Walton & Lonsbury Inc. HRS Documentation Record MAD001197755 September 2012 HRS DOCUMENTATION RECORD COVER SHEET Name of Site: Walton & Lonsbury Inc. EPA ID No .: MAD001197755 Contact Persons Site Investigation: Weston Solutions, Inc. (WESTON ) / (978) 552 - 2100 Superfund Technical Assessment and Response Team III (START) 3 Riverside Drive Andover, MA 01810 ( Ms. Carolyn Imbres and Mr. John F. Kelly) Documentation Record: U.S. Environmental Protection Agency (617) 918 - 1436 (EPA) Region I 5 Post Office Square, Suite 100 B oston, MA 02109 - 3912 (Ms. Nancy Smith) Pathways, Components, or Threats Not Scored The ground water and air migration pathways , and selected portions of the surface water migration pathway, were not scored in this Hazard Ranking System ( HRS ) documentation record because the scored portion s of the surface water migration pathway and the soil exposure pathway are sufficient to qualify the site for the National Priorities List (NPL). Ground Water Migration Pathway (not scored) Previous investigations have documented a release of hazardous substances to ground water beneath and downgradient of the Walton & Lonsbury Inc. property that is at least partially attributable to source are as [23, pp. 44 , 57, 68, 69, 80 - 91; 25, pp. 28 - 32; 30, pp. 5 , 13 - 16]. B ased on the location and proximity of the surrounding drink ing water supply resources , no nearby drinking water suppl ie s are known or suspected to have been impacted by a release from sources ; therefore, this pathway has not been included in the HRS documentation record [36 ; 37 ] . However, hazardous substances have been detected in the ground water and therefore a threat may be present for the ground water migration pathway. Surface Water Mig ration Pathway ( components and threats not scored) T his HRS documentation record evaluates only selected components and threats of the surface water migration pathway. Available data indicate that hazardous substances from sources are release d along two separate in - water segments, which form two separate branches to the su rface water migration pathway and the segments join together within the T arget D istance L imit (TDL) for the Walton & Lonsbury Inc. site [ 19 , pp. 1 - 2, 6 ] . A documented release occurs via overland flow to a wetland located immediately downgradient (south) of the Walton & Lonsbury Inc. property (see the Surface Water Migration Pathway section of this HRS documentation record) , and another release occurs via ground water - t o - surface water flow at a probabl e point of entry (PPE) along B liss B rook, east of the property . F rom the wetland south of the Walton & Lonsbury Inc. property, surface water continues to flow throughWalton & Lonsbury Inc. HRS Documentation Record MAD001197755 September 2012 a piped segment , prior to discharging to Bliss Brook south of the West Street bridge [ 19, p. 2 ] . Along the second in - water segment, after ground water emerges as surface water east of the Walton & Lonsbury Inc. property, surface water flows generally south erly along Bliss Brook, and then converges with the discharge from the piped segment south of the West Street bridge [19, pp. 1 - 2; 24, p. 4 6 ; 103, p. 2] . From the confluence of these two in - water segments, surface water flow for the watershed continues downstream along B liss Brook and additional downstream surface water bodies constituting the TDL for the site (Bungay River and Ten Mile R iver, including Mechanics Pond) [ 19, pp. 1 - 2 ] . Sensitive environments (wetlands) are located along Bliss Brook both upstream of the conf luence of the two in water segments for the surface water pathway, as well as along downstream surface water bodies , including Mechanics Pond [ 103, pp. 4 - 5, 8, 10 ] . This HRS documentation record only evaluates the release of hazardous substances via overland flow to the wetland located immediately downgradient (south) of the Walton & Lonsbury Inc. property , with a PPE at the northern edge of the wetland, south of Source Nos. 1 and 2 [ 19, p. 2 - 3 ] . Th is HRS documentation record does not evaluate the remainder of the overland/flood hazardous substance migration path, downstream of this wetland. This HRS documentation record also does not evaluate potential impacts to wetlands located along Bliss Brook from a release via ground w ater - to - surf ace wate r east of the property , nor does it evaluate the remainder of the TDL for the surface water migration pathway downstream of the convergence of the two separate in - water segment branches south of the West Street bridge. T hese additional segments of the surf ace water pathway are not evaluated as part of this HRS documentation record due to the limited availability of supporting information at this time, and since evaluation of the portions of the surface water migration pathway selected for inclusion, along w ith the evaluation of the soil exposure pathway , are sufficient to qualify the site for the NPL . However, previous investigations have documented a release of hazard ous substances via ground water to - surface water, releasing at the PPE east of the Walton & Lonsbury Inc. property along Bliss Brook, which is at least partially attributable to other previously identified source areas [23, pp. 44, 47, 57, 68, 69, 80 - 91; 24, p. 4 6 ; 25, pp. 28 - 32; 30, pp. 5, 13 - 16]. Data from previous investigations indica te a potential release of hazardous substances to additional sensitive environments not evaluated in this record and located along the TDL for the surface water migration pathway . The previous investigations have documented hazardous substances in wetland sediments along these downstream surface water bodies ; in addition, a potential fishery has been noted along the downstream surface water bodies but has not b een fully documented/confirmed [23, pp. 33 - 40, 47, 69 - 70; 25, pp. 28 - 52]. Therefore, additional impacts to portions of the surface water migration pathway are suspected. Air Migration Pathway (not scored) Based on previous reports, a historical release of hazardous substances to air from the Walton & Lonsbury Inc. property has been documented [23, pp. 48, 61 ]. However, available information is limited and insufficient to document an observed release to the air migration pathway. C onsequently , the resulting air pathway score would not likely contribute significantly to the overall si te score; therefore, this pathway has not been included in the HRS documentation record. B ased on current site conditions, it is unknown if a release of hazardous substance to air is a continuing threat to nearby receptors .Walton & Lonsbury Inc. 1 HRS Documentation Rec ord MAD001197755 September 2012 HRS DOCUMENTATION RECORD N ame of Site: Walton & Lonsbury Inc. Date Prepared: September 201 2 EPA Region: I Street Address of Site*: 78 North Avenue City, County, State, Zip Code: Attleboro, Bristol County, Massachusetts (MA) , 02703 General Location in the State: Southern MA Topographic Map: U.S. Geological Survey, Attleboro , Ma ssachusetts - Rhode Island 7.5

- minute series Topo graphical Map. 1987 [11 ]. Latitude**: 41o 57' 27.3" North Longitude**: 71o 17' 49.7" West Scores Air Pathway NS Ground Water Pathway NS Soil Exposure Pathway 100 .00 Surface Water Pathway 60 .00 HRS SITE SCORE 5 8.3 0 NS = Not Scored * The street address, coordinates, and contaminant locations presented in this Hazard Ranking System ( HRS ) documentation record id entify the general area the site is loc ated. They represent one or more locations U.S. Environmental Protection Agency ( EPA ) co nsiders to be part of the site based on the screening information EPA used to evaluate the site for National Priorities List ( NPL ) listing. EPA lists natio nal priorities among the known “releases or threatened releases” of hazardous substances; thus, the focus is on the release, not pr ecisely delineated boundaries. A site is defined as where a hazardous substance has been “ deposited, stored, placed, o r otherwise come to be located.” Generally, HRS scoring and the subsequent listing of a release merely re present the initial determination that a certain area may need to be addressed under the Comprehensive Environmental Response, Compensation , and Liability Act (CERCLA). Accordingly, EPA contemplates that the preliminary description of facility boundaries at the time of scoring will be refined as more information is developed as to where the contamination has come to be located. ** The geographic coordinates of the site w ere measured from the approximate center of the source areas identified on the Walton & Lonsbury Inc. property, located at 78 North Avenue, Attleboro, Bristol County, MA [ 10 - 13; 65 ]. See Figure 2 for the location of the latit ude and longitude measurement point. Note that additional source areas have been identified at locations south and southeast of the Walton & Lonsbury Inc. property (see Figure 2).Walton & Lonsbury Inc. 2 HRS Documentation Rec ord MAD001197755 September 2012 WORKSHEET FOR COMPUTING HRS SITE SCORE S S 2 1. Ground Water Migration Pathway Score (S gw ) NS NS 2. Surface Water Overland/Flood Migration Component (from Table 4 - 1, line 30) 60 3,600 3. Soil Exposure Pathway Score (S s ) (from Table 5 - 1, line 22) 100 10,000 4. Air Migration Pathway Score (S a ) (from Table 6 - 1, line 12) NS NS 5. Total of S gw 2 + S sw 2 + S s 2 + S a 2 13,600 6. HRS Site Score Divide the value on line 5 by 4 and take the square root 58.3 0Walton & Lonsbury Inc. 3 HRS Documentation Rec ord MAD001197755 September 2012 HRS Table 4 - 1 – S urface Water Overland/Flood Migration Component Scoresheet Factor Categories and Factors Maximum Value Value Assigned Drinking Water Threat Likelihood of Release: 1. Observed Release 550 550 2. Potential to Release by Overland Flow: 2a. Containment 10 NS 2b. Runoff 25 NS 2c. Distance to Surface Water 25 NS 2d. Potential to Release by Overland Flow (lines 2a x [2b + 2c]) 500 NS 3. Potential to Release by Flood: 3a. Containment (Flood) 10 NS 3b. Flood Frequency 50 NS 3c. Potential to Release by Flood (lines 3a x 3b) 500 NS 4. Potential to Release (lines 2d + 3c, subject to a maximum of 500) 500 NS 5. Likelihood of Release (higher of lines 1 and 4) 550 550 Waste Characteristics: 6. Toxicity/Persistence (a) NS 7. Hazardous Waste Quantity (a) NS 8. Waste Characteristics 100 NS Targets: 9. Nearest Intake 50 NS 10. Population: 10a. Level I Concentrations (b) NS 10b. Level II Concentrations (b) NS 10c. Potential Contamination (b) NS 10d. Population (lines 10a + 10b + 10c) (b) NS 11. Resources 5 NS 12. Targets (lines 9 + 10d + 11) (b) NS Drinking Water Threat Score: 13. Drinking Water Threat Score ([lines 5 x 8 x 1 2]/82,500, subject to a maximum of 100) 100 NS Human Food Chain Threat Likelihood of Release: 14. Likelihood of Release (same value as line 5) 550 550 Waste Characteristics: 15. Toxicity/Persistence/Bioaccumulation ( a ) NS 16. Hazardous Waste Quantity ( a ) NS 17. Waste Characteristics 1,000 NSWalton & Lonsbury Inc. 4 HRS Documentation Reco rd MAD001197755 September 2012 HRS T able 4-1 – Surface Water Overland/Flood Migration Component Scoresheet (cont’d) Factor Categories and Factors Maximum Value Value Assigned Targets: 18. Food Chain Individual 50 NS 19. Population: 19a. Level I Concentrations ( b ) NS 19b. Level II Concentrations ( b ) NS 1 9c. Potential Human Food Chain Contamination ( b ) NS 19d. Population (lines 19a + 19b + 19c) ( b ) NS 20. Targets (lines 18 + 19d) ( b ) NS Human Food Chain Threat Score: 21. Human Food Chain Threat Score ([lines 14 x 17 x 20]/82,500, subject to a maximum of 100) 100 NS Environmental Threat Likelihood of Release: 22. Likelihood of Release (same value as line 5) 550 550 23. Ecosystem Toxicity/Persistence/Bioaccumulation (a) 5 x 10 7 24. Hazardous Waste Quantity (a) 10,000 25. Waste Characteristics 1,000 560 Targets: 26. Sensitive Environments: 26a. Level I Concentrations (b) 0 26b. Level II Concentrations (b) 25 26c. Potential Contamination (b) NS 26d. Sensitive Environments (lines 26a + 26b + 26c) (b) 25 27. Targets (value from 26d) (b) 25 Environmental Threat Score: 28. Environmental Threat Score ([lines 22 x 25 x 27]/82,500, subject to a maximum of 60) 60 60 (93.3) Surface Water Overland/Flood Migration Component Score for a Watershed 29. c Watershed Score (lines 13 + 21 + 28, subject to a maximum of 100) 100 60 Surface Water Overland/Flood Migration Component Score 30. Component Score (S of ), (highest score from line 29 for all w atersheds evaluated, subject to a maximum of 100) (c) 100 60 ( a) Maximum value applies to waste characteristics category. (b) Maximum value not applicable. (c) Do not round to nearest integer.Walton & Lonsbury Inc. 5 HRS Documentation Rec ord MAD001197755 September 2012 HRS Table 5 - 1 – Soil Exposure Pathway Scoresheet Factor Categories and Factors Maximum Value Value Assigned Resident Population Threat Likelihood of Exposure: 1. Likelihood of Exposure 550 550 Waste Characteristics: 2. Toxicity (a) 1 0 ,000 3. Hazardous Waste Quantity (a) 10 4. Waste Characteristics 100 18 Targets: 5. Resident Individual 50 50 6. Resident Population: 6a. Level I Concentrations (b) 980 6b. Level II Concentrations (b) 0 6c. Resident Population (lines 6a + 6b) (b) 980 7. Workers 15 0 8. Resources 5 0 9. Terrestrial Sensitive Environments (c) 0 10. Targets (lines 5 + 6c + 7 + 8 + 9) (b) 1,030 Resident Population Threat Score: 11. Resident Population Threat (lines 1 x 4 x 10) (b) 10,197,000 Nearby Population Threat Likelihood of Exposure: 12. Attractiveness/Accessibility 100 NS 13. Area of Contamination 100 NS 14. Likelihood of Exposure 500 NS Waste Characteristics: 15. Toxicity (a) NS 16. Hazardous Waste Quantity (a) NS 17. Waste Characteristics 100 NS Targets: 18. Nearby Individual 1 NS 19. Population Within 1 Mile (b) NS 20. Targets (lines 18 + 19) (b) NS Nearby Population Threat Score: 21. Nearby Population Threat (lines 14 x 17 x 20) (b) NS Soil Exposure Pathway Score 22. Soil Exposure Pathway Score (S s ), (lines [11 +21]/82,500, subject to a maximum of 100) (d) 100 100 (1 23 .6)Walton & Lonsbury Inc. 6 HRS Documentation Rec ord MAD001197755 September 2012 HRS Table 5 - 1 – Soil Exposure Pathway Scoresheet (cont’d) (a) Maximum value applies to waste characteristics category. (b) Maximum value not applicable. (c) No specific maximum value applies to factor. However, pathway score based solely on terrestrial sensitive environments is limited to maximum of 60. (d) Do not round to nearest integer.Walton & Lonsbury Inc. 7 HRS Documentation Rec ord MAD001197755 September 2012 ACRONYM/ABBREVIATION LIST % Percent b gs Below Ground Surface CERCLA Comprehensive Environmental Response, Compensation, and Liability Act of 1980 CERCLIS Comprehensive Environmental Response, Compensation, and Liability Information System CLP Contract Laboratory Program COC Chain of Custody cm/s Centimeters per second CRQL Contract Required Quantitation Limit DAS Delivery of Analytical Services DPW Department of Public Works EPA EPRB U.S. Environmental Protection Agency Emergency Planning and Response Branch ERRS ft 2 GIS Emergency and Rapid Response Services square feet Geographic Information System GPR Ground Penetrating Radar GPS Global Positioning System HRS Hazardous Ranking System ID Identification MA MassDEP Massachusetts Massachusetts Department of Environmental Protection MassDOT Massachusetts Department of Transportation μg/L Micrograms Per Liter mg/Kg Milligrams Per Kilogram mg/L Milligrams Per Liter NAIC NE No. North American Industry Classification Not evaluated Number NPL NS NWI National Priorities List Not scored National Wetland Inventory OSC On - Scene Coordinator PPE P robable P oint of E ntry ppb Parts Per Billion p pm Parts Per Million QAPP Quality Assurance Project Plan RCA Resource Control Associates, Inc. RCRA Resource Conservation and Recovery Act RDL Reportable Detection Limit SCDM SOW Superfund Chemical Data Matrix Scope of Work SI SR Site Investigation Site Reassessment START Superfund Technical Assessment and Response Team III TCA T richloroethane TCE Trichloroethene TDL Target Distance LimitWalton & Lonsbury Inc. 8 HRS Documentation Rec ord MAD001197755 September 2012 TPH Total Petroleum Hydrocarbons USFWS United States Fish and Wildlife Service USGS United States Geologic al Survey WESTON Weston Solutions, Inc. XRF X - Ray Fluorescence y d 3 c ubic y ards^ _ ^ _ 

### Walton & Lonsbury (W&L) Inc. Property 1-Mile Radius

Probable Point of Entry Number 1 (PPE No. 1) for Ground Water to Surface Water release

Branch of Surface Water flow - Bliss Brook Branch of Surface Water flow - wetland south of the W&L Inc. Property I-95 Interchange PPE No. 2 for overland flow to area of open water/wetland

Convergence of two branches of Surface Water flow 

# I

0 1 0.5 Miles 0 1 0.5 Kilometers



### 9 HRS Documen Sep tation Record MAD001197755 nc. tember 2012 Figure 1 11-10-0008 G. Hornok 20 January 2012 Walton & Lonsbury Inc. 78 North Avenue Attleboro, Massachusetts Property Location Map EPA Region I Superfund Technical Assessment and Response Team (START) III Contract No. EP-W-05-042 TDD Number: Created by: Created on: Modified by: Modified on: C. Imbres 14 August 2012 Walton & Lonsbury I Topos: MicroPath/USGS 2011 Quadrangle Name: Attleboro, MA Parcel Data: Provided by Attleboro, MA [Ref. 66] All other data: START data collected as part of the 2012 Site Reassessment [Ref. 18] Data Sources:

# ^ _ ^ _ Walton & Lonsbury (W&L) Inc. Property Boundary Walton Street

Staged Soil Piles Probable Point of Entry Number 1 (PPE No. 1) for GW to SW release. Approximate Area of EPA Residential Removal Action Paulette Lane Latitude/Longitude Measurement Point

PPE No. 2 for overland flow to area of open water/wetland Open Water

Branch of SW flow - Bliss Brook

West Street Segment of piped SW flow - Drainage Pipe Trunk Line Convergence of two branches of SW flow Branch of SW flow - wetland south of W&L Inc. property.

Culvert Deanville Road Ground Water (GW) to Surface Water (SW) Flow Direction North Ave.

#

#

Figure 2 11-10-0008 G. Hornok 20 January 2012 Walton & Lonsbury Inc. 78 North Avenue Attleboro, Massachusetts Overview Property Map EPA Region I Superfund Technical Assessment and Response Team (START) III Contract No. EP-W-05-042 TDD Number: Created by: Created on: Modified by: Modified on: LEGEND Drainage Pipe Ground Water (GW) Direction Surface Water Flow Direction EPA Residential Removal Area Approximate Property Boundary Staged Soil Piles Open Water EPA Mapped Wetlands PEM PFO PSS PSS/PFO

C. Imbres 14 August 2012 Walton & Lonsbury Inc. MAD001197755 HRS Documentation Record September 2012 

### 10 0 0.1 0.05 Miles Aerials: MassGIS (Massachusetts Geographic Information System) 2005 [Ref. 6] Parcel data and partial drainage line data: Provided by the City of Attleboro in 2010 and 2011 [Ref. 22; 66] Wetland data: Provided by EPA and data recorded using GPS by START in 2012 [Ref. 103] All other data: START data collected as part of 2012 Site Reassessment [Ref. 18] Data Sources: 

# INorth Avenue



### West Street 

### Deanville Road



### Contaminated Soil Source Area C Source No. 6 Contaminated Soil Source Area B Source No.5 Contaminated Soil Source Area A Source No. 4 Walton Street 

### Residential Pile Source No. 2 Piles 5, 6, 7, and 8 Source No. 1

Surface Impoundment Area Source No. 3 Pile 7 Pile 6 Pile 8

Pile 5

Figure 3 11-10-0008 B. Mace 29 March 2012 C. Imbres 14 August 2012 Walton & Lonsbury Inc. 78 North Avenue Attleboro, Massachusetts Source Areas Map EPA Region I Superfund Technical Assessment and Response Team (START) III Contract No. EP-W-05-042 TDD Number: Created by: Created on: Modified by: Modified on: Aerials: MassGIS (Massachusetts Geographic Information System) 2005 [Ref. 6] Parcel data: Provided by the City of Attleboro in 2010 [Ref. 66] All other data: START data collected as part of 2012 Site Reassessment [Ref. 9; 18; 41] Data Sources: 

## LEGEND Approximate Property Boundary Source Area

Walton & Lonsbury Inc. MAD001197755 HRS Documentation Record September 2012 11 

### 0 0.1 0.05 Miles Note: See Figures 8, 9, and 10 for a more accurate depiction of sources 4, 5, and 6. 

# IDEANVILLE ROAD ASHTON ROAD ROUNDS PLACE NORTH AVENUE PAYSON STREET

WEST STREET 

### SOURCE NO. 6 SOURCE NO. 4 P-06-SS-07

P-22-SS-01A/B P-22-SS-08 P-18-SS-04 P-14-SS-01

P-16-SS-04

P-16-SS-03 P-06-SS-08



### SOURCE NO. 5 Walton & Lonsbury Inc. Property

SO-01B 

### Residential Pile SOURCE NO. 2 Pile 5 Pile 8 Pile 6 Pile 7 

### Pile Nos. 5, 6, 7, and 8 SOURCE NO. 1

Figure 4 11-10-0008 B. Mace 16 March 2012 C. Imbres 10 August 2012 Walton & Lonsbury Inc. 78 North Avenue Attleboro, Massachusetts Overview of Background Surface Soil/Source Samples for Sources 1, 2, 4, 5, and 6 EPA Region I Superfund Technical Assessment and Response Team (START) III Contract No. EP-W-05-042 TDD Number: Created by: Created on: Modified by: Modified on: 

### LEGEND Approximate Property Boundary Approximate Source Area Piles ! ( Background Surface Soil/Source Samples 

# I

0 200 400 100 Feet

12 HRS Documentation Record September 2012 Walton & Lonsbury Inc. MAD001197755 Data Sources: Imagery: MassGIS (Massachusetts Geographic Information Systems) 2005 [Ref. 6] Parcel data: Provided by the City of Attleboro 2010 [Ref. 66] All other data: Data collected by START and ES&M (Environmental Strategies & Management) as part of 2012 Site Reassessment [Ref. 18]

### ! ! ! ! !

! ! ! ! ! ! !

SO-08 SO-10 SO-11 SO-09 SO-13 SO-12 SO-06/SO-14 SO-05 SO-07 SO-04 SO-03 SO-02 WALTON STREET NORTH AVENUE

Pile 6 Pile 7 Pile 8 Pile 5 Residential Pile

Source No. 2

Pile Nos. 5, 6, 7, and 8 Source No. 1

Figure 5 11-10-0008 B. Mace 16 February 2012 Walton & Lonsbury Inc. 78 North Avenue Attleboro, Massachusetts

Pile Sources 1 and 2 Sample Location Map EPA Region I Superfund Technical Assessment and Response Team (START) III Contract No. EP-W-05-042 TDD Number: Created by: Created on: Modified by: Modified on: Data Sources: LEGEND Source No. 1 Source No. 2 

### ! Source Sample Locations 

# I

0 170 85 Feet

C. Imbres 14 August 2012 Walton & Lonsbury Inc. MAD001197755 HRS Documentation Record September 2012 13 Note that the building depicted in the aerial photograph was demolished as part of an EPA Removal Action and piles of excavated contaminated soils have been staged in its place.

Aerials: MassGIS (Massachusetts Geographic Information Systems) 2005 [Ref. 6] All other data: START data collected as part of the 2012 Site Reassessment [Ref. 18]Culvert 

# I

LEGEND Approximate Property Boundary Source Area Drainage Pipe Data Sources: Aerials: MassGIS (Massachusetts Geographic Information Systems) 2005 [Ref. 6] Source Area: Based on Nationwide Environmental Title Research, LLC (NETR) Aerial,1961 [Ref. 90] Parcel data and partial drainage line data: Provided by the City of Attleboro in 2010 and 2011 [Ref. 22; 66] All other data: START data collected as part of the 2012 Site Reassessment [Ref. 18]

HRS Documen Sep tation Record Figure 6 Walton & Lonsbury Inc. 78 North Avenue Attleboro, Massachusetts Surface Impoundment Source 3 Map Area
Walton & Lonsbury Inc. MAD001197755 11-10-0008 G. Hornok 20 January 2012 EPA Region I Superfund Technical Assessment and Response Team (START) III Contract No. EP-W-05-042 TDD Number: Created by: Created on: Modified by: C. Imbres Modified on: 14 August 2012 14 tember 2012 Walton & Lonsbury Inc. Property Boundary North Ave.

Deanville Road Walton Street

Surface Impoundment Area Source No. 3

Culvert

0 0.04 0.08 0.02 MilesWalton Street



### " ) " )

" ) " S

" ) " ) " S " S 

# ^ _

SD-01C SD-03

SD-04B/SD-08B

SD-05A SD-06A

SD-07A
WEST STREET NORTH AVENUE SD-01D PPE No. 2 Walton & Lonsbury Inc. Property

SD-09

Aerials: MassGIS (Massachusetts Geographic Information System) 2005 [Ref. 6] Wetland data: Provided by EPA and recorded by START using GPS in 2012 [Ref. 103] Parcel data: Provided by City of Attleboro in 2010 [Ref. 66] Source No. 3: Based on Nationwide Environmental Title Research, LLC (NETR) Aerial, 1961 [Ref. 90] All other data: START data collected as part of the 2012 Site Reassessment [Ref. 18] Data Sources: LEGEND Approximate Property Boundary Surface Impoundment/Source Area Open Water 

# ^ _ PPE No. 2 EPA Mapped Wetlands 

### " S Background Samples 

### " ) Source Samples Overland Flow and Direction

ton & Lonsbury Inc. HRS Documen Sep tation Record MAD001197755 15 tember 2012 Figure 7 11-10-0008 G. Hornok 20 January 2012 Walton & Lonsbury Inc. 78 North Avenue Attleboro, Massachusetts Surface Impoundment Area Source 3 Sample Location Map EPA Region I Superfund Technical Assessment and Response Team (START) III Contract No. EP-W-05-042 TDD Number: Created by: Created on: Modified by: Modified on: C. Imbres 14 August 2012 Wal 

## 0 250125 Feet 

# I! ( ! ( ! (

! ( ! (
! ( ! ( !

( ! (

DEANVILLE ROAD NORTH AVENUE

P-04-SS-06

P-04-SS-03

P-06-SS-03
P-06-SS-02

P-09-SS-02

P-09-SS-07 P-07-SS-02/ P-30-SS-02 P-01-SS-02B

P-01-SS-03B



### SOURCE NO. 4

Figure 8 11-10-0008 B. Mace 16 March 2012 C. Imbres 14 August 2012 Walton & Lonsbury Inc. 78 North Avenue Attleboro, Massachusetts Contaminated Soil Source 4 Sample Location Map EPA Region I Superfund Technical Assessment and Response Team (START) III Contract No. EP-W-05-042 TDD Number: Created by: Created on: Modified by: Modified on: Imagery: MassGIS (Massachusetts Geographic Information Systems) 2005 [Ref. 6] Parcel data: Provided by the City of Attleboro in 2010 [Ref. 66] Wetland data: Provided by EPA and data recorded using GPS by START in 2012. [Ref. 103] All other data: START/ES&M (Environmental Strategies & Management) data collected as part of the 2012 Site Reassessment [Ref. 18] Data Sources: 

### LEGEND Wetlands/Water Cover Additional Area of Approximate Water Cover Source Area ! ( Surface Soil/Source Samples Approximate Parcel Boundaries Inferred Boundary of Source Area 

# I

0 200 100 Feet

16 HRS Documentation Record September 2012 Walton & Lonsbury Inc. MAD001197755



### Note: Inferred boundary of source area; however, wetland areas are not considered part of contaminated soil Source No. 4.! ( ! ( ! ( ! ( ! ( ! ( ! (

! (

! ( ! ( ! ( ASHTON ROAD P-03-SS-05

P-05-SS-06

P-05-SS-05

P-05-SS-04 P-17-SS-07A

P-05-SS-01

P-24-SS-04

P-20-SS-04A/ P-31-SS-04A P-20-SS-01 P-19-SS-03 P-18-SS-09 P-18-SS-08

P-18-SS-07 ROUNDS PLACE NORTH AVENUE PAYSON STREET

P-17-SS-07B ! ( ! ( 

### SOURCE NO. 5

Figure 9 11-10-0008 B. Mace 16 March 2012 C. Imbres 10 August 2012 Walton & Lonsbury Inc. 78 North Avenue Attleboro, Massachusetts Contaminated Soil Source 5 Sample Location Map EPA Region I Superfund Technical Assessment and Response Team (START) III Contract No. EP-W-05-042 TDD Number: Created by: Created on: Modified by: Modified on: Imagery: MassGIS (Massachusetts Geographic Information Systems) 2005 [Ref. 6] Parcel data: Provided by the City of Attleboro in 2010 [Ref. 66] Wetland data: Provided by EPA and data recorded using GPS by START in 2012. [Ref. 103] All other data: START/ES&M (Environmental Strategies & Management) data collected as part of 2012 Site Reassessment [Ref. 18] Data Sources: LEGEND Approximate Area of Permanent Water Body (Bliss Brook) Inferred Boundary of Source Area Wetlands Source Area ! ( Surface Soil/Source Samples Approximate Parcel Boundaries 

### 0 180 90 Feet

17 HRS Documentation Record September 2012 Walton & Lonsbury Inc. MAD001197755 Note: Inferred boundary of source area; however, wetland areas are not considered part of contaminated soil Source No. 5. 

# I! ( ! ( ! (

! ( ! (

! ( ! ( WEST STREET

P-23-SS-06

P-21-SS-03

P-21-SS-04 P-22-SS-07

P-22-SS-10A

P-22-SS-09A
P-23-SS-02 

### SOURCE NO. 6

Figure 10 11-10-0008 B. Mace 16 March 2012 C. Imbres 10 August 2012 Walton & Lonsbury Inc. 78 North Avenue Attleboro, Massachusetts Contaminated Soil Source 6 Sample Location Map EPA Region I Superfund Technical Assessment and Response Team (START) III Contract No. EP-W-05-042 TDD Number: Created by: Created on: Modified by: Modified on: Imagery: Bing Maps Aerial (Microsoft Corporation) 2010 [Ref. 5] Parcel data: Provided by the City of Attleboro in 2010 [Ref. 66] Wetland data: Provided by EPA and data recorded using GPS by START in 2012. [Ref. 103] All other data: START/ES&M (Environmental Strategies & Management) data collected as part of 2012 Site Reassessment [Ref. 18] Data Sources: LEGEND Approximate Area of Permanent Water Body (Bliss Brook) Wetlands ! ( Surface Soil Samples Approximate Parcel Boundaries Inferred Boundary of Source Area Source Area 

# I

0 100 50 Feet

18 HRS Documentation Record September 2012 Walton & Lonsbury Inc. MAD001197755

Note: Inferred boundary of source area; however, wetland areas are not considered part of contaminated soil Source No. 6.

### " ) " )

" ) " S

" ) " ) " S " S 

# ^ _

SD-01C SD-03
SD-04B/SD-08B

SD-05A

SD-06A SD-07A NORTH AVENUE SD-01D PPE No. 2 Walton Street Walton & Lonsbury Inc. Property

SD-09 Wetland Perimeter = 0.811 miles

Figure 11 11-10-0008 G. Hornok 20 January 2012 Walton & Lonsbury Inc. 78 North Avenue Attleboro, Massachusetts Sediment Sample Location Map EPA Region I Superfund Technical Assessment and Response Team (START) III Contract No. EP-W-05-042 TDD Number: Created by: Created on: Modified by: Modified on: Aerials: MassGIS (Massachusetts Geographic Information System) February 2005 [Ref. 6] Parcel data: Provided by the City of Attleboro in 2010 [Ref. 66] Wetland data: Provided by EPA and data recorded using GPS by START in 2012 [Ref. 103] All other data: START data collected as part of the 2012 Site Reassessment [Ref. 18] Data Sources: 

# I

C. Imbres 14 August 2012 

### 0 500 250 Feet

HRS Documentation Record September 2012 Walton & Lonsbury Inc. MAD001197755 19 

### LEGEND 

# ^ _ PPE No. 2 

### " S Background Samples 

### " ) Sediment Samples EPA Mapped Wetlands Wetland Perimeter Open Water Approximate Property Boundary Overland Flow and DirectionNORTH AVEN NORTH AVENUE

P-04-SS-06 Distance to residence on Lot No. 225 (Map No. 59) = 48 feet

P-04-SS-03 Distance to residence on Lot No. 225 (Map No. 59) = 68 feet P-01-SS-02B Distance to residence on Lot No. 190A (Map No. 59) = 108 feet

P-01-SS-03B Distance to residence on Lot No. 190A (Map No. 59) = 115 feet

UE Eastern Edge of Source Area Distance to residence on Lot No. 228 (Map No. 59) = 64 feet

Figure 12
11-10-0008 B. Mace 16 March 2012 C. Imbres 14 August 2012 Walton & Lonsbury Inc. 78 North Avenue Attleboro, Massachusetts Area of Observed Contamination, Area A Sample Location and Distance Map (Northern Portion) EPA Region I Superfund Technical Assessment and Response Team (START) III Contract No. EP-W-05-042 TDD Number: Created by: Created on: Modified by: Modified on: Imagery: Bing maps Aerial (Microsoft Corporation) 2010 [Ref. 5] Wetland data: Provided by EPA and data recorded with GPS by START in 2012. [Ref. 103] Parcel data: Provided by the City of Attleboro in 2010 [Ref. 66] All other data: Data collected by START/ES&M (Environmental Strategies & Management), and EPA as part of the 2012 Site Reassessment [Ref. 18;103] Data Sources: 

### LEGEND Sample Distances ! ( Level 2 Samples ! ( Level 1 Samples Inferred Boundary of Area Wetlands Area of Observed Contamination Approximate Parcel Boundaries 

# I

0 200 100 Feet

HRS Document ti Walton & Lonsbury Inc. 

### Note: Inferred boundary of area of observed contamination; however, wetland areas are not considered part of this area.

Sep a on Record 20 MAD001197755 tember 2012

### SOURCE NO. 4

! ( ! (

! ( ! (

! ( DEANVILLE ROAD P-06-SS-03 Distance to residence on Lot No. 220 (Map No. 59) = 20 feet P-06-SS-02 Distance to residence on Lot No. 220 (Map No. 59) = 24 feet

P-09-SS-02 Distance to residence on Lot No. 114B (Map No. 49) = 53 feet

P-09-SS-07 Distance to residence on Lot No. 114B (Map No. 49) = 9 feet P-07-SS-02/ P-30-SS-02 Distance to residence on Lot No. 113 (Map No. 49) = 61 feet NORTH AVENUE

Figure 13
11-10-0008 B. Mace 16 March 2012 C. Imbres 14 August 2012 Walton & Lonsbury Inc. 78 North Avenue Attleboro, Massachusetts Area of Observed Contamination, Area A Sample Location and Distance Map (Southern Portion) EPA Region I Superfund Technical Assessment and Response Team (START) III Contract No. EP-W-05-042 TDD Number: Created by: Created on: Modified by: Modified on: Imagery: MassGIS (Massachusetts Geographic Information Systems) 2005 [Ref. 6] Parcel data: Provided by the City of Attleboro in 2010 [Ref. 66] Wetland data: Provided by EPA and data recorded with GPS by START in 2012. [Ref. 103] All other data: Data collected by START/ES&M (Environmental Strategies & Management), and EPA as part of the 2012 Site Reassessment [Ref. 18; 103] Data Sources: 

### LEGEND Sample Distances Wetlands Additional Area of Water Cover Areas of Impermeable Cover Inferred Boundary of Area ! ( Level 2 Samples ! ( Level 1 Samples Area of Observed Contamination Approximate Parcel Boundaries 

# I

0 200 100 Feet

HRS Document ti Walton & Lonsbury Inc. 

### Note: Inferred boundary of area of observed contamination; however, wetland areas are not considered part of this area.

Sep a on Record 21 MAD001197755 tember 2012P-14-SS-01

P-17-SS-07A 

# I

LEGEND Sample Distances Inferred Boundary of Area Approximate Area of Permanent Water Body (Bliss Brook) Wetlands ! Leve 2 Samples ( l ! Leve 1 Samples ( l Area of Observed Contamination Approximate Parcel Boundaries 

### 0 200 100 Feet Note: Inferred boundary of area of observed contamination; however, wetland areas are not considered part of this area. Imagery: MassGIS (Massachusetts Geographic Information Systems) 2005 [Ref. 6] Parcel data: Provided by the City of Attleboro in 2010 [Ref. 66] Wetland data: Provided by EPA and data recorded using GPS by START in 2012 [Ref. 103] All other data: Data collected by START/ES&M (Environmental Strategies & Management), and EPA as part of the 2012 Site Reassessment [Ref. 18] Data Sources:

t Figure 14
11-10-0008 B. Mace 16 March 2012 C. Imbres 14 August 2012 Walton & Lonsbury Inc. Area of Observed Contamination, Area B (Northern Portion) TDD Number:

78 North Avenue Attleboro, Massachusetts Sample Location and Distance Map EPA Region I Superfund Technical Assessment and Response Team (START) III Contract No. EP-W-05-042 Created by: Created on: Modified by: Modified on: Wal on & Lonsbury Inc. HRS Documen Sep tation Record 22 MAD001197755 tember 2012 P-03-SS-05 Distance to residence on Lot No. 112 (Map No. 49) = 148 feet

P-05-SS-06 Distance to residence on Lot No. 110 (Map No. 49) = 28 feet NORTH AVENUE! ( !

( ! ( ! ( ! (

! (

! ( ! ( P-05-SS-05 Distance to residence on Lot No. 109 (Map No. 49) = 43 feet

P-05-SS-04 Distance to residence on Lot No. 109 (Map No. 49) = 82 feet ROUNDS PLACE ! (

! ( P-05-SS-01 Distance to residence on Lot No. 109 (Map No. 49) = 109 feet P-17-SS-07A Distance to residence on Lot No. 94 (Map No. 49) = 115 feet

P-17-SS-07B Distance to residence on Lot No. 94 (Map No. 49) = 115 feet

Figure 15 11-10-0008 B. Mace 16 March 2012 C. Imbres 14 August 2012 Walton & Lonsbury Inc. 78 North Avenue Attleboro, Massachusetts Area of Observed Contamination, Area B Sample Location and Distance Map (Central Portion) EPA Region I Superfund Technical Assessment and Response Team (START) III Contract No. EP-W-05-042 TDD Number: Created by: Created on: Modified by: Modified on: Imagery: MassGIS (Massachusetts Geographic Information Systems) 2005 [Ref. 6] Wetland data: Porvided by EPA and data recorded using GPS by START in 2012. [Ref. 103] Parcel data: Provided by the City of Attleboro in 2010 [Ref. 66] All other data: Data collected by START/ES&M (Environmental Strategies & Management), EPA as part of the 2012 Site Reassessment [Ref. 18] Data Sources: LEGEND Sample Distances ! ( Level 2 Samples ! ( Level 1 Samples Wetlands Approximate Area of Permanent Water Body (Bliss Brook) Area of Observed Contamination Inferred Boundary of Area Approximate Parcel Boundaries 

### 0 200 100 Feet

23 Walton & Lonsbury Inc. MAD001197755 HRS Documentation Record September 2012 

### Note: Inferred boundary of area of observed contamination; however, wetland areas are not considered part of this area. Note: P-17-SS-07A and P-17-SS-07B are co-located and therefore are the same distance to the residence. 

# I

! ( P-16-SS-04

P-19-SS-03 PAYSON STREET! ( ! (

! ( ! (

! ( ! (

! ( P-24-SS-04 Distance to residence on Lot No. 95 (Map No. 49) = 49 feet

P-20-SS-04A/ P-31-SS-04A Distance to residence on Lot No. 97 (Map No. 49) = 173 feet P-20-SS-01 Distance to residence on Lot No. 97 (Map No. 49) = 166 feet P-19-SS-03 Distance to residence on Lot No. 97A (Map No. 49) = 102 feet P-18-SS-09 Distance to residence on Lot No. 96 (Map No. 49) = 56 feet
P-18-SS-08 Distance to residence on Lot No. 96 (Map No. 49) = 57 feet
P-18-SS-07 Distance to residence on Lot No. 96 (Map No. 49) = 64 feet ROUNDS PLACE

WEST STREET

Figure 16 11-10-0008 B. Mace 16 March 2012 C. Imbres 14 August 2012 Walton & Lonsbury Inc. 78 North Avenue Attleboro, Massachusetts Area of Observed Contamination, Area B Sample Location and Distance Map (Southern Portion) EPA Region I Superfund Technical Assessment and Response Team (START) III Contract No. EP-W-05-042 TDD Number: Created by: Created on: Modified by: Modified on: Imagery: MassGIS (Massachusetts Geographic Information Systems) 2005 [Ref. 6] Wetland data: Provided by EPA and data recorded using GPS by START in 2012. [Ref. 103] Parcel data: Provided by the City of Attleboro in 2010 [Ref. 66] All other data: Data collected by START/ES&M (Environmental Strategies & Management), and EPA as part of the 2012 Site Reassessement [Ref. 18] Data Sources: 

### LEGEND Sample Distances Approximate Area of Permanent Water Body (Bliss Brook) ! ( Level 2 Samples ! ( Level 1 Samples Inferred Boundary of Area Wetlands Areas of Impermeable Cover Area of Observed Contamination Approximate Parcel Boundaries 

### 0 200 100 Feet

24 Note: Inferred boundary of area of observered contamination; however, wetland areas are not considered part of this area.

HRS Documentation Record September 2012 Walton & Lonsbury Inc. MAD001197755 

# I! ( ! ( ! (

! ( ! (

! ( ! ( WEST STREET P-23-SS-06 Distance to residence on Lot No. 124 (Map No. 49) Building A, Apt. 1 = 20 feet Building A, Apt. 2 = 39 feet P-21-SS-03 Distance to residence on Lot No. 125 (Map No. 49) = 103 feet

P-21-SS-04 Distance to residence on Lot No. 125 (Map No. 49) = 123 feet

P-22-SS-07 Distance to residence on Lot No. 126 (Map No. 49) = 182 feet
P-22-SS-10A Distance to residence on Lot No. 126 (Map No. 49) = 174 feet P-22-SS-09A Distance to residence on Lot No. 126 (Map No. 49) = 200 feet P-23-SS-02 Distance to residence on Lot No. 124 (Map No. 49) Building B, Apt. 1 = 159 feet Building B, Apt. 2 = 135 feet Building B, Apt. 3 = 121 feet Building B, Apt. 4 = 93 feet 1 2 Building A

Building B 4 3 2 1

Figure 17 11-10-0008 B. Mace 16 March 2012 C. Imbres 14 August 2012 Walton & Lonsbury Inc. 78 North Avenue Attleboro, Massachusetts Area of Observed Contamination, Area C Sample Location and Distance Map EPA Region I Superfund Technical Assessment and Response Team (START) III Contract No. EP-W-05-042 TDD Number: Created by: Created on: Modified by: Modified on: Imagery: Bing maps Aerial (Microsoft Corporation) 2010 [Ref. 5] Wetland data: Provided by EPA and data recorded using GPS by START in 2012. [Ref. 103] Parcel data: Provided by the City of Attleboro in 2010 [Ref. 66] All other data: Collected by START/ES&M (Environmental Strategies & Management), and EPA as part of the 2012 Site Reassessment [Ref. 18] Data Sources: 

### LEGEND Sample Distances Wetlands Approximate Area of Permanent Water Body (Bliss Brook) Inferred Boundary of Area Area of Observed Contamination ! ( Level 2 Samples ! ( Level 1 Samples Approximate Parcel Boundaries 

# I

0 200 100 Feet

25 HRS Documentation Record September 2012 Note: Inferred boundary of area of observed contamination; however, wetland areas are not considered part of this area.

Walton & Lonsbury Inc. MAD001197755REFERENCES Ref. No. Des cription of the Reference [1] U.S. Environmental Protection Agency (EPA). 1990. Hazard Ranking System; Final Rule , 40 CFR Part 300, Appendix A. The complete Hazard Ranking System; Final Rule. Available from http://www.epa.gov/superfund/sites/npl/hrsres/index.htm#HRS%20Rule . 14 December. Excerpt. 96 pages. [2] U.S. Environmental Protection Agency (EPA). 2012. Superfund Chemical Data Matrix (SCDM). Available from http://www.epa.gov/superfund/sites/npl/hrsres/tools/scdm.htm . 31 March. Excerpt, Appendices BI and BII. 47 pages. [3] Reference Number Reserved. [4] Reference Number Reserved. [5] Microsoft Corporation. 2011. Bing Maps Aerial. Available from http://bing.com . Internet accessed 26 July 2012. Description available from http://www.arcgis.com . Internet accessed 13 July 2012. 3 pages. [6] MassGIS (Massachusetts Geographic Information Systems ). 2005. MassGIS Data Download - 1:5,000 Color Ortho Imagery 2005 – JPEG 2000 Format (Original), Image Number 217854. Available from http://www.mass.gov . Internet accessed 13 -August 2012. 10 pages. [7] U.S. Environmental Protection Agency (EPA). 2002 (As Amended). Comprehensive Environmental Response, Compensation, and Liability Act of 1980 “Superfund”. 31 December. 167 pages. [8] U.S. Environmental Protection Agency (EPA). 2004 (As Amended). Clean Air Act. 24 February. 465 pages. [9] Mace, B. (START). 2012. Project Note, Walton and Lonsbury, RE: Source Piles Volume Calculations. TDD No. 11-10-0008. 19 July. 8 pages. [10] City of Attleboro, Massachusetts. Tax Assessor’s Property Card for Parcel ID 89//2D. Obtained by START personnel on 6 March 2012. 2 pages. [11] USGS (U.S. Geological Survey). 1987. Attleboro Quadrangle, MA - RI (7.5 - minute series topographic map). 2 pages. [12] City of Attleboro, Massachusetts. 1965. Tax Assessor’s Property Plat No. 89. 1 January. 1 page. [13] Mace, B. (START). 2012. Project Note, Walton and Lonsbury, RE: Latitude/Longitude Calculations. TDD No. 12-01-0003. 14 February. 1 page. [14] Weston Solutions, Inc. 2010. Draft Final Removal Program Preliminary Assessment/Site Inves tigation Report for the Walton and Lonsbury Site, Attleboro, Bristol County, Massachusetts, 5 through 12 August 2010. December. 87 pages. Walton & Lonsbury Inc. 26 HRS Documentation Rec ord MAD001197755 September 2012REFERENCES Re f. No. Description of the Reference [15] U.S. Environmental Protection Agency. 2010. Memorandum from Elise I. Jakabházy, On - Scene Coordinator, Emergency Response & Removal Section I (ER&R1), EPA Region I, through David McIntyre, Chief, ER&R1, and Arthur V. Johnson III, Chief, Emergency Planning & Response Branch, EPA Region I, to James T. Owens III, Director, Office of Site Remediation and Restoration, EPA Region I, regarding Approval and Funding for a Removal Action at the Walton & Lonsbury Site, Attleboro, Bristol County, Massachusetts, Action Memorandum and Exemption from the Statutory $2,000,000 and 12
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No. Description of the Reference [50] Weston Solutions, Inc. 2012. Letter to Ms. Nancy Smith, U.S. EPA Region 1, Subject: Case No. 42162; SDG No. MA3XF7, ALS Environmental (DATAC), Walton and Lonsbury, Attleboro, Massachusetts. 23 February. 62 pages. [51] Weston Solutions, Inc. 2012. Letter to Ms. Nancy Smith, U.S. EPA Region 1, Subject: Case No. 0837F; SDG No. D31026, Mitkem Laboratories, Walton and Lonsbury, Attleboro, Massachusetts. 8 March. 77 pages. [52] Weston Solutions, Inc. 2012. Letter to Ms. Nancy Smith, U.S. EPA Region 1, Subject: Case No. 0837F; SDG No. D31008, Mitkem Laboratories, Walton and Lonsbury, Attleboro, Massachusetts. 8 March. 53 pages. [53] Weston Solutions, Inc. 2012. Letter to Ms. Nancy Smith, U.S. EPA Region 1, Subject: Case No. 42162; SDG No. MA3XN4, ALS Environmental (DATAC), Walton and Lonsbury, Attleboro, Massachusetts. 8 March. 38 pages. [54] Weston Solutions, Inc. 2012. Letter to Ms. Nancy Smith, U.S. EPA Region 1, Subject: Case No. 42162; SDG No. MA3XJ1, ALS Environmental (DATAC), Walton and Lonsbury, Attleboro, Massachuse tts. 8 March. 41 pages. [55] Reference Number Reserved. [56] Reference Number Reserved. [57] Weston Solutions, Inc. 2012. Letter to Ms. Nancy Smith, U.S. EPA Region 1, Subject: Case No. 42162; SDG No. MA3XF9, ALS Environmental (DATAC), Walton and Lonsbu ry, Attleboro, Massachusetts. 23 February. 58 pages. [58] Reference Number Reserved. [59] Weston Solutions, Inc. 2012. Letter to Ms. Nancy Smith, U.S. EPA Region 1, Subject: Case No. 0837F; SDG No. D31025, Mitkem Laboratories, Walton and Lonsbury, Attleboro, Massachusetts. 8 March. 126 pages. [60] Weston Solutions, Inc. 2012. Letter to Ms. Nancy Smith, U.S. EPA Region 1, Subject: Case No. 42162; SDG No. MA3XL9, ALS Environmental (DATAC), Walton and Lonsbury, Attleboro, Massachusetts. 5 March. 46 pages. [61] Weston Solutions, Inc. 2012. 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Walton & Lonsbury Inc. 30 HRS Documentation Rec ord MAD001197755 September 2012 [ 64] Weston Solutions, Inc. 2012. Letter to Ms. Nancy Smith, U.S. EPA Region 1, Subject: Case No. 42162; SDG No. MA3XF8, ALS Environmental (DATAC), Walton and Lonsbury, Attleboro, Massachusetts. 23 February. 61 pages. [6 5] EPA (U.S. Environmental Protection Agency). 2012. Comprehensive Environmental Response, Compensation, and Liability Information System (CERCLIS) Superfund Program, Region I, RE: Walton and Lonsbury. Printout dated 14 February. 2 pages. [66] Corresponde nce regarding Parcel Data Shapefiles for Attleboro, Massachusetts. Email from Lennox, B. City of Attleboro to Mace, B. Weston Solutions, Inc., (START). 16 November 2010. 1 page. [67] Correspondence regarding W&L – Confirmation of Onsite Soil Pile Estimates . Email from Jakabhazy, E. U.S. EPA to Kelly, J. Weston Solutions, Inc., (START). 3 April 2012. 3 pages. [68] City of Attleboro, Massachusetts. 1965. Revised 1999. 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Weston Solutions, Inc., Superfund Technical Assessment and Response Team III (START). 2012. Project Note, Walton and Lonsbury, RE: Adjusted Values for Total Metals Data, Case 42162; SDG No. MA3XJ1. TDD No. 11 -10- 0008, Task No. 0763 - 48; DC No. A - 6768. 19 March. 95 pages. [75] Reference Number Reserved. [76] Mahany, W. Weston Solutions, Inc., Superfund Technical Assessment and Response Team III (START). 2012. Project Note, Walton and Lonsbury, RE: Ad justed Values for Hexavalent Chromium Data, Case 0837F; SDG No. D31026. TDD No. 11-10-0008, Task No. 0763-48; DC No. A-6765. 23 March. 184 pages.REFERENCES Ref. No. Des cription of the Reference [77] Mahany, W. Weston Solutions, Inc., Superfund Technical Assessment and Response Team III (START). 2012. Project Note, Walton and Lonsbury, RE: Adjusted Values for Hexavalent Chromium Data, Case 0837F; SDG No. D31008. TDD No. 11 -10- 0008, Task No. 0763 - 48; DC No. A-6764. 26 March. 96 pages. [78] Reference Number Reserved. 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U.S. Environmental Protection Agency 1991 Hazardous Waste Report, Form IC. 26 February. 9 pages. [87] Mace, B. (START). 2012. Project Note, Walton and Lonsbury, RE: Downstream Distance of Sediment Samples from Probable Point of Entry. TDD No. 11-10-0008. 2 April. 2 pages. [88] Freeman Engineering Company. 1989. Figure 1 - 1, Phase II Proposed Wells, Topographical Site Plan in Attleboro, Mass, excerpted from the Phase I - Limited Site Investigation Report, prepared by Resource Control Associates, Inc., 1989. 26 January. 1 page. [89] Reference Number Reserved. [90] Nationwide Environmental Title Research, LLC (NETR). 2011. 1961 Historical Aerial of 78 North Avenue, Attleboro, Massachusetts (Source: USGS (1961-03-31 - 1961-04-27). 2 pages. [91] USGS (U.S. Geological Survey). 1943. Revised 1950. Attleboro Quadrangle, MA - RI (7.5 - minute series topographic map). Available from http://historical.m ytopo.com/getImage.asp?fname=attl50se.jpg&state=MA . 1 page. Walton & Lonsbury Inc. 31 HRS Documentation Rec ord MAD001197755 September 2012REFERENCES Ref . No. Description of the Reference [92] Mace, B. (START). 2012. Project Note, Walton and Lonsbury, RE: To determine the distance between surface soil sample locations and residences. TDD No. 11 -10-0008. 2 April. 8 pages. [93] Rizz o Associates, Inc. 1991. Phase II Site Investigation Report, 60 Walton Street, Attleboro, Massachusetts, DEP Case #4 -0764. 5 March. 75 pages. [94] CYN Environmental Services. 1997. Phase I: Initial Site Assessment Report, Former Robert’s Ford Dealershi p, 68 - 76 West Street, Attleboro, Massachusetts, MADEP Release Tracking Number: 4-12078. 16 April. 194 pages. [95] AWARD Environmental, Inc. 1997. Release Abatement Measure Plan, Kilmartin Industries, Inc., 79 Walton Street, Attleboro, Massachusetts, RTN 4-12739. 14 February. 145 pages. [96] RAM Environmental. 1997. Preliminary Assessment and Limited Site Investigation Report, Attleboro Woodworking, Inc. 1476 West Street, Route 123, Attleboro, Massachusetts. 26 June. 171 pages. [97] Environmental Science Services, Inc. 1999. Licensed Site Professional Opinion and Response Action Outcome Statement, 60 Walton Street, Attleboro, Massachusetts, RTN 4 - 14343. 14 January. 106 pages. [98] Coler & Colantonio, Inc. 1999. Immediate Response Action Completion Report, 82 North Avenue, Attleboro, Massachusetts, RTN: 4 -14492. 24 March. 117 pages. [99] Inland Professional Corporation. 2001. Release Abatement Measure Plan, 81 West Street, Attleboro, Massachusetts, RTN# 4 -16560. 3 December. 20 pages. [100] LF R, Inc. 2006. Immediate Response Action (IRA) Plan and Status Report Kilmartin Industries, 79 Walton Street, Attleboro, Massachusetts, RTN# 4 - 19739, Tier 1C Permit #W023829. 6 October. 179 pages. [101] Coneco Engineers & Scientists, Inc. 2010. Class B - 1 Response Action Outcome Statement, Massachusetts Electric Facility, 87 West Street, Attleboro, Massachusetts, Release Tracking Number 4-22265. 11 August. 259 pages. [102] MassDEP (Massachusetts Department of Environmental Protection). 2012. Searchable Waste Site List / Site Files. Available from http://public.dep.state.ma.us/SearchableSites/ . Internet accessed on 16 July 2012. 7 pages. [103] Hornok, G., Weston Solutions, Inc., (START). 2012. Memorandum, Walton and Lonsbury, RE: Wetland Delineation Memorandum. TDD No. 11-10-0008. 26 April. 33 pages. [104] EPA (U.S. Environmental Protection Agency). 2012. Comprehensive Environmental Response, Compensation, and Liability Information System (CERCLIS) Superfund Program, Region I, RE: Attleboro, MA (02703) sites. Printout dated 5 April. 2 pages. [105] EPA (U.S. Environmental Protection Agency). 2012. Resource Conservation Act Information System (RCRAInfo), RE: Attleboro, MA, sites. Printout dated 5 April. 73 pages. Walton & Lonsbury Inc. 32 HRS Documentation Rec ord MAD001197755 September 2012REFERENCES Ref. No. Description of the Reference

