Revisions to Leeds Metal HRS Documentation Record July 6, 20 12

1. On page 1, the Ground W ater P athway score was change d from 100.00 to 64.512 , and the HRS SITE SCORE was changed from 50.00 to 32.25.

2. On page 2, the following changes were made:

• On line 1, Groun d Water Migration Pathway Score (S gw ), the “S” value was changed from 100.00 to 64.512; the “S 2 ” value change d from 10,000 to 4,161.798.

• On line 5, Total of S 2 gw + S 2

sw + +S 2

s = S 2

a , the “S 2 ” value was changed from 10,000 to 4,161.798.

• On line 6, HRS Site Score, the “S 2 ” value was changed from 50.00 to 32.25.

3. On page 3, t he following changes were made:

• On line 4, Toxicity/Mobility, the “Value Assigned” was changed from 10,000 to 1,000.

• On line 6, Waste Characteristics, the “Value Assigned” was changed from 100 to 56.

• On line 8a, Level I Concentrations, the “Value Assigned” was changed from 170 to 50.

• On line 8b, Level II Concentrations, the “Value Assigned” was changed from NS to 12.

• On line 8c, Potential Contamination, the “Value Assigned” was changed from NS to 60.8.

• On line 8d, Population (lines 8a + 8b + 8c), the “Value Assigned” was changed from 170 to 122.8.

• On line 11, Targets (lines 7 + 8d + 9 + 10), the “Value Assigned” was changed from 220 to 172.8. On line 12, Aquifer Score [(lines 3 x 6 x 11)/82,500], the “Value Assigned” was changed from 100.00 to 64.512. On line 13, Pathway Score (S gw ), the “Value Assigned” was changed from 100 to 64.512.

n page 13, Ref. No. [3] was removed and replaced with “Reference Reserved.”

ew r eferences [176 ] through [1 80] were added on new page 25a.

n section 3.2.1, TOXICITY/MOBILITY , on page 125, the following changes were made: In the first paragraph on the third line, “[2, pp. BI

- 10, BII

- 11; 3, pp. BI

- 1, BII

- 1]” was updated to “[2, pp. BI-1, 3, 8; 176, pp. A-1-2; 177 pp. BI-10-11, A-295-296, 335-336; 178; 179].” In the table, i n the PCE row , the “References” column entry was updated from “2, pp . b I-10” to “177 pp. BI-11, A-335, A-336; 178; 179.” In the table, i n the TCE row , the “Toxicity Factor Value” column entry was updated from 10,000 to 1,000; the “Toxicity/Mobility” column entry was updated from 10,000 to 1,000; and the

“ References” column entry was updated from “ 3. pp. BI -1” to “176pp. A- 1, A

- 2; 177 pp. BI -11; 178; 179.” In the table, i n the Arochlor -1254 ro w , the “References” column entry was updated from “ 2, pp. BI -10” to “177 pp. BI-10, A-295, A- 296; 178; 179 .” In the table, on the Arochlor

- 1260 row, the “References” column entry was updated from “ 2, pp. BI -10” to “177 pp. BI-10, A-295, A- 296; 178; 179 .” In the table, on the Arsenic row, the “References” column entry was c orrected from “ 2, pp. BI -1 ” to “ 2 p BI -1.” •

•

4. O

5. N

6. I

•

•

•

•

•

•Leeds Metal HRS Documentation Record Revisions (7/ 6

/12) 2

• In the table, on the “Chromium” row, the “References” column entry was corrected from “ 2, pp. BI -3” to “2 p BI-3.”

• In the table, on the “Lead” row, the “References” column entry was corrected from “ 2, pp. BI -8 ” to “ 2 p BI -8.”

• In t he paragraph following the table :

― O n line 1, the Toxicity Factor Value was changed from 10,000 to 1,000

.

― On line 2 , the citation “3, pp.BI

- 1” was replaced with the fol lowing citations , “ 176, pp. A -1- 2; 177 pp. BI-11; 178; 179.”

― On line 3, the Toxicity Factor Value was updated from 10,000 to 1,000.

― On line 4, the Toxicity/Mobility Factor Value was updated from 10,000 to 1,000.

• In the final line on page 125, The Toxicity/Mobility Factor Value was updated from 10,000 to 1,000.

7. In section 3.2.3 , WASTE CHARACTERISTICS FACTOR CATEGORY VALUE, on page 126 , the following changes were made :

• In the first paragraph the following changes were made:

― On line 1, the Toxicity Factor Value was updated from 10,000 to 1,000.

― O n line 2 , the Toxicity/Mobility Factor Value was updated from 10,000 to 1,000.

― On line 3, the Toxicity/Mobility Factor Value for the aquifer was updated from 10,000 to 1,000.

― On line 6, “10,000 x 10,000 = 1 x 10 8 ” was updated to “1,000 x 10,000 = 1 x 10 7 .”

• On the first right- justified line following the first paragraph, the Toxicity/Mobility Factor Value: was updated from 10,000 to 1,000.

