United States 

Environmental Protection 

Agency 

1200 Pennsylvania Avenue, N.W. 

Washington, D.C. 20460 

September 

2011 

Office of Solid Waste and Emergency Response 

Support Document for the 

Revised National Priorities List 

Final Rule – Horton Iron & Metal Co.
Support Document for the 

Revised National Priorities List 

Final Rule 

Horton Iron & Metal Co. 

September 2011 

Site Assessment and Remedy Decisions Branch 

Office of Superfund Remediation and Technology Innovation 

Office of Solid Waste and Emergency Response 

U.S. Environmental Protection Agency 

Washington, DC 20460
Horton Iron & Metal Co. NPL Listing Support Document September 2011 

Table of Contents

Executive Summary.................................................................................................................................... ii

Introduction ............................................................................................................................................... iii

Background of the NPL .......................................................................................................................... iii

Development of the NPL ........................................................................................................................ iii

Hazard Ranking System.......................................................................................................................... iv

Other Mechanisms for Listing ................................................................................................................. v

Organization of this Document................................................................................................................ v

Glossary .................................................................................................................................................. vi

1. List of Commenters and Correspondence ....................................................................................... 1

2. Site Description .................................................................................................................................. 1

3. Summary of Comments..................................................................................................................... 2

3.1 Extent of Site ................................................................................................................................ 2

3.2 Economic Impacts of Listing........................................................................................................ 3

3.3 Delay Listing ................................................................................................................................ 3

3.4 Source Containment ..................................................................................................................... 4

4 Conclusion .......................................................................................................................................... 6

Attachment 1: October 2009 EPA Letter Regarding Voluntary Actions 

 i 
Horton Iron & Metal Co. NPL Listing Support Document September 2011 

Executive Summary 

Section 105(a)(8)(B) of CERCLA, as amended by SARA, requires that the EPA prepare a list of national 

priorities among the known releases or threatened releases of hazardous substances, pollutants or contaminants 

throughout the United States. An original National Priorities List (NPL) was promulgated on September 8, 1983 

(48 FR 40658). CERCLA requires that the EPA update the list at least annually. 

This document provides responses to public comments received on the Horton Iron & Metal Co. site, proposed on 

October 21, 2010 (75 FR 64976). This site is being added to the NPL based on an evaluation under the EPA’s 

Hazard Ranking System (HRS) in a final rule published in the Federal Register in September 2011. 

 ii 
Horton Iron & Metal Co. NPL Listing Support Document September 2011 

Introduction 

This document explains the rationale for adding the Horton Iron & Metal Co. site in Wilmington, North Carolina, 

to the National Priorities List (NPL) of uncontrolled hazardous waste sites and provides responses to public 

comments received on this site listing proposal. The EPA proposed this site to the NPL on October 21, 2010 (75 

FR 64976). This site is being added to the NPL based on an evaluation under the Hazard Ranking System (HRS) 

in a final rule published in the Federal Register in September 2011. 

Background of the NPL 

In 1980, Congress enacted the Comprehensive Environmental Response, Compensation, and Liability Act 

(CERCLA), 42 U.S.C. Sections 9601 et seq. in response to the dangers of uncontrolled hazardous waste sites. 

CERCLA was amended on October 17, 1986, by the Superfund Amendments and Reauthorization Act (SARA), 

Public Law No. 99-499, stat., 1613 et seq. To implement CERCLA, the EPA promulgated the revised National 

Oil and Hazardous Substances Pollution Contingency Plan (NCP), 40 CFR Part 300, on July 16, 1982 (47 FR 

31180), pursuant to CERCLA Section 105 and Executive Order 12316 (46 FR 42237, August 20, 1981). The 

NCP, further revised by the EPA on September 16, 1985 (50 FR 37624) and November 20, 1985 (50 FR 47912), 

sets forth guidelines and procedures needed to respond under CERCLA to releases and threatened releases of 

hazardous substances, pollutants or contaminants. On March 8, 1990 (55 FR 8666), the EPA further revised the 

NCP in response to SARA. 

