HRS DOCUMENTATION RECORD COVER SHEET

Name of Site: Vienna Wells

EPA ID No.: MON000705803

Contact Persons

EPA Contact : Michelle Quick U.S. Environmental Protection Agency, Region 7 901 North 5th Street Kansas City, Kansas 66101 (913) 551-7335

Site Investigation: Missouri Depa rtment of Natural Resources (MDNR)

Documentation Record: Kumud Pyakuryal, Tetra Tech EM Inc.

Pathways, Components, or Threats Not Scored
Soil exposure, surface water migration, and air migration pathways were not completed, because associated pathway scores will have no effect on the NPL listing.HRS DOCUMENTATION RECORD

Name of Site: Vienna Wells EPA Region: 7 Date Prepared: March 2010 Street Address of Site*: 545-547 N. Chestnut Street, Vienna, Missouri 65582
City, County, State: Vienna, Maries County, Missouri 65582 General Location in the State: The site is locat ed on a low ridge between the Gasconade and Maries River valleys (Ref. 4, p. 4).
Topographic Map: The location of site is shown on the Vienna, Missouri, Quadrangle, U.S. Geological Survey, 7.5-Minute Series Topographic Map (Ref. 3, p. 1).
Latitude*: 38o11’22.55”North (R ef. 3, p. 1) (see Figure 1)
Longitude*: 91o56’38.97” West (R ef. 3, p. 1) (see Figure 1)
The latitude and longitude listed above specify the approximate location of the former Langenberg Hat Company facility. Figure 1 shows the site location.

Scores Ground Water Migration Pathway 100.00 Surface Water Migration Pathway 0 Soil Exposure Pathway 0 Air Migration Pathway 0 HRS SITE SCORE 50.00

Note:
*The street address coordinates, and contaminant lo cations presented in this HRS documentation record identify the general area in which the site is located . They represent one or more locations EPA consider 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 releases, 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 repr esent 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 may be re fined as more information is developed as to where the contamination has come to be located.

12 WORKSHEET FOR COMPUTING HRS SITE SCORE

S S 2
1. Ground Water Migration Pathway Score (S gw ) (from Table 3-1, line 13) 100 10,000

2a. Surface Water Overland/Flood Migration Component (from Table 4-1, line 30) Not Scored
2b. Ground Water to Surface Water Migration Component (from Table 4-25, line 28) 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. Total of S gw 2 + S sw 2 + S s 2 + S a 2 10,000
6. HRS Site Score Divide the value on line 5 by 4 and take the square root 50.00TABLE 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 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 10,000 5. Hazardous Waste Quantity a 100 6. Waste Characteristics 100 32 Targets: 7. Nearest Well 50 50 8. Population: 8a. Level I Concentrations b 6,280 8b. Level II Concentrations b Not Scored 8c. Potential Contamination b 2.8 8d. Population (lines 8a + 8b + 8c) b 6,282.80 9. Resources 5 Not Scored 10. Wellhead Protection Area 20 Not Scored 11. Targets (lines 7 + 8d + 9 + 10) b 6,332.80 GROUND WATER MIGRATION SOURCE FOR AN AQUIFER 12. Aquifer Source [(lines 3 x 6 x 11)/82,500] c 100 100 GROUND WATER MIGRATION PATHWAY SCORE 13. Pathway Score (S gw ), (highest value from line 12 for all aquifers evaluated) c 100 100

Notes:

a Maximum value applies to wa ste characteristics category b Maximum value not applicable

c Do not round to nearest integer

3FIGURE 1.–SOIL SAMPLE LOCATION MAP4SourceCharacterizationFIGURE 2.–4-MILE TARGET DISTANCE MAP5SourceCharacterizationREFERENCES

Reference Number Description of the Reference

1 U.S. Environmental Protection Agency (EPA). Hazard Ranking System, 40 CFR Part 300, Appendix A, 55 FR 51533. December 14, 1990. Available Online at http://www.epa.gov/superfund/sites/nplhrsres/index.htm . Excerpt. 1 page. [Note: A complete copy of the rule is available from the Region 7 Docket upon request.]
2 EPA. Superfund Chemical Data Matrix. June 1996. Excerpt. 8 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). Vienna, Missouri Quadrangle, Missouri, 7.5-Minute Series (topographic) . 1981. 1 page.
4 Missouri Department of Natural Resources (MDNR). 2009. Site Inspection Report for Vienna Wells Site, Maries County, Missour i. March 31. Excerpt. 48 pages.
5 MDNR. 2008. Appendix D of the MDNR Site Inspection Report (Reference 4): Sampling Documentation in support of the Site Inspection Report for Vienna Wells Site. March 2009. 278 pages.
6 New Hampshire Department of Environmen tal Services (NHDES). Environmental Fact Sheet. 1, 2-Dichloroethene: Health Information Summary. 2005. 2 pages.
7 EPA. 2009. Envirofacts Multisystem Database Query Results of Facilities in Near the Langenberg Hat Company facility. On-line Address: http://www.epa.gov/myenvmap/map.html. Ac cessed on September 10. 3 pages.
8 Miller, D. and J. Vandike. 1997. Ground water Resources of Missouri. Missouri State Water Plan Series Volume II. Excerpt. 28 pages.
9 MDNR. 2007. Missouri Environmental Geology Atlas (MEGA). Excerpt. 4 pages.
10 MDNR. 2009. Water Resources Website. On-line address: http://www.dnr.mo.gov/env/wrc/index.html . September 11. 3 pages.
11 MDNR. 2008. Appendix E of the MDNR Site Inspection Report (Reference 4): References for the 2008 MDNR Site Inspec tion Report. March 2009. 252 pages.
12 EPA. 2009. Safe Drinking Water Information System (SDWIS) for Maries County, Missouri: http://oaspub.epa.gov/enviro/sdw_query_v2.ge t_list?wsys_name=&fac_search=fac_begi nning&fac_county=MARIES&pop_serv= 500&pop_serv=3300&pop_serv=10000&pop_ serv=100000&pop_serv=100001&sys_status=ac tive&pop_serv=&wsys_id=&fac_state= MO&last_fac_name=&page=1&que ry_results=&total_rows_found=

. September 21. 2 pages.