Walton & Lonsbury Inc. 33 HRS Documentation Rec ord MAD001197755 September 2012 [ 106] EPA (U.S. Environmental Protection Agency). 2012. Resource Conservation Act Information System (RCRAInfo), RE: Attleboro, MA, NAIC Code 332813 (Electroplating) sites. Printout dated 5 April. 4 pages. [107] ESS Laboratory, Division of Thielsch Engineering, Inc. 2011. Certificate of analysis, Client Project ID: Walton and Lonsbury. 12 May. 16 pages. [108] EPA (U.S. Environmental Protection Agency). 2012. Surf Your Watershed, RE: Narragansett Watershed - 01090004. Printout dated 14 February. 2 pages. [109] Mace, B. (START). 2012. Project Note, Walton and Lonsbury, RE: Inference of Contamination for areas between contaminated soil sample locations for Source Areas and associated Areas of Observed Contamination. TDD No. 11-10-0008. 17 July. 13 pages. [110] Correspondence regarding number of residents per address. Email from Drake, J. Hydrogeologist, MassDEP to Jakabhazy E. On - Scene Coordinator, Emergency Response & Removal Section I (ER&R1), EPA Region I, and Smith, N. U.S. EPA Region 1. 16 February 2012. 3 pages. [111] Correspondence regarding Brookside Apartments population count. Email from Zanbararo, J., Executive Director, Attleboro Housing Authority to Jakabhazy E. On-Scene Coordinator, Emergency Response & Removal Se ction I (ER&R1), EPA Region I, 15 March 2012. 2 pages. [112] Correspondence regarding Occupied Condos at 74 West Street. Email from Kutch, N. Weston Solutions, Inc., (START) to Imbres, C. Weston Solutions, Inc., (START). 6 April 2012. 2 pages. [113] Ref erence Number Reserved. [114] Reference Number Reserved. [115] Scesny, C. Weston Solutions, Inc., Superfund Technical Assistance and Response Team III (START). 2012. Project Note, Walton and Lonsbury, RE: To identify the sample nomenclature used througho ut the Walton and Lonsbury HRS documentation record. TDD No. 11-10-0008. 26 July. 3 pages. [116] MassDEP (Massachusetts Department of Environmental Protection). 2012. Searchable Waste Sites, Site Information for Site Number 4 -0010777. Available from 

### http://public.dep.state.ma.us/SearchableSites/Site_Info.asp?textfield_RTN=4 -0010777 Internet accessed on 27 July 2012. 1 page. [117] Coler & Colantonio, Inc. 2004. Response Action Outcome (RAO) Statement, Former Standard Matrix Corporation, 62 Water Street, Attleboro, Massachusetts, RTN 4-0398. 15 September. 242 pages. [118] MassDEP (Massachusetts Department of Environmental Protection). 2011. Letter fro m Daniel Crafton, Acting Chief to Courtney Wunschel, Attleboro Water Department, RE: Attleboro – BWSC, Release Tracking Number: 4 - 23324, Attleboro Water Department, 1296 West Street, Notice of Responsibility. 22 June. 3 pages.REFERENCES Ref. No. Description of the Reference

Walton & Lonsbury Inc. 34 HRS Documentation Rec ord MAD001197755 September 2012 [11 9 ] Coneco Engineers & Scientists, Incorporated . 2006. Release Notification and Class A - 2 Response Action Outcome Statement Non - PCB Mineral Oil Dielectric Fluid Release, Pol e No. 8862, Townhouse Road, Attleboro, Massachusetts, Release Tracking Number 4 - 19562. 14 March. 120 p ages.Wa lton & Lonsbury Inc. 35 HRS Documentation Record MAD001197755 September 2012 SITE SUMMARY – Walton & Lonsbury Inc. The Walton & Lonsbury Inc. site ( also referred to as the site ) consists of the release from the Walton & Lonsbury Inc. facility to the following six on - site sources (sources): two pile sources , located on the Walton & Lonsbury Inc. property and an adjacent parcel to the south ; one surface impoundment source, located within a wetland downstream (south) of the Walton & Lonsbury Inc. property; and three contaminated soil sources, located south and southeast of the Walton & Lonsbury Inc. property (see Figure 3) [see the Source Characterization sections of this HRS d ocumentation r ecord] and the contaminated surface water, wetlands, and s ediments in Bliss Brook . Of the three contaminated soil sources, one source is located south of the Walton & Lonsbury Inc. property, and east and south of the surface impoundment source and downstream wetland; and two sources are located along Bliss Brook, southeast of the Walton & Lonsbury Inc. property and downstream of a probable point of ent ry (PPE) for a ground water - to - surface water migration pathway [see the Source Characterization sections for Source Nos. 4, 5, and 6 of this HRS documentation record ]. As presented in the Source Characterization sections , these sources have been documented to contain chromium and lead . A release of chromium and lead from sources to a downstream wetland, as well as to surface soils on nearby residential properties affe cting 98 individual residents, has been documented [see Surface Water Pathway and Soil Exposure section s of this HRS documentation record ]. The Walton & Lonsbury Inc. property (also referred to as the property) is an approximately 2.8 - acre property compr ising three contiguous parcels at 78 North Avenue in Attleboro, Bristol County, MA (see Figure 1) [10 - 12]. The three parcels are identified by the City of Attleboro Tax Assessor as Map Number (No.) 89, Lot Nos. 2D, 4, and 5 [10 - 12]. The geographic coordin ates of the property, as measured from its approximate center, are 41o 57' 27.3" north latitude and 71o 17' 49.7" west longitude (see Figure 2) [13]. The property is bordered to the north by Walton Street and industrial/commercial properties; to the south by wetlands and an undeveloped property owned by the Massachusetts Department of Transportation (MassDOT) ( City of Attleboro Tax Assessor Parcel ID No . 10687) ; to the east by North Avenue and baseball fields; to the southeast by North Avenue and residential properties along Paulette Lane; and to the west by industrial/commercial properties and the Interstate 95 Interchange Access Road (I - 95) (see Figure 2) [11; 12]. The property is currently owned by Walhard Realty Trust [10 ; 14, p. 5]. Prior to demolition activities conducted during an EPA Emergency Planning and Response Branch (EPRB) Removal Action, which was initiated at the Walton & Lonsbury Inc. p roperty in September 2010, the property contained an approximately 12,0 00 - square - foot hard chromium plating facility [15, p. 1; 16, p. 4; 24, pp. 7 , 13 ] . During January and February 2012 , a t the time of sampling activities conducted during an EPA Site Reassessment (SR) of the Walton & Lonsbury Inc. site , five piles of contaminated soil associated with releases from the Walton & Lonsbury Inc. property were staged on the property and on an adjacent parcel immediately to the south , as part of the ongoing EPA Removal Action (see Figure 2) [ 18, p. 5; 67 ]. According to available documentation, c hromium electroplating operations were conducted on the Walton & Lonsbury Inc. property between 1940 and 2007 [15 , p . 2 ; 23 , pp. 5 - 6 ]. Processes conducted on the property by Walton & Lonsbury Inc. which were associated with industrial hard chromium electroplating operations included parts grinding, polishing, aqueous and solvent cleaning and degreasing, electroplating, and water rinsing [ 23, p. 6 ; 24, p. 16 - ; 83, p. 8 ]. In a 1983 Facility Annual Report submitted to the Commonwealth of Massachusetts, Walton & Lonsbury Inc. identified that “chrome sludge from plating process” was generated at a rate of 1,500 gallons a year [81, pp. 1, 7]. According to a chemical use inventory list and additional documentation included in a 1989 Phase I report prepared by Res ource Control Associates, Inc. (RCA) on behalf of Walton & Lonsbury Inc., hazardous c hemicals used at the Walton & Lonsbury Inc. proper ty included the following: chromic acid, hydrochloric acid, sulfuric acid, phosphoric acid, trichloroethylene (TCE), 1,1,1 - trichloroethane ( 1,1,1 - TCA), sodiumWa lton & Lonsbury Inc. 36 HRS Documentation Record MAD001197755 September 2012 hydro sulfite, and sodium bisulfate [24 , pp. 8 , 16 - 17 , 77 - 78 ]. A 1989 Annual Report prepared by Wa lton & Lonsbury Inc. identified the facility as a large quantity generator and on - site treatment, storage, or disposal facility generating various types of hazardous wastes including w aste hydrochloric acid and TCA, as well as “chrome plating rinse water” and “sludge” generated at a rate of 10,800 gallons per year [85, pp. 1 - 2, 5 - 10]. A 1991 Hazardous Waste Report submitted by Walton & Lonsbury Inc. to EPA identified on - site wastes generated including “corrosive chromic - acid - contaminated solid debris, from chrome - plating operation” ; “ chromic acid in water ” ; waste hydrochloric acid; “spent solvent from degreasing operation, III tricholoroethane” ; and “chromic - acid contaminated steel ductwork ventilation system for chrome - plating operation” [86, pp. 1, 3 - 7]. C orrespondence between Walton & Lonsbury Inc. and a chemical transportation company in 2007 identified that in 2007, 4,200 gallons of chromic acid solution were transported off the property for disposal and/or treatment [80, pp. 26 - 28 ]. A hazardous waste ma nifest from January 2008 documented the transport of 4,010 gallons of chromic acid from the Walton & Lonsbury Inc. property in Attleboro, MA [84]. Hazardous substances from associated sources release along two separate in - water segments, which form two s eparate branches to the hazardous substance migration path prior to the two branches joining together within the T arget D istance L imit (TDL) for the site [19, pp. 1 - 2 , 6 ; 24, p. 46 ; 28, p. 10; 103, p. 2] . One branch of surface water flow originates via ground water , which flows beneath the Walton & Lonsbury Inc. property to the east - southeast and emerges as surface water discharge at residential properties along the eastern portion of Paulette Lane and into Bliss Brook [ 23, p. 47; 2 5 , p. 32 ; 103, p. 2] . The most upstream ground water discharge to s urface water is located along the wetlands associated with the Bliss Brook headwaters [ PPE number 1 (PPE No. 1)] (see Figure 2) [19, pp. 1, 6 ] . Surface water then flows in a south erly direction within Bliss B rook , toward West Street, and beneath the West Street bridge [19, p. 1; 103, p. 2] . The second branch of the hazardous substance migration path for the site consists of overland su rface water flow to the south of the Walton & Lonsbury Inc. property toward PPE No. 2. At PPE No. 2 , surface water runoff from the property flows into an area of open water and wetlands, and continu es south toward a drainage culvert near the corner of Deanville Road and North Avenue [19, p. 2 ; 28, p. 10; 103, p. 2]. Based on observations and investigations conducted during the EPA SR , as well as information provided by City of Attleboro personnel, surface water entering the drainage culvert then flows south - southeast through piping underneath Deanville Road, to a manhole on a residential property on the southern side of Deanville Road [18, pp. 16, 25; 21; 28, p. 10]. Based on the results of field investigations , water exits this manhole via a pipe directed east - southeast, flows to the catchbasin located on an adjacent proper ty to the east, and flows farther east to a catch basin along North Avenue. Based on field observations and City of Attleboro diagrams, water then flows south along North Avenue and east along West Street through underground piping, prior to discharging to Bliss Brook immediately south of the West Street bridge [ 22, p. 2; 103 p. 2 ] . The total distance that surface water flows through underground piping, from the point at which it enters the drainage culvert near the corner of Deanville Road and North Avenue to the point where it discharges to Bliss Brook south of the West Street bridge , is approximately 1,006 feet (0.19 mile) [19 , p. 2 ; 103 p. 2 ]. Following the convergence of the two branches of in - water segments for the hazardous substance migration path , immediately south of the West Street bridge, s urface water within Bliss Brook continues to flow south until the point where Bliss Brook converges with the Bungay River ( approximately 0.40 miles downstream of PPE No. 1 ) [19, pp. 1 - 2; 103, p. 2 ]. Surface w ater subsequently flows southwest along the Bungay River for a short distance (less than 200 feet) , prior to converging with the Ten Mile River just north of the Water Street b ridge [19, p p . 1 - 2 ; 103, p. 2 ] . Surface water f low within the Ten Mile River con tinues southwest and flows through Mechanics Pond [103, p. 2] . Surface water flows south through Mechanics Pond , for a distance of approximately 0.51 miles, to the pond’s outlet [103, p. 2] . Surface water then continues to flow in a southerly direction along the Ten Mile River until the terminusWa lton & Lonsbury Inc. 37 HRS Documentation Record MAD001197755 September 2012 of the 15 - mile downstream TDL , immediately prior to the confluence with the Seekonk River in East Providence, Rhode Island [19, p p . 1 - 2 ] . Based on a 1989 report prepared by RC A , on behalf of Walton & Lonsbury Inc., untreated wastewater from chromium plating operations was discharged via a pipe directly into the wetlands located south of the facility building [24, pp. 17 - 18 , 59 ; 88 ] . According to a figure produced by RCA , on behalf of Walton & Lonsbury Inc., the pipe extended southwest from the “chrome electro plating area” within the building, and the discharge was discontinued in 1970 [24, p. 59 ; 88]. In the early 1970s, a wastewater treatment system for metals removal and pH adjustment was installed , and the pipe was reportedly “abandoned and plugged” [24, p. 18 ]. D uring excavation activities conducted in April 2011 as part of the EPA EPRB Removal Action, EPA uncovered a pipe extending southwest from the area identifi ed as the “ former chromium plating room ” toward the wetlands [16, p. 4 ; 26 , pp. 8 - 9 ]. X - Ray Fluorescence (XRF) field screening results of solid material encountered from within the pipe indicated concentrations of chromium at 157,813 milligrams per Kilogram ( mg/Kg ) , and lead at 78,876 mg/Kg [2 7 ]. According to the results of EPA’s examination of historical aerial photographs, the uncovered pipe terminated at the approximate edge of a former unnamed stream , which historically flowed south from the Walt on & Lonsbury Inc. property toward the wetland [16, p. 4]. Based on EPA’s assessment of aerial photographs, the streambed of the former unnamed stream had been enlarged and converted into a dewatering impoundment and lagoon during the 1970s [16, p. 4]. P revious investigations have identified extensive chromium and lead contamination in surface and subsurface soils located south of the Walton & Lonsbury Inc. property. D uring Phase s 3 and 4 of the EPA EPRB Site Investigation (SI) , conducted in December 2010 and April 2011, analytical results of surface and subsurface soil samples collected from the mixed - use parcels south of the Walton & Lonsbury Inc. property indicated elevated levels of chromium ( up to 56,700 mg/Kg in sample P78 - S B - 16A), hexavalent chromium ( up to 690 mg/Kg in sample P - 78 - SB - 22B), and lead ( up to 14,200 mg/Kg in sample P - 78 - SB 36B) [16, pp.7 - 8; 29, p p . 17 - 19, 40, 54, 56 ]. Du ring Phase 5 of the EPA EPRB SI , analytical results of surface and subsurface soil samples collected south of the Walton & Lonsbury Inc. property, along rear portions of residential properties along Deanville Road and North Avenue , indicated elevated levels of chromium ( up to 434,000 mg/Kg in SB - 208A), hexavalent chromium ( up to 110 mg/Kg in SB - 201B), and lead ( up to 1,100 mg/Kg in SB - 202B) [16, p. 8; 29, p p. 19 - 20, 41, 58 ]. Investigations conducted by RCA on behalf of Walton & Lonsbury Inc. have identified a dissolved chromium ground water plume associated with releases from the Walton & Lonsbury Inc. property, and have identified ground water - to - surface - water transport as an active mechanism for contaminant transport from the property to residential properties along Paulette Lane and to Bliss Brook and downstream surface water bodies [23 , pp. 44, 47, 69 - 70]. Analytical results of samples of pooled surface water and shallow ground water collected from residential properties along Paulette Lane by Walton & Lonsbury Inc.’s contractor in 2001 indicated elevated levels of chromium and hexaval ent chromium, including chromium up to 12,000 part per billion (ppb) and hexavalent chro mium up to 7,000 ppb at 37 Paulette Lane [23 , pp. 37, 95 ]. Results of further investigations of soil contamination at residential properties along Paulette Lane indicated elevated levels of metals , including lead up to 1,500 mg/Kg in sample R 01 - SB - 43, total chromium up to 67,700 mg/Kg in sample R - 02 - SB - 129, and hexavalent chromium up to 1,900 mg/Kg in sample R - 03 - SB - 159, prompting EPA to excavate contaminated soi l from several residential properties during the ongoing Removal Action [16, pp. 9 - 10; 29, pp. 15, 38 - 39, 52 ]. During Phase 2 of the EPA EPRB SI , analytical results of surf ace and subsurface soil samples collected in the residential neighborhood along Pau lette Lane and North Avenue indicated elevated levels of chromium ( up to 67,000 mg/Kg in R - 02 - SB - 129), hexavalent chromium ( up to 1,900 mg/Kg in R - 03 - SB - 159) , and lead ( up to 1,500 mg/Kg in R - 01 - SB - 43) [16, pp. 6 - 7; 29, pp. 15, 38 - 39, 52 ]. Previous investigations have identified impacts to surface water and sediments along Bliss BrookWa lton & Lonsbury Inc. 38 HRS Documentation Record MAD001197755 September 2012 associated with ground water - to - surface water contaminant release from the Walton & Lonsbury Inc. property. Analytical results of surface water samples collec ted from Bliss Brook d uring the Phase IIC investigation completed in 2001 indicated the presence of chromium [ up to 0.89 milligrams per Liter ( mg/L ) in sample S.St - 12] and hexavalent chromium (up to 0.50 mg/L in sample S.St - 4) [23, pp. 39, 92]. Analytical results of s ediment samples collected from Bliss Brook in 2001 during Phase IIC investigations indicated total chromium and hexavalent chromium concentrations of up to 2,800 mg/Kg (sample S.St - 11) a nd 2.3 mg/Kg (sample S. St - 12) , respectively [23, p. 98 ]. Surface water samples collected from Bliss Brook in November 2004 during the EPA Site Inspection contained concentrations of chromium and hexavalent chromium up to 477 ppb (SW - 06) and 440 ppb (SW - 06), respectively [25, p. 44]. Analytical sample results f rom a 2005 EPA Site Inspection revealed significantly elevated levels of chromium and hexavalent chromium at sediment sample locations at the identified PPE for ground water to - surface water release (8,140 mg/Kg chromium and 6.26 mg/Kg hexavalent chromium in SD - 03), throughout Bliss Brook ( including 6,260 mg/Kg chromium and 5.18 mg/Kg hexavalent chromium in SD 05), and downstream to the farthest down stream sediment sample location , near the southeastern outlet of Mechanics Pond (1,090 mg/Kg chromium and 2.49 mg/Kg hexavalent chromium in SD - 13) [25, pp. 36 - 37, 39, 42]. In addition , a nalytical results of surface water sampling conducted by Massachusetts Department of Environmental Pr otection ( MassDEP ) in July 2011 indicated a concentration of 30 micrograms per Liter (μg/L) of hexavalent chromium in a surface water sample collected along Bliss Brook, north of the intersection of North Avenue and W est Street [30 , pp. 3, 5, 10, 16 ].Source Characterization Source No. 1

Wa lton & Lonsbury Inc. 39 HRS Documentation Record MAD001197755 September 2012 2.2 SOURCE CHARACTERIZATION 2.2.1 SOURCE IDENTIFICATION Name of S ource : Pile s 5, 6, 7, and 8 Source Number of S ource : Source No. 1 Source Type : Pile s Description and Location of Source : The Piles 5, 6, 7, and 8 Source (Piles - Source No. 1) comprises four piles (Pile Nos. 5, 6, 7, and 8) located on portions of the Walton & Lonsbury Inc. property ( City of Attleboro, MA Tax Assessor’s Map No. 89, Lot No. 4 ) and an adjacent parcel to the south ( City of Attleboro, MA Tax Assessor’s Map No. 89 , Lot No . 3) (see Figure 5) [ 10 ; 12; 18, pp. 2 - 3; 65, p. 1; 66]. T he geographic coordinates of Source No. 1 , as measured from its approximate center, are 41° 57 ′ 26. 1 ′′ north latitude and 71° 17 ′ 49. 6 ′′ west longitude [11 ]. During Phases 1 and 3 of the EPA EPRB Removal Program SI , conducted in 2009 and 2010, Weston Solutions, Inc. (WESTON) Superfund Technical Asses sment and Response Team III ( START ) collected surface and subsurface soil sampl es from areas throughout , and just south of , the Walton & Lonsbury Inc. property [16, pp. 7, 9, 21; 29, pp. 14, 17 - 18, 37 - 38, 40, 51, 54 ]. Analytical results from the SI soil sampling events indicated elevated levels of metals, including lead up to 14,200 mg/Kg, total chromium up to 56,700 mg/Kg, and hexavalent chromium up to 690 mg/Kg [16, p. 9; 29, pp. 37 - 38, 40 ]. On 18 October 2010, EPA began a time - critical Removal Action at the Walton & Lonsbury Inc. property [ 16, p. 9 ]. On 4 March 2011, excavat ion activities were initiated in a 2 - acre area of contaminated soil d elineated during the Phase 3 SI [ 16, p. 9 ] . Exc avated soils were stockpil ed on site pending off - site disposal [ 16 , p. 9]. On 10 May 2011, EPA’s Emergency Rapid Response Services ( ERRS ) contractor collected a composite soil sample (GS - P1) from Pile No. 5 for laboratory analysis [107, pp. 1, 7 ] . A nalytical results of this sample indicated elevated levels of metals ( lead at 7 5.0 mg/Kg and total chromium at 1,170 mg/Kg ) [107, p p . 1, 7 ]. As of September 2011, approximately 2,100 tons of the stockpiled soil had been transported o ff site for disposal ; however, Pile No s . 5 , 6, 7 and 8 remained staged on the Walton & Lonsbury Inc. property and the adjacent parcel to the south [16, pp. 9 ; 18, p. 5 ]. The 2,100 tons of contaminated soil that were transported off site for disposal during the EPA Removal Action are not included in the waste quantity calculation presented in this HRS documentation record . According to information provided by the EPA On - Scene Coordinator (OSC) for the EPA EPRB Removal Action at the Walton & Lonsbury Inc. property, Pile Nos. 5, 6, 7, and 8 each consist of contaminated soil excavated from the area south of the former Walton & Lonsbury Inc. building [67] . Additional information provided by EPA indicated an estimated volume for Source No. 1 (Piles 5, 6, 7, and 8) of approximately 1,400 cubic yards ( yd 3 ), which was calculated based on observations made in the field [67]. Further volume calculations were performed for Source No. 1 based on on - site observations, as well as height measurements and perimeter area G lobal Positioning System ( GPS ) data obtained in the field [9]. Based on these estimated height measurements and perimeter area GPS data, a volume estimate of 1,173 yd 3 was calculated [9]. Therefore, a volume estimate of 1,173 yd 3 for Source No. 1 is consi dered a minimal estimate. During collection of source samples from Source No. 1, conducted as part of the 2012 EPA SR, it was observed that the so urce material constituting Pile Nos. 5, 6, 7, and 8 appeared to be generally homogeneous [18, p. 28]. During the 2012 EPA SR , each of Pile Nos. 5, 6, 7, and 8 was observed to be covered by tarps; however,Source Characterization Source No. 1

Wa lton & Lonsbury Inc. 40 HRS Documentation Record MAD001197755 September 2012 several breaches were noted in the tarp c over for each pile , and each pile lacked any maintained engineered cover [18, p. 28] . A minimal amount of tempor ary silt fencing was observed adjacent to small portions of some of the piles; however, no fully functioning run - off management system was observed and no run - on control system was noted for Pile Nos. 5, 6, 7, and 8 [18, p. 28] . Based on topography , on sit e observations, and previous reports, stormwater runoff/overland flow from the Walton & Lonsbury Inc. property flows in a southeasterly direction, toward the wetland located south of the property [11, p. 2; 18, p. 29 ; 24, p. 11 ; 25, p. 32]. Pile Nos. 5, 6, 7, and 8 meet the HRS criteria for aggregating sources and are therefore presented as one aggregate source . Each one of Pile Nos. 5, 6, 7, and 8 is a pile source type [18, p. 5] . These piles are located adj acent to and in close proximity of each other, within the same watershed and floodplain, and therefore similarly affect nearby environmental and residential population targets [9, pp. 1 - 3, 5 ; 19, pp. 1 - 3, 6 ] . As described above, each of Pile Nos. 5, 6, 7, and 8 comprises contaminated soil material exc avated from the same general area, and each pile was observed to have similar containment features [ 18, p. 28 ; 67 ] . As presented below, laboratory chemical analysis of samples collected from each of Pile Nos. 5, 6, 7, and 8 indicated the presence of similar compounds in each pile (chromium and lead). 2.2.2 HAZARDOUS SUBSTANCES ASSOCIATED WITH THE SOURCE

- Source Samples: On 25 and 26 January 2012, as part of the EPA SR and in accordance with the EPA - approved January 2012 Site - Specific Quality Assurance Project Plan (QAPP ), source sampling activities for the Piles 5, 6, 7, and 8 Source were conducted [18, pp. 5, 9 - 10 ; 28, pp. 18, 22 - 24, 62 ; 31, pp. 1, 26, 28, 33 - 35]. As part of the Piles 5, 6, 7, and 8 Source characterization, the following nine source samples were collected from various locations throughout the piles (pile number designation in parentheses): SO - 0 6, field duplicate sample SO - 14, and SO - 07 (Pile No. 5); SO - 08 and SO - 09 (Pile No. 6); SO - 10 and SO - 11 (Pile No.7); and SO - 12 and SO - 13 (Pile No. 8) [ 18, pp. 5, 9 - 10; 28, pp. 18, 22 - 24, 62 ]. All source samples collected from the Piles 5, 6, 7, and 8 Source as part of the EPA SR were collected from depths down to 2 feet below ground surface ( bgs ) [ 35, pp. 169 - 176 ]. Locations of all source samples collected from the Piles 5, 6, 7, and 8 Source are depicted in Figure 5. S ource sample SO - 06 and field duplicat e sample SO - 14 were described as dry - to - moist, brown - to - olive green, silt, some fine sand, some organics, little clay, trace medium - to - coarse sand [ 35, p. 169 ] . S ource sample SO - 07 was described as dry - to - moist, brown, silt and fine sand, little clay, little organics, trace medium - to - coarse sand, trace fine - to - medium gravel [ 35, p. 170 ] . S ource sample SO - 08 was described as dry - to - moist, brown, silt and organics, little clay, trace fine - to - coarse sand [ 35, p. 171 ] . S ource sample SO - 09 was described as d ry - to - moist, brown, silt and fine sand, some clay, trace medium - to - coarse sand, little organics, trace fine - to - medium gravel [ 35, p. 172 ] . S ource sample SO - 10 was described as dry, brown, silt, some fine sand, trace clay, trace medium - to - coarse sand, trace organics [ 35, p. 173 ] . S ource sample SO - 11 was described as dry - to - moist, brown - to - dark brown, silt, little clay, little fine - to - coarse sand, little organics [ 35, p. 174 ] . S ource sample SO - 12 was described as moist, brown, silt, little fine - to coarse sand , trace organics, trace clay, trace fine - to - medium gravel [35, p. 175] . S ource sample SO - 13 was described as dry - to - moist, brown, silt, some organics, little fine - to - coarse sand, trace clay, trace fine gravel [35, p. 176] . The nine s ource samples (SO - 06 through SO - 14) were submitted to a Contract Laboratory Program ( CLP ) l aboratory for chromium and lead analysis under CLP Scope of Work ( SOW ) ISM01.3 ; and to a Delivery of Analytical Services ( DAS ) l aboratory for hexavalent chromium analysis by EPA S W - 846 Method 7196A [18, pp. 7 - 8, 11 - 12 ; 32, p p . 1, 5, 6, 9; 50, pp. 1, 9 - 10 ; 51, pp. 1, 10 - 11 ]. Chains - of - custody (COCs) for all samples collected as part of the 2012 EPA SR and presented in this HRS documentationSource Characterization Source No. 1

Wa lton & Lonsbury Inc. 41 HRS Documentation Record MAD001197755 September 2012 record are provided in Reference 32. The a pplicable COC pages for the Source No. 1 samples , and all corresponding sample identifiers , are provided in available COC and field notes reference documentation [18, pp. 5, 7 - 12; 32, pp. 1, 5, 6, 9]. In addition, all sample IDs and associated sample numbers and COC numbers are provided in a reference table [115]. The analytical data for Source No. 1 samples were validated on a Tier II level according to EPA Region I Tiered Organic and Inorganic Data Validation Guidelines [ 50, pp. 1, 3; 51, pp. 1, 5] . I n addition, the validation was conducted independently by designated chemists who were not involved in the sample collection and HRS evaluation [ 35, p p. 169 - 173, 17 3 - 176 ; 50, pp. 1, 3; 51, pp. 1, 5 ]. Among the nine source samples collected for Source No. 1 , chromium and lead were detected at their maximum concentration s in source sample SO - 11, at 9,130 mg/Kg and 2,300 mg/Kg, respectively; and hexavalent chromium was detected at a maximum concentration of 63.7 mg/Kg in source sample SO - 08 [ 18, pp. 5, 7 - 12; 28, p. 62; 50, pp . 9, 10; 52, p. 8; 72, pp. 13 - 21, 72, 73; 76, pp. 11, 72, 73] . Based on chemical analysis of the nine source samples (SO - 06 through SO - 14) collected as part of the EPA SR , Source No. 1 has been documented to contain the hazardous substances chromium, hexavalent chromium, and lead [ 1, p. 51586; 7 , pp. 7, 14 - 15 ; 8 , pp. 52 - 56; 28, p. 62; 50, pp. 9, 10; 52, p. 8; 72, pp. 13 - 21, 72, 73; 77, pp. 11, 72, 73]. Therefore, Source No. 1 has been documented to contain hazardous substances as defined by the HRS Rule [1, p. 51586; 7 , pp. 7, 14 - 15 ; 8 , pp. 52 - 56 ]. C hromium, hexavalent chromium, and lead are considered to be associated with Source No. 1 [1, p. 51588, Section 2.2.2]. Table 1 - Hazardous Substances Associated with Source No. 1 Sample ID Sample Type Date Hazardous Substance Hazardous Substance Concentration Sample Adjusted CRQL or RDL Reference SO - 06 So urce 26 Jan. 2012 Chromium 3,300 mg/Kg 1.65 mg/Kg 18, pp. 10 - 12; 28, p. 62 ; 50, p. 10 ; 72, pp. 1, 13, 73 Lead 845 mg/Kg 1.65 mg/Kg SO - 07 Source 26 Jan. 2012 Chromium 1,450 mg/Kg 1.39 mg/Kg 18, pp. 10 - 12; 28, p. 62 ; 50, p. 9 ; 72, pp. 1, 14, 72 Lead 239 mg/Kg 1.39 mg/Kg SO - 08 Source 25 Jan. 2012 Chromium 5,000 mg/Kg 1.09 mg/Kg 18, pp. 5, 11 - 12; 28, p. 62 ; 50, p. 9 ; 72, pp. 1, 15, 72 Lead 848 mg/Kg 1.09 mg/Kg Hexavalent Chromium 63.7 mg/Kg 18.5 mg/Kg 18, pp. 5, 7 - 8; 28, p. 62 ; 52, p. 8 ; 7 7 , p p . 1 - 2, 11 , 72 SO - 09 Source 25 Jan. 2012 Chromium 1,790 mg/Kg 1.23 mg/Kg 18, pp. 5, 11 - 12; 28, p. 62 ; 50, p. 9 ; 72, pp. 1, 16, 72 Lead 437 mg/Kg 1.23 mg/Kg Hexavalent Chromium 23.6 mg/Kg 15.5 mg/Kg 18, pp. 5, 7 - 8; 28, p. 62 ; 52, p. 8 ; 7 7 , pp. 1 - 2, 11, 73 SO - 10 Source 26 Jan. 2012 Chromium 4,670 mg/Kg 1.22 mg/Kg 18, pp. 9, 11 - 12; 28, p. 62 ; 50, p. 9 ; 72, pp. 1, 17, 72 Lead 919 mg/Kg 1.22 mg/KgSource Characterization Source No. 1

Wa lton & Lonsbury Inc. 42 HRS Documentation Record MAD001197755 September 2012 Table 1 - Hazardous Substances Associated with Source No. 1 Sample ID Sample Type Date Hazardous Substance Hazardous Substance Concentration Sample Adjusted CRQL or RDL Reference S O - 11 Source 26 Jan. 2012 Chromium 9,130 mg/Kg 2.53 mg/Kg 18, pp. 9, 11 - 12; 28, p. 62 ; 50, p. 9 ; 72, pp. 1, 18, 72 Lead 2,300 mg/Kg 1.26 mg/Kg SO - 12 Source 26 Jan. 2012 Chromium 5,380 mg/Kg 1.21 mg/Kg 18, pp. 10 - 12; 28, p. 62 ; 50, p. 9 ; 72, pp. 1, 19, 72 Lead 1,380 mg/Kg 1.21 mg/Kg SO - 13 Source 26 Jan. 2012 Chromium 7,030 mg/Kg 1.57 mg/Kg 18, pp. 10 - 12; 28, p. 62 ; 50, p. 10 ; 72, pp. 1, 20, 73 Lead 1,530 mg/Kg 1.57 mg/Kg SO - 14 S ource 26 Jan. 2012 Chromium 3,340 mg/Kg 1.49 mg/Kg 18, pp. 10 - 12; 28, p. 62 ; 50, p. 10 ; 72, pp. 1, 21, 73 Lead 889.0 mg/Kg 1.49 mg/Kg Jan. = January CRQL = Contract Required Quantitation Limit RDL = Reportable Detection Limit mg/Kg = Milligrams per K ilogram List of Hazardous Substances Associated with Source Chromium Hexavalent Chromium Lead 2.2.3 HAZARDOUS SUBSTANCES AVAILABLE TO A PATHWAY On - site observations indicate that no portion of Source No. 1 has a maintained engineered cover or complete run - on or runoff control management systems [ 18 , p. 28 ]. Th erefore, Source No. 1 does not have full containment, and the source yields a containment v alue of 10 for the overland flow component of the Surface Water pathway [1, p. 51609 (Table 4 - 2)] . Table 2 - Hazardous Substances Available to Pathways Containment Description Containment Factor References Release via overland migration and/or flood : Based on the lack of a maintained engineered cover, and any complete run on and runoff control management systems, a Containment Factor Value of 10 has been assigned for release via overland migratio n and/or flood for Source No. 1. 10 1, p. 51609 (Table 4 - 2) ; 18 , p. 28 2.4.2 HAZARDOUS WASTE QUANTITY 2.4.2.1 Hazardous Waste QuantitySource Characterization Source No. 1

Wa lton & Lonsbury Inc. 43 HRS Documentation Record MAD001197755 September 2012 The Hazardous Waste Quantity for Source No. 1 was assigned based on the Volume Assigned Value of a “pile” source type [1, p. 51591, Table 2 - 5, Section 2.4.2.1.3]. The Hazardous Constituent Quantity and Hazardous Wastestream Quantity Values were not evaluated for Source No. 1 because insufficient information was available , as described in th e sections below [1, pp. 51590 - 51591 (Sections 2.4.2.1.1 and 2.4.2.1 .2 , Table 2 - 5 ) ]. 2.4.2.1.1 Hazardous Constituent Quantity Description The H azardous C onstituent Q uantity for Source No. 1 could not be adequately determined according to the HRS Rule requirements; that is, the total mass of all CERCLA hazardous substances in the source and releases from the source is not known and cannot be estimated with reasonable confidence [1, pp. 51590 - 51591 (Section 2.4.2.1.1)]. Insufficien t historical and curren t data (m anifests, PRP re cords, State records, permits , w aste concentration data, etc.) are available to adequately calculate the total mass of all CERCLA hazardous substances in the source and the associated releases from the source. Therefore, there is i nsufficient information to calculate the H azardous C onstituent Q uantity for Source No. 1 with reasonable confidence. Table 3 – Hazardous Constituent Quantity Hazardous Substance Constituent Quantity (pounds) References NS (insufficient information) Sum (pounds): Hazardous Constituent Quantity Assigned Value: NS 2.4.2.1.2 Hazardous Wastestream Quantity Description The H azardous W astestream Q uantity for Source No. 1 could not be adequately determined according to the HRS Rule requirements; that is, the total mass of all hazardous wastestreams and CERCLA pollutants and contaminants for the source and releases from the source is not known and cannot be estimated with reasonable confidence [1, p . 51591 (Section 2.4.2.1. 2 )]. Insufficien t historical and current data (m anifest s, PRP records, State records, permits, waste concentration data, a nnual reports, etc.) are available to adequately calculate the total mass of all hazardous wastestreams and CERCLA pollutants and contaminants for the source and the a ssociated releases from the source. Therefore, there is insufficient information to adequately calculate or extrapolate the H azardous W astestream Q uantity for Source No. 1 with reasonable confidence. Table 4 – Hazardous Wastestream Quantity Hazardous Waste s tream Waste s tream Quantity (pounds) References NS (insufficient information)Source Characterization Source No. 1

Wa lton & Lonsbury Inc. 44 HRS Documentation Record MAD001197755 September 2012 Sum (pounds): Sum of Waste s tream Quantity/5,000 ( 1, p. 51591, Table 2 - 5 ): Hazardous Waste s tream Quantity Assigned Value : NS 2.4.2.1.3 Volume Description An estimated volume calculation was determined for Source No. 1 based on on - site observations, as well as height measurements and perimeter area GPS data obtained in the field [9 , pp. 1 - 3, 5 ]. Based on height measurements and perimeter area GPS data obtain ed in the field, a volume estimate of 1,173 yd 3 was calculated [9, pp. 1 - 3, 5 ]. I nformation provided by EPA, which was calculated based on observations made in the field , indicated an estimated volume for Source No. 1 of approximately 1,400 yd 3 [67]. Therefore , the volume estimate of 1,173 yd 3 utilized for this HRS documentation record and presented below i s a minimal estimate. Table 5 – Volume Source

Type Description (# drums or dimensions) Units (yd 3 ) References Pile Contaminated Soil Pile 1,173 9 , p p . 1 - 3 The volume of a “ pile ” source, in yd 3 , is divided by 2.5 to assign a Hazardous Waste Quantity to the sourc e [1, p. 51591, Table 2 - 5]. Sum (yd 3 ): 1,173 Equation for Assigning Value ( 1, p. 51591, Table 2 - 5 ): 1,173 yd 3 ÷ 2.5 = 469.2 Volume Assigned Value: 469.2 2.4.2.1.4 Area Description Based on the HRS Rule, if the volume of a source can be determined, the area measure of that source should not be evaluated and the area value assigned should be zero [1, p. 51591 (Section 2.4.2.1.3] . Table 6 – Area Source Type Units (ft 2 ) References NE (Not evaluated) The area of a “ pile ” source, in ft 2 , is divided by 13 to assign a Hazardous Waste Quantity to the source [1, p. 51591, Table 2 - 5]. Equation for Assigning Value ( 1, p. 51591, Table 2 - 5):Source Characterization Source No. 1

Wa lton & Lonsbury Inc. 45 HRS Documentation Record MAD001197755 September 2012 Area Assigned Value: 0 2.4.2.1.5 Source Hazardous Waste Quantity Value The Hazardous Waste Quantity Value for Source No. 1 was assigned based on the Volume Assigned Value of 469.2 , as the highest HWQ value obtained [ 1, p. 51591, Table 2 - 5]. The Hazardous Constituent Quantity and Hazardous Wastestream Quantity Assigned Values were not evaluated for Source No. 1 because insufficient information was available [1, pp. 51590 - 51591, Sections 2.4.2.1.1, 2.4.2.1.2] . Highest HWQ value assigned from Ref. 1, Table 2 - 5: 469 .2Source Characterization Source No. 2

Wa lton & Lonsbury Inc. 46 HRS Documentation Record MAD001197755 September 2012 2.2 SOURCE CHARACTERIZATION 2.2.1 SOURCE IDENTIFICATION Name of S ource : Residential Pile Number of S ource : Source No. 2 Source Type : Pile Description and Location of Source : The Residential Pile Source (Pile - Source No. 2) is located on the central portion of the Walton & Lonsbury Inc. property , on the parcel identified on the City of Attleboro, MA Tax Assessor’s Map No. 89, as Lot No. 4 (see Figure 5) [ 10; 12; 18, pp. 2 - 3 ; 65, p.1; 66]. The geographic coordinates of the Residential Pile Source , as measured from its approximate center, are 41° 57 ′ 27.6 ′′ north latitude and 71° 17 ′ 49.7 ′′ west longitude [11 ]. Du ring Phase 2 of the EPA EPRB SI, START conducted surface and subsurface soil sampling at residential properties along Paulette Lane , east of the Walton & Lonsbury Inc. property [16, pp. 6 - 7; 29, pp. 15, 52 ]. Analytical results of soil samples indicated el evated levels of metals , including lead up to 1,500 mg/Kg, total chromium up to 67,700 mg/Kg, and hexavalent chromium up to 1,900 mg/Kg [ 16, p. 9; 29, pp. 38 - 39 ]. On 18 October 2010, EPA began a time - critical Removal Action at the Walton & Lonsbury Inc. p roperty [16, p. 9]. On 27 June 2011, EPA began excavation activities at the residential properties along Paulette Lane [16, p. 10]. Excavated soils from residential properties along Paulette Lane were stockpiled on site f or future off - site disposal [16, pp. 10, 21]. According to information provided by the EPA OSC for the EPA EPRB Removal Action at the Walton & Lonsbury Inc. property, a pile currently staged on the property, designated as the Residential Pile , consist s of contaminated soil excavated from residential properties along Paulette Lane [ 18, p. 5; 67]. Additional information provided by EPA indicated an estimated volume for Source No. 2 ( Residential Pile ) of approximately 1, 9 00 yd 3 , which was calculated based on observations made in the field [67] . Further volume calculations were performed for Source No. 2 based on on - site observations, as well as height measurements and perimeter area GPS data obtained in the field [9]. Based on these estimated height measure ments and perimeter area GPS data, a volume estimate of 2,600 yd 3 was calculated [9]. Therefore, a volume estimate of 1,900 yd 3 for Source No. 2 is considered a minimal estimate. During collection of source samples from Source No. 2 , conducted as part of the 2012 EPA SR, it was observed that the so urce material comprising the Residential Pile was generally homogeneous [18, p. 28]. During the 2012 EPA SR , the Residential Pile was observed to be covered by tarps; however, several brea ches were noted in th e tarp cover , and the pile lacked any maintained engineered cover [18, p. 28] . A minimal amount of temporary silt fencing was observed adjacent to small portions of the pile ; however, no fully functioning run - off management system was observed and no run - on control system was noted [18, p. 28] . Based on topography , on - site observations, and previous reports, stormwater runoff/overland flow from the Walton & Lonsbury Inc. property flows in a southeasterly direction, toward the wetland lo cated south of the property [11, p. 2; 18, p. 29 ; 24, p. 11 ; 25, p. 32].Source Characterization Source No. 2

Wa lton & Lonsbury Inc. 47 HRS Documentation Record MAD001197755 September 2012 2.2.2 HAZARDOUS SUBSTANCES ASSOCIATED WITH THE SOURCE

- Source Samples: On 25 and 26 January 2012, as part of the EPA SR and in accordance with the EPA - approved January 2012 Site - Specific QAPP , source sampling activities for the Residential Pile Source were conducted [18, p. 10; 28, pp. 24, 61 ; 31, pp. 1, 26, 28, 33 - 34 ]. As part of the Residential Pile Source characterization, four source samples (SO - 02, SO - 03, SO - 04, and SO - 05) were collected from variou s locations throughout the pile [ 18, p. 10; 28, pp. 24, 61 ]. All source samples collected from the Residential Pile Source as part of the EPA SR were collected from depths down to 2 feet bgs [ 35, p p. 165 - 168 ]. Locations of all source samples collected from the Residential Pile Source are depicted in Figure 5. S ource sample SO - 02 was described as moist, dark brown, silt and clay, little organics, trace fine - to coarse sand, trace fine - to - medium gravel [35, p. 165] . S ource sample SO - 03 was described as wet, dark brown, silt, some organics, trace fine - to - coarse sand, trace fine - to - medium gravel, trace clay [35, p. 166] . S ource sample SO - 04 was described as moist , dark brown - to - black, silt and organ ics, little clay, trace fine - to - coarse sand, trace fine gravel [35, p. 167] . S ource sample SO - 05 was described as dry - to - moist, dark brown - to - black, silt and organics, little clay, trace fine - to - coarse sand, trace fine - to - medium gravel [35, p. 168] . The s ource samples (SO - 0 2 through SO - 05 ) were submitted to a CLP l aboratory for chromium analysis under CLP SOW ISM01.3 [18, pp. 11 - 12 ; 32, p. 9 ; 50, pp. 1, 10 ]. COCs for all samples collected as part of the 2012 EPA SR and presented in this HRS documentation record are provided in Reference 32. The applicable COC pages for the Source No. 2 samples, and all corresponding sample identifiers, are provided in available COC and field notes reference documentation [ 18, pp. 10 - 12 ; 32, p. 9]. In addition, all sample I Ds and associated sample numbers and COC numbers are provided in a reference table [115]. The analytical data for Source No. 2 samples were validated on a Tier II level according to EPA Region I Tiered Organic and Inorganic Data Validation Guidelines [ 50, pp. 1, 5] . I n addition, the validation was conducted independently by designated chemists who were not involved in the sample collection and HRS evaluation [ 35, pp. 167 - 168; 50, pp. 1, 5 ]. Among the Source No. 2 samples, chromium was detected at a maximum concentration of 913 mg/Kg in source sample SO - 04 [18, pp. 10 - 12; 28, p. 61; 50, p. 10; 72, pp. 9

– 12, 73]. Based on chemical analysis of the four source samples (SO - 02 through SO - 05) collected as part of the EPA SR , Source No. 2 has been documen ted to contain the hazardous substance chromium [ 1, p. 51586; 7, pp. 7, 14 - 15; 8, pp. 52 - 56; 28, p. 61; 50, p. 10; 72, pp. 9 - 12, 73] . Therefore, Source No. 2 has been documented to contain a ha zardous substance as defined by the HRS Rule , and chromium is considered to be associated with Source No. 2 [1, p p . 51586 , 51588 ( Section 2.2.2 ) ; 7 , pp. 7, 14 - 15 ; 8 , pp. 52 - 56 ]. Table 7 - Hazardous Substances Associated with Source No. 2 Sample ID Sample Type Date Hazardous Substance Hazardous Substance Concentration Sample Adjusted

CRQL Reference SO - 02 Source 26 Jan. 2012 Chromium 314 mg/Kg 1.22 mg/Kg 18, pp. 10 - 12; 28, p. 61 ; 50, p. 10 ; 72, pp. 1, 9, 73Source Characterization Source No. 2

Wa lton & Lonsbury Inc. 48 HRS Documentation Record MAD001197755 September 2012 Table 7 - Hazardous Substances Associated with Source No. 2 Sample ID Sample Type Date Hazardous Substance Hazardous Substance Concentration Sample Adjusted

CRQL Reference SO - 03 So urce 26 Jan. 2012 Chromium 553 mg/Kg 1.93 mg/Kg 18, pp. 10 - 12; 28, p. 61 ; 50, p. 10 ; 72, pp. 1, 10, 73 SO - 04 So urce 26 Jan. 2012 Chromium 913 mg/Kg 1.84 mg/Kg 18, pp. 10 - 12; 28, p. 61 ; 50, p. 10 ; 72, pp. 1, 11, 73 SO - 05 So urce 26 Jan. 2012 Chromium 779 mg/Kg 1.33 mg/Kg 18, pp. 10 - 12; 28, p. 61 ; 50, p. 10 ; 72, pp. 1, 12, 73 Jan. = January CRQL = Contract Required Quantitation Limit mg/Kg = Milligrams per K ilogram List of Hazardous Substances Associated with Source Chromium 2.2.3 HAZARDOUS SUBSTANCES AVAILABLE TO A PATHWAY On - site observations indicate that no portion of Source No. 2 has a maintained engineered cover or complete run - on or runoff control management systems [ 18 , p. 28 ]. Th erefore, Source No. 2 does not have full containment, and the source yields a containment v alue of 10 for the overlan d flow component of the Surface Water Pathway [1, p. 51609 (Table 4 - 2)]. Tab le 8 - Hazardous Substances Available to Pathways Containment Description Containment Factor References Release via overland migration and/or flood : Based on the lac k of a maintained engineered cover, and any complete run on and runoff control management systems, a Containment Factor Value of 10 has been assigned for release via overland migration and/or flood for Source No. 2 . 10 1, p. 51609 (Table 4 - 2) ; 18 , p. 28Source Characterization Source No. 2

Wa lton & Lonsbury Inc. 49 HRS Documentation Record MAD001197755 September 2012 2.4.2 HAZARDOUS WASTE QUANTITY 2.4.2.1 Hazardous Waste Quantity The Hazardous Waste Quantity for Source No. 2 was assigned based on the Volume Assigned Value of a “pile” source type [1, p. 51591, Table 2 - 5, Section 2.4.2.1.3]. The Hazardous Constituent Quantity and Hazardous Wastestream Quantity Values wer e not evaluated for Source No. 2 because insufficient information was available , as described in th e sections below [1, pp. 51590 - 51591 (Sections 2.4.2.1.1 and 2.4.2.1 .2 , Table 2 - 5 ) ]. 2.4.2.1.1 Hazardous Constituent Quantity Description The H azardous C onstituent Q uantity for Source No. 2 could not be adequately determined according to the HRS Rule requirements; that is, the total mass of all CERCLA hazardous substances in the source and releases from the source is not known and cannot be estimated with reasonable confidence [1, pp. 51590 - 51591 (Section 2.4.2.1.1)]. Insufficien t historical and current data (manifests, PRP records, State records, permits, w aste concentration data, etc.) are available to adequately calculate the total mass of all CERCLA hazardous substances in the source and the associated releases from the source . Therefore, there is insufficient information to calculate the H azardous C onstituent Q uantity for Source No. 2 with reasonable confidence. Table 9 – Hazardous Constituent Quantity Hazardous Substance Constituent Quantity (pounds) References NS (insufficient information) Sum (pounds): Hazardous Constituent Quantity Assigned Value: NS 2.4.2.1.2 Hazardous Wastestream Quantity Description The H azardous W astestream Q uantity for Source No. 2 could not be adequately determined according to the HRS Rule requirements; that is, the total mass of all hazardous wastestreams and CERCLA pollutants and contaminants for the source and releases from the source is not known and cannot be estimated with r easonable confidence [1, p. 51591 (Section 2.4.2.1.2)]. Insufficien t historical and current data (m anifest s, PRP records, State records, permits, w aste concentration data, a nnual reports, etc.) are available to adequately calculate the total mass of all hazardous wastestreams and CERCLA pollutants and contaminants for the source and the associated releases from the source. Therefore, there is insufficient information to adequ ately calculate or extrapolate the H azardous W astestream Q uantity for Source No. 2 with reasonable confidence.Source Characterization Source No. 2

Wa lton & Lonsbury Inc. 50 HRS Documentation Record MAD001197755 September 2012 Table 10 – Hazardous Wastestream Quantity Hazardous Waste s tream Waste s tream Quantity (pounds) References NS (insufficient information) Sum (pounds): Sum of Waste s tream Quantity/5,000 ( 1, p. 51591, Table 2 - 5 ): Hazardous Waste s tream Quantity Assigned Value : NS 2.4.2.1.3 Volume Description The volume estimate presented for Source No. 2 is based on information provided by EPA, and was determined by calculations that were based on observations made in the field. Based on the field calculations and information provided by EPA, the volume of Source No. 2 is estimated to be 1,900 yd 3 [67]. An estimated volume calculation was also determined based on height measurements and perimeter area GPS data obtained in the field [9 , pp. 1, 3 ]. Based on height measurements and perimeter area GPS data obtained in the field , a volume estimate of 2,600 yd 3 w as calculated [9]. Therefore, the volume estimate of 1,900 yd 3 utilized for this HRS documentation record and presented below is a minimal estimate . Table 11 – Volume Source

Type Description (# drums or dimensions) Units (yd 3 ) References Pile Contaminated Soil Pile 1,900 67 The volume of a “ pile ” source, in yd 3 , is divided by 2.5 to assign a Hazardous Waste Quantity to the sourc e [1, p. 51591, Table 2 - 5]. Sum (yd 3 ): 1,900 Equation for Assigning Value ( 1, p. 51591, Table 2 - 5 ): 1,900 yd 3 ÷ 2.5 = 760 Volume Assigned Value: 760 2.4.2.1.4 Area Description Based on the HRS Rule, if the volume of a source can be determined, the area measure of that source should not be evaluated and the area value assigned should be zero [1, p. 51591 (Section 2.4.2.1.3].Source Characterization Source No. 2