• On the third right

- justified line, “ Toxicity/ Mobility Factor Value (10,000) × Hazardou s Waste Quantity Factor Value (10,000): 1 × 10 8 ” was updated to “ Toxicity/Mobility Factor Value (1,000) × Hazardous Waste Quantity Factor Value (10,000): 1 × 10 7 .”

• In the second paragraph, on the first line, the Waste Characteristics Product of (1 × 10 8 ) was updated to (1 × 10 7 ); and on the second line, the Waste Characteristics Factor Category Value of 100 was updated to 56.

• On the last line of the section, the Waste Characteristics Factor Category Value was updated from 100 to 56.

8.

• The first line of the section, which was formerly the subheading “ Level I Concentrations

, ” has been removed. (It has been reinserted on page 127 where appropriate.)

• The following t ext that appeared at the end of the first paragraph of the section was deleted : “ PCE was detected at a concentration above the health

- based benchmarks for hazardous substances in drinking water (screening concentration for cancer corresponding to that concentr ation that corresponds to the 10 -6 individual cancer risk for oral exposures) in one drinking water sample, DW

- 12 [1, pp. 51593 (Section 2.5.1 and Section 2.5.2), 51603 (Table 3

- 10); 2, BII -11; 16, pp.22

- 23; 34, p. 25; 46, Table 1 (p. 1 of 3); 74, pp. 1-2].” In s ection 3.3, “TARGETS,” starting on page 126, the following ch an ges were made:Leeds Metal HRS Documentation Record Revisions (7/ 6

/12) 3

• The second paragraph of section 3.3 was split into two paragraphs in the middle of the sixth line; the subhead, Level I Concentrations , was added at this place ; and the phrase “Of the seven drinking water samples presented,” was added to begin the sente nce that now starts the third paragraph.

• In the fourth line of the third paragraph, “ seven drinking water samples ” was updated to “two drinking water samples.”

• In the sixth line of the third paragraph, the following reference citations were added to the list of citations that begins on the fourth line, “ 176, pp. A-1-2; 177 pp. BII-23; 178; 179 .”

• In the former second paragraph, now the third paragraph, the final sentence that begins, “In addition, TCE was detected in two drinking water samples (DW09 and DW -15) at concentrations at or greater than the cancer risk comparison concentration but below the sample adjusted CRQL
, ” was deleted.

• The table in the middle of page 127 showing benchmark information was replaced with an updated table.

• The subsection titled

, Level II Concentrations , was added.

• A paragraph and table were added under the new subsection titled, Level II Concentrations. The content of this paragraph and table reflects the drinking water samples that document Level II concentrations of TCE.

• In se ction 3.3.1 , NEAREST WELL, formerly on page 127, now on page 128, in the first line, the words “and PCE” have been removed ; i n the fourth line, the following new references have been added , “ 176, pp. A-1-2; 177 pp. BII-23; 178; 179.”

9. Withi n the POPULATION section (3.3.2) , in section 3.3.2.2, Level I Concentrations, under the subheading “Level I Population Targets”, the following changes were made:

• In the first line the words “PCE and” have been removed

• Starting in the first line, “seven drinking water supp ly wells” was changed to “two drinking water supply wells.”

• References have been updated throughout the section.

• The table showing aquifer number and population was replaced with an updated table.

• The “Sum of Population Served by Level I Wells” was updated from 17 to 5, and the “Sum of Population Served by Level I Wells x 10” was updated from 170 to 50.

10. Within the POPULATION section (3.3.2) , the content of sections 3.3.2.3, Level II Concentrations, and 3.3.2.4, Potential Contamination , ha s been replaced w ith updated content; pages 129a, 129b and 129c have been added that contain additional c ontent regarding potential contamination and potential population targets.HRS DOCUMENTATION RECORD

Name of Site: Leeds Metal Date Prepared: September 2011

EPA Region: Region I

Street Address of Site*: Off of Blue Rock Road

City, County, State, Zip Code: Leeds, Androscoggin County, Maine, 04263

General Location in the State: Southwestern Maine

Topographic Map: U.S. Geological Survey, Monmouth, Maine 7.5

- minute series Topographical Map. 1979 [7].

Latitude**: 44° 14 ′ 13.5 ′′ North

Longitude**: 70° 04 ′ 48.9 ′′ West

Scores

Air Pathway Ground Water Pathway Soil Exposure Pathway Surface Water Pathway NS 64.512 NS NS

HRS SITE SCORE 32.25

NS = Not Scored

* The street address, coordinates, and contaminant locations presented in this Hazard Ranking System (HRS) documentation record identify the general area th e site is located. They represent one or more locations U.S. Environmental Protection Agency (EPA ) considers 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 national priorities among the known “releases or threaten ed releases” of hazardous substances; thus, the focus is on the release, not precisely delineated boundaries. A site is defined as where a hazardous substance has been “deposited, stored, placed, or othe rwise come to be located.” Generally, HRS scoring and the subsequent listing of a release merely represen t the initial determination that a certain area may need to be addressed under 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 inform ation is developed as to where the contamination has come to be located.

