September 2011 HRS DOCUMENTATION RECORD—REVIEW COVER SHEET

Name of Site: SEAM MASTER INDUSTRIES

Contact Person: Karen Jurist , EPA Region 9 (415) 972-3219

Site Investigation: Karen Juri st, EPA Region 9 (415) 972-3219

Documentation Record: Amanda K.C. Re illy, Weston Solutions, Inc. (541) 593-3800

Pathways, Components, or Threats Not Scored

Surface Water Pathway

The surface water pathway was not scored because there are no surface water intakes, fisheries,

or sensitive environments associated with the Los Angeles River downstream of the site. The Los Angeles River is located appr oximately 650 feet east of the s ite and empties into San Pedro Bay approximately 13 miles downstream of the site (Ref. 21, Plate 1; Ref. 23). The Los Angeles River is highly modified, having been lined with concrete along a majority of its length by the U.S. Army Corps of Engineers in the 1950s. Fl ows are dominated by urban runoff and tertiarytreated effluent from several municipal wast ewater treatment plants (Ref. 15, p. 1, 3).

Soil Exposure Pathway

The soil exposure pathway was not scored b ecause there are currently no known resident individuals, sensitive environments , or resources on or within 200 feet of sources at the site. In addition, the majority of the pr operties are covered in pavement and/or buildings. The Seam Master business is currently op erating and workers are present onsite (Ref. 24). However, scoring the soil exposure pathway doe s not affect the listing decision.

Air Migration Pathway

The air pathway was not scored because there is no documented observed release to the atmosphere, and scoring the potential to release to air would not likely cont ribute significantly to

the overall site score.September 2011 1 HRS DOCUMENTATION RECORD

Name of Site: SEAM MASTER INDUSTRIES

EPA ID#: CAN000905902

EPA Region: 9

Date Prepared: September 2011

Street Address of Site*: 5211 Southern Avenue

City, County and State: South Gate , Los Angeles County, California 90280

Topographic Map: South Gate, Californi a USGS 7.5-Minute Quadrangle (Ref. 3)

Latitude: 33 o 56’ 46.24” North Longitude: 118 o 10’ 36.92” West (Ref. 23)

Latitude/Longitude Reference Point: The latitude and longitude were measured from sampling location SM-7, a contaminated soil location (Figure A-3; Ref. 3; Ref. 23).

SCORES

Air Pathway = Not scored

Ground Water Pathway = 100.00

Soil Exposure Pathway = Not scored

Surface Water Pathway = Not scored

HRS SITE SCORE = 50.00

*The street addresses, coordinates, and contaminant locations presented in this HRS documentation record identify the general area where 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 ha s been "deposited, stored, placed, or otherwise come to be located." Generally, HR S 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 bo undaries at the time of scoring will be refined as more information is developed as to where the contamination has come to be located.September 2011 2 HAZARD RANKING SYSTEM

SUMMARY SCORESHEETS

SITE NAME: SEAM MASTER INDUSTRIES

CITY/COUNTY/STATE: South Gate, Los Angeles County, California

EPA ID #: CAN000905902

EVALUATOR: Amanda K. C. Reilly DATE: September 2011

S S 2

Ground Water Migration Pathway Score (S gw ) 100.00 10,000

Surface Water Migration Pathway Score (S

sw ) Not scored Not scored

Soil Exposure Pathway Score (S

s ) Not scored Not scored

Air Migration Pathway Score (S

a ) Not scored Not scored

S gw 2 +S

sw 2 + S

s 2 + S

a 2 XXXXXXX 10,000

(S gw 2 +S

sw 2 + S

s 2 + S

a 2 ) / 4 XXXXXXX 2,500

SQRT ((S gw 2 +S

sw 2 + S

s 2 + S

a 2 ) / 4) XXXXXXX 50.00

SQRT = square rootSeptember 2011 3 TABLE 3-1: GROUND WATER MI GRATION PATHWAY SCORESHEET

Likelihood of Release to an Aquifer Maximum Value Value Assigned

1. Observed Release 550 550

2. Potential to Release

2a. Containment 10

2b. Net Precipitation 10

2c. Depth to Aquifer 5

2d. Travel Time 35

2e. Potential to Release [lines 2a x (2b + 2c + 2d)] 500

3. Likelihood of Release (higher of lines 1 and 2e) 550 550

Waste Characteristics

4. Toxicity/Mobility a 10,000

5. Hazardous Waste Quantity a 10

6. Waste Characteristics 100 18

Targets

7. Nearest Well 50 18

8. Population

8a. Level I Concentrations b 0

8b. Level II Concentrations b 0

8c. Potential Contamination b 1,504

8d. Population (lines 8a + 8b + 8c) b 1,504

9. Resources 5 0

10. Wellhead Protection Area 20 0

11. Targets (lines 7 + 8d + 9 + 10) b 1,522

GROUND WATER MIGRATION SCORE FOR AN AQUIFER

12. Aquifer Score [(lines 3 x 6 x 11)/82,500] c 100 100

GROUND WATER MIGRATION PATHWAY SCORE

13. Pathway Score (S gw ), (highest value from line 12 for all aquifers evaluated) c 100 100

a Maximum value applies to waste characteristics category.

b Maximum value not applicable.

c Do not round to nearest integer.September 2011 4 Reference

Number Description of the Reference

1 Hazard Ranking System (HRS); Fina l Rule, 14 December 1990, Vol. 55, No. 241. 3 p (excerpts) (A complete copy of the HRS Final Rule is also available

at http://www.epa.gov/superfund/sites/npl/hrsres/index.htm ).

2 U.S. Environmental Protection Agency (EPA), Superfund Chemical Data Matrix (SCDM) Methodology, January 2004. 49 p. (excerpts) (A complete copy of the SCDM is available at available at http://www.epa.gov/superfund/site s/npl/hrsres/tools/scdm.htm )

3 U.S. Department of the Interior, U.S. Geological Survey, South Gate Quadrangle, California-Los Angeles County 7.5 Minute series Topographical Map, Photorevised 1981. 1 p.

4 Weston Solutions, Inc., Preliminary Assessment/Site Inspection Report, Seam Master Industries, South Gate, California, May 8, 2003. 787 p.

5 U.S. Environmental Protection Agency, Envirofacts Warehouse CERCLIS query results for the Seam Mast er Industries site (CAN000905902), http://www.epa.gov/enviro/htm l/cerclis/cerclis_query.html , accessed November 2, 2010. 2 p.

6 Los Angeles County Assessor, Detailed Pa rcel Information, Assessor ID No.: 6222-003-010, http://maps.assessor.lacounty.gov , accessed November 2, 2010. 2 p.

7 Los Angeles County Assessor, Parcel Map, Assessor ID No.: 6222-003-010, http://maps.assessor.lacounty.gov , 2003, accessed November 2, 2010. 1 p.

8 County of Los Angeles, Department of Health Services, Hazardous Waste Control Program, Inspection, Seam Master Industries, January 18, 1985. 2 p.

9 County of Los Angeles, Department of Health Services, Hazardous Waste Control Program, Inspection, Seam Master Industries, April 18, 1986. 1 p.

10 County of Los Angeles, Department of Health Services, Order to Company, Seam Master Industries, April 18, 1986. 1 p.

11 Weston Solutions, Inc., Sampling and Anal ysis Plan, Seam Master Industries, September 2002. 68 p.

12 U.S. Environmental Protection Agency (EPA), Superfund Chemical Data Matrix (SCDM) Interim Revised Va lues, October 23, 2006. 1 p. (A complete copy of the SCDM is available at http://www.epa.gov/superfund/site s/npl/hrsres/tools/scdm.htm )September 2011 5 13 Rice, Anitra B. and Reilly, Amanda K.C., Weston Solutions, Inc., Telephone conversation with Ron Hernandez, City of South Gate, reco rded on contact report, January 4, June 22, 2011 and August 22, 2011. 2 p.

14 Jurist, Karen, U.S. Environmental Prot ection Agency Region 9, Photographic Documentation and Observations Report, Seam Master Industries, February 22, 2011. 6 p.

15 Mullin, Mike, “Splash” Stormwater Program Newsletter, City of Los Angeles, Los Angeles River Characterization Study Underway, Fall 2000. 4

p.

16 U.S. Environmental Protection Agen cy, Envirofacts Warehouse CERCLIS query results for the Cooper Drum Co. site (CAD055753370), http://www.epa.gov/enviro/htm l/cerclis/cerclis_query.html , accessed March 28, 2011. 3 p.

17 Innovative Technical Solutions, Inc., Cooper Drum Company Superfund Site Remedial Design Technical Memora ndum for Field Sampling Results, Addendum No. 4, February 26, 2010. 451 pages.

18 Rice, Anitra B. and Reilly, Amanda K.C., Weston Solutions, Inc., Telephone conversation with Martin Gonzalez, Walnut Park Mutual Water Company, recorded on contact, October 29, 201 0 June 30, 2011, and August 18, 2011. 1

p.

19 Rice, Anitra B. and Reilly, Amanda K.C., Weston Solutions, Inc., Telephone conversation with Bob Rohlf, Maywood Mutual Water Company #3, recorded on contact report, December 2, 2010, and August 24, 2011. 1 p.

20 California Department of Water Resources, California’s Groundwater Bulletin 118, Coastal Plain of Los Angeles Groundwater Basin, Central Subbasin, February 27, 2004. 6 p. (excerpts)

21 State of California, Department of Water Resources, Southern District, excerpts of Bulletin No. 104, Planned U tilization of the Ground Water Basins of the Coastal Plain of Los Angeles County, Appendix A, Ground Water Geology, June 1961. 207 p. (including Plat es 1, 2, 3A, 3B, 4, 5, 6A, 6B, 6E and Table 1). (excerpts).

