HRS DOCUMENTATION RECORD COVER SHEET

Name of Site: PCE/TCE Northeast Contamination

EPA ID No.: NEN000706105

Contact Persons

EPA Contact : Michelle Quick, EPA Region 7 NPL Coordinator Brian Mitchell, EPA Region 7 Nebraska State Coordinator U.S. Environmental Protection Agency, Region 7 11201 Renner Boulevard Lenexa, Kansas 66219 (913) 551-7335

Site Investigation: US EPA Region 7 Nebraska Department of Environmental Quality (NDEQ)

Documentation Record: Kumud Pyakuryal, Tetra Tech, Inc.

Pathways, Components, or Threats Not Scored
The surface water, soil exposure and air pathways were not scored because evaluation of these pathways would not affect the NPL listing decision.1 HRS DOCUMENTATION RECORD

Name of Site: PCE/TCE Northeast Contamination EPA Region: 7 Date Prepared: Dec ember 2013 Street Address of Site*: 522 W 26th Street, York, Nebraska 68467 (near the intersection of 26 th Street and N. Division Street)
City, County, State: York, York County, Nebraska 68467 General Location in the State: The site encompasses portions of Sections 25 and 36 of Township 11 North, Range 3 West; Sections 29, 30, 31, and 32 of Township 11 North, Range 2 West; Sections 5 and 6, Township 10 North, Range 2 West; and Section 1 of Township 10 North, Range 3 West as depicted on the 7.5- minute topographic quadrangle maps for York North (U.S. Geological Survey [USGS] 1969a, photorevised 1980) and York South (USGS 1969b) (Figure 1; Ref. 3, pp. 1-2)
Topographic Map: The site is located in York, Nebraska, in the southeastern portion of the state, about 50 miles west of Lincoln, Nebraska. The location of the site is shown on the York North and York South, Quadrangle, U.S.G.S. Survey, 7.5-Minute Series Topographic Maps (Ref. 3, pp. 1-2 ).
Latitude*: 40o 53’ 19.09” North (Ref. 3, p. 1) (see Figure 1)
Longitude*: 97o 36’ 01.30” West (Ref. 3, p. 1) (see Figure 1)
The latitude and longitude listed above specify the approximate location of Source 1 (Kroy Industries Building 1). Figure 1 shows the site location.

Scores Ground Water Migration Pathway 100.00 Surface Water Migration Pathway Not Scored Soil Exposure Pathway Not Scored Air Migration Pathway Not Scored HRS SITE SCORE 50.00

Note:

* The street address, coordinates, and contaminant locations presented in this HRS documentation record identify the general area the site is located. They represent one or more locations EPA considers to be part of the site based on the screening information EPA used to evaluate the site for NPL listing. EPA lists national priorities among the known "releases or threatened releases" of hazardous substances; thus, the focus is on the release, not precisely delineated boundaries. A site is defined as where a hazardous substance has been "deposited, stored, disposed, or placed, or has otherwise come to be located." Generally, HRS scoring and the subsequent listing of a release merely represent the initial determination that a certain area may need to be addressed under CERCLA. Accordingly, 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.2

.
WORKSHEET FOR COMPUTING HRS SITE SCORE

S 2 S 1. Ground Water Migration Pathway Score (from Table 3

- 1, line 13) (S gw ) 100 .00 10,000

2a. Surface Water Overland/Flood Migration Component (from Table 4

- 1, line 30) Not Scored
2b. Ground Water to Surface Water (from Table 4

- 25, li ne 28) Migration Component Not Scored
2c. Surface Water Migration Pathway Score (S sw ) Enter the larger of lines 2a and 2b as the pathway score. Not Scored
3. Soil Exposure Pathway Score (S s ) (from Table 5

- 1, line 22) Not Scored
4. Air Migration Pathway Score (S a ) (from Table 6

- 1, line 12) Not Scored
5. 2 Total of S gw 2 + S sw 2 + S s 2 + S a 10,000
6. HRS Site Score Divide the value on line 5 by 4 and take the square root 50.003 TABLE 3-1

 GROUND WATER MIGRATION PATHWAY SCORESHEET

Factor Categories and Factors Maximu m Value Value Assigned Likelihood of Release to an Aquifer: 1. Observed Release: 550 550 2. Potential to Release: 2a. Containment 10 Not Scored 2b. Net Precipitation 10 Not Scored 2c. Depth to Aquifer 5 Not Scored 2d. Travel Time 35 Not Scored 2e. Potential to Release [lines 2a x (2b + 2c + 2d)] 500 Not Scored 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 100 6. Waste Characteristics 100 18 Tar gets: 7. Nearest Well 50 50 8. Population: 8a. Level I Concentrations b 6,125.50 8b. Level II Concentrations b Not Scored 8c. Potential Contamination b 191.1 8d. Population (lines 8a + 8b + 8c) b 6,316.6 9. Resources 5 5 10. Wellhead Protection Area 20 20 11. Targets (lines 7 + 8d + 9 + 10) b 6,391.6 GROUND WATER MIGRATION SOURCE FOR AN AQUIFER 12. Aquifer Source [(lines 3 x 6 x 11)/82,500] c 100 100 .00 GROUND WATER MIGRATION PATHWAY SCORE 13. Pathway Score (S gw ), (highest value from line 12 for all aquifers evaluated) c 100 100 .00

Notes:

a Maximum value applies to waste characteristics category b Maximum value not applicable

c Do not round to nearest integer4 Site Figures5 Site Figures6 Site Figures7 Site Figures8 Site Figures9 References REFERE NCES

Reference Number Description of the Reference
1 U.S. Environmental Protection Agency (EPA). Hazard Ranking System, 40 CFR Part

300, Appendix A, 55 F R 51533. December 14, 1990. Available Online at http://www.epa.gov/superfund/sites/npl/hrsres/index.htm#HRS%20Rule . Excerpt. 1 page. [Note: A complete c opy of the ru l e is available from the Region 7 Docket upon request.]
2 EPA. Superfund Chemical Data Matrix. January 2004 (March 2012 update) . Excerpt. 5

pages. [Note: A complete copy of SCDM is available at http://www.epa.gov/superfund/sites/npl/hrsres/tools/scdm.htm

. 3 U.S. Department of Interior Geological Survey (USGS). 1969. York North, Nebraska

Quadrangle, Missouri, 7.5

- Minute Series (topographic) (1969, photorevised in 1980) and York South, Nebraska Quadrangle, Missouri, 7.5

- Minute Series (topographic) (1969). 2 page s

. 4 Nebraska Department of Environmental Quality (NDEQ)

. Final Expanded Site

Inspection Report, Revision 01. January 19 , 2011

. 325 pages. 5 Nebraska Department of Environmental Control (NDEC)

. NDEC Site Investigation

Report : York Ground Water Contamination Site, York, Nebraska

. September 10 , 1991

. 2 82 pages. 6 EPA

. Expanded Site Inspection for the York Public Water Supply Site (Volumes I and

II)

. October 1996

. 65 2 pages.
7 NDEQ. Final Site Inspection, Revision 01, York Northeast Groundwater Site, York,

Nebraska. May 17 , 2010

. 40 3 pages.
8 Nebraska Department of Health & Human Services (NDHHS) . Ground water sample

result for PWS Well # 77

- 3 , from January 18, 1990. On

- line address: http://sdwis

dhhs.ne.gov

. Accessed on March 14 , 2013

. 3 pages. 9 N DHHS . Ground water sample result for PWS Well # 77

- 3, from October 27, 1993

.

On

- line address: http://sdwis

- dhhs.ne.gov . Accessed on March 14 , 2013 . 3 pages.
10 N DHHS . Ground water sample result for York Mobile Home Plaza , from May 15 , 199 1

.