** The geographic coordinates of the site were me asured from its approximate center [4, p. 1]. See Figure 2 for the location of the latitude and longitude measurement point.

Leeds Metal 1 HRS Documentation Record MEN000103584 September 2011S S 2

1. Ground Water Migration Pathway Score (S g w )

2. Surface Water Overland/Flood Migration Component 64.512 4161.798

(from Table 4-1, line 30)

3. Soil Exposure Pathway Score (S s ) NS

--

(from Table 5-1, line 22) 4. Air Migration Pathway Score (S a ) (from Table 6-1, line 12)

2 5. Total of S gw 2 + S sw 2 + S s 2 + S a 6. HRS Site Score Divide the value on line 5 by 4 and take the square root NS

NS --

--

4161.798

32.25 WORKSHEET FOR COMPUTING HRS SITE SCORE

Leeds Metal 2 HRS Documentation Record MEN00010 3 584 September 2011HRS Table 3-1 – Ground Water Migration Pathway Scoresheet

Factor Categories and Factors Maximum Value Value Assigned Likelihood of Release to an Aquifer:

1. Observed Release 550 550
2. Potential to Release:

2a. Containment 10 NS 2b. Net Precipitation 10 NS 2c. Depth to Aquifer 5 NS 2d. Travel Time 35 NS 2e. Potential to Release [lines 2a x (2b + 2c + 2d)] 500 NS
3. Likelihood of Release (higher of lines 1 and 2e) 550 550 Waste Characteristics: 4. Toxicity/Mobility (a) 1,000 5. Hazardous Waste Quantity (a) 10,000 6. Waste Characteristics 100 56 Targets : 7. Nearest Well 50 50 8. Population: 8a. Level I Concentrations (b) 50 8b. Level II Concentrations (b) 12 8c. Potential Contamination (b) 60.8 8d. Population (lines 8a + 8b + 8c) (b) 122.8
9. Resources 5 NS 10. Wellhead Protection Area 20 NS 11. Targets (lines 7 + 8d + 9 + 10) (b) 172.8 Ground Water Migration Score For An Aquifer: 12. Aquifer Score [(lines 3 x 6 x 11)/82,500] (c) 100 64.512 Ground Water Migration Pathway Score:
13. Pathway Score (S gw ), (highest value from line 12 for all aquifers evaluated) c 100 64.512
(a) Maximum value applies to waste characteristics category. (b) Maximum value not applicable. (c) Do not round to nearest integer.

Leeds Metal 3 HRS Documentation Record MEN000103584 September 2011REFERENCES

Ref. No. Description 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 is available from http://www.epa.gov/superfund/sites/ npl/hrsres/index.htm#HRS%20 Rule . 14 December. Excerpt. 32 pages.

[2] U.S. Environmental Protection Agency (EPA). 2004. Superfund Chemical Data Matrix (SCDM). Available from http://www.epa.gov/superfund/sites/npl/hrsres/tools/scdm.htm

. January. Excerpt. 107 pages.

[3] Reference Reserved.

[4] Hornok, G. Weston Solutions, Inc. 2010. Project Note, Leeds Metal, RE: Latitude/Longitude Calculations. TDD No. 09-05-0004. 25 January. 1 page.

[5] U.S. Environmental Protection Agency (EPA). 2011. Comprehensive Environmental Response, Compensation, and Liability Information System (CERCLIS) Superfund Program, Region 1, RE: Leeds Metal. Available from http://cumulis.epa.gov/supercpad/cursites/csitinfo.cfm?id=0103584 . Printout dated 3 March. 2 pages.

[6] Weston Solutions, Inc., Superfund Technical Assessment and Response Team III (START). 2010. Site Assessment Program Site-Specific Q uality Assurance Project Plan for Surface and Subsurface Soil/Source, Groundwater, Drinking Water, and Sediment Sampling , Leeds Metal, Site Inspection, Leeds, Maine. TDD No. 09-05-0004. 26 October. 104 pages.

[7] U.S. Geological Survey (USGS). 1979. Monmouth, Maine (7.5-minute series topographic map). 1 page.

[8] U.S. Geological Survey (USGS). 1966. Wayne, Maine (7.5-minute series topographic map). 1 page.

[9] James W. Sewall Company. 2009. Property Map Number 4, Town of Leeds, Androscoggin County, Maine. 1 April. 1 page.

[10] James W. Sewall Company. 2009. Property Map Number 1, Town of Leeds, Androscoggin County, Maine. 1 April. 1 page.

[11] Weston Solutions, Inc., Superfund Technical Assessment and Response Team III (START). 2011. Final Site Inspection Report for Leeds Metal , Leeds, Maine. TDD No. 09-05-0004. 19 August. 321 pages.

[12] Town of Leeds, Maine. 2010. Property Card for Map Number 4 Lot Number 38. 2 September. 2 pages.