6REFERENCES (Continued)

7 Source Characterization

Reference Number Description of the Reference

13 U.S. Census Bureau. 2009. Fact sheet for Vienna, Maries, Missouri. On-line Address: http://factfinder.census.gov/servlet/SAFFF acts?_event=Search&geo_id=05000US29125 &_geoContext=01000US|04000US29|05000U S29125&_street=&_county=Vienna+City &_cityTown=Vienna+City&_state=04000U S29&_zip=&_lang=en&_sse=on&ActiveGe oDiv=geoSelect&_useEV=&pctxt=fph&pgs l=050&_submenuId=factsheet_1&ds_name= DEC_2000_SAFF&_ci_nbr=null& qr_name=null®=null:null&_keyword=&_industry= . Accessed on December 8. 2 pages.
14 EPA. 2004. Understanding the Safe Dr inking Water Act. On-line Address: http://www.epa.gov/safewater/sdwa/pdfs/fs_30ann_sdwa_web.pdf . June. 4 pages.
15 EPA. 2009. Envirofacts Multisystem Database Query Results of Facilities in Near the Langenberg Hat Company facility. On-line Address: http://iaspub.epa.gov/enviro/fii_query_dtl.disp_program_facility?p_registry_id=1100144 11163 . Accessed on December 28. 1 page.
16 EPA. 1996. EPA Gas Chromatographic/ Mass Spectrometric Method 8260B: Volatile Organic Compounds by Gas Chromatography /Mass Spectrometry (GC/MS). December. 86 pages.
17 EPA. 2003. EPA Region VII Expedite d RCRA Settlement Agreement (Respondent: Feeler Lumber Company). Signed March 2003. 13 pages.SITE SUMMARY
The Vienna Wells site is located in Vienna, Maries County, Missouri. Based on the 2000 census the city population is 628, with an average household size of 2.11 pe rsons. It is a small rural city with a total of 297 housing units within an approximately 1.1 square mil es area. The City of Vienna is located near the center of the county, and the site coordinates for th e Vienna Wells site are 38°11’22.55 North latitude and 91°56’38.97” West longitude (Ref. 3, p. 1; 13, p. 1).

The Vienna Wells site is compo sed of documented releases of haza rdous substances, mainly volatile organic compound (VOC) tetrachloroethene (PCE) in to two wells associated with the local public drinking water supply and a source area of VOCs, ma inly PCE, trichloroethene (TCE), and cis-1, 2- dichloroethene, at the former Langenberg Hat Factory facility. The City of Vienna public drinking water well #3 is the primary water source for its 628 resident s; well #1 is currently operating as an emergency standby and supplemental water supply well and well # 2 was taken out of service in 2007 due to aesthetic reasons. However, well #2 continues to be used to monitor the water level of the underlying Ozark Aquifer (Ref. 4, pp. 4, 5, 19). The residents that rely on the city’s public drinking water supply system are subject to Level I actual contamination, as PCE has been detected consistently in well #3,
above one or more HRS health based benchmarks ; it was detected at 6.25 micrograms per liter ( μ g/L or parts per billion [ppb]) and 5.53 μ g/L on November 2008 and February 2009, respectively (Ref. 1, Section 3.3.2.1, 3.3.2.2; Ref. 2, p.6; Ref. 4, p. 40).

In 2007, the Missouri Department of Natural R esources (MDNR) Public Drinking Water Branch requested its Hazardous Waste Program’s Superfund Section Site Assessment Unit to conduct an investigation to determine the source of PCE in Vien na public drinking water well # 3. Routine water monitoring in August 2006 revealed PCE at a level exceeding the U.S. Environmental Protection Agency’s (EPA) Maximum Contaminant Level (MCL) for PCE of 5.0 micrograms per liter ( μ g/L or parts per billion [ppb]). Historically wells #1, #2, and #3 have been associated with the city public water supply. Department records showed wells #1 a nd #2 were sampled for volatile organic compounds (VOCs) on May 20, 1991 and March 22, 1993 with no VOC detections. On June 7, 1994, well #1 was sampled and PCE was detected at 0.9 μ g/L. Well #3 was drilled in 1994 and a sample collected at the time showed no VOCs and it became the primary water well. As the Safe Drinking Water Act (SDWA) mandates all community water systems to prepare and distribute reports about the water they provide, well #3 was next sampled for VOCs in March 1997 when PCE was detected at 0.5 μ g/L. Quarterly monitoring of well #3 since 1998 has shown a trend of in creasing PCE levels (Ref. 4, pp. 14-15; 14, p. 3). The Vienna Wells site was entered into the Compre hensive Environmental Response, Compensation, and

8 Source Characterization9 Source Characterization Liability Information System (CERCLIS) database on November 29, 2007. MDNR completed an Abbreviated Preliminary Assessment (APA) on March 28, 2007 with a recommendation for further action under the Superfund Program (Ref. 4, pp. 3-4).

