United States

Environmental Protection 1200 PennsylvaniaAvenue, N.W. Agency Washington, DC 20460 Ma y 20 12

O ce of Solid Waste and Emergency Response 

# EPA

Support Document for the

Revised National Priorities List

Final Rule – Southern Avenue Industrial Area

# Support Document for the

Revised National Priorities List

Final Rule
Southern Avenue Industrial Area

Ma y 2012

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

## 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

................................................................................................ ...................................3

3.1 Support for Listing .....................................................................................................................................3

3.2 Site Name

................................................................................................ ...................................................4

3.3 Liability

................................................................................................ ......................................................4

3.4 Stigma of Listing

................................................................................................ ........................................5

3.5 Extent of Site

................................................................................................ ..............................................5

4. Conclusion

................................................................................................ ........................................................7 Sout hern Avenue Industrial Area NPL Listing Support Document May 2012

iSouthern Avenue Industrial Area NPL Listing Support Document May 2012



## 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 Se ptember 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 Southern Avenue Industrial Area site, proposed on September 16, 2011 (76 FR 57702). 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 Ma y 2012.

iiSouthern Avenue Industrial Area NPL Listing Support Document May 2012



## I ntroduction

This document explains the rationale for adding the Southern Avenue Industrial Area site in South Gate, California, to the National Priorities List (NPL) of uncontrolled hazardous waste sites and also provides the responses to public comments received o n this site. The EPA proposed this site on September 16, 2011 (76 FR 57702). 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 Ma y 2012.



### 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 uncon trolled 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 (4 7 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). Remedia l 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 Tr ust Fund established under CERCLA, were includ ed 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 establishe d 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 28.50 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 15, 2012 (77 FR 15276) . The Agency also has published a number of proposed rulemakings to add sites to the NPL. The most recent proposal was on March 15, 2012 (77 FR 15344).



### Development of the NPL

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

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

ii iSouthern Avenue Industrial Area NPL Listing Support Document May 2012

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 re medial 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 a ssign 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 ap propriate 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 an d 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 de velop HRS scores is not sufficient in itself to determine either the extent of contamination or the appropriate r esponse 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 analy sis approach to scoring sites. This approach assigns numerical values to factors that relate to or indicate risk, ba sed 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 (S gw )

- drinking water

ivSouthern Avenue Industrial Area NPL Listing Support Document May 2012

• Surface Water Migration (S

sw ) The following threats are evaluated for two sepa rate migration components, overland/flood migration and ground water to surface water.

- drinking water

- human food chain

- sensitive environments

• Soil Exposure (S

s )

- resident population

- nearby population

- sensitive environments

• Air Migration (S

a )

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

sites pose thr eats 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 Servic e 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 Southern Avenue Industrial Area site on Septemb er 16, 2011 (76 FR 57702 ). 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 t he site.

vSouthern Avenue Industrial Area NPL Listing Support Document May 2012



### 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

cDCE cis -1,2-dichloroethene

CDCPG Cooper Drum Cooperating Parties Group

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 r egulations

COC Chemicals of concern

D.C. Cir U.S. Court of Appeals for the District of Columbia Circuit

EPA U.S. Environmental Protection Agency , also USEPA

FR Federal r egister

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

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

NPL National Priorities List, Appendix B of the NCP

RI Remedial I nvestigation

RI/FS Remedial Investigation/Feasibility Study

SARA Superfund Amendments and Reauthorization Act

TCE Trichloroe th ene

V OC Volatile organic compound

viSouthern Avenue Industrial Area NPL Listing Support Document May 2012



## 1. List of Commenters and Correspondence

EPA

- HQ

- SFUND -2011-0645-0003 Correspondence, dated May 10, 2011, to Governor Jerry Brown seeking the State of California’s position on the United States Environmental Protection Agency (U.S. EPA) proposed listing

of the Seam Master Industries and the Jervis B. Webb Co. sites on the Superfund National Priorities List ( NPL)

.