Section 105(a)(8)(A) of CERCLA, as amended by SARA, requires that the NCP include 

criteria for determining priorities among releases or threatened releases throughout the United 

States for the purpose of taking remedial action and, to the extent practicable, take into account 

the potential urgency of such action, for the purpose of taking removal action. 

Removal action involves cleanup or other actions that are taken in response to emergency conditions or on a 

short-term or temporary basis (CERCLA Section 101). Remedial action is generally long-term in nature and 

involves response actions that are consistent with a permanent remedy for a release (CERCLA Section 101). 

Criteria for placing sites on the NPL, which makes them eligible for remedial actions financed by the Trust Fund 

established under CERCLA, were included in the HRS. The EPA promulgated the HRS as Appendix A of the 

NCP (47 FR 31219, July 16, 1982). On December 14, 1990 (56 FR 51532), the EPA promulgated revisions to the 

HRS in response to SARA, and established the effective date for the HRS revisions as March 15, 1991. 

Section 105(a)(8)(B) of CERCLA, as amended, requires that the statutory criteria provided by the HRS be used to 

prepare a list of national priorities among the known releases or threatened releases of hazardous substances, 

pollutants or contaminants throughout the United States. The list, which is Appendix B of the NCP, is the NPL. 

An original NPL of 406 sites was promulgated on September 8, 1983 (48 FR 40658). At that time, an HRS score 

of 28.5 was established as the cutoff for listing because it yielded an initial NPL of at least 400 sites, as suggested 

by CERCLA. The NPL has been expanded several times since then, most recently on March 10, 2011 (76 FR 

13089). The Agency also has published a number of proposed rulemakings to add sites to the NPL. The most 

recent proposal was on March 10, 2011 (76 FR 13113). 

Development of the NPL 

The primary purpose of the NPL is stated in the legislative history of CERCLA (Report of the Committee on 

Environment and Public Works, Senate Report No. 96-848, 96th Cong., 2d Sess. 60 [1980]). 

 iii 
Horton Iron & Metal Co. NPL Listing Support Document September 2011 

The priority list serves primarily informational purposes, identifying for the States and the public 

those facilities and sites or other releases which appear to warrant remedial actions. Inclusion of a 

facility or site on the list does not in itself reflect a judgment of the activities of its owner or 

operator, it does not require those persons to undertake any action, nor does it assign liability to 

any person. Subsequent government actions will be necessary in order to do so, and these actions 

will be attended by all appropriate procedural safeguards. 

The NPL, therefore, is primarily an informational and management tool. The identification of a site for the NPL is 

intended primarily to guide the EPA in determining which sites warrant further investigation to assess the nature 

and extent of the human health and environmental risks associated with the site and to determine what CERCLAfinanced remedial action(s), if any, may be appropriate. The NPL also serves to notify the public of sites the EPA 

believes warrant further investigation. Finally, listing a site may, to the extent potentially responsible parties are 

identifiable at the time of listing, serve as notice to such parties that the Agency may initiate CERCLA-financed 

remedial action. 

CERCLA Section 105(a)(8)(B) directs the EPA to list priority sites among the known releases or threatened 

release of hazardous substances, pollutants or contaminants, and Section 105(a)(8)(A) directs the EPA to consider 

certain enumerated and other appropriate factors in doing so. Thus, as a matter of policy, the EPA has the 

discretion not to use CERCLA to respond to certain types of releases. Where other authorities exist, placing sites 

on the NPL for possible remedial action under CERCLA may not be appropriate. Therefore, the EPA has chosen 

not to place certain types of sites on the NPL even though CERCLA does not exclude such action. If, however, 

the Agency later determines that sites not listed as a matter of policy are not being properly responded to, the 

Agency may consider placing them on the NPL. 