Leeds Metal 13 HRS Documentation Record MEN000103584 September 2011REFERENCES

Ref. No. Description of the Reference

[176] U.S. Environmental Protection Agency (EPA). 2012. Superfund Chemical Data Matrix (SCDM) – Interim Report for Trichloroethylene (TCE), Appendix A. Available from http://www.epa.gov/superfund/sites/npl/hrsres/tools/scdm.htm

. 

### 31 March . 2 pages.

[177] 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. 57 pages.

[178] U.S. Environmental Protection Agency (EPA). 2012 Methodology for Determining Chemical and Physical Properties Factor Valu es and Screening Concentration Benchmarks for Volatile Substances Listed in the U.S. EPA’s Superfund Chemical Data Matrix . Available from. http://www.epa.gov/superfund/sites/npl/hrsres/tools/scdm-update-methodology.pdf

. March. 40 pages.

[179] U.S. Environmental Protection Agency (EPA). 2012. SUBSET of SCDM Volatile Substances and Corresponding Factor Values and Supporting Data. . Available from http://www.epa.gov/superfund/sites/npl/hrsres/t ools/volatile-substances-factor-values.pdf. 31 March. 8 pages.

[180] Hornok, G. and Kelly, J. Weston Solutions, Inc. 2012. Project Note, Re: Summary of methods used to calculate Potential Groundwater Population within 4 Radial Miles of Leeds Metal. 27 June. 40 pages.

Leeds Metal 2 5a HRS Documentation Record MEN000103584 September 2011Ground Water Migration Pathway Leeds Aquifer

3.2 WASTE CHARACTERISTICS

3.2.1 TOXICITY/MOBILITY

The Toxicity Factor Value and the Mobility Fact or Value are assigned to the hazardous substances associated with the sources and rel eases at the site, and are based on the values presented in the Superfund Chemical Data Matrix (SCDM) [2, pp. BI-1, 3, 8; 176, pp. A-1-2; 177 pp. BI-10-11, A-295-296, 335-336; 178; 179].

Hazardous Substance Source No. (and/or Observed Release) Toxicity Factor Value Mobility Factor Value* Does Hazardous Substance Meet Observed Release by Chemical Analysis? (Y/N) Toxicity/ Mobility (Ref. 1, Table 3-9) References

PCE 4,5 100 1 Y 100 177 pp. BI-11
, A335, A-336; 178; 179

TCE Degradation Product of PCE 1,000 1 Y 1,000 176 pp. A-1, A-2; 177 pp. BI-11; 178; 179

Aroclor1254 1, 2, 3, 4, 5 10,000 0.0001 N 1 177 pp. BI-10
, A295, A-296; 178; 179

Aroclor1260 1, 2, 3, 4, 5 10,000 0.0001 N 1 177 pp. BI-10
, A295, A-296; 178; 179
Arsenic 1, 4 10,000 0.01 N 100 2 p

. BI-1
Chromium 1, 2, 4, 5 10,000 0.01 N 100 2 p

. BI-3
Lead 1, 2, 3, 4, 5 10,000 0.01 N 100 2 p

. BI-8 *Per the HRS, any hazardous substance that meet s the criteria for an observed release by chemical analysis to one or more aquifers underlying the s ources at the site, regardless of the aquifer being evaluated, assign a mobility factor va lue of 1 (Ref. 1, Section 3.2.1.2).

The observed release substance, TCE, is assigned a Toxi city Factor Value of 1,000 and a Mobility Factor Value of 1.0 [1, p. 51601 (Sections 3.2.1.1 and 3.2.1.2) ; 176, pp. A-1-2; 177 pp. BI-11; 178; 179 ]. From HRS Table 3-9, a Toxicity Factor Value of 1,000 an d Mobility Factor Value of 1.0 for TCE are assigned a Toxicity/Mobility Factor Value of 1,000 [1, 51602 (Table 3-9)].

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

Leeds Metal 125 HRS Documentation Record MEN000103584 September 2011Ground Water Migration Pathway Leeds Aquifer

3.2.2 HAZARDOUS WASTE QUANTITY

Source No. Source Type Source Hazardous Waste Quantity

1 Pile 2,565.2

2 Pile 8,226.4
3 Pile 690.8

4 Pile 4,512.0

5 Contaminated Soil 5.6

Sum of Values: 16,000.0

Based on HRS Section 2.4.2.2, if the Hazardous Cons tituent Quantity is not adequately determined for one or more sources, and if any target for the groun d 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, as the Hazardous Waste Quantity Factor Value for that pathway [1, pp. 51591 (Table 2-6), 51592 (Section 2.4.2.2)].