A suspected source of the PCE is the former hat fact ory, located approximately 160 yards southeast of well # 3. MDNR reportedly suspected that a dry-clean ing agent containing PCE may have been used to clean the felt used in making hats. All three wells as sociated with the Vienna public water supply system are located within one-mile radius of the suspect ed source area (Ref. 4, p. 3). The Langenberg Hat Company operated a hat factory at the site (see Figures 1 and 2) from 1952 until 1996. In 1990, the factory facility was transferred to Top This, Inc. (TTI) but it continued to operate under the Langenberg appellation. TTI manufactured ball caps until the fac ility closed in 1996. TTI and Langenberg dissolved in 1997 and 2000, respectively (Ref. 4, p. 5). The current owner of the facility uses it for storage and plans to use it for restoring vintage cars (Ref. 4, p. 6).

In support of the 2009 Missouri Department of Natura l Resources (MDNR) Site Inspection Report, a total of 22 soil samples were collected to delineate the source area at the former Langenberg Hat Factory facility. PCE up to 65.4 milligrams per kilograms (mg/kg), TCE up to 1.21 mg/kg, and cis-1, 2-dichloroethene up to 0.027 mg/kg were detected in the surficial and in-depth soil samples collected from the source (Ref. 4, pp. 28-29, 33).Source Number: 1

2.2 SOURCE CHARACTERIZATION

2.2.1 SOURCE IDENTIFICATION

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

The Langenberg Hat Company operated a hat factory at the site (see Figures 1 and 2) from 1952. In 1990, the factory facility was transferred to Top This , Inc (TTI) but it continued to operate under the Langenberg appellation. TTI manufactured ball cap s until the facility closed in 1996. TTI and Langenberg legally dissolved in 1997 and 2000, respectively (Ref. 4, p. 5).

The former hat factory is located 160 yards southeast of the contaminated Vienna Well # 3 that serves an estimated 628 residents of Vienna, Missouri; it is suspected of improperly using dry-cleaning agents during its active operation. In addition, one public water supply well and 86 private wells are located within the 4-mile target distance limit (TDL) of the site. The 2008 MDNR SI sampling results documented the presence of PCE, TCE, and cis -1, 2-dichloroethene in Source 1 located at the facility property. Source 1 constitutes contaminated soil locati ons depicted in Figure 1. MDNR determined the
source of contamination in the Vienna area is the former Langenberg Hat Factory, which manufactured hats until 1996; during its operational period solvents were used to maintain th e machinery and to clean fabrics used in the manufacturing process. It is belie ved that historical releases from the hat factory have impacted the groundwater, eventually migrating to the public drinking water wells that serve the city of Vienna, Missouri (Ref. 4, pp. 10, 13; Ref. 5, p. 5).

MDNR conducted three sampling events at the former Langenberg Hat Company site between April 12, 2007 and August 26, 2008 to characterize the s ource. A total of 22 soil samples were submitted for analysis. The 2008 MDNR SI Figures 3 and 4 depi ct all soil sampling locations and select soil results
with elevated levels of associated cont aminants (Ref. 4, pp. 7, 28, 29).

The 2008 MDNR SI Table 1, Appendix B, summarizes th e results for the three so il sampling events used to document Source 1 (Ref. 4, p. 33). Each samp ling event is discussed in detail in subsequent paragraphs:

10 Source CharacterizationSource Number: 1

April 12, 2007 Sampling Event: A track-mounted Geoprobe TM was used to drill borings on the former hat factory property and soil-gas probes were used to screen sampl es for biased sampling. Because no volatile organic compounds (VOC) were detected by th e probe, soil samples were collected at refusal, assumed to be the top of bedrock, from Boring 01 and Boring 07. Boring 09 served as background and was collected at the depth of 6.5 to 7 feet below ground surface (bgs); no VOCs were detected in the background sample. The samples were analyzed by the MDNR Environmental Services Laboratory (Ref. 4, pp. 7-8). Boring 01 was located five feet north of the main facility building (see Ref. 4, p. 28-29), in front of a former loading dock area. A sample wa s collected from Boring 01 at 10 to 11 feet bgs. PCE was detected in this sample at 0.198 milligram per kilogram (mg/kg or parts per million [ppm]) (Ref. 4, p. 8).

April 1, 2008 Sampling Event: During this second round of sampling in support of the MDNR SI, a total of eight subsurface samples was collected at re fusal for each boring. Samples collected at Borings 11, 16, and 17 contained PCE. Boring 11 was placed outside of a loading dock on the north side of the main building; the sample collected at this location was taken from 6.5 to 7.0 feet bgs and contained PCE at 0.00323 mg/kg. Boring 16 was placed in a grassy field located approximately 41 yards northeast of the main building; the sample collected at this location was taken from 7.5 to 8.0 feet bgs and contained PCE at 16.3 mg/kg (Ref. 4, pp. 8, 28-29). It also contained cis -1, 2-dichloroethene, a degradation byproduct of PCE, at an estimated concentration of 0.00454 mg/k g (Ref. 4, pp. 8, 28-29; 6, pp. 1). Boring 17 was placed immediately west of the main building; th e sample collected at this location was taken from 12.5 to 13 feet bgs and contained PCE at 0.0991 mg/kg (Ref. 4, pp. 8, 28-29. 33; 5, pp. 184, 186, 223).

