthene, pyrene, and 

PCBs) in this HRS documentation record are present at elevated levels at the PPE in the northern 

slip (HI17cSD). HI28bSD, HI28SD, HI29SD, and HI30SD document observed releases of at 

least one source-related contaminant inside the southern slip. Lead is present at elevated levels in 

all four of these samples. Fluoranthene and pyrene are present at elevated levels in three of these 

samples (Tables 7, 8, 9; Fig. 6). All source-related contaminants of concern except mercury are 

present at elevated levels at the PPE in the southern slip. Observed releases of fluoranthene and 

pyrene are also present along the main river channel, just south of the southern slip (HI36SD) 

(Tables 7, 9; Fig. 6). 

April 2003 samples HIM-022-SD and HIM-024-SD were collected at the mouths of each 

of the slips, at the river channel. Cadmium was present at elevated levels in both of these samples 

(Tables, 7, 8; Fig. 7).
43 

Table 7. Sediment Release Sample Descriptions 

Sample ID Date Time Sample Description References 

HI17cSD 8/4/09 13:40 

Grab sediment sample at northwest corner of 

northern slip, PPE; black organic clay mixed with 

vegetative material.

Ref. 5, pp. 109, 

110; Fig. 6 

HI18SD 8/4/09 14:15 Grab sediment sample along northern slip, just 

west of barges; unknown composition.

Ref. 5, pp. 111, 

112; Fig. 6 

HI19SD 8/4/09 9:40 

Grab sediment sample along northern slip, 

adjacent to barge; medium brown sand overlaid 

by black organic clay.

Ref. 5, pp. 99, 

100; Fig. 6 

HI20bSD 8/4/09 10:00 Grab sediment sample along northern slip; 

unknown composition.

Ref. 5, pp. 87, 

88; Fig. 6 

HI28bSD 8/4/09 8:15 

Grab sediment sample at northwest corner of 

southern slip, PPE; brown sands with slight oily 

sheen mixed with black organic clay; bottom of 

sample was lighter brown sand mixed with some 

gravel.

Ref. 5, pp. 93, 

94; Fig. 6 

HI28SD 8/4/09 8:35 

Grab sediment sample along southern slip; fine to 

medium black sand with some sheen and mixed 

with wood over dark brown medium sand.

Ref. 5, pp. 95, 

96; Fig. 6 

HI29SD 8/4/09 9:00 Grab sediment sample along southern slip; 

unknown composition.

Ref. 5, pp. 97, 

98; Fig. 6 

HI30SD 8/4/09 11:05 

Grab sediment sample along southern slip, 

adjacent to barge; fine to medium brown sand 

mixed with some black clay.

Ref. 5, pp. 101, 

102; Fig. 6 

HI31aSD 8/4/09 12:05 Grab sediment sample near mouth of southern 

slip; black organic clay mixed with fine sand.

Ref. 5, pp. 107, 

108; Fig. 6 

HI36SD 8/4/09 11:20 

Grab sediment sample in Northeast Cape Fear 

River, south of southern slip; medium to coarse 

brown sand mixed with some reddish gravel and 

reddish sand.

Ref. 5, pp. 103, 

104; Fig. 6 

HI37SD 8/3/09 14:00 

Grab sediment sample in Northeast Cape Fear 

River between the two slips; brown sand mixed 

with gravel and live mussels.

Ref. 5, pp. 91, 

92; Fig. 6 

HI38SD 8/4/09 11:45 

Grab sediment sample near mouth of northern 

slip; black organic clay over brown silty very fine 

sand.

Ref. 5, pp. 105, 

106; Fig. 6 

HI39SD 8/3/09 12:10 

Grab sediment sample in Northeast Cape Fear 

River near mouth of northern slip; unknown 

composition.

Ref. 5, pp. 89, 

90; Fig. 6 

HIM-022-SD 4/1/03 11:32 

Grab sediment sample in Northeast Cape Fear 

River at mouth of northern slip; black, slimy, 

jello-like substance.

Ref. 25, pp. 1, 6, 

7; Fig. 7 

HIM-024-SD 4/1/03 11:15 

Grab sediment sample in Northeast Cape Fear 

River at mouth of southern slip; very black and 

slimy with consistency similar to jello.