Wa lton & Lonsbury Inc. 51 HRS Documentation Record MAD001197755 September 2012 Table 12 – Area Source Type Units (ft 2 ) References NE (Not Evaluated) The area of a “ pile ” source, in ft 2 , is divided by 13 to assign a Hazardous Waste Quantity to the source [1, p. 51591, Table 2 - 5]. Equation for Assigning Value ( 1, p. 51591, Table 2 - 5): Area Assigned Value: 0 2.4.2.1.5 Source Hazardous Waste Quantity Value The Hazardous Waste Quantity Value for Source No. 2 was assigned based on the Volume Assigned Value of 760 , as the highest HWQ value obtained [1, p. 51591, Table 2 - 5]. The Hazardous Constituent Quantity and Hazardous Wastestream Quantity Assigned Values were not evaluated for Source No. 2 because insufficient information was available [1, pp. 51590 - 51591, Sections 2.4.2.1.1, 2.4.2.1.2]. High est HWQ value assigned from Ref. 1, Table 2 - 5: 760Source Characterization Source No. 3

Wa lton & Lonsbury Inc. 52 HRS Documentation Record MAD001197755 September 2012 2.2 SOURCE CHARACTERIZATION 2.2.1 SOURCE IDENTIFICATION Name of Source : Surface Impoundment Area Source Number of Source : Source No. 3 Source Type : Surface Impoundment Description and Location of Source (with reference to a map of the site) : The Surface Impoundment Area Source (Surface Impoundment - Source No. 3) is located on properties south of the Walton & Lonsbury Inc. property, which are depicted on the City of Attleboro, MA Tax Assessor’s Map No. 89, as Lot No . 3 ; and on Map No. 59, as Lot Nos. 142, 190A, 220, 225, 227, and 229 (see Figure 6) [10; 12; 41; 65, p.1; 66; 68 ]. The geographic coordinates of the Surface Impo undment Area Source , as measured from its approximate center, are 41° 57 ′ 20.5 ′′ north latitude and 71° 17 ′ 51.1 ′′ west longitude [11; 41]. Based on a 1989 report prepared by RCA for Walton & Lonsbury Inc., untreated wastewater from chromium plating operations was historically discharged via a pipe directly into the wetlands located south of the Walton & Lonsbury Inc. property [24, pp. 16 - 18 , 59 ; 88]. According to a figure produced by RCA for Walton & Lonsbury Inc., the pipe extended southwest from the “chrome electro plating area” within the Walton & Lonsbury Inc. facility building, and the discharge was discontinued in 1970 [24, p. 59 ; 88]. In the early 1970s, a wastewater treatment system for metal s removal and pH adjustment was installed , and the pipe was reportedly “abandoned and plugged” [24, p. 18 ]. D uring excavation activities conducted in April 2011 as part of the EPA EPRB Removal Action, EPA uncovered a pipe extending southwest from the are a identified as the “ former chromium plating room ” toward the wetlands [ 16, p. 4; 26, pp. 8 - 9 ]. XRF field screening results of solid material encountered from within the pipe indicated concentrations of chromium at 157,813 mg/Kg, and lead at 78,876 mg/Kg [2 7 ]. According to the results of EPA’s examination of historical aerial photographs, the uncovered pipe terminated at the approximate edge of a former unnamed stream , which historically flowed south from the Walton & Lonsbury Inc. property toward the wetl and [16, p. 4]. Based on EPA’s assessment of aerial photographs, the streambed of the former unnamed stream had been enlarged and converted into a dewatering impoundment and lagoon in the 1970s [16, p. 4]. A nalytical results of samples collected in 2010 a nd 2011 as part of the EPA EPRB SI revealed extensive chromium and lead contamination throughout several acres within the wetland south of the Walton & Lonsbury Inc. property , as well as elevated levels of these elements in soils along rear portions of adj acent residential properties along Deanville Road and North Avenue [29, pp. 17 - 20, 40 - 41 , 54, 56, 58 ]. Laboratory analytical results of samples collected from these wetland areas during the EPA EPRB SI at depths less than 2 feet below the sediment/water in terface indicated elevated levels of chromium (up to 42,000 mg/Kg); hexavalent chromium (up to 110 mg/Kg); and lead ( up to 9,300 mg/Kg) [29, pp. 40 - 41 ]. A nalytical results of sediment samples collected as part of the 2012 EPA SR indicated concentrations significantly above background levels in each of the five sediment samples collected from the wetland, as presented in the sections below. Source No. 3 has been characterized by analysis of sediment samples which, based on the locations of the samples, appear to represent sediments beside or underneath the former surface impoundment (see Figures 6 and 7). These sediments became contaminated v ia runoff or deposition from former liquid waste surface impoundment material.Source Characterization Source No. 3

Wa lton & Lonsbury Inc. 53 HRS Documentation Record MAD001197755 September 2012 Aerial imagery from 1961 was utilized to determine the area of Source No. 3 (see Figure 6) [41; 90]. The 1961 aerial imagery indicates evidence of the surface impoundment sout h of the Walton & Lonsbury Inc. facility building [90]. Based on an interpretation of the 1961 aerial imagery, the historical surface impoundment consi sted of two areas of open water , and therefore no soil cover was identified within the surface impoundmen t area [41; 90]. I n addition, this area was observed to be covered by water during the 2012 EPA SR sediment sampling activities [35, pp. 185 - 186, 188, 190; 41; 90]. A trench connecting the two areas of open water is apparent in the 1961 aerial imagery, and remnants of the trench were also observed during EPA SR sediment sampling activities [41; 90]. No other information regarding the areal extent of the historical surface impoundment south of the Walton & Lonsbury Inc. property was found in available file d ocumentation. Based on a 1950 topographical map and the 1988 RCA figure, the area historically encompas sed by the surface impoundment, as determined by interpretation of the 1961 aerial imagery, consisted of generally level topography and wetland areas, similar to the conditions observed in 2012 [11, p. 2; 90; 91; 103, pp. 7 - 10]. A 1990 report by RCA indicates that at the time of the report, portions of the Walton & Lonsbury Inc. property, as well as adjacent properties to the south and west, exhibited the characteristics of a wetland; however, no formal wetland delineation was found in available documentation [17, p. 1 6 ]. Therefore, i t is unknown based on available documentation whether the historical surface impoundment included additional portions of the wetland than those areas identified via interpretation of the 1961 aerial imagery, or whether the surface impoundment historically extended to the boundaries of the wetland area as mapped by EPA in 2012 ( which encompasses 8.5 acres) [103 , pp. 10, 26]. B ased on the limited information available , only the area identified as open water via interpretation of the 1961 aerial imagery is presented as the area of Source No. 3 , although the source area could be larger [41; 90]. Based on the 1961 aerial imagery d epicting the surface impoundments areas, and areal calculations conducted using Geographic Information System ( GIS ) software, the area of Source No. 3 was determined to be 130,389 square feet ( ft 2 ) ( equivalent to 2.99 ac res ) [41]. 2.2.2 HAZARDOUS SUBSTANCES ASSOCIATED WITH THE SOURCE

- Background Concentrations: The Surface Impoundment Area Source (Source No. 3) is a surface impoundment source type. However, the surface impoundment liquid waste material is no longer present; rather, Source No. 3 sediment samples consist of contaminated sediment material from beside or underneath the former impoundment, which came to be contaminated by contaminated impoundment material. T he samples documenting the surface impoundment source contained naturally occurring native s ediment material; therefore, a comparison to background sediment samples is presented [ 18 , pp. 5 - 6, 9 ; 28 , pp. 19, 23, 63 ]. On 25 and 26 January 2012, as part of the EPA SR and in accordance with the EPA - approved January 2012 Site - Specific QAPP , background sediment sampling activities were conducted [ 18, pp. 5 - 6, 9; 28, pp. 19, 23, 63 ; 31, pp. 1, 26, 30, 36, 38 ]. Two background sediment samples (SD - 01C and SD - 01D) were collected from a n upstream tributary on an undeveloped parcel located southwest of the Walton & Lonsbury Inc. property , depicted on the City of Attleboro , MA Ta x Assessor ’s Map No. 89, as “P/O 110, t aken for Interstate 95” (see Figure 7) [10; 12; 18, pp. 5 - 6; 28, p. 19, 63 ]. In addition, one background sediment sample (SD - 03) was collected from a location immediately southwest of the Walton & Lonsbury Inc. property, from a property depicted on the City of Attleboro, MA Tax Assessor’s Map No. 59, as Lot Nos. 185 to 190 (land taken for Interstate Routes 95 and 295) [10; 12; 68]. Background sediment sample SD - 03 was collected immediately downstream of the discharge point of an outfall pipe , which emerg es from a retaining wall of the property located immediately adjacent to and west of the Walton & Lonsbury Inc. property [ 18, pp. 9; 28, pp. 23, 63 ] . Based on information provided in a previousSource Characterization Source No. 3

Wa lton & Lonsbury Inc. 54 HRS Documentation Record MAD001197755 September 2012 report, the outfall pipe discharges stormwater runoff from the industrial park area west of the Walton & Lonsbury Inc. property [ 2 4, p. 15 ]. The three background sediment samples (SD - 01C, SD - 01D, and SD - 03) were collected in the vicinity of the site from the same depth interval (0 - to 2 - feet bgs ) , during the same time period , and utilizing the same collection and analytical methods as the sediment samples presented as part of the Source No. 3 Characterization [ 18, pp. 5 - 7, 9, 11 - 12; 28, pp. 19 - 20, 23, 63 - 64; 32, p. 10; 35, pp. 179 - 180, 183, 186, 18 8; 54, p. 1; 64, p. 1 ]. The three background sediment samples collected during the 2012 EPA SR contained varying compositions of naturally occurring native matrix materials [35, pp. 179 - 180, 183]. In addition, t he background sediment samples and the sediment samples contained similar native matrix materials [ 35, pp. 179 - 180, 183, 185 - 186, 188 , 190 ]. All three background sediment samples are presented as part of this HRS documentation record, and Source No. 3 sediment samples were compared to the highe st concentrations detected among the three background sediment samples for the analytes presented. Background sediment sample SD - 01C was described as saturated, dark brown, organics and silt, trace fine - to - coarse sand, trace fine - to - medium gravel [ 35, p. 179 ]. Background sediment sample SD - 01D was described as saturated, brown - to - olive green, silt and organics, little clay, little fine - to - coarse sand, trace fine - to - medium gravel [ 35, p. 180 ] . Background sediment sample SD - 03 was described as saturated, brown - to - cinnamon brown, fine to coarse sand, little fine - to - medium gravel, trace organics, trace silt [ 35, p. 183 ] . Background s ediment sample s S D - 01 C, SD - 01D, and SD - 03 w ere submitted to a CLP l aboratory for chromium and lead analysis under CLP SOW ISM0 1.3 [ 18, pp. 11 - 12; 32, p. 10; 64, pp. 1, 9 ]. COCs for all samples collected as part of the 2012 EPA SR and presented in this HRS documentation record are provided in Reference 32. The applicable COC pages for the Source No. 3 background sediment samples , and all corresponding sample identifiers , are provided in available COC and field notes reference documentation [18, pp. 5 - 6, 9, 11 - 12; 32, p. 10]. In addition, all sample IDs and associated sample numbers and COC numbers are provided in a reference table [115]. The analytical data for Source No. 3 samples were validated on a Tier II level according to EPA Region I Tiered Organic and Inorganic Data Validation Guidelines [ 64, pp. 1, 4 ]. I n addition, the validation was conducted independently by designated chemists who were not involved in the sample collection and HRS evaluation [ 35, pp. 179 - 180, 183; 64, pp. 1, 4 ]. As part of this HRS documentation record and the evaluation of background concentrations, the following hazardous substances in background sedi ment samples are presented: chromium and lead. Among the three background sediment samples , chromium was detected at a maximum concentration of 9.9 J mg/Kg in samples SD - 01C and SD - 03; and lead was detected at a maximum concentration of 35.8 J mg/Kg in sample SD - 01C [18, pp. 5 - 6, 9, 11 - 12; 28, p. 63; 64, p. 9; 73, pp. 7, 53, 54, 58].Source Characterization Source No. 3

Wa lton & Lonsbury Inc. 55 HRS Documentation Record MAD001197755 September 2012 Table 13 - Hazardous Substa nces Associated with Background Samples Sample ID Sample Type Date Hazardous Substance Hazardous Substance Concentration Bias * Sample Adjusted

CRQL Reference SD - 01C Sediment 25 Jan. 2012 Chromium 9.9 J (12.8) mg/Kg Unknown 2 mg/Kg 18, pp. 5 - 6, 11 - 12; 28, p. 63 ; 64, p. 9 ; 73, p p . 1 - 2, 7 , 53 Lead 35.8 J (51.6) mg/Kg Unknown 2 mg/Kg SD - 01D Sediment 25 Jan. 2012 Chromium 8.5 J (11) mg/Kg Unknown 1.1 mg/Kg 18, pp. 5 - 6, 11 - 12; 28, p. 63 ; 64, p. 9 ; 73, p p . 1 - 2, 7 , 54 Lead 8.6 J (12.4) mg/Kg Unknown 1.1 mg/Kg SD - 03 Sediment 26 Jan. 2012 Chromium 9.9 J (12.8) mg/Kg Unknown 0.9 mg/Kg 18, pp. 9, 11 - 12; 28, p. 63 ; 64, p. 9 ; 73, p p . 1 - 2, 7 , 58 Lead 14 .0 J (20.2) mg/Kg Unknown 0.9 mg/Kg Jan. = January CRQL = Contract Required Quantitation Limit mg/Kg = Milligrams per K ilogram J = The associated numerical value is an estimated quantity and the bias resulting from the estimate has been considered as explained below [73, p. 7]. ( ) = For hazardous substance concentrations, denotes concentration of the compound or element following adjustment. B ased on the EPA Fact Sheet Using Qualified Data to Document an Observed Release and Observed Contamination , for HRS purposes it is not re quired to adjust qualified data for sources . Although t he fact sheet was not intended for application to source data, it has been applied in this situation to demonstrate the relative increase in contamination in the samples over background levels [70]. * An explanation for the direction of the bias is provided in Reference 73, Table 3.

- Samples: On 25 January 2012, as part of the EPA SR and in accordance with the EPA - approved January 2012 Site Specific QAPP , sedimen t sampling activities for the Surfa ce Impoundment Area Source (Source No. 3) were conducted [ 18, pp. 5, 7, 11 - 12 ; 28, pp. 19 - 20, 64 ; 31, pp . 1, 26, 30, 36, 38 ]. As part of the Source No. 3 characterization, two sediment samples (SD - 05A and SD - 0 7 A) were collected from within the area determined to be encompassed by Source No. 3 [ 18, pp. 4, 7, 11 - 12; 28, pp. 18, 20 , 64 - 65 ; 41 ]. Three additional sediment samples ( SD - 04B and field duplicate SD - 08B , and SD - 0 6 A ) were collected from nearby locations within the wetland area delineated by EPA [18, pp. 5 , 9 , 11 - 12 ; 28, pp. 19, 22, 64 - 65 ; 103, pp. 10, 26 ]. The five sediment samples collected from Source No. 3 and surrounding wetland areas during the EPA SR were collected from depths down to 2 feet bgs [28, pp. 64 - 65; 35 , pp. 185 - 186, 188, 190 ]. Locations of the sediment samples collected from Source No. 3 and surrounding wetland areas are depicted in Figure 7. Sediment samples collected from Source No. 3 and surrounding wetland areas were of similar composition to the native matrix materials described in the background sediment samples presented forSource Characterization Source No. 3

Wa lton & Lonsbury Inc. 56 HRS Documentation Record MAD001197755 September 2012 Source No. 3. Sediment sample SD - 04B and field duplicate sample SD - 08B were described as saturated, dark brown - to - olive, organics and silt, little fine - to - coarse sand, trace clay [35, p. 185] . Sediment sample SD - 05A was described as dark brown, organics, some silt, trace clay, trace fine - to - coarse sand [35, p. 186] . Sediment sample SD - 06A was described as saturated, dark brown, organics, some silt, little clay, trace fine - to - coarse sand [35, p. 188] . Sediment sample SD - 07A was described as dark brown, silt and fine - to - coarse sand, some organics, trace clay, fine - to - medium gravel [35, p. 190] . The five sediment samples (SD - 04B, SD - 05A, SD - 06A, SD - 07A, and SD - 08B) were submitted to a CLP l aboratory for chromium and lead analysis under CLP SOW ISM01.3 [18, pp. 11 - 12; 32, p. 10; 54, pp. 1, 9; 64, pp. 1, 9]. COCs for all samples collected as part of the 2012 EPA SR and presented in this HRS documentation record are provided in Reference 32. The applicable COC page s for the five sediment samples , and all corresponding sample identifiers , are provided in available COC and field notes reference documentation [18, pp. 4 - 5, 7, 9, 11 - 12; 32, p. 10]. In addition, all sample IDs and associated sample numbers and COC numbers are provided in a reference table [115]. The analytical data for the five sediment samples were validated on a Tier II level according to EPA Region I Tiered Organic and Inorganic Da ta Validation Guidelines [ 54, pp. 1, 5; 64, p. 1, 4 ]. I n addition, the validation was conducted independently by designated chemists who were not involved in the sample collection and HRS evaluation [ 35, pp. 185 - 186, 188, 190; 54, pp. 1, 5; 64, p. 1, 4 ]. Among the five sediment samples, chromium was detected at a maximum concentration of 28,300 J mg/Kg in sediment sample SD - 06A, collected from the southeastern portion of the area which was determined, based on interpretation of 1961 aerial imagery, to be encompassed by the Surface Impoundment Area Source (see Figure 7) [18 , pp. 4 - 5, 7, 9, 11 - 12; 28, p. 64; 41; 54, p. 9; 74, pp. 7, 5 1 - 52 ; 90]. L ead was detected at a maximum concentration of 1,310 J mg/Kg in sediment sample SD - 05A, collected from the central - southern portion of the S urface Impoundment Area Source (see Figure 7) [ 18, pp. 4 - 5, 7, 9, 11 - 12; 28, p. 64 ; 41; 54, p. 9 ; 74, p p . 7 , 5 1 - 52 ; 90]. Based on chemical analysis of sediment samples collected as part of the EPA SR, Source No. 3 has been documented to contain the hazardous substances chromium and lead at concentrations significantly above background concentrations [ 1, p. 51586; 7 , pp. 7, 14 - 15 ; 8 , pp. 52 - 56; 28, p p . 64 - 65 ; 54, p. 9; 64, p. 9; 73, p p. 8 , 57, 59 - 60; 74, pp. 7, 5 1 - 5 2 ]. Therefore, Source No. 3 has been documented to contain hazardous substances as defined by the HRS Rule [1, p. 51586; 7 , pp. 7, 14 - 15 ; 8 , pp. 52 - 56 ]. C hromium and lead are considered to be associated with the Surface Impoundment Area Source [1, p. 51588, Section 2.2.2]. Table 14 - Hazardous Substances Associated with Source No. 3 Sample ID Sample Type Date Hazardous Substance Hazardous Substance Concentration Bias* Sample Adjusted

CRQL Reference
SD - 04B Sediment 26 Jan. 2012 Chromium 2,320 J (1,798) mg/Kg Unknown 1 mg/Kg 18, pp. 9, 11 - 12; 28, p. 64 ; 64, p. 9 ; 73, p p. 1 - 2, 8 , 59 SD - 05A Sediment 25 Jan. 2012 Chromium 26,500 J (20,540) mg/Kg Unknown 10 mg/Kg 18, pp. 7, 11 - 12; 28, p. 64 ; 54, p. 9 ; 74, p p . 1 - 2, 7 , 51 Lead 1,310 J (910) mg/Kg Unknown 1 mg/KgSource Characterization Source No. 3

Wa lton & Lonsbury Inc. 57 HRS Documentation Record MAD001197755 September 2012 Table 14 - Hazardous Substances Associated with Source No. 3 Sample ID Sample Type Date Hazardous Substance Hazardous Substance Concentration Bias* Sample Adjusted

CRQL Reference SD - 06A Sediment 25 Jan. 2012 Chromium 28,300 J (21,940) mg/Kg Unknown 10 mg/Kg 18, pp. 5, 11 - 12; 28, p. 64 ; 54, p. 9 ; 74, p p. 1 - 2, 7 , 52 Lead 539 J (374) mg/Kg Unknown 1 mg/Kg SD - 07A Sediment 25 Jan. 2012 Chromium 4,860 J (3,767) mg/Kg Unknown 2.4 mg/Kg 18, pp. 4, 11 - 12; 28, p. 65 ; 64, p. 9 ; 73, p p . 1 - 2, 8 , 57 Lead 250 J (174) mg/Kg Unknown 2.4 mg/Kg SD - 08B Sediment 26 Jan. 2012 Chromium 4,320 J (3,349) mg/Kg Unknown 1.4 mg/Kg 18, pp. 9, 11 - 12; 28, p. 65 ; 64, p. 9 ; 73, p p . 1 - 2, 8 , 60 Lead 342 J (238) mg/Kg Unknown 1.4 mg/Kg Jan. = January CRQL = Contract Required Quantitation Limit mg/Kg = Milligrams per K ilogram J = The associated numerical value is an estimated quantity and the bias resulting from the estimate has been considered as explained below [74, p. 7]. ( ) = For hazardous substance concentrations, denotes concentration of the compound or element following adjustment. B ased on the EPA Fact Sheet , Using Qualified Data to Document an Observed Release and Observed Contamination for HRS purposes it is not requi red to adjust qualified source data . Although t he fact sheet was not intended for application to source data, it has been applied i n this situation to demonstrate the relative increase in contamination in the source samples over background levels [70]. * An explanation for the direction of the bias is provided in Reference 73, Table 4 and Reference 74, Table 3. List of Hazardous Substances Associated with Source Chromium Lead 2.2.3 HAZARDOUS SUBSTANCES AVAILABLE TO A PATHWAY Surface water flows in a southerly direction through the Surface Impoundment Source Area and the surrounding wetlands, toward a drainage culvert near the corner of Deanville Road and North Avenue [19, p. 2 ; 28, p. 10; 103, p. 2]. Based on observations and investigations conducted as part of the 2012 EPA SR , as well as information provided by City of Attleboro , MA Department of Public Works (DPW) personnel, surface water entering the drainage culvert then flows south - southeast through piping underneath Deanville Road [18, pp. 16, 25; 21]. Surface water flows through the piping to a manhole on a residential property designated during the EPA SR as “P - 09”, identified on the City of Attleboro Tax Assessor's Map No. 49, as Lot No. 114B [18, pp. 16, 25; 21 ; 69 ]. On 2 Febru ary 2012, as part of the EPA SR , one sediment sample (SD - 09) was collected from the manhole on property “P - 09”, to document migration of contamination downstream from the wetland area [18, p. 25; 28, pp. 37, 65]. SedimentSource Characterization Source No. 3

Wa lton & Lonsbury Inc. 58 HRS Documentation Record MAD001197755 September 2012 sample SD - 09 was su bmitted to a CL P l aboratory for chromium and lead analysis under CLP SOW ISM01.3 [18, pp. 27 - 28; 32, p. 11; 53, pp. 1, 12]. The analytical result s w ere validated on a Tier II level according to EPA Region I Tiered Organic and Inorganic Data Validation Guidelines ; in add ition, the validation was conducted independently by designated chemists who were not involved in the sample collection and HRS evaluation [ 35, pp. 186; 53, pp. 1, 4, 12]. Analytical results of SD - 09 indicated a chromium concentration of 672 mg/Kg, meeting the criteria for establishing an observed release [ 1, p. 51589 (Table 2 - 3); 53, p. 12; 72, pp. 22, 77] . Therefore, analytical results of chromium in sediment sample SD - 09, collected from a manhole downstream of Source No. 3, indicate evidence of hazardous substance migration from Source No. 3. Based on evidence of hazardous substance migration from the source, Source No. 3 does not have full containment, and the source yields a containment value of 10 for the overland flow component o f the Surface Water pathway [1, p. 51 610 (Table 4 - 2)]. In addition, surface water within the wetland which encompasses Source No. 3 was observed to flood south from the wetland, over Deanville Road, and onto residential properties located along Deanville R oad [18, p. 28]. Therefore, field observations, as well as documentation provided by the City of Attleboro, MA DPW , indicate a lack of fully functioning diking for Source No. 3 [18, p. 28; 21]. Table 15 - Hazardous Substances Available to Pathways Containment Description Containment Factor References Release via overland migration and/or flood : Based on evidence of hazardous substance migration, as well as a lack of maintained diking , a Containment Factor Value of 10 has been assigned for release v ia overland migration and/or flood for Source No. 3 . 10 1, p. 51 610 (Table 4 - 2) ; 18, p. 25 , 27 - 28 ; 21; 28, pp. 37, 65; 32, p. 11; 53, pp. 1, 12 2.4.2 HAZARDOUS WASTE QUANTITY 2.4.2.1 Hazardous Waste Quantity The Hazardous Waste Quantity for Source No. 3 was assigned based on the Area Assigned Value of a “ surface impoundment” source type [1, p. 51591 (Table 2 - 5, Section 2.4.2.1. 4 )]. The Hazardous Constituent Quantity, Hazardous Wastestream Quantity, and Volume Assigned Values were not evaluated for Source No. 3 because insufficient information was available , as described in the sections below [1, p. 51591 (Table 2 - 5, Sections 2.4.2.1.1 , 2.4.2.1.2 and 2.4.2.1. 3 )]. 2.4.2.1.1 Hazardous Constituent Quantity Description The H azardous C onstituent Q uantity for Source No. 3 could not be adequately determined according to the HRS Rule requirements; that is, the total mass of all CERCLA hazardous substances in the source and releases from the source is not known a nd cannot be estimated with reasonable confidence [1, pp. 51590 - 51591 (Section 2.4.2.1.1)]. Insufficient h istorical and current data (m anifest s, PRP records, State records, permits, w aste concentration data, etc.) are available to adequately calculate the total mass of all CERCLA hazardous substances in the source and the associated releases from the source. Therefore, there is insufficient information to calculate the H azardous C onstituent Q uantity for Source No. 3 with reasonable confidence.Source Characterization Source No. 3

Wa lton & Lonsbury Inc. 59 HRS Documentation Record MAD001197755 September 2012 Table 16 – Hazardous Constituent Quantity Hazardous Substance Constituent Quantity (pounds) References NS (insufficient information) Sum (pounds): Hazardous Constituent Quantity Assigned Value: NS 2.4.2.1.2 Hazardous Wastestream Quantity Description The H azardous W astestream Q uantity for Source No. 3 could not be adequately determined according to the HRS Rule requirements; that is, the total mass of all hazardous wastestreams and CERCLA pollutants and contaminants for the source and releases from the sou rce is not known and cannot be estimated with reasonable confidence [1, p. 51591 (Section 2.4.2.1.2)]. Insufficien t historical and current data (m anifest s, PRP records, State records, permits, waste concentration data, a nnual reports, etc.) are available t o adequately calculate the total mass of all hazardous wastestreams and CERCLA pollutants and contaminants for the source and the associated releases from the source. Therefore, there is insufficient information to adequately calculate or extrapolate the H azardous W astestream Q uantity for Source No. 3 with reasonable confidence. Table 17 – Hazardous Wastestream Quantity Hazardous Waste s tream Waste s tream Quantity (pounds) References NS (insufficient information) Sum (pounds): Sum of Waste s tream Quantity/5,000 ( 1, p. 51591, Table 2 - 5 ): Hazardous Waste s tream Quantity Assigned Value : NS 2.4.2.1.3 Volume Description The volume for Source No. 3 could not be adequately determined according to the HRS Rule requirements because insufficient historical and current waste sampling data are available to adequately calculate the volume of the source with reasonable confidence [1, p. 51591 (Section 2.4.2.1.3)]. Insufficient historical or current sampling data are available to adequately estimate the depth of waste material with in the source. Therefore, there is insufficient information to adequately calculate or estimate the volume for Source No. 3 with reasonable confidence.Source Characterization Source No. 3

Wa lton & Lonsbury Inc. 60 HRS Documentation Record MAD001197755 September 2012 Table 18 – Volume Source Type Description (# drums or dimensions) Units (yd 3 ) References NS (insufficient information) Sum (yd 3 ): Equation for Assigning Value ( 1, p. 51591, Table 2 - 5 ): Volume Assigned Value: NS 2.4.2.1.4 Area Description Aerial imagery from 1961 was utilized to determine the area of Source No. 3 (see Figure 6) [41; 90]. The 1961 aerial imagery indicates evidence of the surface impoundment south of the Walton & Lonsbury Inc. facility building [90]. Based on an interpretatio n of the 1961 aerial imagery, the historical surface impoundment consi sted of two areas of open water [41; 90]. A trench connecting the two areas of open water is apparent in the 1961 aerial imagery, and remnants of the trench were also observed during se diment sampling activities conducted as part of the 2012 EPA SR [41; 90]. No other information regarding the areal extent of the historical surface impoundment south of the Walton & Lonsbury Inc. property was found in available file documentation. Based on a 1950 topographical map and a 1988 RCA figure, the area historically encompassed by the surface impoundment, as determined by interpretation of the 1961 aerial imagery, consisted of generally level topography and wetland areas, similar to the con ditions observed in 2012 [11, p. 2; 90; 91; 103, pp. 7 - 10]. A 1990 report by RCA indicates that at the time of the report, portions of the Walton & Lonsbury Inc. property, as well as adjacent properties to the south and west, exhibited the characteristics of a wetland; however, no formal wetland delineation was found in available documentation [17, p. 1 6 ]. Therefore, i t is unknown based on available documentation whether the historical surface impoundment covered additional portions of the wetland than thos e areas identified via interpretation of the 1961 aerial imagery, or whether the surface impoundment historically extended to the boundaries of the wetland area as mapped by EPA in 2012 ( which encompasses 8.5 acres) [103, pp. 10, 26]. A nalytical results o f sediment samples collected during the EPA SR from Source No. 3 , and analytical results of additional sediment samples collected from nearby locations in the surrounding wetland, document contamination within 8.5 acres of wetlands [1, p. 51588, Section 2.2.2]. However, only the smaller area identified as open water via interpretation of the 1961 aerial imagery is presented as the area of Source No. 3, although the source area could be larger [41; 90]. Based on the 1961 aeri al imagery depicting the surface impoundment areas, and areal calculations conducted using GIS software, the area of Source No. 3 was determined to be 130,389 ft 2 [41].Source Characterization Source No. 3

Wa lton & Lonsbury Inc. 61 HRS Documentation Record MAD001197755 September 2012 Table 19 – Area Source Type Units (ft 2 ) References Surface Impoundment 130,389 41 ft 2 = Square Feet The area of a “ surface impoundment ” source, in ft 2 , is divided by 13 to assign a Hazardous Waste Quantity to the source [1, p. 51591, Table 2 - 5]. Sum (ft 2 ): 130,389 Equation for Assigning Value ( 1, p. 51591, Table 2 - 5 ): 130,389 ft 2 ÷ 13 = 10,029.9 Area Assigned Value: 10,0 29.9 2.4.2.1.5 Source Hazardous Waste Quantity Value The Hazardous Waste Quantity Value for Source No. 3 was assigned based on the Area Assigned Value ( 10,030 ) [1, p. 51591, Table 2 - 5]. The Hazardous Constituent Quantity, Hazardous Wastestream Quantity, and Volume Assigned Values were not evaluated for Source No. 3 because insufficient information was available [1, p. 51591, Sections 2.4.2.1.1, 2.4.2.1.2, 2 .4. 2.1.3 ]. Highest HWQ value assigned from Ref. 1, Table 2 - 5: 10,029.9So urce Characterization Source No. 4

Walton & Lonsbury Inc. 62 HRS Documentation Record MAD001197755 September 2012 2.2 SOURCE CHARACTERIZATION 2.2.1 SOURCE IDENTIFICATION Name of S ource : Contaminated Soil Source Area A Number of S ource : Source No. 4 Source Type : Contaminated Soil Description and Location of Source : Contaminated Soil Source Area A ( Contaminated Soil - Source No. 4 ) comprises 12,308.96 ft 2 ( 0. 28 acres ) located on portions of seven properties located south of the Walton & Lonsbury Inc. property (see Figure 8) [10; 12; 66; 71 , pp. 1 - 2 , 6 ]. These seven properties are depicted on the City of Attleboro, MA Tax Assessor’s Map No. 49, as Lot Nos. 113, and 114B; and on Map No. 59, as Lot Nos. 190A, 220, 225, 227, and 228 [12 ; 68; 69]. The geographic coordinates of Source No. 4 , as measured from its approximate center, are 41° 57 ′ 18.1 ′′ north latitude and 71° 17 ′ 49.3 ′′ west longitude [11 ; 71 , pp. 1 - 2 ]. The majority of Source No. 4 is located along the western portions of residential properties along North Avenue, south of the Walton & Lonsbury Inc. property and adjacent to (east of) wetland areas (see Figure 3). A Surface Impoundment Source (Source No. 3) has been documented within the wetlands south of the Walton & Lonsbury Inc. property (see Source No. 3 section above). Analytical results of samples collected from the wetland and Source No. 3 during the EPA EPRB SI and the 2012 EPA SR have indicated extensive chromium and lead con tamination throughout these areas [ 16, pp. 6 - 8, 21; 28, p p . 64 - 65 ; 54, p. 9; 64, p. 9; 73, p p. 8 , 57, 59 - 60; 74, pp. 7, 5 1 - 5 2 ]. Based on topography and previous reports, stormwater runoff/overland flow from the Walton & Lonsbury Inc. property flows in a southeasterly direction, toward the wetland located south of the property [ 11, p. 2 ; 24, p. 11 ; 25, p. 32 ]. A 1989 report prepared by RCA , for Walton & Lonsbury Inc., indicated that terrain in the area of the Walton & Lonsbury Inc. property is relativel y flat, with a gradual slop e toward the southeast [24, p. 11 ]. The RCA report further stated that at the time of the report, all runoff from the paved parking lot and the Walton & Lonsbury Inc. building roof flowed off the property in a southeasterly direction, into low - lying area s and wetlands south of the Walton & Lonsbury Inc. facility building [24, p. 11 ]. Previous reports prepared by RCA, on behalf of Walton & Lonsbury Inc., identified surface water run - off as a potential source of chromium contamination to the wetland [17, p. 8 - 9, 11 ; 23, p. 47; 24, pp. 13 , 19 ]. A 1989 RCA report states that a potential historical source of chromium contamination to portions of the wetland was surface water run - off of chromium - contamina ted residue from the electrical room roof of the building , due to the roof’s proximity to exhaust ducts from the facility’s chromium plating tanks [24 , pp. 11 , 19 , 49 ]. Based on on - site observations made during sampling activities conducted as part of the 2012 EPA SR , surface water runoff currently flows off the Walton & Lonsbury Inc. property in a southeasterly direction toward a low - lying area of open water, prior to discharging to the wetland south of the property [18, p. 29 ; 103, p. 4 ]. D uring the 2012 EPA SR, s urface soil/source samples were collected from Source No. 4 within low - lying areas along the western portions of residential properties along North Avenue, east of Source No. 3 and the surrounding wetland areas [18, pp. 15 - 16, 23; 28, pp. 67, 69 - 73, 83 ]. Based on site topography and on - site observations, the low - lying areas along the western portions of residential properties along North Avenue are subject to surface water flooding from the wetlands [11; 18, pp. 15 - 16, 23 ; 19, pp. 2, 6; 109, pp. 1, 4 ]. Source No. 4 also includes an area of contaminated soil on portions of two properties along DeanvilleSo urce Characterization Source No. 4

Walton & Lonsbury Inc. 63 HRS Documentation Record MAD001197755 September 2012 Road, south of the wetland downstream of the Walto n & Lonsbury Inc. property; these two properties were designated during the 2012 EPA SR as “P - 07” and “P - 09” [18, pp. 13, 15 - 16; 28, pp. 28, 71 - 7 3 ]. Surface water from Source No. 3 and the surrounding wetlands f lows south toward a drainage culvert , located in the southeastern portion of the wetlands near the corner of Deanville Road and North Avenue [19, p. 2 ; 28, p. 10; 103, p. 4 ]. Drainage problems have been documented for surface water within the wetlands south of the Walton & Lonsbury Inc. property , because the drainage culvert , which extends south - southeast from the wetlands through piping underneath Deanville Road, is damaged and partially blocked [16, p. 8; 21]. Based on observations and investigations conducted as part of the EPA SR , as well as information provided by City of Attleboro , MA personnel, surface water from the wetlands enter s the drain age culvert and flows south - southeast through piping underneath Deanville Road, to a manhole on a residential property (“P - 09”) along the southern side of Deanville Road [18, pp. 13, 16, 25; 21]. On 2 February 2012, as part of the EPA SR , one sediment samp le (SD - 09) was collected from the manhole on property “P - 09” , identified on the City of Attleboro Tax Assessor's Map No. 49, as Lot No. 114B , to document migration of contamination downstream from the wetland [18, p. 25; 28, pp. 37, 65; 69]. Validated anal ytical results of SD - 09 indicated a chromium concentration of 672 mg/Kg, significantly above background concentrations [18, pp. 27 - 28; 32, p. 11; 53, pp. 1, 12; 72, pp. 22, 77]. Based on an interview with a resident at property P - 09 (City of Attleboro Tax Assessor's Map No. 49, Lot No. 114B ), surface water has occasion ally overflowed from the manhole and flooded portions of the property , including a portion of the property within Source No. 4 [18, p. 16]. Low - lying areas in the northern portions of multiple properties along the southern side of Deanville Road, south of the wetland located south of the Walton & Lonsbury Inc. property, have been observed to be subject to flooding from surface wa ter flow ing across Deanville Road from the wetland [18, pp. 16, 28]. The area of Source No. 4 was determined to be 12,308.96 ft 2 . Th e area includes the Source No. 4 surface soil/source sampl e locations which document significant contamination with chromium and lead, as presented below , and the are a lying between these locations ; with the exception of areas which are covered with permanent water cover and wetlands ( 10,641.50 ft 2 ) [ 28, pp. 67, 69 - 73, 83; 53, p. 9; 60, pp. 7, 8; 71 , pp. 1 - 2 ; 72, pp. 33, 34, 36, 37, 42 - 46, 64, 74, 75, 78, 79 ]. The area lying between Source No. 4 surface soil /source sample locations is inferred to be contaminated due to the likely mechanism of contaminant transport (flooding). All of the Source No. 4 surface soil/source sample locations and the entirety of the area of inferred contamination lying between these locations are within an area of the same topographical elevation [ 109, pp. 1, 4 ] . In addition, Source No. 4 surface soil/source sample locations west of North Avenue and north of D ean ville Road, and the areas of inf erred contamination lying between these locations, are adjacent to a wetland and within the same topographical elevation [ 109, pp. 1, 4 ]. The area of inferred contamination between con taminated surface soil/source sample locations and beneath Deanville Road is presumed to have be en historically subject to flooding prior to installation of the roadway, as recent on - site observations and documentation ha ve indicated that surface water con tinues to occasionally flood from the wetland to the south across Deanville Road due to drainage problems with in the wetland [18, p. 28; 21]. The area of inferred contamination between contaminated Source No. 4 surface soil/source sample locations on prope rties south of Deanville Road is presumed to be contaminated due to the area topography, observed flooding in nearby areas, and an interview with a property owner [ 109, pp. 1, 4; 18, p. 16 , 28 ]. 2.2.2 HAZARDOUS SUBSTANCES ASSOCIATED WITH THE SOURCE

- Background Concentrations: Source No. 4 is a contaminated soil source type; therefore, background surface soil samples have been utilized to show the soil contamination is above background levels . Between 25 January and 1 February 2012, as part of the EPA SR and in accordance with the EPA - approved January 2012 Site - SpecificSo urce Characterization Source No. 4

Walton & Lonsbury Inc. 64 HRS Documentation Record MAD001197755 September 2012 QAPP, background surface soil sampling activities were conducted [ 18, pp. 4, 15, 18 - 22; 28, pp. 18, 27 - 28, 30 - 33, 61, 71, 76 - 77, 79, 81 ; 31, pp. 1, 26, 28, 33 - 34, 42 ]. Ten background surface soil samples were utilized to document natural background conditions in the local vicinity of the site. One background surface soil sample (S O - 01B) was collected from an undeveloped parcel located south of th e Walton & Lonsbury Inc. property, depicted on the City of Attleboro Tax Assessor's Map No. 59, as Lot No. 142 [12; 18, p. 4 ; 28, pp. 18, 61; 68]. Two background surface soil samples (P - 06 - SS - 07 and P - 06 - SS - 08) were collected from a residential property located south of the Walton & Lonsbury Inc. property, which is depicted on the City of Attleboro Tax Assessor's Map No. 59, as Lot No. 220 [12; 18, p. 15; 28, pp. 27 - 28, 71; 68]. One backgrou nd surface soil sample (P - 14 - SS - 01) was collected from a residential property located southeast of the Walton & Lonsbury Inc. property, which is depicted on the City of Attleboro Tax Assessor's Map No. 49 , as Lot No. 157D [10; 12; 18, p. 21; 28, pp. 33, 76 ; 69]. Two background surface soil samples (P - 16 - SS - 03 and P - 16 - SS - 04) were collected from a residential property located southeast of the Walton & Lonsbury Inc. property, which is depicted on the City of Attleboro Tax Assessor's Map No. 49 , as Lot No. 157B [10; 12; 18, pp. 21 - 22; 28, pp. 33, 77; 69]. One background surface soil sample (P - 18 - SS - 04) was collected from a residential property located southeast of the Walton & Lonsbury Inc. property, which is depicted on the City of Attleboro Tax Assessor's Map No. 49 , as Lot No. 96 [10; 12; 18, p. 18; 28, pp. 30, 79; 69]. Three background surface soil samples (P - 22 - SS - 01A, P - 22 - SS - 01B, and P - 22 - SS - 08) were collected from a residential property located southeast of the Walton & Lonsbury Inc. proper ty, which is depicted on the City of At tleboro Tax Assessor's Map No. 4 9, as Lot No. 126 [10; 12; 18, pp. 19 - 20; 28, pp. 31 - 32, 81; 69]. All background surface soil sample locations are depicted in Figure 4. The 10 background surface soil samples were col lected in the vicinity of the site from the same depth interval ( 0 - to 2 - f eet bgs), during the same time period , and utilizing the same collection and analytical methods as the surface soil/ source samples presented as part of the Source No. 4 c haracterizat ion [ 18, pp. 4, 14 - 16, 18 - 23 , 25, 27 - 28; 28, pp. 18, 27 - 33, 35, 61, 69, 71 - 73 , 76 - 77, 79, 81; 32, pp. 12, 14 - 16; 35, pp. 3, 5, 23, 26, 38 - 39, 43 - 44, 46, 53, 58, 91, 102 - 103, 117, 137 - 138, 145, 163 ; 50, p. 1; 53, p. 1; 60, p. 1; 61, p. 1 ]. Background surface soil sample SO - 01B was described as moist, yellow brown, silt, some fine sand, little clay, trace medium - to - coarse gravel, trace organics, trace medium - to - coarse sand [35, p. 163]. Background surface soil sample P - 06 - SS - 07 was described as brown - to - dark brown, fine - to - coarse sand, some silt, little fine - to - medium gravel, trace organics , trace clay [35, p. 43] . Background surface soil sample P - 06 - SS - 08 was described as brown, silt and fine - to - coarse sand, little fine - to - medium gravel, trac e organics, trace clay [35, p. 44] . Background surface soil sample P - 14 - SS - 01 was described as dry, brown, silt , trace clay, trace fine - to - coarse sand, trace fine - to - medium gravel, trace organics [35, p. 9 4 ] . Background surface soil sample P - 16 - SS - 03 was d escribed as moist, brown - to - dark brown, clay, some silt, trace organics, trace fine gravel, trace fine - to - coarse sand [35, p. 102] . Background surface soil sample P - 16 - SS - 04 was described as wet, brown - to - dark brown, clay and silt, trace organics, trace fine to - coarse sand [35, p. 103] . Background surface soil sample P - 18 - SS - 04 was described as brown, fine - to coarse sand, little silt, little clay, trace fine - to - medium gravel, trace organics [35, p. 117] . Background surface soil sample P - 22 - SS - 01A was desc ribed as dark brown, silt, little organics, trace fine - to - coarse sand [35, p. 137] . Background surface soil sample P - 22 - SS - 01B was described as moist, dark brown, clay and silt, little fine - to - coarse sand, trace organics [35, p. 138] . Background surface s oil sample P - 22 - SS 08 was described as brown, fine - to - coarse sand, some silt, trace fine - to - medium gravel, trace clay, trace organics [35, p. 145] . As presented above, the 10 background surface soil samples contained varying compositions of naturally occu rring native matrix materials ( i.e. , sand, silt, clay, grav el, and organic matter), which co nstituted major and/or minor components of the sample [ 35, pp. 43 - 44, 9 4 , 102 - 103, 117, 137 - 138, 145, 163 ]. Similarly, the surface soil/ source samples presented as part of the Source No. 4 characterization exhibited varying compositions of the same naturally occurring native matrix materials (see Surface Soil/ SourceSo urce Characterization Source No. 4

Walton & Lonsbury Inc. 65 HRS Documentation Record MAD001197755 September 2012 Samples presented below). Among the 10 background surface soil samples, va rious samples contained native matrix material compositions that were similar to those of various surface soil/ source samples presented as part of the Source No. 4 c haracterization [ 35, pp. 3, 5, 23, 26, 38 - 39, 43 - 44, 46, 53, 58, 9 4 , 102 - 103, 117, 137 - 138, 145, 163 ]. The analytical results of each Source No. 4 surface soil/ source sample could be compared to the contaminant concentrations detected only in those background surface soil sample(s) which displayed the most similar matrix composition. However, fo r simplicity of th e HRS documentation record , and to support the case that analytical results of Source No. 4 surface soil/source samples are significantly above docum ented background concentrations, all 10 background surface soil samples are presented, an d Source No. 4 surface soil/source samples were compared to the highest concentrations detected among all 10 background surface soil samples for the analytes presented. Regardless of which approach is used for the comparison of contaminant concentrations [ i.e. , comparing Source No. 4 surface soil/source samples to only the background surface soil sample(s) that were most similar in composition, or comparing surface soil/source samples to the highest concentrations detect ed among all background surface soil samples] , surface soil/source sample analytical results for Source No. 4 indicate source contaminant concentrations significantly above background levels. Background surface soil sample s SO - 01B, P - 06 - SS - 07, P - 06 - SS - 08, P - 14 - SS - 01, P - 16 - SS - 03, P - 16 - SS 04, P - 18 - SS - 04, P - 22 - SS - 01A, P - 22 - SS - 01B, and P - 22 - SS - 08 were submitted to a CLP l aboratory for chromium and lead analysis under CLP SOW ISM01.3 [ 18, pp. 27 - 28; 32, pp. 9, 12, 14 - 15; 50, pp. 1, 9; 60, pp. 1, 7; 61, pp. 1, 8 - 9 ]. COCs for all samples collected a s part of the 2012 EPA SR and pr esented in this HRS d ocumentation r ecord are provided in Reference 32. The applicable COC pages for the background surface soil samples, and all corresponding sample identifiers, are provided in available COC and field notes reference documentation [18, pp. 4, 11 - 12, 15, 18 - 22, 25; 32, pp. 9, 12, 14 - 15]. In addition, all sample IDs and associated sample numbers and COC numbers are provided in a reference table [115]. The analytical data for background surface soil samples were validated on a Tier II level according to EPA Region I Tiered Organic and Inorganic Data Validation Guidelines [ 50, pp. 1, 3; 60, pp. 1, 3; 61, pp. 1, 3 ]. I n addition, the validation was conducted independently by designated chemists who were not involved in the sample collection and HRS evaluation [ 35, pp. 43 - 44, 94, 102 - 103, 117, 137 - 138, 145, 163; 50, p p . 1 , 3 ; 60, p p . 1 , 3 ; 61, p p . 1 , 3 ]. As part of this H RS documentation record and the evaluation of background concentrations, the following hazardous substances in background surface soil samples are presented: chromium and lead . A mong the 10 background surface soil samples , chromium was detected at a maximum concentration of 14.1 mg/Kg in sample P - 14 - SS - 01; and lead was detected at a maximum concentration of 76.4 mg/Kg in sample P - 22 - SS - 01A [ 18, pp. 4, 11 - 12, 15, 18 - 22, 25, 27 - 28; 28, pp. 61, 71, 76, 77, 79, 81; 50, p. 9; 60, p. 7; 61, pp. 8, 9; 72, pp. 2 3 - 28 , 30 - 31, 72, 74, 81, 82 , 84] . Table 20 - Hazardous Substances Associated with Background Samples Sample ID Sample Type Date Hazardous Substance Hazardous Substance Concentration Sample Adjusted

CRQL Reference SO - 01B Surface Soil 25 Jan. 2012 Chromium 10.7 mg/Kg 0.87 mg/Kg 18, pp. 4, 11 - 12 ; 28, p. 61 ; 50, p. 9 ; 72, pp. 1, 32, 72 Lead 10.1 mg/Kg 0.87 mg/Kg P - 06 - SS - 07 Surface Soil 31 Jan. 2012 Chromium 12.5 mg/Kg 0.98 mg/Kg 18, pp. 15, 27 - 28; 28, p. 71 ; 60, p. 7 ; 72, pp. 1, 2 3 , 74 Lead 23.4 mg/Kg 0.98 mg/KgSo urce Characterization Source No. 4

Walton & Lonsbury Inc. 66 HRS Documentation Record MAD001197755 September 2012 Table 20 - Hazardous Substances Associated with Background Samples Sample ID Sample Type Date Hazardous Substance Hazardous Substance Concentration Sample Adjusted

CRQL Reference P - 06 - SS - 08 Surface Soil 31 Jan. 2012 Chromium 10.3 mg/Kg 1.05 mg/Kg 18, pp. 15, 27 - 28; 28, p. 71 ; 60, p. 7 ; 72, pp. 1, 24, 74 Lead 31.4 mg/Kg 1.05 mg/Kg P - 14 - SS - 01 Surface Soil 1 Feb. 2012 Chromium 14.1 mg/Kg 1.41 mg/Kg 18, pp. 21, 27 - 28; 28, p. 76 ; 61, p. 8 ; 72, pp. 1, 25, 81 Lead 30.4 mg/Kg 1.41 mg/Kg P - 16 - SS - 03 Surface Soil 1 Feb. 2012 Chromium 12.0 mg/Kg 1.60 mg/Kg 18, pp. 21, 27 - 28; 28, p. 77 ; 61, p. 9 ; 72, pp. 1, 26, 81 Lead 59.9 mg/Kg 1.60 mg/Kg P - 16 - SS - 04 Surface Soil 1 Feb. 2012 Chromium 13.3 mg/Kg 1.34 mg/Kg 18, pp. 22, 27 - 28; 28, p. 77 ; 61, p. 9 ; 72, pp. 1, 27, 81 Lead 66.8 mg/Kg 1.34 mg/Kg P - 18 - SS - 04 Surface Soil 1 Feb. 2012 Chromium 11.0 mg/Kg 1.12 mg/Kg 18, pp. 18, 27 - 28; 28, p. 79 ; 61, p. 9 ; 72, pp. 1, 28, 81 Lead 29.4 mg/Kg 1.12 mg/Kg P - 22 - SS - 01A Surface Soil 1 Feb. 2012 Chromium 10.4 mg/Kg 1.67 mg/Kg 18, pp. 19, 27 - 28; 28, p. 81 ; 61, p. 9 ; 72, pp. 1, 81 , 84 Lead 76.4 mg/Kg 1.67 mg/Kg P - 22 - SS - 01B Surface Soil 1 Feb. 2012 Chromium 9.7 mg/Kg 1.44 mg/Kg 18, pp. 19, 27 - 28; 28, p. 81 ; 61, p. 9 ; 72, pp. 1, 30, 82 Lead 38.9 mg/Kg 1.44 mg/Kg P - 22 - SS - 08 Surface Soil 1 Feb. 2012 Chromium 10.0 mg/Kg 1.15 mg/Kg 18, pp. 20, 27 - 28; 28, p. 81 ; 61, p. 9 ; 72, pp. 1, 31, 82 ; 61, p. 9 Lead 51.5 mg/Kg 1.15 mg/Kg Jan . = January CRQL = Contract Required Quantitation Limit Feb. = February mg/Kg = Milligrams per K ilogram

- Source Samples: Between 31 January and 2 February 2012, as part of the EPA SR and in accordance with the EPA approved January 2012 Site - Specific QAPP , surface soil /source sampling activities for Source No. 4 were conducted [ 18, pp. 14 - 16, 18 - 23, 25, 27 - 28; 28, pp. 27 - 29, 35, 67, 69, 71 - 73 ; 31, pp. 1, 26, 32, 40 - 43 ]. As part of the Source No. 4 characterization, 10 surface soil /source samples were collected from residential properties located south of the Walton & Lonsbury Inc. property (samples P - 01 - SS - 02B, P - 01 - SS - 03B, P - 04 - SS - 03, P - 04 - SS - 06, P - 06 - SS - 02, P - 06 - SS - 03, P - 07 - SS - 02, P - 09 - SS - 02, P - 09 - SS - 07, and P 30 - SS - 02) (see Figure 8) [ 18, pp. 14 - 16, 23, 27 - 28; 28, pp. 27 - 29, 35, 61, 67, 69, 71 - 73 , 76, 77, 79, 81, 83 ]. Surface soil /source samples utilized to characterize Source No. 4 include two samples (P - 01 - SS - 02B and P - 01 - SS - 03B) collected from a property designated as “P - 01”, depict ed on the City of Attleboro Tax Assessor's Map No. 59, as Lot No. 190A; two surface soil/source samples (P - 04 - SS - 03 and P - 04 - SS - 06) collected from a property designated as “P - 04”, depicted on the City of Attleboro Tax Assessor's Map No.So urce Characterization Source No. 4