22 URS Group, Inc., Copper Drum Company Remedial Investigation Feasibility Study Report Volume 1, May 15, 2002. 1,087 p.

23 Google Earth, 33 o 56’ 46.24” N, 118 o 10’ 36.92” W, California, http://earth.google.com/, July 6, 2011. 1 p.

24 Seam Master, www.seammaster.com , accessed June 30, 2011. 2 p.September 2011 6 25 Jurist, Karen, U.S. EPA Region IX, Telephone Conversation with Jose Molina, City of Lynwood Public Works, , May 25, 2011. 1 p.

26 KAP Technologies, Inc., SDG Narrativ e, Case No: 38516, SDG No: Y4W26, June 4, 2009. 1,546 p.

27 KAP Technologies, Inc., SDG Narrativ e, Case No: 38516, SDG No: Y4W42, June 2, 2009. 1,536 p.

28 Reilly, Amanda K.C., Weston Soluti ons, Inc., Memorandum Re: Sample Quantitation Limits, June 29, 2011. 5 p.

29 Geology Dictionary, http://geology.com/dictionary/glossary-a.shtml

, accessed June 30, 2011. 2 p.

30 U.S. Environmental Protection Agen cy, Envirofacts Warehouse CERCLIS query results for the Jervis B. Webb Co. site (CAD008339467), http://www.epa.gov/enviro/htm l/cerclis/cerclis_query.html , accessed June 30, 2011. 1 p.

31 National Institute of Environmental Health Sciences, In Situ Bioremediation of TCE, Superfund Research Program, Enhancing and Monitoring the Rates

of Microbial Transformation of Ch lorinated Solvents in Anaerobic Groundwater, http://www.niehs.nih.gov/research/supported/srp/pr oducts/products2_s1_s2.c

fm , accessed June 30, 2011. 3 p.

32 Reilly, Amanda K.C., Weston Solutions , Inc., Memorandum Re: Reference 21 supplemental maps, August 23, 2011. 5 p.September 2011 7 ACRONYM LIST

AST Aboveground Storage Tank bgs below ground surface CERCLIS Comprehensive Environmental Response, Compensation, and Liability Information System

CPT Cone Penetrometer Test

DCA Dichloroethane DCE Dichloroethylene DHS County of Los Angeles, De partment of Health Services DWR State of California Department of Water Resources, Southern District EPA United States Environmental Protection Agency HRS Hazard Ranking System ug/kg micrograms per kilogram ug/l micrograms per liter

NOV Notice of Violation PA/SI Preliminary Assessment/Site Inspection PCE Tetrachloroethylene or Tetrachloroethene RWQCB Regional Water Quality Control Board

Seam Master Seam Master Industries

TCA Trichloroethane TCE Trichloroethylene or Trichloroethene USACE United States Army Corps of Engineers UST Underground Storage Tank VOC Volatile Organic CompoundSeptember 2011 8 NOTES TO THE READER

1. Attachment A contains the following maps:

— Figure A-1: Seam Master Industries Property Location Map

— Figure A-2: Seam Master Industries Facility Layout Map

— Figure A-3: Histor ic Sample Location Map

— Figure A-4: Drinking Water Well and Radius MapSeptember 2011 9 SITE DESCRIPTION

The Seam Master Industries (Seam Master) property is located at 5211 Southern Avenue, South Gate, Los Angeles County, California (Ref. 3; Ref. 4, p. 8; Ref. 5, p. 1). The property occupies approximately 3.85 acres (Ref. 6, p. 1; Ref. 7, p. 1). The Seam Master property location is presented in Figure A-1. The source evaluate d for this HRS documentation record includes

VOC-contaminated soil located in the southeaste rn portion of the property (Ref. 4, p. 12; Figure A-3 of the HRS documentation record). The site includes the contaminated soil source and releases of volatile organic compounds (VOCs) and associated ground water contamination, which pose a hazard to peopl e (see Section 3.1.1).

Since 1972, the Seam Master faci lity has been operating as a hot-melt adhesive manufacturing company (Ref. 4, p. 38). Inspections conducted by the County of Los Angeles Department of Health Services (DHS) in 1985 and 1986 indicate that chlorinate d hydrocarbons were used on the property (Ref. 8, p. 1, Ref. 9, p. 1). Duri ng the 1986 inspection, DHS observed one drum of retrograde trichloroethylene (TCE ). A notice of violation (NOV) was issued at this time due to the illegal storage of retrograde TCE and ordered to properly dispose of the waste (Ref. 9, p. 1; Ref. 10, p. 1).

In 2002, a Preliminary Assessment/Site Inspection (PA/SI) was conducted on the Seam Master property. Ground water beneath the property and so ils on the property were sampled as part of the investigation. Soil samples indicated that TCE and cis-1,2-DCE were detected at concentrations above background concentrations (Ref. 4, p. 12). TCE was detected at a maximum concentration of 17 ug/kg and cis-1,2-DC E was detected at a maximum concentration of 7,100 ug/kg (Ref. 4, p. 434, 452). Ground water samples collected beneath the property indicated that TCE and cis-1,2-DCE were present in ground wa ter at concentra tions significantly above background concentrations. Maximum concen trations of TCE and cis-1,2-DCE detected were 17,000 micrograms per liter (ug/l) and 8,000 ug/l, respectively (Ref. 4, p. 13).

The Cooper Drum Company Superfund Site (E PA ID: CAD055753370) is located at 9316 Atlantic Avenue in South Gate, California (Ref . 16, p. 1-2). The 3.8 acre facility is located approximately 300 feet northwest, and hydraulically upgradient, of the Seam Master property (Ref. 17, p. 7, 8, 67, 70-72; Ref. 23). The Coope r Drum facility activities included drum reconditioning since the 1940s. C ontaminants of concern associ ated with the Cooper Drum facility include TCE and cis-1,2-DCE (Ref. 17, p. 7, 8). The Cooper Drum site was proposed to NPL on January 11, 2001 and received its final listing on NPL on June 14, 2001 (Ref. 16, p. 2). This HRS documentation record is a listing of re leases from the Seam Master site, not from Cooper Drum, that are contributing to a TCE- and cis-1,2-DCE-contaminated ground water plume (see Sections 2.2 and 3.0 of th is HRS documentation record).

Investigations conducted on the Cooper Drum s ite involved sampling ground water beneath and downgradient of the Seam Master property. Between September 1998 and March 2001, ground water sampling was conducted as part of a Phas e 2 remedial investigat ion of the Cooper Drum site and depth-discrete ground wa ter samples were colle cted and analyzed on the Seam MasterSeptember 2011 10 property (Ref. 14, p. 4; Ref. 22, p. 20). Analyti cal results indicated th at ground water beneath the Seam Master property exhibited maximum concentrations of TCE at 16,000 ug/l and cis-1,2- DCE at 4,900 ug/l (Ref. 22, p. 122). In addition, in May 2009, al l new and existing ground water monitoring wells were sampled as part of the c ontinued investigation of the Cooper Drum site. Three of the monitoring wells samples were loca ted on or directly down gradient of the Seam Master property (Ref. 17, p. 15, 68 ). Analytical results indicat ed that ground wa ter directly down gradient of the Seam Master property ex hibited maximum concentrations of TCE at 46 ug/l and cis-1,2-DCE at 420 ug/l (Ref. 17, p. 61, 310).

The Seam Master Industries property is locate d in an urban area, in which numerous drinking water wells are located (Ref. 13; Ref. 18; Ref. 19; Ref. 25; Ref. 32, p. 2; Figures A-1 and A-4 of the HRS documentation record). Ground water c ontamination within the Gaspur aquifer has been identified beneath the Seam Master pr operty (Ref. 4, p. 13, 14; Ref. 17, p. 43, 44, 51, 52; Ref. 22, p. 70). Eight drinking water wells screen ed within the Gage and Exposition aquifers are

located within 4 miles of the source at the site (Ref. 13, p. 2; Re f. 18; Ref. 19; Ref. 21, Plate 3A; Ref. 25). These wells were evaluated for poten tial contamination. Interconnection between the Semi-perched, Gaspur, Exposition, and Gage aquifers is established within 2 miles of the source at the site and therefore are elig ible to be scored as one inte rconnected aquifer (Ref. 1, Section 3.0.1.2.1; Ref. 21, Plates 3A, 6A, and 6E; Ref. 32, p. 2; Figures A-1 and A-2 of the HRS documentation record).September 2011 11 2.2 SOURCE CHARACTERIZATION

2.2.1 SOURCE IDENTIFICATION

Name of source: Contaminated soil at Seam Master Industries Number of source: 1

Source Type : Contaminated Soil

Description and Location of Source (see Figure A-2):

Source 1 consists of contaminat ed soils located on the Seam Master property located at 5211 Southern Avenue in South Gate, Los Angeles C ounty, California (Ref. 4, p. 8, 17; Ref. 5, p. 1; Figures A-1 and A-3 of the HRS documentation record).

Soils contaminated with VOCs associated with th e Seam Master operations have been detected at concentrations above background in soil samp les collected on the property. Samples were collected during the October and November 20 02 PA/SI sampling event (Ref. 4, p. 12). EPA collected soil samples at various depths from seven borings (Ref. 4, p. 12, 13, 34).

The Seam Master property lies on Los Ange les County Assessor Parcel Number 6222-003-010 and is approximately 3.85 acres (Ref. 6, p. 1; Ref. 7, p. 1). The property consists of two enclosed buildings, one partially enclosed building or shed, a pallet manufacturing area, and a paved parking lot. In the northwes t portion of the property are th ree concrete liners that are approximately seven feet deep and covered with chicken wire for safety purposes. Reportedly, aboveground storage tanks occupied the liners prior to 1972. In the southeastern portion of the property is an underground storage ta nk that has, reportedly, not been utilized by Seam Master. In the southeastern portion section of the large enclosed building is a sump (Ref. 4, p. 34, 38). A facility layout is pr esented in Figure A-2.