August 26, 2008 Sampling Event: This final round of sampling in support of the MDNR SI focused on the grassy field located approximately 41 yards northeast of the main facility building. A total of eight soil borings were advanced (Soil Borings 19 through 26) during the event. Six of the 10 samples collected contained PCE at levels ranging from 0.00719 mg/kg to 65.4 mg/kg (Ref. 4, pp. 9-10, 28-29). A summary of select sampling data collected in support of the 2008 MDNR SI is presented in Table 1 of the SI report (Ref. 4, p. 33).

2.2.2 HAZARDOUS SUBSTANCES ASSOCIATED WITH THE SOURCE
All Source 1 samples were collected at the facility property (see Figure 1). PC E, TCE, and cis-1, 2 dichloroethene were documented in Source 1 soil samples (See Table 1 below). The results presented from past source soil sampling activities suggest a confirmation of PCE contamination at the site (Ref. 4, pp. 7-9, 28-29). Based on field observations documen ted in the SI sampling report during soil sampling,

11 Source CharacterizationSource Number: 1

background and source samples were collected from simila r tight-brown and red-rocky clay (Ref. 5, p. 13, 225).

Background Samples
All source samples were collected at the facility prop erty (see Figure 1) and further compared with the background. Boring 09 was selected as background sa mple; it was located at the Vienna Baseball Park,
on the western side of Vienna. No VOCs were detected at Boring 09 (Ref. 4, pp. 8, 10, 28, 33 and 48; 5, pp. 13, 40, 41, and 42). Background and contaminat ed sample results are presented in Table 1. Corresponding soil sample locations are presented in Figure 3 and 4 of the 2008 MDNR SI (Ref. 4, pp. 28-29).

The primary soil composition in the vicinity of the Vienna well site is the Gravois-Gatewood Complex. Gravois-Gatewood silt loam is composed of roughly 12 to 80 percent clay with the greater clay percentage at depth; residuum beneath the soil is cher ty silty clay that grades into cherty silty clayey gravel with depth. Based on the well logs in the ar ea, the soil and residuum range in thickness from 5 to 25 feet beneath the site (Ref. 4, p. 11, 36; 11, pp. 6, 10, 16). A thorough review of observations made during field sampling indicated that all samples were collected from tight red and brown clay with some rock fragments; at similar depths; and using the same sampling protocol. Therefore, no noticeable difference in physical composition was found betw een the background and Source 1 samples. The background sample was collected in April 2007 and s ubmitted for analysis using the same field sampling and analysis methods used to sample and analyze sa mples collected from Source 1 (Ref. 5, pp. 5, 6, 13, 183, 222-224, 265-266).

Contaminated Samples

The source hazardous substances are those hazardous substances documented in source soil samples above background levels. As discussed in Secti on 2.2.1 and listed in Table 1, PCE, TCE, and cis -1, 2- dichloroethene were detected in multiple s ource samples collected at Source 1.

Table 1: Laboratory Analytical Result s for Soil Borings 01, 09 (Background), 11, 16, 17, 19, 20, 22, 23, and 24 Soil Boring Number (Laboratory Number) Sample Depth (feet bgs) Date Hazardous Substance Hazardous Substance Concentration (mg/kg)* Reference SB01 (0700117) 10 to 11 4/12/2007 PCE 0.198 Ref. 4, pp. 28-29, 33; 5, pp. 13, 36 SB- 6.5 to 7 4/12/2007 PCE ND(<0.0025) Ref. 4, pp.

12 Source CharacterizationSource Number: 1

Table 1: Laboratory Analytical Result s for Soil Borings 01, 09 (Background), 11, 16, 17, 19, 20, 22, 23, and 24 Soil Boring Number (Laboratory Number) Sample Depth (feet bgs) Date Hazardous Substance Hazardous Substance Concentration (mg/kg)* Reference 09/Background (0700119) TCE cis -1,2-dichloroethene ND(<0.0025) ND(<0.0025) 28-29, 33; 5, pp. 5, 7, 13, 41-42 SB-11 (0801122) 6.5 to 7 4/1/2008 PCE 0.00323 (estimate) Ref. 4, p., 28- 29, 33; 5, pp. 184, 186, 188, 196-198, 222 SB-16 (0801127) 7.5 to 8 4/1/2008 cis -1,2-dichloroethene PCE 0.00454 (estimate) 16.3 Ref. 4, pp. 28- 29, 33; 5, pp. 184, 186, 190, 210-212, 223 SB-17 (0801128) 12.5 to 13 4/1/2008 PCE 0.0991 4, pp. 8, 28-29. 33; 5, pp. 184, 186, 190, 212- 214, 223 SB-19 (0808082) 0.5 to 1 8/26/2008 PCE 0.00719 Ref. 4, p., 33; 5, pp. 225, 227, 229, 237- 240, 265 SB-19 (0808081) 6.5 to 7.5 8/26/2008 PCE TCE 2.39 0.588 (estimate) Ref. 4, pp. 28-29, 33; 5, pp. 225, 227, 229, 235-237, 265 SB-20 (0808083) 0.5 to 1 8/26/2008 PCE 0.0141 Ref. 4, pp. 28-29, 33; 5, pp. 225, 227, 229, 240-242, 265 SB-22 (0808086) 8.5 to 9 8/26/2008 PCE TCE cis -1,2-dichloroethene 0.412 0.598 0.027 Ref. 4, pp. 28-29, 33; 5, pp. 225, 227, 232, 248-250, 266 SB-23 (0808088) 9 to 9.5 8/26/2008 PCE TCE cis -1,2-dichloroethene 65.4 1.21 0.018 Ref. 4, pp. 28-29, 33; 5, pp. 225, 227, 231, 253-255, 266 SB-24 (0808089) 12 to 12.5 8/26/2008 PCE 0.00574 Ref. 4, pp. 28-29, 33; 5, pp. 225, 227, 233, 255-257, 266

Notes:

13 Source CharacterizationSource Number: 1

* Based on the EPA Method 8260B used by the MDNR for the analysis of samples listed in Table 1, the Method Detection Limit (MDL) of the external standard method for PCE, TCE, and cis-1,2-dichloroethene are 0.0026 mg/kg, 0.003 mg/kg, and 0.0027 mg/kg (Ref. 16, pp. 65-68).