EPA

- HQ

- SFUND -2011-0074-0005 Comment and attachment , dated November 3, 2011 , from Carlos Velasquez, public comment er

EPA

- HQ

- SFUND -2011-0074-0006 Comment and attachment , dated November 5, 2011, from Maritza Velasquez, public comment er

EPA

- HQ

- SFUND -2011-0074-0007 Comment and attachment , dated November 5, 2011, from Mehnoosh Anwar, public comment er

EPA

- HQ

- SFUND -2011-0074-0008 Comment and attachment , dated November 1, 2011, from Paul

M. Vidor, President, Seam Master Industries

EPA

- HQ

- SFUND -2011-0074-0009 Comment and attachment , dated November 15 , 2011, from Elizabeth Velasquez, public comment er

EPA

- HQ

- SFUND -2011-0074-0010 Comment and attachment, dated November 15 , 2011, from Daniel E. Vineyard, Jackson W alker L.L.P., Common Counsel, Cooper Drum Cooperating Parties Group (CDCPG)



## 2. Site Description

The Southern Avenue Industrial Area site ( formerly identified as the Seam Master Industries s ite, hereinafter referred to as the Site) comprises ground water c ontamination in South Gate, Los Angeles County, California (see Figure 1) . The Site is located in an urban area, in which numerous drinking water wells are located. The HRS evaluation for the Site scored the ground water migration pathway. The source identified at proposal for HRS purposes is volatile organic compound (VOC)- contaminated soil located in the s outheastern portion of the Site on the Seam Master Industries property, which since 1972, has been operating as a hot

- melt adhesive manufacturing

compan y. The Seam Master Industries property, the location of the source of contamination at this Site

, is located at 5211 Southern Avenue, South Gate, Los Angeles County, California.

The Site was scored based on the finding of soils contaminated with VOCs and the identification of observed

releases of VOCs by chemical analysis to a drinking water aquifer. The observed releases were identified based

on ground water samples collected from five boring locations and t wo monitoring wells throughout the Site area

. The contaminants found were trichloroethene (TCE) and cis-1,2-dichloroethene (cDCE) . Background samples collected upgradient of the Site that draw from the same aquifer showed no-detection or comparatively low

concentrations for these contaminants

.

The HRS target evaluation included e ight drinking water wells located within two miles of the sources at the Site ; the wells were screen ed within the Semi -Perched/Gaspur/Exposition/Gage interconnected Aquifer. These wells were evaluated for potential contamination and provide drinking water to approximately 65,256 people. Four municipalities , which are located within four miles of the sources at the Site and have public water systems

, were scored for potential contam ination . Those water systems include : City of South G ate, Walnut Park Mutual Water Company, Maywood Mutual Water Company #3 and City of Lynwood. The four municipalities serve approximately 188,840 people.

1S o u t h e r n A v

e n u e R a
i l r o a d A
t a
l a n t i c A v e n u e R a y o

A

v e n u e F i r

e

s

t o n e B o u l e

v

a

r d

Gr

o u n d wa

t e r 

# E F l o w D

i r e c t i o n 

### Legend

Property Boundary

+ U Monitoring Well

& . CPT Sample

+

Jervis B. Webb Co. Groundwater Sample Location Property + U with TCE and DCE concentration in micrograms per liter.

MW-10
TCE: 15
DCE: 32 TCE = Trichloroethylene DCE = cis-1,2-Dichloroethene
CPT = Cone Penetration Test MW = Monitoring Well

ND = Not DetectedU Grab Groundwater Sample

Feet

0 400

MW-14
TCE: 0.63
DCE: 3.2

Cooper Drum CPT-20
TCE: 24
DCE: 9

SM-7-GW TCE: 4,100

CPT-21 TCE: 8,000 DCE: 4,900U + Property

MW-10 U + TCE: 15
DCE: 32

CPT-16
TCE: <0.5U & . + U +

& .U +U Seam Master

+ Property DCE: <0.5

SM-1-GW
TCE: 7 MW-34 DCE: 1 TCE: 46
DCE: 420

MW-35
TCE: 120

Base Map: USA Prime Imagery, Los Angeles, Aerials Express 2009. CPT and Well Locations from: Innovative Technical Solutions, Inc., Cooper Drum Company Superfund Site Remedial Design Technicall Memorandum for Field Sampling Results, Addendum No. 4, February 26, 2010. Grab Groundwater Samples Locations from: Weston Solutions, Inc., Preliminary Assessment/Site Inspection Report, Seam Master Industries, South Gate, California, May 8, 2003. & .U

+

SM-8-GW TCE: 4,000

SM-6-GW TCE:1,700

Site Area Map
Southern Avenue Industrial Area South Gate, California Figure SM-9-GW TCE: 17,000 DCE: 8,000 + U U +

1Southern Avenue Industrial Area NPL Listing Support Document May 2012

An adjacent NPL site, t he C ooper Drum Company Superfund Site (Cooper Drum site) (EPA ID: CAD055753370) is located at 9316 Atlantic Avenue in South Gate, California (see Figure 1) . The Co oper Drum facility is located approximately 300 feet northwest and hydraulically upgradient of th e Seam Master property. Contaminants or chemicals of concern (COC) associated with the Cooper Drum facility include TCE and cis-1,2-DCE. The Cooper Drum site was proposed to the NPL on January 11, 2001, and added to the NPL on June 14, 2001.