During the 2002 PA/SI conducted on the Seam Master property, seven borings were drilled in order to collect soil samples. Of the seven bo rings, one boring was locate d offsite in order to obtain a background sample and six borings were located on the Seam Master property. Boring SM-1 was the background sample, and located offsite and north of the Seam Master property, borings SM-3 and SM-4 were located adjacent to the concrete liners in the northwest portion of the property, boring SM-5 was located south of th e concrete liners, and borings SM-7, SM-8 and SM-9 were located in the southeastern portion of the property, adjacent to the sump (Ref. 4, p. 34). Soil samples SM-7-S2 and SM-7-S5 exhibi ted concentrations of TCE and cis-1,2-DCE significantly exceeding background concentrations (Ref. 4, p. 29). Sample locations are presented in Figure A-3.September 2011 12 Source Containment

Release to ground water:

Photographs taken in February 2011 showed that although the Seam Master property is paved, the pavement is in poor condition and contains multiple cracks (R ef. 14, p. 2, 3, 5). In addition, during the 2002 sampling event, th ere was no evidence that a li ner or engineered cover were present at or beneath the ground surface (Ref. 4, p. 48). Precipitation could infiltrate the contaminated soil beneath the pavement. Therefor e, a containment factor value of 10 is assigned (Ref. 1 Sections 2.2.3 and 3.1.2.1 and Table 3-2).

2.2.2 HAZARDOUS SUBSTANCES A SSOCIATED WITH THE SOURCE

Between October 9 and November 5, 2002, a PA/SI was conducted on the Seam Master Industries facility, under the dir ection of the EPA (Ref. 4, p. 12). Soil sample were collected at various depths from seven bori ngs. All samples were analyzed for VOCs using EPA Method OLC03.2 (Ref. 4, p. 13). The data were validated by the United States Army Corps of Engineers (USACE) Quality Assurance Office (Ref. 4, p. 12, 632-638).

Soil samples were collected using a 5 gram dis posable volumetric sampling device, and were collected in triplicate. All samples were sealed using the disposable volumetric sampler and a sealable plastic bag. Sample c ontainers were closed as soon as they were filled, immediately custody sealed, labeled, and placed on ice for shipment to the laboratory (Ref. 11, p. 27).

Summarized below is analytical evidence of cont amination in soil samples associated with the

contaminated soil at the Seam Master Industries site.

Background Concentrations

Source samples were compared to the bac kground sample collected during the respective sampling event. During the PA/SI sampling event conducted in 2002, two background samples were collected from one location and two sampling depths, 2 feet and 5 feet bgs. Samples SM-1-

S2 and SM-1-S5 were collected from the ad jacent west property (Ref. 4, p. 34).

Sample ID Sampling Date Hazardous

Substance Concentration (ug/kg) CRQL (ug/kg) References

TCE 5.4 U 5.4 SM-1-S2 10/29/2002 cis-1,2-DCE 5.4 U 5.4 Ref. 4, p. 633, 641, 653

TCE 5.4 U 5.4 SM-1-S5 10/29/2002 cis-1,2-DCE 5.4 U 5.4 Ref. 4, p. 633, 641, 657

Notes:

CRQL: Contract Required Quantitation Limit ug/kg: micrograms per kilogram U: The analyte was analyzed for but was not detected above th e level of the reported contract required quantitation limit (Ref. 4, p. 634)September 2011 13 TCE: Trichloroethylene

DCE: Dichloroethene

Source Samples

Between October 9 and November 5, 2002, a PA/SI was conducted on the Seam Master Industries facility, under th e direction of the EPA (Ref. 4, p. 12) . A total of 14 soil samples were collected from 7 locations at various depths rang ing from 2 feet to 10 feet bgs (Ref. 4, p. 34, 48). Samples SM-7-S2 and SM-7-S5 were collected from one location at two sampling depths, 2 feet and 5 feet bgs, and TCE and 1,2-cis-DCE were de tected above background concentrations (Ref. 4, p. 29).

Sample ID Sampling Date Hazardous

Substance Concentration (ug/kg) CRQL (ug/kg) References

TCE 7.5 6.5 SM-7-S2 10/30/2002 cis-1,2-DCE 6,100 300 Ref. 4, p. 373, 410, 424, 633

TCE 17 5.5 SM-7-S5 10/30/2002 cis-1,2-DCE 7,100 260 Ref. 4, p. 373, 434, 452, 633

Notes:

CRQL: Contract Required Quantitation Limit ug/kg: micrograms per kilogram TCE: Trichloroethylene

DCE: DichloroetheneSeptember 2011 14 2.4.2 HAZARDOUS WASTE QUANTITY

Tier A: Hazardous Constituent Quantity - Not Evaluated (NE)

The information available is no t sufficient to meaningfully evaluate Tier A, hazardous constituent quantity; therefore it is not possible to adequately determine a hazardous constituent quantity for Source 1 (Ref. 1, Section 2.4.2.1.1). Scor ing proceeds to the evaluation of Tier B, Hazardous Wastestream Quantity (Ref. 1, Sections 2.4.2.1.1 and 2.4.2.1.2).

Hazardous Constituent Quantity Value: NE

Tier B: Hazardous Wastestrea m Quantity- Not Evaluated (NE)

The information available is not sufficient to meaningfully evaluate Tier B, hazardous wastestream quantity; therefore it is not possi ble to adequately determine a hazardous wastestream quantity for Source 1 (Ref. 1, Sec tion 2.4.2.1.2). Scoring proceeds to the evaluation of Tier C, Volume (Ref. 1, Sections 2.4.2.1.2 and 2.4.2.1.3).

Hazardous Wastestream Quantity Value: NE

Tier C: Volume

The information available is not sufficient to mean ingfully evaluate Tier C, volume; therefore it is not possible to adequate ly determine a volume for Source 1 (Ref. 1, Section 2.4.2.1.3). Scoring proceeds to the evaluation of Tier D, Area (Ref. 1, Sections and 2.4.2.1.3 and 2.4.2.1.4).

Volume Assigned Value: 0

Tier D: Area

The area of contaminated soil is unknown, but greater than 0. Anal ytical results of the 2002 soil sampling effort indicate the presence of contam inated soil in the southeastern portion of the property (boring SM-7) (Ref. 1, Section 2.4. 2.1.4; Ref. 4, p. 17; Figure A-3 of the HRS documentation record).

Area Assigned Value: >0September 2011 15 Source Hazardous Waste Quantity Value

According to the Hazard Ranking System (HRS), the highest of the values assigned to the source for hazardous constituent quantity (Tier A), haza rdous wastestream quantity (Tier B), Volume (Tier C), and Area (Tier D) should be assigne d as the source hazardous waste quantity value (Ref. 1, Section 2.4.2.1.5).

Tier Evaluated Source 1 Values

A NE

B NE

C 0

D >0*

Note:

* Value selected for the source hazardous waste quantity value, according to the HRS.

NE Not Evaluated.

Source Hazardous Waste Quantity Value: >0September 2011 16 SITE SUMMARY OF SOURCE DESCRIPTIONS

Containment Source

No. Source Hazardous Waste Quantity

Value Ground

Water Surface

Water Gas Air

Particulate

1 >0 10 NE NE NE

TOTAL >0

Notes:

NE = Not Evaluated.September 2011 17 POSSIBLE SOURCES NOT SCORED

• Three concrete liners/former aboveground storag e tanks (ASTs). The concrete liners are

located in the northwest corner of the Seam Master property (Ref. 4, p. 9, 38). The liners are approximately 7 feet deep and covered with chicken wire for safety purposes. During the 2002 PA/SI conducted on the Seam Master property, nothing was observed inside the concrete liners. However, the business manage r stated that ASTs were inside the liners prior to 1972, when a screw manufacturer operated on the property (Ref. 4, p. 38, 46, 47).

• White holding tanks. During the 2002 PA/SI conducted on the Seam Master property, three aboveground white holding tanks were ob served along the eastern portion of the property. They were currently not in use (R ef. 4, p. 44). However, previous businesses may have utilized the tanks for hazardous substances.

• Underground storage tank. The underground storage tank (UST) is located in the southeastern portion of the pr operty (Ref. 4, p. 9, 38). As of 2002, the UST was not used for Seam Master operations and the business manager suspected that it was utilized by prior tenants for gasoline pr oducts (Ref. 4, p. 9, 38).September 2011 18 3.0 GROUND WATER MIGRATION PATHWAY

3.0.1 GENERAL CONSIDERATIONS

The Seam Master facility is located in the Cent ral Basin Pressure Area of the Central Basin of the Los Angeles Coastal Plain (Ref. 20, p. 1; Re f. 21, pp. 130, 166, Plate 2; Ref. 22, p. 32, 33; Ref. 32, p. 2; Figure A-1 of the HRS documen tation record). Ground water is found in the Recent Alluvium, Lakewood Formation, and San Pedro Formation (Ref. 21, p. 188; Ref. 22, p. 33). Geologic materials in the unsaturated zone of the Recent Alluvium , between ground surface and the top of the Lakewood Formation are primarily composed of sandy si lts to silty clays and have been described as correlating with the Be llflower Aquiclude (Ref. 17, p. 8, 101 - 103; Ref. 21, p. 168, 169). An aquiclude is defined as a subs urface rock, soil, or sediment unit that does not yield useful quantities of water (Ref. 29, p. 1). Interbedded within the Bellflower Aquiclude are discontinuous lenses of silty-sands that may allow for the presence of one or more perched aquifers. The groundwater flow direction within these perched aquifers is sensitive to lithologic variations, groundwater extraction, and/or surface water recharge (Ref. 17, p. 8, 10; Ref. 20, p. 1- 3; Ref. 21, p.168)

In the South Gate area, shallow ground water occu rs at a depth of appr oximately 45 feet bgs, with a ground water flow directi on to the south or southeast. Shallow ground water beneath the Seam Master property is expected to be similar to the nearby Cooper Drum Company property,

where it occurs within or is controlled by the near su rface Bellflower Aquiclude, which incorporates the Semi-perched A quifer (Ref. 17, p. 8, 9; Ref. 22, p. 18, 19). In the vicinity of the facility, the Lakewood Formation, which immediat ely underlies the Recent Alluvium, consists of the Gaspur Aquifer, Exposition Aquifer, an unna med aquiclude, and the Ga ge Aquifer. Ground water flow within the Gaspur Aquifer is generall y to the south beneath the Seam Master facility (Ref. 17, p. 70 – 72). Alt hough data are not adequate to document ground wa ter flow within the Exposition and Gage aquifers, it is assumed that the flow direction would be generally towards the south, in the direction of the Pacific Ocean (Ref. 20, p. 2). The San Pedro Formation, which

underlies the Lakewood Formati on, consists of the Hollydale, Jefferson, Lynwood, Silverado, and Sunnyside Aquifers with intervening aquitards [Ref. 21, p. 182, 183, 184, Plate 6A (Geologic Section B-B’); Figures A-1 and A-2 of the HRS documentation record]. The main hydrogeologic features identified beneath the Seam Master facility include the Bellflower Aquiclude, the Semi-perched Aquifer, and the Ga spur, Exposition, and Ga ge Aquifers. These latter units constitute a shallow aquifer and two deeper aquifers, respectively. (Ref. 17, p. 8; Ref. 21, p. 182; Ref. 22, p. 19; Ref. 32, p. 2; Figures A-1 and A-2 of the HRS documentation record).