2.2.3 HAZARDOUS SUBSTANCES AV AILABLE TO A PATHWAY

Table 2: Hazardous Substan ces Available to a Pathway

Containment Description Containment Factor Value References Gas release to air Not Scored NA Particulate release to air Not Scored NA The containment factor value for the ground water migration pathway was evaluated for Source 1. The containment factor value was determined based on the evidence of hazardous substance migration from Source 1 as documented in existing analytical evidence of hazardous substances in ground water samples from public wells. Source 1 has no liner. Ther efore based on the evidence of a release, 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 Rule (Ref. 1, Section 3.1.2.1). 10 4, pp. 28-29, 33

Release via overland migration and/or flood. 10 NA

2.2.4 HAZARDOUS WASTE QUANTITY

2.4.2.1.1 Hazardous Constituent Quantity

The information available is insuffici ent to adequately determine Tier A, as required in Section 2.4.2.1.1 of the HRS Rule. As a result, the evaluation of H azardous Waste Quantity proceeds to evaluate Tier B, hazardous wastestream quantity (Ref. 1, Section 2.4.2.1.1).

2.4.2.1.2 Hazardous Wastestream Quantity

The information available is insuffici ent to adequately determine Tier B, as required in Section 2.4.2.1.2 of the HRS Rule. As a result, the evaluation of H azardous Waste Quantity proceeds to evaluate Tier C, volume (Ref. 1, Section 2.4.2.1.2).

2.4.2.1.3 Volume

The information available is insuffici ent to adequately determine Tier B, as required in Section 2.4.2.1.3 of the HRS Rule. As a result, the evaluation of the Hazardous Waste Quantity proceeds to evaluate Tier D, Area (Ref. 1, Section 2.4.1.3).

2.4.2.1.4 Area
Soil samples were collected from Source 1, as presented in Table 1 of this documentation record and shown in Figures 3 and 4 of the MDNR SI report (Ref. 4, pp. 28-29). It is not known whether

14 Source CharacterizationSource Number: 1

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 (Ref. 1, Section 2.4.2.1.4).

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

Area Assigned Value: >0

15 Source CharacterizationSource Number: 1

16 Source Characterization 2.4.2.1.5 Source Hazardous Waste Quantity Value
Highest assigned value assigned from Table 2-5:

SUMMARY OF SOURCE DESCRIPTIONS
Table 3: Summary of Sources Descriptions Containment Factor Value by Pathway

Surface Water (SW) Air

Source No. Source Hazardous Waste Quantity Value Source Hazardous Constituent

Quantity Complete?

(Y/N) Ground Water (GW) (Table 3-2) Overland/flood (Table 4-2) GW to SW (Table

3-2) Gas (Table

6-3) Particulate (Table

6-9) 1 >0 No 10 Not Scored Not Scored Not Scored Not Scored

Description of Other Possible Sources
MDNR SI reported that the water system operator of Vienna believed there was a waste water lagoon in the area near Boring 16 at the former hat factory fac ility; however, attempts during the investigation could not locate it (Ref. 4, p. 8). No other possible sources were identified.3.0 GROUND WATER MIGRATION PATHWAY

3.0.1 GENERAL CONSIDERATIONS
Regional Setting
Vienna is situated on a topographi c high between the Gasconade River, located about 2 miles east of the town, and the Maries River, located about 2 miles to the west. Elevations at the town range from about 840 feet above mean sea level (AMSL) to about 900 feet AMSL near the intersection of 8 th and Mill Streets, about 700 feet southwest of the facility. Elevations at the site are about 840 feet AMSL (Ref. 3, p. 1). The topographic divide generally runs north-south through the central part of Vienna
between Main and Mill Street. Elevations at the Ma ries River are about 750 feet AMSL, while elevations at the Gasconade River are about 620 feet AMSL (Ref. 3, p. 1). Both Rivers flow northward. The Maries River flows into the Osage River about 20 miles to the north of Vienna, about 5 miles south of the confluence of the Osage River and the Missouri Rive r. The Gasconade River flows into the Missouri
River about 40 miles northeast of Vienna. Re gional ground water flow in the Vienna area is northeastward, towards the Gasconade River (Ref. 3, p.1; Ref. 9, pp. 1-3). MEGA indicates that the regional groundwater elevations range from about 825 feet AMSL, southwest of Vienna, to about 575 feet AMSL northeast of Vienna (Ref. 9, pp. 1-3).

Regional Geology
Soils in the site area are dominantly silt loams of the Gravois-Gatewood complex. Residuum is cherty, silty clay that grades into cherty, silty clayey gravel (Ref. 11, p. 6). Well logs available in the Missouri Environmental Geology Atlas (MEGA) and the Miss ouri Water Resources Website for the Vienna area indicate that bedrock is typically encountered betwee n about 10 and 25 feet below surface (Ref. 9, p. 1, Ref. 10, p. 2-3). The well log for the city of Vienna well #3 is able to represent geology for the Vienna area (Ref. 10, p. 3).