Hazardous Waste Quantity Factor Value (Ref. 1, Table 2-6): 10,000

3.2.3 WASTE CHARACTERISTICS FACTOR CATEGORY VALUE

The Toxicity Factor Value (1,000) and the Mobility Factor Value (1.0) for TCE are multiplied in order to determine the Toxicity/Mobility Factor Value (1 ,000) [1, pp. 51590 (Section 2.4.2), 51602 (Section 3.2.1.3, Table 3-9)]. The Toxicity/Mobility Factor Value for the aquifer (1,000) is multiplied by the Hazardous Waste Quantity Factor Value for the aquifer (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), 51602 (Section 3.2.3)]. 1,000 × 10,000 = 1 × 10 7

. Toxicity/Mobility Factor Value: 1,000 Hazardous Waste Quantity Factor Value: 10,000

Toxicity/Mobility Factor Value (1,000) × Hazardous Waste Quantity Factor Value (10,000): 1 × 10 7

From HRS Table 2-7, the Waste Characteristics Product (1 × 10 7 ) is assigned a Waste Characteristics Factor Category Value of 56 [1, pp. 51592 (Section 2.4.3.1), 51602 (Section 3.2.3)].

Waste Characteristics Factor Category Value (Ref. 1, Table 2-7): 56

3.3 TARGETS

Of the seven drinking water samples presented, PCE was detected at a maximum concentration of 3.9 μg/L in drinking water sample DW-12 [16, pp. 22-23; 34, pp. 25; 46, Table 1 (p. 1 of 3); 74, pp. 1-2]. PCE was detected in five (DW-12, DW-13, DW-18, DW-23, and DW-24) of the seven selected drinking water samples at concentrations greater than or e qual to the background sample concentration (DW-02, PCE concentration of 0.5 U μg/L) [14, pp. 23-25, 44- 45; 15, pp. 16-17; 16, pp. 7-10, 22-23; 34, pp. 8, 12, 15, 22-23, 25; 45, Table 1 (pp. 1-2 of 3); 46, Table 1 ( pp. 1-2 of 3); 47, Table 1 (p. 1 of 3); 74, pp. 1-2].

Of the seven drinking water samples presented, TC E was detected at a maximum concentration of 18

Leeds Metal 126 HRS Documentation Record MEN000103584 September 2011Ground Water Migration Pathway Leeds Aquifer

μg/L in drinking water sample DW-12 [16, pp. 22-23; 34, pp. 25; 46, Table 1 (p. 1 of 3); 74, pp. 1-2]. TCE was detected in each of the seven selected ground water samples, at concentrations greater than or equal to the relevant background sample concentrati on (DW-02, TCE concentration of 0.5 U μg/L) [14, pp. 23-25, 35-38, 44-45; 15, pp. 16-17; 16, pp. 7-10, 22-23; 34, pp. 8, 10-12, 15, 22-23, 25; 45, Table 1 (pp. 1-2 of 3); 46, Table 1 (pp. 1-2 of 3); 47, Table 1 (p. 1 of 3); 74, pp. 1-2].

Level I Concentrations

Of the seven drinking water samples presented, TCE w as detected at a concentration above the healthbased benchmarks for hazardous substances in dri nking water (screening concentration for cancer corresponding to that concentration that corresponds to the 10 -6 individual cancer risk for oral exposures) in two drinking water samples (DW-12 and DW-24) [1, pp. 51593 (Section 2.5.1 and Section 2.5.2), 51603 (Table 3-10); 14, pp. 44-45; 16, pp. 22-23; 34, pp. 12, 25; 45, Table 1 (pp. 2 of 3); 46, Table 1 (pp. 1 of 3); 74, pp. 1-2; 176, pp. A-1-2; 177 pp. BII-23; 178; 179].

Sample ID Hazardous Substance Hazardous Substance Concentration (μg/L) Benchmark Concentration (μg/L) Benchmark References for Benchmark

DW-12 TCE 18 1.0 Cancer Risk 176, pp. A-1-2; 177 pp. BII-23. A-1, A-2; 178; 179

DW-24 TCE 1.5 1.0 Cancer Risk 176, pp. A-1-2; 177 pp. BII-23; 178; 179

TCE = Trichloroethene. μg/L = Micrograms per Liter.

Level II Concentrations

Of the seven drinking water samples presented, TCE w as detected at a concentration greater than or equal to the relevant background sample concentration but below the health-based benchmarks for hazardous substances in drinking water (screening concentration for cancer corresponding to that concentration that corresponds to the 10 -6 individual cancer risk for oral exposures) in five drinking water samples (DW-13, DW-16, DW-18, DW-23, and DW-25) [1, pp. 51593 (Section 2.5.1 and Section 2.5.2), 51603 (Table 3­ 10); 14, pp. 23-25, 35-38, 44-45; 15, pp. 16-17; 16, pp . 9-10, 22-23; 34, pp. 8, 10-12, 15, 22-23, 25; 45, Table 1 (pp. 1-2 of 3); 46, Table 1 (pp. 1-2 of 3); 47 , Table 1 (p. 1 of 3); 74, pp. 1-2; 176, pp. A-1-2; 177 pp. BII-23; 178; 179].