Ref. 25, pp. 1, 6; 

Fig. 7 
44 

Table 8. Hazardous Substances in Sediment Release Samples - Inorganic 

Sample ID Contaminant Concentration 

(mg/kg) SQL* References 

Mercury 1.3 0.46 

Arsenic 170 4.5 

Cadmium 5.4 2.2 

Copper 440 11 

Lead 780 4.5 

Nickel 28 18 

HI17cSD 

Zinc 1,200 27 

Ref. 5, pp. 244, 265, 301 

Arsenic 56 4.4 

HI18SD Lead 220 4.4 

Zinc 380 26 

Ref. 5, pp. 244, 266, 268, 305 

Arsenic 47 3.4 

HI19SD Copper 94 8.6 

Lead 200 3.4 

Ref. 5, pp. 243, 266, 268, 307 

Arsenic 360 1.4 

Cadmium 4.9 0.7 

Copper 180 3.5 

Lead 610 1.4 

Nickel 36 5.6 

HI28bSD 

Zinc 970 8.4 

Ref. 5, pp. 242, 266, 322 

Mercury 0.17 0.14 

Arsenic 38 1.4 

Cadmium 0.94 0.7 

HI28SD 

Lead 580 1.4 

Ref. 5, pp. 242, 266, 321 

Lead 470 2.1 HI29SD 

Zinc 560 13 Ref. 5, pp. 242, 266, 268, 323 

HI30SD Lead 120 2.2 Ref. 5, pp. 243, 266, 268, 324 

HIM-022-SD Cadmium 0.55 0.5 Ref. 4, pp. 78, 80, 87, 283 

HIM-024-SD Cadmium 0.67 0.5 Ref. 4, pp. 80, 82, 87, 283 

* SQLs are the sample-specific quantitation limits as reported as the MRLs (Minimum 

Reporting Limits) on the analytical data sheets. Each SQL corresponds to the lowest 

demonstrated level of acceptable quantitation and is adjusted for the amount of sample 

prepared, dilution performed, and percent moisture in the sediment samples (Ref. 5, p. 

268). 
45 

Table 9. Hazardous Substances Found in Sediment Release Samples - Organic 

Sample ID Contaminant Concentration 

(ug/kg) SQL* References 

Fluoranthene 5,900J(5,900) 1 440 

Pyrene 4,900J(4,900) 1 440 

PCB-1254 230 140 

HI17cSD 

PCB-1260 160 140 

Ref. 5, pp. 253, 526, 529, 

618, 619, 761, 794; Ref. 8, 

p. 8 

HI19SD PCB-1260 610 100 Ref. 5, pp. 251, 762, 800 

Fluoranthene 720 250 

Pyrene 1,200 250 

PCB-1254 340 47 

HI28bSD 

PCB-1260 85 47 

Ref. 5, pp. 251, 527, 681, 

682, 762, 815 

Fluoranthene 930 220 

HI28SD Pyrene 790 220 

PCB-1254 45 43 

Ref. 5, pp. 251, 527, 678, 

679, 762, 814 

Fluoranthene 2,400 730 HI29SD 

Pyrene 2,100 730 

Ref. 5, pp. 251, 527, 684, 

685 

Fluoranthene 770 210 HI36SD 

Pyrene 740 210 

Ref. 5, pp. 252, 527, 720, 

721 

* SQLs are the sample-specific quantitation limits as reported as the MRLs (Minimum 

Reporting Limits) on the analytical data sheets. Each SQL corresponds to the lowest 

demonstrated level of acceptable quantitation and is adjusted for the amount of sample 

prepared, dilution performed, and percent moisture in the source samples (Ref. 5, p. 529). 

J – The identification of the analyte is acceptable; the reported value is an estimate. 

1 – Surrogate recovery is lower than established control limits; therefore, result is biasedlow (Ref. 5, pp. 529, 618, 619). Low biased results for release samples do not require 

adjustment (Ref. 8, p. 8). 

 Further Discussion

 The April 2003 ESI sampling event, conducted by NC Superfund personnel, included 

sediment sampling at the PPE in each slip, the mouths of each slip, and upstream and downstream 

along the main river channel. Cadmium, copper, lead, and zinc were detected at levels over 

background at the PPEs into both slips. Arsenic was detected at an elevated level at the PPE in 

the northern slip, while nickel was detected at an elevated level at the PPE in the southern slip. 