17 GW - GeneralBedrock Units
The geologic column in a table format below pr esents a summary of the geologic units and rock thicknesses present in the Vienna area.

Age Geologic Unit Regional Average Thickness

(Feet) Vienna PW #3 Well Log Thickness

(Feet) Approximate Elevation at Top of Formation as seen in Vienna PW #3 Well Log (Feet MSL) Occurrence of Unit Reference

Recent Residuum 0-300 25 860 Overlies bedrock Ref. 3, p.1, Ref. 8, pp. 6, 8; Ref. 10, p. 3

Jefferson City Dolomite 200 Not identified in PW # 3 Not identified in PW # 3 Identified in several wells that appear to be located at the highest elevations along the ridge through Vienna. Ref. 8, p. 8; Ref. 10, p. 3

Roubidoux Formation 170 65 835 Uppermost bedrock at city well # 3 and likely at nearby Source 1 (only 65 feet thick at Well # 3) Ref. 8, p. 8; Ref. 10, p. 3 Ordovician

Gasconade Dolomite (Upper and Lower Gasconade Dolomite, and Gunter Sandstone) 320 225 770 Underlies Vienna; uppermost bedrock in Gasconade and Maries River valleys, about 2 miles east and northwest of Vienna, respectively. Ref. 8, pp. 8, 10; Ref. 10, p. 3

Eminence Dolomite 220 260 545 Underlies entire area; only penetrated in city well # 3 Ref. 8, p. 8; Ref. 10, p. 3

Potosi Dolomite 200 290 285 Underlies entire area; only penetrated in city well # 3 Ref. 8, p. 8; Ref. 10, p. 3 Cambrian

St. Francois Confining Unit (Derby-Doerun and Davis Formations) 330 105 -5 Underlies entire area Ref. 8, p. 8; Ref. 10, p. 3

Notes:

MSL Mean sea level

18 GW - GeneralThe Ordovician-aged Jefferson City is the youngest bedr ock unit in the Vienna area. The Jefferson City is typically about 200 feet thick and is predominately a fine to medium crystalline, light brown to tan, silty dolomite (Ref 8, p. 11). The overlying Cotter Do lomite, frequently mapped in combination with the Jefferson City Dolomite, is also about 200 feet thick. Remnants (20 to 45 feet) of the Jefferson City are reported in several well logs and appear to be associat ed with wells at the highest elevations along the ridge where Vienna is situated (Ref 9, p. 3, Ref 10, pp. 1-3). Both the Jefferson City Dolomite and the
Cotter Dolomite Formations have an average thickness of about 200 feet and exhibit similar lithologic and hydrogeologic characteristics that are difficult to differentiate apart. As such, these two unit formations are treated as the same (or one) hydrogeolog ic unit (Ref. 8, p. 8, 11, 12). The underlying
Roubidoux Formation consists of inte rbedded cherty dolomite, sandy dolomite, and sandstone (Ref. 8, p. 11). Based on well logs in MEGA and the logs for the two city wells, the Roubioux Formation in Vienna well #3 is approximately 65 feet thick and in Vienna well #1 it is approximately 115 feet thick. (Ref. 9, p. 1-4, Ref. 10, pp. 1-3).

The Gasconade Dolomite underlies the Roubidoux and o ccurs throughout the area. It is the uppermost bedrock in the Gasconade and Maries River valleys to the east and northeast (Ref. 8, p. 8; Ref. 9, pp. 1-4). The Gasconade is the oldest Ordovician-aged unit in Mi ssouri. It is composed of two units separated by large Cryptozoan algal reef zones that have been silicified to chert (Ref. 8, pp 10-11). The Gunter Member, a persistent sandstone unit, is present at th e base of the Gasconade. The total thickness of the Gasconade in the Vienna area is approximately 225-285 feet (Ref. 8, p. 8; Ref. 9, p. 1-4, Ref. 10, pp. 1-3).

Underlying the Gasconade is the Cambrian-aged Eminence dolomite. The Eminence Dolomite consists of gray to tan, medium- to coarsely-crystalline dolomite with minor nodular chert (Ref. 8, p .9). City well #3 was the only well identified in the Vienna area that penetrated the Eminence. At that location, the Eminence was 260 feet thick (Ref. 10, p. 3).

The Potosi Dolomite, which underlies the Eminence, consists of brownish-gray medium- to fine-grained dolomite. This formation is frequently very “vuggy ”, containing small cavities filled with quartz druse (Ref. 8, p. 9). City well #3 penetrated the Potosi . The total thickness of Potosi in this location was 290 feet (Ref. 10, p. 3).

Underlying the Potosi is the St. Francois Confining Unit, which consists of the Derby-Doerun Dolomite and Davis Formation (Ref. 8, pp. 8-9). The St. Fr ancois Confining Unit is about 330 feet thick and consists of shales, siltstones and dolomites. The Derby-Doerun is an argillaceous dolomite which was partially penetrated in the Vienna city well #3, wher e 105 feet of the unit was encountered (Ref. 10, p. 3).