## 3. Summary of Comments

Six comment submittals were received on the proposal of the Site to the NPL. F ive commenters supported placement of the Site on the NPL. Two c ommenters in support of placement of the Site on the NPL expressed

concern that if the Site is not cle aned up it c ould cause “hazardous health problems.” Two other commenters in support of placement of the Site on the NPL stated that they have see n the negative impacts that high levels of pollution have had on the city and “would hate to see this pattern o f environmental damage continue to happen in this community.”

Cooper Drum Cooperating Parties Group (CDCPG) also supported pla cement of the Site on the NPL. CDCPG stated that it appreciated the EPA’s efforts to fully characterize ground water plum es in the Site area , and

identif ication of the S ite as a major contributor to ground water contamination in South Gate, California. In addition to supporting the listing, CDCPG expressed concerns that close proximity to the Southern Avenue

Industrial Area site has complicated the interpretation of plume boundaries , specifically

, that it objected to the statement in the Site narrative that the plumes from this site and the Cooper Drum site were co mmingled, and requested that certain technical issues related to plume boundaries be clarified.

One commenter contested the listing

– Seam Master Industries

. Seam Masters Industries objected to naming the

s ite Seam Mas ter Industries and requested that any reference to Seam Master Industries be deleted. Seam Master

Indu stries asserted that Seam Master Industries does not own the referenced property nor is in any shape or form responsible for any con tamination. Seam Master Industries added that “ there could be a perception of ‘ guilt by location’ which could damage the reputation of our company, which could have dire consequences in these tough

economic times .”



### 3.1 Support for Listing

Comment : Linda S. Adams, Acting Secretary for Environmental Protection for the State of California , agrees that

the environmental threats id entified need to be addressed, and the State of California supported placement of the

Site on the NPL. The Cooper D rum Cooperating P arties G roup (CDCPG) supported placement of the Site on the

NPL. CDCPG stated that it appreciated the EPA’s efforts to fully characterize ground water plumes in the area of

the Site , and that the EPA identified the Site as a major contributor to the ground water contamination in South Gate, California. CSCPG’s submissio n also included comments regarding whether the plume from this site was commingled with that from the Copper Drum Site; these com ments are addressed in section 3.5 of this support

document.

Four additional commenters , Maritza Valasquez, Mehnoosh Anwar, C arlos Velasquez, and Elizabeth Velasquez, supported placement of the Site on the NPL. Maritza Valasquez and Mehnoosh Anwar, expressed concern that if the Site is ignored and not cleaned up it “can cause hazardous health problems.” Carlos Velasquez and Elizabeth Velasquez stated that “the community is already one of the most polluted in the region” and that they “see the negative impacts that high levels of pollution have had on the city” and they “would hate to see this pattern of environmental damage conti nue to happen in this community.”

3Southern Avenue Industrial Area NPL Listing Support Document May 2012

Response: Southern Avenue Industrial Area site is being added to the NPL. Listing makes a site eligible for remedial action funding under the Comprehensive Environmental Response, Compensation, and Liability Act ( CERCLA ), and the EPA will examine the Site to determine the appropriate response action(s). Actual funding may not necessarily be undertaken in the precise order of HRS scores . In addition, upon more detailed investigation may not be necessary at all in some cases

. The need for using Superfund monies for remedial

activities will be determined on a site-by- site basis, taking into account the NPL ranking, State priorities, further site investigation, other response alternatives, and other factors as appropriate. The EPA will not stop work at some sites to begin work at other higher-scoring sites added to the NPL more recently.

As discussed in the remainder of this support document, all specific comments received on the proposed addition

to the NPL of this site have been addressed and the Site still qualifies for the NPL listing.



### 3. 2 Site Name

Comment : Seam Master Industries objected to naming the s ite Seam Master Industries. Seam Master Industries commented that “any reference to Seam Master Industries be deleted .”

Response : The Site was named Seam Master Industries based on information obtained by the EPA at the time of proposal . T he S ite name has been changed to So uthern Avenue Industrial Area at promulgation to better reflect

the site location and for the location to be more clearly understood by the public. The HRS documentation record at promulgation has been revised to reflect this change. For the limited purpose of the NPL, a s stated in RSR Corporation v. Environmental Protection Agency No. 95-1559 (D.C. Cir. 1997), when naming a site , the “ EPA prefers names that accurately reflect the location or nature of the problems at a site and that are readily and easily associated with the site by the general public“ and that “listing does not require any action of any private party, nor does it determine the liability of any party for the cost of cleanup at the site.”