It appears that the Lakewood and San Pedro fo rmations may not be in hydraulic continuity

within 2 miles of the Seam Ma ster facility [Ref. 21, p. 166, Plat es 3A, 6A (Geologic Section BB’), 6E (Geologic Section L-L’); Ref. 32, p. 1- 2]. In the late 1950s, the State of California Department of Water Resources, Southern Distri ct (DWR), compiled 50 geologic sections for the Los Angeles Coastal Plain (Ref. 21, p. 2, 3, 20). Th e geologic sections were compiled in order to complete a geologic picture of the Coastal Plai n of Los Angeles County. These sections areSeptember 2011 19 based on electric logs and dril lers’ logs from approximately 200 oil wells and 3,500 water wells (Ref. 21, p. 20). Examination of DWR geologic sections B-B’ and L-L’ suggests that the lowermost aquifer in the Lakewood Formation (i .e., the Gage aquifer) is separated from the uppermost aquifer in the San Pedro Formation (i.e., the Hollydale a quifer) by a laterally continuous lower permeability layer in the vicin ity of the property [Ref . 21, p. 166, Plates 3A, 6A (Geologic Section B-B’), 6B (Geologic Sec tion C-C’)]. Interconnect ions between the Semiperched, Gaspur, Exposition, and Gage aquifers is established within 2 miles of the source at the site and therefore are eligible to be scored as one interconnected aquifer (Ref. 1, Section 3.0.1.2.1; Ref. 21, Plates 3A, 6A, and 6E; Ref. 32, p. 2; Figures A-1 and A-2 of the HRS documentation record). Since data are not adequa te to establish aquifer interconnection between

the Lakewood and San Pedro formations within 2 miles of the Seam Master facility (see preceding paragraph) and an observed release is documented to the Semi-perched, Gaspur, Exposition, and Gage aquifers [see Section 3.1.1 (O bserved Release) of this HRS documentation record], the following hydrogeologic discussion is limited to those strata that have been

identified in the Recent Alluvium and Lakewood Formation.

- Stratum 1: Bellflower Aquiclude and Semi-Perched Aquifer

The Bellflower Aquiclude extends from the surface to a depth of approximately 55 to 70 feet bgs and consists of sandy silts, clayey silts, and le sser amounts of silty clay. The semi-perched aquifer is present within the Bellflower Aqui clude. Water levels are generally found in a laterally continuous 5-foot-thick silty/sandy unit at approximately 35 to 40 feet bgs, which is underlain by finer materials of the Bellflower Aquiclude (Ref. 17, p. 8; Ref. 22, p. 34, 35). The Bellflower Aquiclude does not restrict ground wate r movement between the strata composing the aquifer (Ref. 17, p. 52, 61,101 - 103, 165, 166; Re f. 21, pp. 62, 63, 72, 73, 77, 168, 169, 184, 185).

- Stratum 2: Gaspur Aquifer

The shallow aquifer is represented by the Ga spur Aquifer which underlies the Bellflower Aquiclude and extends to a depth of approximately 110 to 120 feet bgs. The Gaspur Aquifer is of fluvial origin and occurs within an ancestral Los Angeles River channel. The Gaspur Aquifer consists of sandy units varying from very fine to medium and coarse and to a lesser extent finer units comprising silty sand and sandy silt. Water level in the Gaspur Aquifer is generally at a depth that corresponds to the Lower Bellflower Aquiclude, suggesting the Gaspur Aquifer is a semi-confined aquifer (Ref. 17, p. 8, 101 - 103; Ref. 22, p. 34). The horizontal flow direction in the Gaspur Aquifer is toward the south (Ref. 17, p. 9).

- Stratum 3: Exposition Aquifer

The Exposition Aquifer, which underlies the Gaspur Aquifer, begins at a depth of approximately 110 to 120 feet bgs (Ref. 17, p. 8). The maximu m thickness of the Exposition Aquifer is 100 feet and is reportedly related to the ancestral Los Angeles River drainage system. MaterialsSeptember 2011 20 range in size from coarse gravels to clay, with the fine deposits separa ting the lenticular sandy and gravelly beds. The upper coarse members of the Exposition appear to have been either eroded and backfilled by the overlying Gaspur Aquifer deposits, or some of the upper members were deposited contemporaneously with the fo rmation of the younger Gaspur Aquifer (Ref. 22, p. 34).

- Stratum 4: Unnamed Aquiclude

Based on DWR Geologic Section B-B’, a lower permeability layer underlies the Exposition aquifer beneath the Seam Master fa cility. It extends from approxi mately 160 feet bgs to 200 feet bgs [Ref. 21, Plates 3A, 6A (Geologic Sect ion B-B’); Figures A- 1 and A-2 of the HRS documentation record].

- Stratum 5: Gage Aquifer

The Gage aquifer generally consists of fine-grained sand and silty sand in the Central Basin Pressure Area (Ref. 21, p. 183, 184). This aquife r underlies the unnamed aquiclude and extends from 200 feet bgs to 275 feet bgs beneath the Seam Master faci lity [Ref. 21, Plates 3A, 6A (Geologic Section B-B’)].

- Aquifer Interconnection

Interconnection between the Semi-Perched, Ga spur, Exposition, and Gage Aquifers is

established within 2 miles of Source 1 at the property as follows (Ref. 1, Section 3.0.1.2.1):

• Contamination has been documented in two monitoring wells (MW-34 and MW-35) located directly downgradient of the Seam Master facility (Ref. 17, p. 15, 38, 61, 68, 310, 311). Monitoring wells MW-34 and MW-35 ar e screened within the Gaspur Aquifer (Ref. 17, p. 8, 38, 51). This supports that th e Bellflower Aquiclude and Semi-perched Aquifer are interconnected to the underlying forma tions (i.e., Lakewood Formation) since contaminants have passed thr ough to the lower aquifers.

• An examination of DWR Geologic Sections B- B’ and L-L’ indicates that the Gaspur Aquifer is in direct contact with the Expositi on Aquifer in the property vicinity (Ref. 21, Plates 3A, 6A, and 6E; Ref. 32, p. 2; Figures A-1 and A-2 of the HRS documentation record).

• An examination of DWR Geologic Section B- B’ indicates that the unnamed aquiclude between the Exposition and Gage Aquifers is not continuous within 2 miles of the Seam Master facility. This aquicl ude is shown as pinching out approximately 1,500 feet to the west of the property, resulting in a merging of the two aquifers [Ref. 1, Section 3.0.1.2.1; Ref. 21, Plates 3A and 6A (Geologic Section B-B’); Ref. 32, p. 2; Figures A-1 and A-2 of the HRS documentation record].September 2011 21 - Aquifer Discontinuities

An examination of DWR Plate 3A indicate that the Seam Master facility is located between Geologic Sections B-B’ and C-C’ that run generally southwest-northeast, and between Geologic

Sections K-K’ and L-L’ that run generally northwest-south east (Ref. 21, Plate 3A). An examination of Geologic Sections B-B’, C-C’, K-K’ an d L-L’ show that there are no aquifer discontinuities between the Semi-Perched and Gage aquifers within 4 miles of Source 1 at the Seam Master site (Ref. 1, Section 3.0.1.2.2; Ref. 21, Plate 6A, Plate 6B, Plate 6E; Ref. 32, p. 2; Figures A-1 and A-2 of the HRS documentation record).

SUMMARY OF AQUIFER BEING EVALUATED

Aquifer

No. Aquifer Name Is Aquifer

Interconnected with Upper Aquifer within 2 miles? (Y/N/NA) Is Aquifer

Continuous

within 4-mile TDL? (Y/N) Is Aquifer

Karst? (Y/N)

1 SemiPerched/Gaspur/ Exposition/Gage Y Y N

Notes:

Y: Yes

N: No NA: Not applicableSeptember 2011 22 3.1 LIKELIHOOD OF RELEASE

3.1.1 OBSERVED RELEASE

Aquifer Being Evaluated: Semi -Perched/Gaspur/Exposition/Gage

Chemical Analysis

2000 Investigation Sampling

Between September 1998 and March 2001, ground water sampling was conducted on the Seam Master property as part of a Phase 2 remedial investigation of th e Cooper Drum site. As part of the investigation, cone penetrometer test (C PT) borings were drilled on the Seam Master property and depth-discrete gr ound water samples were collected and analyzed (Ref. 14, p. 4; Ref. 22, p. 20). All samples were analyzed for VOCs by gas chromatography/mass spectrometry (GC/MS) Regional Analytical Program/non-Contra ct Laboratory Program low-level volatile organics analysis with 25 mL purge (Ref. 22, p. 55, 63, 849, 855).