Sample ID Hazardous Substance Hazardous Substance Concentration (μg/L) Benchmark Concentration (μg/L) Benchmark References for Benchmark

DW-13 TCE 0.96 1.0 Cancer Risk 176, pp. A-1-2; 177 pp. BII-23; 178; 179

DW-16 TCE 0.63 1.0 Cancer Risk 176, pp. A-1-2; 177 pp. BII-23; 178; 179

Leeds Metal 127 HRS Documentation Record MEN000103584 September 2011Ground Water Migration Pathway Leeds Aquifer

DW-18 TCE 0.52 1.0 Cancer Risk 176, pp. A-1-2; 177 pp. BII-23; 178; 179

DW-23 TCE 0.91 1.0 Cancer Risk 176, pp. A-1-2; 177 pp. BII-23; 178; 179

DW-25 TCE 0.65 1.0 Cancer Risk 176, pp. A-1-2; 177 pp. BII-23; 178; 179

TCE = Trichloroethene. μg/L = Micrograms per Liter.

3.3.1 NEAREST WELL

Based on TCE analytical results of drinking water samples, a release to the supply aquifer has been documented, and Level I concentra tions confirmed [1, pp. 51593 (Secti on 2.5.1 and Section 2.5.2), 51603 (Table 3-10); 14, pp. 44-45; 16, pp. 22-23; 34, pp. 12, 25; 45, Table 1 (pp. 2 of 3); 46, Table 1 (pp. 1 of 3); 74, pp. 1-2; 176, pp. A-1-2; 177 pp. BII-23; 178; 179]. As a drinking water supply well is subject to Level I concentrations, a Nearest Well Factor Value of 50 is assigned [1 , pp. 51602-51603 (Section 3.3.1)]. The closest drinking water supply well contai ning Level I concentrations of the target compounds is located 0.149 miles southwest of Source No. 4 [105, pp. 1-2, Figure 1].

Well ID: DW-12 Level of Contamination (I, II, or potential): I If potential contamination, distance from source in miles:

Nearest Well Factor Value (Ref. 1, Table 3-11): 50 3.3.2 POPULATION

3.3.2.1 Level of Contamination

3.3.2.2 Level I Concentrations

Level I Population Targets

Based on TCE analytical results of drinking water sa mples, a release to two drinking water supply wells has been documented, and Level I concentrations confirmed [1, pp. 51593 (Section 2.5.1 and Section 2.5.2), 51603 (Table 3-10); 14, pp. 44-45; 16, pp. 22-23; 34, pp.12, 25; 45, Table 1 (pp. 2 of 3); 46, Table 1 (pp. 1 of 3); 74, pp. 1-2; 176, pp. A-1-2; 177 pp. BII-23; 178; 179]. Information provided by the residents served by the drinking water supply wells indicate that a total of five Level I Actual Contamination Targets have been documented [1, pp. 51593 (Section 2.5.1 and Section 2.5.2), 51603 (Table 3-10); 14, pp. 44-45; 16, pp. 22-23; 34, pp.12, 25; 45, Table 1 (pp. 2 of 3); 46, Table 1 (pp. 1 of 3); 74, pp. 1-2; ; 117; 129; 176, pp. A-1-2; 177 pp. BII-23; 178; 179].

Level I Well Aquifer No. Population References

DW-12 1 3 117; 16, p. 22

DW-24 1 2 129; 14, p. 44

Sum of Population Served by Level I Wells: 5

Leeds Metal 128 HRS Documentation Record MEN000103584 September 2011Ground Water Migration Pathway Leeds Aquifer

Sum of Population Served by Level I Wells x 10: 50

Level I Concentrations Factor Value: 50 [1, p. 51603, Section 3.3.2.2] 3.3.2.3 Level II Concentrations

Level II Population Targets

Based on TCE analytical results of drinking water samples, a release to five drinking water supply wells has been documented, and Level II concentrations confirmed [1, pp. 51593 (Section 2.5.1 and Section 2.5.2), 51603 (Table 3-10); 14, pp. 23-25, 35-38, 15, pp. 16-17; 16, pp. 9-10; 34, pp. 8, 10-11, 15, 22-23; 45, Table 1 (pp. 1-2 of 3); 46, Table 1 (pp. 1-2 of 3); 47, Table 1 (p. 1 of 3); 74, pp. 1-2; 176, pp. A-1-2; 177 pp. BII-23; 178; 179 ]. Informa tion provided by the residents served by the drinking water supply wells indicate that a total of 12 Level II Actual Contamination Targets have been documented [1, pp. 51593 (Section 2.5.1 and Section 2.5.2), 51603 (Table 3-10); 14, pp. 23-25, 35-38; 15, pp. 16-17; 16, pp. 9-10; 34, pp. 8, 10-11, 15, 22-23; 45, Table 1 (pp. 1-2 of 3); 46, Table 1 (pp. 1-2 of 3); 47, Table 1 (p. 1 of 3); 74, pp. 1-2;; 114; 119; 121, p. 2; 122; 124, p. 4; 127; 131; 176, pp. A-1-2; 177 pp. BII-23; 178; 179].