Cadmium was detected at elevated levels at the mouths of both slips. Fluoranthene and pyrene 

were detected at elevated levels along the main river channel, south of the southern slip (Ref. 4, 

pp. 13, 20, 25, 26, 29-31). 
46 

4.1.2.1.1.1 Attribution from Source to Surface Water 

From the early 1900’s up until the 1950’s, the property was used for fertilizer operations 

(Ref. 12, pp. 8, 9, 13, 14; Ref. 13, pp. 1, 2). Typically, sulfuric acid was manufactured by 

roasting pyrites to drive off the sulfur in gaseous form, which was reacted with water in the lead 

chambers to form the acid. Where pyrite ore is roasted, there will be a residue (cinders) which 

may contain a wide range of heavy metals. During this time period, acid chambers were typically 

lined with lead. Lead-bearing spent acid released from the chambers after treatment of the 

phosphate rock typically resulted in lead-contaminated, low-pH soils. Some contaminants 

associated with fertilizer operations during this time period include arsenic, cadmium, copper, 

lead, mercury, vanadium, zinc, platinum, and asbestos (Ref. 14, pp. 1-54; Ref. 27, pp. 1, 2).

During the 1960’s and 1970s, Horton Industries conducted ship breaking of WWII Liberty 

ships in the two slips located on the property (Ref. 12, p. 1; Ref. 16, p. 1; Ref. 17, pp. 1, 3). 

Typical contaminants associated with ship-breaking include asbestos, PCBs, PAHs, barium, 

cadmium, chromium, copper, lead, nickel, and zinc (Ref. 28, pp. 22, 47, 65, 83, 114, 150, 170, 

171). 

The NC Superfund Section conducted an ESI sampling event at the site on April 1-2, 

2003. Eight three-point composite surface soil samples were collected from the area of the former 

acid chamber and the area of the former ship-breaking operations, including drainage paths to 

each of the slips, to determine the presence or absence of contaminated soils (Ref. 25, pp. 1-27). 

Soil sample results indicated elevated levels of metals (including arsenic, cadmium, copper, lead, 

mercury, nickel, and zinc), PAHs, pesticides, polychlorinated biphenyls (PCBs), and asbestos, as 

compared to background samples collected from an area expected to be unimpacted by facility 

operations (Ref. 4, pp. 12-17). 

In January 2007, the entire eastern portion of the Horton property was gridded off and 

sampled for arsenic, lead, and PCBs (Ref. 26, pp. 1, 2). Grab soil samples from 80 grid locations 

were screened with an XRF unit; concentrations at 37 locations exceeded the EPA industrial 

removal action levels (RALs) for lead (1,200 ppm) and/or arsenic (160 pm) (Ref. 26, pp. 8, 9, 12-

14). Laboratory confirmation samples at ten of these locations detected levels of arsenic as high 

as 82J ppm, lead as high as 2,400 ppm, PCB-1254 as high as 3,800 ppb, and PCB-1262 as high as 

1,900 ppb (Ref. 26, pp. 3, 7, 15, 16). 

During the week of August 3, 2009, personnel from EPA, NC, and OTIE conducted an 

ESI sampling event at the facility (Ref. 5, p. 11). Of the source soil samples collected, 17 surface, 

12 subsurface, and four deep subsurface samples contained at least one operations-related 

contaminant at an elevated level, as compared to background levels. Mercury, cadmium, nickel, 

and zinc were detected at higher elevated levels in surface soil samples, while arsenic, copper, and 

lead were detected at higher elevated levels in subsurface soil samples. In addition, arsenic, 

cadmium, copper, lead, and zinc were all detected at elevated levels in deep subsurface soil 

samples (Ref. 5, pp. 29, 30, 45-48, 55-58). SVOCs, and PCBs, were detected at elevated levels in 

both surface and subsurface soil samples. Fluoranthene, pyrene, PCB-1260, and PCB-1268 were 

detected at higher elevated levels in surface soil samples. PCB-1254, however, was detected at its 

highest elevated levels in the subsurface soil samples (Ref. 5, pp. 35-44, 49-54, 58). 
47 

The source (Source 1) is contaminated soils bounded by surface soil samples documented 

in Tables 1-3 and shown on Figure 3 of this HRS documentation record. Areas comprising this 

bounded portion include the former lead acid chamber area, former ship-breaking operations, and 

areas where dredged materials from the slips was placed during the 1960s (Ref. 12, p. 1; Ref. 13, 

p. 1; Ref. 15, p. 1; Ref. 17, pp. 1, 3). The square footage of the bounded area was determined 

using Geographic Information System (GIS) software, selecting the Calculate Geometry function 

(see Figure 3 of this HRS documentation record). 