Ground water sample locations are shown in Figure A-3 and Reference 22, page 68.

- Background Concentrations:

Background levels for site-related VOC hazardous substances are established below based on the analytical results from ground water collectedfrom borings CPT-16 and CPT-20. Boring CPT16 was located northwest of the Seam Master property adjacent south to the ELG Metals building, upgradient of the Seam Master pr operty production wareh ouse and raw material storage and downgradient of the Copper Drum and Jervis properties. Boring CPT-20 was located in the northeast portion of the Seam Master property, upgradient of the Seam Master production warehouse and raw materi al storage and downgradient of ELG Metals (Ref. 22, p. 51, 68, 83).

Ground water collected from borings CPT-16 a nd CPT-20 are used to establish background levels for the contaminated ground water sample collected from boring CPT-21 listed below. Data are compared to background samples collected during the same sampling event using the same methodology. All ground water samples were co llected using a drive sampler. The drive sampler is driven into undisturbed soil beneath the bottom of a borehole. When at the desired depth, the sampler is pulled back approximately one foot to expose the scr een on the sampler. Depth-discrete ground water samples are colle cted by lowering a bail er down the sampling device, retrieving the bailer and transferring the ground water sample to the sample container (Ref. 22, p. 55). The ground water samples presented below were collected at depths between 60 and 65 feet bgs (Ref. 22, p. 122).September 2011 23 Sample ID Sample Depth (ft bgs) Sampling

Date Hazardous

Substance Concentration (ug/l) CRQL (ug/l) References

TCE 0.5 U 0.5

CPT-16 60 10/10/2000 cis-1,2-DCE 0.5 U 0.5 Ref. 22, p. 122, 415, 651, 843, 844, 855,

849

TCE 24 0.5

CPT-20 64 10/9/2000 cis-1,2-DCE 9 0.5 Ref. 22, p. 122, 417, 649, 847, 848, 849,

855

Notes:

CRQL: Contract Required Quantitation Limit ft bgs: feet below ground surface ug/l: micrograms per liter U: The analyte was analyzed for but was not detected above the level of the reported sample quantitation limit

- Contaminated Samples:

The boring listed below is located downgradient of the source at the Seam Master facility. For conservative purposes, the higher concentrat ion background levels from the October 2000 sampling event (CPT-20) are compared to the Oc tober 2000 contaminated sample in order to establish a release. Sample locations are pr esented in Figure A-3 and Reference 22, page 68.

Sample ID Sample Depth (ft bgs) Sampling

Date Hazardous

Substance Concentration (ug/l) CRQL (ug/l) References

TCE 8,000 0.5

CPT-21 63 10/9/2000 cis-1,2-DCE 4,900 0.5 Ref. 22, p. 122, 418, 649, 849, 851, 852,

855

Notes:
CRQL: Contract Required Quantitation Limit ft bgs: feet below ground surface ug/l: micrograms per liter

2002 Seam Master PA/SI Ground Water Sampling

In 2002, ground water sampling was conducted as pa rt of the PA/SI inve stigation on the Seam Master property. Ground water samples were collected from one monitoring well and five borings. All samples were analyzed for VOCs using EPA Method OLM04.2 (Ref. 4, p. 12, 13, 14).

Ground water sample locations are shown in Figure A-3 and Reference 4, page 33.

- Background Concentrations:

Background levels for site-related VOC hazardous substances are established below based on the analytical results from ground water collected from boring SM-1 and monitoring well MW-14. Boring SM-1 was located northwest of the S eam Master property on the CEE SportswareSeptember 2011 24 property, upgradient of the S eam Master property and downgradient of the Cooper Drum and Jervis properties. Monitoring we ll MW-14 is located north of the Seam Master property on the ELG Metals property, upgradient of the Seam Mast er property and downgr adient of the Jervis property (Ref. 4, p. 8, 33; Ref. 17, p. 68, 70).

Ground water samples collected from boring SM-1 and monitoring well MW-14 are used to establish background levels for the contaminated ground water sa mples collected from borings

SM-6-GW and SM-7-GW listed below. Data ar e compared to background samples collected during the same sampling event using simila r sampling methodology. Monitoring well MW-14 was purged at an average rate of approximately 0.3 gallons pe r minute for 97 minutes using a submersible pump. After purgi ng was complete, ground water was sampled using a disposable bailer (Ref. 4, p. 13, 14, 50, 51). Boring SM-1 was drilled and when ground water was encountered, an in-situ ground water sample was collected using a water sampling device. The water sampling device is inserted into undisturbed sediments at th e base of the borehole. The outer portion of the water sampling device is then retracted to expose a stainless steel screen in the water-bearing zone. A stainless steel mini-bailer is lowered into the screen for collection of an in-situ ground water sample. All samples we re collected into pre-preserved 40-mL vials which were immediate capped and inverted to ch eck for air bubbles to en sure zero headspace (Ref. 11, p. 27).

Sample

ID Well

Screened

Interval (ft bgs) Sampling

Date Hazardous

Substance Concentration (ug/l) CRQL (ug/l) References

TCE 7 0.5 SM-1-GW 45 – 65 10/29/2002 cis-1,2-DCE 1 0.5 Ref. 4, p. 345- 351, 355; Ref. 11, p. 22

TCE 58 0.5

MW-14 30 – 60 11/5/2002 cis-1,2-DCE 330 0.5 Ref. 4, p. 333- 339; Ref. 17, p. 37

Notes:

CRQL: Contract Required Quantitation Limit ft bgs: feet below ground surface ug/l: micrograms per liter

- Contaminated Samples:

The borings listed below are located downgradient of the source at th e Seam Master facility. For conservative purposes, the higher concentration background levels from the November 2002 sampling event (MW-14) are compared to the Oc tober 2002 contaminated sample in order to establish a release. Sample locations are pr esented in Figure A-3 and Reference 4, page 33.

Sample

ID Well

Screened

Interval (ft bgs) Sampling

Date Hazardous

Substance Concentration (ug/l) CRQL (ug/l) References

SM-6-GW 45 – 65 10/29/2002 TCE 1,700 0.5 Ref. 4, p. 345- 350; 353, 355; Ref. 11, p. 22September 2011 25 Sample

ID Well

Screened

Interval (ft bgs) Sampling

Date Hazardous

Substance Concentration (ug/l) CRQL (ug/l) References

SM-7-GW 45 – 65 10/30/2002 TCE 4,100 0.5 Ref. 4, p. 345- 350; 353, 355; Ref. 11, p. 22

SM-8-GW 45 – 65 10/29/2002 TCE 4,000 0.5 Ref. 4, p. 345- 350; 353, 355; Ref. 11, p. 22

TCE 17,000 0.5 SM-9-GW 45 – 65 10/30/2002 cis-1,2-DCE 8,000 0.5 Ref. 4, p. 345- 350; 353, 355; Ref. 11, p. 22

Notes:

CRQL: Contract Required Quantitation Limit ft bgs: feet below ground surface ug/l: micrograms per liter

2009 Investigation Sampling

Between May 12 and 19, 2009, all new and exis ting ground water monitoring wells were sampled as part of the continued investigation of the Cooper Drum site. Two of the monitoring wells sampled were located directly down gradient of the Seam Master property (Ref. 17, p. 15, 68). All samples were analyzed for VOCs using EPA Method SOM01.2 (Ref.17, p. 15; Ref. 26, p. 1; Ref. 27, p. 1).

Ground water sample locations are shown in Figure A-3 and Reference 17, page 68.

- Background Concentrations:

Background levels for site-related VOC hazardous substances are established below based on the analytical results from ground water collected from monitoring wells MW-10 and MW-14.

MW-10 is located in the southw est portion of the ELG Metals property, upgradient of the Seam Master property and downgradient of the Cooper Drum and Jervis properties. Monitoring well

MW-14 is located north of the Se am Master property on the ELG Metals property, upgradient of the Seam Master property and downgradient of the Jervis property (Ref. 17, p. 68, 70).

Monitoring wells MW-10 and MW-14 are used to establish bac kground levels for the contaminated monitoring wells listed below. Background and downgradient monitoring wells are screened within the Gaspur aquifer (R ef. 17, p. 43, 44, 51, 52). Data are compared to background samples collected during the same sampling event using the same methodology. The sampling protocol employed standard low- flow ground water sampling techniques with a flow-through cell. The monitori ng wells were sampled using 2- inch pumps with disposable discharge tubing. All samples were transported in a cooler packed with ice, under chain-ofcustody protocol (Ref. 17, p. 15).September 2011 26 Sample ID Well

Screened

Interval (ft bgs) Sampling

Date Hazardous

Substance Concentration (ug/l) SQL (ug/l) References

TCE 15 0.5

MW-10 45 – 74.5 5/14/2009

cis-1,2-DCE 32 2.5 Ref. 17, p. 37, 56, 280; Ref. 26, p. 13, 135, 158; Ref. 28, p. 2

TCE 0.63 0.5

MW-14 30 - 60 5/14/2009

cis-1,2-DCE 3.2 0.5 Ref. 17, p. 37, 57, 282; Ref. 26, p. 13, 198, 199; Ref. 28, p. 2

Notes:

ft bgs: feet below ground surface ug/l: micrograms per liter U: The analyte was analyzed for but was not detected above the level of the reported sample quantitation limit SQL: Sample Quantitation Limit. The SQLs provided in this ta ble are CLP contract-required qua ntitation limits (CRQLs) for that analyte with any dilution factors, volume adjustment s, or percent solids for that analysis ta ken into account. SQLs were calculated as

follows:

( ) DF x (mL) volume initial (mL) volume final

x L μ g CRQL / SQL ⎟ ⎠ ⎞ ⎜ ⎝ ⎛

= Lμg

Where:

Final volume (mL) is the final extr act volume following sample preparation Initial volume (mL) is the volume of sample used

DF is the dilution factor

- Contaminated Samples:

The wells listed below are located downgradient of the sources at the Seam Master facility. For conservative purposes, the higher concentration background levels from the May 2009 sampling event (MW-10) are compared to the May 2009 cont aminated sample in order to establish a

release. Well locations are presented in Figure A-3, Refere nce 17, page 68 and Reference 22, page 68.