Level II Well Aquifer No. Population References

DW-13 1 2 119; 14, p. 23

DW-16 1 2 121, p. 2; 122; 14, p. 37

DW-18 1 2 124, p. 4; 15, pp. 16-17

DW-23 1 3 127; 16, p. 9

DW-25 1 3 131; 14, pp. 35-36

Sum of Population Served by Level II Wells: 12

Level II Concentrations Factor Value: 12 [1, p. 51603, Section 3.3.2.3]

3.3.2.4 Potential Contamination

Potential Population Targets

Potential Population Targets were evaluated as part of this HRS Documentation Record to determine the number of people served by drinking water from points of withdrawal subject to potential contamination. This calculation does not include those people alrea dy counted under Level I and Level II concentration factors.

As noted previously in Section 3.0.1 of this HRS Documentation Record, there are no physical barriers to ground water flow, such as mountains or large rivers, wh ich have been identified within a 4-mile radius of the Leeds Metal property; subsurface investigations to date have not identifie d any continuous aquitards in the vicinity of the Leeds Metal property; and the fine-to-coarse sand overburden deposits and moderately permeable fracture metamorphic bedr ock do not demonstrate any significantly lower hydraulic conductivity layers that separate aquifers th roughout a 2-mile radius of the site sources, thus characterizing hydrogeology beneath the site as by a single aquifer consisting of the on-site shallow and deep glacial overburden aquifer and the hydraulical ly connected underlying meta-sedimentary bedrock

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aquifer. Therefore, an aquifer interconnection occurs within 2 miles of the sources at the site and the combined aquifer constitutes the aquifer being evaluate d that is used for scoring the site [1, p. 51595 (Section 3.0.1.2.1)]. For the purposes of this eval uation, the entire population served by drinking water from points of withdrawal within 4-radial miles of the site are eligible for evaluation as potential population targets [1, p. 51595, Section 3.0.1.1].

The calculation of Potential Population Targets was evaluated as part of this HRS Documentation Record utilizing two separate techniques. Method 1 utilizedthe 1990 and 2000 census data to estima te the populations relying upon both priv ate and public ground water supplies presented in the SI report (Reference 11) [11, pp. 112-115; 180]. To estim ate the population served by private ground water supplies, a comparison was made between the 1990 a nd 2000 census data to determine the change (net increase) in population between the two census periods. This calculated proportional change in population was then applied to a subset of the 1990 census da ta (population relying on private drinking water supply wells) to estimate the number of persons relying u pon private water supplies in 2000 [11, pp. 112-115; 180]. Method 2 utilized the most recent census data (2010), which became available after completion of the SI report (Reference 11), and discussions with local personnel knowledgeable of the public and private ground water resource within 4-radial mil es of the site. These discussions with local personnel were used to validate the drinking water suppl y of the entire population presented in the 2010 census within 4-radial miles of the site [11, pp. 112-115; 180]. Potential Population Targets calculation determined through the two methods (Method 1 and Method 2) confirms that there are no significant impact to the Distance-Weighted Population Value and, therefore, no significant impact to the Potential Contamination Factor Value or the overall site sco re. This HRS Documentation Record report s the method resulting in the minimal Potential Population Targets for d etermining the Potential Contamination Factor Value. Furthermore, the listing decision rema ins the same using the Method 1 data utilized at proposal or using the newer 2010 census data, reflecti ng current site conditions; conversely the new data confirms the listing decision [11, pp. 112-115; 180]

Method 1 utilized the 1990 and 2000 census data to cal culate a percent change in the total population within 4-radial miles of the Leeds Metal Site. This calculated proportional change was then applied to the population by radius for the private wells subset of the 1990 census data within each distance ring. The resulting population utilizing private drinking water s upply wells within each radial ring, represented the same proportional increase as the total population from 1990 to 2000 [11, pp. 112-11 5; 180]. In addition, the population served by drinking water from public water supply wells within a 4-mile radius of the Leeds Metal property was determined through informa tion in the ME Drinking Water Program database and summarized in the Leeds Metal SI [11, pp. 112-115; 180].

Method 2 utilized the most recent census data (2010), which became available after completion of the SI report (Reference 11), and discussions with local pe rsonnel knowledgeable of the public and private ground water resource within 4-radial miles of the site. The discussions with local personnel were used to validate the drinking water supply of the entire popu lation presented in the 2010 census within 4-radial miles of the site [11, pp. 112-115; 180]. The 2010 census data (supplied by EPA) was utilized to determine the total population within each distance ring. Discussions with official s, for the towns located within 4-radial miles of the site, were conducted to establish the sources utilized for drinking water supplies located within each of the towns. Public water supply information from the Maine Drinking Water Program database was utilized to determine the supply type, location, and population served by each public supply source located within 4-radial miles of the site. Further discussion with Maine Drinking Water Program, Town, and public water supply system representatives confirmed the data presented in public water supply system database, al ong with activity status, source, location of the withdrawal point, population served, and distribution area (as needed) within each distance ring within a 4-mile radius of the Leeds Metal property. This information was used to estimate the populations currently relying upon private and public ground water supplies within each distance ring within a 4-mile

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radius of the Leeds Metal site [180].