On

- line address: http://sdwis

- dhhs.ne.gov . Accessed on March 14 , 2013 . 3 pages.
11 NDHHS. Ground water sample result for York Mobile Home Plaza, from December 20,

1994 . On

- line address: http://sdwis

- dhhs.ne.gov . Accessed on March 14 , 201 3 . 3 pages.
12 EPA. EPA Method 502.2, Revision 2.0

. 1989. 34 pages. 13 EPA. Removal Site Evaluation/Site Inspection Report for Southeast York Groundwater

Site, York, York County, Nebraska. February 16 , 2012

. 397 pages.10 References

14 USGS. Hydrogeologic Sett ing and Ground

- Water Flow Simulations of the Eastern High

Plains Regional Study Area, Nebraska. 2007. 32 pages.
15 USGS. Hydrogeology, Chemical Characteristics, and Transport Processes in the Zone of

Contribution of a Public

- Supply Well in York, Nebrask a. Scientific Investigations R eport 2008

- 5050. 2008. 165 pages.
16 EPA. Envirofacts Multisystem Database Query Results of Facilities in Near the Kroy

Building Products facility. On

- line Address: http://www.epa.gov/enviro/facts/multisystem.html . Accessed on September 11 , 2013

. 1 4 pages. 17 U.S. Census Bureau. 2010. Quickfacts Website. Accessed on March 27, 2013 . On

- line

address: http ://quickfacts.census.gov/qfd/ . 2 pages.
18 U.S. Department of Agriculture (USDA). Soil Survey of York County, Nebraska.

August 1977 . 60 pages.
19 Nebraska Department of Natural Resources (NDNR). 2010. Catalogue of registered

wells within 4

- mile Ta rget Distance Limit. On

- line Address: http://dnrdata.dnr.ne.gov/wellscs/Menu.aspx . Accessed on March 28, 2013. 2 pages.
20 Tetra Tech. Figure 3: Site Layout and Historical Results. Revised o n July 29 , 2013 . 1

page.
21 Tetra Tech. Figure 4 : Site Inspection Sample Results. Revised o n July 29 , 2013 . 1

page.
2 2 Tetra Tech. Figure 5 : 4

- Mile Target Distance Limit. Revised o n July 29 , 2013 . 1 page.
23 EPA Region 7. HRS Analysis Resul ts Supplement for ASR # 4844 for the York

Northeast Contamination Site

. May 1 , 2013

. 14 Pages

. 24 EPA. EPA Method 8260B , Revision 2.0 . December 1996

. 86 pages. 25 EPA. Manual for the Certification of Laboratories Analyzing Drinking Water

. January

20 05

. 2 09 pages. 26 EPA. U.S. EPA’s Methods and Minimum Detection Limits. On

- line Address:

http://www.epa.gov/ogwdw000/ccr/pdfs/list_ccr_mdl_and_methods.pdf . Accessed J uly 28, 2013. 6 pages.
27 GeoTrans , Inc . DNAPL Site Evaluation (excerpts). EPA/600/R

- 93/022. February 1993

.

49 pages.
28 Tetra Tech. Record of Communication between with Brandon Ostentows k i, Water

Engineer, with the City of York, Nebraska. July 29 , 2013 . 1 page

. 29 NDNR. Ground Water: Chapter 46, Article 6 (statutes). October 2004 . 38 pages.
30 University of Nebraska at Lincoln (UNL). Nebraska Statewide Test

- hole Database. On

line Address: http://snr.unl.edu/data/geologysoils/NebraskaTestHole/NebraskaTestHoleIntro.asp

. Accessed July 29 , 2013 . 10 pages.11 Site Summary SITE SUMMARY

The PCE/TCE Northeast Contamination site is identified near the intersection of N. Division Avenue and 26th Street (see Figure 1), near the northern edge of the City of York, Nebraska. The geographic
coordinates f

or the intersection are 40o 53’ 19.09 ” north and 97 o 36 ’ 01. 30 ” west. T he site includes an
area of contaminated soil in the industrial area to the northwest of the intersection and contaminated ground water extending southeastward into a residential area. The site encompasses portions of Sections 25 and 36 of Township 11 North, Range 3 West; Sections 29, 30, 31, and 32 of Township 11 North, Range 2 West; Sections 5 and 6, Township 10 North, Range 2 West; and Section 1 of Township 10 North, Range 3 West as depicted on the 7.5-minute topographic quadrangle maps for York North (Ref. 3). Prior to about 2005, when a bypass west of York was completed, N. Lincoln Avenue had been designated as U.S. Highway 81, and W. 25th Street as Nebraska Highway 34. The topographic map used for Figure 1 predates construction of the bypass and shows these roads as highways (Ref. 3, pp. 1-2; Figure 1).

The site is composed of documented releases of hazardous substances [volatile organic compounds (VOCs)] into wells associated with the local public drinking water supply and private residences, and a source area of VOCs at the former Kroy/Alcan facility (now separately-owned Kroy Industries and Kroy Building Products). According to the 2011 Nebraska Department of Environmental Quality (NDEQ) Expanded Site Inspection (ESI) findings, in 1995, Alcan conducted baseline and exit investigation of Kroy/Alcan. These investigations were conducted pursuant to the lease agreement covering the following specified substances: tetrachloroethene (PCE); 1,1,1-trichloroethane (1,1,1-TCA); 1,1-dichloroethylene (1,1- DCE ); 1,1,2- trichloroethane (1,1,2-TCA); trichloroethene (TCE); and trichlorofluoromethane (TCFM) (Freon 11). These investigations identified TCE; PCE; 1,1,1-TCA; and 1,1-DCE as present in the ground water at the former Kroy/Alcan facility. PCE was also identified in surface soil samples (Ref. 4, pp. 14-15). Based on results of the 2011 NDEQ ESI sampling, the source area for the contamination was suspected to be the area under or around production areas at Kroy Industries where solvents were used. TCE, PCE, and other solvents likely traveled through cracks, seams, drains, or other pathways through the concrete building slab and migrated to the ground water below. TCE and PCE were identified in soil gas, soil, and ground water near the production lines located in Building 1 (Ref. 4, pp. 38-39). PCE was identified in ground water by a burn pit near the northwestern corner of Building 1, where steel pipe production and a foundry had been formerly located. PCE was also identified in soils west of Building 2 during the ESI, and southeast of this building during the 2010 Site Inspection ( SI ) (Ref. 4, p. 59; 7, p. 46). TCE (maximum 30.9 micrograms per liter [μg/L]) was detected in ground water between about 91 and 110 feet below ground surface at temporary well ( TW

- K4 ), located about 0.5 mile12 Site Summary

downgradient of Kroy industries. Concentrations of PCE, 1,1-DCE, 1,1,1-TCA, carbon tetrachloride ( CCl 4 ), chloroform, and toluene were also detected at this location (Ref. 4, pp. 38-39, 47; 6, p. 12).

In 2011, TCE was found in four private drinking water wells at concentrations that exceeded the Cancer Risk (CR) screening concentration of 1  g/L (Ref. 2, p. 5). These wells served a total of eleven people. In addition, a public water well (well 81-1) was taken out of service in the past due to contamination; TCE was detected at a concentration of 35.7 (μg/L) in the well prior to it being taken out of service due to contamination. The population within 4-mile target distance limit (TDL) of 8,925 individuals is 844 more than the population served by the blended city water supply system (8,081) (Refs. 4, pp. 39-40; 28, p. 1 ). In summary, PCE, TCE, and 1,1,1-TCA ar e documented as present at and associated with Source 1 for the HRS scoring purposes; no other sources were evaluated for scoring. Source 1 constitutes contaminated soil source area for TCE, PCE, and other VOCs at Kroy Industries under or around Building 1 (Ref. 4, pp. 31-32, 38-39, 60). One municipal and five private wells contained TCE contamination above health-based benchmarks, resulting in approximately 612 individuals subject to Level I contamination (Refs. 5, pp. 13; 6, pp. 547-548, 645; 7, pp. 151, 229-231, 235-237, 241-249, 399- 401; 17, pp. 1-2).Source Number: 1

13 Source Characterizati on 2.2 SOURCE CHARACTERIZATION

2.2.1 SOURCE IDENTIFICATION

Name of source: Source 1 – Kroy Facility Contamin ated Soils
Number of source: - 1 Source Type : - Contaminated Soil Description and Location of Source (with reference to a map of the site): Figure 1

Source 1 is located near Kroy Building Products (KBP), which manufactures polyvinyl chloride (PVC) fencing, or Kroy Industries, Inc. (Kroy), which manufactures aluminum tubing and fittings. In the early 1990s, these now

- separate facilities were a single facility identified as Kroy Industries, a subsidiary of Alcan Pipe, a division of Alcan Aluminum Corporation (Kroy/Alcan) producing both aluminum and PVC pipe. Alcan purchased the facility in 1988. It previously had been Kroy Metal Products Inc., which had been in operation since 1956. These facilities are located at the northwest corner of W. 25th Street and N. Division Avenue in northwestern York, Nebraska (Figures 1 and 2). Review of the formal KBP letter of

response to EPA indicates that solvents, including TCE, were used as metal cleaners at the facility for

many years (Ref. 4, pp. 38-39; 6, pp. 53, 57, 62-64, 175-189).