Source 1 drains towards the two slips protruding inland from the Northeast Cape Fear 

River. Flow from the source enters the western edges of the slips at the probable points of entry 

(PPEs) (Ref. 23, p. 1; Fig. 6). Arsenic and lead are present at elevated levels in three of the 

samples collected from inside the northern slip, while all contaminants of concern used for 

scoring the source (arsenic, cadmium, copper, lead, mercury, nickel, zinc, fluoranthene, pyrene, 

and PCBs) in this HRS documentation record are present at elevated levels at the PPE in the 

northern slip. Lead is present at elevated levels in all four of the samples collected from inside 

the southern slip. Fluoranthene and pyrene are present at elevated levels in three of these samples 

(Tables 7, 8, 9; Fig. 6). Observed releases of fluoranthene and pyrene are also present along the 

main river channel, just south of the southern slip (HI36SD) (Tables 7, 9; Fig. 6). 

There are three current/former facilities that are adjacent to this site – Northeast Chemical, 

V.C. Almont, and Sigma Recycling (Fig. 2). The Northeast Chemical and V.C. Almont sites, 

located to the north of the Horton property, are former phosphate fertilizer manufacturers. Lead 

and arsenic are the contaminants most associated with these two sites (Ref. 18, pp. 4-8, 45-48, 52-

54, 65; Ref. 31, p. 1, 2). The Sigma Recycling site, located south of the Horton property, is a 

former ship-breaking operation. While Sigma Recycling contained some lead and PCBs, the 

primary contaminants of concern were petroleum and arsenic. Remediation at Sigma is complete 

(Ref. 32, pp. 1, 58-61, 201, 202).

Sediment samples were collected from the main river channel immediately upstream and 

downstream of Horton during both the April 2003 and August 2009 ESI sampling events. Similar 

contaminants associated with the adjacent properties and their former operations were not 

detected at elevated levels in the upstream samples (Ref. 4. pp. 24, 25, 26, 29-31; Ref. 5, pp. 26, 

61-64, 66, 67; Fig. 6). Fluoranthene and pyrene, detected at elevated levels in the downstream 

sample (HI36SD), were also present at elevated levels in the source as well as in the sediment 

samples collected inside the southern slip (Ref. 5, pp. 26, 59-62; Tables 7, 9; Fig. 6). 
48 

Table 10. Attribution – Contaminant Correlation 

Contaminants 

Associated with 

Fertilizer Operations 

Contaminants 

Associated with ShipBreaking Operations Source Contaminants 

Observed Release to 

SW Pathway 

Contaminants 

arsenic, cadmium, 

copper, lead, 

mercury, vanadium, 

zinc, platinum, and 

asbestos 

asbestos, PCBs, 

PAHs, barium, 

cadmium, chromium, 

copper, lead, nickel, 

and zinc 

arsenic, cadmium, 

copper, lead, 

mercury, nickel, zinc, 

fluoranthene, pyrene, 

PCB-1254, PCB1260, PCB-1268 

arsenic, cadmium, 

copper, lead, 

mercury, nickel, 

zinc, fluoranthene, 

pyrene, PCB-1254, 

PCB-1260 

(Ref. 14, pp. 1, 2, 6, 

12, 20, 22, 29, 37, 

42-44; Ref. 27, pp. 1, 

2) 

(Ref. 28, pp. 22, 47, 

65, 83, 114, 150, 170, 

171) 

Tables 1, 2, and 3 of 

this HRS 

Documentation 

Record 

Tables 7, 8, and 9 of 

this HRS 

Documentation 

Record 

================================================================== 

Hazardous Substances Released: 

Arsenic, Cadmium, Copper, Lead, Mercury, Nickel, Zinc, Fluoranthene, Pyrene, PCB-1254, 

PCB-1260 

Surface Water Pathway Observed Release Factor Value = 550
49 

4.1.2.1.2 Potential to Release

4.1.2.1.2.1 Potential to Release by Overland Flow

Potential to release was not evaluated because an observed release to surface water was 

established by chemical analysis (see Section 4.1.2.1.1 of this HRS documentation record). 
50 

4.1.3 Human Food Chain Threat

 The human food chain threat is evaluated based on three factor categories: likelihood of 

release, waste characteristics, and targets. 