Hazard Ranking System 

The HRS is the principle mechanism the EPA uses to place uncontrolled waste sites on the NPL. It is a 

numerically based screening system that uses information from initial, limited investigations -- the preliminary 

assessment and site inspection -- to assess the relative potential of sites to pose a threat to human health or the 

environment. HRS scores, however, do not determine the sequence in which the EPA funds remedial response 

actions, because the information collected to develop HRS scores is not sufficient in itself to determine either the 

extent of contamination or the appropriate response for a particular site. Moreover, the sites with the highest 

scores do not necessarily come to the Agency's attention first, so that addressing sites strictly on the basis of 

ranking would in some cases require stopping work at sites where it was already underway. Thus, the EPA relies 

on further, more detailed studies in the remedial investigation/feasibility study that typically follows listing. 

The HRS uses a structured value analysis approach to scoring sites. This approach assigns numerical values to 

factors that relate to or indicate risk, based on conditions at the site. The factors are grouped into three categories. 

Each category has a maximum value. The categories are: 

• likelihood that a site has released or has the potential to release hazardous substances into the 

environment; 

• characteristics of the waste (toxicity and waste quantity); and 

• people or sensitive environments (targets) affected by the release. 

Under the HRS, four pathways can be scored for one or more threats as identified below: 

• Ground Water Migration (Sgw) 

- drinking water 

 iv 
Horton Iron & Metal Co. NPL Listing Support Document September 2011 

• Surface Water Migration (Ssw) 

The following threats are evaluated for two separate migration components, overland/flood migration and 

ground water to surface water. 

- drinking water 

- human food chain 

- sensitive environments 

• Soil Exposure (Ss) 

- resident population 

- nearby population 

- sensitive environments 

• Air Migration (Sa) 

- population 

- sensitive environments 

After scores are calculated for one or more pathways according to prescribed guidelines, they are combined using 

the following root-mean-square equation to determine the overall site score (S), which ranges from 0 to 100: 

4

S + S + S + S = S

2

a

2

s

2

sw

2

gw

If all pathway scores are low, the HRS score is low. However, the HRS score can be relatively high even if only 

one pathway score is high. This is an important requirement for HRS scoring because some extremely dangerous 

sites pose threats through only one pathway. For example, buried leaking drums of hazardous substances can 

contaminate drinking water wells, but -- if the drums are buried deep enough and the substances not very volatile 

-- not surface water or air. 

Other Mechanisms for Listing 

There are two mechanisms other than the HRS by which sites can be placed on the NPL. The first of these 

mechanisms, authorized by the NCP at 40 CFR 300.425(c)(2), allows each State and Territory to designate one 

site as its highest priority regardless of score. The last mechanism, authorized by the NCP at 40 CFR 

300.425(c)(3), allows listing a site if it meets the following three requirements: 

• Agency for Toxic Substances and Disease Registry (ATSDR) of the U.S. Public Health Service has 

issued a health advisory that recommends dissociation of individuals from the release; 

• the EPA determines the site poses a significant threat to public health; and 

• the EPA anticipates it will be more cost-effective to use its remedial authority than to use its emergency 

removal authority to respond to the site. 

Organization of this Document 

The following section contains the EPA responses to site-specific public comments received on the proposal of 

the Horton Iron & Metal Co. site on October 21, 2010 (75 FR 64976). The site discussion begins with a list of 

commenters, followed by a site description, a summary of comments and Agency responses to each comment. A 

concluding statement indicates the effect of the comments on the HRS score for the site. 

 v 
Horton Iron & Metal Co. NPL Listing Support Document September 2011 

 vi 

Glossary 

The following acronyms and abbreviations are used throughout the text: 

Agency U.S. Environmental Protection Agency 

ATSDR Agency for Toxic Substances and Disease Registry 

CERCLA Comprehensive Environmental Response, Compensation, and Liability Act of 1980, 42 

U.S.C. Sections 9601 et seq., also known as Superfund 

CFR Code of Federal Regulations 

EPA U.S. Environmental Protection Agency 

ESI Expanded Site Investigation 

FR Federal Register 

HRS Hazard Ranking System, Appendix A of the NCP 

HRS score Overall site score calculated using the Hazard Ranking System; ranges from 0 to 100 

MDL Method detection limit 

NCDENR North Carolina Department of Environment and Natural Resources 

NCP National Oil and Hazardous Substances Pollution Contingency Plan, 40 C.F.R. Part 300 