In April and May 1991, the Nebraska Department of Environmental Control (NDEC) (NDEC is currently
known as NDEQ ) conducted a soil gas screening survey and found levels of various volatiles, including PCE, TCE, and 1,1,2- TCA (Ref. 5, pp. 26, 29). Similarly, field screening during the 1996 ESI conducted by EPA detected 1,1- DCE, CCl 4 , TCE, and PCE (Ref. 6, pp. 56, 62-64). These sample locations on the KBP facility are depicted on Figure 3 -4 of the report (Ref. 6, p. 53).

Soil samples collected in support of the 2011 NDEQ ESI at Kroy Industries contained TCE, PCE, , and low concentrations of, 1,1,1- TCA and 1,2,4- trimethylbenzene ( TMB ). It suggested the main source area for TCE, PCE, and other VOCs at Kroy Industries is under or around Building 1. Kroy Building 2 may be a source area for PCE contamination and other VOCs (Ref. 4, pp. 31-32, 38-39 , 60 ).

Kroy Building 1 is comprised of metal and wood structures that appear to have expanded from the central
barrel -roofed building where the 12 -inch pipe production lines are located (Ref. 4, p. 38) . TCE was identified in soil (SB -K1, from 0-2, 8-10, and 13-15 ft bgs) and soil gas (SG-23, from 6 and 8 ft bgs) collected from under this portion of the building (Ref. 4, pp. 26-27, 31) . The northwest corner of Building 1 housed the steel pipe shop and foundry at one time. PCE contamination was identified in ground water at TW -K3, just west of this portion of the building. Solvents used in the building may haveSource Number: 1

14 Source Characterizati on migrated to the underlying soi ls through cracks, seams, drains, or holes through the concrete building slab (Ref. 4, pp. 31-32, 38-39, 60) . A surface soil sample collected in 1995 at the pipe storage area west of Kroy Building 2 contained PCE at 49 μg/kg. Soil samples collected from 2-3 feet bgs and 8-10 feet bgs from the same general area during this investigation contained concentrations of PCE. This suggested potential PCE use at Kroy Building 2 (Ref. 4, p. 38).

HAZARDOUS SUBSTANCES ASSOCIATED WITH THE SOURCE

All Source 1 sample s were collected at the KBP facility property (see Figure 1). PCE and TCE were documented in Source 1 soil samples ( See Table 1 below ). The results presented from past source soil sampling activities suggest a confirmation of among other VOCs, PCE and T CE contamination at the site (Ref. 6, pp. 56, 62-64 ).

Background Samples
No background sample was collected for the 2011 ESI, which was primarily designed to sample suspected source areas at the facility. However, no VOCs (excluding acetone) had been de tected in the designated background soil sample collected west of the Kroy facilities during the Jan uary 2010 SI (Refs. 4, p. 50; 7, pp. 22, 29 ).

Co ntaminated Samples

The source hazardous substances are those hazardous substances documented in source soi l samples

. As
discussed in Section 2.2.1 and listed in Table 1 , PCE, TCE, and 1 ,1,1- TCA were detected in multiple source samples collected at Source 1. Six soil samples and a duplicate were submitted for ana lysis by Accutest and by the Plains Environment al Services (PES) mobile laboratory. Soil boring SB -K1 associated with Source 1 penetrated the soils beneath the concrete floor of Kroy Building 1 in the area where Kroy reported that solvents would have been used. This boring was placed between the pipe production line and the west wall of the building, and generally east of a small storage room having a “flammable” warning sign (Ref. 4, pp. 33 , 95 ). Table 1 depict s fixed laboratory and mobile laboratory
results of Source 1 from the same depths; based on the results, the mobile data and fixed laboratory data presented in the table demonstrate strong correlation. Numerous soil- gas samples from various depths collected in support of the 1991 NDEC SI found various VOCs at the Kroy facility at and around Sou rce 1, including PCE, TCE, and 1,1,1-TCA at up to 1,980 parts per billion (ppb), 1,820 ppb, and greater than 5,800 ppb, respectively (Ref. 5, pp. 26-29). Figure 1-2 in Reference 5 (Ref. 5, p. 26) d epicts the soil

- gas locations.Source Number: 1

15 Source Characterizati on Table 1: Fixed Laborato ry Analytical Results of Source 1 Samples Laboratory Sample Number (Location) Sample Depth (feet bgs) Sample Date Hazardous Substance Method Detection

Limit (u g/kg) Hazardous Substance Concentration ( u g/kg) * Reference Fixed Laboratory Results T61005

- 7 ( SB

- K1) 0

- 2 09/30/2010 PCE 0.96 28.7 4, pp. 32, 192, 215

- 217 TCE 2.1 16.9

T61005

- 8 (SB

- K1) 8

- 10 09/30/10 PCE 0.87 14.2 4, pp. 32, 192, 218

- 220 TCE 1.9 16.6

T61005

- 9 (SB

- K1) 13

- 15 09/30/10 PCE 0.86 25.2 4, pp. 32, 192, 221

- 223 33, TCE 1.9 26.1 1,1,1

- TCA 0.77 0.97 J Mobile Laboratory Results T61005

- 7 (SB -K1) 0

- 2 09/30/2010 PCE NA 65 4, pp. 32, 116 TCE NA 35

T61005

- 8 (SB -K1) 8

- 10 09/30/10 PCE NA 24 4, pp. 32, 116 TCE N A 21 T61005

- 9 (SB -K1) 13

- 15 09/30/10 PCE NA 85 4, pp. 32, 116 TCE NA 105

Notes:

* The samples submitted to the fixed laboratory were analyzed using EPA Method SW846 8260B ; associated Method Detection Limit s (MDL) are included in their respective raw data results pages (Ref. 4, p. 188)

. J The analyte was positively identified; the associated numerical value is the approximate concentration of the analyte in the sample (Ref. 4, p. 187)

. NA Not Available

2.2.2 HAZARDOUS SUBSTANCES AVAILABLE TO A PATHWAY

Table 2: Containment Factors for Source No. 1
Containment Contai nment Description Factor Value Ref erences Gas release to air Not Scored NA Particulate release to air Not Scored NA Source 1 has no liner. Therefore, the highest ground water migration pathway containment factor value of 10 was assigned to Source Number 1 as specified in Table 3

- 2 of the HRS (Ref. 1, Section 3.1.2.1). 10 4, pp. 46

- 47 38

- 39
,

Release via overland migration and/or flood

. Not scored NASource Number: 1

16 Source Characterization 2.4.2 HAZARDOUS WASTE QUANTITY

2.4.2.1.1 Hazardous Constituent Quantity - Tier A
The hazardous constituent quantity for Source No. 1 could not be adequately determined according to the HRS requirements; that is, the total mass of all Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) hazardous substances in the source is not known and cannot be estimated with reasonable confidence [Ref. 1, pp. 51590-51591 (Section 2.4.2.1.1)]. There are insufficient historical and current data (Manifests, PRP records, State records, Permits, Waste concentration data, etc.) 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 evaluate the associated releases from the source to calculate the hazardous constituent quantity for Source No. 1 with reasonable
confidence.