Concerning the commenter’s request to delete any reference to Seam Master Industries, it would be inappropriate and to some extent misleading to d escribe the Site for public understanding without mention of Seam Master

Industries. The Site Description correctly discusses the history of the Site including the businesses that operated on the Site; therefore Seam Master Industries is appropriately disc ussed in the HRS documentation record at proposal. In as much as this comment concerns liability for contamination at the Site, as discussed in s ection 3.3 of this support document, liability is not considered when evaluating a site under the HRS, nor is l iability established or apportioned based on the decision to place a site on the NPL.

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

NPL.



### 3. 3 Liability

Comment : Seam Master Industries stated that it “has been brought to our attention that the article in your September 2011 publication states that “Seam Master Site” is proposed to be added to the Superfund List.” It

comment ed that “ Seam Master Industries does not own the referenced property nor is in any shape or for m

respo nsible for any contamination referenced in the article published in your September 2011 issue.”

4Southern Avenue Industrial Area NPL Listing Support Document May 2012

Response : In as much as this comment concerns liability for contamination at the Site, l iability is not considered when evaluating a site under the HRS, nor is liability established or apportioned based on the decision to place a site on the NPL. The NPL serves primarily as an informat ional tool for use by the EPA in identifying those sites that appear to present a signific ant risk to public health or the environment. It does not reflect a judgment on the activities of the owner(s) or operator(s) of a site. The listing does not require those persons to undertake any action, nor does it assign any liability to any person. This position, stated in the legislative history of CERCLA, has been explained more fully in the Federal Register (48 FR 40759, September 8, 1983 and 53 FR 23988, June 24, 1988). See Kent County v. EPA, 963 F.2d 391 (D.C. Cir. 1992)

.

If

by “article in your September 2011 publication” Seam Master Industries is referring to the HRS documentation record at proposal, that record does not state that Seam Master Industries owns the referenced property. The HRS documentation record at proposal on page 9 states that “[s]ince 1972, the Seam Master facility has been operating

as a hot

- melt ad hesive manufacturing company.” (See also section 3.2 of this support document regarding the S ite name.)

This comment does not change the HRS site score and do es not change the decision to place the Site on the NPL.



### 3.4 Stigma of Listing

Comment : Seam Master Industries stated that “[u]nfortunately there could be a perception of ‘guilt by location’ which could damage the reputation of our company, which could hav e dire consequences in these tough economic

times.”

Response : Any negative impacts associated with listing the Site, as noted by Seam Master Industries, would be engendered by the contamination in the area, not by plac ing the Site on the NPL

. Inclusion o f a site or facility on the list does not in itself reflect a judgment on the activities of the owner(s) or operator(s), but rather reflects the EPA’s judgment that a significant release or threat of release has occurred and that the site is a priority for further investigation under CERCLA. Bot h costs and benefits can be associated with listing a site. Among the benefits associated with listing a site on the NPL are increased health and environmental protection as a result of increased public awareness of potential hazards. In addition to the potential for federally financed remedial actions, the addition of a site to the NPL could accelerate privately financed, voluntary cleanup efforts. 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.

This comment does not change the HRS site score and does not change the decision to place the Site on the NPL.



### 3.5 Extent of Site

Comments : CDCPG requested that the EPA revise the September 2011 Site narrative and an EPA Fact Sheet ( Seam Mas t er Industries [Southern Ave nue Industrial Area] and Jervis B. Webb Co. Sites Proposed for Superfund

List , September 2011), to reflect that it is not known that the plumes from the Cooper Drum site and the Southern Avenue Industrial Area site commingle. CDCPG identified that the Sout hern Avenue Industrial Area site and the Cooper Drum site are relatively close and share some of the same chemicals of concern (COC). CDCPG commented that close proximity to Southern Avenue Industrial Area site has “complicated the interpretation of ‘plume boundaries’” and requested that certain technical issues related to plume b oundaries be clarified.

CDCPG gave several rationales for why the two plumes might not be commingled:

5Southern Avenue Industrial Area NPL Listing Support Document May 2012

• that the “HRS documentation record at proposal shows that the background COC concentrations at the northwest (upgradient) corner of the Seam Master [Southern Avenue Industrial Area] site, south (downgradient) of the Cooper Drum site, were very low.” Therefore the contamination may not be in high enough concentrations to migrate t o where it might commingle

• that the ground water flow direction is such that the contamination from the sites would not commingle

• that the contaminant mixes in the two plumes are significantly different

.