NPL National Priorities List, Appendix B of the NCP 

PAH Polycyclic aromatic hydrocarbon 

PCB Polychlorinated biphenyl 

PRP Potentially responsible party 

RCRA Resource Conservation and Recovery Act 

RI/FS Remedial investigation and feasibility study 

SARA Superfund Amendments and Reauthorization Act 

START Superfund Technical Assistance and Response Team 

VOC Volatile organic compound
Horton Iron & Metal Co. NPL Listing Support Document September 2011 

1. List of Commenters and Correspondence 

EPA-HQ-SFUND-2010-0641-0004 Correspondence, dated May 26, 2010, from Dee Freeman, 

Secretary, North Carolina Department of Environment and 

Natural Resources, letter supporting placement of the Horton 

Iron & Metal Co. site on the National Priorities List (NPL) 

EPA-HQ-SFUND-2010-0641-0005 Comment, dated December 23, 2010, from Ramona Cunningham 

O'Bryant, Smith Moore Leatherwood LLP on behalf of Horton 

Iron & Metal Company, Public Commenters 

2. Site Description 

The Horton Iron & Metal Co. site (hereafter referred to as the Site) is the result of the release of hazardous 

substances from the Horton Iron and Metal Company and predecessors who owned and operated facilities at the 

same location. The Site is located along the west bank of the Northeast Cape Fear River in Wilmington, New 

Hanover County, North Carolina. The Site as scored in the HRS documentation record at proposal includes areas 

of contaminated soils located east of the railroad tracks on the Horton Iron & Metal Co. property—identified as 

Source 1—and the associated releases from the Site into Northeast Cape Fear River sediments. The Northeast 

Cape Fear River has been identified as a human food chain fishery. 

The property was owned by the American Agricultural Chemical Company from 1911 until 1949 and by Naco 

Fertilizer Company from 1949 through 1954. Fertilizer operations carried out by American Agricultural Chemical 

Company began on the property by 1915. During the time of fertilizer operations at the facility, acid chambers 

used in the fertilizer operations were typically lined with lead. 

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. In the 1960s, the Horton Iron and Metal Company 

dredged out the boat slips and dredged material was placed on the property, along the northern, western and 

southern edges of the slips. During the 1960s and 1970s, Horton Industries conducted ship breaking of WWII 

Liberty ships in the two slips located on the property. 

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 later an underground storage tank (UST) removal was conducted in 1996. 

Based on the North Carolina Department of Environment and Natural Resources (NCDENR) Division of Waste 

Management Superfund Section recommendation, the Site was added to CERCLIS on July 11, 2002. 

An expanded site investigation (ESI) conducted in 2003 found elevated levels (as compared to background levels) 

of metals, polycyclic aromatic hydrocarbons (PAHs), pesticides and polychlorinated biphenyls (PCBs) in soils at 

the Site. Ground water, surface water and sediment samples also contained elevated levels of several metals 

including arsenic, cadmium, copper, lead, nickel and zinc (as well as some pesticides in one ground water 

sample). 

The areas of contaminated soil were further delineated during a 2007 removal assessment conducted by Tetra 

Tech, the Superfund Technical Assistance & Response Team (START) contractor for the EPA. 

A 2009 ESI detected PCBs, PAHs, volatile organic compounds (VOCs), lead, arsenic, cadmium and mercury in 

surface and subsurface soil samples. Deep subsurface soil samples (8 to 12 feet below ground surface) contained 

 1 
Horton Iron & Metal Co. NPL Listing Support Document September 2011 

metals, including lead and arsenic. Sediment samples collected from the two slips contained elevated levels of 

PCBs, PAHs, mercury, arsenic and lead. Ground water samples contained arsenic, cadmium and lead in the 

ground water beneath the property. Based on the data gathered during the ESI, including the release of 

contaminants to the slips along the Northeast Cape Fear River, a human food chain fishery, the Site was 

recommended for further evaluation and possible inclusion on the National Priorities List (NPL). 