Hazardous Constituent Quantity Assigned Value: NS

2.4.2.1.2 Hazardous Wastestream Quantity

– Tier B
The hazardous wastestream quantity for Source No. 1 could not be adequately determined according to the HRS requirements; that is, the total mass of all hazardous wastestreams and CERCLA pollutants and contaminants in the source is not known and cannot be estimated with reasonable confidence [Ref. 1, pp. 51591 (Section 2.4.2.1.2)]. There are insufficient historical and current data (Manifests, PRP records, State records, permits, etc.) available to adequately calculate the total mass of all hazardous wastestreams and CERCLA pollutants and contaminants in the source and the associated releases from the source. Therefore, there is insufficient information to evaluate the associated releases from the source to calculate the hazardous wastestream quantity for Source No. 1 with reasonable confidence.

Hazardous Wastestream Quantity Assigned Value: NS

2.4.2.1.3 Volume

–

Tier C

Ho rizontal and vertical extent of the source cannot be determined based on available sampling data; a sufficient number of samples is not available to statistically represent the range of contaminant concentrations throughout the source (Ref. 1, Section 2.4.2.1.3).

Volume Assigned Value: 0Source Number: 1

17 Source Characterization 2.4.2.1.4 Area

–

Tier D
Soil samples were collected from Source 1, as presented in Table 1 of this documentation record and
shown in Figures 3 of the NDEQ ESI report (Ref. 4, p. 59). These samples we re collected from one soil boring location. In addition to samples included in Table 1, historical data has shown the presence of Source 1-related contaminants in the area; however, the areal extent of the contamination cannot be accurately determined based on available sampling data (Ref. 5, pp. 26-29). It is not known whether contamination in Source 1 is continuous throughout and the extent of contamination is not defined. The area of Source 1 is undetermined, but greater than zero square feet (Ref. 1, Section 2.4.2.1.4).

Sum (ft 2 ): >0 Equation for Assigning Value (Ref. 1, Table 2-5): Area (A)/34,000

Area Assigned Value: >0Source Number: 1

18 Source Characterization 2.4.2.1.5 Source Hazardous Waste Quantity Value
Highest assigned value assigned from Table 2-5 (Ref. 1, p. 51591):

SUMMARY OF SOURCE DESCRIPTIONS

Table 3: Summary of Sources Descriptions
Containment Factor Value by Pathway

Surface Water (SW) Air Source Hazardous Ground GW to Source Constituent Water SW Gas Particulate Hazardous Quantity (GW) Overland/flood ( Ref. 1, ( Ref. 1, ( Ref. 1, Source Waste Quantity Complete? ( Ref. 1, ( Ref. 1, Table Table Table Table No. Value (Y/N) Table 3

- 2) 4

- 2) 3

- 2) 6

- 3) 6

- 9) 1 >0 No 10 Not Scored Not Not N ot Scored Scored Scored19 GW - General

3.0 GROUND WATER MIGRATION PATHWAY

3.0.1 GENER

AL CONSIDERATIONS
Regional Setting
Topography in the northern York area is relatively flat, with a slight slope to the east. The elevation at the site is about 1,650 feet above mean sea level (MSL) (Ref. 3, pp. 1-2). York is in the upland area between Lincoln Creek, about 1.5 miles to the north, and Beaver Creek, about 1.75 miles to the south. Lincoln Creek, which has an elevation of about 1,600 feet above MSL, flows generally southeastward west of York, but makes an abrupt turn to the northeast north of the intersection of N. Lincoln Avenue
and 25 th Street. Beaver Creek is at an elevation of about 1,580 feet amsl and flows generally eastward at the southern edge of York. Lincoln Creek flows into the Big Blue River near Seward, Nebraska, about 25miles east of York. Beaver Creek flows into the West Fork of the Big Blue River about 14 miles eastsoutheast of York. Drainage in the site area is generally to the south or southeast through ditches and intermittent streams (Ref. 3, pp. 1-2; 4, pp. 6-7).

Climate and Regional Geology
The climate in York County is continental, with cold winters and hot summers. The average annual precipitation is about 27.5 inches; however, this varies widely. As of 1999, the driest year on record involved 14.93 inches of precipitation during 1894, while the wettest year on record involved 39.33 inches of precipitation in 1908. Temperatures have ranged from 114 degrees Fahrenheit (oF) to -31oF (Ref. 18, pp. 52-53).

Soils in the northeastern York area primarily belong to the Hastings-Fillmore association of deep, nearly level to gently sloping silty soils that formed on loess in upland areas (Ref. 18, pp. 6-7, 60). Ground water flow in the High Plains aquifer around the York area has been the subject of several USGS investigations since the discovery of the ground water contamination at the York PWS site. Quaternary alluvial deposits of the High Plains aquifer system provide ground water in the area. The High Plains aquifer system covers thousands of square miles in eight states (Ref. 14, p. 6). This aquifer consists of fluvial sands, gravels, silts, and clays in confined and unconfined layers. In the York area, the uppermost layer consists of unsaturated loess having a maximum thickness of about 88 feet (Ref. 14, p. 9). Below that is a maximum of about 140 feet of sand and gravel with some lenses of silt and clay. The unconfined water table occurs near the top of these sands and gravels. Typically, silts and clays and finer sands and gravels increase with depth in this aquifer layer. The third layer consists predominantly of clayey glacial till with silts above and below the till. This layer has maximum thickness of about 115 feet; however, it is absent in a few locations southeast of York. This till layer serves as a confining layer for the unit below.20 GW - General

In the York area, a maximum of about 80 feet of fine- to medium-grained sand with minor amounts of gravel underlies the till; however, this unit is thin or absent northwest of York. A lower confining layer consisting of about 105 feet of silts and clays with some interbedded sands underlies the sand aquifer. This heterogeneous unit thins to both the northwest and southeast, and units are believed to be largely discontinuous. Interbedded fine to medium sands and silty clays form a lower confined aquifer unit under this lower confining layer. The lower confined aquifer layer has a maximum thickness of about 160 feet and thins to the northwest and southeast of York (Ref. 14, pp. 5, 9-12).

These Quaternary deposits are underlain by the Late Cretaceous Carlile Shale in the York and southeastern York area. Chalky shales and chalks of the Cretaceous Niobrara Formation underlie the Quaternary deposits northwest of York, overlying the Carlile Shale. This less permeable bedrock forms the base of the High Plains aquifer (Ref. 14, p. 10)

.
Previous investigations in the northeastern York area indicate that about 58 feet of loess overlies about 94 feet of sand, gravelly sand, and gravels interbedded with silt and clay (the unconfined aquifer). Thes e overlie the clay and glacial till aquitard, which is about 31 feet thick. The lower aquifer consists of about 231 feet of sand interbedded with silt and clays overlying the Cretaceous-aged bedrock (Ref. 6, pp. 71- 72). The USGS divided the lower aquifer into the upper and lower confined aquifers separated by the clayey glacial till aquitard (Ref. 14, p. 12 ).

Most private wells in the area likely are producing from the upper unconfined aquifer. Public water supply wells for which screening information is available appear to be screened over multiple intervals between about 127 and 394 feet below ground surface (bgs) (Ref. 6, pp. 49, 561-562). USGS studies indicate older public wells and irrigation wells were commonly screened in the unconfined aquifer an d both the upper and lower confined aquifers (Ref. 14, p. 13). USGS concluded that ground water withdrawals from the confined aquifers induce large downward vertical gradients, and these wells form a conduit for contamination in the unconfined aquifer to travel downward into the upper and lower confined aquifers (Ref. 14, pp. 9, 13). While the aquifer consists of many layers, evidence of contaminant migration, as discussed above and shown via ground water sample results, demonstrates that any confining layers present are not functioning competent or impermeable barriers to ground water/contaminant flow in the site vicinity; thus the aquifer beneath the site is, for HRS scoring purposes, considered equivalent to a single interconnected aquifer system (Ref. 1, Section 3.0.1.2.1).21 GW - General

Ground water flow in the York area is predominantly from northwest to southeast (Ref. 14, p. 12). Saturated thickness increases with the thickness of the Quaternary deposits and is about 350 feet in the York area. The High Plains aquifer is in hydraulic connection to the major east-flowing rivers in the area, and during periods of low flow, these major rivers derive most of their flow from ground water discharge. Ground water flow likely discharges to the West Fork of the Big Blue River. No naturally perennial streams are present in the York area other than the lower reaches of Beaver Creek east of York, where flow derives from discharges from the York wastewater treatment plant and York Cold Storage. Figure 5-2 in the 1996 EPA ESI includes the local geologic/hydrogeologic column (Ref. 6, p. 81).