The following table presents the comparison of the Potential Population Targets within a 4-mile radius of the Leeds Metal property utilizing the two methods and the resulting Distance-Weighted Population Value for each method.

Distance Category Method 1 Potential Population

[11, 180] Method 1 Distance-Weighted Population Value (Ref. 1, Table 3-12) Method 2 Potential Population [180] Method 2 DistanceWeighted Population Value (Ref. 1, Table 3-12)

0 to 1/4 mile 21* 17 53* 53

>1/4 to 1/2 mile 169* 102 137* 102

>1/2 to 1 mile 184 52 300 52

>1 to 2 miles 574 94 856 94

>2 to 3 miles 2,921** 212 1,340 212

>3 to 4 miles 1,832 131 2,343 131

Total 5,701 608 5,046 644

* A total of nine Level I and/or Le vel II Population Targets have been accounted for within 1⁄4 mile of the Leeds Metal site, and eight Level I and/or Level II Population Targets have been accounted for greater then 1⁄4 mile to 1⁄2 mile of the site [ 1, pp. 51593 (Section 2.5.1 and Section 2.5.2), 51603 (Table 3-10); 11, pp. 112-115; 14, pp. 23-25, 35-38, 44-45; 15, pp. 16-17; 16, pp. 9-10, 22-23; 34, pp. 8, 10-12, 15, 22-23, 25; 45, Table 1 (pp. 1-2 of 3); 46, Table 1 (pp. 1-2 of 3); 47, Table 1 (p. 1 of 3); 74, pp. 1-2].; 97, p. 12; 117; 119; 121, p. 2; 124, p. 4; 127; 129; 131; 180].

** Note that an error has occurred in the 2011 SI p opulation value calculation due to triple counting of one publi c ground water supply (Monmouth Water Asso ciation) system’s population (the actual value for this ring is 1,835 people). However due to the ra nge in the HRS Population Served By Wells Within Distance Categories, no change occurs in the Distan ce-Weighted Population Value [11, pp. 112-115; 180]

This HRS Documentation Record reports the met hod resulting in the minimal Potential Population Targets for d etermining the Potential Contamination Factor Value [1, Table 3-12; 11, pp. 112-115; 180 ]. The listing decision will remain the same using the Me thod 1 data utilized at proposal or using the newer 2010 census data, reflecting current s ite conditions; conversely the new da ta confirms the listing decision.

Distance Category Population References Distance-Weighted Population Value (Ref. 1, Table 3-12)

0 to 1/4 mile 21* 11, pp. 112-115; 180 17

>1/4 to 1/2 mile 169* 11, pp. 112-115; 180 102

>1/2 to 1 mile 184 11, pp. 112-115; 180 52

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Distance Category Population References Distance-Weighted Population Value (Ref. 1, Table 3-12)

>1 to 2 miles 574 11, pp. 112-115; 180 94

>2 to 3 miles 2,921 ** 11, pp . 112-115; 180 212

>3 to 4 miles 1,832 11, p p. 112-115; 180 131

* A total of nine Level I and/or Le vel II Population Targets have been accounted for within 1⁄4 mile of the Leeds Metal site, and eight Level I and/or Level II Population Targets have been accounted for greater then 1⁄4 mile to 1⁄2 mile of the site [ 1, pp. 51593 (Section 2.5.1 and Section 2.5.2), 51603 (Table 3-10); 11, pp. 112-115; 14, pp. 23-25, 35-38, 44-45; 15, pp. 16-17; 16, pp. 9-10, 22-23; 34, pp. 8, 10-12, 15, 22-23, 25; 45, Table 1 (pp. 1-2 of 3); 46, Table 1 (pp. 1-2 of 3); 47, Table 1 (p. 1 of 3); 74, pp. 1-2].; 97, p. 12; 117; 119; 121, p. 2; 124, p. 4; 127; 129; 131; 180].

** Note that an error has occurred in the 2011 SI p opulation value calculation due to triple counting of one publi c ground water supply (Monmouth Water Asso ciation) system’s population (the actual value for this ring is 1,835 people), however due to the ra nge in the HRS Populatio n Served By Wells Within Distance Categories, no change occurs in the Distance-Weighted Population Value. [ 11, pp. 112-115; 180 ]

Calculations:

Sum of Distance-Weighted Population Values: 608 Sum of Distance-Weighted Population Values/10: 60.8

Potential Contamination Factor Value: 60.8 (1, p. 51603-51604, Section 3.3.2.4)

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3.3.3 RESOURCES

No Resources were evaluated as part of this HRS Documentation Record.

Well ID Aquifer No. Resource Use References

Resources Factor Value: Not Scored

3.3.4 WELLHEAD PROTECTION AREA

No Wellhead Protection Areas were evaluated as part of this HRS Documentation Record.

Area Use References Value

Wellhead Protection Area Factor Value: Not Scored

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