Sample ID Well

Screened

Interval (ft bgs) Sampling

Date Hazardous

Substance Concentration (ug/l) SQL (ug/l) References

TCE 46 E 0.5

MW-34 58 - 68 5/16/2009

cis-1,2-DCE 420 E 0.5 Ref. 17, p. 38, 61, 310; Ref. 27, p. 12, 306, 307; Ref. 28, p. 2

MW-35 95 - 105 5/16/2009 TCE 120 5.0 Ref. 17, p. 38, 61, 311; Ref. 26, p. 14, 257; Ref. 28, p. 2

Notes:

E: Concentration exceeds upper level of inst rument calibration range (Ref. 17, p. 63)September 2011 27 ft bgs: feet below ground surface ug/l: micrograms per liter SQL: Sample Quantitation Limit. The SQLs provided in this ta ble are CLP contract-required qua ntitation limits (CRQLs) for that analyte with any dilution factors, volume adjustment s, or percent solids for that analysis ta ken into account. SQLs were calculated as

follows:

( ) DF x (mL) volume initial (mL) volume final

x L μ g CRQL / SQL ⎟ ⎠ ⎞ ⎜ ⎝ ⎛

= Lμg

Where:

Final volume (mL) is the final extr act volume following sample preparation Initial volume (mL) is the volume of sample used

DF is the dilution factorSeptember 2011 28 Attribution

The Seam Master property is located at 5211 Southern Avenue, South Gate, Los Angeles County, California (Ref. 3; Ref. 4, p. 8; Ref. 5, p. 1). The prop erty occupies approximately 3.85 acres (Ref. 6, p. 1; Ref. 7, p. 1). The Seam Mast er property location is pr esented in Figure A-1.

Since 1972, the Seam Master property has been operating as a hot-melt adhesive manufacturing company (Ref. 4, p. 38). Inspections conducte d by the DHS in 1985 and 1986 indicate that chlorinated hydrocarbons were used on the prope rty (Ref. 8, p. 1, Ref. 9, p. 1). During the 1986 inspection, DHS observed one drum of retrograde TC E. A NOV was issued at this time due to the illegal storage of retrograd e TCE and Seam Master was orde red to properly dispose of the waste (Ref. 9, p. 1; Ref. 10, p. 1).

In the South Gate area, shallow ground water occu rs at a depth of appr oximately 45 feet bgs, with a ground water flow directi on to the south or southeast. Shallow ground water beneath the Seam Master property is expected to be similar to the nearby Cooper Drum Company property,

where it occurs within or is controlled by the near su rface Bellflower Aquiclude, which incorporates the semi-perched aquifer (Ref. 17, p. 8, 9; Ref. 22, p. 18, 19). In the vicinity of the Seam Master facility, the Lakewood Formati on, which immediately underlies the Bellflower Aquiclude, consists of the Gas pur aquifer, Exposition aquifer, an unnamed aquitard, and the Gage aquifer. Ground water flow within the Gaspur aquifer is generally to the south beneath the Seam Master facility (Ref. 17, p. 70 – 72). Although data are not adequate to document ground water flow within the Exposition and Gage aquifers , it is assumed that the flow direction would be generally towards the south, in the directi on of the Pacific Ocean (Ref. 20, p. 2; Ref. 21, p. 182, 183, 184, Plate 6A (Geologic Section B-B’); Ref. 23; Ref. 32; Figures A-1 and A-2 of the HRS documentation record).

The Cooper Drum site (EPA ID: CAD055753370) is located at 9316 Atlantic Avenue in South Gate, California (Ref. 16, p. 1-2). The 3.8 acre facility is located approximately 300 feet northwest, and hydraulically upgradient, of th e Seam Master property (Ref. 17, p. 7, 67, 70-72; Ref. 23). The Cooper Drum facility activities included drum reconditioning since the 1940s.

Contaminants of concern associ ated with the Cooper Drum fac ility include TCE and cis-1,2- DCE (Ref. 17, p. 7, 8). The Cooper Drum si te was proposed to NP L on January 11, 2001 and received its final listing on NPL on June 14, 2001 (Ref. 16, p. 2). This HRS documentation record is a listing of releases from the Seam Master s ite, not from Cooper Drum, that are contributing to a TCE- and cis-1,2-DCE-contamin ated ground water plume (see Sections 2.2 and 3.0 of this HRS documentation record).

The Jervis B. Webb Co. site (EPA ID: CAD008339467) is located at 9301 Rayo Avenue in South Gate, California (Ref. 30, p. 1). The 3.82 acre facility is located approximately 750 feet north, and hydraulically upgradient , of the Seam Master proper ty (Ref. 17, p. 67, 70 – 72; Ref. 23). Investigations of the Jervis B. Webb Co. site have been conducted by EPA due to TCE and PCE ground water contamination. (Ref. 17, p. 21)

In 2002, a PA/SI was conducted on the Seam Ma ster property. Gro und water beneath the property and soils on the property were sampled as part of the inves tigation. Soil samples indicated that TCE and cis-1,2 -DCE were detected at c oncentrations above backgroundSeptember 2011 29 concentrations (Ref. 4, p. 12). TCE was detected at a maximu m concentration of 7.5 ug/kg and cis-1,2-DCE was detected at a maximum con centration of 6,100 ug/kg (Ref. 4, p. 410, 424).

Photographs taken in February 2011 showed th at although a majority of the Seam Master property is paved, the pavement is in poor cond ition and contains multiple cracks (Ref. 14, p. 2, 3, 5). In addition, during the 2002 sampling even t, there was no evidence that a liner or engineered cover were present at or beneath the ground surface (Ref. 4, p. 48). Precipitation

could infiltrate the contaminated soil beneath the pavement.

Ground water samples collected beneath the prop erty during the 2002 PA/SI indicated that TCE and cis-1,2-DCE were present in ground water at concentrations significantly above background

concentrations. Maximum concentrations of TCE and cis-1,2-DCE detected were 17,000 ug/l and 8,000 ug/l, respectively (Ref. 4, p. 13). The maximum contaminant level (MCL) is 5 ug/l for TCE and 70 ug/l for cis-1,2-DCE (Ref. 2). Background levels for Seam Master-related VOC

hazardous substances were established based on the analytical results from ground water collected from boring SM-1 and monitoring well MW-14. Boring SM-1 was located northwest of the Seam Master property on the CEE Sports ware property, upgradient of the Seam Master property and downgradient of the Cooper Drum a nd Jervis properties. Monitoring well MW-14

is located north of the Seam Ma ster property on the ELG Meta ls property, upgradient of the Seam Master property and downgradient of the Je rvis property (Ref. 4, p. 8, 34; Ref. 17, p. 68, 70).

Investigations conducted on the Cooper Drum s ite involved sampling ground water beneath and downgradient of the Seam Master property. In October 2000 a remedial investigation of the Cooper Drum site was conducted and depth-discrete ground wate r samples were collected and analyzed on the Seam Master prope rty (Ref. 14, p. 4; Ref. 22, p. 20). Analytical results indicated that ground water beneath the Seam Master property exhibited ma ximum concentrations of TCE at 8,000 ug/l and cis-1,2-DCE at 4,900 ug/l (Ref . 22, p. 122). Background levels for Seam

Master-related VOC hazardous subs tances were established based on the analytical results from ground water collected from borings CPT-16 and CPT-20. Boring CPT-16 was located northwest of the Seam Master pr operty adjacent south to the ELG Metals bui lding, upgradient of the Seam Master property production warehouse a nd raw material storag e and downgradient of the Copper Drum and Jervis prope rties. Boring CPT-20 was loca ted in the northeast portion of the Seam Master property, upgradient of the Seam Master production warehouse and raw material storage and downgradient of ELG Metals (Ref. 22, p. 51, 68, 83).

In May 2009, all new and existing ground water monitoring wells were sampled as part of the continued investigation of the Cooper Drum site. Two of the monitoring wells samples were located directly down gradient of the Seam Master property (Ref. 17, p. 15, 68). Analytical results indicated that ground water directly down gr adient of the Seam Master property exhibited maximum concentrations of TCE at 46 ug/l an d cis-1,2-DCE at 420 ug/l (Ref. 17, p. 61, 310). Background levels for Seam Master-related VOC hazardous substances were established based on the analytical results from ground water co llected from monitoring wells MW-10 and MW14. MW-10 is located in the southwest portion of the ELG Metals property, upgradient of the Seam Master property and downgrad ient of the Cooper Drum and Je rvis properties. Monitoring

well MW-14 located north of the Seam Master property on the ELG Metals property, upgradient of the Seam Master property and downgradient of the Je rvis property (Ref. 17, p. 68, 70).September 2011 30 The increased concentrations of cis-1,2-DCE in co rrelation with the decreased concentrations of

TCE between the 2000/2002 release da ta and the 2009 release data is due to cis-1,2-DCE being a degradation product of TCE (Ref . 31, p. 1). An NOV was issued in 1986 due to the illegal storage of TCE. TCE and cis-1,2-DCE are h azardous substances associated with the onsite source (Ref. 9, p. 1; Ref. 10, p. 1).

Ground water samples collected on and downgradien t of the Seam Master property establish a release to the Gaspur aquifer (Ref. 4, p. 13; Ref. 17, p. 43, 44, 51, 52, 61, 101 – 103, 310; Ref. 22, p. 70, 122).