Walton & Lonsbury Inc. 67 HRS Documentation Record MAD001197755 September 2012 59, as Lot No. 225; two surface soil/source samples (P - 06 - SS - 02 and P - 06 - SS - 03) collected from a property designated as “P - 06”, depicted on the City of Attleboro Tax Assessor's Map No. 59, as Lot No. 220 ; two surface soil/source samples (P - 07 - SS - 02, and field duplicate P - 30 - SS - 02) collected from a property designated as “P - 07”, depicted on the City of Attleboro Tax Assessor's Map No. 49, as Lot No. 113; and two surface soil/source samples (P - 09 - SS - 02, P - 09 - SS - 07) collected from a property designated as “P - 09”, depicted on the City of Attleboro Tax Assessor's Map No. 49, as Lot No. 114B [12; 18, pp. 13 - 14; 68; 69 ]. All property designations ( e.g. , “P - 01”, “P - 02”, etc. ) were assigned during the 2012 EPA SR , and are associated with the corresponding identifiers for soil samples collected from each property ( e.g. , P - 01 - SS - ##, P - 02 - SS - ##, etc. ) [18, pp. 13 - 14]. All surface soil /source samples collected from Source No. 4 as part of the EPA SR were collected from depths less than 2 feet bgs [ 35, pp. 3, 5, 23, 26, 38 - 39, 46, 53, 58 ]. Surface soil/source samples collected from Source No. 4 were of similar composition to the native materials described in the background surface soil samples presented for Source No. 4. Surface soil sample P - 01 - SS - 02B was described as saturated, dark brown - to - black, silt, little clay, trace fine - to - coarse sand, trace organics [35, p. 3] . Surface soil/source sample P - 01 - SS - 03B was described as moist, dark brown, silt and clay, trace fine - to - coarse sand, little organics [35, p. 5] . Surface soil/source sa mple P - 04 - SS - 03 was described as saturated, dark brown, silt, some fine - to - coarse sand, little clay, trace fine - to medium gravel [35, p. 23] . Surface soil/source sample P - 04 - SS - 06 was described as saturated, silt, some fine - to - coarse sand, trace fine grave l, trace organics, trace clay [35, p. 26] . Surface soil/source sample P 06 - SS - 02 was described as moist, dark brown, fine - to - coarse sand and silt, trace organics, trace clay, trace fine gravel [35, p. 38] . Surface soil/source sample P - 06 - SS - 03 was describe d as wet, dark brown - to - black, silt and fine - to - coarse sand, trace fine - to - medium gravel, trace organics, trace clay [35, p. 39] . Surface soil/source sample P - 07 - SS - 02 and field duplicate P - 30 - SS - 02 were described as brown, fine - to - coarse sand and silt, li ttle fine - to - medium gravel, trace organics, trace clay [35, p. 46] . Surface soil/source sample P - 09 - SS - 02 was described as brown, fine - to - coarse sand, little silt, trace fine - to medium gravel, trace clay, trace organics [35, p. 53] . Surface soil/source sa mple P - 09 - SS - 07 was described as brown, silt, some fine - to - coarse sand, trace organics, trace fine gravel [35, p. 58] . The 10 surface soil /source samples (P - 01 - SS - 02B, P - 01 - SS - 03B, P - 04 - SS - 03, P - 04 - SS - 06, P - 06 - SS - 02, P - 06 - SS - 03, P - 07 - SS - 02, P - 09 - SS - 02, P - 09 - SS - 07, and P - 30 - SS - 02) were sub mitted to a CLP l aboratory for chromium and lead analysis under CLP SOW ISM01.3 [18, pp. 27 - 28 ; 32, pp. 12, 16; 53, pp. 1, 9; 60, pp. 1, 7 - 8 ]. COCs for all samples collected as part of the 2012 EPA SR and presented in this HRS d ocumentation r ecord are provided in Reference 32. The applicable COC pages for the Source No. 4 samples, and all corresponding sample identifiers, are provided in available COC and field notes reference documentation [ 18, pp. 14 - 16, 23; 32, pp. 12, 16]. In addition, all sample IDs and associated sample numbers and COC numbers are provided in a reference table [115]. The analytical data for Source No. 4 surface soil/source samples were validated on a Tier II level according to EPA Region I Tiered Organic and Inorganic Data Validation Guidelines [ 53, pp. 1, 4; 60, pp. 1, 3] . I n addition, the validation was conducted independently by designated chemists who were not involved in the sample collection and HRS evaluation [ 35, pp. 3, 5, 23, 26, 38 - 39, 46, 53, 58; 53, pp. 1, 4; 60, pp. 1, 3 ]. Among the 10 surface soil/source samples, chromium was detected at a maximum concentration of 617 mg/Kg in surface soil/source sample P - 07 - SS - 02, and lead was detected at a maximum concentration of 530 mg/Kg in surface soil/source sample P - 04 - SS - 06 [18, pp. 14 - 16, 23, 27 - 28; 28, pp. 67, 69 - 73, 83; 53, p. 9; 60, pp. 7, 8; 72, pp. 33, 34, 36, 37, 42 - 46, 63, 74, 75, 78 ]. Based on chemical analysis of surface soil/source samples collected during the EP A SR , Source No. 4 has been documented to contain chromium and lead , which are defined as hazardous substances according to the HRS Rule [ 1, p. 51586; 7 , pp. 7, 14 - 15 ; 8 , pp. 52 - 56; 28, pp. 67, 69 - 73, 83; 53, p. 9; 60, pp. 7, 8; 72, pp. 33, 34, 36, 37, 42 - 46, 63, 74, 75, 78]. The hazardous substances chromium and lead were detected inSo urce Characterization Source No. 4

Walton & Lonsbury Inc. 68 HRS Documentation Record MAD001197755 September 2012 Source No. 4 surface soil/source samples at concentrations significantly above background concentration s [18, pp. 14 - 16, 23, 27 - 28; 28, pp. 67, 69 - 73, 83; 53, p. 9; 60, pp. 7 , 8; 72, pp. 33, 34, 36, 37, 42 - 46, 63, 74, 75, 78]. Therefore, the hazardous substances chromium and lead are considered to be associ ated with Source No. 4 [ 1, p. 51588, Section 2.2.2 ]. O nly contaminated surface soil /source samples which contain hazardo us substance concentrations greater than or equal to three times background levels are present ed for the Source No. 4 characterization. Per the HRS, contaminated surface soil/source samples with hazardous substance concentrations above background levels, b ut less than three times background levels, could be presented as part of the source characterization. However, for the simplicity of this documentation record, and to identify a significant increase in source hazardous substance concentrations compared to background levels , only the contaminated surface soil /source samples with hazardous substance concentrations greater than or equal to three times background levels are presented . If a ll contaminated surface soil/source samples with hazardous s ubstance concentrations above background levels were included in the source characterization, the extent of contamination for Source No. 4 would be larger than the area delineated by the selection of surface soil/ source samples that are presented. Table 2 1 - Hazardous Substances Associated with Source No. 4 Sample ID Sample Type Date Hazardous Substance Hazardous Substance Concentration Sample Adjusted

CRQL Reference P - 01 - SS - 02B Surface Soil / Source 2 Feb. 2012 Chromium 119 mg/Kg 1.71 mg/Kg 18, pp. 23, 27 - 28; 28, p. 67 ; 53, p. 9 ; 72, pp. 1, 33, 78 P - 01 - SS - 03B Surface Soil / Source 2 Feb. 2012 Chromium 67.7 mg/Kg 1.69 mg/Kg 18, pp. 23, 27 - 28; 28, p. 67 ; 53, p. 9 ; 72, pp. 1, 34, 78 P - 04 - SS - 03 Surface Soil / Source 31 Jan. 2012 Chromium 112 mg/Kg 1.62 mg/Kg 18, pp. 15, 27 - 28; 28, p. 69 ; 60, p. 7 ; 72, pp. 1, 36, 74 Lead 338 mg/Kg 1.62 mg/Kg P - 04 - SS - 06 Surface Soil/ Source 31 Jan. 2012 Chromium 253 mg/Kg 1.45 mg/Kg 18, pp. 15, 27 - 28; 28, p. 70 ; 60, p. 7 ; 72, pp. 1, 37, 74 Lead 530 mg/Kg 1.45 mg/Kg P - 06 - SS - 02 Surface Soil/ Source 31 Jan. 2012 Chromium 147 mg/Kg 1.39 mg/Kg 18, pp. 14, 27 - 28; 28, p. 71 ; 60, p. 7 ; 72, pp. 1, 42, 74 P - 06 - SS - 03 Surface Soil/ Source 31 Jan. 2012 Chromium 187 mg/Kg 1.18 mg/Kg 18, pp. 14 , 27 - 28; 28, p. 71 ; 60, p. 7 ; 72, pp. 1, 43, 74 P - 07 - SS - 02 Surface Soil/ Source 31 Jan. 2012 Chromium 617 mg/Kg 0.87 mg/Kg 18, pp. 15, 27 - 28; 28, p. 71 ; 60, p. 7 ; 72, pp. 1, 44, 74 P - 09 - SS - 02 Surface Soil/ Source 31 Jan. 2012 Chromium 171 mg/Kg 0.77 mg/Kg 18, pp. 16, 27 - 28; 28, p. 72 ; 60, p. 8 ; 72, pp. 1, 45, 75 Lead 235 mg/Kg 0.77 mg/KgSo urce Characterization Source No. 4

Walton & Lonsbury Inc. 69 HRS Documentation Record MAD001197755 September 2012 Table 2 1 - Hazardous Substances Associated with Source No. 4 Sample ID Sample Type Date Hazardous Substance Hazardous Substance Concentration Sample Adjusted

CRQL Reference P - 09 - SS - 07 Surface Soil/ Source 31 Jan. 2012 Chromium 569 mg/Kg 1.08 mg/Kg 18, pp. 16, 27 - 28; 28, p. 73 ; 60, p. 8 ; 72, pp. 1, 46, 75 P - 30 - SS - 02 Surface Soil/ Source 31 Jan. 2012 Chromium 536 mg/Kg 0.82 mg/Kg 18, pp. 15, 27 - 28; 28, p. 83 ; 60, p. 8 ; 72, pp. 1, 6 3 , 7 5 Jan. = January CRQL = Contract Required Quantitation Limit. Feb. = February mg/Kg = Milligrams per Kilogram List of Hazardous Substances Associated with Source Chromium Lead 2.2.3 HAZARDOUS SUBSTANCES AVAILABLE TO A PATHWAY The area of Source No. 4 (12,308.96 ft 2 ) includes the locations of 10 surface soil/source sample s which document significant conta mination with chromium and lead, and the are a lying between these locations; with the exception of the areas which are covered with perman ent water cover or wetlands [ 28, pp. 67, 69 - 73, 83; 53, p. 9; 60, pp. 7, 8; 71 , pp. 1 - 2 , 6 ; 72, pp. 33, 34, 36, 37, 42 - 46, 63 , 74, 75, 78 ]. The total area between contaminated surface soil/source samples , including areas of permanent water cover and wetlands , was determined to be 22,950.46 ft 2 [ 71 , p p . 1 - 2 ]. B ased on on - site observations , wetland delineation activities, and an examination of aerial imagery using GIS software , t he area covered with permanent water cover or wetlands was determined to be 10 , 641.50 ft 2 [71 , pp. 1 - 2 ]. Therefore, b ased on analysis of GPS coordinates recorded for the locations of the 10 surface soil/source sample s presented above, analysis and interpretation of aerial photographs of the area , and on - site observations, the area of Source No. 4 not covered by water cover and wetlands is approximately 12,308.96 ft 2 ( 22,950.46 ft 2

- 10 , 641.50 ft 2 = 12,308.96 ft 2 ) [ 71 , pp. 1 - 2 ]. On - site observations indicate that no portion of Source No. 4 has a maintained engineered cover or complete run - on or runoff control management systems [ 18 , p. 28 ]. Th erefore, Source No. 4 does not have full containment, and the source yields a containment v alue of 10 for the overland flow component of the Surface Water pathway [1, p. 51609 (Table 4 - 2)]. Table 22 - Hazardous Substances Available to Pathways Containment Description Containment Factor References Release via overland migration and/or flood : Based on the lack of a maintained engineered cover, and any complete run on and runoff control management systems, a Containment Factor Value of 10 has been assigned for release via overland migration and/or flood for Source No. 4 . 10 1, p. 51609 (Table 4 - 2) ; 18 , p. 28; 71 , pp. 1 - 2, 6So urce Characterization Source No. 4

Walton & Lonsbury Inc. 70 HRS Documentation Record MAD001197755 September 2012 2.4.2 HAZARDOUS WASTE QUANTITY 2.4.2.1 Hazardous Waste Quantity The Hazardous Waste Quantity for Source No. 4 was assigned based on the Area Assigned Value of a “contaminated soil” source type [1, p. 51591 (Table 2 - 5, Section 2.4.2.1. 4 )]. The Hazardous Constituent Quantity, Hazardous Wastestream Quantity, and Volume Assigned Values were not evaluated for Source No. 4 because insufficient information was available , as described in the sections below [1, p. 51591 (Table 2 - 5, Sections 2.4.2.1.1 , 2.4.2.1.2 and 2.4.2.1. 3 )]. 2.4.2.1.1 Hazardous Constituent Quantity Description The H azardous C onstituent Q uantity for Source No. 4 could not be adequately determined according to the HRS Rule requirements; that is, the total mass of all CERCLA hazardous substances in the source a nd releases from the source is not known and cannot be estimated with reasonable confidence [1, pp. 51590 - 51591 (Section 2.4.2.1.1)]. Insufficien t historical and current data (m anifest s, PRP records, State records, permits, w aste concentration data, etc.) are available to adequately calculate the total mass of all CERCLA hazardous substances in the source and the associated releases from the source. Therefore, there is insufficient information to calculate the H azardous C onst i tuent Q uantity for Source No. 4 with reasonable confidence. Table 23 – Hazardous Constituent Quantity Hazardous Substance Constituent Quantity (pounds) References NS (insufficient information) Sum (pounds): Hazardous Constituent Quantity Assigned Value: NS 2.4.2.1.2 Hazard ous Wastes tream Quantity Description The H azardous W astestream Q uantity for Source No. 4 could not be adequately determined according to the HRS Rule requirements; that is, the total mass of all hazardous wastestreams and CERCLA pollutants and contaminants for the source and releases from the source is not known and cannot be estimated with r easonable confidence [1, p. 51591 (Section 2.4.2.1.2)]. Insufficien t historical and current data (m anifests, PRP re cords, State records, permits, waste concentration data, a nnual reports, etc.) are available to adequately calculate the total mass of all ha zardous wastestreams and CERCLA pollutants and contaminants for the source and the associated releases from the source. Therefore, there is insufficient information to adequately calculate or extrapolate the H azardous W astestream Q uantity for Source No. 4 with reasonable confidence.So urce Characterization Source No. 4

Walton & Lonsbury Inc. 71 HRS Documentation Record MAD001197755 September 2012 Table 24 – Hazardous Wastestream Quantity Hazardous Waste s tream Waste s tream Quantity (pounds) References NS (insufficient information) Sum (pounds): Sum of Waste s tream Quantity/5,000 ( 1, p. 51591, Table 2 - 5 ): Hazardous Waste s tream Quantity Assigned Value : NS 2.4.2.1.3 Volume Description The volume for Source No. 4 could not be adequately determined according to the HRS Rule requirements because insufficient historical and current waste sampling data are available to adequately calculate the volume of the source with reasonable confidence [1, p. 51591 (Section 2.4.2.1.3)]. Insufficient historical or current sampling data are available to adequately estimate the depth of waste material within the source. Th erefore, there is insufficient information to adequately calculate or estimate the volume for Source No. 4 with reasonable confidence. Table 25 – Volume Source Type Description (# drums or dimensions) Units (yd 3 ) References NS (insufficient information) Sum (yd 3 ): Equation for Assigning Value ( 1, p. 51591, Table 2 - 5 ): Volume Assigned Value: NS 2.4.2.1.4 Area Description The area of Source No. 4 includes the surface soil/source sampl e locations which document significant contamination with chromium and lead, and the area lying between these locations, with the exception of the areas which are covered with permanent water cover or wetlands [ 28, pp. 67, 69

– 73, 83; 53, p. 9; 60, pp. 7, 8; 71 , pp. 1 - 2, 6 ; 72, pp. 33, 34, 36 , 37, 42 - 46, 63 , 74, 75, 78 ]. The area of Source No. 4 was determined by connecting six contaminated surface soil /source sample GPS locations [P - 01 - SS - 02B, P 01 - SS - 03B, P - 04 - SS - 06, P - 06 - SS - 02, P - 07 - SS - 02/P - 30 - SS - 02 (field duplicate), and P - 09 - SS - 07] with straight lines, using GIS software [71 , pp. 1 - 2 ]. The total area between contaminated surface soil/source sample locations , including areas of permanent water cover and wetlands , was determined to be 22,950.46 ft 2 [ 71 , p p . 1 - 2 ]. The area covered with permanent water cover and wetlands was determined to be 10,641.50 ft 2 based on on - site observations, wetland delineation activities, and an examination of aerialSo urce Characterization Source No. 4

Walton & Lonsbury Inc. 72 HRS Documentation Record MAD001197755 September 2012 imagery using GIS software [71 , pp. 1 - 2 ]. Source No. 4 therefore comprises 12,308.96 ft 2 of contaminated soil ( 22,950.46 ft 2

- 10 , 641.50 ft 2 = 12,308.96 ft 2 ) . Table 26 – Area Source Type Units (ft 2 ) References Contaminated Soil 12,308.96 71 , pp. 1 - 2 ft 2 = Square Feet The area of a “contaminated soil” source, in ft 2 , is divided by 34,000 to assign a Hazardous Waste Quantity to the source [1, p. 51591, Table 2 - 5]. Sum (ft 2 ): 12,308.96 Equation for Assigning Value (1, p. 51591, Table 2 - 5): 12,308.96 ft 2 ÷ 34,000 = 0 . 36 Area Assigned Value: 0 . 36 2.4.2.1.5 Source Hazardous Waste Quantity Value The Hazardous W aste Quantity Value fo r Source No. 4 was assigned bas ed on the Area Assigned Value ( 0. 36 ) [1, p. 51591, Table 2 - 5]. The Hazardous Constituent Quantity, Hazar dous Wastestream Quantity, and Volume Assigned Values were not evaluated for Source No. 4 because insufficient information was available [1, p. 51591, Sections 2.4.2.1.1, 2.4.2.1.2 , 2.4.2.1.3 ]. Highest HWQ value assigned from Ref. 1, Table 2 - 5: 0.36Source Characterization Source No. 5

Walton & Lonsbury Inc. 73 HRS Documentation Record MAD001197755 5 September 2012 2.2 SOURCE CHARACTERIZATION 2.2.1 SOURCE IDENTIFICATION Name of S ource : Contaminated Soil Area B Number of S ource : Source No. 5 Source Type : Contaminated Soil Description and Location of Source : Contaminated Soil Area B ( Contaminated Soil - Source No. 5 ) comprises 12,333.88 ft 2 ( 0.28 acres ) located on portions of 11 properties located south east of the Walton & Lonsbury Inc. property (see Figure 9 ) [10; 12; 66; 71 , pp. 1 - 3 , 7 ]. These 11 properties are depicted on the City of Attleboro, MA Tax Assessor’s Map No. 49, as Lot Nos. 94, 95, 96, 97, 97A, 102A, 104, 109, 110, 111, and 112 [12; 69]. The g eographic coordinates of Source No. 5 , as measured from its approximate center, are 41° 57 ′ 14.9 ′′ north latitude and 71° 17 ′ 43.2 ′′ west longitude [11; 71 , pp. 1 - 3 ]. Source No. 5 is located southeast of the Walton & Lonsbury Inc . property and south of Paulette Lane , along the eastern portions of residential properties located east of North Avenue and immediately adjacent to ( west of ) Bliss Brook, and along the western portions of residential properties located west of Rounds Place and imme diately adjacent to ( east of ) Bliss Brook (see Figure 9) [ 18, pp. 18 - 19, 21 - 25, 27 - 28; 28, pp. 30 - 31, 33 - 36 , 49, 69, 70, 78 - 80, 83]. As part of the 2012 EPA SR , Source No. 5 surface soil/source samples were collected from low - lying areas on residential properties , adjacent to Bliss Brook [18, pp. 17 - 19, 2 2 - 25]. Based on site topography, flood zone data, and on - site observations, the low - lying areas of residential properties along Source No. 5 , adjacent to Bliss Brook, are known or suspected to be subject to surface water flooding from Bliss Brook [18, pp. 17 - 19, 22 - 25 ; 109, pp. 1 - 2, 4 ]. Interviews with a resident at one property along Source No. 5 revealed that Bliss Brook routinely flood s his lawn as well as adjacent properties [18, pp. 18 - 19]. Previous reports indicate that ground water flows beneath the Walton & Lonsbury Inc. property to the east - southeast, and emerges as surface water discharge at residential properties along the eastern portion of Paulette Lane [ 23, p. 47; 24, p. 46 ]. The most upstream ground water discharge to surface water is located along the wetlands associated with the Bliss Brook headwaters (PPE No. 1) [19, p.1 ]. Surface water then flows south within Bliss Brook ( toward West Street ) until Bliss Brook converges wi th the Bungay River, and continues to flow f a rther south within the Ten Mile River [19, p p . 1 - 2 ; 24, p. 46 ; 103, p. 2] . Investigations conducted by RCA , on behalf of Walton & Lonsbury Inc., have identified a dissolved chromium ground water plume associated with the Walton & Lonsbury Inc. property; and have identified ground water - to - surface - water transport as an active mechanism for contaminant transport from the Walton & Lonsbury Inc. property to residential properties along Paulette Lane , and to Bliss Brook and downstream surface water bodies [23, pp. 33 - 40, 47, 69 - 70]. Previous investigations have identified impacts to surface water and sediments along Bliss Brook associated with the Walton & Lonsbury Inc. property [23, pp. 37 - 40, 47, 69 - 70; 25, pp. 34 - 5 0 ]. Analytical sample results from a 2005 EPA Site Inspection revealed significantly elevated levels of chromium and hexavalent chromium at sediment sample locations at the identified PPE for ground water to - surface water release (8,140 mg/Kg chromium and 6.26 mg/Kg hexavalent chromium in SD - 03), throughout Bliss Brook ( including 6,260 mg/Kg chromium and 5.18 mg/Kg hexavalent chromium in SD 05), and downstream to the farthest down stream sediment sample location, near the southeastern o utlet of Mechanics Pond (1,090 mg/Kg chromium and 2.49 mg/Kg hexavalent chromium in SD - 13) [25, pp. 36 -Source Characterization Source No. 5

Walton & Lonsbury Inc. 74 HRS Documentation Record MAD001197755 5 September 2012 37, 39, 42]. In addition, analytical results of surface soil samples collected during the 2005 EPA Site Inspection from residential properties along Sou rce No. 5, adjacent to Bliss Brook, indicated significantly elevated concentrations of chromium compared to background concentrations [18, p. 13; 25, pp. 51 - 56]. A nalytical results of surface water sampling conducted by MassDEP in July 2011 indicated a con centration of 30 μg/L of hexavalent chromium in a surface water sample collected along Bliss Brook, north of the intersection of North Avenue and W est Street [ 30, pp. 3, 5, 10, 16 ]. On 26 January 2012, as part of the EPA SR , surface water sampling was conducted along Bliss Brook, southeast of the Walton & Lonsbury Inc. property, and south of the most upstream PPE for the ground water - to - surface water pathway [18, pp. 8 - 9; 28, pp. 4 - 5, 47, 66 - 67]. Four surface water samples (SW - 09, SW - 10, SW - 11, and SW - 12) were collected from Bliss Brook at locations upgradient of and within the area encompassed by contaminated Source No. 5 surface soil/source sample locations [18, pp. 11 - 12; 28, pp. 47, 66 - 67; 35, pp. 193 - 196]. Surface water sa mples were submitted to a CLP l aboratory for chromium and lead analysis under CLP SOW ISM01.3 , and to a DAS l aboratory for hexavalent chromium analysis by EPA SW - 846 Method 7196A ; and the analytical results were validated on a Tier II level according to EP A Region I Tiered Organic and Inorganic Data Validation Guidelines [18, pp. 11 - 12; 32, pp. 4, 7 - 8; 35, pp. 193 - 196; 57, pp. 1, 7 - 8; 72, pp. 5 - 8, 68 - 71; 59, pp. 1, 8 - 9]. Validated analytical results of four surface water samples (SW - 09, SW - 10, SW - 11, and SW - 12), collected at locations upgradient of and within the area encompassed by contaminated Source No. 5 surface soil/source sample locations , indicated elevated levels of total chromium (up to 247 μg/L) and hexavalent chromium (up to 96 J μg/L ) [28, pp. 47, 66 - 67; 57, pp. 1, 7 - 8; 72, pp. 5 - 8, 68 - 71; 59, pp. 1, 8 - 9]. The area of Source No. 5 was determined to be 12,333.88 ft 2 . The area includes the Source No. 5 surface soil/source sampl e locations which document significant contamination with chromium an d lead, as presented below, and the are a lying between these locations; with the exception of the areas which are covered with permanent water cover and wetlands ( 37,784.69 ft 2 ) [ 28, pp. 69, 70, 78 - 80, 83; 53, pp. 9, 10; 60, p. 9; 61, pp. 7, 8; 71 , pp. 1 - 3 , 7 ; 72, pp. 35, 38 - 41, 47 - 54, 64, 76, 78 - 81 ] . The area lying between Source No. 5 surface soil/source sample locations is inferred to be contaminated due to the likely mechanism of contaminant transport (flooding). All of the Source No. 5 surface soil/sou rce sample locations and the entirety of the area of inferred contamination lying between these locations are within an area of the same topographical elevation [ 109, pp. 1 - 2, 4 ]. In addition, Source No. 5 surface soil/source sampl e locations and the areas of inf erred contamination lying between these locations are within or in close proximity to the 100 - year flood plain, and adjacent to wetland areas and/or Bliss Brook [ 109, pp. 1 - 2, 4 ]. Based on on - site observations and an interview with a resident , the low - lying areas of residential properties along Source No. 5 , adjacent to Bliss Brook, are known or suspected to be subject to surface water flooding from Bliss Brook [18, pp. 17 - 19, 22 - 25]. Interviews with a resident at one property along Source No. 5 revealed that Bliss Brook would routinely flood the lawn on his and adjacent properties [18, pp. 18 - 19]. Therefore, based on area topography, o n - site observations, interviews , and flood plain data, the areas of inferred contamination lying between conta minated Source No. 5 surface soil/source sample locations are presumed to be contaminated due to the likely mechanism of contaminant transport (flooding) [ 18, pp. 17 - 19, 22 - 25 ; 109, pp. 1 - 2, 4]. 2.2.2 HAZARDOUS SUBSTANCES ASSOCIATED WITH THE SOURCE

- Background Concentrations: Source No. 5 is a contaminated soil source type; therefore, background surface soil samples have been utilized for comparison purposes . Between 25 January and 1 February 2012, as part of the EPA SR and in accordance with the EPA - approved January 2012 Site - Specific QAPP, background surface soil sampling activities were conducted [ 18, pp. 4, 15, 18 - 22, 25; 28, pp. 18, 27 - 28, 30 - 33, 61, 71, 76 - 77, 79, 81; 31, pp. 1, 26, 28, 33 - 34, 42 ].Source Characterization Source No. 5

Walton & Lonsbury Inc. 75 HRS Documentation Record MAD001197755 5 September 2012 Ten background surface soil samples were utilized to document natural background conditions in the local vicinity of the site. One background surface soil sample (SO - 01B) was collected from an undeveloped parcel located south of th e Walton & Lonsbury Inc. property, depicted on the City of Attleboro Tax Assessor's Map No. 59, as Lot No. 142 [12; 18, p. 4 ; 28, pp. 18, 61; 68]. Two background surface soil samples (P - 06 - SS - 07 and P - 06 - SS - 08) were collected from a residential property located south of the Walton & Lonsbury Inc. property, which is depicted on the City of Attleboro Tax Assessor's Map No. 59, as Lot No. 220 [12; 18, p. 15; 28, pp. 27 - 28, 71; 68]. One background surface soil sample (P - 14 - SS - 01) was collected from a residential property located southeast of the Walton & Lonsbu ry Inc. property, which is depicted on the City of Attleboro Tax Assessor's Map No. 49 , as Lot No. 157D [12; 18, p. 21; 28, pp. 33, 76; 69]. Two backgrou nd surface soil samples (P - 16 - SS - 03 and P - 16 - SS - 04) were collected from a residential property located southeast of the Walton & Lonsbury Inc. property, which is depicted on the City of Attleboro Tax Assessor's Map No. 49 , as Lot No. 157B [12; 18, pp. 21 - 22; 28, pp. 33, 77; 69]. One background surface soil sample (P - 18 - SS - 04) was collected from a residentia l property l ocated southeast of the Walton & Lonsbury Inc. property, which is depicted on the City of Attleboro Tax Assessor's Map No. 49 , as Lot No. 96 [12; 18, p. 18; 28, pp. 30, 79; 69]. Three background surface soil samples (P - 22 - SS - 01A, P - 22 - SS - 01B, a nd P - 22 - SS - 08) were collected from a residential property located southeast of the Walton & Lonsbury Inc. property, which is depicted on the City of At tleboro Tax Assessor's Map No. 4 9, as Lot No. 126 [12; 18, pp. 19 - 20; 28, pp. 31 - 32, 81; 69]. All backgro und surface soil sample locations are depicted in Figure 4. The 10 background surface soil samples were collected in the vicinity of the site from the same depth interval ( 0 - to 2 - f eet bgs), during the same time period , and utilizing the same collection and analytical methods as the surface soil/source samples presented as part of the Source No. 5 c haracterization [ 18, pp. 4, 15, 18 - 22, 25, 27 - 28; 28, pp. 18, 27 - 28, 30 - 36 , 61, 69 - 71, 76 - 8 1 , 83 ; 32, pp. 12 - 16; 35, pp. 20, 30, 33 - 35, 43 - 44, 9 4 , 102 - 103, 110 - 111, 117, 120 - 122, 125 - 126, 129, 137 - 138, 145, 163; 50, p. 1; 53, p. 1; 60, p. 1; 61, p. 1 ]. The 10 background surface soil samples collected as part of the EPA SR contained varying compositions of naturally occurring native materials ( i.e. , s and, silt, clay, gravel, and organic matter) [ 35, pp. 43 - 44, 9 4 , 102 - 103, 117, 137 - 138, 145, 163 ]. Background surface soil sample SO - 01B was described as moist, yellow brown, silt, some fine sand, little clay, trace medium - to - coarse gravel, trace organics, trace medium - to - coarse sand [35, p. 163]. Background surface soil sample P - 06 - SS - 07 was described as brown - to - dark brown, fine - to - coarse sand, some silt, little fine - to - medium gravel, trace organics , trace clay [35, p. 43] . Background surface soil sample P - 06 - SS - 08 was described as brown, silt and fine - to coarse sand, little fine - to - medium gravel, trace organics, trace clay [35, p. 44] . Background surface soil sample P - 14 - SS - 01 was described as dry, brown, silt , trace clay, trace fine - to - coarse san d, trace fine - to medium gravel, trace organics [35, p. 9 4 ] . Background surface soil sample P - 16 - SS - 03 was described as moist, brown - to - dark brown, clay, some silt, trace organics, trace fine gravel, trace fine - to - coarse sand [35, p. 102] . Background surfac e soil sample P - 16 - SS - 04 was described as wet, brown - to - dark brown, clay and silt, trace organics, trace fine - to - coarse sand [35, p. 103] . Background surface soil sample P - 18 - SS - 04 was described as brown, fine - to - coarse sand, little silt, little clay, trac e fine - to - medium gravel, trace organics [35, p. 117] . Background surface soil sample P - 22 - SS - 01A was described as dark brown, silt, little organics, trace fine - to - coarse sand [35, p. 137] . Background surface soil sample P - 22 - SS - 01B was described as moist, dark brown, clay and silt, little fine - to - coarse sand, trace organics [35, p. 138] . Background sur face soil sample P - 22 - SS - 08 was described as brown, fine - to - coarse sand, some silt, trace fine - to - medium gravel, trace clay, trace organics [35, p. 145] . As presented above, the 10 background surface soil samples contained varying compositions of naturally occurring native matrix materials ( i.e. , sand, silt, clay, gravel, and organic matter) , which constituted major and/or minor components of the sample s [ 35, pp. 43 - 44, 9 4 , 102 - 103, 117, 137 - 138, 145, 163 ]. Similarly, the surface soil/source samples presented as part of the Source No. 5 characterization exhibited varying compositions of the same naturally occurring native matrix materials (see Surface Soil/ Sou rce Samples presented below). Among the 10 background surface soil samples, various samples containedSource Characterization Source No. 5

Walton & Lonsbury Inc. 76 HRS Documentation Record MAD001197755 5 September 2012 native matrix material compositions that were similar to those of various source samples presented as part of the Source No. 5 c haracterization [ 35, pp. 2 0, 30, 33 - 35, 43 - 44, 9 4 , 102 - 103, 110 - 111, 117, 120 - 122, 125 - 126, 129, 137 - 138, 145, 163]. The analytical results of each Source No. 5 surface soil/source sample could be compared to the contaminant concentrations detected only in those background surface soil sample(s) which displayed the most similar matrix composition. However, for simplicity of th e HRS documentation record , and to support the case that analytical results of Source No. 5 surface soil/source samples are significantly above documented back ground concentrations, all 10 background surface soil samples are presented, and Source No. 5 surface soil/source samples were compared to the highest concentrations detected among all 10 background surface soil samples for the analytes presented. Regardless of the approach to comparison of contaminant concentrations [ i.e. , comparing Source No. 5 surface soil/source samples to only the background surface soil sample(s) that were most similar in composition, or comparing surface soil/source samples t o the highest concentrations detected among all background surface soil samples] , the surface soil/source sample analytical results for Source No. 5 indicate source contaminant concentrations significantly above background levels. Background surface soil samples SO - 01B, P - 06 - SS - 07, P - 06 - SS - 08, P - 14 - SS - 01, P - 16 - SS - 03, P - 16 - SS 04, P - 18 - SS - 04, P - 22 - SS - 01A, P - 22 - SS - 01B, and P - 22 - SS - 08 were submitted to a CLP l aboratory for chromium and lead analysis under CLP SOW ISM01.3 [ 18, pp. 27 - 28; 32, pp. 9, 12, 14 - 15; 5 0, pp. 1, 9; 60, pp. 1, 7; 61, pp. 1, 8 - 9 ]. COCs for all samples collected as part of the 2012 EPA SR and presented in this HRS d ocumentation r ecord are provided in Reference 32. The applicable COC pages for the background surface soil samples, and all corresponding sample identifiers, are provided in available COC and field notes reference documentation [18, pp. 4, 11 - 12, 15, 18 - 22, 25; 32, pp. 9, 12, 14 - 15]. In addition, all sample IDs and associated sample numbers and COC numbers are provided in a reference table [115]. The analytical data for background surface soil samples were validated on a Tier II level according to EPA Region I Tiered Organic and Inorganic Data Validation Guidelines [ 50, pp. 1, 3; 60, pp. 1, 3; 61, pp. 1, 3 ]. I n addition, the validation was conducted independently by designated chemists who were not involved in the sample collection and HRS evaluation [ 35, pp. 43 - 44, 94, 102 - 103, 117, 137 - 138, 145, 163; 50, pp. 1, 3; 60, pp. 1, 3; 61, pp. 1, 3 ]. As part of this H RS documentation record and the evaluation of background concentrations, the following hazardous substances in background surface soil samples are presented: chromium and lead. A mong the 10 background surface soil samples , chromium was detected at a maximum concentration of 14.1 mg/Kg in sample P - 14 - SS - 01; and lead was detected at a maximum concentration of 76.4 mg/Kg in sample P - 22 - SS - 01A [ 18, pp. 4, 11 - 12, 15, 18 - 22, 25, 27 - 28; 28, pp. 61, 71, 76, 77, 79, 81; 50, p. 9; 60, p. 7; 61, pp. 8, 9; 72, pp. 2 3 - 28 , 30 - 31, 72, 74, 81, 82 , 84] . Table 27 - Hazardous Substances Associated with Background Samples Sample ID Sample Type Date Hazardous Substance Hazardous Substance Concentration Sample Adjusted

CRQL Reference SO - 01B Surface Soil 25 Jan. 2012 Chromium 10.7 mg/Kg 0.87 mg/Kg 18, pp. 4, 11 - 12, 25, 27 - 28; 28, p. 61 ; 50, p. 9 ; 72, pp. 1, 32, 72 Lead 10.1 mg/Kg 0.87 mg/Kg P - 06 - SS - 07 Surface Soil 31 Jan. 2012 Chromium 12.5 mg/Kg 0.98 mg/Kg 18, pp. 15, 27 - 28; 28, p. 71 ; 60, p. 7 ; 72, pp. 1, 2 3 , 74 Lead 23.4 mg/Kg 0.98 mg/KgSource Characterization Source No. 5

Walton & Lonsbury Inc. 77 HRS Documentation Record MAD001197755 5 September 2012 Table 27 - Hazardous Substances Associated with Background Samples Sample ID Sample Type Date Hazardous Substance Hazardous Substance Concentration Sample Adjusted

CRQL Reference P - 06 - SS - 08 Surface Soil 31 Jan. 2012 Chromium 10.3 mg/Kg 1.05 mg/Kg 18, pp. 15, 27 - 28; 28, p. 71 ; 60, p. 7 ; 72, pp. 1, 24, 74 Lead 31.4 mg/Kg 1.05 mg/Kg P - 14 - SS - 01 Surface Soil 1 Feb. 2012 Chromium 14.1 mg/Kg 1.41 mg/Kg 18, pp. 21, 27 - 28; 28, p. 76 ; 61, p. 8 ; 72, pp. 1, 25, 81 Lead 30.4 mg/Kg 1.41 mg/Kg P - 16 - SS - 03 Surface Soil 1 Feb. 2012 Chromium 12.0 mg/Kg 1.60 mg/Kg 18, pp. 21, 27 - 28; 28, p. 77 ; 61, p. 9 ; 72, pp. 1, 26, 81 Lead 59.9 mg/Kg 1.60 mg/Kg P - 16 - SS - 04 Surface Soil 1 Feb. 2012 Chromium 13.3 mg/Kg 1.34 mg/Kg 18, pp. 22, 27 - 28; 28, p. 77 ; 61, p. 9 ; 72, pp. 1, 27, 81 Lead 66.8 mg/Kg 1.34 mg/Kg P - 18 - SS - 04 Surface Soil 1 Feb. 2012 Chromium 11.0 mg/Kg 1.12 mg/Kg 18, pp. 18, 27 - 28; 28, p. 79 ; 61, p. 9 ; 72, pp. 1, 28, 81 Lead 29.4 mg/Kg 1.12 mg/Kg P - 22 - SS - 01A Surface Soil 1 Feb. 2012 Chromium 10.4 mg/Kg 1.67 mg/Kg 18, pp. 19, 27 - 28; 28, p. 81 ; 61, p. 9 ; 72, pp. 1, 81 , 84 Lead 76.4 mg/Kg 1.67 mg/Kg P - 22 - SS - 01B Surface Soil 1 Feb. 2012 Chromium 9.7 mg/Kg 1.44 mg/Kg 18, pp. 19, 27 - 28; 28, p. 81 ; 61, p. 9 ; 72, pp. 1, 30, 82 Lead 38.9 mg/Kg 1.44 mg/Kg P - 22 - SS - 08 Surface Soil 1 Feb. 2012 Chromium 10.0 mg/Kg 1.15 mg/Kg 18, pp. 20, 27 - 28; 28, p. 81 ; 61, p. 9 ; 72, pp. 1, 31, 82 ; 61, p. 9 Lead 51.5 mg/Kg 1.15 mg/Kg Jan. = January CRQL = Contract Required Quantitation Limit Feb. = February mg/Kg = Milligrams per Kilogram

- Source Samples: On 1 and 2 February 2012, as part of the EPA SR and in accordance with the EPA - approved January 2012 Site - Specific QAPP , surface soil/source sampling activities for Source No. 5 were conducted [ 18, pp. 22, 27 - 28; 28, pp. 30 - 31, 33 - 36, 69 - 70, 78 - 80, 83 ; 31, pp. 1, 26, 32, 40 - 43 ]. As part of the Source No. 5 characterization, 14 surface soil/source samples were collected from residential properties located southeast of the Walton & Lonsbury Inc. property (samples P - 03 - SS - 05, P 05 - SS - 01, P - 05 - SS - 04, P - 05 - SS - 05, P - 05 - SS - 06, P - 17 - SS - 07A, P - 17 - SS - 07B, P - 18 - SS - 07, P - 18 - SS - 08, P - 18 - SS - 09, P - 19 - SS - 03, P - 20 - SS - 01, P - 20 - SS - 04A, and P - 31 - SS - 04A) [18, pp. 18 - 19 , 21 - 25, 27 - 28; 28, pp. 30 - 31, 33 - 36, 69 - 70, 78 - 80, 83]. Surface soil/source samples utilized to characterize Source No. 5 include the following: one surface soil/source sample (P - 03 - SS - 05) collected fro m a property designated as “P - 03 ”, depicted on the City of Attleboro Tax Assessor's M ap No. 49, as Lot No. 112 ; three surface soil/source samples (P - 05 - SS - 01, P - 05 - SS - 04, and P - 05 - SS - 05) collected fro m a property designated asSource Characterization Source No. 5

Walton & Lonsbury Inc. 78 HRS Documentation Record MAD001197755 5 September 2012 “P - 05 ”, depicted on the City of A ttleboro Tax Assessor's M ap No. 49, as Lot No. 109 ; one surface soil/source sample (P - 05 - SS - 06) collected fro m a property designated as “P - 05 ”, depicted on the City of Attleboro Tax Assessor's M ap No. 49, as Lot No. 110 ; two surface soil/source samples (P - 17 - SS - 07A and P - 17 - SS - 07B) collected fro m a property designated as “P - 17 ”, depicted on the City of Attleboro Tax Assessor's Map No. 49, as Lot No. 94 ; three surface soil/source samples (P - 18 - SS - 07, P - 18 - SS - 08, and P 18 - SS - 09) collected from a property desi gnated as “P - 18”, depicted on the City of Attleboro Tax Assessor's Map No. 49, as Lot No. 96; one surface soil/source sample (P - 19 - SS - 03) collected from a property designated as “P - 1 9 ”, depicted on the City of Attleboro Tax Assessor's Map No. 49, as Lot No . 9 7A ; and three surface soil/source samples [P - 20 - SS - 01 and P - 20 - SS - 04A/P - 31 - SS - 04A (field duplicate)] collected from a property designated as “P - 20 ”, depicted on the City of Attleboro Tax Assessor's Map No. 49, as Lot No. 9 7 [28, pp. 30 - 31, 33 - 36, 69 - 70, 78 - 80, 83; 68; 69]. Surface soil/source samples P - 17 - SS 07A and P - 17 - SS - 07B represent separate depth intervals at the same location; otherwise, all sample s listed above (excluding field duplicates) represent discrete sample locations [18, p. 23 ; 28, pp. 30 - 31, 33 - 36, 69 - 70, 78 - 80, 83]. All property designations ( e.g. , “P - 01”, “P - 02”, etc. ) were assigned during the 2012 EPA SR , and are associated with the corresponding identifiers for soil samples collected from each property ( e.g. , P - 01 - SS - ##, P - 02 - SS - ##, etc. ) [18, pp. 13 - 14]. All surface soil/source samples collected from the Source No. 5 as part of the 2012 EPA SR were collected from depths less than 2 feet bgs [ 35, pp. 20, 30, 33 - 35, 110 - 111, 120 - 122, 125 - 126, 129 ]. Locations of surface soil /source samples collected from the Source No. 5 are depicted in Figure 9. Surface soil/source samples collected from Source No. 5 were of similar composition to the native materials described in the background surface soil samples presented for Source No. 5. Surface soil/source sample P - 03 - SS - 05 was described as wet, yellow brown - to - brown, fine - to - coarse sand, trace clay, trace silt, trace fine gravel, trace organics [35, p. 20] . Surface soil/source sample P - 05 - SS - 01 was des cribed as saturated, dark brown, clay and silt, trace fine - to - coarse sand, trace organics, trace fine - to medium gravel [35, p. 30] . Surface soil/source sample P - 05 - SS - 04 was described as wet, dark brown, silt and fine - to - coarse sand, little clay, trace org anics, trace fine gravel [35, p. 33] . Surface soil/source sample P - 05 - SS - 05 was described as dry, dark brown, silt, some fine - to - coarse sand, trace organics, trace fine - to medium gravel, trace debris (plastic wrapper, paper) [35, p. 34] . Surface soil/sourc e sample P - 05 - SS - 06 was described as dry, dark brown, silt, little fine - to - coarse sand, little organics, trace clay [35, p. 35] . Surface soil/source sample P - 17 - SS - 07A was described as moist, dark brown, silt and clay, trace fine - to coarse sand, trace fine gravel, trace organics [35, p. 110] . Surface soil/source sample P - 17 - SS - 07B was described as saturated, dark brown, silt and clay, little fine - to - coarse sand, trace organics [35, p. 111] . Surface soil/source sample P - 18 - SS - 07 was described as wet, dark br own, silt and clay, little organics, trace fine - to - coarse sand, trace fine - to - medium gravel [35, p. 120] . Surface soil/source sample P - 18 - SS 08 was described as moist, dark brown, silt and clay, t race fine - to - coarse sand, trace organics, trace fine gravel [35, p. 121] . Surface soil/source sample P - 18 - SS - 09 was described as saturated, dark brown, silt and clay, trace fine - to - coarse sand, trace organics, trace fine gravel [35, p. 122] . Surface soil/source sample P - 19 - SS - 03 was described as dry, dark brown, si lt, little clay, trace fine - to - coarse sand, trace organics, trace fine gravel [35, p. 125] . Surface soil/source sample P - 20 - SS - 01 was described as brown, fine - to - coarse sand, little silt, trace fine - to - medium gravel, trace clay, trace organics [35, p. 126] . Surface soil/source samples P - 20 - SS - 04A and field duplicate P - 31 - SS - 04A were described as brown - to - dark brown, silt, trace fine - to - coarse sand, trace organics, trace fine gravel, trace debris (cinder ash) [35, p. 129] . The 14 surface soil/source sample s (P - 03 - SS - 05, P - 05 - SS - 01, P - 05 - SS - 04, P - 05 - SS - 05, P - 05 - SS - 06, P 17 - SS - 07A, P - 17 - SS - 07B, P - 18 - SS - 07, P - 18 - SS - 08, P - 18 - SS - 09, P - 19 - SS - 03, P - 20 - SS - 01, P - 20 - SS - 04A, and P - 31 - SS - 04A) were sub mitted to a CLP l aboratory for chromium and lead analysis under CLP S OW ISM01.3 [ 18, pp. 27 - 28; 32, pp. 13 - 14, 16; 53, pp. 1, 9 - 10; 60, pp. 1, 9; 61, pp. 1, 7 - 8 ]. COCs for all samples collected as part of the 2012 EPA SR and presented in this HRS d ocumentation r ecord are provided in Reference 32. The applicable COC pages for the Source No. 5 soil/source samples, and allSource Characterization Source No. 5

Walton & Lonsbury Inc. 79 HRS Documentation Record MAD001197755 5 September 2012 corresponding sample identifiers, are provided in available COC and field notes reference documentation [18, pp. 18 - 19, 21 - 25; 32, pp. 13 - 14, 16] . In addition, all sample IDs and associated sample numbers and COC numbers are provided in a reference table [115]. The analytical data for Source No. 5 surface soil/source samples were validated on a Tier II level according to EPA Region I Tiered Organic and Inorganic Data Validation Guidelines [ 53, pp. 1, 4; 60, pp. 1, 3; 61, pp. 1, 3 ]. I n addition, the validation was conducted independently by designated chemists who were not involved in the sample collection and HRS evaluation [ 35, pp. 20, 30, 33 - 35, 1 10 - 111, 120 - 122, 125 - 126, 129; 53, pp. 1, 4; 60, pp. 1, 3; 61, pp. 1, 3 ]. Among the 14 surface soil/source samples, chromium was detected at a maximum concentration of 2,020 mg/Kg in surface soil/source sample P - 18 - SS - 07 , and lead was detected at a maximum concentration of 359 mg/Kg in surface soil/source sample P - 19 - SS - 03 [ 18, pp. 18 - 19, 21 - 25, 27 - 28; 28, pp. 69, 70, 78 - 80, 83; 53, pp. 9, 10; 60, p. 9; 61, pp. 7, 8; 72, pp. 35, 38 - 41, 47 - 54, 64, 76, 78 - 81 ]. Based on chemical analysis of surface soil/source samples collected as part of the EPA SR , Source No. 5 has been documented to contain chromium and lead , which are defined as hazardous substances according to the HRS Rule [1, p. 51586; 7, pp. 7, 14 - 15; 8, pp. 52 - 56; 28, pp. 69, 70, 78 - 80, 83; 53, pp. 9, 10; 60, p. 9; 61, pp. 7, 8; 72, pp. 35, 38 - 41, 47 - 54, 64, 76, 78 - 81 ]. The hazardous substances chromi um and lead were detected in Source No. 5 surface soil/source samples at concentrations significantly above background concentrations [28, pp. 69, 70, 78 - 80, 83; 53, pp. 9, 10; 60, p. 9; 61, pp. 7, 8; 72, pp. 35, 38 - 41, 47 - 54, 64, 76, 78 - 81]. Therefore , chromium and lead are considered to be associated with Source No. 5 [1, p. 51588, Section 2.2.2]. Only contaminated surface soil /source samples which contain hazardous substance concentrations greater than or equal to three times background levels are p resent ed for the Source No. 5 characterization. Per the HRS, contaminated surface soil/source samples with hazardous substance concentrations above background levels, but less than three times background levels, could be presented as part of the source cha racterization. However, for the simplicity of this documentation record, and to identify a significant increase in source hazardous substance concentrations compared to background levels , only the contaminated surface soil /source samples with hazardous sub stance concentrations greater than or equal to three times background levels are presented . If all contaminated surface soil/source samples with hazardous substance concentrations above background levels were included in the source characterization, the ex tent of contamination for Source No. 5 would be larger than the area delineated by the selection of surface soil/ source samples that are presented. Table 28 - Hazardous Substances Associated with Source No. 5 Sample ID Sample Type Date Hazardous Substance Hazardous Substance Concentration Sample Adjusted

CRQL Reference P - 03 - SS - 05 Surface Soil /Source 1 Feb. 2012 Chromium 55.6 mg/Kg 1.06 mg/Kg 18, pp. 21, 27 - 28; 28, p. 69 ; 60, p. 9 ; 72, pp. 1, 35, 76 P - 05 - SS - 01 Surface Soil/Source 1 Feb. 2012 Chromium 261 mg/Kg 1.41 mg/Kg 18, pp. 22, 27 - 28; 28, p. 70 ; 61, p. 7 ; 72, pp. 1, 38, 80 P - 05 - SS - 04 Surface Soil/Source 1 Feb. 2012 Chromium 258 mg/Kg 1.18 mg/Kg 18, pp. 22, 27 - 28; 28, p.70 ; 61, p. 7 ; 72, pp. 1, 39, 80Source Characterization Source No. 5

Walton & Lonsbury Inc. 80 HRS Documentation Record MAD001197755 5 September 2012 Table 28 - Hazardous Substances Associated with Source No. 5 Sample ID Sample Type Date Hazardous Substance Hazardous Substance Concentration Sample Adjusted

CRQL Reference P - 05 - SS - 05 Surface Soil/Source 1 Feb. 2012 Chromium 104 mg/Kg 1.07 mg/Kg 18, pp. 22, 27 - 28; 28, p. 70 ; 61, p. 7 ; 72, pp. 1, 40, 80 P - 05 - SS - 06 Surface Soil/Source 1 Feb. 2012 Chromium 234 mg/Kg 1.28 mg/Kg 18, pp. 22, 27 - 28; 28, p. 70 ; 61, p. 7 ; 72, pp. 1, 41, 80 P - 17 - SS - 07A Surface Soil/Source 2 Feb. 2012 Chromium 857 mg/Kg 2.08 mg/Kg 18, pp. 23, 27 - 28; 28, p. 78 ; 53, p. 9 ; 72, pp. 1, 47, 78 ; 53, p. 9 P - 17 - SS - 07B Surface Soil/Source 2 Feb. 2012 Chromium 72.2 mg/Kg 1.26 mg/Kg 18, pp. 23, 27 - 28; 28, p. 78 ; 53, p. 9 ; 72, pp. 1, 48, 78 P - 18 - SS - 07 Surface Soil/Source 1 Feb. 2012 Chromium 2,020 mg/Kg 2.01 mg/Kg 18, pp. 18, 27 - 28; 28, p. 79 ; 61, p. 8 ; 72, pp. 1, 49, 81 P - 18 - SS - 08 Surface Soil/Source 2 Feb. 2012 Chromium 1,000 mg/Kg 1.74 mg/Kg 18, pp. 25, 27 - 28; 28, p. 79 ; 53, p. 9 ; 72, pp. 1, 50, 78 P - 18 - SS - 09 Surface Soil/Source 2 Feb. 2012 Chromium 270 mg/Kg 1.18 mg/Kg 18, pp. 25, 27 - 28; 28, p. 79 ; 53, p. 9 ; 72, pp. 1, 51, 78 P - 19 - SS - 03 Surface Soil/Source 1 Feb. 2012 Chromium 45.0 mg/Kg 1.44 mg/Kg 18, pp. 19, 27 - 28; 28, p. 79 ; 61, p. 7 ; 72, pp. 1, 52, 80 Lead 359 mg/Kg 1.44 mg/Kg P - 20 - SS - 01 Surface Soil/Source 1 Feb. 2012 Lead 326 mg/Kg 1.46 mg/Kg 18, pp. 18, 27 - 28; 28, p. 80 ; 61, p. 7 ; 72, pp. 1, 53, 80 P - 20 - SS - 04A Surface Soil/Source 2 Feb. 2012 Chromium 64.5 mg/Kg 1.49 mg/Kg 18, pp. 24, 27 - 28; 28, p. 80 ; 53, p. 10 ; 72, pp. 1, 54, 78 Lead 311 mg/Kg 1.49 mg/Kg P - 31 - SS - 04A Surface Soil/Source 2 Feb. 2012 Chromium 67.8 mg/Kg 1.60 mg/Kg 18, pp. 24, 27 - 28; 28, p. 83 ; 53, p. 10 ; 72, pp. 1, 64, 79 Lead 304 mg/Kg 1.60 mg/Kg Feb. = February CRQL = Contract Required Quantitation Limit. mg/Kg = Milligrams per K ilogram List of Hazardous Substances Associated with Source Chromium LeadSource Characterization Source No. 5

Walton & Lonsbury Inc. 81 HRS Documentation Record MAD001197755 5 September 2012 2.2.3 HAZARDOUS SUBSTANCES AVAILABLE TO A PATHWAY The area of Source No. 5 (12,333.88 ft 2 ) includes the surface soil/source sample locations which document significant contamination with chromium and lead, and the are a lying between these locations; with the exception of the areas which are covered with permanent water cover or wetlands [ 28, pp. 69, 70, 78 - 80, 83; 53, pp. 9, 10; 60, p. 9; 61, pp. 7, 8; 71 , pp. 1 - 3 , 7 ; 72, pp. 35, 38 - 41, 47 - 54, 64, 76, 78 - 81 ]. The total area between contaminated surface soil/source samples , including the area of essentially impermeable cover , was determined to be 50,118.57 ft 2 [71 , pp. 1 - 3 ]. B ased on on - site observations , wetland delineation activities, and an interpretation of aerial imagery using GIS software , t he area covered with permanent water cover or wetlands was determined to be 37,78 4.69 ft 2 [ 71 , pp. 1 - 3 ]. Therefore, based on analysis of GPS coordinates recorded for the 14 surface soil/source sample locations presented above, analysis and interpretation of aerial photographs of the area, and on - site observations, the area of Source No. 5 not covered by impermeable cover is approximately 12,333.88 ft 2 ( 50,118.57 ft 2