Site Geology

The soil types represented in the immediate vicinity of the Kory facility are the Hastings-Fillmore Association. It is characterized by deep, nearly level to gently sloping silty soils that have a claypan subsoil (Ref. 18, p. 60). Boring logs from the Kroy facility sampling locations SB -K1 and SB-K2 are included in Reference 4, pages 102 and 103. Geologic cross-section of the site, including the location of well 81-1 is presented in Reference 6, pages 536 and 538. Figure 5-2 in Reference 6 depicts the local geologic/hydrogeologic column (Ref. 6, p. 81).

Boring logs for three Nebraska test holes in the area near the Kroy facilities generally describe a silt layer above alluvial sands, silts, and gravels; then a glacial till, and additional sands and silts above Cretaceous Carlile shale bedrock. At test hole 58-A-57, about 0.5 mile southeast of Kroy, silt was present to 58 feet bgs; sands, gravels, and silts were below that to 159.5 feet bgs where glacial till was present to174 feetbgs; and then sands and silts were logged to bedrock at 415 feet bgs (Ref. 30, pp. 4-6). At test hole 46-B46, located about 1 mile north of Kroy, silts and clays were present to 38.5 feet bgs, and were underlain by sands, silts, and gravels to 144 feet bgs, where the glacial till was encountered. The till extended from 144 to 182 feet bgs, with sands and silts below that to Cretaceous Carlile shale bedrock at 387 feet bgs (Ref. 30 pp. 7-8). A test hole about 3 miles north of Kroy (56-B-49) silt was encountered to 38 feet bgs ; sands, silts, and gravels were logged to 141 feet bgs; glacial till was present from 141 to 199.5 feet bgs; and silts and sands were present below the till to Cretaceous Carlile shale bedrock at 351 feet bgs (Ref. 30 pp. 9-10).3.1 LIKELIHOOD OF RELEASE

3.1.1 OBSERVED RELEASE
Aquifer Being Evaluated: Quaternary alluvial deposits of the High Plains aquifer

Chemical Analysis

Background Concentrations : A background level for a site provides a reference point by which to
evaluate whether or not a release of a hazardous substance or substances have occurred associated with a

source and attributable to the site. Determining background level is necessary to establish an observed release (or observed contamination) by chemical analysis. When chemical analysis is used to determine background levels, the background and release samples must be from the same medium, in this case ground water, and should be similar as possible except for poten tial influence from the site. To establish
an observed release for this site
, contamination in multiple well s and private wells over time extending from 1990 through 2011 was considered (Ref. 4, pp. 20, 63-69 ). Review of current and historical data
indic ated the presence of elevated levels of VOCs in wells do wngradient from Source 1 ( Ref. 4, pp. 62- 69). In the latest known sampling effort in support of the 2010 NDEQ SI, no VOCs were identified in the background private well sample (PW-6) (Ref. 7, pp. 26, 46); no VOCs were reported in the background municipal well 77-3 in its latest known sampling in 2008, conducted by the Nebraska Health and Human Services (NHHS) ( Ref. 7, pp. 33, 45, 50). Similarly, no VOCs were reported in well 77 -3 its 1990 and
1993 sa mpling ( Ref s. 8; 9 ; 20, p. 1 ).

22 GW – Likelihood of Release23 GW – Likelihood of Release Table 4 : Select Background Ground Water Collected at Drinking Water Wells Samples

Sample ID Total Depth (below ground

surface) and aquifer Screened a Date Sampled Location Description References
Public Water S upply
150

- 90060 15392183 and 292 feet 15 0

- 292 feet 01/18/90; 10/27/93 PWS Well # 77

- 3; located 1.3 miles southwest of KBP Ref. 3 ; 9, 4, pp. 42, pp 1

- 3 64; 7, p. 50; 8, pp 1

-

DE1GB

- 00 2 292 feet 15 0

- 292 feet 11/13/95; PWS Well # 77

- 3; located 1.3 mil es southwest of KBP Ref. 6, pp. 333, 342 , 484, 490

- 491

3344V and 9001V 100 feet a Unknown 05/15/ 91 and 12/20/ 94 York Mobile Home Plaza, located approximately 1.75 miles southwest of KBP Ref. 371 10, pp. 1

- 3; 11, pp. 1

- 3; 13 p.

Non

- Public Water Supply
T4 6518

- 25 a Unknown a Unknown 01/27/10 PW

- 6, located approximately west of KPB 0.9 mile Ref. 4, pp. 223

- 225 18, 20, 59; 7, pp. 89,

a Of 48 registered domestic wells within 4 mile radius of site, 37 have total depths between 72 and 135 feet bgs (Ref. 4, pp. 105-112).24 GW – Likelihood of Release Table 5 : Select Background Ground Water Samples Results Collected by the State of Nebraska Reporting Limit or Method Detection Limit Sample ID Hazardous Substance Results (μg/L) References
150

- 90060 PCE ND 0.5 Ref. 8, pp

. 1

- 3 TCE ND 0.5
153 92183 PCE ND 0. 2 Ref. 9, pp

. 1

- 3 TCE ND 0. 2
3344V PCE TCE ND ND 0. 2 0. 2 Ref. 10, pp

. 1

- 3

9001V PCE TCE ND ND 0. 2 0. 2 Ref. 11, pp

. 1

- 3

1 T46518

- 25 PCE ND 0.5 Ref. 4, pp. 18, 20, 59; 7, pp. TCE ND 0.5 89, 150, 223

- 225

1 150

- 91423 PCE ND 0.5 Ref. 5, pp. 11, 12, 23, 191 TCE ND 0.5

1 DE1GB

- 002 PCE TCE ND ND 0.5 0.5 Ref. 491 6, pp. 333, 342, 484 , 490

-

Notes: 1 Because these samples were analyzed by EPA Region 7 laboratory for drinking water or by the state regulatory programs that adhere to EPA methods, the re spective required method detection limit has been used for comparative purposes (Ref. 1, Section 1.1; Definitions; 6, p. 349; 25, p. 52; 12; 26, p. 4 ).

ND Non Detect μg/L micro grams per liter PCE Tetrachloroethene TCE Trichloroethene Contaminated Samples
Numerous sampling efforts have taken place in the general site area since 1990 (Ref. 4, pp. 10-21). Sampling effort in support of the state of Nebraska and EPA included a collection of private wells in the site vicinity and from the York public wells. Seven private well samples - including one background presented in Tables 4 and 5 and remaining downgradient release samples presented in Tables 6 and 7

– were collected in January and March, 2010; five of the downgradient wells contained TCE, includin g three residences with concentrations above its MCL (Ref. 7, p. 25). All analytical results associated with the historical samplings are presented in Appendix B of the SI (Ref. 4, pp. 62-69). TCE was consistently found in public supply well 81-1. Consequently, this well was isolated from the public supply due to VOC contamination (Ref. 6, pp. 78, 600; 7, p. 31). Further, as depicted in Figure 2, ground water samples collected from 93-97 feet bgs at a temporary well TW -K1, as well as the samples collected 10 feet above this interval reported TCE at 4.4 μg/L and 2 μg/L, respectively. Another temporary well, TW-25 GW – Likelihood of Release

K2, p laced immediately west of Building 1 contained TCE concentration of 1.2 μg/L (77 to 81 feet bgs) (Ref. 4, pp. 34, 200-205, 209-211).