Interconnection between the Semi-Perched, Ga spur, Exposition, and Gage Aquifers is

established within 2 miles of Source 1 at the property as follows (Ref. 1, Section 3.0.1.2.1):

• Contamination has been documented in two monitoring wells (MW-34 and MW-35) located directly downgradient of the Seam Master facility (Ref. 17, p. 15, 38, 61, 68, 310, 311). Monitoring wells MW-34 and MW-35 ar e screened within the Gaspur Aquifer (Ref. 17, p. 38, 51; Ref. 21, p. Plate 3A and 6A; Ref. 32). This supports the evidence that the Bellflower Aquiclude and Semi-per ched Aquifer are interconnected with the underlying formations (i.e., Lakewood Forma tion) since contaminants have passed through to the lower aquifers.

• An examination of DWR Geologic Sections B- B’ and L-L’ indicates that the Gaspur Aquifer is in direct contact with the Expositi on Aquifer in the property vicinity (Ref. 21, Plates 3A, 6A, and 6E; Ref. 32, p. 2; Figures A-1 and A-2 of the HRS documentation record).

• An examination of DWR Geologic Section B- B’ indicates that the unnamed aquiclude between the Exposition and Gage Aquifers is not continuous within 2 miles of the Seam Master facility. This aquita rd is shown as pinching out approximately 1,500 feet to the

west of the property , resulting in a merging of the tw o aquifers [Ref. 1, Section 3.0.1.2.1; Ref. 21, Plates 3A and 6A (Geologic Section B-B’); Ref. 32, p. 2; Figures A-1 and A-2 of the HRS documentation record].

The Seam Master property is located in an ur ban area, in which numerous drinking water wells are located (Ref. 3; Ref. 14; Ref. 18; Ref. 19; Ref. 25; Ref. 32, p. 2; Figure A-1 of the HRS documentation record). Eight drinking water wells screened within the Gage and Exposition Aquifers are located within 4 miles of Source 1 (Ref. 13, p. 2; Ref. 18; Ref. 19; Ref. 21, Plate 3A; Ref. 23; Ref. 25; Ref. 32, p. 2; Secti on 3.3.2.4 and Figure A-4 of the HRS documentation record).

An observed release to the aquifer has been doc umented in ground water samples collected at the

Seam Master Industries site. Hazardous 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 observ ed release by chemical analysis is 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 ba sed on chemical analysis (see above tables in

Section 3.1.1 of the HRS doc umentation record).

The evidence provided in this section of the HR S documentation record for the Seam Master site

documents that an observed rel ease has occurred by chemical an alysis of ground water samplesSeptember 2011 31 to the Semi-Perched/Gaspur/Exposition/Gage inte rconnected aquifer of the hazardous substances listed below (Ref. 1, Sections 2.3 and 3.1.1).

Hazardous Substances Released

TCE and cis-1,2-DCE

Ground Water Observed Release Factor Value: 550September 2011 32 3.1.2 POTENTIAL TO RELEASE

Potential to Release was not scored, becau se an Observed Release was established.September 2011 33 3.2 WASTE CHARACTERISTICS

3.2.1 TOXICITY/MOBILITY

Hazardous

Substance Source

No. Toxicity

Factor

Value

(Ref. 1,

Section 3.2.1.1) Mobility

Factor

Value* Does

Hazardous

Substance

Meet

Observed Release? (Y/N) Toxicity/ Mobility Factor Values (Ref. 1, Section 3.2.1.3,

Table 3-9) Reference

TCE 1 10,000 1 Y 10,000 Ref. 12, p. 1

cis-1,2-DCE 1 100 1 Y 100 Ref. 2, p. 5

* Hazardous substances meeting the criteria for an observed release by chemical analysis receive a mobility factor value of 1 (Ref. 1, Section 3.2.1.2).

Toxicity/Mobility Factor Value: 10,000 (Ref. 1, Section 3.2.1.3, Table 3-9)

Notes:

Y: Yes

N: NoSeptember 2011 34 3.2.2 HAZARDOUS WASTE QUANTITY

Source No. Source Type Source Hazardous Waste Quantity

1 Contaminated Soil >0

sum: >0

The hazardous waste quantity assigned from S ection 2.4.2 of the HRS documentation record for Source 1 is unknown, but greater than 0. The hazar dous waste quantity factor value assigned for the ground water pathway is 10 (Ref. 1, Sections 2.4.2.2 and 3.2.2, Table 2-6).

Hazardous Waste Quantity Factor Value: 10

3.2.3 WASTE CHARACTERISTICS FACTOR CATEGORY VALUE

Toxicity/Mobility Factor Value: 10,000 Hazardous Waste Quantity Factor Value: 10

Toxicity/Mobility Factor Value X Hazardous Waste Quantity Factor Value: 100,000

Waste Characteristics Factor Category Va lue (subject to a maximum of 100): 18 (Ref. 1, Sections 2.4.3.1 and 3.2.3, Table 2-7)September 2011 35 3.3 TARGETS

The Seam Master Industries property is locate d in an urban area, in which numerous drinking water wells are located (Ref. 13; Ref. 18; Ref. 19; Ref. 25; Figures A-1 and A-4 of the HRS documentation record). Ground water contamina tion within the Gaspur aquifer has been identified beneath the Seam Master property (R ef. 4, p. 13, 14; Ref. 17, p. 43, 44, 51, 52; Ref. 22, p. 70). Eight drinking water wells screened within the Gage and Exposition aquifers are

located within 4 miles of the source at the site (Ref. 13, p. 2; Re f. 18; Ref. 19; Ref. 21, Plate 3A; Ref. 25; Ref. 23; Sections 3.3.2.4 and Figure A-4 of the HRS documentation record). These wells were evaluated for potential contaminatio n. Interconnections between the Semi-perched, Gaspur, Exposition, and Gage aquifers is establishe d within 2 miles of the source at the site and therefore are eligible to be scored as one interconnected aq uifer (Ref. 1, Section 3.0.1.2.1; Ref. 21, Plates 3A, 6A, and 6E; Section 3.0.1, Figur es A-1 and A-2 of the HRS documentation record).

3.3.1 NEAREST WELL

Well ID: City of South Gate Well 24. This well is located 0.32 mile northeast of Source 1 at the site (Ref. 13, p. 1, 2; Figure A-4 of the HRS doc umentation record). Examination of DWR Plate 3A indicated that City of Sout h Gate Well 24 is located nearest to transect line L-L’-L”, approximately 0.15 mile from Well A5 and 0.25 m ile from Well B3 (Ref. 21, Plate 3A; Ref. 13; Ref. 32, p. 2). Examination of DWR geological s ection L-L’-L” indicates that the tip of the Gage Aquifer occurs at approxi mately 300 feet bgs and the botto m occurs at approximately 350 feet bgs in the vicinity of We lls 3S/12W-6A5 and 3S/12W-6B3 (Ref. 21, Plate 6E). The first perforation for City of South Gate Well 24 occurs at 310 feet bgs (Ref. 13). City of South Gate Well 24 is screened in the Gage Aquifer.

Level of Contamination (I, II, or potential): Potential. Sampling data are not available for this

well so Level I or II actual c ontamination cannot be documented.

Nearest Well Factor Value: 18 (Ref. 1, Table 3-11)

3.3.2 POPULATION

Within a 4-mile radius of the site source, there ar e at least eight drinking water wells that serve a total population of approximately 62,256 people. Th e wells located within the 4-mile radius encompass municipal drinking water wells (Ref . 1, Sections 3.0.1.1 and 3.3.2; Ref. 13; Ref. 18; Ref. 19; Ref. 25; Figure A-4 of the HRS documentation record).September 2011 36 3.3.2.1 Level of Contamination

3.3.2.2 Level I Concentrations

Level I Concentrations are not assigned.

Level I Concentrations Factor Value: 0

3.3.2.3 Level II Concentrations

Level II Concentrations are not assigned.

Level II Concentrations Factor Value: 0September 2011 37 3.3.2.4 Potential Contamination

Four municipalities that have publ ic water systems located within 4 miles of the sources at the site were evaluated (Figure A-4 of the HRS documentation record; Ref. 1, Section 3.3.2). The four municipalities are the City of South Gate, Walnut Park Mutual Water Company, Maywood Mutual Water Company #3, and City of Lynwood. Each municipality’s wa ter supply system is

described below.

City of South Gate The City of South Gate operates a drinking water system that serves approximately 96,375 people. Currently, the City of South Gate obtai ns all of its drinking water from ground water. The blended system consists of seven activ e drinking water wells (Wells 14, 19, 24, 25, 26, 27 and 28), four stand-by wells (Wells 14, 19, 22B, 23) , and most recently one destroyed (Well 7). No single well provides more than 40 percent of the total demand at any given time. Wells 14 and 19 provide 30 percent of th e demand, Wells 24 and 25 provi de 20 percent of the demand, Well 26 provides 20 percent of the demand, Well 27 provides 10 percent of the demand, and Well 28 provides 20 percent of the demand. The City of South Gate does not sell or purchase water to other water systems and/or water user s. In 2002, water quality sampling detected TCE in standby Well 7 at a concentration of 10.5 parts per million (Ref. 13).

Examination of DWR Plate 3A indicated that City of South Gate Well 24 is located nearest to transect line L-L’-L”, approximately 0.15 mile from Well A5 and 0.25 mile from Well B3 (Ref. 21, Plate 3A; Ref. 13; Ref. 32, p. 2). Examinati on of DWR geological sec tion L-L’-L” indicates that the tip of the Gage Aquifer occurs at ap proximately 300 feet bgs and the bottom occurs at approximately 350 feet bgs in the vicinity of Wells 3S/12W-6A5 and 3S/12W-6B3 (Ref. 21, Plate 6E). The first perforation for City of Sout h Gate Well 24 occurs at 310 feet bgs (Ref. 13). City of South Gate Well 24 is scr eened in the Gage Aquifer.

Calculation: 96,375 people/7 wells = 13,767.85 people per well

Walnut Park Mutual Water Company
The Walnut Park Mutual Water Company oper ates a drinking water system that serves approximately 17,000 people. The system consists of two active drinking water wells, Well 10 and Well 11, and one standby well, Well 12. Cu rrently, Well 12 is non- operational and not contributing any water to the system. Walnut Park Mutual Water Company does not sell or purchase water from any other water purveyors. All of the water distributed by Walnut Park Mutual Water Company is from ground water. Wa ter from the two wells is blended evenly prior to distribution (Ref. 18).