- 37,784.69 ft 2 = 12,333.88 ft 2 ) [ 71 , pp. 1 - 3 ]. On - site observations indicate that no portion of Source No. 5 has a maintained engineered cover or complete run - on or runoff control management systems [ 18 , p. 28 ]. Th erefore, Source No. 5 does not have full containment, and the source yields a containment v alue of 10 for the overland flow component of the Surface Water pathway [1, p. 51609 (Table 4 - 2)]. Tabl e 29 - Hazardous Substances Available to Pathways Containment Description Containment Factor References Release via overland migration and/or flood : Based on the lack of a maintained engineered cover, and any complete run on and runoff control management systems, a Containment Factor Value of 10 has been assigned for release via overland migration and/or flood for Source No. 5 . 10 1, p. 51609 (Table 4 - 2) ; 18 , p. 28; 71 , pp. 1 - 3 2.4.2 HAZARDOUS WASTE QUANTITY 2.4.2.1 Hazardous Waste Quantity The Hazardous Waste Quantity for Source No. 5 was assigned based on the Area Assigned Value of a “contaminated soil” source type [1, p. 51591 (Table 2 - 5, Section 2.4.2.1. 4 )]. The Hazardous Constituent Quantity, Hazardous Wastestream Quantity, and Volume Assigned Values wer e not evaluated for Source No. 5 because insufficient information was available , as described in the sections below [1, p. 51591 (Table 2 - 5, Sections 2.4.2.1.1 , 2.4.2.1.2 and 2.4.2.1. 3 )]. 2.4.2.1.1 Hazardous Constituent Quantity Description The H azardous C onstituent Q uantity for Source No. 5 could not be adequately determined according to the HRS Rule requirements; that is, the total mass of all CERCLA hazardous substances in the source and releases from the source is not known and cannot be estimated with reasonable confidence [1, pp. 51590 - 51591 (Section 2.4.2.1.1)]. Insufficien t historical and current data (m anifests, PRP records, State rec ords, permits, w aste concentration data, etc.) are available to adequately calculate the total mass of all CERCLA hazardous substances in the source and the associated releases from the source. Therefore, thereSource Characterization Source No. 5

Walton & Lonsbury Inc. 82 HRS Documentation Record MAD001197755 5 September 2012 is insufficient information to evaluate the associated releases from the source to calculate the H azardous C onstituent Q uantity for Source No. 5 with reasonable confidence. Table 30 – Hazardous Constituent Quantity Hazardous Substance Constituent Quantity (pounds) References NS (insufficient information) Sum (pounds): Hazardous Constituent Quantity Assigned Value: NS 2.4.2.1.2 Hazardous Wastestream Quantity Description The H azardous W astestream Q uantity for Source No. 5 could not be adequately determined according to the HRS Rule requirements; that is, the total mass of all hazardous wastestreams and CERCLA pollutants and contaminants for the source and releases from the source is not known and cannot be estimated with r easonable confidence [1, p. 51591 (Section 2.4.2.1.2)]. Insufficien t historical and current data (m anifests, PRP records, State records, permits, waste concentration data, a nnual reports, etc.) are available to adequately calculate the total mass of all ha zardous wastestreams and CERCLA pollutants and contaminants for the source and the associated releases from the source. Therefore, there is insufficient information to adequately calculate or extrapolate the H azardous W astestream Q uantity for Source No. 5 with reasonable confidence. Tabl e 31 – Hazardous Wastestream Quantity Hazardous Wastestream Wastestream Quantity (pounds) References NS (insufficient information) Sum (pounds): Sum of Wastestream Quantity/5,000 (1, p. 51591, Table 2 - 5): Hazardous Wastestream Quantity Assigned Value : NS 2.4.2.1.3 Volume Description The volume for Source No. 5 could not be adequately determined according to the HRS Rule requirements because insufficient historical and current waste sampling data are available to adequately calculate the volume of the source with reasonable confidence [1, p. 51591 (Section 2.4.2.1.3)]. Insufficient historical or current sampling data are available to adequately estimate the depth of waste material within the source. Therefore, ther e is insufficient information to adequately calculate or estimate the volume for Source No. 5 with reasonable confidence.Source Characterization Source No. 5

Walton & Lonsbury Inc. 83 HRS Documentation Record MAD001197755 5 September 2012 Table 32 – Volume Source Type Description (# drums or dimensions) Units (yd 3 ) References NS (insufficient information) Sum (yd 3 ): Equation for Assigning Value (1, p. 51591, Table 2 - 5): Volume Assigned Value: NS 2.4.2.1.4 Area Description The area of Source No. 5 includes the surface soil/source sample locations which document contamination with chromium and lead, and the are a lying between these locations; with the exception of the areas which are covered with permanent water cover or wetlands [ 28, pp. 69, 70, 7 8 - 80, 83; 53, pp. 9, 10; 60, p. 9; 61, pp. 7, 8; 71 , pp. 1 - 3 , 7 ; 72, pp. 35, 38 - 41, 47 - 54, 64, 76, 78 - 81 ]. The area of Source No. 5 was determined by connecting 10 contaminated surface soil sample GPS locations [ P - 03 - SS - 05, P - 05 - SS - 06, P - 05 - SS - 05, P - 20 - SS - 04A/P - 31 - SS - 04A (field duplicate), P - 20 - SS - 01, P - 19 - SS - 03, P - 18 - SS - 07, P - 18 - SS - 0 8 , P - 24 - SS - 04, and P - 17 - SS - 07A/B] with straight lines, using GIS software [ 71 , pp. 1 - 3 ]. The total area between contaminated surface soil/source sample locations, including the area of permanent water cover or wetlands , was determined to be 50,118.57 ft 2 [71 , pp. 1 - 3 ]. B ased on on - site observations, interpretation of aerial imagery using GIS software , and the results of wetland delineation activities, t he area covered wi th permanent water cover or wetlands was determined to 37,784.69 ft 2 [ 71, pp. 1 - 3 ]. Source No. 5 therefore comprises 12,333.88 ft 2 of contaminated soil ( 50,118.57 ft 2

- 37,784.69 ft 2 = 12,333.88 ft 2 ). Table 33 – Area Source Type Units (ft 2 ) References Contaminated Soil 12,333.88 71 , pp. 1 - 3 ft 2 = Square Feet. The area of a “contaminated soil” source, in ft 2 , is divided by 34,000 to assign a Hazardous Waste Quantity to the source [1, p. 51591, Table 2 - 5]. Sum (ft 2 ): 12,333.88 Equation for Assigning Value (1, p. 51591, Table 2 - 5): 12,333.88 ft 2 ÷ 34,000 = 0.36 Area Assigned Value: 0.36Source Characterization Source No. 5

Walton & Lonsbury Inc. 84 HRS Documentation Record MAD001197755 5 September 2012 2.4.2.1.5 Source Hazardous Waste Quantity Value The Hazardous Waste Quantity Value for Source No. 5 was assigned based on the Area Assigned Value ( 1.2 1 ) [1, p. 51591, Table 2 - 5]. The Hazardous Constituent Quantity, Hazardous Wastestream Quantity, and Volume Assigned Values wer e not evaluated for Source No. 5 because insufficient information was available [1, p. 51591, Sections 2.4.2.1.1, 2.4.2.1.2, 2.4. 2.1.3]. Highest HWQ value assigned from Ref. 1, Table 2 - 5: 0.36Source Characterization Source No. 6

Walton & Lonsbury Inc. 85 HRS Documentation Record MAD001197755 5 September 2012 2.2 SOURCE CHARACTERIZATION 2.2.1 SOURCE IDENTIFICATION Name of S ource : Contaminated Soil Area C Number of S ource : Source No. 6 Source Type : Contaminated Soil Description and Location of Source : Contaminated Soil Area C ( Contaminated Soil - Source No. 6 ) comprises 4,350.89 ft 2 ( 0.10 acres ) located on portion s of four properties located southeast of the Walton & Lonsbury Inc. property (see Figure 10) [10; 12; 65; 66; 71 , pp. 1, 3 - 4, 8 ]. These four properties are depicted on the City of Attleboro, MA Tax Assessor’s Map No. 49, as Lot Nos. 124, 125, 125A, and 126 [12; 69]. The geographic coordin ates of Source No. 6 , as measured from its approximate center, are 41° 57 ′ 6.8 ′′ north latitude and 71° 17 ′ 43.2 ′′ west longitude [11; 71 , pp. 1, 3 - 4 ]. Source No. 6 is located southeast of the Walton & Lonsbury Inc. property, south of West Street, along portions of residential properties adjacent to Bliss Brook [18, pp. 20 - 21 , 24 ; 28, pp. 32 - 33 , 36, 80 - 82 ]. Source No. 6 is located within the 100 - year flood plain and is downgradient of the ground water - to surface water PPE (PPE No. 1 ) located along Bliss Brook (see Figures 2 and 3) [109, pp. 1 - 2 , 4 ]. As part of the 2012 EPA SR , Source No. 6 surface soil/source samples were collected from low - lying areas on residential properties , adjacent to Bliss Brook [18, pp. 20 - 21 , 24 ]. Based on site topography , flood zone data, and on - site observations, the low - lying areas of residential properties along Source No. 6, adjacent to Bliss Brook, are inferred to be subject to surface water flooding from Bliss Brook [18, pp. 20 - 21 , 24 ; 109, pp. 1 - 2, 4 ]. Previous reports indicate that ground water flows beneath the Walton & Lonsbury Inc. property to the east - southeast, and emerges as surface water discharge at residential properties along the eastern portion of Paulette Lane [23, p. 47; 24, p. 46 ]. The most upstream ground water discharge to surface water is located along the wetlands asso ciated with the Bliss Brook headwaters (PPE No. 1) [19, p.1]. Surface water then flows south within Bliss Brook (toward West Street) until Bliss Brook converges with the Bungay River, and continues to flow f a rther south within the Ten Mile River [19, pp. 1 - 2; 24, p. 46 ; 103, p. 2] . Investigations conducted by RCA , on behalf of Walton & Lonsbury Inc., have identified a dissolved chromium ground water plume associated with the Walton & Lonsbury Inc. property; and have identified ground water - to - surface - water transport as an active mechanism for contaminant transport from the Walton & Lonsbury Inc. property to residential properties along Paulette Lane , and to Bliss Brook and downstream surface water bodies [23 , pp. 33 - 40, 47, 69 - 70]. Previous investigations have identified impacts to surface water and sediments along Bliss Brook associated with the Walton & Lonsbury Inc. property [23, pp. 3 7 - 40, 47, 69 - 70; 25, pp. 34 - 5 0 ]. Analytical sample results from a 20 05 EPA Site Inspection revealed significantly elevated levels of chromium and hexavalent chromium at sediment sample locations at the identified PPE for ground water to - surface water release (8,140 mg/Kg chromium and 6.26 mg/Kg hexavalent chromium in SD - 0 3), throughout Bliss Brook ( including 6,260 mg/Kg chromium and 5.18 mg/Kg hexavalent chromium in SD 05), and downstream to the farthest down stream sediment sample location, near the southeastern outlet of Mechanics Pond (1,090 mg/Kg chromium and 2.49 mg/K g hexavalent chromium in SD - 13) [25, pp. 36 - 37, 39, 42]. In addition, analytical results of a surface soil sample collected during the 2005 EPA Site Inspection from a low - lying, flood - prone area on a residential propert y along Source No. 6, adjacent toSource Characterization Source No. 6

Walton & Lonsbury Inc. 86 HRS Documentation Record MAD001197755 5 September 2012 Bl iss Brook, indicated a significantly elevated concentration of chromium (1,690 mg/Kg) compared to background concentrations [ 18, p. 13; 25, pp. 51 - 5 6]. A nalytical results of surface water sampling conducted by MassDEP in July 2011 indicated a concentration of 30 μg/L of hexavalent chromium in a surface water sample collected along Bliss Brook, north of the intersection of North Avenue and West Street [30, pp. 3, 5, 10, 16]. On 26 January 2012, as part of the EPA SR , surface water sampling was conducted al ong Bliss Brook, southeast of the Walton & Lonsbury Inc. property, and south of the most upstream PPE for the ground water - to - surface water pathway [18, pp. 8 - 9; 28, pp. 4 - 5, 47, 66 - 67]. Four surface water samples (SW - 09, SW - 10, SW - 11, and SW - 12) were collected from Bliss Brook at locations upgradient of and within the area encompassed by contaminated Source No. 6 surface soi l/source sample locations [18, pp. 11 - 12; 28, pp. 47, 66 - 67; 35, pp. 193 - 196]. Surface water samples were submitted to a CLP laboratory for chromium and lead analysis under CLP SOW ISM01.3, and to a DAS laboratory for hexavalent chromium analysis by EPA SW - 846 Method 7196A; and the analytical results were validated on a Tier II level according to EPA Region I Tiered Organic and Inorganic Data Validation Guidelines [18, pp. 11 - 12; 32, pp. 4, 7 - 8; 35, pp. 193 - 196; 57, pp. 1, 7 - 8; 72, pp. 5 - 8, 68 - 71; 59, pp. 1 , 8 - 9]. Validated analytical results of four surface water samples (SW - 09, SW - 10, SW - 11, and SW - 12), collected at locations upgradient of and within the area encompassed by contaminated Source No. 6 surface soil/source sample locations , indicated elevated levels of total chromium (up to 247 μg/L) and hexavalent chromium (up to 96 J μg/L ) [28, pp. 47, 66 - 67; 57, pp. 1, 7 - 8; 59, pp. 1, 8 - 9 ; 72, pp. 5 - 8, 68 - 71]. The area of Source No. 6 was determined to be 4,350.89 ft 2 . The area includes the Source No. 6 surface soil/source sample locations which document observed contamination with chromium and lead, as presented below, and the are a lying between these locations; with the exception of areas which are covered with permanent water cover and wet lands ( 6,185.54 ft 2 ) [ 28, pp. 80 - 82; 53, p. 10; 60, p p. 8, 9; 61, p. 7; 7 1 , pp. 1, 3 - 4, 8 ; 72 , pp. 55 - 61, 75, 79, 80 ]. The area lying between Source No. 6 surface soil/source sample locations is inferred to be contaminated due to the likely mechanism of c ontaminant transport (flooding). All of the Source No. 6 surface soil/source sample locations and the entirety of the area of inferred contamination lying between these locations are within an area of the same topographical elevation [109, pp. 1 - 2, 4]. In addition, Source No. 6 surface soil/source sample locations and the areas of inferred contamination lying between these locations are within or in close proximity to the 100 - year flood plain, and adjacent to wetland areas and/or Bliss Brook [109, pp. 1 - 2, 4]. Therefore, based on area topography and flood plain data, the areas of inferred contamination lying between Source No. 6 surface soil/source sample locations are presumed to be contaminated due to the likely mechanism of contaminant transport (floodin g) [18, pp. 17 - 19, 22 - 25; 109, pp. 1 - 2, 4]. 2.2.2 HAZARDOUS SUBSTANCES ASSOCIATED WITH THE SOURCE

- Background Concentrations: Source No. 6 is a contaminated soil source type; therefore, background surface soil samples have been utilized for comparison purposes . Between 25 January and 1 February 2012, as part of the EPA SR and in accordance with the EPA - approved January 2012 Site - Specific QAPP, background surface soil sampling activities were conducted [ 18, pp. 4, 15, 18 - 22, 25; 28, pp. 18, 27 - 28, 30 - 33, 61, 71, 76 - 77, 79 , 81; 31, pp. 1, 26, 28, 33 - 34, 42 ]. Ten background surface soil samples were utilized to document natural background conditions in the local vicinity of the site. One background surface soil sample (SO - 01B) was collected from an u ndeveloped parcel located south of th e Walton & Lonsbury Inc. property, depicted on the City of Attleboro Tax Assessor's Map No. 59, as Lot No. 142 [12; 18, p. 4 ; 28, pp. 18, 61; 68]. Two background surface soil samples (P - 06 - SS - 07 and P - 06 - SS - 08) were col lected from a residential property locatedSource Characterization Source No. 6

Walton & Lonsbury Inc. 87 HRS Documentation Record MAD001197755 5 September 2012 south of the Walton & Lonsbury Inc. property, which is depicted on the City of Attleboro Tax Assessor's Map No. 59, as Lot No. 220 [12; 18, p. 15; 28, pp. 27 - 28, 71; 68]. One background surface soil sample (P - 14 - S S - 01) was collected from a residential property located southeast of the Walton & Lonsbury Inc. property, which is depicted on the City of Attleboro Tax Assessor's Map No. 49 , as Lot No. 157D [12; 18, p. 21; 28, pp. 33, 76; 69]. Two background surface soil samples (P - 16 - SS - 03 and P - 16 - SS - 04) were collected from a residential property located southeast of the Walton & Lonsbury Inc. property, which is depicted on the City of Attleboro Tax Assessor's Map No. 49 , as Lot No. 157B [10; 12; 18, pp. 21 - 22; 28, pp. 33, 77; 69]. One background surface soil sample (P - 18 - SS - 04) was collected from a residential property located southeast of the Walton & Lonsbury Inc. property, which is depicted on the City of Attleboro Tax Assessor's Map No. 49 , as Lot No. 96 [12; 18, p. 18; 28, pp. 30, 79; 69]. Three background surface soil samples (P - 22 - SS - 01A, P - 22 - SS - 01B, and P - 22 - SS - 08) were collected from a residential property located southeast of the Walton & Lonsbury Inc. property, which is depicted on the City of At tleboro Tax Assessor's Map No. 4 9, as Lot No. 126 [12; 18, pp. 19 - 20; 28, pp. 31 - 32, 81; 69]. All background surface soil sample locations are depicted in Figure 4. The 10 background surface soil samples were collected i n the vicinity of the site from the same depth interval ( 0 - to 2 - f eet bgs), during the same time period , and utilizing the same collection and analytical methods as the surface soil/source samples presented as part of the Source No. 6 c haracterization [ 18, pp. 4, 15, 18 - 22, 24 - 25, 27 - 28; 28, pp. 18, 27 - 28, 30 - 33, 36, 61, 71, 76 - 77, 79, 80 - 82; 32 , pp. 12 - 16; 35, pp. 43 - 44, 9 4 , 102 - 103, 117, 133 - 134, 137 - 138, 144 - 146 , 148, 151, 155, 163 ; 50, p. 1; 53, p. 1; 60, p. 1; 61, p. 1 ]. The 10 background surface so il samples collected as part of the EPA SR contained varying compositions of naturally occurring native materials ( i.e. , sand, silt, clay, gravel, and organic matter) [ 35, pp. 43 - 44, 9 4 , 102 - 103, 117, 137 - 138, 145, 163 ]. Background surface soil sample SO - 0 1B was described as moist, yellow brown, silt, some fine sand, little clay, trace medium - to - coarse gravel, trace organics, trace medium - to - coarse sand [35, p. 163]. Background surface soil sample P - 06 - SS - 07 was described as brown - to - dark brown, fine - to - coarse sand, some silt, little fine - to - medium gravel, trace organics , trace clay [35, p. 43] . Background surface soil sample P - 06 - SS - 08 was described as brown, silt and fine - to coarse sand, little fine - to - medium gravel, trace organics, trace clay [ 35, p. 44] . Background surface soil sample P - 14 - SS - 01 was described as dry, brown, silt , trace clay, trace fine - to - coarse sand, trace fine - to medium gravel, trace organics [35, p. 9 4 ] . Background surface soil sample P - 16 - SS - 03 was described as moist, brown - to - dark brown, clay, some silt, trace organics, trace fine gravel, trace fine - to - coarse sand [35, p. 102] . Background surface soil sample P - 16 - SS - 04 was described as wet, brown - to - dark brown, clay and silt, trace organics, trace fine - to - coarse sand [35, p . 103] . Background surface soil sample P - 18 - SS - 04 was described as brown, fine - to - coarse sand, little silt, little clay, trace fine - to - medium gravel, trace organics [35, p. 117] . Background surface soil sample P - 22 - SS - 01A was described as dark brown, silt, little organics, trace fine - to - coarse sand [35, p. 137] . Background surface soil sample P - 22 - SS - 01B was described as moist, dark brown, clay and silt, little fine - to - coarse sand, trace organics [35, p. 138] . Background surface soil sample P - 22 - SS - 08 was described as brown, fine - to - coarse sand, some silt, trace fine - to - medium gravel, trace clay, trace organics [35, p. 145] . As presented above, the 10 background surface soil samples contained varying compositions of naturally occurring native matrix materials ( i.e. , sand, silt, cl ay, gravel, and organic matter), which constituted major and/or minor components of the sample s [ 35, pp. 43 - 44, 9 4 , 102 - 103, 117, 137 - 138, 145, 163 ]. Similarly, the source samples presented as part of the Source No. 6 charact erization exhibited varying compositions of the same naturally occurring native matrix materials (see Source Samples presented below). Among the 10 background surface soil samples, various samples contained native matrix material compositions that were sim ilar to those of various surface soil/source samples presented as part of the Source No. 6 Characterization [ 35, pp. 43 - 44, 9 4 , 102 - 103, 117, 133 - 134, 137 - 138, 144 - 146 , 148, 151, 155, 163 ]. The analytical results of each Source No. 6 surface soil/source sa mple could be compared to the contaminant concentrations detected only in those background surface soil sample(s) which displayed the most similar matrix composition. However, for simplicity of th e HRS documentation record , and toSource Characterization Source No. 6

Walton & Lonsbury Inc. 88 HRS Documentation Record MAD001197755 5 September 2012 support the case that ana lytical results of Source No. 6 surface soil/source samples are significantly above documented background concentrations, all 10 background surface soil samples are presented, and Source No. 6 surface soil/source samples were compared to the highest concen trations detected among all 10 background surface soil samples for the analytes presented. Regardless of the approach to comparison of contaminant concentrations [ i.e. , comparing Source No. 6 samples to only the background surface soil sample(s) that were most similar in composition, or comparing surface soil/source samples to the highest concentrations detected among all background surface soil samples] , surface soil/source sample analytical results for Source No. 6 indicate source cont aminant concentrations significantly above background levels. Background surface soil samples SO - 01B, P - 06 - SS - 07, P - 06 - SS - 08, P - 14 - SS - 01, P - 16 - SS - 03, P - 16 - SS 04, P - 18 - SS - 04, P - 22 - SS - 01A, P - 22 - SS - 01B, and P - 22 - SS - 08 were submitted to a CLP l aboratory for c hromium and lead analysis under CLP SOW ISM01.3 [ 18, pp. 27 - 28; 32, pp. 9, 12, 14 - 15; 50, pp. 1, 9; 60, pp. 1, 7; 61, pp. 1, 8 - 9 ]. COCs for all samples collected as part of the 2012 EPA SR and presented in this HRS d ocumentation r ecord are provided in Reference 32. The applicable COC pages for the background surface soil samples, and all corresponding sample identifiers, are provided in available COC and field notes reference documentation [18, pp. 4, 11 - 12, 15, 18 - 22, 25; 32, pp. 9, 12, 14 - 15]. In addition, all sample IDs and associated sample numbers and COC numbers are provided in a reference table [115]. The analytical data were validated on a Tier II level according to EPA Region I Tiered Organic and Inorganic Data Validation G uideline s [ 50, pp. 1, 3; 60, pp. 1, 3; 61, pp. 1, 3 ] . I n addition, the validation was conducted independently by designated chemists who were not involved in the sample collection and HRS evaluation [ 35, pp. 43 - 44, 94, 102 - 103, 117, 137 - 138, 145, 163; 50, pp. 1, 3; 60, pp. 1, 3; 61, pp. 1, 3 ]. As part of this HRS documentation record a nd the evaluation of background concentrations, the following hazardous substances in background surface soil samples are presented: chromium and lead . A mong the 10 background surface soil samples , chromium was detected at a maximum concentration of 14.1 mg/Kg in sample P - 14 - SS - 01; and lead was detected at a maximum concentration of 76.4 mg/Kg in sample P - 22 - SS - 01A [ 18, pp. 4, 11 - 12, 15, 18 - 22, 25, 27 - 28; 28, pp. 61, 71, 76, 77, 79, 81; 50, p. 9; 60, p. 7; 61, pp. 8, 9; 72, pp. 2 3 - 28 , 30 - 31, 72, 74, 81, 82 , 84] . Table 34 - Hazardous Substances Associated with Background Samples Sample ID Sample Type Date Hazardous Substance Hazardous Substance Concentration Sample Adjusted

CRQL Reference SO - 01B Surface Soil 25 Jan. 2012 Chromium 10.7 mg/Kg 0.87 mg/Kg 18, pp. 4, 11 - 12 ; 28, p. 61 ; 50, p. 9 ; 72, pp. 1, 32, 72 Lead 10.1 mg/Kg 0.87 mg/Kg P - 06 - SS - 07 Surface Soil 31 Jan. 2012 Chromium 12.5 mg/Kg 0.98 mg/Kg 18, pp. 15, 27 - 28; 28, p. 71 ; 60, p. 7 ; 72, pp. 1, 2 3 , 74 Lead 23.4 mg/Kg 0.98 mg/Kg P - 06 - SS - 08 Surface Soil 31 Jan. 2012 Chromium 10.3 mg/Kg 1.05 mg/Kg 18, pp. 15, 27 - 28; 28, p. 71 ; 60, p. 7 ; 72, pp. 1, 24, 74 Lead 31.4 mg/Kg 1.05 mg/Kg P - 14 - SS - 01 Surface Soil 1 Feb. 2012 Chromium 14.1 mg/Kg 1.41 mg/Kg 18, pp. 21, 27 - 28; 28, p. 76 ; 61, p. 8 ; 72, pp. 1, 25, 81 Lead 30.4 mg/Kg 1.41 mg/KgSource Characterization Source No. 6

Walton & Lonsbury Inc. 89 HRS Documentation Record MAD001197755 5 September 2012 Table 34 - Hazardous Substances Associated with Background Samples Sample ID Sample Type Date Hazardous Substance Hazardous Substance Concentration Sample Adjusted

CRQL Reference P - 16 - SS - 03 Surface Soil 1 Feb. 2012 Chromium 12.0 mg/Kg 1.60 mg/Kg 18, pp. 21, 27 - 28; 28, p. 77 ; 61, p. 9 ; 72, pp. 1, 26, 81 Lead 59.9 mg/Kg 1.60 mg/Kg P - 16 - SS - 04 Surface Soil 1 Feb. 2012 Chromium 13.3 mg/Kg 1.34 mg/Kg 18, pp. 22, 27 - 28; 28, p. 77 ; 61, p. 9 ; 72, pp. 1, 27, 81 Lead 66.8 mg/Kg 1.34 mg/Kg P - 18 - SS - 04 Surface Soil 1 Feb. 2012 Chromium 11.0 mg/Kg 1.12 mg/Kg 18, pp. 18, 27 - 28; 28, p. 79 ; 61, p. 9 ; 72, pp. 1, 28, 81 Lead 29.4 mg/Kg 1.12 mg/Kg P - 22 - SS - 01A Surface Soil 1 Feb. 2012 Chromium 10.4 mg/Kg 1.67 mg/Kg 18, pp. 19, 27 - 28; 28, p. 81 ; 61, p. 9 ; 72, pp. 1, 81 , 84 Lead 76.4 mg/Kg 1.67 mg/Kg P - 22 - SS - 01B Surface Soil 1 Feb. 2012 Chromium 9.7 mg/Kg 1.44 mg/Kg 18, pp. 19, 27 - 28; 28, p. 81 ; 61, p. 9 ; 72, pp. 1, 30, 82 Lead 38.9 mg/Kg 1.44 mg/Kg P - 22 - SS - 08 Surface Soil 1 Feb. 2012 Chromium 10.0 mg/Kg 1.15 mg/Kg 18, pp. 20, 27 - 28; 28, p. 81 ; 61, p. 9 ; 72, pp. 1, 31, 82 ; 61, p. 9 Lead 51.5 mg/Kg 1.15 mg/Kg Jan. = January CRQL = Contract Required Quantitation Limit Feb. = February mg/Kg = Milligrams per K ilogram

- Source Samples: On 1 and 2 February 2012, as part of the EPA SR and in accordance with the EPA - approved January 2012 Site - Specific QAPP , surface soil/source sampling activities for Source No. 6 were conducted [ 18, pp. 20 - 21, 24, 27 - 28 ; 28, pp. 32 - 33, 36, 80 - 82 ; 31, pp. 1, 26, 32, 40 - 43 ]. As part of the Source No. 6 characterization, seven surface soil/source samples (P - 21 - SS - 03, P - 21 - SS - 04, P - 22 - SS - 07, P - 22 - SS - 09A, P - 22 - SS - 10A, P - 23 - SS - 02, and P - 23 - SS - 06) were collected from residential properties located southeast of the Walton & Lonsbury Inc. property [18, pp. 20 - 21, 24, 27 - 28; 28, pp. 32 - 33, 36, 80 - 82]. Surface s oil/source samples utilized to characterize Source No. 6 include the following: two surface soil/source samples (P - 21 - SS - 03 and P - 21 - SS - 04) collected fro m a property designated as “P 21 ”, depicted on the City of Attleboro Tax Assessor's M ap No. 49, as Lot No. 125 ; three surface soil/source samples (P - 22 - SS - 07, P - 22 - SS - 09A, and P - 22 - SS - 10A) collected fro m a property designated as “P - 22 ”, depicted on the City of Attleboro Tax Assessor's M ap No. 49, as Lot No. 126 ; and two surface soil/source samples (P - 23 - SS - 02 and P - 23 - SS - 06) collected fro m a property designated as “P - 23 ”, depicted on the City of Attleboro Tax Assessor's M ap No. 49, as Lot No. 124 [28, pp. 80 - 82, 69]. All property designations ( e.g. , “P - 01”, “P - 02”, etc. ) were assigned during the 2012 EPA SR , and are associated with the corresponding identifiers for soil samples collected from each property ( e.g. , P - 01 - SS - ##, P - 02 - SS - ##, etc. ) [18, pp. 13 - 14]. All surface soil/source samples collected from Source No. 6 as part of the EPA SR we re collected from depths less than 2 feet bgs [ 35, pp. 133 - 134, 144, 146, 148, 151, 155 ]. Locations of surface soil/source samples collected from Source No. 6 are depicted in Figure 10.Source Characterization Source No. 6

Walton & Lonsbury Inc. 90 HRS Documentation Record MAD001197755 5 September 2012 Surface soil/source samples collected from Source No. 6 were of similar composition to the native materials described in the background surface soil samples presented for Source No. 6. Surface soil/source sample P - 21 - SS - 03 was described as moist, brown, cl ay and silt, little fine - to - coarse sand, trace organics, trace fine gravel [35, p. 133] . Surface soil/source sample P - 21 - SS - 04 was described as moist, dark brown, clay, some silt, little fine sand, trace medium - to - coarse sand, trace fine gravel, trace orga nics [35, p. 134] . Surface soil/source sample P - 22 - SS - 07 was described as wet, dark brown, silt and clay, little fine - to - coarse sand, little organics [35, p. 144] . Surface soil/source sample P - 22 - SS - 09A was described as saturated, dark brown, silt, little clay, trace fine - to - coarse sand, trace organics, trace fine gravel [35, p. 146] . Surface soil/source sample P - 22 - SS - 10A was described as saturated, dark brown, clay and silt, trace fine - to - coarse sand, trace organics [35, p. 148] . Surface soil/source sampl e P - 23 - SS - 02 was described as wet, dark brown, clay and silt, little fine - to - coarse sand, trace fine gravel, trace organics [35, p. 151] . Surface soil/source sample P - 23 - SS - 06 was described as brown - to - dark brown, silt, some fine - to coarse sand, trace orga nics, trace fine gravel, trace clay [35, p. 155] . The seven surface soil/source samples (P - 21 - SS - 03, P - 21 - SS - 04, P - 22 - SS - 07, P - 22 - SS - 09A, P - 22 - SS 10A, P - 23 - SS - 02, and P - 23 - SS - 06) were sub mitted to a CLP l aboratory for chromium and lead analysis under CLP SOW ISM01.3 [ 18, pp. 27 - 28 ; 32, pp. 12 - 13, 16; 53, pp. 1, 10; 60, pp. 1, 8 - 9, 61, pp. 1, 7; ]. COCs for all samples collected as part of the 2012 EPA SR and presented in this HRS d ocumentation r ecord are provided in Reference 32. T he applicable COC pages for the Source No. 6 soil/source samples, and all corresponding sample identifiers, are provided in available COC and field notes reference documentation [18, pp. 20 - 21, 24; 32, pp. 12 - 13, 16]. In addition, all sample IDs and associ ated sample numbers and COC numbers are provided in a reference table [115]. The analytical data for Source No. 6 surface soil/source samples were validated on a Tier II level according to EPA Region I Tiered Organic and Inorganic Data Validation Guideline s [ 53, pp. 1, 4; 60, pp. 1, 3, 61, pp. 1, 3 ]. I n addition, the validation was conducted independently by designated chemists who were not involved in the sample collection and HRS evaluation [ 35, pp. 133, 134, 144, 146, 148, 151, 155; 53, pp. 1, 4; 60, pp. 1, 3, 61, pp. 1, 3 ]. Among the seven surface soil/source samples, chromium was detected at a maximum concentration of 1,180 mg/Kg in surface soil/source sample P - 23 - SS - 02 , and lead was detected at a maximum concentration of 554 mg/Kg in surface soil/sou rce sample P - 22 - SS - 10A [ 18, pp. 20 - 21, 24, 27 - 28; 28, pp. 80 - 82; 53, p. 10; 60, pp. 8, 9; 61, p. 7; 72, pp. 55 - 61, 75, 79, 80 ]. Based on chemical analysis of surface soil/source samples collected during the EPA SR , Source No. 6 has been documented to contain chromium and lead , which are defined as hazardous substances according to the HRS Rule [1, p. 51586; 7, pp. 7, 14 - 15; 8, pp. 52 - 56; 28, pp. 80 - 82; 53, p. 10; 60, pp. 8, 9; 61, p. 7; 72, pp. 55 - 61, 75, 79, 80 ]. The hazardous substances chromium and lead were detected in Source No. 6 surface soil/source samples at concentrations significantly above background concentrations [28, pp. 80 - 82; 53, p. 10; 60, pp. 8, 9; 61, p. 7; 72, pp. 55 - 61, 75, 79, 80]. Therefore, chromium and lead are considered to be associated with Source No. 6 [1, p. 51588, Section 2.2.2]. Only contaminated surface soil /source samples which contain hazardous substance concentrations greater than or equal to three times background levels are present ed for the Source No. 6 character ization. Per the HRS, contaminated surface soil/source samples with hazardous substance concentrations above background levels, but less than three times background levels, could be presented as part of the source characterization. However, for the simplic ity of this HRS documentation record, and to identify a significant increase in source hazardous substance concentrations compared to background levels , only the contaminated surface soil /source samples with hazardous substance concentrations greater than or equal to three times background levels are presented . If all contaminated surface soil/source samples with hazardous substance concentrations above background levels were included in the sourceSource Characterization Source No. 6

Walton & Lonsbury Inc. 91 HRS Documentation Record MAD001197755 5 September 2012 characterization, the extent of contamination for Source No . 6 would be larger than the area delineated by the selection of surface soil/ source samples that are presented. Table 35 - Hazardous Substances Associated with Source No. 6 Sample ID Sample Type Date Hazardous Substance Hazardous Substance Concentration Sample Adjusted

CRQL Reference P - 21 - SS - 03 Surface Soil /Source 1 Feb. 2012 Chromium 327 mg/Kg 1.35 mg/Kg 18, pp. 20, 27 - 28; 28, p. 80 ; 60, p. 8 ; 72, pp. 1, 55, 75 Lead 300 mg/Kg 1.35 mg/Kg P - 21 - SS - 04 Surface Soil/Source 1 Feb. 2012 Chromium 799 mg/Kg 1.37 mg/Kg 18, pp. 20, 27 - 28; 28, p. 80 ; 60, p. 8 ; 72, pp. 1, 56, 75 Lead 236 mg/Kg 1.37 mg/Kg P - 22 - SS - 07 Surface Soil/Source 1 Feb. 2012 Chromium 271 mg/Kg 2.19 mg/Kg 18, pp. 20, 27 - 28; 28, p. 81 ; 61, p. 7 ; 72, pp. 1, 57, 80 Lead 267 mg/Kg 2.19 mg/Kg P - 22 - SS 09A Surface Soil/Source 2 Feb. 2012 Chromium 135 mg/Kg 1.45 mg/Kg 18, pp. 24, 27 - 28; 28, p. 82 ; 53, p. 10 ; 72, pp. 1, 58, 79 P - 22 - SS 10A Surface Soil/Source 2 Feb. 2012 Chromium 153 mg/Kg 1.63 mg/Kg 18, pp. 24, 27 - 28; 28, p. 82 ; 53, p. 10 ; 72, pp. 1, 59, 79 Lead 554 mg/Kg 1.63 mg/Kg P - 23 - SS - 02 Surface Soil/Source 1 Feb. 2012 Chromium 1,180 mg/Kg 1.14 mg/Kg 18, pp. 21, 27 - 28; 28, p. 82 ; 60, p. 9 ; 72, pp. 1, 60, 75 Lead 330 mg/Kg 1.14 mg/Kg P - 23 - SS - 06 Surface Soil/Source 1 Feb. 2012 Chromium 833 mg/Kg 0.97 mg/Kg 18, pp. 21, 27 - 28; 28, p. 82 ; 60, p. 9 ; 72, pp. 1, 61, 75 Lead 232 mg/Kg 0.97 mg/Kg Feb. = February CRQL = Contract Required Quantitation Limit. mg/Kg = Milligrams per K ilogram List of Hazardous Substances Associated with Source Chromium Lead 2.2.3 HAZARDOUS SUBSTANCES AVAILABLE TO A PATHWAY The area of Source No. 6 (4,350.89 ft 2 ) includes the surface soil/source sampl e locations which document contamination with chromium and lead, and the area s lying between these locations; with the exception of the areas which ar e covered with permanent water cover or wetlands [ 28, pp. 80 - 82; 53, p. 10; 60, p p. 8, 9; 61, p. 7; 7 1 , pp. 1, 3 - 4, 8 ; 72 , pp. 55 - 61, 75, 79, 80 ]. The total area between contaminated surface soil/source samples , including area s of permanent water cover or wetlands , was determined to be 10,536.43 ft 2 [71 , pp. 1, 3 - 4 ]. Based on on - site observations, wetland deli neation activities, and interpretation of aerial imagery using GIS software , t he area covered with permanent water cover or wetlands was determined to be 6,185.54 ft 2 [ 71 , pp. 1, 3 - 4 ]. Therefore, based on analysis of GPSSource Characterization Source No. 6

Walton & Lonsbury Inc. 92 HRS Documentation Record MAD001197755 5 September 2012 coordinates recorded for the locations of the seven surface soil/source sample s presented above, analysis and examination of aerial photographs of the area, and on - site observations, the area of Source No. 6 not covered by water cover and wetlands is 4,350.89 ft 2 ( 10,536.43 ft 2

- 6,185.54 ft 2 = 4,350.89 ft 2 ) [ 71 , pp. 1, 3 - 4 ]. On - site observations indicate that no portion of Source No. 6 has a maintained engineered cover or complete run - on or runoff control management systems [ 18 , p. 28 ]. Th erefore, Source No. 6 does not have full containment, and the source yields a containment v alue of 10 for the overland flow component of the Surface Water pathway [1, p. 51609 (Table 4 - 2)]. Table 3 6 - Hazardous Substances Available to Pathways Containment Description Containment Factor References Release via overland migration and/or flood : Based on the lack of a maintained engineered cover, and any complete run on and runoff control management systems, a Containment Factor Value of 10 has been assigned for release via overland migration and/or flood for Source No. 6 . 10 1, p. 51609 (Table 4 - 2) ; 18 , p. 28; 71 , pp. 1, 3 - 4 2.4.2 HAZARDOUS WASTE QUANTITY 2.4.2.1 Hazardous Waste Quantity The Hazardous Waste Quantity for Source No. 6 was assigned based on the Area Assigned Value of a “contaminated soil” source type [1, p. 51591 (Table 2 - 5, Section 2.4.2.1. 4 )]. The Hazardous Constituent Quantity, Hazardous Wastestream Quantity, and Volume Assigned Values wer e not evaluated for Source No. 6 because insufficient infor mation was available , as described in the sections below [1, p. 51591 (Table 2 - 5, Sections 2.4.2.1.1 , 2.4.2.1.2 and 2.4.2.1.3 )]. 2.4.2.1.1 Hazardous Constituent Quantity Description The H azardous C onst ituent Q uantity for Source No. 6 could not be adequately determined according to the HRS Rule requirements; that is, the total mass of all CERCLA hazardous substances in the source and releases from the source is not known and cannot be estimated with reasonable confidence [1, pp. 51590 - 51591 (Section 2.4.2.1.1)]. Insufficient historical and current data ( m anifests, PRP records, State records, p ermits, w aste concentration data, etc.) are available to adequately calculate the total mass of all CERCLA hazardous substances in the sourc e and the associated releases from the source. Therefore, there is insufficient information to evaluate the associated releases from the source to calculate the H azardous C onstituent Q uantity for Source No. 6 with reasonable confidence. Table 37 – Hazardo us Constituent Quantity Hazardous Substance Constituent Quantity (pounds) References NS (insufficient information) Sum (pounds):Source Characterization Source No. 6

Walton & Lonsbury Inc. 93 HRS Documentation Record MAD001197755 5 September 2012 Hazardous Constituent Quantity Assigned Value: NS 2.4.2.1.2 Hazardous Wastestream Quantity Description The H azardous W astestream Q uantity for Source No. 6 could not be adequately determined according to the HRS Rule requirements; that is, the total mass of all hazardous wastestreams and CERCLA pollutants and contaminants for the source and releases from the source is not known and cannot be estimated with reasonable confidence [1, p. 51591 (Section 2.4.2.1.2)]. Insufficient historical and current data (manifests, PRP records, State records, permits, waste concentration data, annual reports, etc.) are available to adequate ly calculate the total mass of all hazardous wastestreams and CERCLA pollutants and contaminants for the source and the associated releases from the source. Therefore, there is insufficient information to adequately calculate or extrapolate the H azardous W astestream Q uantity for Source No. 6 with reasonable confidence. Tabl e 38 – Hazardous Wastestream Quantity Hazardous Wastestream Wastestream Quantity (pounds) References NS (insufficient information) Sum (pounds): Sum of Wastestream Quantity/5,000 (1, p. 51591, Table 2 - 5): Hazardous Wastestream Quantity Assigned Value : NS 2.4.2.1.3 Volume Description The volume for Source No. 6 could not be adequately determined according to the HRS Rule requirements due to insufficient historical and current waste sampling data available to adequately calculate the volume of the source with reasonable confidence [1, p. 51591 (Section 2.4.2.1.3)]. Insufficient historical or current sampling data are available to adequately estimate the depth of waste material w ithin the source. Therefore, there is insufficient information to adequately calculate or estimate the volume for Source No. 6 with reasonable confidence. Table 39 – Volume Source Type Description (# drums or dimensions) Units (yd 3 ) References NS (insufficient information) Sum (yd 3 ): Equation for Assigning Value (1, p. 51591, Table 2 - 5):Source Characterization Source No. 6

Walton & Lonsbury Inc. 94 HRS Documentation Record MAD001197755 5 September 2012 Volume Assigned Value: NS 2.4.2.1.4 Area Description The area of Source No. 6 includes the surface soil/source sampling locations which document contamination with chromium and lead, and the area s lying between these locations, with the exception of the areas which are covered with permanent water cover or wetlands [ 28, pp. 80 - 82; 53, p. 10; 60, p p. 8, 9; 61, p. 7; 71 , pp. 1, 3 - 4 , 8 ; 72 , pp. 55 - 61, 75, 79, 80 ]. The area of Source No. 6 was determined by connecting five contaminated surface soil/source sample GPS locations [ P - 23 - SS - 06, P - 23 - SS - 02, P - 22 - SS - 09A, P - 22 - SS - 10A, and P - 22 - SS - 07 ] with straight lines , using GIS software [71, pp. 1, 3 - 4 ]. The total area between contaminated surface soil/source samples locations , including area s of permanent water cover or wetlands, was determined to be 10,536.43 ft 2 [ 71 , pp. 1, 3 - 4 ]. B ased on on - site observations, the results of wetland delineation activi ties, and an interpretation of aerial imagery using GIS software , t he area covered with permanent water cover was determined to be 6,185.54 ft 2 [ 71 , pp. 1, 3 - 4 ]. Source No. 6 therefore comprises 4,350.89 ft 2 of contaminated soil ( 10,536.43 ft 2

- 6,185.54 ft 2 = 4,350.89 ft 2 ) . Table 40 – Area Source Type Units (ft 2 ) References Contaminated Soil 4,350.89 71 , pp. 1, 3 - 4 ft 2 = Square Feet . The area of a “contaminated soil” source, in ft 2 , is divided by 34,000 to assign a Hazardous Waste Quantity to the source [1, p. 51591, Table 2 - 5]. Sum (ft 2 ): 4,350.89 Equation for Assigning Value (1, p. 51591, Table 2 - 5): 4,350.89 ft 2 ÷ 34,000 = 0. 13 Area Assigned Value: 0.13 2.4.2.1.5 Source Hazardous Waste Quantity Value The Hazardous Waste Quantity Value for Source No. 6 was assigned bas ed on the Area Assigned Value (0. 13) [1, p. 51591, Table 2 - 5]. The Hazardous Constituent Quantity, Hazardous Wastestream Quantity, and Volume Assign ed Values wer e not evaluated for Source No. 6 because insufficient information was available [1, p. 51591, Sections 2.4.2.1.1, 2.4.2.1.2, 2.4.2.1.3]. Highest HWQ value assigned from Ref. 1, Table 2 - 5: 0.13Source Characterization Summary

Walton & Lonsbury Inc. 95 HRS Documentation Record MAD001197755 5 September 2012 SUMMARY OF SOURCE DESCRIPTIONS Table 4 1 – Summary of Source Descriptions

Source

No. Source HWQ Value Source Hazardous Constituent

Quantity Complete? (Y/N) Containment Factor Value by Pathway Ground Water (GW) (Ref. 1, Table 3 - 2) Surface Water (SW)* Air Overland/ flood (Ref. 1, Table 4 - 2) GW to SW (Ref. 1, Table 3 - 2) Gas (Ref. 1, Table 6 - 3) Particulate (Ref. 1, Table 6 - 9) 1 469.2 N NS 10 NS NS NS 2 760 N NS 10 NS NS NS 3 10,0 29.9 N NS 10 NS NS NS 4 0.36 N NS 10 NS NS NS 5 0.36 N NS 10 NS NS NS 6 0.13 N NS 10 NS NS NS HWQ = Hazardous Waste Quantity. NS = Not Scored. No. = Number. Total Source Hazardous Waste Quantity Value: 11, 2 59.95 Other possible sources not scored: Two source areas , a former Dry Well and the Chrome Plating Tank Exhaust Dusts/Electrical Room Roof Area, have been documented . These sources were not scored due to the lack of information to sufficiently characterize the sources. Dry Well According to the 1989 RCA Pha se I Limited SI report, a n abandoned dry well was located on the south side of the Walton & Lonsbury Inc. facility building [24, pp. 18 - 19 ]. Reportedly, the dry well was used for disposal of waste TCE, and has been considered to be a potential source area for various organic pollutants [24, pp. 18 - 19 ]. According to a 1990 RCA Phase IIA Preliminary Comprehensive Site Assessment report, during various interviews with a former Walton & Lonsbury Inc. employee, an abandoned dry well was identified in the courtya rd area, south of the chromium plating room [17, pp. 49, 57 ]. This employee reported that many years ago, the dry well was used for disposal of TCE [17, p. 49, 57 ]. To further investigate this dry well, RCA conducted ground penetrating radar (GPR) survey work in the area, and installed monitoring well MW - 8 downgradient of the suspected location of the dry well. There was a slight depression in the ground’s surface at the suspected location of the dry well; however, RCA concluded that neither the GPR nor the ground water analytical results from MW - 8 supported a discharge of TCE into the dry well [17, p. 57 ]. However, according to a 2005 Site Inspection report prepared by Tetra Tech NUS, Inc., analytical results of ground water samples collected from monitoringSource Characterization Summary

Walton & Lonsbury Inc. 96 HRS Documentation Record MAD001197755 5 September 2012 micro - wells during the 1989 RCA Phase I SI confirmed the presence of VO Cs in ground water downgradient of the drywell [25, p. 13]. The dry well could not be located during either the 1989 or 1 990 RCA investigations [17, p . 4 9; 24, p. 19 ]. In addition, both the 1989 and 1990 RCA reports have discrepancies on whether the dry well was located on the south side or east side of the building [ 17, p. 57; 24, p p . 18, 53 ]. This source was not scored as part of this HRS documentat ion record, as the source location and the nature and extent of hazardous substances potentially associated with this source require further investigation, and its inclusion into this HRS evaluation would not impact the overall site score. Chrome Plating Tank Exhaust Dusts/Electrical Room Roof Area According to the 1989 RCA Phase I Limited SI report and the 1990 RCA Phase IIA Preliminary Comprehensive Site Assessment report, the Walton & Lonsbury Inc. facility electrical room roof was loca ted immediately below the exhaust ducts from the chromium plating tanks [17, pp. 8, 50 ; 24, pp. 11 , 19 , 49 ]. During the years that Walton & Lonsbury Inc. operated the plating facility , chromium residue accumulated on the electrical room roof of the building [17, pp. 8, 50, 55 ; 24, pp. 11 , 19 , 49 ]. During storm events, runoff from the roof picked up dissolved chromium and was subsequently discharged to the ground [17, pp. 8, 50, 55 ; 24, pp. 11 , 19 , 49 ]. Analytical results of s amples of the r o of runoff collected by RCA from the area of the electrical room roof indicate d elevated c hromium concentrations and redu ced pH levels [17, p. 55 - 56 ; 25, p. 13]. This source was not scored, as the building has been demolished , and the nature and extent of hazardous substances potentially associated with this source require further investigation; furthermore, the inclusion of this source into th e HRS evaluation would not impact the overall site score.Surface Water Overland Flow General

Walton & Lonsbury Inc. 97 HRS Documentation Record MAD001197755 5 September 2012 4.0 SURFACE WATER MIGRATION PATHWAY 4.1 OVERLAND/FLOOD MIGRATION COMPONENT 4.1.1 GENERAL CONSIDERATIONS C hromium electroplating operations were conducted on the Walton & Lonsbury Inc. property between 1940 and 2007 [15 , p. 2 ; 23 , pp. 5 - 6 ]. Various reference docume ntation available from between 1983 and 2007 , including Annual Reports, Hazardous Waste Reports, Hazardous Waste Manifest records , and documentation prepared by RCA for Walton & Lonsbury Inc., have identified the use, generation , and /or disposal of contaminated wastes such as the following: “chrome sludge”’; “chromic acid”; “chrome plating rinse water”; “corrosive chromic - acid - contaminated solid debris, from chrome - plating operation”; “ chromic acid in water ” ; and “chromic - acid contaminat ed steel ductwork ventilation system for chrome plating operation” [ 24 , pp. 16 - 17 , 77 ; 80, pp. 26 - 28 ; 81, pp. 1, 7; 85, pp. 1 - 2, 10; 86, pp. 1, 3 - 4, 7; 84]. Lead has also been identified as having been used in former operational processes on t he property [ 15, pp. 2 - 3]. The Walton & Lonsbury Inc. facility building contained a lead smelter and exhaust hood associated with the manufacture of plumbing components involved in the plating process [15, p. 3]. Through chemical analysis of source samples collected d uring the 2012 EPA SR, the hazardous substances chromium and lead have been documented to be associated with six sources , which each have a Containment Factor value of 10 for release via overland migration and/or flood (see the Source Characterization sect ion above). These sources include two pile sources (Source Nos. 1 and 2); one surface impoundment source (Source No. 3); and three contaminated soil sou rces (Source Nos. 4, 5, and 6) . The Walton & Lonsbury Inc. property is located within the Narragansett Watershed [ 108, p. 1 ]. Hazardous substances from associated sources release along two separate in - water segments, which form two separate branches of the hazardous substance migration path prior to the two branches joining together within the TDL for the site [19, pp. 1 - 2, 6; 24, p. 46 ; 28, p. 10; 103, p. 2] . One branch of the hazardous substance migration path for the site consists of overland su rface water flow to the south of the Walton & Lonsbury Inc. property , to an area of open water at PPE No. 2 , and subsequently to a wetland area south of the property [19, p. 2] . A second branch of surface water flow originates via contaminant infiltration to the ground water , which flows beneath the Walton & Lonsbury Inc. property to the east southeast and emerge s as surface water discharge at residential properties along the eastern portion of Paulette Lane [23, p. 47; 25, p. 32; 103, p. 2] . The most upstream ground water discharge to s urface water is located along the wetlands associated with the Bliss Brook hea dwaters (PPE No. 1) [19, pp. 1, 6] . The two branches of in - water segments for the hazardous substance migration path converge within Bliss Brook, immediately south of the West Street bridge (south of the Walton & Lonsbury Inc. property) [19, pp. 1 - 2; 103, p. 2 ]. Based on topography and previous reports, stormwater runoff/overland flow from the Walton & Lonsbury Inc. property flows in a southeasterly direction, toward the wetland located south of the property [ 11, p. 2 ; 23, pp. 46 - 47; 24, p. 11 ; 25, p. 32 ]. A 1989 report prepared by RCA, for Walton & Lonsbury Inc., indicated that terrain in the area of the Walton & Lonsbury Inc. property is relatively flat, with a gradual slope toward the southeast [24, p. 11 ]. The RCA report further stated that at the time of the report, all runoff from the paved parking lot and the Walton & Lonsbury Inc. building roof flowed off the property in a southeasterly direction, into low - lying areas and wetlands [24, p. 11 ]. Previous reports prepared by RCA, on behalf of Walto n & Lonsbury Inc., identified surface water run - off as a potential source of chromium contamination to the wetland south of the Walton & Lonsbury Inc. property [17, p. 8 - 9, 11 ; 23, p. 47; 24, pp. 13 , 19 ]. A 1989 RCA report states that a potential historica l source of chromium contamination to portions of the wetland was surface water run - off of chromium - contamina ted residueSurface Water Overland Flow General