Table 6: Contaminated Ground Water Samples

Collected by the State of Nebraska and EPA a

Sample ID Total Depth ( below ground

surface) and

aquifer a,b Screened (feet) Date Sampled Location Description References Public Water Supply
DE1GB

- 008 and 81

- 1 38 5 feet

– unconfined confined and 145

– feet 385 11/13/95; 3/14/90 PWS 81

- 1 Ref. 333, 4, p. 349, 65; 5, p. 22; 6, pp. 484, 492

- 93; 7, p. 32

Non

- Public Water Supply (Private Wells ) a
T46518

- 31 (Estimated) feet 120 Unknown 01/26/10 PW

- 1 Ref. 7, pp. 18, 25, 8 1

T46518

- 32 119 feet Unknown 01/26/10 PW

- 2 Ref. 7, pp. 18, 25, 83
T46518

- 27 126 feet Unknown 01/26/10 PW

- 3 Ref. 7, pp. 18, 25, 85
T46518

- 29 Unknown Unknown 01/26/10 PW

- 4 Ref. 7, pp. 25, 86
4844

- 5 Unknown Unknown 03/16/10 PW

- 5 Ref. 7, pp. 25, 118,
4844

- 7 Unknown Unknown 03/16/10 PW

- 8 Ref. 7, pp. 25, 118 Notes: a Private well samples collected in January 2010 were analyzed by Accutest Laboratory with internal job number T46518; the analyzing laboratory confirmed that all samples were received properly preserved and were processed within the established holding time. No anomalies were found with the chain of custody and no data were qualified (Ref. 7, pp. 142-144, 147, 263). Private well samples collected in March 2010 were analyzed by the EPA
Re gion 7 analytical laboratory (Ref. 7, p. 118). These sampling locations are depicted on Figure 3 in Reference 7 (p. 46). b Of 48 registered domestic wells within 4 mile radius of site, 37 have total depths between 72 and 135 feet bgs (Ref. 4, pp. 105-112).26 GW – Likelihood of Release Table 7 : Contaminated Ground Water Samples Results Collected by the State of Nebraska and EPA

Hazardous Reporting Sample ID Substance Results (μg/L) Limit (μg/L) References
DE1GB

- 008 TCE 2.2 1 0.5 Ref. 4, p. 65; 6, pp. 333, 349, 484, 492

- 93
81

- 1 TCE 35.7 3 <1.3 Ref. 5, p. 22

2 T46518

- 31 TCE 7.2 2.0 Ref. 7, pp. 151, 241

- 243,

2 T46518

- 3 2 TCE 4.7 2.0 Ref. 7, pp. 151, 244

- 246

2 T46518

- 27 TCE 9.6 2.0 Ref. 7, pp. 151, 229

- 231

2 T46518

- 29 TCE 45.5 2.0 Ref. 7, pp. 151, 235

- 237

2 4844

- 5 TCE 53 0.50 Ref. 7, pp. 394 , 399

- 401 ; 23, PCE 1.9 pp. 1, 8

2 4844

- 7 TCE 3.3 0.50 Ref. 7, pp. 394, 399

- 401 ; 23, PCE 0.85 pp. 1, 11

Notes:
1 Because the sample was analyzed by EPA Region 7 laboratory for drinking water, the required method detection limit has been used (Ref. 1, Section 1.1, Definitions; 6, p. 349; 25, p. 52 ).
2 Analyzed using EPA Method SW846 8260B (Ref. 4, p. 33, ; 7, pp. 22, 26 ,, 152; 24)

3 Reporting limit anticipated less than 1.3 as lowest detection in dataset was 1.3 (Ref. 5, p. 22).27 GW – Likelihood of Release

Level I Sampl e Sample DE1GB-008 collected from York public drinking water well 81-1 and listed in Table 8 contained TCE at concentration above its cancer risk screening concentration (CR) of 1 μg/L (Ref. 2, pp. 4-5). Multiple sampl es collected from this well have documented levels of TCE (Ref. 4, p. 65; 6, p. 10 ); consequently, this well was isolated (closed) from the public supply due to contamination (Ref. 4, p. 40 ;28, p. 1). In addition, five additional residential drinking water wells contained TCE above its healthbased benchmarks. These samples met the observed release and Level I concentration criteria (Ref. 1, Table 2-3, Table 3-10, and Section 2.5).

Municipal and Residential Drinking Water Wells

Table 8 : Actual Contamination D ri nking Water Well s Laboratory Sample Sample No. Analyte Results Units Date Well ID 1 References Municipal DE1GB

- 008 TCE a 2.2 μ g/L 11/13/95 York public Ref. 4, p. 65; 6, pp. 333, well 81

- 1 349, 484, 492

- 93 81

- 1 TCE 35.7 μg/L 3/14/90 York public Ref. 5, p. 22 well 81

- 1 Residential/Private Wells T46518

- 31 TCE a 7.2 μg/L 01/26/10 PW

- 1 Ref. 7, pp. 151, 241

- 243, T46518

- 3 2 TCE a 4.7 μg/L 01/26/10 PW

- 2 Ref. 7, pp. 151, 244

- 246 T46518

- 27 TCE a 9.6 μg/L 01/26/10 PW

- 3 Ref. 7, pp. 151, 229

- 231 T46518

- 29 TCE a 45.5 μg/L 01/2 7 /10 PW

- 4 Ref. 7, pp. 151, 235

- 237 4844

- 5 TCE a 53 μg/L 03/16/10 PW

- 4 Ref. 7, 23, pp. pp. 394, 1, 8 399

- 401 ;

4844

- 7 TCE a 3.3 μg/L 03/16/10 PW

- 8 Ref. 7, pp. 394, 399

- 401 ; 23, pp. 1, 1 1 Notes: a The MCL, CR, and RfD concentrations for TCE are 5 μg/L, 1 μg/L, and 7.8 μg/L, respectively (Ref. 2, p. 5). 1 Well locations are depicted in Figures 2 and 3 of Reference 4, pp. 58- 59 and Figure 4 of this HRS
documentation record.

Attribution
PCE and TCE were documented in the contaminated soils (Source 1) at the KPB facility (see analytical data evidence depicted in Table 1 of this documentation record) (Ref. 4, pp. 32, 192, 215-223 ). Only these two compounds are being considered for scoring purposes. However, historically, various28 GW – Likelihood of Release

additional VOCs

–

including but not limited to 1,1,2-trichloroethane (1,1, 2-TCA); 1,1,1-trichloroethane ( 1,1,1-TCA); 1,1 -DCE, and TCFM have been found in soils at the KPB facility (Ref. 6, pp. 12, 62-64).

Review of analytical data indicates elevated levels of TCE in samples collected downgradient (ground water flows east/southeast [Ref. 5, p. 20; 6, pp. 73, 635] ) of the KPB facility, as evidenced by elevated levels of TCE in immediately downgradient drinking water wells such as PW-1, PW-2, PW-3, PW-4,
PW -8, and public water well 81-1 (Ref. 4, pp. 58-59). In addition, temporary wells (TW-3, TW-4, and
TW -6) depict a similar trend of elevated levels of TCE extending east/southeast from the KPB facility, with no VOCs associated with Source 1 in the background well (TW-9) (Ref. 4, p. 59). Ground water samples presented in Tables 7 and 8 above contain elevated concentrations of PCE, which was found in Source 1 described in Section 2.2; as described in Section 2.2, Source 1 also contained TCE.

A list of possible offsite sources was initially reported in the 1991 NDEC Site Investigation (SI) report, which included a soil-gas screening study (Ref. 5, pp. 14, 29, Appendix B). The 1996 ESI report completed by EPA included updated information on these potential sources, based on questionnaires completed by facility representatives (Ref. 6, pp. 10-15, Appendix B). The following information is summarized from these two reports. Batterton Waterproofing

Located at 308 Marquis Avenue, the company provided waterproofing services on grain elevators; there were two above-ground storage tanks located on the property, one for diesel fuel and one for gasoline. The company representative indicated in the 1990s that no spill has occurred on the facility. The soil gas survey conducted by NDEC showed TCE on the property (Refs. 5, pp. 29, 60; 6, p. 11).