3. Summary of Comments 

Comments were submitted in opposition to listing the Horton Iron & Metal Co. site on the NPL by Smith Moore 

Leatherwood LLP on behalf of the Horton Iron & Metal Company (Horton). Horton commented on the extent of 

the Site and the effects that the site definition and the NPL listing may have on property values. Horton also 

requested that the EPA delay listing to allow potentially responsible parties (PRPs) and the EPA to explore 

measures to address risks posed by the Site. Horton additionally commented that the HRS documentation record 

at proposal did not appropriately consider the existence of a silt fence in its evaluation of source containment at 

the Site. 

3.1 Extent of Site 

Comment: Smith Moore Leatherwood LLP, on behalf of the Horton Iron & Metal Company (hereafter referred to 

as Horton) commented that “EPA has identified the entire facility operated by Horton as the property proposed to 

be placed on the NPL.” Horton continued to quote the HRS documentation record as stating that “[f]or 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.” Horton requested that the EPA restrict the definition of the Site to 

the source area identified in Figure 3 of the HRS documentation record at proposal. This area included the former 

fertilizer manufacturing operations, the boat-breaking operations and the areas where dredge spoil was placed on 

the property. 

Response: The HRS documentation record at proposal did not define the extent of the NPL site as the facility or 

its present property boundaries. As quoted by the commenter, HRS (Section 1.1, Definitions) defines a site as 

“[a]rea(s) where a hazardous substance has been deposited, stored, disposed, or placed, or has otherwise come to 

be located. Such areas may include multiple sources and may include the area between sources.” 

Thus, the Site was appropriately delineated in the HRS evaluation as the contaminated soil source and associated 

releases of contamination. 

Additionally, placing a site on the NPL is based on an evaluation, in accordance with the HRS, of a release or 

threatened release of hazardous substances, pollutants or contaminants. However, the fact that the EPA initially 

identifies and lists the release based on a review of contamination at a certain parcel of property does not 

necessarily mean that the site boundaries are limited to that parcel. 

CERCLA Section 105(a)(8)(A) requires the EPA to list national priorities among the known “releases or 

threatened releases” of hazardous substances; thus, the focus is on the release, not precisely delineated boundaries. 

Further, CERCLA Section 101(a) defines a “facility” as the “site” where a hazardous substance has been 

“deposited, stored, placed, or otherwise come to be located.” The “come to be located” language gives the EPA 

broad authority to clean up contamination when it has spread from the original source. On March 31, 1989 (54 FR 

13298), the EPA stated: 

HRS scoring and the subsequent listing of a release merely represent the initial [emphasis added] 

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 

 2 
Horton Iron & Metal Co. NPL Listing Support Document September 2011 

need to be refined and improved as more information is developed as to where the contamination 

has come to be located; this refining step generally comes during the RI/FS stage. 

The revised HRS (55 FR 51587, December 14, 1990) elaborates on the “come to be located” language, defining 

“site” as “area(s) where a hazardous substance has been deposited, stored, disposed, or placed, or has otherwise 

come to be located. Such areas may include multiple sources and may include the area between the sources.” 

Until the site investigation process has been completed and a remedial action (if any) selected, the EPA can 

neither estimate the extent of contamination at the site, nor describe the ultimate dimensions of the NPL site. Even 

during a remedial action (e.g., the removal of buried waste) the EPA may find that the contamination has spread 

further than previously estimated and the site definition may be correspondingly expanded. In addition, if another, 

unrelated area of contamination is discovered elsewhere on the property, the EPA may decide to evaluate that 

release for the NPL. 

This comment results in no change to the HRS score and no change in the decision to place the Site on the NPL. 

3.2 Economic Impacts of Listing 

Comment: Horton commented that “placing a property on the NPL has enormously negative consequences for 

the owner and operator,” and that “[s]uch a listing destroys property values and makes future use of any portion of 

the property, even the unaffected portions, more cumbersome and subject to regulatory review.” 