Walton & Lonsbury Inc. 98 HRS Documentation Record MAD001197755 5 September 2012 from the electrical room roof of the building , due to the roof’s proximity to exhaust ducts from the facility’s chromium plating tanks [24 , pp. 11 , 19 , 49 - 50 ]. Based on on - site observations made during 2012 EPA SR sampling activities, surface water runoff currently flows off the Walton & Lonsbury Inc. property in a southeasterly direction toward a low - lying area of open water at PPE No. 2 , prior to discharging to the wetland south of the property [18, p. 29 ; 103, p. 4 ]. The area of open water was created as a result of excavation activities conducted during the EPA EPRB Removal Action [103, p. 4]. Two pile sources located on the Walton & Lonsbury Inc. property have been evaluated and documented to contain chromium and lead (see Source Nos. 1 and 2 Characterization). On - site observations indicate that no portions of Source Nos. 1 and 2 ha ve a maintained engineered cover or complete run - on or run - off control management systems [ 18 , p. 28 ]. From PPE No. 2 , surface water flows from the area of open water to the wetland area south of the Walton & Lonsbury Inc. property [19, p. 2, 6 ; 28, p. 10; 103, p. 2]. During a 2012 wetland delineation performed by EPA, this wetland area was determined to consist of 8.5 acres of HRS - eligible wetlands, with a total perimeter of 0.811 miles (see Figure 11) [103, pp. 10, 26]. According to a 1989 report prepared by RCA, on b ehalf of Walton & Lonsbury Inc., untreated wastewater from chromium plating operations was historically discharged via a pipe directly into the wetlands located south of the Walton & Lonsbury property [24, pp. 17 - 18 , 59 ; 88]. According to a figure produce d by RCA, on behalf of Walton & Lonsbury Inc., the pipe extended southwest from the “chrome electro plating area” within the facility building [24, p. 59 ; 88]. In the early 1970s, a wastewater treatment system for metals removal and pH adjustment was installed, and the pipe was reportedly “abandoned and plugged” [24, p. 18 ]. D uring excavation activities conducted in April 2011 as part of the EPA EPRB Removal Action, EPA uncovered a pipe extending southwest toward the wetlands from an area identif ied as the “ former chromium plating room ” [16, p. 4; 26, pp. 8 - 9]. XRF field screening results of solid material encountered within the pipe indicated concentrations of chromium at 157,813 mg/Kg, and lead at 78,876 mg/Kg [2 7 ]. According to the results of E PA’s examination of historical aerial photographs, the uncovered pipe terminated at the approximate edge of a former unnamed stream , which historically flowed south from the Walton & Lonsbury Inc. property toward the wetland [16, p. 4]. A Surface Impound ment Source (Source No. 3) , located within the wetlands south of the Walton & Lonsbury Inc. property , has been evaluated and documented to contain chromium and lead (see Source No. 3 Characterization ). Based on analytical sampling results, on - site observat ions, and documentation provided by the City of Attleboro, MA Department of Public Works , Source No. 3 exhibits evidence of hazardous substance migration and a lack of maintained diking [ 18, p p. 25 , 27 - 28 ; 21 ; 28, pp. 37, 65; 32, p. 11; 53, pp. 1, 12]. In addition, a contaminated soil source (Source No. 4), located adjacent to (east of) the wetland area south of the Walton & Lonsbury Inc. property , has been evaluated and documented to contain chromium and lead (see Source No. 4 Characterization). On - site ob servations indicate that no portion of Source No. 4 has a maintained engineered cover or complete run - on or run - off control management systems [ 18 , p. 28 ]. Surface water from the wetlands south of the Walton & Lonsbury Inc. property flows south toward a drainage culvert , located in the southeastern portion of the wetlands near the corner of Deanville Road and North Avenue [19, p. 2 ; 28, p. 10; 103, p. 4 ]. Based on observations and investigations conducted as part of the EPA SR , as well as information pr ovided by City of Attleboro , MA personnel, surface water from the wetlands enter s the drainage culvert and flows south - southeast through piping underneath Deanville Road [18, pp. 13, 16, 25; 21]. Surface water flows through this piping to a manhole on a r esidential property along the southern side of Deanville Road , identified on the City of Attleboro Tax Assessor's Map No. 49, as Lot No. 114B [18, pp. 13, 16, 25; 21]. On 2 February 2012, as part of the EPA SR , one sediment sample (SD - 09) was collected fro m the manhole on this residential property , to document migration of contamination downstream from the wetland [18, p. 25; 28, pp. 37, 65; 69].Surface Water Overland Flow General

Walton & Lonsbury Inc. 99 HRS Documentation Record MAD001197755 5 September 2012 Validated analytical results of SD - 09 indicated a chromium concentration of 672 mg/Kg [18, pp. 27 - 28; 32, p. 1 1; 53, pp. 1, 12 ; 72, pp. 22, 77] . Based on the results of field investigations , water exits th e manhole via a pipe directed east - southeast, flows to a catchbasin located on an adjacent property to the east, and flows farther east to a catchbasin along North Avenue [18, p. 16] . Based on field observations and City of Attleboro diagrams, water then flows south along North Avenue and east along West Street through underground piping, prior to discharging to Bliss Brook immediately south of the West Street bridg e [ 22, p. 2; 103 p. 2 ] . The total distance that surface water flows through underground piping, from the point at which it enters the drainage culvert near the corner of Deanville Road and North Avenue to the point where it discharges to Bliss Brook south of the West Street bridge , is approximately 1,006 feet (0.19 mile) [19 , p. 2; 103 p. 2 ]. Immediately s outh of the West Street bridge, surface water within this branch of the hazardous substance mig ration path converges with the other branch of the hazardous substance migration path, which consist s of an ongoing ground water - to - surface water release southeast of the Walton & Lonsbury Inc. property [19, pp. 1, 2, 6; 103, p. 2 ]. The most upstream ground water discharge to surface water i s located along the wetlands associated with the Bliss Brook headwaters (PPE No. 1) [19, pp. 1, 6]. Surface water then flows south within Bliss Brook ( past West Street) until the point where Bliss Brook converges with the Bungay River (approximately 0.40 miles downstream of PPE No. 1) [19, pp. 1 - 2; 103, p. 2 ]. Surface water subsequently flows southwest along the Bungay River for a short distance (less than 200 feet) , prior to converging with the Ten Mile River just north of the Water Street b ridge [19, pp. 1 - 2; 103, p. 2 ] . Surface water f low within the Ten Mile River continues southwest , and then flows south through Mechanics Pond for a distance of approximately 0.51 miles to the pond’s outlet [103, p. 2]. Surface water then continues to flow in a southerly direction along the Ten Mile River until the terminus of the 15 - mile downstream TDL in the Seekonk River in East Providence, Rhode Island [19, pp. 1 - 2]. Based on the results of the 2012 EPA wetland delineation, numerous segments of HRS - eligible wetlands are located along surface water bodies within the hazardous substance migration path that results from ground water - to - surface water release [103, pp. 4 - 5, 8, 10]. These include HRS - eligible wetlands along Bliss Brook , the Bungay Rive r , and the Ten Mile River , including Mechanics Pond [103, pp. 4 - 5, 8, 10]. In addition, a potential freshwater fishery has been noted along the downstream surface water bodies [ 25, pp. 32 - 33 ; 28, p. 41 ]. Investigations conducted by RCA , on behalf of Walton & Lonsbury Inc., have identified a dissolved chromium ground water plume associated with t he Walton & Lonsbury Inc. property; and have identified ground water - to - surface - water transport as an active mechanism for contaminant transport from the Walton & Lonsbury Inc. property to residential properties along Paulette Lane , and to Bliss Brook and downstream freshwater surface water bodies [23, pp. 44, 47, 69 - 70]. Analytical results of samples collected during previous investigations docum ented elevated concentrations of chromium and hexavalent chromium in pooled surface water and shallow ground water at residential properties along Paulette Lane, as well as associated lead and chromium contamination in soils at residential properties along Paulette Lane (see the Site Summary section for a more detailed discussion) [ 16, pp. 9 - 10; 23 , pp. 37, 95 ; 29, pp. 15, 38 - 39, 52 ] . In addition, n umerous investigations, including the 2001 RCA Phase IIC investigation, the 2005 EPA Site Inspection, the 2011 MassDEP surface water sampling event, and the 2012 EPA SR, have i dentified impacts to surface water and sediments along Bliss Brook associated with ground water - to surface water contaminant release from the W alton & Lonsbury Inc. property (see the Sou rce Identification section of Source No. 5 for a more detailed discussion). Two contaminated soil source s (Source No s . 5 and 6 ), l ocated southeast of the Walton & Lonsbury Inc. property on areas of residential properties adjacent to Bliss Brook, have been evaluated and documented to contain chromium and lead (see Source No s . 5 and 6 Characterization). On - site observations indicate that no portion s of Source No s . 5 and 6 ha ve a maintained engineered cover or complete run - on or run - off control managemen t systems [ 18 , p. 28 ]. The most upstream PPE for Source No. 5 is located in the northern portion of Source No. 5, at the junction of Source No. 5 and wetlands located immediately westSurface Water Overland Flow General

Walton & Lonsbury Inc. 100 HRS Documentation Record MAD001197755 5 September 2012 of Bliss Brook [19, pp. 2 - 3, 6] . The most upstream PPE for Source No. 6 is located in the northern portion of Source No. 6, at the junction of Source No. 6 and wetlands along Bliss Brook [19, pp. 3, 6] . This HRS documentation record only evaluates the release of hazardous substances via overland flow to the wetland located im mediately downgradient (south) of the Walton & Lonsbury Inc. property [19, p. 2 - 3]. This HRS documentation record does not evaluate the remainder of the overland/flood hazardous substance migration path, downstream of this wetland. This HRS documentation record also does not evaluate potential impacts to sensitive environme nts/targets located along Bliss Brook due to a release via ground water - to - surface water flow , nor does it evaluate the remainder of the TDL following the convergence of the two branches of the hazardous substance migration path for the site . 4.1.1.1 Defi nition of Hazardous Substance Migration Path for Overland/Flood Component The PPE for Source Nos. 1 and 2 is the surface water located directly south of the sources. The PPE for Source 3 was the boundary between the source, wetland and surface water surro unding the source. The PPE for Source 4 is the boundary between the contaminated soil and the surface water. PPE No. 2 represents the approximate point at which surface water runoff/overland flow from the Walton & Lonsbury Inc. property and three associat ed sources (Source Nos. 1, 2, and 3) discharge to the area of open water located south of the property [19, pp. 2 - 3, 6] . From this area of open water, surface water flows west and south into the wetland located south of the Walton & Lonsbury Inc. property [19, pp. 2, 6]. The results of the EPA wetland delineation indicated a total area of 8.5 acres of wetlands south of the Walton & Lonsbury Inc. property, with a total perimeter of 0.811 miles (see Figure 11) [103, pp. 10, 26]. In addition, field observations indicated that there was no discernible flow ( e.g. , defined channel) through th is wetland area [103, p. 4] . Source No. 4 is located adjacent to (east of) the wetland area south of the Walton & Lonsbury Inc. property, along the western portio ns of residential properties along North Avenue . The most upstream PPE for Source No. 4 is located at th e junction of the northern portion of Source No. 4 and the eastern edge of the wetland area located south of the Walton & Lonsbury Inc. property [19, pp . 2, 6] . As a result of the 2012 EPA SR, contaminated Source No. 4 s urface soil/source samples were identified ; these Source No. 4 surface soil/source samples were collected from low - lying areas along the western portions of residential properties along North Avenue [18, pp. 15 - 16, 23; 28, pp. 67, 69 - 73, 83 ]. Based on site topography and on - site observations, the area of Source No. 4 is subject to surface water flooding from the wetlands [11; 18, pp. 15 - 16, 23; 19, pp. 2, 6; 109, pp. 1, 4]. From the wetlands south of the Walton & Lonsbury Inc. property, surface water flows south toward a drainage culvert , located in the southeastern portion of the wetlands, into a piped section of the culv ert underneath Deanville Road, and toward a manhole on a residential property along Deanville Road [ 18, pp. 13, 16, 25; 19, p. 2 ; 21; 28, p. 10; 103, p. 4 ]. Analytical results of a sediment sample collected from this manhole have documented migration of a hazardous substance (chromium) from the wetland; howev er, additional targets downstream of the wetland have not been evaluated as part of this HRS documentation record [ 18, p p . 25 , 27 - 28 ; 28, pp. 37, 65; 32, p. 1 1; 53, pp. 1, 12 ; 72, pp. 22, 77 ]. 4.1.1.2 Target Distance Limit The most upstream PPE for overland su rface water flow for the site is located south of the Walton & Lonsbury Inc. property, at an area of open water immediately adjacent to the wetland area south of the property (PPE No. 2) [19, pp. 2, 6]. The most upstream PPE for ground water - to - surface water flow for the site is l ocated southeast of the Walton & Lonsbury Inc. property, along the wetlands associated w ith the Bliss Brook headwaters (PPE No. 1) [19, pp. 1, 6] .Surface Water Overland Flow General

Walton & Lonsbury Inc. 101 HRS Documentation Record MAD001197755 5 September 2012 Based on sampling outlined in Section 4.1.2.1.1 of this evaluation, sediments impacted by hazardous substances attributable to the site ha ve been documented from PPE No. 2 , south through the wetland (sediment samples SD - 04 B , SD - 05 A , SD - 06 A, and SD - 08 B ), to sediment sample SD - 07 A , located in th e wetland immediately upstream (north) of the drainage culvert near the corner of Deanville Road and North Avenue (see Figures 2 and 11 ) [18, pp. 4 - 5, 7, 9 ; 19, p. 2 ; 21; 28, p. 10; 103, p. 2]. Sediment sample SD - 07 is the most downstream sample location documenting an observed release to the wetlands located south of the Walton & Lonsbury Inc. property (see Section 4.1.2.1.1 ). Therefore, as observed contamination is not documented more than 15 m iles downstream of PPE No. 2, the TDL extends 15 miles downstream of the most downstream PPE for the site [1, p. 51605 (Section 4.1.1.2)]. The most downstream PPE for the site is the most downstream PPE for Source No. 6, located southeast of the Walton & Lonsbury Inc. property. The d ownstream PPE for Source No. 6 is located in the southern portion of Source No. 6, at the junction of Source No. 6 and wetlands along Bliss Brook [19, pp. 3, 6] . The total TDL for the site, as measured from 15 miles downstream of the most downstream PPE, is 15.52 miles, and terminates in the Seekonk River in East Providence, Rhode Island [19, pp. 2, 5]. 4.1.2.1 Likelihood of Release 4.1.2.1.1 Observed Release Direct Observat ion Direct observation was not established for the overland flow/flood migration component of the surface water pathway. Basis for Direct Observation: Hazardous Substances in Release: Table 4 2 – Hazardous Substances Documenting an Observed Release to Sediment Hazardous Substance Evidence References NS NS = Not Scored. Chemical Analysis Background Concentrations : On 25 and 26 January 2012, as part of the EPA SR and in accordance with the EPA - approved January 2012 Site - Specific QAPP , background sediment sampling activities were conducted [ 18, pp. 5 - 6 , 9; 28, pp. 19, 23, 63; 31, pp. 1, 26, 30, 36, 38 ]. Two background sediment samples (SD - 01C and SD - 01D) were collected from an upstream tributary on an undeveloped parcel located southwest of the Walton & Lonsbury Inc. property , depicted on the City of Attleboro , MA Tax Assessor ’s Map No. 89, as “P/O 110 , taken for Interstate 95” (see Figure 11) [10; 12; 18, pp. 5 - 6 ; 28, p. 19, 63] . O ne additional background sediment sample (SD - 03) was collected from a location immediately southwest of the Walton & Lonsbury Inc. property, from a property depicted on the City of Attleboro, MA Tax Assessor’s Map No. 59, as Lot Nos. 185 to 190 (land taken for Interstate Routes 95 and 295) (see Figure 11) [10; 12; 18, p. 9;Surface Water Overland Flow General

Walton & Lonsbury Inc. 102 HRS Documentation Record MAD001197755 5 September 2012 28, pp. 23, 63; 68]. Background sediment sample SD - 03 was collected immediately downstream of the discharge point for an outfall pipe , which emerg es from a retaining wall of a property located immediately adjacent to and west of the Walton & Lonsbury Inc. property [18, pp. 9; 28, pp. 23, 63]. Water from the outfall pipe was observed to discharge direct ly into the wetland located south of the Walton & Lonsbury Inc. property [18, p. 9]. Based on information provided in a previous report, the outfall pipe discharges stormwater runoff from the industrial park area west of the Walton & Lonsbury Inc. property [2 4 , p. 15 ]. In addition to the three background sediment samples, five release sediment samples (SD - 04B and field duplicate SD - 08B, SD - 05A, SD - 06A, and SD - 07A) were collected during the 2012 EPA SR from the wetland located south of the Walton & Lonsbury Inc. property [ 18, pp. 4 - 7 , 9, 11 - 12 ; 28, pp. 18 - 20 , 22 - 23, 63 - 65 ]. Background sediment samples SD - 01C and SD - 01D were collect ed in the vicinity of the site from a similar wetland environment as sediment samples SD - 04B, SD - 05A, SD - 06A, SD - 07A, an d SD 08B [ 18, p p . 5 - 6 ]. The three background sediment samples (SD - 01C, SD - 01D, and SD - 03) were collected from the same depth interval (0 to 2 feet), during the same time period , and utilizing the same collection and analytical methods as the five release s ediment samples collected from the wetland south of the Walton & Lonsbury Inc. property [ 18, pp. 4 - 7 , 9, 11 - 12 ; 28, pp. 18 - 20 , 22 - 23, 63 - 65; 32, p. 10 ; 35, pp. 179 - 180, 183 , 185 - 186, 188, 190; 54, p. 1; 64, p. 1 ]. The background sediment s amples were submitted to a CLP l aboratory for chromium and lead analysis under CLP SOW ISM01.3 [18, pp. 11 - 12; 32, p. 10; 64, pp. 1, 9]. COCs for all samples collected as part of the 2012 EPA SR and presented in this HRS d ocumentation r ecord are provided in Reference 32. The applicable COC pages for the background sediment samples, and all corresponding sample identifiers, are provided in available COC and field notes reference documentation [ 18, pp. 5 - 6 , 9, 11 - 12; 32, p. 10]. In addition, all sample IDs and associated sample numbers and COC numbers are provided in a reference table [115]. The analytical data for background sediment samples were validated on a Tier II level according to EPA Region I Tiered Organic and Inorganic Data Validation Guidelines [ 64, pp. 1, 4] . I n addition, the validation was conducted independently by designated chemists who were not involved in the sample collection and HRS evaluation [35, pp. 179 - 180, 183; 64, pp. 1, 4]. The background sediment samples were used to establish background conditions and chemical compositions of the sediment materials within the vicinity of the Walton & Lonsbury Inc. property ; and to establish the range of concentrations for naturally occurring metals in local sediment s upstream of the Walton & Lonsbury Inc. overland flow surface water pathway. Analytical results of the background sediment samples are presented to establish naturally occurring and/or representative background concentrations for lead and chromium, which are used to demonstrate that significant concentration s of these hazardous substance s have been detected in the five release sediment samples collected from the wetland located south of the Walton & Lonsbury Inc. property . The three background sediment samples collected as part of the EPA SR contained varying compositions of naturally occurring native matrix mat erials [35, pp. 179 - 180, 183]. T he compositions of background and contaminated sediment sample s contained similar native matrix materials [35, pp. 179 - 180, 183, 185 - 186, 188, 190]. Sed iment sample SD - 01C was described as saturated, dark brown, organics and silt, trace fine - to - coarse sand, trace fine - to - medium gravel [ 35, p. 179 ]. Sediment sample SD - 01D was described as saturated, brown - to - olive green, silt and organics, little clay, lit tle fine - to - coarse sand, trace fine - to medium gravel [ 35, p. 180 ] . Sediment sample SD - 03 was described as saturated, brown - to - cinnamon brown, fine to coarse sand, little fine - to - medium gravel, trace organics, trace silt [ 35, p. 183 ] .Surface Water Overland Flow General

Walton & Lonsbury Inc. 103 HRS Documentation Record MAD001197755 5 September 2012 Table 4 3 – Background Sediment Sample Location Description s Sample ID Sample Medium Sample Location * Depth (bgs) Date References SD - 01C Wetland Sediment Wetland Sample Location southwest of the Walton & Lonsbury Inc. property (Map No. 89, Lot. No. 110) 0 to 12 inches 25 Jan. 2012 12; 28, p. 63; 35, p. 179; 103, p. 8 SD - 01D Wetland Sediment Wetland Sample Location southwest of the Walton & Lonsbury Inc. property (Map No. 89, Lot. No. 110) 0 to 12 inches 25 Jan. 2012 12; 28, p. 63; 35, p. 180; 103, p. 8 SD - 03 Wetland Sediment Wetland Sample Location immediately southwest of the Walton & Lonsbury Inc. property ( Map No. 59, Lot Nos. 185 to 190) 0 to 3 inches 26 Jan. 2012 28, p. 63; 35, p. 183; 68; 103, p. 8 bgs = Below G round Surface Jan = January No. = Number

* = Sample locations SD - 01C and SD - 01D were located on a property identified on the City of Attleboro Tax Assessor’s Map No. 89 as “P/O 110, taken for Interstate 95” [12]. Sample location SD - 03 was located on a property identified on the City of A ttleboro Tax Assessor’s Map No. 59 as “all of 185 to 190 taken for Interstate Routes 95 and 295” [68]. Among the three background sediment samples , chromium was detected at a maximum concentration of 9.9 J mg/Kg in samples SD - 01C and SD - 03 ; and lead was detected at a maximum concentration of 35.8 J mg/Kg in sample SD - 01C [ 18, pp. 5 - 6 , 9, 11 - 12; 28, p. 63; 64, p. 9; 73, pp. 7, 53, 54, 58 ]. Table 44 – Hazardous Substances Associated with Background Sediment Samples Sample ID Hazardous Substance Hazardous Substance Concentration Bias * Sample Adjusted

CRQL Reference SD - 01C Chromium 9.9 J (12.8) mg/Kg Unknown 2 mg/Kg 18, pp. 5 - 6, 11 - 12; 28, p. 63 ; 64, p. 9 ; 73, p p . 1 - 2, 7 , 53 Lead 35.8 J (51.6) mg/Kg Unknown 2 mg/Kg SD - 01D Chromium 8.5 J (11) mg/Kg Unknown 1.1 mg/Kg 18, pp. 5 - 6, 11 - 12; 28, p. 63 ; 64, p. 9 ; 73, p p . 1 - 2, 7 , 54 Lead 8.6 J (12.4) mg/Kg Unknown 1.1 mg/KgSurface Water Overland Flow General

Walton & Lonsbury Inc. 104 HRS Documentation Record MAD001197755 5 September 2012 Table 44 – Hazardous Substances Associated with Background Sediment Samples SD - 03 Chromium 9.9 J (12.8) mg/Kg Unknown 0.9 mg/Kg 18, pp. 9, 11 - 12; 28, p. 63 ; 64, p. 9 ; 73, p p . 1 - 2, 7 , 58 Lead 14 .0 J (20.2) mg/Kg Unknown 0.9 mg/Kg CRQL = Contract Required Quantitation Limit mg/Kg = Milligrams per Kilogram J = The associated numerical value is an estimated quantity and the bias resulting from the estimate has been considered as explained below [73, p. 7]. ( ) = For hazardous substance concentrations, denotes concentration of the compound or element following adjustment based on the EPA Fact Sheet, Using Qualified Data to Document an Observed Release and Observed Contamination [70 ]. * An explanation for the direction of the bias is provided in Reference 73, Table 1. For h azardous substances detected in background sediment samples above the sample - adjusted CRQL , an observed release is established when the release sample concentration is three times or more above the background concentration [1, p. 51589 (Table 2 - 3)]. F or sediment samples presented in this HRS documentation record , background comparison criteria fo r a hazardous substance are established at greater than or equal to three times the highest concentration of that hazardous substance detected among the three background sediment samples (SD - 01C, SD - 01D, and SD - 03) [1, p. 51589, Table 2 - 3]. For the purpose s of this HRS documentation record , concentrations of chromium and lead detected in release sediment samples SD - 04B, SD - 05A, SD - 06A, SD - 07A, and SD - 08B, at levels greater than or equal to three times the highest background concentration for chromium and le ad, are used to document an observed release to the wetland located south of the Walton & Lonsbury Inc. property [1, pp. 51588, Section 2.2, 51589, Table 2 - 3]. Contaminated Samples: On 25 and 26 Januar y 2012, as part of the EPA SR and in accordance with the EPA - approved January 2012 Site - Specific QAPP , sediment sampling activities were conducted in the HRS - eligible wetland located south of the Walton & Lonsbury Inc. property [18, pp. 4 - 5, 7, 9, 11 - 12; 28, pp. 18 - 20, 22, 64 - 65; 31, p p. 1, 26, 30, 36, 38 ]. Five release sediment samples (SD - 04B and field duplicate SD - 08B, SD - 05A, SD - 06A, and SD - 07A) were collected from the wetland, at depths down to 2 feet bgs [28, pp. 64 - 65; 35 , pp. 185 - 186, 188, 190]. Locations of the sediment samples collected from the wetland located south of the Walton & Lonsbury Inc. property are depicted in Figure 11. R elease sediment sample compositions contained native matrix materials similar to the backgrou nd sediment samples [35, pp. 179 - 180, 183, 185 - 186, 188, 190]. Sediment sample SD - 04B and field duplicate sample SD - 08B were described as saturated, dark brown - to - olive, organics and silt, little fine to - coarse sand, trace clay [35, p. 185] . Sediment sampl e SD - 05A was described as wet, dark brown, organics, some silt, trace clay, trace fine - to - coarse sand [35, p. 186] . Sediment sample SD - 06A was described as saturated, dark brown, organics, some silt, little clay, trace fine - to - coarse sand [35, p. 188] . Sediment sample SD - 07A was described as wet, dark brown, silt and fine - to - coarse sand, some organics, trace clay, trace fine - to - medium gravel [35, p. 190] . The five release sediment samples (SD - 04B, SD - 05A, SD - 06A, SD - 07A, and SD - 08B) were submitted to a CLP l aboratory for chromium and lead analysis under CLP SOW ISM01.3 [18, pp. 11 - 12; 32, p. 10; 54, pp. 1, 9; 64, pp. 1, 9]. COCs for all samples collected as part of the 2012 EPA SR and presented in thisSurface Water Overland Flow General

Walton & Lonsbury Inc. 105 HRS Documentation Record MAD001197755 5 September 2012 HRS d ocumentation r ecord are provided in Reference 3 2. The applicable COC pages for the release sediment samples, and all corresponding sample identifiers, are provided in available COC and field notes reference documentation [18, pp. 4 - 5, 7, 9, 11 - 12; 32, p. 10]. In addition, all sample IDs and associated sample numbers and COC numbers are provided in a reference table [115]. The analytical data for the five release sediment samples were validated on a Tier II level according to EPA Region I Tiered Organic and Inorganic Data Validation Guidelines [ 54, pp. 1 , 5; 64, p. 1, 4] . I n addition, the validation was conducted independently by designated chemists who were not involved in the sample collection and HRS evaluation [35, pp. 185 - 186, 188, 190; 54, pp. 1, 5; 64, p. 1, 4]. T he release sediment samples were collected from similar depths as the background sediment samples, contained similar matrix material s as the background sediment samples, and were collected and analyzed using the same methods as the background sediment samples [18, pp. 11 - 12; 32, p. 10; 35 , pp. 179 - 180, 183, 185 - 186, 188, 190; 54, pp. 1, 9; 64, pp. 1, 9]. Table 4 5 – Sediment Sample Location Description s Sample ID Sample Medium Sample Location * Distance from PPE No. 2 (miles) Depth (bgs) Date References SD - 04B Wetland Sediment Wetland south of the Walton & Lonsbury Inc.

property ( Map No. 59, Lot Nos. 185 to 190) 0.054 0 to 12 inches 26 Jan. 2012 28, p. 64 ; 35, p. 185; 87; 68 SD - 05A Wetland Sediment Wetland south of the Walton & Lonsbury Inc.

property ( Map No. 59, Lot No. 142) 0.133 0 to 12 inches 25 Jan. 2012 28, p. 64 ; 35, p. 186; 87; 68 SD - 06A Wetland Sediment Wetland south of the Walton & Lonsbury Inc.

property ( Map No. 59, Lot No. 220) 0.158 0 to 12 inches 25 Jan. 2012 28, p. 64 ; 35, p. 188; 87; 68 SD - 07A Wetland Sediment Wetland south of the Walton & Lonsbury Inc.

property ( Map No. 59, Lot No. 220) 0.188 18 to 24 Inches 25 Jan. 2012 28, p. 65 ; 35, p. 190; 87; 68 SD - 08B Wetland Sediment Wetland south of the Walton & Lonsbury Inc.

property ( Map No. 59, Lot Nos. 185 to 190) 0.054 0 to 12 inches 26 Jan. 2012 28, p. 65 ; 35, p. 185; 87; 68 bgs = Below Ground Surface Jan. = January No. = Number * = The Lot numbers provided are depicted on the City of Attleboro Tax Assessor’s Map No. 59 [68] . Among the five release sediment samples, chromium was detected at a maximum concentration of 28,300 J mg/Kg in sediment sample SD - 06A, and lead was detected at a maximum concentration of 1,310 J mg/Kg in sediment sample SD - 05A [18, pp. 4 - 5, 7, 9, 11 - 12; 28, pp. 64 - 65; 54, p. 9; 64, p. 9 ; 73, pp. 8, 57, 59 - 60; 74, pp. 7, 51 - 52 ].Surface Water Overland Flow General

Walton & Lonsbury Inc. 106 HRS Documentation Record MAD001197755 5 September 2012 Table 46 – Hazardous Substances Associated with Sediment Samples Sample ID Hazardous Substance Hazardous Substance Concentration Bias * Sample Adjusted

CRQL Reference SD - 04B Chromium 2,320 J (1,798) mg/Kg Unknown 1 mg/Kg 18, pp. 9, 11 - 12; 64, p. 9 ; 73, p p. 1 - 2, 8 , 59 SD - 05A Chromium 26,500 J (20,540) mg/Kg Unknown 10 mg/Kg 18, pp. 7, 11 - 12; 54, p. 9 ; 74, p p . 1 - 2, 7 , 5 1 Lead 1,310 J (910) mg/Kg Unknown 1 mg/Kg SD - 06A Chromium 28,300 J (21,940) mg/Kg Unknown 10 mg/Kg 18, pp. 5, 11 - 12; 54, p. 9 ; 74, p p. 1 - 2, 7 , 5 2 Lead 539 J (374) mg/Kg Unknown 1 mg/Kg SD - 07A Chromium 4,860 J (3,767) mg/Kg Unknown 2.4 mg/Kg 18, pp. 4, 11 - 12; 64, p. 9 ; 73, p p . 1 - 2, 8 , 57 Lead 250 J (174) mg/Kg Unknown 2.4 mg/Kg SD - 08B Chromium 4,320 J (3,349) mg/Kg Unknown 1.4 mg/Kg 18, pp. 9, 11 - 12; 64, p. 9 ; 73, p p . 1 - 2, 8 , 60 Lead 342 J (238) mg/Kg Unknown 1.4 mg/Kg CRQL = Contract Required Quantitation Limit. mg/Kg = Milligrams per K ilogram J = The associated numerical value is an estimated quantity [73, p. 8; 74, p. 7]. ( ) = For hazardous substance concentrations, denotes concentration of the compound or element following adjustment based on the EPA Fact Sheet, Using Qualified Data to Document an Observed Release and Observed Contamination [70]. * An explanation for the direction of the bias is provided in Reference 73, Table 2 and Reference 74, Table 1. Attribution: T he operational history of the Walton & Lonsbury Inc. property as a chromium electroplating facility , as well as analytical sampling data that demonstrate the presence of the hazardous substances lead and chromium in source areas, establishes that lead and chromium are associated with the site. C hromium electroplating operation s were conducted on the Walton & Lonsbury Inc. property between 1940 and 2007 [15 , p. 2 ; 23 , pp. 5 - 6 ]. In a 1983 Facility Annual Report submitted to the Commonwealth of Massachusetts, Walton & Lonsbury Inc. identified that “chrome sludge from plating process ” was generated at a rate of 1,500 gallons a year [81, pp. 1, 7]. According to a chemical use inventory list included in a 1989 report prepared by RCA, on behalf of Walton & Lonsbury Inc., hazardous c hemicals used at the property included chromic acid [24 , pp. 16 - 17 , 77 ]. A 1989 Annual Report prepared by Walton & Lonsbury Inc. identified the facility as a large quantity generator and on - site treatment, storage, or disposal facility generating “chrome plating rinse water” and “sludge” at a rate of 10,800 g a llons perSurface Water Overland Flow General

Walton & Lonsbury Inc. 107 HRS Documentation Record MAD001197755 5 September 2012 year [85, pp. 1 - 2, 10]. A 1991 Hazardous Waste Report submitted by Walton & Lonsbury Inc. to EPA identified on - site wastes generated including “corrosive chromic - acid - contaminated solid debris, from chrome - plating operation”; “ chromic acid in wat er ” ; and “chromic - acid contaminated steel ductwork ventilation system for chrome - plating operation” [86, pp. 1, 3 - 4, 7 ]. File documentation indicates that in 2007, 4,200 gallons of chromic acid solution were transported from the Walton & Lonsbury Inc. prop erty for disposal and/or treatment , and a 2008 hazardous waste manifest documents the transport of 4,010 gallons of chromic acid from the Walton & Lonsbury Inc. property in Attleboro, MA [80, pp. 26, 28 ; 84 ]. Lead has also been identified as having been used in former operational processes on the property [15 , pp. 2 - 3]. The Walton & Lonsbury Inc. facility building contained a lead smelter and exhaust hood that were associated with the manufacture of plumbing co mponents in volved in the plating process [15, p. 3]. Chemical analysis of source samples collected from Source Nos. 1 and 2 have documented the presence of the hazardous substances chromium, hexavalent chromium, and lead [28, pp. 61 - 62; 50, pp. 9 - 10; 5 2, p. 8; 72, pp. 9 - 21, 72, 73; 77, pp. 11, 72, 73]. Analytical sampling data for Source No s . 3 and 4 have documented the presence of chromium and lead at concentrations significantly above background [28, p p. 64 , 67, 69

– 73, 83 ; 53, p. 9; 54, p. 9; 60, pp. 7, 8; 72, pp. 33, 34, 36, 37, 42 - 46, 63, 74, 75, 78; 74, pp. 7, 51 - 52]. Chemical analysis of five sediment samples (SD - 04B, SD - 05A, SD - 06A, SD - 07A, and SD - 08B) document an observed release to the HRS - eligible wetland adjacent to or downstream of , a nd subject to overland flow from , Source Nos. 1 through 4 [ 28, pp. 64 - 65; 54, p. 9; 64, p. 9; 73, pp. 8, 57, 59 - 60; 74, pp. 7, 5 1 - 52 ]. The presence of chromium and lead at elevated concentrations in Sources 1 through 4 , and the documentation via chemical analysis of an observed release of these substances to the wetland south of the Walton & Lonsbury Inc. property , support at least partial attribution of the hazardous substances to releases from the site [1, p. 51588, Section 2.2 .2]. A review of available information was conducted to determine other potential sources of chromium and lead contamination to the site . This review included a search of the Searchable Waste Site List/ Site Files for M assDEP, and a review of the EPA Comprehensive Environmental Response, Compensation and Liability Information System ( CERCLIS ) and Resource Conservation and Recovery Act ( RCRA ) databases. The MassDEP database allows sites and reportable releases to be searched by various criteria, and all ows users to retrieve a report once the associated data have been approved by MassDEP for public viewing. As part of the search for other nearby potential chromium and lead sources , the MassDEP database was queried for records for the “Town of Attleboro”. A total of 309 spill records were identified based on this criterion [102, pp. 1 - 7]. The search was further refined to include reportable releases within 1⁄2 - mile of the Walton & Lonsbury Inc. property. The search yielded 25 records of reportable releases o n the following streets: Walton Street, Deanville Road, Holden Street, Newcomb Street, Water Street, West Street, Townhouse Road, and North Avenue. The majority (14 records) listed “oil” as the chemical type; six records listed “hazardous material” as the chemical type; one record listed “oil and hazardous material” as the chemical type; and four records did not list the chemical type. Three of these releases are associated with the Walton & Lonsbury Inc. property [102, pp. 1 - 3]. A review of the online documentation of the remaining incidents involving oil and hazardous materials or undefined contaminants (excluding releases from the Walton & Lonsbury Inc. property) indicated that none of the incidents involved or identified the pr esence of chromium or lead above background levels [93, pp. 35 - 40; 94, pp. 39 - 40; 95, p. 37; 96, pp. 23 - 25; 97, p. 16; 98, pp. 3 - 6; 99, p. 6; 100, p. 10; 101, pp. 28 - 29; 116, p. 1; 117, pp. 13 - 16, 226, 231 - 232; 118, p. 1; 119, p. 11]. A review of the EPA CERCLIS and RCRA databases identified eight CERCLIS and 188 RCRA sites in Attleboro, MA, in cluding Walton & Lonsbury Inc. [104, pp. 1 - 2; 105, pp. 1 - 73]. The seven remaining sites identified in the CERCLIS database search (other than Walton & Lonsbury Inc. ) were all located downstream or south of the Walton & Lonsbury Inc. property, and two of the facilities were located greater than 4 miles from the Walton & Lonsbury Inc. property [11; 106, pp. 1 - 4]. The RCRA database search was further refined to include only North American Industry Classification (NAIC) Code 332813Surface Water Overland Flow General

Walton & Lonsbury Inc. 108 HRS Documentation Record MAD001197755 5 September 2012 (electroplating). The search identified seven electroplating fa cilities, including the Walton & Lonsbury Inc. property [106, pp. 1 - 4]. The remaining six facilities identified in the RCRA databa se search were located downstream or south of the Walton & Lonsbury Inc. property [11; 106, pp. 1 - 4]. As part of the 2012 EPA SR , background sediment sample locations SD - 01C, SD - 01D, and SD - 03 were selected to further identify any additional potential ly contributing sources of chromium and lead contamination to the wetland south of the Walton & Lonsbury Inc. property. Background sediment samples SD - 01C and SD - 01D were collected from a tributary upstream of the wetland [18, p. 6 ]. This tributary was ob served to flow along the southe rn border of several industrial/ commercial properties along Walton Street, west of the Walton & Lonsbury Inc. property , prior to discharging to the wetland south of the property [18 , pp. 5 - 6]. No other tributaries were observ ed to flow into the wetland south of the Walton & Lonsbury Inc. property [18, pp. 5 - 6]. Background sediment sample SD - 03 was collected immediately downstream of the discharge point of an outfall pipe , which emerg ed from a retaining wall of a property locat ed immediately adjacent to and west of the Walton & Lonsbury Inc. property [18, pp. 9; 28, pp. 23, 63]. Water from the outfall pipe was observed to discharge directly into the wetland located south of the Walton & Lonsbury Inc. property [18, p. 9]. Based on information provided in a previous report, the outfall pipe discharges stormwater runoff from the industrial park area west of the Walton & Lonsbury Inc. property [2 4 , p. 15 ]. As presented above, analytical results of background sediment sample s SD - 01C, SD - 01D, and SD - 03 indicated that no significant levels of lead and chromium contamination are entering the wetland from upstream tributaries or the outfall pipe [ 18, pp. 5 - 6, 9, 11 - 12; 28, p. 63; 64, p. 9; 73, pp. 7, 53, 54, 58 ]. Hazardous Substa nces Released Chromium and lead (by chemical analysis) Surface Water Observed Release Factor Value: 550 4.1.2.1.2 Potential to Release An observed release was documented through chemical analysis; therefore , potential to release was not evaluated. 4.1.2.2 Drinking Water Threat Waste Characteristics Drinking Water Threat Targets have not been identified for the surf ace water overland flow pathway; therefore , the Drinking Water Threat was not evaluated . 4.1.2.3 Drinking Water Threat Targets Drinking Water Threat Targets have not been identified for the surface water ov erland flow pathway; therefore, Drinking Water Threat Targets w ere not evaluated . 4.1.3.2 Human Food Chain Threat Waste Characteristics There are p otential Human F ood Chain Threat Targets due to the presence of a potential fishery located along the downstream surface water pathway, and previous documentation of contaminated downstream sediments within the reach of the potential fishery [25, pp. 33, 35, 61 ; 28, p. 41 ]. However, evidence of fish cons umption has not been documented; therefore , the Human Food Chain Threat has not been evaluated as part of this HRS documentation record .Surface Water Overland Flow General

Walton & Lonsbury Inc. 109 HRS Documentation Record MAD001197755 5 September 2012 4.1.3.3 Human Food Chain Threat Targets There are p otential Human Food Chain Threat Targets due to the presence of a potential fishery located along the downstream surface water pathway, and previous documentation of contaminated downstream sediments within the reach of the potential fishery [25, pp. 33, 35, 61 ; 28, p. 41]. However, evid ence of fish consumption has not been documented; therefore, the Human Food Chain Threat has not been evaluated as part of t his HRS documentation record. 4.1.4.2 Environmental Threat Waste Characteristics 4.1.4.2.1 Ecosystem Toxicity/Persistence/Bioaccumulation The Ecosystem Toxicity Factor Value and the Persistence Factor Value are assigned to the hazardous substances associated with the sources and releases at the site based on the values presented in the Superfund Chemical Data Matrix ( SCDM ) [2, pp . BI - 3, BI - 8]. Since the downstream hazardous substance migration pathway s are comprised of fresh water bodies, ecosystem toxicity and bioaccumulation factor values for fresh water are used in this evaluation . Since the upstream a nd downstream hazardous substance migration pathways are comprised of rivers, persistence values for rivers are used in this evaluation . Table 47 - Ecosystem Toxicity/Persistence/Environmental Bioaccumulation Factor

Hazardous Substance Source No s . Ecosystem Toxicity Factor Value Persistence Factor Value Environmental Bioaccumulation Value Ecosystem Toxicity/ Persistence/ Environmental Bioaccumulation

Factor Value (Ref. 1, Table 4 - 21) References Chromium 1, 2, 3 , 4 10,000 1.0 500 5 × 10 6 2, p. BI - 3 Lead 1, 2, 3 , 4 1,000 1.0 50,000 5 × 10 7 2, p. BI - 8 From HRS Table 4 - 21, a Ecosystem Toxicit y/Persistence Factor Value of 1 ,000 and a Environmental Bioaccumulation Factor Value of 5 0, 00 0 for lead are assigned an Ecosystem Toxicity/Persistence/ Bioaccumulation Factor Value of 5 × 10 7 [1, p. 51623]. Ecosystem Toxicity/Persistence/Environmental Bioaccumulation Factor Value: 5 × 10 7 4.1.4.2.2 Hazardous Waste Quantity Table 4 8 – Hazardous Waste Quantity Factor Source No. Source Type Source Hazardous Waste Quantity 1 Pile 4 69 .2 2 Pile 760 3 Surface Impoundment 10,0 29.9 4 Contaminated Soil 0.36Surface Water Overland Flow General

Walton & Lonsbury Inc. 110 HRS Documentation Record MAD001197755 5 September 2012 Sum of Values: 11, 2 59 . 46 Based on HRS Section 2.4.2.2, if the Hazardous Constituent Quantity is not adequately determined for one or more sources and if any target for the surface water pathway is subject to Level I or Level II concentrations, a factor value is assigned from Table 2 - 6 or a value of 100, whichever is greater, a s the Hazardous Waste Quantity Factor Value for tha t pathway [1, pp. 51591, Table 2 - 6, 51592, Section 2.4.2.2]. Hazardous Waste Quantity Factor Value ( 1, p. 51591, Table 2 - 6 ): 1 0,000 4.1.4.2.3 Waste Characteristics Factor Category Value The Ecosystem Toxicity Factor Value (1 ,0 00) and the Persistence Factor Value (1 .0 ) for lead are multiplied in order to determine the Ecosystem Toxicity/Persistence Factor Value (1 ,0 00) [1, p. 51624, Se ction 4.1.4.2.1.4, Table 4 - 20]. The Ecosystem Toxicity/Pers istence Factor Value for the watershed (1 ,0 00) is multiplied by the Hazardous Waste Quantity Factor Value for the watershed (10 ,000 ) in order to determine the Waste Characteristics Product, subject to a maximum value of 1 × 10 8 [1, pp. 51592, Section 2.4.3 .1, 51624, Section 4.1.4.2.3]. 1 ,0 00 × 10 ,000 = 1 × 10 7 . Ecosystem Toxicity/Persistence Factor Value: 1 ,000 Hazardous Waste Quantity Factor Value: 10,000 Ecosystem Toxicity/Persistence Factor Value × Hazardou s Waste Quantity Factor Value: 1 × 10 7 The Waste Characteristics Product for the watershed (subject to a maximum value of 1 × 10 8 ) is multiplied by the Bioaccumulati on Potential Factor Value (5 0, 0 0 0 ) for lead , to generate a second product, subject to a maximum value of 1 × 10 12 [1, p. 51624, Se ction 4.1.4.2.3]. ( 1 × 10 7 ) × 5 0,0 00 = 5 × 10 1 1 . (Ecosystem Toxicity/Persistence × Hazardous Waste Quantity) × Bioaccumula tion Potential Factor Value: 5 × 10 1 1 From HRS Table 2 - 7, the second Waste Characteristics Product (5 × 10 1 1 ) is assigned a Wast e Characteri stics Factor Category Value of 560 [1, pp. 51592, Section 2.4.3.1, 51624, Section 4.1.4.2.3]. Waste Characteristics Factor Category Value ( 1, p. 51592, Table 2 - 7 ): 560 4.1.4.3 Environmental Threat Targets The United States Fish and Wildlife Service (USFWS) National Wetland Inventory (NWI) documents numerous wetland types along the TDL for the surface water migration pathway for the Walton & Lonsbury Inc. site [103, pp. 2, 9]. According to the NWI maps, wetl ands are present in the area south and southwest of the Walton & Lonsbury Inc. property , extending from PPE No. 2 to immediately north of Deanville Road ; and east of the Walton & Lonsbury Inc. property , along Bliss Brook [103, p p . 3 , 9 ]. On 10 January 2012, an EPA Senior Wetland Scientist examined and delineated the wetland area e x te nding downstream of PPE No. 2 to Deanville Road [103, p. 3]. The results of th is wetland delineation indicated that the shape of the wetland outlined by the NWI Maps was generally consistent with what was observed in the field; however , various wetland types were identified within this wetland area, rather than the single classification identified by the NWI maps [103, pp. 3, 9, 10]. The results of the EPA we tland delineation documented several classifications of HRS - eligible wetlands south of the Walton & Lonsbury Inc. property [103, pp. 3, 10, 26]. The results of the EPA wetland delineation documented a total area of 8.5 acres of HRS - eligible wetlands south of the Walton & Lonsbury Inc. property and north of DeanvilleSurface Water Overland Flow General

Walton & Lonsbury Inc. 111 HRS Documentation Record MAD001197755 5 September 2012 Road , with a total perimeter of 0.811 miles (see Figure 11) [103, pp. 10, 26]. In addition, field observations indicated that there was no discernible flow ( e.g. defined channel) through this wetland area [103, p. 4] . Additional segments of HRS - eligible wetlands were identified along Bliss Brook, the Bungay River, and the Ten Mile River (including Mechanics Pond) [103, pp. 3 - 5, 10, 26 - 27]. For the purposes of this HRS documentation record , onl y the downstream wetland extending south of the Walton & Lonsbury Inc. property to immediately north of Deanville Road , which is subject to actual contamination , is evaluated to document actual contamination to greater than 0.1 miles of wetland frontage. Analytical results of five sediment samples (SD - 04B, SD - 05A, SD - 06A, SD - 07A, and SD - 08B), collected during the EPA SR from the HRS - eligible wetland south of the Walton & Lonsbury Inc. property , document an observed release of chromium and lead [ 28, pp. 64 - 65; 54, p. 9; 64, p. 9; 73, pp. 8, 57, 59 - 60; 74, pp. 7, 51 - 52 ]. Sediment sample SD - 07A was collected at a location 0.188 miles downstream of the most upstream PPE (PPE No. 2) for surface water overland flow to the wetland [87, p. 1]. Most Distant Level I Sample Sample ID: N/A Distance from the probable point of entry: Reference: Most Distant Level II Sample Sample ID: SD - 07A Distance from the probable point of entry: 0.188 miles Reference: 28, p. 18 ; 64, p. 9; 65; 73, pp. 8, 57; 87, p. 1 4.1.4.3.1 Sensitive Environments 4.1.4.3.1.1 Level I Concentrations The observed release to sediment from sources associated with the Walton & Lonsbury Inc. property is established by sediment sample analytical results [ 54, p. 9; 64, p. 9; 73, pp. 8, 57, 59 - 60; 7 4, pp. 7, 51 - 52 ]. Sensitive environments that are determined to be actual contamination targets based on sediment sample analytical results, but for which no ecological - based benchmarks are applicable, are evaluated as subject to actual contamination at Le vel II [1, p. 51625, Section 4.1.4.3.1]. No Level I sensitive environments have been identified. Sum of Level I Wetland Frontages: Wetlands Value (Ref. 1, Table 4 - 24): 0 Sum of Level I Sensitive Environments Value + Wetlands Value: (Sum of Level Sensitive Environments Value + Wetlands Value) x 10: 0 Level I Concentrations Factor Value: 0 4.1.4.3.1.2. Level II Concentrations One sensitive environment ( HRS - eligible wetland located south of the Walton & Lonsbury Inc. property and extending to immediately north of Deanville Road ), which was determined t o be an actual contamination target based on chemical analysis of sediment samples , is e valuated using Level II concentrations [1, p. 51625, Section 4.1.4.3.1]. An observed release t o sediment from sources associated with the Walton & Lonsbury Inc. property has been established for the entire wetland located south of the Walton & Lonsbury Inc. property , e ncompassing an area bounded by 0.811 miles of wetland frontageSurface Water Overland Flow General

Walton & Lonsbury Inc. 112 HRS Documentation Record MAD001197755 5 September 2012 downstream of PPE No. 2 [54, p. 9; 64, p. 9; 73, pp. 8, 57, 59 - 60; 74, pp. 7, 51 - 52 ; 103, pp. 9, 26 ]. No other sensitive environments were evaluated along the TDL for the surface water migration pathway for the Walton & Lons bury Inc. site . Level II Wetland Frontages Based on the results of the January 2012 EPA wetland delineation activities, a total area of 8.5 acres of HRS - eligible wetlands with a total perimeter of 0.811 miles w as identified in the downstream wetland so uth of the Walton & Lonsbury Inc. property and extending to immediately north of Deanville Road [103, pp. 10, 26]. In addition, field observations indicated that there was no discernible flow ( e.g. defined channel) through t his wetland [103, p. 4] . For the purposes of this HRS documentation record , only the HRS - eligible wetland south of the Walton & Lonsbury Inc. property and subject to actual contamination is evaluated to document actual contamination to greater than 0.1 miles of wetland frontage. Chromium was detected through laboratory analysis at concentrations documenting an observed release in each of the five sediment samples (SD - 04B, SD - 05A, SD - 06A, SD - 07A, and SD - 08B) collected from the downstream wetland located south of the Walton & Lonsbu ry Inc. property and extending to immediately north of Deanville Road [1, p. 51588 ( Section 2.2.2 ), p. 51609 ( Section 4.1.2.1.1 ) ; 28, p p . 64, 65; 54, p. 9; 64, p. 9; 73, pp. 8, 57, 59 - 60; 74, pp. 7, 51 - 52 ]. Lead was detected through laboratory analysis at concentrations documenting an observed release in four of the five sediment samples (SD - 05A, SD - 06A, SD - 07A, and SD - 08B) collected from th is wetland [ 1, p. 51588, Section 2.2.2, p. 51609, Section 4.1.2.1.1; 28, p p. 64 - 65; 54, p. 9; 64, p. 9; 73, pp. 8, 57, 59 - 60; 74, pp. 7, 51 - 52 ]. N o discernible flow ( e.g. defined channel) was observed through this wetland , and observed contamination via chemical analysis was documented in sediment samples collected from the northern boundary of the wetland (SD - 04B/SD 08B) , throughout the wetland (SD - 05A and SD - 06A) , and to the southeastern boundary of the wetland (SD - 07A) , to where surface water flow is directed into an underground culvert (see Figure 11) [ 28, p p. 64 - 65; 54, p. 9; 64, p. 9; 73, pp. 8, 57, 59 - 60; 74, pp. 7, 51 - 52 ; 103, p. 4]. Therefore, a n HRS - eligible wetland perimeter frontage of 0.811 miles is documented as a Level II actual observed release environmental target [1, pp. 51589 (Table 2 - 3), 51625 (Section 4.1.4.3.1)]. Table 49 – Wetland Frontages Wetland Wetland Frontage (miles) References Wetland located south of the Walton & Lonsbury Inc. property 0.811 54, p. 9; 64, p. 9; 73, pp. 8, 57, 59 - 60; 74, pp. 7, 51 - 52 ; 103, pp. 9, 26 Sum of Level II Wetland Frontages: 0.811 miles Wetlands Value ( 1, p. 51625, Table 4 - 24 ): 25 Sum of Level II Sensitive Environments Value + Wetlands Value: 25 Level II Concentrations Factor Value: 25Surface Water Overland Flow General

Walton & Lonsbury Inc. 113 HRS Documentation Record MAD001197755 5 September 2012 4.1.4.3.1.3 Potential Contamination Potential Sensitive Environment Targets Table 50 - Potential Sensitive Environment Targets Type of Surface

Water Body Sensitive Environment References Sensitive Environment Value [1, Table 4 - 23] NS NS = Not Scored. Potential Wetland Frontages Table 51 - Potential Wetland Frontages Type of Surface

Water Body Wetland Frontage (miles) References Wetlands Value [1, Table 4 - 24] NE NS = Not Evaluated. Table 52 - Potential Wetland Frontage Value

Type of Surface

Water Body Sum of Sensitive Environments

Values (Si) Wetland Frontage Value (W j ) Dilution Weight (D j ) D j (W j + S j ) NS NS = Not Evaluated. Sum of D j (W j + S j ): (Sum of D j (W j + S j ))/10: Potential Contamination Factor Value: Not ScoredSoil Exposure Resident Population Threat

Walton & Lonsbury Inc. 1 14 HRS Documentation Record MAD001197755 5 September 2012 5.0 SOIL EXPOSURE PATHWAY 5.0.1 GENERAL CONSIDERATIONS Letter by which these areas are to be identified : A, B, and C Names of areas : Contaminated Soil Area A, Contaminated Soil Area B, Contaminated Soil Area C Location and description of areas (with references to maps of the sites ): Area A: Area of Observed Contamination, Area A (Area A) is equivalent to the area encompassed by Source No. 4 , with the exception of the area covered by essentially impenetrable barrier (Deanville Road), per HRS requirements [1, p. 51646 (Section 5.0.1); 71, pp. 1 - 2, 9 - 10 ] . Area A comprises 11,980.80 ft 2 (0.28 acres) located on portions of seven properties which are located south of the Walton & Lonsbury I nc. property (see Figure s 8 , 12, and 13 ) [10; 12; 65; 66; 71 , pp. 1 - 2, 9 - 10 ]. These seven properties are depicted on the City of Attleboro, MA Tax Assessor’s Map No. 49, as Lot Nos. 113, 114B; and on Map No. 59, as Lot Nos. 190A, 220, 225, 227, 228 [12; 68; 69]. The geographic coordinates of Area A, as measured from its approximate center, are 41° 57 ′ 18.1 ′′ north latitude and 71° 17 ′ 49.3 ′′ west longitude [11; 71 , p. 2 ]. Area A is bounded by the following six surface soil sample locations: P - 01 - SS - 02B, P - 0 1 - SS - 03B, P - 04 - SS - 06, P - 06 - SS - 02, P - 07 - SS - 02/P - 30 - SS - 02 (field duplicate), and P - 09 - SS - 07 [1, p. 51646, Section 5.0.1, 28, pp. 67, 69 - 73, 83; 53, p. 9; 60, pp. 7, 8; 71, pp. 9 - 10 ; 72, pp. 33, 34, 36, 37, 42 - 46, 64, 74, 75, 78, 79 ]. Three additional surfac e soil samples, P - 04 - SS - 03, P - 06 - SS - 03, and P - 09 - SS - 02, are located within Area A [ 28, pp. 69, 71 - 72 ; 71 , pp. 9 - 10 ]. The majority of Area A is located along the western portions of residential properties along North Avenue, adjacent to (east of) the wet land and Surface Impoundment Source Area (Source No. 3) located south of the Walton & Lonsbury Inc. property (see Figure 8). Based on site topography and on - site observations, the low - lying areas on the western portions of residential properties along Nort h Avenue, immediately east of the wetlands located south of the Walton & Lonsbury Inc. property, are subject to surface water flooding from the wetlands [11; 18, pp. 15 - 16, 23 ; 109, p. 1, 5 ]. Area A also includes an area of contaminated soil on portions of two properties (designated during the 2012 EPA SR as “ P - 07 ” and “ P - 09 ” ) located sout h of Deanville Road and the wetland south of the Walton & Lonsbury Inc. property [18, pp. 13 , 15 - 16; 28, pp. 28, 71 - 72]. Low - lying areas in the northern portions of severa l properties along the southern side of Deanville Road, south of the wetland, have been observed to be subject to flooding from surface water flow ing across Deanville Road from the wetland [18, pp. 16, 28]. Area B: Area of Observed Contamination, Area B (Area B) is equivalent to the area encompassed by Source No. 5 , with the exception of areas covered by essentially impenetrable barrier (a shed and a pool), per HRS requirements [ 1, p. 51646 (Section 5.0.1); 71, pp. 1 - 3, 11 - 13 ]. Area B comprises 11,756.69 ft 2 ( 0.27 acres) located on portions of 11 properties located east of the Walton & Lonsbury Inc. property (see Figure s 9 , 14, 15, and 16 ) [10; 12; 65; 66; 71, pp. 1 - 3, 11 - 13 ]. These 11 properties are depicted on the City of Attleboro, MA Tax Assessor’s Ma p No. 49, as Lot Nos. 94, 95, 96, 97, 97A, 102A, 104, 109, 110, 111, and 112 [12; 69]. The geographic coordinates of Area B, as measured from its approximate center, are 41° 57 ′ 14.9 ′′ north latitude and 71° 17 ′ 43.2 ′′ west longitude [11; 71 , p. 3 ]. Area B i s bounded by the following 10 surface soil sample locations: P - 03 - SS - 05, P - 05 - SS - 06, P - 05 - SS - 05, P - 20 - SS - 04A/P - 31 - SS 04A (field duplicate), P - 20 - SS - 01, P - 19 - SS - 03, P - 18 - SS - 07, P - 18 - SS - 08, P - 24 - SS - 04, and P - 17 - SS 07A/B [1, p. 51646, Section 5.0.1, 28, pp. 6 9, 70, 78 - 80, 83; 53, pp. 9, 10; 60, p. 9; 61, pp. 7, 8; 71, pp.Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 115 HRS Documentation Record MAD001197755 5 September 2012 11 - 13 ; 72, pp. 35, 38 - 41, 47 - 54, 64, 76, 78 - 81 ]. Three additional surface soil samples, P - 05 - SS - 01, P - 05 - SS - 04, and P - 18 - SS - 09, are located within Area B [ 28, pp. 70, 79 ; 71 , pp. 11 - 13 ]. Area B is located southeast of the Walton & Lonsbury Inc. property, along the eastern portions of residential properties east of North Avenue and immediately west of Bliss Brook; and along the western portions of residential properties located west of Roun ds Place and immediately east of Bliss Brook [18, pp. 30 - 31, 33 - 36; 28, pp. 49, 69, 70, 78 - 80, 83]. Area B encompasses surface soil sample locations within low - lying areas on residential properties , adjacent to Bliss Brook [18, pp. 17 - 19, 22 - 25]. Based on site topography , flood plain data, on - site observations, and interviews with an on - site resident, the low - lying areas of residential properties within Area B, adjacent to Bliss Brook, are known or suspected to be subject to surface water flooding from Blis s Brook [18, pp. 17 - 19, 22 - 25 ; 109, pp. 1 - 2, 5 ]. Area C: Area of Observed Contamination, Area C (Area C) is equivale nt to the area encompassed by Source No. 6. Area C comprises 4,350.89 ft 2 ( 0.10 acres) located on portions of four properties l ocated southeast of the Walton & Lonsbury Inc. property (see Figure s 10 and 17 ) [10; 12; 65; 66; 71 , pp. 1, 3 - 4, 14 ]. These four properties are depicted on the City of Attleboro, MA Tax Assessor’s Map No. 49, as Lot Nos. 124, 125, 125A, and 126 [12; 69]. The geog raphic coordinates of Area C, as measured from its approximate center, are 41° 57 ′ 6.8 ′′ north latitude and 71° 17 ′ 43.2 ′′ west longitude [11; 71 , p. 4 ]. Area C is bounded by the following five surface soil sample locations: P - 23 - SS - 06, P - 23 - SS - 02, P - 22 - SS - 09A, P - 22 - SS 10A, and P - 22 - SS - 07 [1, p. 51646, Section 5.0.1, 28, pp. 80 - 82; 53, p. 10; 60, pp. 8, 9; 61, p. 7; 71 , p. 14 ; 72, pp. 55 - 61, 75, 79, 80 ]. Two additional surface soil samples, P - 21 - SS - 03 and P - 21 - SS - 04, are located within Area C [ 28, p. 80 ; 71 , p. 14 ]. Area C is located southeast of the Walton & Lonsbury Inc. property, south of West Street, along portions of residential properties adjacen t to Bliss Brook [18, pp. 20 - 21, 24; 28, pp. 32 - 33, 36, 80 - 82]. Area C encompasses surface soil sample locations within low - lying areas on residential properties, adjacent to Bliss Brook [18, pp. 20 - 21, 24]. Based on site topography , on - site observations, and flood plain data, the low - lying areas of residential properties within Area C, adjacent to Bliss Brook, are suspected to be subject to surface water flooding from Bliss Brook [18, pp. 20 - 21, 24 ; 109, pp. 1 - 2, 5 ].