Cyclonaire

Located at 2922 Division Avenue, the facility was originally built by Metcut and operated as a machine shop from 1978 to about 1983. Dale Electronics, Inc., was located at the same location prior to 1987. It was a small quantity generator of hazardous F005/D001 waste, denoting the possible use of some or all of the following spent non-halogenated solvents: toluene, methyl ethyl ketone, carbon disulfide, isobutanol, pyridine, benzene, 2-ethoxyethanol, and 2 nitropropane. Cyclonaire uses water-based thinner; waste is picked up for disposal by Safety Kleen. The 1991 soil-gas survey performed by NDEC found trichlorofluoromethane (TCFM) (Refs. 5, pp. 60, Appendix B; 6, p. 11).

York Heating and Air Conditioning (Lloyds Body Shop)

Located at 3026 North Division Avenue, it owned the Lloyds Body Shop property. The 1991 soil-gas survey performed by NDEC indicated the presence near the property of PCE and TCE. York Heating and29 GW – Likelihood of Release

Air C onditioning used coil cleaners at a rate of less than one gallon per year; as a practice, the waste cleaner was poured on the concrete to evaporate . Lloyd’s Body Shop used paint and paint thinner, which were reported to be recycled (Refs. 5, pp. 29, 59; 6 p. 13).

Maken Equipment and Irrigation

Located at the junction of U.S. Highway 81 and 34, it was a farm implement dealer. The company representa tive stated that no spills had been recorded at the site. An underground storage tank for unleaded gasoline was removed in 1994. The soil-gas survey performed by NDEC in 1991 showed TCE on its property (Refs. 5, pp. 29, 60, Appendix B; 6, p 13).

Former Commodity Credit Corporation (Miller Seed and Supply)

Located on the west side of Division Avenue, approximately 0.5 miles north of the intersection of Division Avenue and Highway 34, Miller Seed and Supply, Plains Power, Miogen Seed Company, and Dallas Stauber leased the property. The1991 soil-gas survey performed by NDEC showed carbon tetrachloride and chloroform. No records of the amounts of chemicals used were available (Refs. 5, pp. 29, 61; 6, pp. 13 -14).

Midwest Valley Chemical (Former location of Omega Transport Corporation)

Located at 2700 North Division, Omega Transport Corporation previously operated on this property as a truck repair station. The NDEC soil-gas survey indicated 1,1,1-TCA, TCE and TCFM. Midwest Valley Chemical purchased the property in 1994 and used it to store herbicide, insecticide, and fungicide (Refs. 5, pp. 29, 59, 60; 6, p. 14).

Sundstrand Aviation

Located at 2800 Division Avenue, it manufactured equipment and parts for aircraft and operated a metal turning/grinding facility. The NDEC soil-gas survey found PCE, 1,1,1-TCA and 1,1-DCE at the property. Further information obtained by EPA in 1992 indicated that Sundstrand used 1,1,1-TCA, PCE, hydrochloric acid, nitric acid, sulfuric acid, sodium hydroxide, acetone, chromic acid, hexachlorobenzene, and others. Between 1987 and 1990, Sundstrand reportedly releas ed approximately 47,000 pounds of 1,1,1-TCA and 76,000 pounds of PCE (Refs. 5, pp. 29, 59, 60; 6, pp. 15, 232-238). The releases associated with the Sundstrand facility are documented by EPA as air releases (Ref. 16, pp. 3-4).It is significant to note that, in the NDEC soil-gas study referenced above, the facility exhibiting the

highest levels of PCE and its breakdown products in the greatest number of samples was the Kroy/Alcan facility (Ref. 5, pp. 26-29). All of these locations are depicted on page 25 of Reference 6.

A query of Enviromapper for Envirofacts near KPB found eight facilities, including the seven listed above, plus the Kroy/Alcan facility, with only Hamilton Sundstrand included in the Toxics Release Inventory (TRI) Program. All reported PCE releases from this facility were air releases (Ref. 16, pp. 2-4 ). Meanwhile, soil samples collected at the KPB facility continue to show elevated levels of VOCs associated with Source 1 (Ref. 4, pp. 32, 38-39). In addition, documentation of past interviews and responses from Kroy representatives have confirmed use of chlorinated solvents at the facility. Large quantities of solvents, including TCE, were purchased by the facility and used for cleaning metals; Building 1, associated with Source 1, contained vehicle maintenance and production areas. It included mills for the manufacture of rolled and welded aluminum pipe and polyester coated fittings. In addition, operations in the building included steel fabrication, fitting, and dry storage (Ref. 6, pp. 176-190). As discussed earlier, soil and ground water samples collected at and downgradient of the Kroy facility since the 1990s have shown elevated levels of TCE and PCE. Sampling continues to show the presence of chlorinated solvents in ground water samples collected downgradient of the facility. Because they are heavier than water, gravity forces cause the downward migration of chlorinated Dens e Non-Aqueous Phase Liquids (DNAPLs), such as TCE and PCE to migrate downward through the vadose zone as a distinct liquid. This migration is often accompanied by lateral spreading due to the effects of capillary forces and medium spatial variability (Ref. 27, pp. 10-11, 33. 43-44). These characteristics of DNAPLs may explain how soil contamination (PCE and TCE) detected at depths of up to 15 feet underneath Building 1 at the former Kroy/Alcan facility (see Section 2.2 of this documentation record) have come to be present in drinking water wells downgradient from the contaminated soil source (see Section 3.1.1 of this documentation record). Further, many irrigation and older public supply wells are screened across both the unconfined and upper and lower confined layers of the aquifer. Those wells with multiple screened intervals and boreholes penetrating confining layers provide pathways for water and contaminants to move to deeper parts of the aquifer (Refs. 4, pp. 105-112; 14, p. 13).

Hazardous Substances Released: PCE, TCE

Ground Water Observed Release Factor Value: 550

30 GW – Likelihood of Release31 Waste Characteristics

3.1.2 POTENTIAL TO RELEASE

Not Evaluated

3.2 WASTE CHARACTERISTICS

3.2.1 TOXICITY/MOBILITY

Table 9: Toxicity/Mobility
Does Haz. Substance Meet Toxicity/ Toxicity Mobility Observed Mobility Source Factor Factor Release? (Ref. 1, Table 3- Hazardous Substance No. Value Value (Y/N) 9) Reference PCE 1 100 1 Yes 100 1, section TCE 1 , 000 1 Yes 1 ,000 3.2.1.2; 2, pp. 2

- 3 2, pp. 4

- 5
Toxicity/Mobility Factor Value: 1,000

(Ref. 1, Table 3-9)

3.2.2 HAZARDOUS WASTE QUANTITY

Table 1 0 : Hazardous Waste Quantity Value
Source No. Source Type Source Hazardous Waste Quantity 1 Contaminated Soil > 0

The hazardous constituent quantity for Source 1 is not adequately determined. Its source HWQ is undetermined, but greater than zero. As specified in Reference 1, Section 2.4.2.2, a HWQ factor value of 100 was assigned because targets in the ground water migration pathway are subject to actual contamination at Level I concentrations (Ref. 1, Section 2.4.2.2 ).

Sum of Values: > 0 Hazardous Waste Quantity Factor Value: 100 (Ref. 1, Table 2- 6)32 Waste Characteristics

3.2.3 WASTE CHARACTERISTICS FACTOR CATEGORY VALUE
As specified in the HRS (Ref. 1, Section 3.2.3), the Hazardous Waste Quantity Factor Value of 100 was multiplied by the highest toxicity/mobility value of 1,000 for TCE, resulting in a product of 100,000 (1.0E+05). Based on this product, a waste characteristics factor value (WCFV) of 18 was assigned from Table 2-7 of the HRS (Ref.1, Section 2.4.3.1).