Examination of DWR Plate 3A indicated that Wa lnut Park Mutual Water Company Wells 10 and

11 are located nearest to transect line K-K’-K”, approximately 0.25 mile from Wells P2 and B1 (Ref. 3; Ref. 18; Ref. 21, Plat e 3A; Ref. 32, p. 2; Figure A-1 of the HRS documentation record). Examination of DWR geologic section K-K’-K” indi cates that the tip of the Exposition Aquifer occurs at approximately 150 feet bgs and the bottom occurs at approximately 250 feet bgs in the vicinity of Wells 2S/13W-22P2 and 2S/13W-27B11 (Ref. 21, Plate 6E). The first perforationsSeptember 2011 38 for Walnut Park Mutual Water Company Wells 10 and 11 occur at 205 feet bgs and 203 feet bgs, respectively (Ref. 18). Wells 10 and 11 are screened in the Exposition aquifer.

Calculation: 17,000 people/2 we lls = 8,500 people per well

Maywood Mutual Water Company #3
The Maywood Mutual Water Company #3 operates a drinking water supply system that contains three active drinking water wells (Prospect #1, District #4, and Ware house #7) that serve approximately 9,500 people. The Maywood Mutu al Water Company #3 obtains all of its drinking water from ground water. The Prospect #1 well contribu tes 22.7 percent to the system, the District #4 well contributes 34.9 percen t to the system, and the Warehouse #7 well contributes 42.4 percent to the system. Th e Maywood Mutual Water Company #3 does not purchase or sell their water to any other water pur veyors. All three wells are screened in the Exposition Aquifer (Ref. 19).

Well Name Gallons Per Minute (gpm) Percentage of Supply Associated Population Reference

Prospect #1 400 22.7 9,500 * 0.227 = 2,156.5 Ref. 19

District #4 1,300 34.9 9,500 * 0.349 = 3,315.5 Ref. 19

Warehouse #7 1,000 42.4 9,500 * 0.424 = 4,028 Ref. 19

City of Lynwood
The City of Lynwood operates a dr inking water supply system that contains five active drinking water wells (Wells 5, 8, 9, 11, and 19) that serv e approximately 65,965 people. Currently, all of the water is obtained from ground water, however approximately one to tw o percent of the water distributed is purchased from the Municipal Water District, on an as needed basis. No one well supplies more than 40 percent to the entire system. Well 5 contributes 9.73 percent to the system, Well 8 contributes 19.47 percent to the system, Well 9 contributes 21.24 percent to the system, Well 11 contributes 14.16 percent to the system, and Well 19 contri butes 35.4 percent to the system (Ref. 25).

Examination of DWR Plate 3A indicated that City of Lynwood Well 8 is located nearest to transect line C-C’-C”, approxima tely 0.75 mile from Well Q1 (Ref . 21, Plate 3A; Ref. 25; Ref. 32, p. 2). Examination of DWR geologic section C- C’-C” indicates that th e tip of the Exposition Aquifer occurs at approximately 175 feet bgs a nd the bottom occurs at approximately 260 feet bgs in the vicinity of Well 3S/ 13W-12Q1 (Ref. 21, Plate 6B). Pe rforations for City of Lynwood Well 8 occur at 161 to 175 feet bgs, 207 to 216 f eet bgs, and 241 to 247 feet bgs (Ref. 25). Well 8 is screened in the Exposition Aquifer.

Examination of DWR Plate 3A i ndicated that City of Lynwood We ll 19 is located nearest to transect line K-K’-K”, approximately 1 mile from Well H1 and adjacent to the C-C’-C” transect line (Ref. 21, Plate 3A; Ref. 25; Ref. 32, p. 2). Examination of DWR ge ologic section K-K’-K” indicates that the tip of the Ga ge aquifer occurs at approximately 250 feet bgs and the bottom occurs at approximately 300 feet bgs in the vici nity of Well 3S/13W-15H1 (Ref. 21, Plate 6E).September 2011 39 The City of Lynwood Well 19 is screened from 250 to 878 feet bgs (Ref. 25). Well 19 is screened in the Gage Aquifer.

Calculation: 65,965 people/6= 10,994.16 people per well/water source

Distance-Weighted Population Values

Distance Category

(miles) Public and Private Wells (Figure A-4 of the HRS documentation record) Population

Served Reference Distance-Weighted Population Value

(Ref. 1, Section 3.3.2.4, Table 3-12)

0 to -1/4 Total 0 0

> 1/4 to 1⁄2 Total 13,767.85 10,122 City of South Gate Well 24 13,767.85 Ref. 13

> 1⁄2 to 1 Total 0 0

> 1 to 2 Total 10,994.16 2,939 City of Lynwood Well 8 10,994.16 Ref. 25

> 2 to 3 Total 9,500 678 Maywood Mutual #3 Prospect #1 2,156.5 Ref. 19 Maywood Mutual #3 District #4 3,315.5 Ref. 19 Maywood Mutual #3 Warehouse #7 4,028 Ref. 19

> 3 to 4 Total 27,994.16 1306

Walnut Park Mutual Well 10 8,500 Ref. 18

Walnut Park Mutual Well 11 8,500 Ref. 18 City of Lynwood Well 19 10,994.16 Ref. 25

TOTAL: 15,045

Sum of Distance-Weighted Population Values: 15,045 Sum of Distance-Weighted Populatio n Values/10: 1,504.5 rounded to 1,504

Potential Contamination Factor Value: 1,504

3.3.3 RESOURCES

There is no information indicating that ground water drawn from any target well within 4 miles

of the source at the site is used for commercia l food/forage crop irriga tion, livestock watering, commercial food preparation, or co mmercial aquaculture. It is lik ely that there are municipal and/or community swimming pools within the target distance limit that may be utilizing ground water from the aquifers being evaluated. Howeve r, the evaluation of res ources would not affect

the final HRS score or the listing decision.

Resources Factor Value: 0September 2011 40 3.3.4 WELLHEAD PROTECTION AREA

The Wellhead Protection Area Fa ctor Value was not evaluate d for the Seam Master HRS

documentation record since the evaluation would not affect the final HRS site score or the listing

decision.

Wellhead Protection Area Factor Value: 0September 2011 41 

# Attachment AFigure A-1 0 0

. 5 Mile Property Location Map
Seam Master Industries
5211 Southern Avenue South Gate, California i h

Property

Location

Base Map: South Gate Quadrangle 7.5 Minute Series (Topographical), USGS 1981, National Geographic TOPO!0FeetLegendFacility BoundarySumpFormerAbove GroundStorage TanksPallet Production AreaSeam Master IndustriesProduction Warehouse

S o u t h e r n A v e n u e R

a

i l r o

a

d

A d

e

l l a A v

e

n

u

eParking LotFormerAbove GroundStorage TanksConcrete Linersfor FormerAbove GroundStorage TanksUndergroundStorage TankRaw MaterialStorageDrum StorageOffice S

h

e

dFacility Layout MapSeam Master Industries5211 Southern AvenueSouth Gate, CaliforniaFigureA-2Base Map: USA Prime Imagery, Los Angeles, Aerials Express 2009.Facility Features from: Weston Solutions, Inc.,Preliminary Assessment/Site Inspection Report, Seam Master Industries,South Gate, California, May 8, 2003.100+U+U+U+U+ U+ U+ U+ U+ U&.&.&.0 10FeetLegendFacility Boundary+UMonitoring Well+ UGrab Groundwater Sample&.CPT SampleSeam Master IndustriesProduction Warehouse

S o u t h e r n A v e n u e R

a

i l r

o

a

d

A d

e

l l a A v

e

n

u

e G r o u n d w a t e r
F l o w D i r e c t i o nCPT-20 BkgCPT-21CPT-16 BkgMW-10 BkgMW-34MW-35MW-14 BkgSM-1-GW BkgSM-7-GWSM-7-S2SM-7-S5SM-8-GWSM-6-GWSM-9-GWMW-34MW-35Historic Sample Location MapSeam Master Industries5211 Southern AvenueSouth Gate, CaliforniaFigureA-3Base 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 TechnicallMemorandum 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, 2003.0! 5

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

& <

Figure A-4 Legend

& < Drinking Water Well

! 5 Source Boundary

Facility Boundary

Well Search Radius

0.25 mile

0.5 mile

1 mile

2 miles

3 miles

4 miles 0 Mile

Walnut Park
Well 10

Well 11 Maywood Mutual #3

Warehouse #7

Maywood Mutual #3
District #4

Maywood Mutual #3 Prospect #1

City of South Gate

Well 24

Drinking Water Well Radius Map
Seam Master Industries
5211 Southern Avenue South Gate, California City of Lynwood

Well 8

City of Lynwood

Well 19

Base Map: World Street Map: 2009 ESRI, DeLorme, NAVTEQ, TomTom, USGS, Intermap, AND, ESRI Japan, METI, ESRI Hong Kong, ESRI Thailand, Procalculo Prosis.

Well Locations from: Hernandez, Ron, City of South Gate, Telephone Conversation recorded on Contact Report by Anitra B. Rice and Amanda K.C. Reilly, Weston Solutions, Inc., January 4 and June 22, 2011. Gonzalez, Martin, Walnut Park Mutual Water Company, Telephone Conversation recorded on Contact Report by Anitra B. Rice and Amanda K.C. Reilly, Weston Solutions, Inc., October 29, 2010 and June 30, 2011. Rohlf, Bob, Maywood Mutual Water Company #3, Telephone Conversation recorded on Contact Report by

A nitra B. Rice and Amanda K.C. Reilly, Weston Solutions, Inc., December 2, 2010 and August 24, 2011. Molina, Jose, City of Lynwood Public Works, Telephone Conversation recorded on Contact Report by Karen Jurist, USEPA, May 25, 2011. 1