- Background Concentrations: Betwee n 25 January and 1 February 2012, as part of the EPA SR and in accordance with the EPA approved January 2012 Site - Specific QAPP, background surface soil sampling activities were conducted [18, pp. 4, 15, 18 - 22; 28, pp. 18, 27 - 28, 30 - 33, 61, 71, 76 - 77, 79, 81; 31, pp. 1, 26, 28, 33 - 34, 42 ]. Ten background surface soil samples were utilized to document natural background conditions in the local vicinity of the site. One background surface soil sample (SO - 01B) was collected from an undeveloped parcel located south of the Walton & Lonsbury Inc. property, depicted on the City of Attleboro Tax Assessor's Map No. 59, as Lot No. 142 [10; 12; 18, p. 4 ; 28, pp. 18, 61; 68]. Two background surface soil samples (P - 06 - SS - 07 and P - 06 - SS - 08) were collected from a residential property located south of the Walton & Lonsbury Inc. property, which is depicted on the City of Attleboro Tax Assessor's Map No. 59, as Lot No. 220 [10; 12; 18, p. 15; 28, pp. 27 - 28, 71; 6 8]. One b ackground surface soil sample (P - 14 - SS 01) was collected from a residential property located southeast of the Walton & Lonsbury Inc. property, which is depicted on the City of Attleboro Tax Assessor's Map No. 49, as Lot No. 157D [10; 12; 18, p. 21; 28, pp. 33, 76; 69]. Two background surface soil samples (P - 16 - SS - 03 and P - 16 - SS - 04) were collected from a residential property located southeast of the Walton & Lonsbury Inc. property, which is depicted on the City of Attleboro Tax Assessor's Map No. 49, as Lot No. 157B [10; 12; 18, pp. 21 - 22; 28, pp. 33, 77; 69]. One background surface soil sample (P - 18 - SS - 04) was collected from a residential property located southeast of the Walton & Lonsbury Inc. property, which is depicted on the City ofSoil Exposure Resident Population Threat

Walton & Lonsbury Inc. 116 HRS Documentation Record MAD001197755 5 September 2012 Attleboro Tax Assesso r's Map No. 49, as Lot No. 96 [10; 12; 18, p. 18; 28, pp. 30, 79; 69]. Three background surface soil samples (P - 22 - SS - 01A, P - 22 - SS - 01B, and P - 22 - SS - 08) were collected from a residential property located southeast of the Walton & Lonsbury Inc. property, whi ch is depicted on the City of Attleboro Tax Assessor's Map No. 49, as Lot No. 126 [10; 12; 18, pp. 19 - 20; 28, pp. 31 - 32, 81; 6 9]. All background surface soil sample locations are depicted in Figure 4. The 10 background surface soil samples were collected in the vicinity of the site from the same depth interval (0 - to 2 - feet), during the same time period, and utilizing the same collection and analytical methods as the surface soil samples presented as part of the Areas A, B, and C c haracterization [18, pp. 14 - 16, 18 - 25, 27, 28; 28, pp . 18, 27 - 33, 30 - 61, 67, 69 - 73, 76 - 83; 32, pp. 12 - 16; 35, pp. 3, 5, 20, 23, 26, 30, 33 - 35, 38 - 39, 43 - 44, 46, 53, 58, 94 , 102 - 103, 110 - 111, 117, 120 - 122, 125 - 126, 129, 133 - 134, 137 - 138, 144 - 146, 148, 151, 155, 163; 50, p. 1; 53, p . 1; 60, p. 1]. The 10 background surface soil samples collected as part of the EPA SR contained varying compositions of naturally occurring native matrix materials ( i.e. , sand, silt, clay, gravel, and organic matter) [35, pp. 43 - 44, 9 4 , 102 - 103, 117, 137 - 138, 145, 163]. The 10 background surface soil samples were selected to comprise soil characteristics/compositions encountered in the surface soil samples presented as part of Areas A, B, and C. Background surface soil sample SO - 01B was d escribed as moist, yellow brown, silt, some fine sand, little clay, trace medium - to - coarse gravel, trace organics, trace medium - to - coarse sand [35, p. 163]. Background surface soil sample P - 06 - SS - 07 was described as brown - to - dark brown, fine - to coarse sand , some silt, little fine - to - medium gravel, trace organics , trace clay [35, p. 43]. Background surface soil sample P - 06 - SS - 08 was described as brown, silt and fine - to - coarse sand, little fine - to - medium gravel, trace organics, trace clay [35, p. 44]. Backgro und surface soil sample P - 14 - SS - 01 was described as dry, brown, silt , trace clay, trace fine - to - coarse sand, trace fine - to - medium gravel, trace organics [35, p. 94 ]. Background surface soil sample P - 16 - SS - 03 was described as moist, brown - to - dark brown, cla y, some silt, trace organics, trace fine gravel, trace fine - to - coarse sand [35, p. 102]. Background surface soil sample P - 16 - SS - 04 was described as wet, brown - to - dark brown, clay and silt, trace organics, trace fine to - coarse sand [35, p. 103]. Background surface soil sample P - 18 - SS - 04 was described as brown, fine - to coarse sand, little silt, little clay, trace fine - to - medium gravel, trace organics [35, p. 117]. Background surface soil sample P - 22 - SS - 01A was described as dark brown, silt, little organics, t race fine - to - coarse sand [35, p. 137]. Background surface soil sample P - 22 - SS - 01B was described as moist, dark brown, clay and silt, little fine - to - coarse sand, trace organics [35, p. 138]. Background surface soil sample P - 22 - SS 08 was described as brown, fine - to - coarse sand, some silt, trace fine - to - medium gravel, trace clay, trace organics [35, p. 145]. Table 5 3 - Background Surface Soil Sample Location Description Sample ID Sample Medium Depth Date References SO - 01B Surface Soil < 2 feet bgs 25 Jan. 2012 18, p. 4 ; 28, p. 61 P - 06 - SS - 07 Surface Soil < 2 feet bgs 31 Jan. 2012 18, p. 15; 28, p. 71 P - 06 - SS - 08 Surface Soil < 2 feet bgs 31 Jan. 2012 18, p. 15; 28, p. 71 P - 14 - SS - 01 Surface Soil < 2 feet bgs 1 Feb. 2012 18, p. 21; 28, p. 76 P - 16 - SS - 03 Surface Soil < 2 feet bgs 1 Feb. 2012 18, p. 21; 28, p. 77 P - 16 - SS - 04 Surface Soil < 2 feet bgs 1 Feb. 2012 18, p. 22; 28, p. 77Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 117 HRS Documentation Record MAD001197755 5 September 2012 Table 5 3 - Background Surface Soil Sample Location Description Sample ID Sample Medium Depth Date References P - 18 - SS - 04 Surface Soil < 2 feet bgs 1 Feb. 2012 18, p. 18; 28, p. 79 P - 22 - SS - 01A Surface Soil < 2 feet bgs 1 Feb. 2012 18, p. 19; 28, p. 81 P - 22 - SS - 01B Surface Soil < 2 feet bgs 1 Feb. 2012 18, p. 19; 28, p. 81 P - 22 - SS - 08 Surface Soil < 2 feet bgs 1 Feb. 2012 18, p. 20; 28, p. 81 Jan. = January bgs = Below ground surface Feb. = February < = Less than As presented above, the 10 background surface soil samples contained varying compositions of naturally occurring native matrix materials ( i.e. , sand, silt, cl ay, gravel, and organic matter), which constituted major and/or minor components of the sample s [35, pp. 43 - 44, 94, 102 - 103, 117, 137 - 138, 145, 163]. Similarly, the surface soil samples presented as part of the Areas A, B, and C characterization exhibited varying compositions of the same naturally occurring native matrix materials (see Contaminated Samples presented below). The analytical results of surface soil sample s presented to characterize Areas A, B, and C could be compared to the contaminant concentrations detected only in those background surface soil sample(s) which displayed the most simil ar matrix composition. However, for simplicity of the HRS documentation record, and to support the case that analytical results of surface soil samples collected from Areas A, B, and C are significantly above documented background concentrations, all 10 background surface soil samples are presented . Surface soil samples from Areas A, B, and C were compared to the highest concentrations detected among all 10 background s amples for the analytes presented. Regardless of which approach is used for the comparison of contaminant concentrations [ i.e. , comparing release surface soil samples from Areas A, B, and C to only the background surface soil sample(s) that were most simil ar in composition, or comparing release surface soil samples to the highest concentrations detect ed among all background surface soil samples] , sample analytical results for Areas A, B, and C indicate release surface soil sample contaminant concentrations significantly above background levels. Background surface soil samples SO - 01B, P - 06 - SS - 07, P - 06 - SS - 08, P - 14 - SS - 01, P - 16 - SS - 03, P - 16 - SS 04, P - 18 - SS - 04, P - 22 - SS - 01A, P - 22 - SS - 01B, and P - 22 - SS - 08 were submitted to a CLP l aboratory for chromium and lead analys is under CLP SOW ISM01.3 [18, pp. 27 - 28; 32, pp. 9, 12, 14 - 15; 50, pp. 1, 9; 60, pp. 1, 7; 61, pp. 1, 8 - 9]. COCs for all samples collected as part of the 2012 EPA SR and presented in this HRS d ocumentation r ecord are provided in Reference 32. The applicabl e COC pages for the background surface soil samples, and all corresponding sample identifiers, are provided in available COC and field notes reference documentation [18, pp. 4, 11 - 12, 15, 18 - 22, 25; 32, pp. 9, 12, 14 - 15]. In addition, all sample IDs and associated sample numbers and COC numbers are provided in a reference table [115]. The analytical data for background surface soil samples were validated on a Tier II level according to EPA Region I Tiered Organic and Inorga nic Data Validation Guidelines [ 50, pp. 1, 3; 60, pp. 1, 3; 61, pp. 1, 3 ]. I n addition, the validation was conducted independently by designated chemists who were not involved in the sample collection and HRS evaluation [ 35, pp. 43 - 44, 94, 102 - 103, 117, 13 7 - 138, 145, 163; 50, pp. 1, 3; 60, pp. 1, 3; 61, pp. 1, 3 ]. As part of this HRS documentation record and the evaluation of background concentrations, the following hazardous substances in background surface soil samples are presented: chromium and lead.Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 118 HRS Documentation Record MAD001197755 5 September 2012 A mong the 10 background surface soi l samples , chromium was detected at a maximum concentration of 14.1 mg/Kg in sample P - 14 - SS - 01; and lead was detected at a maximum concentration of 76.4 mg/Kg in sample P - 22 - SS - 01A [18, pp. 4, 11 - 12, 15, 18 - 22, 25, 27 - 28; 28, pp. 61, 71, 76, 77, 79, 81; 50, p. 9; 60, p. 7; 61, pp. 8, 9; 72, pp. 2 3 - 32 , 72, 74, 81, 82, 84]. O bserved contamination is established for Areas A, B, and C when analytical results of samples collected from these areas indicate concentrations at least three times greater than the highest background concentrations detected among the 10 background surface soil samples [1, pp. 51588, Section 2.2.3, 51589, Table 2 - 3, 51646, Section 5.0.1]. Ta ble 5 4 – Hazardous Substances Associated with Background Surface Soil Samples Sample ID Hazardous Substance Hazardous Substance Concentration Sample - Adjusted CRQL Reference SO - 01B Chromium 10.7 mg/Kg 0.87 mg/Kg 18, pp. 4, 11 - 12 ; 28, p. 61; 50, p. 9; 72, pp. 1, 32, 72 Lead 10.1 mg/Kg 0.87 mg/Kg P - 06 - SS - 07 Chromium 12.5 mg/Kg 0.98 mg/Kg 18, pp. 15, 27 - 28; 28, p. 71; 60, p. 7; 72, pp. 1, 23, 74 Lead 23.4 mg/Kg 0.98 mg/Kg P - 06 - SS - 08 Chromium 10.3 mg/Kg 1.05 mg/Kg 18, pp. 15, 27 - 28; 28, p. 71; 60, p. 7; 72, pp. 1, 24, 74 Lead 31.4 mg/Kg 1.05 mg/Kg P - 14 - SS - 01 Chromium 14.1 mg/Kg 1.41 mg/Kg 18, pp. 21, 27 - 28; 28, p. 76; 61, p. 8; 72, pp. 1, 25, 81 Lead 30.4 mg/Kg 1.41 mg/Kg P - 16 - SS - 03 Chromium 12.0 mg/Kg 1.60 mg/Kg 18, pp. 21, 27 - 28; 28, p. 77; 61, p. 9; 72, pp. 1, 26, 81 Lead 59.9 mg/Kg 1.60 mg/Kg P - 16 - SS - 04 Chromium 13.3 mg/Kg 1.34 mg/Kg 18, pp. 22, 27 - 28; 28, p. 77; 61, p. 9; 72, pp. 1, 27, 81 Lead 66.8 mg/Kg 1.34 mg/Kg P - 18 - SS - 04 Chromium 11.0 mg/Kg 1.12 mg/Kg 18, pp. 18, 27 - 28; 28, p. 79; 61, p. 9; 72, pp. 1, 28, 81 Lead 29.4 mg/Kg 1.12 mg/Kg P - 22 - SS - 01A Chromium 10.4 mg/Kg 1.67 mg/Kg 18, pp. 19, 27 - 28; 28, p. 81; 61, p. 9; 72, pp. 1, 81, 84 Lead 76.4 mg/Kg 1.67 mg/Kg P - 22 - SS - 01B Chromium 9.7 mg/Kg 1.44 mg/Kg 18, pp. 19, 27 - 28; 28, p. 81; 61, p. 9; 72, pp. 1, 30, 82 Lead 38.9 mg/Kg 1.44 mg/Kg P - 22 - SS - 08 Chromium 10.0 mg/Kg 1.15 mg/Kg 18, pp. 20, 27 - 28; 28, p. 81; 61, p. 9; 72, pp. 1, 31, 82 Lead 51.5 mg/Kg 1.15 mg/Kg CRQL = Contract Required Quantitation Limit mg/Kg = Milligrams per K ilogramSoil Exposure Resident Population Threat

Walton & Lonsbury Inc. 119 HRS Documentation Record MAD001197755 5 September 2012 - Contaminated Samples For the sample descriptions presented below, a ll property designations ( e.g. , “P - 01”, “P - 02”, etc. ) were assigned during the 2012 EPA SR , and are associated with the corresponding identifiers for soil samples collected from each property ( e.g. , P - 01 - SS - ##, P - 02 - SS - ##, etc. ) [18, pp. 13 - 14]. Area A: Between 31 January and 2 February 2012, as part of the EPA SR and in accordance with the EPA approved January 2012 Site - Specific QAPP, surface soil sampling activities were conducted for Area A [18, pp. 14 - 16, 18 - 23, 25, 27 - 28; 28, pp. 27 - 29, 35, 67, 69 - 73 , 83 ; 31, pp. 1, 26, 28, 33 - 34, 42 ]. As part of the Area A characterization, 10 surface soil samples were collected from residential properties located south of the Walton & Lonsbury Inc. property (samples P - 01 - SS - 02B, P - 01 - SS - 03B, P - 04 - SS - 03, P - 04 - SS - 06, P - 06 - SS - 02, P - 06 - SS - 03, P - 07 - SS - 02, P - 09 - SS - 02, P - 09 - SS - 07, and P - 30 - SS - 02) [18, pp. 14 - 16, 23, 27 - 28; 28, pp. 27 - 29, 35, 67, 69 - 73 , 83 ]. Surface soil samples utilized to characterize Area A include the following: two surface soil samples (P - 01 - SS - 02B and P - 01 - SS - 03B) collected from a proper ty designated as “P - 01”, depicted on the City of Attleboro Tax Assessor's Map No. 59, as Lot No. 190A; two surface soil samples (P - 04 - SS - 03 and P - 04 - SS - 06) collected from a property designated as “P - 04”, depicted on the City of Attleboro Tax Assessor's Map No. 59, as Lot No. 225; two surface soil samples (P - 06 - SS - 02 and P - 06 - SS - 03) collected from a property designated as “P - 06”, depicted on the City of Attleboro Tax Assessor's Map No. 59, as Lot No. 220; two surface soil samples (P - 07 - SS - 02, and field dupli cate P - 30 - SS - 02) collected from a property designated as “P - 07”, depicted on the City of Attleboro Tax Assessor's Map No. 49, as Lot No. 113; and two surface soil samples (P - 09 - SS - 02 and P - 09 - SS - 07) collected from a property designated as “P - 09”, depicted on the City of Attleboro Tax Assessor's Map No. 49, as Lot No. 114B [12; 18, pp. 13 - 14; 68; 69]. All surface soil samples collected from Area A were collected from depths less than 2 feet bgs [35, pp. 3, 5, 23, 26, 38 - 39, 46, 53, 58]. Locations of all sur face soil samples collected from Area A are depicted in Figures 12 and 13 . Each surface soil sample collected within Area A and presented in this HRS documentation record was collected from a residential property; furthermore, each Area A surface soil sam ple location was withi n 200 feet of the corresponding residential property’s building structure ( see Figures 12 and 13 ) [18, p. 14; 92 , pp. 1 - 4 ]. Surface soil samples collected from Area A were of similar composition to the native materials described in the background surface soil samples presented for Areas A, B, and C. Surface soil sample P - 01 - SS - 02B was described as saturated, dark brown - to - black , silt, little clay, trace fine - to - coarse sand, trace organics [35, p. 3]. Surface soil sample P - 01 - SS - 03B was described as moist, dark brown, silt and clay, trace fine to - coarse sand, little organics [35, p. 5]. Surface soil sample P - 04 - SS - 03 was describe d as saturated, dark brown, silt, some fine - to - coarse sand, little clay, trace fine - to - medium gravel [35, p. 23]. Surface soil sample P - 04 - SS - 06 was described as saturated, silt, some fine - to - coarse sand, trace fine gravel, trace organics, trace clay [35, p. 26]. Surface soil sample P - 06 - SS - 02 was described as moist, dark brown, fine to - coarse sand and silt, trace organics, trace clay, trace fine gravel [35, p. 38]. Surface soil sample P - 06 - SS - 03 was described as wet, dark brown - to - black, silt and fine - to - c oarse sand, trace fine - to - medium gravel, trace organics, trace clay [35, p. 39]. Surface soil sample P - 07 - SS - 02 and field duplicate P - 30 - SS 02 were described as brown, fine - to - coarse sand and silt, little fine - to - medium gravel, trace organics, trace clay [ 35, p. 46]. Surface soil sample P - 09 - SS - 02 was described as brown, fine - to - coarse sand, little silt, trace fine - to medium gravel, trace clay, trace organics [35, p. 53]. Surface soil sample P - 09 - SS - 07 was described as brown, silt, some fine - to - coarse sand , trace organics, trace fine gravel [35, p. 58].Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 120 HRS Documentation Record MAD001197755 5 September 2012 Area B: On 1 and 2 February 2012, as part of the EPA SR and in accordance with the EPA - approved January 2012 Site - Specific QAPP, surface soil sampling activities were conducted for Area B [18, pp. 18 - 19 , 21 - 25, 27 - 28; 28, pp. 30 - 31, 33 - 36, 69 - 70, 78 - 80, 83; 31, pp. 1, 26, 28, 33 - 34, 42 ]. As part of the Area B characterization, 14 surface soil samples were collected from residential properties located southeast of the Walton & Lonsbury Inc. property (samples P - 03 - SS - 05, P - 05 - SS - 01, P - 05 - SS - 04, P - 05 - SS - 05, P - 05 - SS - 06, P - 17 - SS - 07A, P - 17 - SS - 07B, P - 18 - SS - 07, P - 18 - SS - 08, P - 18 - SS - 09, P - 19 - SS - 03, P - 20 - SS - 01, P 20 - SS - 04A, and P - 31 - SS - 04A) [18, pp. 22, 27 - 28; 28, pp. 30 - 31, 33 - 36, 69 - 70, 78 - 80, 83]. Surface so il samples utilized to characterize Area B include the following: one surface soil sample (P - 03 - SS - 05) collected from a property designated as “P - 03”, depicted on the City of Attleboro Tax Assessor's Map No. 49, as Lot No. 112; three surface soil samples ( P - 05 - SS - 01, P - 05 - SS - 04, and P - 05 - SS - 05) collected from a property designated as “P - 05”, depicted on the City of Attleboro Tax Assessor's Map No. 49, as Lot No. 109; one surface soil sample (P - 05 - SS - 06) collected from a property designated as “P - 05”, depict ed on the City of Attleboro Tax Assessor's Map No. 49, as Lot No. 110; two surface soil samples (P - 17 - SS - 07A and P - 17 - SS - 07B) collected from a property designated as “P - 17”, depicted on the City of Attleboro Tax Assessor's Map No. 49, as Lot No. 94; three surface soil samples (P - 18 - SS - 07, P - 18 - SS - 08, and P - 18 - SS 09) collected from a property designated as “P - 18”, depicted on the City of Attleboro Tax Assessor's Map No. 49, as Lot No. 96; one sample (P - 19 - SS - 03) collected from a property designated as “P - 19” , depicted on the City of Attleboro Tax Assessor's Map No. 49, as Lot No. 97A; and three surface soil samples [P 20 - SS - 01 and P - 20 - SS - 04A/ P - 31 - SS - 04A (field duplicate)] collected from a property designated as “P 20”, depicted on the City of Attleboro Tax Assessor's Map No. 49, as Lot No. 97 [28, pp. 30 - 31, 33 - 36, 69 - 70, 78 - 80, 83; 68; 69]. Surface soil samples P - 17 - SS - 07A and P - 17 - SS - 07B represent separate depth intervals at the same location; otherwise, all sample s listed above (excluding field duplicates ) represent discrete sample locations [18, p p . 19, 23 ; 28, pp. 30 - 31, 33 - 36, 69 - 70, 78 - 80, 83]. All surface soil samples collected from the Area B were collected from depths less than 2 feet bgs [35, pp. 20, 30, 33 - 35, 110 - 111, 120 - 122, 125 - 126, 129]. Loca tions of all surface soil samples collected from Area B are depicted in Figures 14, 15 and 16. Each surface soil sample collected within Area B and presented in this HRS documentation record was collected from a residential property; furthermore, each Area B surface soil sample location was within 200 feet of the corresponding residential property’s building structure ( see Figures 14, 15 and 16 ) [18, p. 14; 92 , pp. 1 - 2, 5 - 7 ]. Surface soil samples collected from Area B were of similar composition to t he native materials described in the background surface soil samples presented for Areas A, B, and C. Surface soil sample P - 03 - SS - 05 was described as wet, yellow brown - to - brown, fine - to - coarse sand, trace clay, trace silt, trace fine gravel, trace organics [35, p. 20]. Surface soil sample P - 05 - SS - 01 was described as saturated, dark brown, clay and silt, trace fine - to - coarse sand, trace organics, trace fine - to - medium gravel [35, p. 30]. Surface soil sample P - 05 - SS - 04 was described as wet, dark brown, silt and fine - to - coarse sand, little clay, trace organics, trace fine gravel [35, p. 33]. Surface soil sample P - 05 - SS - 05 was described as dry, dark brown, silt, some fine - to - coarse sand, trace organi cs, trace fine - to - medium gravel, trace debris (plastic wrapper, paper) [35, p. 34]. Surface soil sample P - 05 - SS - 06 was described as dry, dark brown, silt, little fine - to coarse sand, little organics, trace clay [35, p. 35]. Surface soil sample P - 17 - SS - 07A was described as moist, dark brown, silt and clay, trace fine - to - coarse sand, trace fine gravel, trace organics [35, p. 110]. Surface soil sample P - 17 - SS - 07B was described as saturated, dark brown, silt and clay, little fine - to coarse sand, trace organics [35, p. 111]. Surface soil sample P - 18 - SS - 07 was described as wet, dark brown, silt and clay, little organics, trace fine - to - coarse sand, trace fine - to - medium gravel [35, p. 120]. Surface soil sample P - 18 - SS - 08 was described as moist, dark brown, silt and clay, trace fine - to - coarse sand, trace organics, trace fine gravel [35, p. 121]. Surface soil sample P - 18 - SS - 09 was described as saturated, dark brown, silt and clay, trace fine - to - coarse sand, trace organics, trace fine gravel [35, p.Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 121 HRS Documentation Record MAD001197755 5 September 2012 122]. Surface soil s ample P - 19 - SS - 03 was described as dry, dark brown, silt, little clay, trace fine - to coarse sand, trace organics, trace fine gravel [35, p. 125]. Surface soil sample P - 20 - SS - 01 was described as brown, fine - to - coarse sand, little silt, trace fine - to - medium g ravel, trace clay, trace organics [35, p. 126]. Surface soil samples P - 20 - SS - 04A and field duplicate P - 31 - SS - 04A were described as brown - to dark brown, silt, trace fine - to - coarse sand, trace organics, trace fine gravel, trace debris (cinder ash) [35, p. 12 9]. Area C: On 1 and 2 February 2012, as part of the EPA SR and in accordance with the EPA - approved January 2012 Site - Specific QAPP, surface soil sampling activities were conducted for Area C [18, pp. 20 - 21, 24, 27 - 28; 28, pp. 32 - 33, 36, 80 - 82; 31, pp. 1, 26, 28, 33 - 34, 42 ]. As part of the Area C characterization, seven surface soil samples (P - 21 - SS - 03, P - 21 - SS - 04, P - 22 - SS - 07, P - 22 - SS - 09A, P - 22 - SS - 10A, P - 23 - SS 02, and P - 23 - SS - 06) were collected from residential properties located southeast of the Walton & Lonsbury Inc. property [18, pp. 20 - 21, 24, 27 - 28; 28, pp. 32 - 33, 36, 80 - 82]. Surface soil sampl es utilized to characterize Area C include the following: two surface soil samples (P - 21 - SS - 03 and P - 21 - SS - 04) collected from a property designated as “P - 21”, depicted on the City of Attleboro Tax Assessor's Map No. 49, as Lot No. 125; three surface soil samples (P - 22 - SS - 07, P - 22 - SS - 09A, and P - 22 - SS - 10A) collected from a property designated as “P - 22”, depicted on the City of Attleboro Tax Assessor's Map No. 49, as Lot No. 126; and two surface soil samples (P - 23 - SS - 02 and P - 23 - SS - 06) collected from a property designated as “P - 23”, depicted on the City of Attleboro Tax Assessor's Map No. 49 , as Lot No. 124 [28, pp. 80 - 82; 69]. All surface soil samples collected fro m the Area C were collected from depths less than 2 feet bgs [35, pp. 133 - 134, 144, 146, 148, 151, 155]. Locations of all surface soil samples collected from Area C are depicted in Figure 1 7 . Each surface soil sample collected within Area C and presented in this HRS documentation record was collected from a residential property; furthermore, each Area C surface soil sample location was within 200 feet of the corresponding residential property’s building structure (Figure 17) [18, p. 14; 92 , pp. 1 - 2, 8 ]. Surface soil samples collected from Area C were of similar composition to the native materials described in the background samples presented for Areas A, B, and C. Surface soil sample P - 21 - SS - 03 was described as moist, brown, clay and silt, little fine - t o - coarse sand, trace organics, trace fine gravel [35, p. 133]. Surface soil sample P - 21 - SS - 04 was described as moist, dark brown, clay, some silt, little fine sand, trace medium - to - coarse sand, trace fine gravel, trace organics [35, p. 134]. Surface soil s ample P - 22 - SS 07 was described as wet, dark brown, silt and clay, little fine - to - coarse sand, little organics [35, p. 144]. Surface soil sample P - 22 - SS - 09A was described as saturated, dark brown, silt, little clay, trace fine - to coarse sand, trace organics , trace fine gravel [35, p. 146]. Surface soil sample P - 22 - SS - 10A was described as saturated, dark brown, clay and silt, trace fine - to - coarse sand, trace organics [35, p. 148]. Surface soil sample P - 23 - SS - 02 was described as wet, dark brown, clay and silt, little fine - to - coarse sand, trace fine gravel, trace organics [35, p. 151]. Surface soil sample P - 23 - SS - 06 was described as brown - to - dark brown, silt, some fine - to - coarse sand, trace organics, trace fine gravel, trace clay [35, p. 155]. Table 5 5 - Surfac e Soil Sample Location Descriptions for Areas A, B, and C Area Sample ID Sample Medium Depth Date References

A P - 01 - SS - 02B Surface Soil < 2 feet bgs 2 Feb. 2012 18, p. 23; 28, p. 67 A P - 01 - SS - 03B Surface Soil < 2 feet bgs 2 Feb. 2012 18, p. 23; 28, p. 67Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 122 HRS Documentation Record MAD001197755 5 September 2012 Table 5 5 - Surfac e Soil Sample Location Descriptions for Areas A, B, and C Area Sample ID Sample Medium Depth Date References

A P - 04 - SS - 03 Surface Soil < 2 feet bgs 31 Jan. 2012 18, p. 15; 28, p. 69 A P - 04 - SS - 06 Surface Soil < 2 feet bgs 31 Jan. 2012 18, p. 15; 28, p. 70 A P - 06 - SS - 02 Surface Soil < 2 feet bgs 31 Jan. 2012 18, p. 14; 28, p. 71 A P - 06 - SS - 03 Surface Soil < 2 feet bgs 31 Jan. 2012 18, p. 14 ; 28, p. 71 A P - 07 - SS - 02 Surface Soil < 2 feet bgs 31 Jan. 2012 18, p. 15; 28, p. 7 2 A P - 09 - SS - 02 Surface Soil < 2 feet bgs 31 Jan. 2012 18, p. 16; 28, p. 72 A P - 09 - SS - 07 Surface Soil < 2 feet bgs 31 Jan. 2012 18, p. 16; 28, p. 73 A P - 30 - SS - 02 Surface Soil < 2 feet bgs 31 Jan. 2012 18, p. 15; 28, p. 83 B P - 03 - SS - 05 Surface Soil < 2 feet bgs 1 Feb. 2012 18, p. 21; 28, p. 69 B P - 05 - SS - 01 Surface Soil < 2 feet bgs 1 Feb. 2012 18, p. 22; 28, p. 70 B P - 05 - SS - 04 Surface Soil < 2 feet bgs 1 Feb. 2012 18, p. 22; 28, p.70 B P - 05 - SS - 05 Surface Soil < 2 feet bgs 1 Feb. 2012 18, p. 22; 28, p. 70 B P - 05 - SS - 06 Surface Soil < 2 feet bgs 1 Feb. 2012 18, p. 22; 28, p. 70 B P - 17 - SS - 07A Surface Soil < 2 feet bgs 2 Feb. 2012 18, p. 23; 28, p. 78 B P - 17 - SS - 07B Surface Soil < 2 feet bgs 2 Feb. 2012 18, p. 23; 28, p. 78 B P - 18 - SS - 07 Surface Soil < 2 feet bgs 1 Feb. 2012 18, p. 18; 28, p. 79 B P - 18 - SS - 08 Surface Soil < 2 feet bgs 2 Feb. 2012 18, p. 25; 28, p. 79 B P - 18 - SS - 09 Surface Soil < 2 feet bgs 2 Feb. 2012 18, p. 25; 28, p. 79 B P - 19 - SS - 03 Surface Soil < 2 feet bgs 1 Feb. 2012 18, p. 19; 28, p. 79 B P - 20 - SS - 01 Surface Soil < 2 feet bgs 1 Feb. 2012 18, p. 18; 28, p. 80 B P - 20 - SS - 04A Surface Soil < 2 feet bgs 2 Feb. 2012 18, p. 24; 28, p. 80 B P - 31 - SS - 04A Surface Soil < 2 feet bgs 2 Feb. 2012 18, p. 24; 28, p. 83 C P - 21 - SS - 03 Surface Soil < 2 feet bgs 1 Feb. 2012 18, p. 20; 28, p. 80 C P - 21 - SS - 04 Surface Soil < 2 feet bgs 1 Feb. 2012 18, p. 20; 28, p. 80 C P - 22 - SS - 07 Surface Soil < 2 feet bgs 1 Feb. 2012 18, p. 20; 28, p. 81 C P - 22 - SS - 09A Surface Soil < 2 feet bgs 2 Feb. 2012 18, p. 24; 28, p. 82Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 123 HRS Documentation Record MAD001197755 5 September 2012 Table 5 5 - Surfac e Soil Sample Location Descriptions for Areas A, B, and C Area Sample ID Sample Medium Depth Date References

C P - 22 - SS - 10A Surface Soil < 2 feet bgs 2 Feb. 2012 18, p. 24; 28, p. 82 C P - 23 - SS - 02 Surface Soil < 2 feet bgs 1 Feb. 2012 18, p. 21; 28, p. 82 C P - 23 - SS - 06 Surface Soil < 2 feet bgs 1 Feb. 2012 18, p. 21; 28, p. 82 Jan. = January bgs = Below ground surface Feb. = February < = Less than Area A: The 10 surface soil samples collected from Area A (P - 01 - SS - 02B, P - 01 - SS - 03B, P - 04 - SS - 03, P - 04 - SS 06, P - 06 - SS - 02, P - 06 - SS - 03, P - 07 - SS - 02, P - 09 - SS - 02, P - 09 - SS - 07, and P - 30 - SS - 02) were submitted to a CLP l aboratory for chromium and lead analysis under CLP SOW ISM01.3 [18, pp. 27 - 28; 32, pp. 12, 16; 53, pp. 1, 9; 60, pp. 1, 7 - 8]. COCs for all samples collected as part of the 2012 EPA SR and presented in this HRS d ocumentation r ecord are provided in Reference 32. T he applicable COC pages for Area A samples, and all corresponding sample identifiers, are provide d in available COC and field notes reference documentation [18, pp. 14 - 16, 23; 32, pp. 12, 16]. In addition, all sample IDs and associated sample numbers and COC numbers are provided in a reference table [115]. The analytical data for Area A surface soil s amples were validated on a Tier II level according to EPA Region I Tiered Organic and Inorganic Data Validation Guidelines [ 53, pp. 1, 4; 60, pp. 1, 3 ]. I n addition, the validation was conducted independently by designated chemists who were not involved in the sample collection and HRS evaluation [35, pp. 3, 5, 23, 26, 38 - 39, 46, 53, 58; 53, pp. 1, 4; 60, pp. 1, 3]. Among the 10 surface soil samples collected from Area A , chromium was detected at a maximum concentration of 617 mg/Kg in surface soil sample P - 07 - SS - 02, and lead was detected at a maximum concentration of 530 mg/Kg in surface soil sample P - 04 - SS - 06 [18, pp. 14 - 16, 23, 27 - 28; 28, pp. 67, 69

– 73, 83; 53, p. 9; 60, pp. 7, 8; 72, pp. 33, 34, 36, 37, 42 - 46, 64, 74, 75, 78, 79 ]. Based on chemical analysis of samples collected as part of the EPA SR , Area A has been documented to contain chromium and lead at concentrations significantly above background concentrations [18, pp. 14 - 16, 23, 27 - 28; 28, pp. 67, 69

– 73, 83; 53, p. 9; 60, pp. 7, 8; 72, pp . 33, 34, 36, 37, 42 - 46, 64, 74, 75, 78, 79]. Area B: The 14 surface soil samples collected from Area B (P - 03 - SS - 05, P - 05 - SS - 01, P - 05 - SS - 04, P - 05 - SS - 05, P 05 - SS - 06, P - 17 - SS - 07A, P - 17 - SS - 07B, P - 18 - SS - 07, P - 18 - SS - 08, P - 18 - SS - 09, P - 19 - SS - 03, P - 20 - SS - 01, P - 20 - SS - 04A, and P - 31 - S S - 04A) were submitted to a CLP l aboratory for chromium and lead analysis under CLP SOW ISM01.3 [18, pp. 27 - 28; 32, pp. 13 - 14, 16; 53, pp. 1, 9 - 10; 60, pp. 1, 9; 61, pp. 1, 7 - 8]. COCs for all samples collected as part of the 2012 EPA S R and presented in this HRS d ocumentation r ecord are provided in Reference 32. The applicable COC pages for the Area B surface soil samples, and all corresponding sample identifiers, are provided in available COC and field notes reference documentation [18 , pp. 18 - 19, 21 - 25; 32, pp. 13 - 14, 16]. In addition, all sample IDs and associated sample numbers and COC numbers are provided in a reference table [115]. The analytical data for Area B surface soil samples were validated on a Tier II level according to EPA Region I Tiered Organic and Inorganic Data Validation Guidelines [ 53, pp. 1, 4; 60, pp. 1, 3; 61, pp. 1, 3 ]. I n addition, the validation was conducted independently by designated chemists who were not involved in the sample collection and HRS evaluatio n [35, pp. 20, 30, 33 - 35, 110 - 111, 120 - 122, 125 - 126, 129; 53, pp. 1, 4; 60, pp. 1, 3; 61, pp.Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 124 HRS Documentation Record MAD001197755 5 September 2012 1, 3]. Among the 14 surface soil samples collected from Area B , chromium was detected at a maximum concentration of 2,020 mg/Kg in surface soil sample P - 18 - SS - 07, and lead was detected at a maximum concentration of 359 mg/Kg in surface soil sample P - 19 - SS - 03 [18, pp. 18 - 19, 21 - 25, 27 - 28; 28, pp. 69, 70, 78 - 80, 83; 53, pp. 9, 10; 60, p. 9; 61, pp. 7, 8; 72, pp. 35, 38 - 41, 47 - 54, 64, 76, 78 - 81 ]. Based on che mical analysis of samples collected as part of the EPA SR , Area B has been documented to contain chromium and lead at concentrations significantly above background concentrations [18, pp. 18 - 19, 21 - 25, 27 - 28; 28, pp. 69, 70, 78 - 80, 83; 53, pp. 9, 10; 60, p. 9; 61, pp. 7, 8; 72, pp. 35, 38 - 41, 47 - 54, 64, 76, 78 - 81]. Area C: The seven surface soil samples collected from Area C (P - 21 - SS - 03, P - 21 - SS - 04, P - 22 - SS - 07, P - 22 - SS 09A, P - 22 - SS - 10A, P - 23 - SS - 02, and P - 23 - SS - 06) were submitted to a CLP l aborator y for chromium and lead analysis under CLP SOW ISM01.3 [18, pp. 27 - 28; 32, pp. 12 - 13, 16 ; 53, pp. 1, 10; 60, pp. 1, 8 - 9; 61, pp. 1, 7]. COCs for all samples collected as part of the 2012 EPA SR and presented in this HRS d ocumentation r ecord are provided in Reference 32. The applicable COC pages for the Area C surface soil samples, and all corresponding sample identifiers, are provided in available COC and field notes reference documentation [18, pp. 20 - 21, 24; 32, pp. 12 - 13, 16]. In addition, all sample IDs and associated sample numbers and COC numbers are provided in a reference table [115]. The analytical data for Area C surface soil samples were validated on a Tier II level according to EPA Region I Tiered Organic and Inorganic Data Validation Guidelines [ 53, pp. 1, 4; 60, pp. 1, 3, 61, pp. 1, 3 ]. I n addition, the validation was conducted independently by designated chemists who were not involved in the sample collection and HRS evaluation [35, pp. 133, 134, 144, 146, 148, 151, 1 55; 53, pp. 1, 4; 60, pp. 1, 3, 61, pp. 1, 3]. Among the seven surface soil samples collected from Area C , chromium was detected at a maximum concentration of 1,180 mg/Kg in surface soil sample P - 23 - SS - 02, and lead was detected at a maximum concentration o f 554 mg/Kg in surface soil sample P - 22 - SS - 10A [18, pp. 20 - 21, 24, 27 - 28; 28, pp. 80 - 82; 53, p. 10; 60, pp. 8, 9; 61, p. 7; 72, pp. 55 - 61, 75, 79, 80 ]. Based on chemical analysis of samples collected as part of the EPA SR , Area C has been documented to co ntain chromium and lead at concentrations significantly above background concentrations [18, pp. 20 - 21, 24, 27 - 28; 28, pp. 80 - 82; 53, p. 10; 60, pp. 8, 9; 61, p. 7; 72, pp. 55 - 61, 75, 79, 80]. Area Letters: A, B, and C Table 5 6 – Hazardous Substances Associated with Areas A, B, and C Area Sample ID Hazardous Substance Hazardous Substance Concentration Sample Adjusted

CRQL Reference Area A: A P - 01 - SS - 02B Chromium 119 mg/Kg 1.71 mg/Kg 18, pp. 23, 27 - 28; 28, p. 67; 53, p. 9; 72, pp. 1, 33, 78 A P - 01 - SS - 03B Chromium 67.7 mg/Kg 1.69 mg/Kg 18, pp. 23, 27 - 28; 28, p. 67 ; 53, p. 9; 72, pp. 1, 34, 78 A P - 04 - SS - 03 Chromium 112 mg/Kg 1.62 mg/Kg 18, pp. 15, 27 - 28; 28, p. 69 ; 60, p. 7; 72, pp. 1, 36, 74 Lead 338 mg/Kg 1.62 mg/KgSoil Exposure Resident Population Threat

Walton & Lonsbury Inc. 125 HRS Documentation Record MAD001197755 5 September 2012 Table 5 6 – Hazardous Substances Associated with Areas A, B, and C Area Sample ID Hazardous Substance Hazardous Substance Concentration Sample Adjusted

CRQL Reference A P - 04 - SS - 06 Chromium 253 mg/Kg 1.45 mg/Kg 18, pp. 15, 27 - 28; 28, p. 70 ; 60, p. 7; 72, pp. 1, 37, 74 Lead 530 mg/Kg 1.45 mg/Kg A P - 06 - SS - 02 Chromium 147 mg/Kg 1.39 mg/Kg 18, pp. 14, 27 - 28; 28, p. 71; 60, p. 7; 72, pp. 1, 42, 74 A P - 06 - SS - 03 Chromium 187 mg/Kg 1.18 mg/Kg 18, pp. 14 , 27 - 28; 28, p. 71 ; 60, p. 7; 72, pp. 1, 43, 74 A P - 07 - SS - 02 Chromium 617 mg/Kg 0.87 mg/Kg 18, pp. 15, 27 - 28; 28, p. 7 2 ; 60, p. 7; 72, pp. 1, 44, 74 A P - 09 - SS - 02 Chromium 171 mg/Kg 0.77 mg/Kg 18, pp. 16, 27 - 28; 28, p. 72; 60, p. 8; 72, pp. 1, 45, 75 Lead 235 mg/Kg 0.77 mg/Kg A P - 09 - SS - 07 Chromium 569 mg/Kg 1.08 mg/Kg 18, pp. 16, 27 - 28; 28, p. 73; 60, p. 8; 72, pp. 1, 46, 75 A P - 30 - SS - 02 Chromium 536 mg/Kg 0.82 mg/Kg 18, pp. 15, 27 - 28; 28, p. 83; 60, p. 8; 72, pp. 1, 6 3 , 7 5 Area B: B P - 03 - SS - 05 Chromium 55.6 mg/Kg 1.06 mg/Kg 18, pp. 21, 27 - 28; 28, p. 69; 60, p. 9; 72, pp. 1, 35, 76 B P - 05 - SS - 01 Chromium 261 mg/Kg 1.41 mg/Kg 18, pp. 22, 27 - 28; 28, p. 70 ; 61, p. 7; 72, pp. 1, 38, 80 B P - 05 - SS - 04 Chromium 258 mg/Kg 1.18 mg/Kg 18, pp. 22, 27 - 28; 28, p.70; 61, p. 7; 72, pp. 1, 39, 80 B P - 05 - SS - 05 Chromium 104 mg/Kg 1.07 mg/Kg 18, pp. 22, 27 - 28; 28, p. 70; 61, p. 7; 72, pp. 1, 40, 80 B P - 05 - SS - 06 Chromium 234 mg/Kg 1.28 mg/Kg 18, pp. 22, 27 - 28; 28, p. 70; 61, p. 7; 72, pp. 1, 41, 80 B P - 17 - SS - 07A Chromium 857 mg/Kg 2.08 mg/Kg 18, pp. 23, 27 - 28; 28, p. 78; 53, p. 9; 72, pp. 1, 47, 78Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 126 HRS Documentation Record MAD001197755 5 September 2012 Table 5 6 – Hazardous Substances Associated with Areas A, B, and C Area Sample ID Hazardous Substance Hazardous Substance Concentration Sample Adjusted

CRQL Reference B P - 17 - SS - 07B Chromium 72.2 mg/Kg 1.26 mg/Kg 18, pp. 23, 27 - 28; 28, p. 78; 53, p. 9; 72, pp. 1, 48, 78 B P - 18 - SS - 07 Chromium 2,020 mg/Kg 2.01 mg/Kg 18, pp. 18, 27 - 28; 28, p. 79; 61, p. 8; 72, pp. 1, 49, 81 B P - 18 - SS - 08 Chromium 1,000 mg/Kg 1.74 mg/Kg 18, pp. 25, 27 - 28; 28, p. 79 ; 53, p. 9; 72, pp. 1, 50, 78 B P - 18 - SS - 09 Chromium 270 mg/Kg 1.18 mg/Kg 18, pp. 25, 27 - 28; 28, p. 79; 53, p. 9; 72, pp. 1, 51, 78 B P - 19 - SS - 03 Chromium 45.0 mg/Kg 1.44 mg/Kg 18, pp. 19, 27 - 28; 28, p. 79; 61, p. 7; 72, pp. 1, 52, 80 Lead 359 mg/Kg 1.44 mg/Kg B P - 20 - SS - 01 Lead 326 mg/Kg 1.46 mg/Kg 18, pp. 18, 27 - 28; 28, p. 80; 61, p. 7; 72, pp. 1, 53, 80 B P - 20 - SS - 04A Chromium 64.5 mg/Kg 1.49 mg/Kg 18, pp. 24, 27 - 28; 28, p. 80; 53, p. 10; 72, pp. 1, 54, 78 Lead 311 mg/Kg 1.49 mg/Kg B P - 31 - SS - 04A Chromium 67.8 mg/Kg 1.60 mg/Kg 18, pp. 24, 27 - 28; 28, p. 83; 53, p. 10; 72, pp. 1, 64, 79 Lead 304 mg/Kg 1.60 mg/Kg Area C: C P - 21 - SS - 03 Chromium 327 mg/Kg 1.35 mg/Kg 18, p. 20, 27 - 28; 28, p. 80; 60, p. 8; 72, pp. 1, 55, 75 Lead 300 mg/Kg 1.35 mg/Kg C P - 21 - SS - 04 Chromium 799 mg/Kg 1.37 mg/Kg 18, pp. 20, 27 - 28; 28, p. 80; 60, p. 8; 72, pp. 1, 56, 75 Lead 236 mg/Kg 1.37 mg/Kg C P - 22 - SS - 07 Chromium 271 mg/Kg 2.19 mg/Kg 18, pp. 20, 27 - 28; 28, p. 81; 61, p. 7; 72, pp. 1, 57, 80 Lead 267 mg/Kg 2.19 mg/Kg C P - 22 - SS - 09A Chromium 135 mg/Kg 1.45 mg/Kg 18, pp. 24, 27 - 28; 28, p. 82; 53, p. 10; 72, pp. 1, 58, 79Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 127 HRS Documentation Record MAD001197755 5 September 2012 Table 5 6 – Hazardous Substances Associated with Areas A, B, and C Area Sample ID Hazardous Substance Hazardous Substance Concentration Sample Adjusted