Response: Any negative impacts noted by Horton would be engendered by the contamination in the area, not by 

placing the site on the NPL. To the contrary, listing will result in positive economic impacts when the site 

contamination has been addressed. While NPL listing certainly provides additional public information on the site 

contamination, it also provides opportunity for residents, business owners and potential investors to gain detailed 

knowledge and express their concerns and ideas for final solutions in the public forums offered during other 

phases of the Superfund process. 

Both costs and benefits can be associated with listing a site on the NPL. Among the benefits associated with NPL 

listing are increased health and environmental protection as a result of increased public awareness of potential 

hazards. Listing sites as national priority targets also may give States increased support for funding responses at 

particular sites. As a result of the additional CERCLA remedies, there will be lower human exposure to high-risk 

chemicals and higher quality surface water, ground water, soil and air. Therefore, it is possible that any perceived 

or actual negative fluctuations in property values or development opportunities that may result from 

contamination may be countered by positive fluctuations when a CERCLA investigation and any necessary 

cleanup are completed. 

Furthermore, the EPA has discovered and is publicizing by NPL listing, contamination at this site, and may 

require owners, operators and other PRPs to conduct or pay for cleanup. Costs may be imposed on the PRPs based 

on those remedial actions. However, that does not mitigate against placing eligible sites on the NPL, and is not a 

factor specified by CERCLA to be considered in the decision to list a site on the NPL [see CERCLA § 

105(a)(8)(A)]. 

This comment results in no change to the HRS score and no change in the decision to place the Site on the NPL. 

3.3 Delay Listing 

Comment: Horton stated that, upon inquiry by the EPA, it expressed interest in removal action negotiations. 

Horton commented that after the EPA agreed to meet with PRPs, the EPA “went forward with the scoring without 

informing the companies or giving them an opportunity to address the factors that have caused the Site to receive 

 3 
Horton Iron & Metal Co. NPL Listing Support Document September 2011 

a high hazard ranking score.” Horton asserted that threats at the Site “can be reduced by controls on the property 

and by removal of materials from the boat slips and nearby sediments,” and that the EPA should delay NPL 

listing until it has determined PRP willingness to address the risks presented by the site. 

Response: Placing a site on the NPL is not delayed to allow negotiations regarding response actions to be 

completed. Proceeding with the listing process need not inhibit efforts to determine response actions. If Horton or 

any designated PRP wishes to expedite cleanup efforts, it may continue negotiations with the EPA and undertake 

removal actions under supervision of the EPA and pursuant to appropriate agreements with governmental 

authorities (under enforcement authorities of CERCLA or those of other statutes). Placing a site on the NPL does 

not encumber or preclude PRPs from entering into these agreements. The EPA has entered into many such 

agreements before and after a site’s promulgation to the NPL, and such an alternative is available to others1

. 

Furthermore, North Carolina has supported moving forward with NPL listing at the present time. 

This comment results in no change to the HRS score and no change in the decision to place the Site on the NPL. 

3.4 Source Containment 

Comment: Horton noted that the HRS documentation record at proposal assigned a containment value of 10 to 

Source 1 (contaminated soil). However, Horton asserted that “[t]he HRS Documentation Record does not reflect 

that, at the request of the EPA and in a manner approved by the State and the EPA, Horton installed a silt fence to 

restrict any migration from the former fertilizer manufacturing operations to the river and put up fencing to 

restrict access.” Horton concluded that the HRS documentation record scoring should be revised to reflect this 

“engineered, functioning and well maintained run-off control system.” 

Response: The containment factor of 10 assigned to Source 1 in the HRS documentation record at proposal was 

consistent with the HRS. The presence of a silt fence does not alter this assessment. 

HRS Section 2.2.3, Identify hazardous substances available to a pathway, directs the assignment of containment 

values in general: 

In evaluating each migration pathway, consider the following hazardous substances available to 

migrate from the sources at the site to the pathway: 

. . . 

• Surface water migration—overland/flood component. 

- Hazardous substances that meet the criteria for an observed release to surface 

water in the watershed being evaluated. 

- All hazardous substances associated with a source with a surface water 

containment factor value greater than 0 for the watershed (see sections 

4.1.2.1.2.1.1 and 4.1.2.1.2.2.1). 