19 GW - GeneralThe Cambrian Bonneterre formation underlies the Davis formation and is a medium to fine-grained dolomite that locally can be a limestone. The lower part is increasingly sandy and has a gradational contact with the underlying Lamotte sandstone (Ref. 8, p. 9). The Bonneterre has an average thickness of 350 feet (Ref. 8, p. 8). The Lamotte Sandstone is the oldest sedimentary rock formation in the Salem Plateau (Ref 8, p. 7); however, it was predominan tly deposited around the St. Francois Mountains. It is thin or absent in the Phelps and Crawford Counties (R ef. 8, pp. 6, 7), east of Vienna; consequently, it is probably not present in the Vienna area. Where prese nt, the Lamotte is predominantly a quartzose sand, but grades laterally to an arkosic sandstone or conglom erate. It varies in color from light gray to dark brown or red. The Lamotte ranges in thickness from a bout 100 feet, along the margins of the St Francois Mountains, to over 300 feet in the western and sout hern parts of the Salem Plateau. The Lamotte unconformably overlies Precambrian basement rocks, and where it is missing, the younger Cambrian deposits would unconformably overlie the Precambrian (R ef. 8, pp. 7-8). According to the Vienna city well logs #1 and #3, neither of the wells penetrated the Cambrian Bonnetere a nd Lamotte Sandstone Units (Ref. 10, p. 2-3).

Ground Water Migration Pathway Description

A combination of public and private wells provides drinking water for residents living in the site area. The city of Vienna has three public drinking water wells drawing water from the Ozark Aquifer. Only Wells # 1 and # 3 are currently in service, with We ll # 3 serving as the primary water source and Well # 1 serving as an emergency standby. Well # 2 was taken out of service in 2007 due to aesthetic concerns. It is currently used by the MDNR’s Water Resource cente r to monitor the water level of the Ozark Aquifer (Ref. 4, p. 12; Ref. 11, p. 31).

MDNR’s Public Drinking Water Branch (PDWB) and DGLS databases contain records for four public
wells within four miles of the Vienna Wells Site. The four wells are the three public wells associated with Vienna and the Maries County PWSD #1 – North well. The 2008 Census of Missouri Public Water Systems lists the population served by the Vienna public wells as 611 (Ref. 11, p. 85). However, the city water system operator provided the figure of 628 people served (Ref. 4, p. 12; 11, p. 24). Therefore, 628 has been used for the scoring purposes of this documentation record.

Maries County PWSD #1 North well is located 3.3 mil es south of Well #3. It was drilled in 1997 to a depth of 1,000 feet. It draws from the Ozark Aquife r (Ref. 11, p. 252). According to the Census of Missouri Public Water Systems - 2008, it serves 400 pe ople (Ref. 11, p. 86), however, the department’s PDWB states that in late 2008 the population served was changed to 250 (Ref. 11, p. 87). VOC samples

20 GW - Generalare collected every three years from this well and historically have b een non-detect. Figure 1 in Appendix
A of the MDNR SI identifies the location of this we ll in relation to the Vienna Public Wells (Ref. 4, p. 26). All four wells draw from the Ozark Aquifer (Ref. 4, p. 12).

Aquifer/Stratum Name: Ozark Aquifer
The site lies within the Salem Plateau portion of the Ozarks Plateau physiographic province. The Ozark Aquifer consists of a sequence of Ordovician and Uppe r Cambrian dolomites, cherty dolomites, and sands that rare typically about 800 to 1,00 feet thick (Ref. 8, p.19). In the Vienna area, about 670 feet in city
well #1 and 865 feet in well #3 of the Ozark aquifer is present (Ref. 8, p. 8, Ref. 9, p. 1-4, Ref. 10 pp. 1- 3). The uppermost bedrock unit is the Ordovician-aged Cotter and Jefferson City Dolomite (Ref. 8, p. 11; Ref 10, p. 2-3). However, well logs available in the Missouri Environmental Geology Atlas (MEGA) indicate the Jefferson City Dolomite is only about 45 feet thick, where present, in the Vienna area (Ref. 10, p. 2). The Ordovician Roubidoux Formation is pr esent below the Jefferson City, and consists in the range of 65 to 120 feet of interbedded cherty dolomite, sandy dolomite, and sandstone (Ref. 10, pp. 2, 3). The Gasconade Dolomite is logged at about 225 to 300 feet thick in the area and underlies the Roubidoux and forms the base of the Ordovician rocks (Ref. 10, pp. 2-3). The underlying Cambrian-aged Eminence and Potosi are also part of the Ozark Aquifer (Ref. 8, p. 8).

The MDNR well logs indicate that most of the olde r private wells were completed in the Roubidoux, while wells for the Courthouse and High School, lo cated about 0.25 mile south of Source 1, were completed in the Gasconade. Two of the municipa l wells are included in MEGA and well logs are available at MDNR’s Water Resources website (Ref. 10, pp. 1-3). Vienna city well # 1 is 670 feet deep. It cased into the Gasconade at a depth of 356 feet bgs, and is an open-hole completion in the Gasconade and Eminence Dolomites of the Ozark Aquifer (Ref. 10, p. 2). Vienna city well # 3 is 970 feet deep and was cased into the top of the Eminence at 321 feet bgs (Ref. 10, p. 3). This well penetrated about 260 feet of the Eminence, encountering the underlying Potosi Dolomite at 575 feet bgs, and encountered the Derby Doerun Dolomite at 865 feet bgs (Ref. 10, p. 3).

The Ozark Aquifer is the most important aquifer in th e Salem Plateau (Ref. 8, pp. 7-8). Water quality is generally good. The Roubidoux and Gasconade typica lly yield about 10 to 70 gallons per minute (gpm), while the Potosi yields 25 to 600 gpm (Ref. 8, pp.13-14). MEGA indicates that regional ground water generally flows east or northeast to the Gasconade River, about 1.75 miles east of the site (Ref. 3, p.1; Ref. 9, p. 3). The hydraulic conductivity of the Ozark Aquifer ranges from 1 X 10 -4 to 1 X 10 -5 centimeters per second (cm/sec) (Ref. 11, p. 7). MEGA indicates a cave density of less than 60 for

21 GW - General22 GW - General Maries County; however, the closest sinkhole identified in MEGA is about 9 miles to the south (Ref. 9, p. 4). The site lies within a karst setting (Ref. 11, p. 8).