CRQL Reference C P - 22 - SS - 10A Chromium 153 mg/Kg 1.63 mg/Kg 18, pp. 24, 27 - 28; 28, p. 82; 53, p. 10; 72, pp. 1, 59, 79 Lead 554 mg/Kg 1.63 mg/Kg C P - 23 - SS - 02 Chromium 1,180 mg/Kg 1.14 mg/Kg 18, pp. 21, 27 - 28; 28, p. 82 ; 60, p. 9; 72, pp. 1, 60, 75 Lead 330 mg/Kg 1.14 mg/Kg C P - 23 - SS - 06 Chromium 833 mg/Kg 0.97 mg/Kg 18, pp. 21, 27 - 28; 28, p. 82; 60, p. 9; 72, pp. 1, 61, 75 Lead 232 mg/Kg 0.97 mg/Kg CRQL = Contract Required Quantitation Limit mg/Kg = Milligrams per Kilogram Attribution The operational history of the Walton & Lonsbury Inc. property as a chromium electroplating facility, as well as analytical sampling data that demonstrate the pre sence of the hazardous substances lead and chromium in source areas, establishes that lead and chromium are associated with the site. Chromium electroplating operations were conducted on the Walton & Lonsbury Inc. property between 1940 and 2007 [15, p. 2; 23, pp. 5 - 6]. In a 1983 Facility Annual Report submitted to the Commonwealth of Massachusetts, Walton & Lonsbury Inc. identified that “chrome sludge from plating process” was generated at a rate of 1,500 gallons a year [81, pp. 1, 7]. According to a chemical use inventory list included in a 1989 report prepared by RCA, on behalf of Walton & Lonsbury Inc., hazardous chemicals used at the property included chromic acid [24, pp. 16 - 17 , 77 ]. A 1989 Annual Report prepar ed by Walton & Lonsbury Inc. identified the facility as a large quantity generator and on - site treatment, storage, or disposal facility generating “chrome plating rinse water” and “sludge” at a rate of 10,800 gallons per year [85, pp. 1 - 2, 10]. A 1991 Haza rdous Waste Report submitted by Walton & Lonsbury Inc. to EPA identified on - site wastes generated including “corrosive chromic - acid - contaminated solid debris, from chrome - plating operation”; “ chromic acid in water ” ; and “chromic - acid contaminated steel duc twork ventilation system for chrome - plating operation” [86, pp. 1, 3 - 4, 7]. File documentation indicates that in 2007, 4,200 gallons of chromic acid solution were transported from the Walton & Lonsbury Inc. property for disposal and/or treatment, and a 200 8 hazardous waste manifest documents the transport of 4,010 gallons of chromic acid from the Walton & Lonsbury Inc. proper ty in Attleboro, MA [80, pp. 26, 28; 84]. Lead has also been identified as having been used in former operational processes on the pro perty [15, pp. 2 - 3]. The Walton & Lonsbury Inc. facility building contained a lead smelter and exhaust hood associated with the manufacture of plumbing components involved in the plating process [15, p. 3]. Through chemical analysis of source samples collected during the 2012 EPA SR, the hazardous substances chromium and lead have been documented to be associated with six sources, which each have a Containment Factor value of 10 for release via overland migra tion and/or flood (see the Source Characterization section for Source Nos. 1 through 6). The presence of chromium and lead at elevated concentrations in Source Nos. 1 through 6, and the documentation via chemical analysis of an observed release of these su bstances to Areas A, B, and C, support at least partial attribution of the hazardous substances to releases from the site [1, p. 51588, Section 2.2.2]. A review of available information was conducted to determine other potential sources of chromium andSoil Exposure Resident Population Threat

Walton & Lonsbury Inc. 128 HRS Documentation Record MAD001197755 5 September 2012 le ad contamination to the site. This review included a search of the Searchable Waste Site List/Site Files for MassDEP, and a review of the E PA CERCLIS and RCRA databases. The MassDEP database allows sites and reportable releases to be searched by various c riteria, and allows users to retrieve a report once the associated data have been approved by MassDEP for public viewing. As part of the search for other nearby potential chromium and lead sources, the MassDEP database was queried for records for the “Town of Att leboro”. A total of 309 spill records were identified based on this criterion (“ Town of Attleboro” ) [102, pp. 1 - 7]. The search was further refined to include reportable releases within 1⁄2 - mile of the Walton & Lonsbury Inc. property. The search yielde d 25 records of reportable releases on the following streets: Walton Street, Deanville Road, Holden Street, Newcomb Street, Water Street, West Street, Townhouse Road, and North Avenue. The majority (14 records) listed “oil” as the chemical type; six record s listed “hazardous material” as the chemical type; one record listed “oil and hazardous material” as the chemical type; and four records did not list the chemical type. Three of these releases are associated with the Walton & Lonsbury Inc. property [102, pp. 1 - 3]. A review of the online documentation of the remaining incidents involving oil and hazardous materials or undefined contaminants (excluding releases from the Walton & Lonsbury Inc. property) indicated that none of the incidents involved or identif ied the presence of chromium or lead above background levels [93, pp. 35 - 40; 94, pp. 39 - 40; 95, p. 37; 96, pp. 23 - 25; 97, p. 16; 98, pp. 3 - 6; 99, p. 6; 100, p. 10; 101, pp. 28 - 29; 116, p. 1; 117, pp. 13 - 16, 226, 231 - 232; 118, p. 1; 119, p. 11]. A review of the EPA CERCLIS and RCRA databases identified eight CERCLIS and 188 RCRA sites in Attleboro, MA, including Walton & Lonsbury Inc. [104, pp. 1 - 2; 105, pp. 1 - 73]. The seven remaining sites identified in the CERCLIS database search (other than Walton & Lon sbury Inc. ) were all located downstream or south of the Walton & Lonsbury Inc. property, and two of the facilities were located greater than 4 miles from the Walton & Lonsbury Inc. property [11; 106, pp. 1 - 4]. The RCRA database search was further refined to include only NAIC Code 332813 (electroplating). The search identified seven electroplating fa cilities, including the Walton & Lonsbury Inc. property [106, pp. 1 - 4]. The remaining six facilities identified i n the RCRA database search were located downstream or south of the Walton & Lonsbury Inc. property [11; 106, pp. 1 - 4]. Previous reports prepared by RCA, on behalf of Walton & Lonsbury Inc., indicated that stormwater runoff/overland flow from the Walton & Lonsbury Inc. property historically flowed toward the wetland located south of the property, and RCA identified surface water run - off as a potential source of chromium contamination to the wetland [11, p. 2; 17, p. 8 - 9, 11 ; 23, p. 47; 24, pp. 11 , 13 , 19 ; 25, p. 32]. Based on on - site observations made during 2012 EPA SR sampling activities, surface water runoff currently flows off the Walton & Lonsbury Inc. property in a southeasterly direction toward a low - lying area of open water at PPE No. 2 [18, p. 29; 103, p. 4]. From PPE No. 2, surface water flows from the area of open water to the wetland area south of the Walton & Lonsbury Inc. property [19, p. 2, 6; 28, p. 10; 103, p. 2]. A Surface Impoundment Source (Source No. 3), located within the wetlands sou th of the Walton & Lonsbury Inc. property, has been evaluated and documented to contain chromium and lead (see Source No. 3 Characterization). In addition, 8.5 acres of wetlands with 0.811 miles of wetland frontage , located south of the Walton & Lonsbury I nc. property and adjacent to and upgradient of Area A, have been evaluated and documented to have been impacted by an observed release of chromium and lead (see Surface Water Migration Pathway). Based on analytical sampling results, on - site observations, a nd documentation provided by the City of Attleboro, MA Department of Public Works, Source No. 3 exhibits evidence of hazardous substance migration and a lack of maintained diking (see the Hazardous Substances Available to Pathway section of Source No. 3) [ 18, pp. 25, 27 - 28; 21; 28, pp. 37, 65; 32, p. 11; 53, pp. 1, 12]. Based on site topography and on - site observations, the low - lying areas along the western portions of residential properties along North Avenue, within Area A, are subject to surface water flooding from theSoil Exposure Resident Population Threat

Walton & Lonsbury Inc. 129 HRS Documentation Record MAD001197755 5 September 2012 contaminated wetlands south of the Walton & Lonsbu ry Inc. property [11; 18, pp. 15 - 16, 23; 19, pp. 2, 6; 109, pp. 1, 5 ]. D rainage problems have been documented for surface water within the wetlands south of the Walton & Lonsbury Inc. property, because the drainage culvert, which extends south - southeast fr om the wetlands through piping underneath Deanville Road, is damaged and partially blocked [16, p. 8; 21]. Low - lying areas in the northern portions of multiple properties along the southern side of Deanville Road, including residential properties along Are a A , have been documented to be subject to flooding from surface water flowing across Deanville Road from the wetland [18, pp. 16, 28 ; 21 ]. Investigations conducted by RCA, on behalf of Walton & Lonsbury Inc., have identified a dissolved chromium ground water plume associated with the Walton & Lonsbury Inc. property; and have identified ground water - to - surface - water transport as an active mechanism for contaminant transport from the Walton & Lonsbury Inc. property to residential properties along Paulette Lane, and to Bliss Brook and downstream freshwater surface water b odies [23, pp. 44, 47, 69 - 70]. Analytical results of samples collected during previous investigations documented elevated concentrations of chromium and hexavalent chromium in pooled surface water and shallow ground water at residential properties along Paulette Lane, as well as associated lead and chromium contamination in soils at residential properties along Paulette Lane (see the Site Sum mary section for a more detailed discussion) [16, pp. 9 - 10; 23, pp. 37, 95; 29, pp. 15, 38 - 39, 52 ]. In addition, numerous investigations, including the 2001 RCA Phase IIC investigation, the 2005 EPA Site Inspection, the 2011 MassDEP surface water sampling event, and the 2012 EPA SR, have identified impacts to surface water and sediments along Bliss Brook associated with ground water - to surface water contaminant release from the Walton & Lonsbury Inc. property (see the Source Identification section of Source No. 5 for a more detailed discussion). Areas B and C are located downgradient of the PPE for ground water - to - surface water release from the Walton & Lonsbury Inc. property. Based on site topography, flood zone data, an interview with a property owner, and on - site observations, the low - lying areas of residential properties along Area B , adjacent to Bliss Brook, are known or suspected to be subject to surface water flooding from Bliss Brook [18, pp. 17 - 19, 22 - 25; 109, pp. 1 - 2, 5 ]. Based on site topography , flood zone data, and on - site observations, the low - lying areas of residential properties along Area C , adjacent to Bliss Brook, are also inferred to be subject to surface water flooding from Bliss Brook [18, pp. 20 - 21, 24; 109, pp. 1 - 2, 5 ]. Area Hazard ous Waste Quantity The Hazardous Waste Quantit y of Areas A, B, and C were calculated based on the Area Assigned Value of contaminated soil. The Hazardous Constituent Quantity and Hazardous Wastestream Quantity Values were not evaluated for Areas A, B, and C because insufficient information was available , as described in the sections below [1, p. 51647, Table 5 - 2]. An area of “contaminated soil” cannot be evaluated for Hazardous Waste Quantity for the Soil Exposure Pathway based on its volume [1, p. 51647, Table 5 - 2].

- Hazardous Constituent Quantity : Description The H azardous C onstituent Q uantity for Areas A, B, and C could not be adequately determined according to the HRS Rule requirements; that is, the total mass of all CERCLA hazardous substances in the areas of observed contamination is not known and cannot be estimated with reasonable confidence [1, pp. 51590 - 51591 (Section 2.4.2.1.1)]. Insufficien t historical and current data (m anifest s, PRP records, State records, permits, w aste concentration data, etc.) are available to adequately calculate the total mass of all CERCLA hazardous subs tances in the areas of observed contamination . Therefore, there is insufficient information to calculate the H azardous C onstituent Q uantity for Areas A, B, and C with reasonable confidence.Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 130 HRS Documentation Record MAD001197755 5 September 2012 Table 57 - Hazardous Constituent Quantities for Areas A, B, and C Hazardous Substance Constituent Quantity (pounds) References NS (Insufficient Information) NS = Not Scored. Sum (pounds): Hazardous Constituent Quantity Assigned Value : Not Evaluated Hazardous Constituent Quantity Complete? No

- Hazardous Wastestream Quantity : Description The H azardous W astestream Q uantity for Areas A, B, and C could not be adequately determined according to the HRS Rule requirements; that is, the total mass of all hazardous wastestreams and CERCLA pollutants an d contaminants in the areas of observed contamination is not known and cannot be estimated with reasonable confidence [1, p. 51591 (Section 2.4.2.1.2)]. Insufficien t historical and current data (m anifest s, PRP records, State records, permits, waste concent ration data, a nnual reports, etc.) are available to adequately calculate the total mass of all hazardous wastestreams and CERCLA pollutants and contaminants for the areas of observed contamination . Therefore, there is insufficient information to adequately calculate or extrapolate the H azardous W astestream Q uantity for Areas A, B, and C with reasonable confidence. Table 58 - Hazardous Wastestream Quantities for Areas A, B, and C Hazardous Wastestream Wastestream Quantity (pounds) References NS (Insufficient Information) NS = Not Scored. Sum (pounds): Wastestream Quantity/5,000 (Ref. 1, Table 5 - 2): Hazardous Wastestream Quantity Assigned Value: Not Evaluated

- Volume:

Description Since volume measurement of Areas A, B, and C are not applicable for the Soil Exposure Pathway, a value of 0 is assigned [1, pp. 51591, Section 2.4.2.1.3, 51647, Section 5.1.2.2, Table 5 - 2].Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 131 HRS Documentation Record MAD001197755 5 September 2012 Table 59 – Volume for Areas A, B, and C Source Type Description (# drums or dimensions) Units (yd 3 /gal) References NS (Insufficient Information) Sum (yd 3 /gal): Equation for Assigning Value (Ref. 1, Table 5 - 2): Volume Assigned Value: 0

- Area: Description Area A: The area of Area A ( 11,980.80 ft 2 ) includes the sampling locations which document observed contamination with chromium and lead, and the area s lying between these locations, with the exception of areas which are cover ed with maintained asphalt road and permanent water cover (including wetlands) [1, p. 51646, Section 5.0.1; 28, pp. 67, 69 - 73, 83; 53, p. 9; 60, pp. 7, 8; 71 , pp. 1 - 2, 9 - 10 ; 72, pp. 33, 34, 36, 37, 42 - 46, 6 3 , 74, 75, 78 ]. The area lying between contaminated Area A surface soil/source sample locations is inferred to be contaminated due to the likely mechanism of contaminant transport (flooding). All of the Area A surface soil/source sample locations and the entirety of the area of inferred contamination lying between these locations are within an area of t he same topog raphical elevation [109, pp. 1 , 5]. In addition, Area A surface soil/source sample locations west of North Avenue and north of Deanville Road, and the areas of inferred contamination lying between these locations, are adjacent to a wetland and within the same topographical elevation [10 9, pp. 1 , 5]. Recent on - site observations and documentation have indicated that surface water occasionally flood s from the wetland to the south across Deanville Road due to drainage problems within the wetland [1 8, p. 28; 21]. The area of inferred contamination between contaminated Area A surface soil/source sample locations on properties south of Deanville Road is presumed to be contaminated due to the area topography, observed flooding in nearby areas, and an in terview with a property owner [18, p. 16, 28 ; 109, pp. 1 , 5 ]. The area of Area A subject to observed contamination was determined by measuring the area between six surface soil sample locations [P - 01 - SS - 02B, P - 01 - SS - 03B, P - 04 - SS - 06, P - 06 - SS - 02, P - 07 - SS - 02/P - 30 - SS - 02 (field duplicate), and P - 09 - SS - 07] , recorded with a GPS unit, using GIS software [ 71 , pp. 1 - 2, 9 - 10 ]. The total area between contaminated surface soil sample locations, including areas covered w ith maintained asphalt road and permanent water cover, was determined to be 22,950.46 ft 2 [71 , p. 2 ]. Areas which are covered by permanent or otherwise maintained, essentially impermeable cover must be excluded in evaluating the Soil Exposure Pathway [1, p . 51646, Section 5.0.1]. The area covered with maintained asphalt road and permanent water cover (including wetlands) was determined to be 10,969.66 ft 2 based on on - site observations, wetland delineation activities, and an interpretation of aerial imagery using GIS software [ 71 , pp. 1 - 2, 9 - 10 ]. Area A therefore comprises 11,980.80 ft 2 of contaminated soil ( 22,950.46 ft 2

- 10,969.66 ft 2 = 11,980.80 ft 2 ) , which meets the criteria for observed contamination, where hazardous waste generated from plating operations conducted on the Walton & Lonsbury Inc. property has been disposed of or has come to be located [1, p. 51646, Section 5.0.1; 71 , pp. 1 - 2 , 9 - 10 ].Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 132 HRS Documentation Record MAD001197755 5 September 2012 Area B: The area of Area B ( 11,756.69 ft 2 ) includes the sampling locations which document observed contamination with chromium and lead, and the are as lying between these locations, with the exception of areas which are covered with a shed and a pool and permanent water cover (including wetlands) [1, p. 51646, Section 5.0.1; 28, pp. 69, 70, 78 - 80, 83; 53, pp. 9, 10; 60, p. 9; 61, pp. 7, 8; 71 , pp. 1, 3, 11 - 13 ; 72, pp. 35, 38 - 41, 47 - 54, 64, 76, 78 - 81]. T he area lying between contaminated Area B surface soil sample locations is inferred to be contaminated due to the likely mechanism of contaminant transport (flooding). All of the Area B surface soil sample locations and the entirety of the area of inferred contamination lying between these locations are within an area of the same topographical elevation [109, pp. 1 - 2, 5]. In addition, Area B surface soil sample locations and the areas of inferred contamination lying between these locations are within or in close proximity to the 100 - year flood plain, and adjacent to wetland areas and/or Bliss Brook [109, pp. 1 - 2, 5 ]. Based on on - site observations and an interview with a resident , the low - lying areas of residential properties along Area B , adjacent to Bliss B rook, are known or suspected to be subject to surface water flooding from Bliss Brook [18, pp. 17 - 19, 22 - 25]. Interviews with a resident at one property along Area B revealed that Bliss Brook would routinely flood the lawn on his and adjacent properties [1 8, pp. 18 - 19]. Therefore, based on area topography, on - site observations, interviews, and flood plain data, the areas of inferred contamination lying between contaminated Area B surface soil sample locations are presumed to be contaminated due to the likel y mechanism of contaminant transport (flooding) [ 18, pp. 17 - 19, 22 - 25 ; 109, pp. 1 - 2, 5]. The area of Area B subject to observed contamination was determined by measuring the area between 10 surface soil sample locations [P - 03 - SS - 05, P - 05 - SS - 06, P - 05 - SS - 05, P - 20 - SS - 04A/P - 31 - SS - 04A (field duplicate), P - 20 - SS - 01, P - 19 - SS - 03, P - 18 - SS - 07, P - 18 - SS - 08, P - 24 - SS - 04, and P - 17 - SS - 07A/B] , recorded with a GPS unit, using GIS software [ 71 , pp. 1, 3, 11 - 13 ]. The total area between contaminated surface soil samp le locations, including areas covered w ith a shed and a pool and permanent water cover , was determined to be 50,118.57 ft 2 [ 71 , pp. 1, 3, 11 - 13 ]. Areas which are covered by permanent or otherwise maintained, essentially impermeable cover must be excluded i n evaluating the Soil Exposure Pathway [1, p. 51646, Section 5.0.1]. The area covered with a shed and pool and permanent water cover (including wetlands) was determined to be 38,361.88 ft 2 based on on - site observations, wetland delineation activities, and an interpretation of aerial imagery using GIS software [ 71 , pp. 1, 3, 11 - 13 ]. Area B therefore comprises 11,756.69 ft 2 of contaminated soil ( 50,118.57 ft 2

- 38,361.88 ft 2 = 11,756.69 ft 2 ) , which meets the criteria for observed contamination, where hazar dous waste generated from plating operations conducted on the Walton & Lonsbury Inc. property has been disposed of or has come to be located [1, p. 51646, Section 5.0.1; 71 , pp. 1, 3, 11 - 13 ]. Area C: The area of Area C ( 4,350.89 ft 2 ) includes the sampling locations which document observed contamination with chromium and lead, and the area s lying between these locations, with the exception of areas which are covered with permanent water cover (including wetlands) [1, p. 51646, Section 5.0.1; 28 , pp. 80 - 82; 53, p. 10; 60, pp. 8, 9; 61, p. 7; 71 , pp. 1, 3 - 4, 14 ; 72, pp. 55 - 61, 75, 79, 80]. The area lying between contaminated Area C surface soil sample locations is inferred to be contaminated due to the likely mechanism of contaminant transport (fl ooding). All of the Area C surface soil sample locations and the entirety of the area of inferred contamination lying between these locations are within an area of the same topographical elevation [109, pp. 1 - 2, 5 ]. In addition, Area C surface soil sample locations and the areas of inferred contamination lying between these locations are within or in close proximity to the 100 - year flood plain, and adjacent to wetland areas and/or Bliss Brook [109, pp. 1 - 2, 5 ]. Therefore, based on area topography an d flood plain data, the areas of inferred contamination lying between Area C surface soil sample locations are presumed to be contaminated due to the likely mechanism of contaminant transport (flooding) [18, pp. 17 - 19, 22 - 25; 109, pp. 1 - 2, 5 ].Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 133 HRS Documentation Record MAD001197755 5 September 2012 The area of Area C subject to observed contamination was determined by measuring the area between five surface soil sample locations [P - 23 - SS - 06, P - 23 - SS - 02, P - 22 - SS - 09A, P - 22 - SS - 10A, and P - 22 - SS 07] , recorded with a GPS unit, using GIS software [ 71 , pp. 1, 3 - 4, 14 ]. The total area between contaminated surface soil sample locations, including areas covered w ith permanent water cover (including wetlands), was determined to be 10,536.43 ft 2 [ 71 , pp. 1, 3 - 4, 14 ]. Areas which are covered by permanent, essentially impermeable cover must be excluded in evaluating the Soil Exposure Pathway [1, p. 51646, Section 5.0.1]. The area covered with permanent water cover (including wetlands) was determined to be 6,185.54 ft 2 based on on - site observations, wetland delineation activities, and an interpretation of aerial imagery using GIS software [ 71 , pp. 1, 3 - 4, 14 ]. Area C therefore comprises 4,350.89 ft 2 of contaminated soil ( 10,536.43 ft 2

- 6,185.54 ft 2 = 4,350.89 ft 2 ) , which meets the criteria for observed contamination, where hazardous waste generated from plating operations conducted on the Walton & Lonsbury Inc. property has been disposed of or has come to be located [1, p. 51646, Section 5.0.1; 71 , pp. 1, 3 - 4, 14 ]. Table 6 0 - Area Area Source Type Units (ft 2 ) References

A Contaminated Soil 11,980.80 28, pp. 67, 69 - 73, 83; 53, p. 9; 60, pp. 7, 8; 71 , pp. 1 - 2, 9 - 10 ; 72, pp. 33, 34, 36, 37, 42

- 46, 6 3 , 74, 75, 78 B Contaminated Soil 11,756.69 28, pp. 69, 70, 78 - 80, 83; 53, pp. 9, 10; 60, p. 9; 61, pp. 7, 8; 71 , pp. 1, 3, 11 - 13 ; 72, pp. 35, 38 - 41, 47 - 54, 64, 76, 78 - 81 C Contaminated Soil 4,350.89 28, pp. 80 - 82; 53, p. 10; 60, pp. 8, 9; 61, p. 7; 71 , pp. 1, 3 - 4, 14 ; 72, pp. 55 - 61, 75, 79, 80 ft 2 = Square feet. Sum (ft 2 ): 11,980.80 ft 2 Equation for Assigning Value (Ref. 1, Table 5 - 2): Area ÷ 34,000 Area A Assigned Value: 0. 35 2 Sum (ft 2 ): 11,756.69 ft 2 Equation for Assigning Value (Ref. 1, Table 5 - 2): Area ÷ 34,000 Area B Assigned Value: 0.3 4 5 Sum (ft 2 ): 4,350.89 ft 2 Equation for Assigning Value (Ref. 1, Table 5 - 2): Area ÷ 34,000 Area C Assigned Value: 0. 1 28Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 134 HRS Documentation Record MAD001197755 5 September 2012 Area Hazardous Waste Quantity Value : The Hazardous Waste Quantity Value for Areas A, B, and C were assigned based on the Area Assigned Values for Area A (0. 3 52 ), Area B ( 0.3 45 ), and Area C (0. 1 28 ) [1, p. 51591, Section 2.4.2.1.5, p. 51646, Section 5.0.1, 51647, Table 5 - 2]. Although potentiall y available to the Soil Exposure Pathway , a dd itional areas of observed contamination associated with Source Nos. 1 and 2 were not evaluated as part of this HRS documentation record . I nclusion of these areas would potentially increase the Hazardous Waste Qu antity Factor Value for the Soil Exposure Pathway . 5 .1 RESIDENT POPULATION THREAT 5.1.1 LIKELIHOOD OF EXPOSURE Three areas of observed contamination (Areas A, B, and C) are located within 200 feet of residences; therefore a Resident Population Threat Likelihood of Exposure Factor Category Value of 550 is assigned [1, p. 51646, Section 5.1.1]. Table 6 1 - Resident Population T hreat Likelihood of Exposure Factor Area Sample ID Distance of Population/Resource from Area of Observed Contamination References Area A: A P - 01 - SS - 02B Surface soil sample P - 01 - SS - 02B was collected 108 feet from the residence located on the property (Map No. 59, Lot No. 190A) . 18, p. 14; 28, p. 67; 92, pp. 1 - 3 A P - 01 - SS - 03B Surface soil sample P - 01 - SS - 03B was collected 115 feet from the residence located on the property (Map No. 59, Lot No. 190A) . 18, p. 14; 28, p. 67; 92, pp. 1 - 3 A P - 04 - SS - 03 Surface soil sample P - 04 - SS - 03 was collected 68 feet from the residence located on the property (Map No. 59, Lot No. 225) . 18, p. 14; 28, p. 69; 92, pp. 1 - 3 A P - 04 - SS - 06 Surface soil sample P - 04 - SS - 06 was collected 48 feet from the residence located on the property (Map No. 59, Lot No. 225) . 18, p. 14; 28, p. 70; 92, pp. 1 - 3 A P - 06 - SS - 02 Surface soil sample P - 06 - SS - 02 was collected 24 feet from the residence located on the property (Map No. 59, Lot No. 220) . 18, p. 14; 28, p. 71; 92, pp. 1 - 2, 4 A P - 06 - SS - 03 Surface soil sample P - 06 - SS - 03 was collected 20 feet from the residence located on the property (Map No. 59, Lot No. 220) . 18, p. 14; 28, p. 71; 92, pp. 1 - 2, 4 A P - 07 - SS - 02/ P - 30 - SS - 02 Surface soil sample P - 07 - SS - 02/P - 30 - SS - 02 was collected 61 feet from the residence located on the property (Map No. 49, Lot No. 113) . 18, p. 14; 28, p. 72, 83 ; 92, pp. 1 - 2, 4 A P - 09 - SS - 02 Surface soil sample P - 09 - SS - 02 was collected 53 feet from the residence located on the property (Map No. 49, Lot No. 114B) . 18, p. 14; 28, p. 72; 92, pp. 1 - 2, 4Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 135 HRS Documentation Record MAD001197755 5 September 2012 Table 6 1 - Resident Population T hreat Likelihood of Exposure Factor Area Sample ID Distance of Population/Resource from Area of Observed Contamination References A P - 09 - SS - 07 Surface soil sample P - 09 - SS - 07 was collected 9 feet from the residence located on the property (Map No. 49, Lot No. 114B) . 18, p. 14; 28, p. 73; 92, pp. 1 - 2, 4 Area B : B P - 03 - SS - 05 Surface soil sample P - 03 - SS - 05 was collected 148 feet from the residence located on the property (Map No. 49, Lot No. 112) . 18, p. 14; 28, p. 69; 92, pp. 1 - 2, 5 B P - 05 - SS - 01 Surface soil sample P - 05 - SS - 01 was collected 109 feet from the residence located on the property (Map No. 49, Lot No. 109) . 18, p. 14; 28, p. 70; 92, pp. 1 - 2, 6 B P - 05 - SS - 04 Surface soil sample P - 05 - SS - 04 was collected 82 feet from the residence located on the property (Map No. 49, Lot No. 109) . 18, p. 14; 28, p.70; 92, pp. 1 - 2, 6 B P - 05 - SS - 05 Surface soil sample P - 05 - SS - 05 was collected 43 feet from the residence located on the property (Map No. 49, Lot No. 109) . 18, p. 14; 28, p.70; 92, pp. 1 - 2, 6 B P - 05 - SS - 06 Surface soil sample P - 05 - SS - 06 was collected 28 feet from the residence located on the property (Map No. 49, Lot No. 110) . 18, p. 14; 28, p.70; 92, pp. 1 - 2, 5 B P - 17 - SS - 07A Surface soil sample P - 17 - SS - 07A was collected 115 feet from the residence located on the property (Map No. 49, Lot No. 94) . 18, p. 14; 28, p. 78; 92, pp. 1 - 2, 6 B P - 17 - SS - 07B Surface soil sample P - 17 - SS - 07B was collected 115 feet from the residence located on the property (Map No. 49, Lot No. 94) . 18, p. 14; 28, p. 78; 92, pp. 1 - 2, 6 B P - 18 - SS - 07 Surface soil sample P - 18 - SS - 07 was collected 64 feet from the residence located on the property (Map No. 49, Lot No. 96) . 18, p. 14; 28, p. 79; 92, pp. 1 - 2, 7 B P - 18 - SS - 08 Surface soil sample P - 18 - SS - 08 was collected 57 feet from the residence located on the pr operty (Map No. 49, Lot No. 96). 18, p. 14; 28, p. 79; 92, pp. 1 - 2, 7 B P - 18 - SS - 09 Surface soil sample P - 18 - SS - 09 was collected 56 feet from the residence located on the property (Map No. 49, Lot No. 96) . 18, p. 14; 28, p. 79; 92, pp. 1 - 2, 7 B P - 19 - SS - 03 Surface soil sample P - 19 - SS - 03 was collected 102 feet from the residence located on the property (Map No. 49, Lot No. 97A) . 18, p. 14; 28, p. 79; 92, pp. 1 - 2, 7 B P - 20 - SS - 01 Surface soil sample P - 20 - SS - 01 was collected 166 feet from the residence located on the property (Map No. 49, Lot No. 97) . 18, p. 14; 28, p. 80; 92, pp. 1 - 2, 7 B P - 20 - SS - 04A/ P - 31 - SS - 04A Surface soil sample P - 20 - SS - 04A/P - 31 - SS - 04A was collected 173 feet from the residence located on the property (Map No. 49, Lot No. 97) . 18, p. 14; 28, p. 80; 92, pp. 1 - 2, 7Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 136 HRS Documentation Record MAD001197755 5 September 2012 Table 6 1 - Resident Population T hreat Likelihood of Exposure Factor Area Sample ID Distance of Population/Resource from Area of Observed Contamination References B P - 24 - SS - 04 Surface soil sample P - 24 - SS - 04 was collected 49 feet from the residence located on the property (Map No. 49, Lot No. 95) . 18, p. 14; 28, p. 83; 92, pp. 1 - 2, 7 Area C : C P - 21 - SS - 03 Surface soil sample P - 21 - SS - 03 was collected 103 feet from the residence located on the property (Map No. 49, Lot No. 125) . 18, p. 14; 28, p. 80; 92, pp. 1 - 2, 8 C P - 21 - SS - 04 Surface soil sample P - 21 - SS - 04 was collected 123 feet from the residence located on the property (Map No. 49, Lot No. 125) . 18, p. 14; 28, p. 80; 92, pp. 1 - 2, 8 C P - 22 - SS - 07 Surface soil sample P - 22 - SS - 07 was collected 182 feet from the residence located on the property (Map No. 49, Lot No. 126) . 18, p. 14; 28, p. 81; 92, pp. 1 - 2, 8 C P - 22 - SS - 09A Surface soil sample P - 22 - SS - 09A was collected 200 feet from the residence located on the property (Map No. 49, Lot No. 126) . 18, p. 14; 28, p. 82; 92, pp. 1 - 2, 8 C P - 22 - SS - 10A Surface soil sample P - 22 - SS - 10A was collected 174 feet from the residence located on the property (Map No. 49, Lot No. 126) . 18, p. 14; 28, p. 82; 92, pp. 1 - 2, 8 C P - 23 - SS - 02 Surface soil sample P - 23 - SS - 02 was collected 93 feet from the residence located on the property (Map No. 49, Lot No. 124) . 18, p. 14; 28, p. 82; 92, pp. 1 - 2, 8 C P - 23 - SS - 06 Surface soil sample P - 23 - SS - 06 was collected 20 feet from the residence located on the property (Map No. 49, Lot No. 124) . 18, p. 14; 28, p. 82; 92, pp. 1 - 2, 8 Resident Population Threat Likelihood of Exposure Factor Category Value : 550 5.1.2 WASTE CHARACTERISTICS 5.1.2.1 Toxicity Table 6 2 – Toxicity Factor Hazardous Substance Toxicity Factor Value References Chromium 10,000 2, p. BI - 3 Lead 10,000 2, p. BI - 8 The hazardous substance with the highest toxicity is used to assign the value to the Toxicity Factor for the Residential Population Threat [1, p. 51646, Section 5.1.2.1]. For this HRS documentation record, theSoil Exposure Resident Population Threat

Walton & Lonsbury Inc. 137 HRS Documentation Record MAD001197755 5 September 2012 toxicity factor f or chromium (10,000) is applied [2, p. BII - 20]. The toxicity value for lead is also 10,000; however, no hazardous substance benchmark for lead is listed in SCDM for the soil pathway [ 2, p. BII 20]. Toxicity Factor Value: 10,000 5.1.2.2 Hazardous Waste Quantity The Hazardous Waste Quantity Factor Value was assigned as s pecified in Sections 2.4.2 and 5.1.2.2, based on the Area Factor Value for Areas A, B, and C. Table 6 3 - Hazardous Waste Quantity Factor Area Letter Source Type Area Hazardous Waste Quantity A Contaminated Soil 0. 35 2 

### B Contaminated Soil 0.3 4 5 

### C Contaminated Soil 0. 1 28 Sum of Values: 0.8 25 Based on HRS Section 2.4.2.2, if the Hazardous Constituent Quantity is not adequately determined for one or more areas and if any target for the Soil Exposure Pathway is subject to Level I or Level II concentrations, a factor value is assigned from Table 2 - 6 or a value of 10, whichever is greater, as the Hazardous Waste Quantity Factor Value for that pathway [1, pp. 51591, 51592, Section 2.4.2.2]. Hazardous Waste Quantity Factor Value (1, p. 51591, Ta ble 2 - 6): 10 5.1.2.3 Calculation of Waste Characteristics Factor Category Value The Toxicity Factor Value for chromium (10,000) is multiplied by the Hazardous Waste Quantity Factor Value for the site (10) in order to determine the Waste Characteristics Product, subject to a maximum value of 1 × 10 8 [1, p. 51592, Section 2.4.3.1]. 10,000 × 10 = 1 × 10 5 Toxicity Factor Value: 10,000 Hazardous Waste Quantity Factor Value: 10 Toxicity Factor Value × Hazardous Waste Quantity Factor Value: 1 × 10 5 From HR S Table 2 - 7, a Waste Characteristics Product of 1 × 10 5 is assigned a Waste Characteristics Factor Category Value of 18 [1, p. 51592, Section 2.4.3.1]. Waste Characteristics Factor Category Value (1, p. 51592, Table 2 - 7): 18Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 138 HRS Documentation Record MAD001197755 5 September 2012 5.1.3 TARGETS Level I Conce ntrations Sample ID: P - 04 - SS - 06 Area Letter: A Reference for Benchmark: 2, BII - 15 Reference for Hazardous Substance Concentration: 18, p. 15; 60, p. 7; 72, p. 37 Table 6 4 – Hazardous Substance Benchmark Concentrations Hazardous Substance Hazardous Substance Concentration (units) Benchmark Concentration Benchmark Chromium 253 mg/Kg 230 mg/Kg Reference Dose mg/Kg = Milligrams per Kilogram . Sample ID: P - 07 - SS - 02 Area Letter: A Reference for Benchmark: 2, BII - 15 Reference for Hazardous Substance Concentration: 18, p. 15; 60, p. 7; 72, p. 44 Table 6 5 – Hazardous Substance Benchmark Concentrations Hazardous Substance Hazardous Substance Concentration (units) Benchmark Concentration Benchmark Chromium 

### 617 mg/Kg 230 mg/Kg Reference Dose mg/Kg = Milligrams per Kilogram . Sample ID: P - 09 - SS - 07 Area Letter: A Reference for Benchmark: 2, BII - 15 Reference for Hazardous Substance Concentration: 18, p. 16; 60, p. 8; 72, p. 46 Table 6 6 – Hazardous Substance Benchmark Concentrations Hazardous Substance Hazardous Substance Concentration (units) Benchmark Concentration Benchmark Chromium 

### 569 mg/Kg 230 mg/Kg Reference Dose mg/Kg = Milligrams per Kilogram .Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 139 HRS Documentation Record MAD001197755 5 September 2012 Sample ID: P - 30 - SS - 02 (field duplicate of P - 07 - SS - 02) Area Letter: A Reference for Benchmark: 2, BII - 15 Reference for Hazardous Substance Concentration: 18, p. 15; 60, p. 8; 72, p. 6 3 Table 67 – Hazardous Substance Benchmark Concentrations Hazardous Substance Hazardous Substance Concentration (units) Benchmark Concentration Benchmark Chromium 

### 536 mg/Kg 230 mg/Kg Reference Dose mg/Kg = Milligrams per Kilogram . Sample ID: P - 05 - SS - 01 Area Letter: B Reference for Benchmark: 2, BII - 15 Reference for Hazardous Substance Concentration: 18, p. 22; 61, p. 7; 72, p. 38 Table 68 – Hazardous Substance Benchmark Concentrations Hazardous Substance Hazardous Substance Concentration (units) Benchmark Concentration Benchmark Chromium 

### 261 mg/Kg 230 mg/Kg Reference Dose mg/Kg = Milligrams per Kilogram . Sample ID: P - 05 - SS - 04 Area Letter: B Reference for Benchmark: 2, BII - 15 Reference for Hazardous Substance Concentration: 18, p. 22; 61, p. 7; 72, p. 39 Table 69 – Hazardous Substance Benchmark Concentrations Hazardous Substance Hazardous Substance Concentration (units) Ben chmark Concentration Benchmark Chromium 

### 258 mg/Kg 230 mg/Kg Reference Dose mg/Kg = Milligrams per Kilogram .Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 140 HRS Documentation Record MAD001197755 5 September 2012 Sample ID: P - 05 - SS - 06 Area Letter: B Reference for Benchmark: 2, BII - 15 Reference for Hazardous Substance Concentration: 18, p. 22; 61, p. 7; 72, p. 41 Table 7 0 – Hazardous Substance Benchmark Concentrations Hazardous Substance Hazardous Substance Concentration (units) Benchmark Concentration Benchmark Chromium 

### 234 mg/Kg 230 mg/Kg Reference Dose mg/Kg = Milligrams per Kilogram . Sample ID: P - 17 - SS - 07A Area Letter: B Reference for Benchmark: 2, BII - 15 Reference for Hazardous Substance Concentration: 18, p. 23; 53, p. 9; 72, p. 47 Table 7 1 – Hazardous Substance Benchmark Concentrations Hazardous Substance Hazardous Substance Concentration (units) Benchmark Concentration Benchmark Chromium 

### 857 mg/Kg 230 mg/Kg Reference Dose mg/Kg = Milligra ms per Kilogram . Sample ID: P - 18 - SS - 07 Area Letter: B Reference for Benchmark: 2, BII - 15 Reference for Hazardous Substance Concentration: 18, p. 18; 61, p. 8; 72, p. 49 Table 7 2 – Hazardous Substance Benchmark Concentrations Hazardous Substance Hazardous Substance Concentration (units) Benchmark Concentration Benchmark Chromium 

### 2,020 mg/Kg 230 mg/Kg Reference Dose mg/Kg = Milligra ms per Kilogram .Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 141 HRS Documentation Record MAD001197755 5 September 2012 Sample ID: P - 18 - SS - 08 Area Letter: B Reference for Benchmark: 2, BII - 15 Reference for Hazardous Substance Concentration: 18, p. 25; 53, p. 9; 72, p. 50 Table 7 3 – Hazardous Substance Benchmark Concentrations Hazardous Substance Hazardous Substance Concentration (units) Benchmark Concentration Benchmark Chromium 

### 1,000 mg/Kg 230 mg/Kg Reference Dose mg/Kg = Milligra ms per Kilogram . Sample ID: P - 18 - SS - 09 Area Letter: B Reference for Benchmark: 2, BII - 15 Reference for Hazardous Substance Concentration: 18, p. 25; 53, p. 9; 72, p. 51 Table 7 4 – Hazardous Substance Benchmark Concentrations Hazardous Substance Hazardous Substance Concentration (units) Benchmark Concentration Benchmark Chromium 

### 270 mg/Kg 230 mg/Kg Reference Dose mg/Kg = Milligra ms per Kilogram . Sample ID: P - 21 - SS - 03 Area Letter: C Reference for Benchmark: 2, BII - 15 Reference for Hazardous Substance Concentration: 18, p. 20; 60, p. 8; 72, p. 55 Table 7 5 – Hazardous Substance Benchmark Concentrations Hazardous Substance Hazardous Substance Concentration (units) Benchmark Concentration Benchmark Chromium 

### 327 mg/Kg 230 mg/Kg Reference Dose mg/Kg = Milligra ms per Kilogram .Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 142 HRS Documentation Record MAD001197755 5 September 2012 Sample ID: P - 21 - SS - 04 Area Letter: C Reference for Benchmark: 2, BII - 15 Reference for Hazardous Substance Concentration: 18, p. 20; 60, p. 8; 72, p. 56 Table 7 6 – Hazardous Substance Benchmark Concentrations Hazardous Substance Hazardous Substance Concentration (units) Benchmark Concentration Benchmark Chromium 799 mg/Kg 230 mg/Kg Reference Dose mg/Kg = Milligra ms per Kilogram . Sample ID: P - 22 - SS - 07 Area Letter: C Reference for Benchmark: 2, BII - 15 Reference for Hazardous Substance Concentration: 18, p. 20; 61, p. 7; 72, p. 57 Table 77 – Hazardous Substance Benchmark Concentrations Hazardous Substance Hazardous Substance Concentration (units) Benchmark Concentration Benchmark Chromium 

### 271 mg/Kg 230 mg/Kg Reference Dose mg/Kg = Milligra ms per Kilogram . Sample ID: P - 23 - SS - 02 Area Letter: C Reference for Benchmark: 2, BII - 15 Reference for Hazardous Substance Concentration: 18, p. 21, 60, p. 9; 72, p. 60 Table 7 8 – Hazardous Substance Benchmark Concentrations Hazardous Substance Hazardous Substance Concentration (units) Benchmark Concentration Benchmark Chromium 1,180 mg/Kg 230 mg/Kg Reference Dose mg/Kg = Milligra ms per Kilogram .Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 143 HRS Documentation Record MAD001197755 5 September 2012 Sample ID: P - 23 - SS - 06 Area Letter: C Reference for Benchmark: 2, BII - 15 Reference for Hazardous Substance Concentration: 18, p. 21; 60, p. 9; 72, p. 61 Table 79 – Hazardous Substance Benchmark Concentrations Hazardous Substance Hazardous Substance Concentration (units) Benchmark Concentration Benchmark Chromium 833 mg/Kg 230 mg/Kg Reference Dose mg/Kg = Milligra ms per Kilogram . 5.1.3.1 Resident Individual O n - site residences are located within 200 feet of 16 surface soil samples (P - 04 - SS - 06, P - 07 - SS - 02, P - 09 - SS - 07, P - 30 - SS - 02, P - 05 - SS - 01, P - 05 - SS - 04, P - 05 - SS - 06, P - 17 - SS - 07A, P - 18 - SS - 07, P - 18 - SS - 08, P - 18 - SS - 09, P - 21 - SS - 03, P - 21 - SS - 04, P - 22 - SS - 07, P - 23 - SS - 02, and P - 23 - SS - 06) with concentrations of chromium exceeding 100% of the reference dose for chromium ( 230 mg/Kg), within areas of observed contamination; therefore, Level I resident individuals are documented [1, p. 51647, Section 5.1.3; 2, BII 15; 28, pp. 67, 69 - 73, 78 - 83; 53, pp. 9 - 10; 60, pp. 7 - 9; 61, pp. 7 - 8; 72, pp. 33 - 61, 64, 74 - 76, 78 - 81]. A residen t individual is subject to Level I concentrations ; therefore, a Resident Individual Factor Value of 50 is assigned [1, p. 51647, Section 5.1.3.1]. Area Letter s : A, B, and C Level of Contamination (Level I/Level II): Level I Reference: 2, B II - 15; 28, pp. 6 7, 69 - 73, 78 - 83; 53, pp. 9 - 10; 60, pp. 7 - 9; 61, pp. 7 - 8; 72, pp. 33 - 61, 64, 74 - 76, 78 - 81 Resident Individual Factor Value: 50 5.1.3.2 Resident Population 5.1.3.2.1 Level I Concentrations Level I Resident Population Targets Area A: The population of the one residence located at the property designated as “P - 04” (with sample P - 04 - SS 06), identified on the City of Attleboro Tax Assessor’s Map No. 59, as Lot No. 225, was obtained by interviews conducted by a MassDEP representative [18, pp. 13 - 14; 110 , pp. 1 - 2]. Based on documentation provided by MassDEP , two residents occupy the residence at this property, which is located within 200 feet of sample P - 04 - SS - 06 [92 , pp. 1 - 3 ; 110, pp. 1 - 2]. The population of the one residence located at the property des ignated as “P - 07” (with samples P - 07 - SS 02 and field duplicate P - 30 - SS - 02), identified on the City of Attleboro Tax Assessor’s Map No. 49, as Lot No. 113, was obtained by interviews conducted by a MassDEP representative [18, pp. 13 - 14; 110, pp. 1 -Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 144 HRS Documentation Record MAD001197755 5 September 2012 2]. Based on documentation provided by MassDEP, two residents occupy the residence at this property, which is located within 200 feet of samples P - 07 - SS - 02 and P - 30 - SS - 02 [92 , pp. 1 - 2, 4 ; 110, pp. 1 - 2]. The population of the one residence located at the property designated as “P - 09” (with sample P - 09 - SS 07), identified on the City of Attleboro Tax Assessor’s Map No. 49, as Lot No. 114B, was obtained by interviews conducted by WESTON START personnel as part of the EPA SR [18, pp. 13 - 14, 17 - 18]. Based on documentation provided by WESTON START, four residents occupy the residence at this property, which is located within 200 feet of sample P - 09 - SS - 07 [18, pp. 17 - 18; 92 , pp. 1 - 2, 4 ]. Ar ea B: The population of the one residence located at the property designated as “P - 05” (with samples P - 05 - SS 01, P - 05 - SS - 04 , and P - 05 - SS - 06), identified on the City of Attleboro Tax Assessor’s Map No. 49, as Lot No. 109, was provided by the Executive Dire ctor of Attleboro Housing Authority [18, pp. 13 - 14; 111, pp. 1 - 2]. Based on documentation provided by the Executive Director of Attleboro Housing Authority, 75 residents occupy the residence at this property, which is located within 200 feet of samples P - 0 5 - SS - 01, P - 05 - SS - 04 , and P - 05 - SS - 06 [ 92, pp. 1 - 2, 5 - 6; 111, pp. 1 - 2]. The population of the one residence located at the property designated as “P - 17” (with sample P - 17 - SS 07A), identified on the City of Attleboro Tax Assessor’s Map No. 49, as Lot No. 94, was obtained by interviews conducted by WESTON START personnel as part of the EPA SR , and confirmed by MassDEP [18, pp. 13 - 14, 18; 110, pp. 1 - 2]. Based on information obtained by interviews conducted by WESTON START and MassDEP personnel, one resident occ upies the residence at this property, which is located within 200 feet of sample P - 17 - SS - 07A [18, p. 18; 92, pp. 1 - 2, 6; 110, pp. 1 - 2]. The population of the one residence located at the property designated as “P - 18” (with samples P - 18 - SS 07, P - 18 - SS - 08 a nd P - 18 - SS - 09), identified on the City of Attleboro Tax Assessor’s Map No. 49, as Lot No. 96, was obtained by interviews conducted by WESTON START personnel as part of the EPA SR , and confirmed by MassDEP [18, pp. 13 - 14, 18; 110, pp. 1 - 2]. Based on informa tion obtained by interviews conducted by WESTON START and MassDEP personnel, two residents occupy the residence at this property, which is located within 200 feet of samples P - 18 - SS - 07, P - 18 - SS - 08, and P - 18 - SS - 09 [18, p. 18; 92, pp. 1 - 2, 7; 110, pp. 1 - 2]. Area C: The population of the one residence located at the property designated as “P - 21” (with samples P - 21 - SS 03 and P - 21 - SS - 04), identified on the City of Attleboro Tax Assessor’s Map No. 49, as Lot No. 125, was obtained by interviews conducted by a Ma ssDEP representative [18, pp. 13 - 14; 110, pp. 1 - 2]. Based on documentation provided by MassDEP, two residents occupy the residence at this property, which is located within 200 feet of samples P - 21 - SS - 03 and P - 21 - SS - 04 [ 92, pp. 1 - 2, 8; 110, pp. 1 - 2]. The population of the two adjoined residences located at the property designated as “P - 22” (with sample P - 22 - SS - 07), identified on the City of Attleboro Tax Assessor’s Map No. 49, as Lot No. 126, was obtained by interviews conducted by a MassDEP representative [18, pp. 13 - 14; 110, pp. 1 - 2]. Based on documentation provided by MassDEP, four residents occupy the two residences at this property, which is located within 200 feet of sample P - 22 - SS - 07 [110, pp. 1 - 2]. However, based on interviews conducted by WESTON ST ART personnel as part of the EPA SR , six residents were determined to occupy the residences at property P - 22 (Map No. 49, Lot No. 126) [18, pp. 13 - 14, 19]. For the purposes of this HRS documentation record, four residents are presented as an estimated popu lation residing on property P - 22 (Map No. 49, Lot No. 126), based on interviews conducted by MassDEP [18, pp. 13 - 14; 92, pp. 1 - 2, 8; 110, pp. 1 - 2].Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 145 HRS Documentation Record MAD001197755 5 September 2012 Based on field observations made by WESTON START personnel, two condominium units within 200 feet of sample P - 23 - SS - 02, and four condominium units within 200 feet of sample P - 23 - SS - 06 , were identified as inhabited [112, pp.1 - 2]. No information regarding the exact number of residents living within these condominium units was available; therefore, one resident pe r occupied condominium unit is assumed for the property designated as “P - 23” . Table 8 0 – Level I Concentration Factor Area Letter Sample ID * Number of Residences Total No. of Residents References A P - 04 - SS - 06 

### 1 2 18, pp. 13 - 14; ; 110, pp. 1 - 2 A P - 07 - SS - 02/ P - 30 - SS - 02 

### 1 2 18, pp. 13 - 14; 110, pp. 1 - 2 A P - 09 - SS - 07 

### 1 4 18, pp. 13 - 14, 17 - 18; 110, pp. 1 - 2 B P - 05 - SS - 01 

### 1 75 18, pp. 13 - 14, 22; 111, pp. 1 - 2 P - 05 - SS - 04 P - 05 - SS - 06 B P - 17 - SS - 07A 

### 1 1 18, pp. 13 - 14, 18; 110, pp. 1 - 2 B P - 18 - SS - 07 

### 1 2 18, pp. 13 - 14, 18; 110, pp. 1 - 2 P - 18 - SS - 08 P - 18 - SS - 09 C P - 21 - SS - 03 1 2 18, pp. 13 - 14; 110, pp. 1 - 2 P - 21 - SS - 04 C P - 22 - SS - 07 2 4 18, pp. 13 - 14, 20; 110, pp. 1 - 2 C P - 23 - SS - 02 2 2 18, pp. 13 - 14, 21; 110, pp. 1 - 2; 112, pp.1 - 2 C P - 23 - SS - 06 4 4 18, pp. 13 - 14, 21; 28, p. 82; 112, pp.1 - 2 NA = Not Applicable. * = Property designations ( e.g. , “P - 01”, “P - 02”, etc. ) were assigned during the 2012 EPA SR , and are associated with the corresponding identifiers for soil samples collected from each property ( e.g. , P - 01 - SS - ##, P - 02 - SS - ##, etc. ) [18, pp. 13 - 14]. The corresponding residential addresses associated with each property designation are provided in available reference documentation [18, p. 13]. Sum of individuals subject to Level I concentrations: 98 Sum of individuals subject to Level I concentrations x 10: 980Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 146 HRS Documentation Record MAD001197755 5 September 2012 Level I Concentrations Factor Value : 980 5.1.3.2.2 Level II Concentrations NS = Not Scored. Level II Resident Population Targets NS = Not Scored. Sum of individuals subject to Level II concentrations: 0 Level II Concentrations Factor Value: 0 5.1.3.3 Workers No workers were identified for the propert ies encompassed by Areas A, B, and C . Table 8 1 – Workers Area Letter Number of Workers References NS NS = Not Scored. Total workers: 0 Workers Factor Value (Ref. 1, Table 5 - 4): 0 5.1.3.4 Resources Description of Resource(s): None Available information does not document that any resources , as defined under HRS Section 5.1.3.4 , are present within the area s of observe d contamination (Areas A, B, and C). Therefore, a Resource Value of 0 is assigned [1, p. 51647, Section 5.1.3.4]. Resources Factor Value: 0Soil Exposure Resident Population Threat

Walton & Lonsbury Inc. 147 HRS Documentation Record MAD001197755 5 September 2012 5.1.3.5 Terrestrial Sensitive Environments Available information does not document that any terrestrial sensitive environments , as defined by HRS Section 5. 1.3.5, Table 5 - 5, are located within Areas A, B, and C [1, pp. 51647, 51648 ]. Table 8 2 – Terrestrial Sensitive Environments Factor Area Letter Terrestrial Sensitive Environment Assigned Value (Ref. 1, Table 5 - 5) References A None 0 1, pp. 51647, 51648 B None 0 1, pp. 51647, 51648 C None 0 1, pp. 51647, 51648 The Terrestrial Sensitive Environments Value is assigned by multiplying the Residential Population Likelihood of Exposure Value (550), the Waste Characteristics Value (10), and the Terrestrial Sensitive Environments rating Value (0), and dividing by 82,500 [1, p. 51647, Section 5.1.3.5]. Likelihood of exposure fac tor category value (LE): 550 Waste characteristics factor category value (WC): 10 Terrestrial sensitive environments value (ES): 0 Product (LE x WC x ES): 0 (LE x WC x ES)/82,500 (EC): 0 If EC is >60, Value of EC: Not Applicable Because the Terrestrial Sensitive Environm ents Value is less than 60, a Terrestrial Sensitive Environments Factor Value of 0 is assigned [1, p. 51648]. Terrestrial Sensit ive Environments Factor Value: 0 5.2 NEARBY POPULATION THREAT Due to the values obtained based on the Resi dent Population Threat, the Nearby Population Threat was not evaluated as it would not contribute significantly to the overall site score.