Toxicity/Mobility Factor Value: 1,000 Hazardous Waste Quantity Factor Value: 100

Toxicity/Mobility Factor Value X Hazardous Waste Quantity Factor Value: 100,000 Waste Characteristics Factor Category Value: 18 (Ref. 1, Table 2-7)33 Targets

3.3 TARGETS

3.3.1 NEAREST WELL

Well IDs: 81-1, PW-1, PW-2, PW-3, PW-4, PW-8 Level of Contamination (I, II, or potential): I As documented in Section 3.1.1 above (see Tables, 6, 7, and 8), there are numerous samples from drinking water wells containing TCE at concentrations that both meet the observed release criteria and exceed the cancer risk screening benchmark. Therefore, in accordance with Reference 1, Section 3.3.1, Table 3-11, a nearest well factor value of 50 is assigned to the site.

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

3.3.2.1 Level of Contamination
Presented below in Section 3.3.2.2 are the numbers of people drinking from wells that have documented
actual contamination based on hazardous substance concentrations that meet the observed release criteri a (see Section 3.1.1 of this document). Section 3.3.2.2 presents the number of people drinking from wells
that contain hazardous constituents above a health-based benchmark.34 Targets

3.3.2.2 Level I Concentrations (concentrations associated with Level I targets are presented in Section 3.1.1)
The concentrations of TCE in the samples DE1GB- 008 , T46518-31, T46518-32, T46518-27, T46518-29, 4844- 5, and 4844-7 below are above the HRS health based benchmark used for comparison and are documented in Section 3.1.1. Sample DE1GB-008 from York public drinking water well 81-1 and samples 4844-7 and T46518-32 collected from residential drinking water wells

– as listed in Table 8

– contained TCE at concentration above its cancer risk concentrations (CR) of 1 μg/L . For scoring purposes, the actual number of apportioned individuals subject to Level I contamination at the time of well closure associated with York public supply well 81-1 were used; the well was closed due to contamination. Highest concentration of TCE up to 51.8 μ g/L was found in well 81-1 during investigations conducted in 1990 and 1991 (Ref. 5, pp. 7, 21-22). At the time, the city of York had 13 wells total connected with the blended public water supply (Ref. 28, p. 1). No well had capacity exceeding 40 percent of the system capacity; therefore, the population w as allocated equally for each well after excluding the population associated with 30 private wells (Ref. 5, p. 13; 6, p. 645):

[7,884 total population]

– [30 residential wells X 2.37 persons/household*] = 7,812 individuals
Therefore, 7,812 individuals ÷ 13 = 601 persons
(*This is based on 7,884 people divided by 3,323 housing units in York, Nebraska [Ref. 6, p. 548])
In addition, other private wells subject to Level I contamination are included in Table 11.

Table 1 1 : Level I Targets Laboratory Sample No. Well ID Population Reference DE1GB

- 008 York Public Well #81

- 1 60 1 Ref. 5, pp. 13; 6, pp. 547

- 548 , 645 T46518

- 31 PW

- 1 2. 31 Ref. 7, pp. 151, 241

- 243 ; 17, pp. 1

- 2 T46518

- 3 2 PW

- 2 2. 31 Ref. 7, pp. 151 , 244

- 246 ; 17, pp. 1

- 2 T46518

- 27 PW

- 3 2. 31 Ref. 7, pp. 151, 229

- 231 ; 17, pp. 1

- 2 T46518

- 29 PW

- 4 2. 31 Ref. 7, pp. 151, 235

- 237 ; 17, pp. 1

- 2 4844

- 7 PW

- 8 2. 31 Ref. 7, pp. 394, 399

- 40 2 ; 17, pp. 1

- 2 Total 612

. 5 5 Not Applicable Sum of Population Served by Level I Wells: 612.55 Sum of Population Served by Level I Wells x 10: 6,125.50 Level I Concentrations Factor Value: 6,125.50

3.3.2.3 Level II Concentrations

Not Scored35 Targets

3.3.2.4 Potential Contamination
Because on-line records appeared inconsistent, the target data obtained during the 2010 ESI is being used for the scoring purposes; it considers first-hand field ac counts cross-referenced with information obtained from the MABLE/Geocorr2K database. According to the MABLE/Geocorr2K database consulted during the 2010 ESI, there were 30 residents between 0- and 0.25-mile radius of the KPB facility; 427 residents between 0.25- and 0.5-mile radius; 830 residents between 0.5- and 1-mile radius; 5,591 residents between
1 - and 2-mile radius; 1,783 residents between 2- and 3-mile radius; and 263 residents between 3- and 4- mile radius. However, most of the homes within about 2 miles are connected to the city water distribution system (Ref. 4, pp. 44 ).
The population within 4 miles of the source at Building 1 (8,925) is 844 more than the population served by the York public water supply system (8,081). The York public water supply is a blended water system (Ref. 28, p. 1); therefore, the population served is divided by the number of active PWS wells (11) for a population of about 735 per well. No homes within 0.25 mile of the site were identified as served by private well s . The number of private wells within 1 mile has been estimated from review of the aerial photograph and excludes wells counted as actual contamination (Level I) targe ts. NDNR registration
records indicate seven domestic wells are located between 1 and 2 miles of the site, and 16 are between 2 and 3 miles ( Ref

s . 7, pp. 31

- 35 , 134

- 140 ; 22 ). The number of private wells is multiplied by the county average of 2. 31 (Ref. 1 7) persons per household and is added to the population of 735 per public water supply well. Specific individual s considered for scoring purposes and associated references are included
in Table 12

. The potential contamination (PC) target value was determined using Table 3-12 from the HRS Rule. The distance-weighted population values were determined using the distance category for non-karst aquifers. The PC target value is the total distance-weighted population value divided by 10 and rounded to the nearest integer. Therefore, the PC target value is 191.5. Table 12 shows how the PC target value was
determined.36 Targets Distance Category (miles) Table 1 2 : Distance

- Weighted Population For The Ground W ater Pathway

Wells Approximate Population a Distance

- Weighted Population Value ( Ref. 1, Table 3

- 12) 0 to 1⁄4 Greater than 1⁄4 to 1⁄2 Greater than 1⁄2 to 1 Greater than 1 to 2 Greater than 2 to 3 Greater than 3 to 4 0 2 Public 4 Public + 8 Residential 4 Public + 7 Residential

1 Public + 16 Private Private a 0 1470 2,9 40 + 18 = 2, 9 58 2,9 40 + 16 = 2, 95 6

73 5+ 36 = 771 2 63 0 1,013 523 294 68 13 Totals NA 1,911 Potential Contamination (PC) Value = Distance

- Weighted Population/10 191.1
Sources for the table: Ref s

. 1, Table 3

- 12; 17, pp. 1

- 2 ; 19, pp. 1

- 2 Notes:

a Because no public supply wells supply population between 3

- and 4

- mile radius, 2010 population with in this distance ring of 2 63 has been used for scoring purposes (Ref. 4, p. 44)

.

3.3.3 RESOURCES
This factor was assigned a score of 5 because of known ground water use as a resource in the area near
the site. Ground water in the area is used for crop irrigation (Ref s

. 1, Section 3.3.3; 14, p. 1 , 5 ; 22)

.

Resources Factor Value: 5

3.3.4 WELLHEAD PROTECTION AREA
The City of York’s wellhead protection area covers a bout 8 square m iles and includes the entire
PCE/TCE Northeast Contamination site . As noted in Table 2, there is no known liner impeding release
from Source 1 to the York public supply well listed in the Safe Drinking Water Information System (SDWIS), Ther efore, a wellhead protection factor value of 20 has been assigned (Ref. 4, p. 39 ; 29, p. 12). Figure 5 includes boundaries of the concerned wellhead protection area ; the registered wells in the figure are depicted with or without spacing protection, which is minimum well spacing (distance) for registered wells under separate ownership. Governed by the Nebraska statute 46- 651, spacing of water wells does not allow irrigation or industrial water well or water well of any other public water supplier drilled within 1,000 feet of registered irriga tion or industrial water well (Ref. 22 ; 29, pp. 12, 22).

Wellhead Protection Area Factor Value: 20 (Ref. 1, Section 3.3.4)