CDCPG continued that:

Both the CDCPG and [the] EPA acknowledge that the plume boundaries are ambiguous due to the similarity in COCs and close proximity of the Seam Master [Southern Avenue Industrial Area] and other sit es to the Cooper Drum site. Moreover, it is a fact that the Seam Master [Southern Av enue Industrial Area] plume has not yet been characterized and its boundaries are yet to be defined. Thus, it simply is not known whether or not these two plumes actually commingle. Thus, we respectfully request that the statement in the NPL Site Narrative quoted

above be clarif ied to reflect these facts.

Response : The Site for HRS scoring purposes is delineated in the HRS documentation record at proposal as consisting of a source and the releases of hazardous substances to ground water from the Site source

. The potential commingling of ground water plumes associated with this site and the Cooper Drum s ite was not a factor in the development of the HRS Site score and is not relevant to the listing decision for the Site. The full extent of

the Site wil l be determined during other stages of the Superfund process.

However, to reflect that the full extent of the two plumes has not been completely delineated, the EPA Site Narrative has been revised to clarify that the ground water contamination from the So uthern Avenue Industrial Area site appears to be commingling with the down gradient portion of the Cooper Drum plume . The revised Site Narrative is in the docket at promulgation.

The EPA Fact Sheet, Seam Master Industries [Southern Avenue Industrial Area] & Jervis B. Webb Co. Sites Proposed for Superfund List, September 2011, is a published document in the public realm. When the site is finalized, the region will issue a new, and separate, fact sheet reflecting that the plumes possibly commingle. This

new f act sheet will be updated to the site website.

However, that the HRS site evaluation does not rely on the commingling of the two plumes does not mean that the sites may not be found to overlap based on further investigation.

For HRS evaluation purposes, the site is defined in HRS Section 1.1, Definitions , as:

[a]rea(s) where a hazardous substance has been deposited, stored, or placed, or has otherwise come to be located. Such areas may include multiple sources and may include the area between

the sources.

The extent of contamination at the Site is described in the HRS documentation record at proposal by identifying the extent of contamination in ground water samples and establish ing that observed release s have been documented in ground water samples.

The HRS directs the identification of the contaminated areas that constitute the site for scoring purposes. HRS Section 3.1.1, Observed Release

, directs the identification of observed releases to ground water HRS Section 2.2,
Characterize sources

, directs the identification of sources.

6Southern Avenue Industrial Area NPL Listing Support Document May 2012

The extent of the Site for HRS scoring purposes is described on page 9 of the HRS documentation record at proposal as follows: “The [S]ite includes the contaminated soil source and releases of volatile organic compounds (VOCs) and associated ground water contamination, which pose a hazard to people.” The commenter did not

contest the identification of the source or the observed releases at the Site. The scored source is identified as Source 1, contaminated soil at Seam Master Industries, which is described on pages 11 -16 of the HRS documentation record at proposal as “contaminated soils located on the Seam Master property.” Multiple observed releases have been documented in ground water samples collected (pages 22 -31 of the HRS

d ocumentation record at proposal). Specifically page 30 of the HRS documentation record at proposal states:

H azardous substances that meet the criteria for an observed release by chemical analysis were detected in Source 1 (see Section 2.2.2 of this documentation record). Background samples used to evaluate an observed release by chemical analysis are located upgradient of the source at the

Jervis B. Webb site. An observed release of TCE and cis -1,2-DCE is documented from the Seam Master property based on chemical analysis (see above tables in Section 3.1.1 of the HRS documentation record).

In addition, the delineation of the site boundaries is not completed at the time of placing a site on the NPL. As stated in the footnote on page 1 of the HRS documentation record at proposal:

G enerally, 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, the 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.

Until the site investigation pr ocess has been completed and a remedial action (if any) selected, the EPA can neither estimate the extent of contamination at the site, including whether the two plumes have commingled, nor describe the ultimate dimensions of the NPL site. Even during a re medial 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 dis covered elsewhere on the property, the EPA may decide to evaluate that release for the NPL.

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

NPL.



## 4. Conclusion

The original HRS score of this s ite was 50.00. Based on the above responses to public comments, the score remains unchanged. The final scores for the Southern Avenue Industrial Area site are:

Ground Water 100.00

Surface Water Not Scored Soil Exposure Not Scored

Air Not Score d

HRS Site Score 50.00

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