4.1.3.2 Human Food Chain Threat – Waste Characteristics

4.1.3.2.1 Toxicity/Persistence/Bioaccumulation

 An observed release to a fishery has been documented (Ref. 33, pp. 1, 2). The Northeast 

Cape Fear River and the Cape Fear River in the vicinity of the Horton facility are both salt water 

bodies (Ref. 29, pp. 23-25, 34, 35, 38). The HRS instructs that if bioconcentration factor (BCF) 

data are available for both fresh water and salt water for the hazardous substance, use the BCF 

data that corresponds to the type of water body (that is, fresh water or salt water) in which the 

fisheries are located to assign the bioaccumulation potential factor value to the hazardous 

substance. Because the entire surface water pathway is considered salt, only salt water 

Bioaccumulation Potential Factor Value (BPFV) values are used (Ref. 1, Section 4.1.3.2.1.3). 

Table 11. Source 1 Contaminants Documented in Observed Release 

 to Sediment in a Fishery 

Hazardous 

Substance 

Toxicity 

Factor 

Value 

PF# 

BPFV* 

Salt 

Food Chain 

T/P Value 

(Ref. 1, 

Table 4-12)

T/P/BPFV 

(Ref. 1, Table 

4-16) 

Arsenic 10,000 1 500 10,000 5 x 106

Cadmium 10,000 1 50,000 10,000 5 x 108

Copper 0 1 50,000 0 0 

Lead 10,000 1 5,000 10,000 5 x 107

Mercury 10,000 1 50,000 10,000 5 x 108

Nickel 10,000 1 500 10,000 5 x 106

Zinc 10 1 50,000 10 5 x 105

Fluoranthene** 100 1 5,000 100 5 x 105

Pyrene 100 1 5,000 100 5 x 105

PCBs 10,000 1 50,000 10,000 5 x 108

T/P/BPFV = Toxicity/Persistence/Bioaccumulation Potential Factor Values (Ref. 1, Table 4-16). 

T/p = Toxicity/Persistence Factor Values (Ref. 1, Table 4-12; Ref. 2, pp. 2-8). 

BPFV = Bioaccumulation Potential Factor Values, Ref. 2, pp. 2-8. 

#

PF = Persistence Factor Value for Rivers (Ref. 1, section 4.1.3.2.1.2; Ref. 2, pp. 2-8). 

*Ref. 1, Table 4 - 15, Section 4.1.3.2.1.3; Ref. 2, pp. 2-8. 

**Benzo(j,k)fluorene (Ref. 2, p. 3) 

===================================================================== 

Toxicity/Persistence/Bioaccumulation Factor Value = 5 x 108
51 

4.1.3.2.2 Hazardous Waste Quantity

HRS (Ref. 1) Section 4.1.3.2.2 instructs that if any target for that migration pathway is 

subject to Level I or Level II concentrations, and if hazardous constituent quantity is not 

adequately documented, assign either the value from Table 2-6 or a value of 100, whichever is 

greater, as the hazardous waste quantity factor value for that pathway (Ref. 1, Section 2.4.2.2). A 

Level II fishery has been documented, as shown in Section 4.1.3.3.2.2 of this HRS documentation 

record. 

Hazardous Waste Quantity Factor Value = 100

4.1.3.2.3 Human Food Chain Threat Waste Characteristics Factor Category Value

Toxicity/Persistence Value = 10,000 

Bioaccumulation Potential Factor Value = 50,000 

Toxicity/Persistence Value x Hazardous Waste Quantity Factor Value: 

 10,000 x 100 = 1,000,000 (1 x 106

) 

(Toxicity/Persistence x Hazardous Waste Quantity) x Bioaccumulation Potential 

Value: (1 x 106 ) x 50,000 = 5 x 1010

===================================================================== 

Human Food Chain Hazardous Waste Quantity Assigned Value/Human Food Chain Waste 

Characteristics Factor Category Value = 320

(Ref. 1, Table 2 – 7, Sections 4.1.3.2.3 and 2.4.3.2) 
52 

4.1.3.3 Human Food Chain Threat - Targets

Actual Human Food Chain Contamination 

A hazardous substance having a bioaccumulation potential factor value of 500 or greater is 

present in a sediment sample in the watershed at a level that meets the criteria for an observed 

release, and a portion of the fishery is within the boundaries of the observed release. An observed 

release to surface water was documented in Section 4.1.2.1.1. An observed release to a fishery 

has been documented (Ref. 33, pp. 1, 2). 