HRS Section 4.1.2.1.2.1.1, Containment, directs the assignment of the surface water overland/flood containment 

factor, stating in relevant part: 

Determine the containment factor value for the watershed as follows: 

 

1

 For example see the following sites: Fort Hartford Coal Co. Stone Quarry, EPA ID KYD980844625; National Southwire 

Aluminum Co., EPA ID KYD049062375; Standard Auto Bumper Corp., EPA ID FLD004126520; Coleman-Evans Wood 

Preserving Co., EPA ID FLD991279894; CTS Of Asheville, Inc., EPA ID NCD003149556; Geigy Chemical Corp. 

(ABERDEEN PLANT), EPA ID NCD981927502; Interstate Lead Co. (Ilco), EPA ID ALD041906173; LCP Chemicals 

Georgia, EPA ID GAD099303182; Macalloy Corporation, EPA ID SCD003360476; Red Panther Chemical Company, EPA 

ID MSD000272385; and Woolfolk Chemical Works, Inc., EPA ID GAD003269578. 

 4 
Horton Iron & Metal Co. NPL Listing Support Document September 2011 

• . . . 

• If none of the sources is located in surface water in the watershed, assign a containment 

factor value from table 4–2 to each source at the site that can potentially release 

hazardous substances to the hazardous substance migration path for this watershed. 

Assign the containment factor value for the watershed as follows: 

- Select the highest containment factor value assigned to those sources that meet 

the minimum size requirement described below. Assign this highest value as the 

containment factor value for the watershed. Enter this value in table 4–1. 

- If, for this watershed, no source at the site meets the minimum size requirement, 

then select the highest containment factor value assigned to the sources at the site 

eligible to be evaluated for this watershed and assign it as the containment factor 

value for the watershed. Enter this value in table 4–1. 

A source meets the minimum size requirement if its source hazardous waste quantity value (see 

section 2.4.2.1.5) is 0.5 or more. Do not include the minimum size requirement in evaluating any 

other factor of this surface water migration component, except potential to release by flood as 

specified in section 4.1.2.1.2.2.3. 

HRS Table 4-2 directs the assignment of a containment factor of 10 for the contaminated soil source at a site if 

there is: 

[n]o evidence of hazardous substance migration from source area and: (a) Neither of the following 

present: (1) maintained engineered cover, or (2) functioning and maintained run-on control system and 

runoff management system. 

Thus, a containment factor value of 10 would be assigned unless one of the two controls was documented to be 

present. 

Section 2.2, Source Identification, Containment on page 22 of the HRS documentation record at proposal states 

that “[t]here 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.” 

There is no evidence of a maintained engineer cover and a silt fence does not qualify as a run-on control system 

and runoff management system because it typically only captures large particulate; finer particulate and dissolved 

contaminants may still migrate with runoff through the silt fence. Furthermore, because soil contamination existed 

prior to the installation of the silt fence, contaminants had already migrated to surface water via runoff. The HRS 

documentation record at proposal established contamination in Source 1 based on soil samples collected in 

August 2009 (see section 2.4.1, Hazardous Substances, of the HRS documentation record at proposal), and 

observed releases were based on sediment samples collected in April 2003 and August 2009 (see section 

4.1.2.1.1, Observed Release, of the HRS documentation record at proposal. The agreement to install the silt fence 

was not made until after the releases were established, as documented in a meeting on September 30, 2009 (see 

Attachment 1, October 2009 EPA Letter Regarding Voluntary Actions). Additionally, a silt fence is generally 

only considered a temporary measure. That is, a silt fence would not prevent or obstruct the migration of 

hazardous substances from the source to surface water. Also, the commenter has only claimed that the silt fence is 

a runoff control system; for the second item required by HRS table 4-2 to be satisfied, there must be a “run-on 

control system and runoff management system.” Therefore, the HRS documentation record is correct in its 

assignment of a containment factor value of 10 for Source 1. 

This comment results in no change to the HRS score and no change in the decision to place the Site on the NPL. 