4.1.3.3.1 Food Chain individual 

A Level II fishery has been documented, as shown in Section 4.1.3.3.2.2 of this HRS 

documentation record. 

===================================================================== 

Food Chain Individual Factor Value = 45 

4.1.3.3.2 Population 

4.1.3.3.2.1 Level I Concentrations – not scored 

4.1.3.3.2.2 Level II Concentrations

 Arsenic, cadmium, copper, lead, mercury, nickel, zinc, fluoranthene, pyrene, PCB-1254, 

and PCB-1260 have been documented in source 1 and in sediment in the fishery. The level of 

contaminants in the fishery is summarized below (see also Tables 7 and 8 of this HRS 

documentation record): 

Sample ID Contaminant Concentration 

(mg/kg) 

Mercury 1.3 

Arsenic 170 

Cadmium 5.4 

Copper 440 

Lead 780 

Nickel 28 

Zinc 1,200 

Fluoranthene 5,900J(5,900)

Pyrene 4,900J(4,900)

PCB-1254 230 

HI17cSD 

PCB-1260 160 
53 

Sample ID Contaminant Concentration 

(mg/kg) 

Arsenic 56 

HI18SD Lead 220 

Zinc 380 

Arsenic 47 

Copper 94 

Lead 200 

HI19SD 

PCB-1260 610 

Arsenic 360 

Cadmium 4.9 

Copper 180 

Lead 610 

Nickel 36 

Zinc 970 

Fluoranthene 720 

Pyrene 1,200 

PCB-1254 340 

HI28bSD 

PCB-1260 85 

Mercury 0.17 

Arsenic 38 

Cadmium 0.94 

Lead 580 

Fluoranthene 930 

Pyrene 790 

HI28SD 

PCB-1254 45 

Lead 470 

Zinc 560 

Fluoranthene 2,400 

HI29SD 

Pyrene 2,100 

HI30SD Lead 120 

Fluoranthene 770 HI36SD 

Pyrene 740 

HIM022SD Cadmium 0.55 

HIM024SD Cadmium 0.67 

Active fishing in the Northeast Cape Fear River has been documented, and, although the 

annual human food chain production is unknown, greater than zero pounds of fish are caught in 

the Northeast Cape Fear River and consumed (Ref. 33, pp. 1, 2). A Food Chain Population value 

of 0.03 is assigned (Ref. 1, Table 4-18). 

Level II Concentration Factor Value = 0.03
54 

4.1.3.3.2.1 Potential Human Food Chain Contamination -- not evaluated

 

4.1.3.3.3 Calculation of Human Food chain threat - targets factor category value 

(Ref. 1, Section 4.1.3.3.3) 

Human food chain threat-targets factor category value = 

45 + .03 = 45.03 

(Ref. 1, Section 4.1.3.3.1 and Table 4-18) 

4.1.3.4 Calculation of human food chain threat score 

Likelihood of release x waste characteristics x targets / 82,500 = 

550 x 320 x 45.03 / 82,500 = 96.06

(Ref. 1, Section 4.1.3.4) 

==================================================================== 

Human Food Chain Threat Score = 96.06
55 

Table 4-1 Surface Water Overland/Flood Migration Component Scoresheet

Human Food Chain Threat

Likelihood of Release: 550

Waste Characteristics: 

Toxicity/Persistence/Bioaccumulation 

 5 x 108

Hazardous Waste Quantity 

 

 100

Waste Characteristics Factor Category Value 320

Targets: 

 Food Chain Individual Factor Value 45.03

 

Human Food Chain Threat Score: 

[550 x 320 x 45.03] / 82,560 = 96.06

 Human Food Chain Threat Score = 96.06