 5 
Horton Iron & Metal Co. NPL Listing Support Document September 2011 

4 Conclusion 

The original HRS score for this site was 48.03. Based on the above responses to public comments, the Site score 

remains unchanged. The final scores for the Horton Iron & Metal Co. site are: 

Ground Water: NS 

Surface Water: 96.06 

Soil Exposure: NS 

Air Pathway: NS 

HRS Score: 48.03

 6 
Horton Iron & Metal Co. NPL Listing Support Document September 2011 

 7 

Attachment 1 

October 2009 EPA Letter Regarding Voluntary Actions
^^^to sr., 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION 4 

ATLANTA FEDERAL CENTER isis 61 FORSYTH STREET . / •U PnQX'iy ATLANTA, GEORGIA 30303-8960 

OCT 2 7 Horton Iron and Metal 

c/o Mr. Ralph Horton, Sr. 

P.O.Box 1285 

Wilmington, North Carolina 28402 

SUBJ: Horton Iron and Metal 

Wilmington, New Hanover County, North Carolina 

Dear Mr. Horton: 

The purpose of this letter is to confirm EPA's understanding ofthe actions you agreed to 

voluntarily perform to control releases of hazardous substances at the above-referenced Site. The 

United States Environmental Protection Agency (EPA) has documented the release or threatened 

release of hazardous substances, pollutants, or contaminants at the Site. On July 21, 2009, EPA 

notified you ofthe potential liability, as defined by Section 107(a) ofthe Comprehensive 

Environmental Response, Compensation, and Liability Act of 1980, 42 U.S.C.§ 9607(a), as 

amended (CERCLA), that you may have incurred with respect to the Site. 

On September 30, 2009, you met with EPA's On Scene Coordinator, Kenneth Rhame to 

discuss actions you can take immediately to reduce worker exposure and prevent contaminants 

from migrating off-site during storm events. 

You agreed to install a gated access to the area consisting ofthe fonner lead acid chambers to 

prevent unauthorized entry into that location. Additionally, you agreed to install a silt fence 

between the former fertilizer acid chamber area and the boat slip to prevent contaminants from 

migrating into the Northeast Cape Fear River. 

Your performance ofthe actions noted above will not preclude EPA from requiring PRPs to 

perform response activities in the fiature pursuant to CERCLA or any other applicable law. 

Unless EPA reaches an agreement under which a potentially responsible party (PRP) or parties 

will properly perform or finance such actions, EPA may perform these actions pursuant to 

Section 104 of CERCLA. 

EPA plans to contact all ofthe PRPs at the Site to discuss additional response actions at the 

Site in the very near fiiture. Pleeise do not hesitate to contact Kenneth Rhame at (919) 475-7397, 

if you have technical questions. I can be reached at (404) 562-9553, if you have legal questions. 

intemet Address (URL) • http://'iVww.apa.gov 10699079 R«cycled/n«cyclabl« . Printed wilh Vogeiable Oil Based Inks on Recycled Paper (Minimum 30% Poslconsumer) 
Legend 

CTT i 1^:-lrrlOo-^'>rt'-'.f.^^rfltoJGr«l j 

1 

. :••.;.. ••.;.•:•• • .; . fi^xx^J.,'^, 

1 ;•;.:•.•...,-' 1 'J ' 

. .•.SKi.(wi..vLL-.-tlo n 

Loatoti' 

Mto.' 

'-•!.•.•-fl- . . .*. ••=.'.• . :• 

Ki.- -rtvt^''-ir«»tac;L-rt-^l 

..S'r = :wtr'l*"::';»'«TM 

• • ^1 1 Mi r 1 

0 23 50 100 rG^ 200 

United Stetae Envtronmenul Protedlon Agency 

HORTON IRON & METAL SITE 

WILMINGTON, 

NEW HANOVER COUNTY. 

NORTH CAROLINA 

TDD No. TTEMI.flS-003.0018 

FIGURE 2 

SOIL SCREENING & 

SAMPLING LOCATIONS 

'Tl, 

- 5 • U /^t' U-'•<: *, vv5l-^- ^ : L< y- Ww_