SUMMARY OF AQUIFER(S) BEING EVALUATED
Table 4: Summary of Aquifer(s) Being Evaluated

Aquifer

No. Aquifer Name Is Aquifer Interconnected with Upper Aquifer within

2 miles? (Y/N/NA) Is Aquifer Continuous within 4-mile TDL? (Y/N) Is Aquifer Karst? (Y/N)
1 Aquifer Ozark (Jefferson City Dolomite, Roubidoux Formation, Gasconade Dolomite (including Gunter Sandstone Member), Eminence Dolomite, and Potosi Dolomite) NA Y Y

Underlying the Ozark aquifer are the Derby-Doe Run Dolomite and Davis Formation. These units have lower permeability and are referred to as the St. Fran cois confining unit. The St. Francois aquifer underlies these less permeable units and consists of the Bonneterre Dolomite and, where present, the Lamotte Sandstones (Ref. 8, p. 8). The Derby-Doerun Dolomite, encountered in the Vienna city well # 3, and the underlying Davis Formation form the St. Francois Confining Unit separating the Ozark Aquifer from the underlying St. Francois Aquifer. The unde rlying St. Francois Aquifer is not generally used where the prolific Ozark Aquifer is present (Ref. 8, p. 15).23 GW – Likelihood of Release 3.1 LIKELIHOOD OF RELEASE

3.1.1 OBSERVED RELEASE
Aquifer Being Evaluated: Ozark

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 subs tance 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 analys is. 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 potential influence from the site. To establish an observed release for this site, contaminati on in Vienna Well # 3 over time extending from 1991 through 2008 was considered. Review of current a nd historical data indicated Well # 3 did not contain PCE in 1994, but its March 1997 sampling for VOCs indicated PCE was detected at 0.5 μ g/L (Ref. 4, p. 17; 11, pp. 30, 108-113). Follow-up sampling from November 1997 and February 1998 reported PCE
at 0.7 μ g/L and 0.8 μ g/L, respectively (Ref. 11, pp. 115, 117). Subsequently, Well # 3 was required by MDNR’s Public Drinking Water Branch (PDWB) to begin quarterly monitoring for VOCs in 1998. As such, data from Well # 3 will be used to document both background and release samples. For scoring purposes, 0.8 μ g/L will be used for background PCE.

Table 5: Select Backgro und Ground Water Samples Collected by MDNR’s Public Drinking Water Branch

Sample ID Total Depth (below ground surface) Date Sampled Location Description References
94-F440 970 feet 10/13/94 Vienna Well # 3 Ref. 11, pp. 29, 108-110
97-B841 970 feet 03/03/97 Vienna Well # 3 Ref. 11, pp. 29, 112-113
97-0629 970 feet 11/10/97 Vienna Well # 3 Ref. 11, pp. 29, 114-115
98-C485 970 feet 02/17/98 Vienna Well # 3 Ref. 11, pp. 29, 116-1724 GW – Likelihood of Release Table 6: Select Background Ground Water Samples Results Collected by MDNR’s Public Drinking Water Branch

Sample ID Hazardous Substance Results Reporting Limit ( μ g/L) References
94-F440 PCE TCE cis -1,2-dichloroethene ND ND ND 0.5 0.5 0.5 Ref. 11, pp. 108-110

97-B841 PCE TCE cis -1,2-dichloroethene 0.5 ND ND 0.5 0.5 0.5 Ref. 11, pp. 112-113

97-0629 PCE TCE cis -1,2-dichloroethene 0.7 ND ND 0.5 0.5 0.5 Ref. 11, pp. 114-115

98-C485 PCE TCE cis -1,2-dichloroethene 0.8 ND ND 0.5 0.5 0.5 Ref. 11, 116-117

Notes:

ND Non Detect μ g/L micrograms per liter

Contaminated Samples
Sampling in support of the MDNR SI included a collec tion of private drinking water wells in the site vicinity and from the Vienna public wells and water distribution system. Twenty-three private drinking
water wells within one mile radius of the former hat factory were sampled in April 2007; however, no PCE was detected in the private drinking water wells (Ref. 4, pp. 13, 38).

Recent drinking water monitoring sampling conducte d by the PDWB documented PCE in the Vienna wells at concentrations exceeding the Ma ximum Contaminant Level (MCL) of 5.0 μ g/L. Sampling
results for Vienna well # 3 from November 2008 and February 2009 found PCE at 6.25 μ g/L and
5.53 μ g/L, respectively (Ref. 4, p. 20). The MDNR SI sampling in 2007 and 2008 also detected PCE in the public wells. Tables 5 through 9 of the MDNR SI summarize its ground water sampling data (Ref. 4, pp. 37-41). Figure 3, Appendix B, of the 2009 M DNR SI report present figures of sampling locations (Ref. 4, p. 28). All analytical results associated w ith the SI and historical samplings are presented in Appendix E of the SI (Ref. 11, pp. 90-247).25 GW – Likelihood of Release Table 7: Contaminated Ground Water Samples Collected by MDNR’s Public Drinking Water Branch

Sample ID Total Depth (below ground surface) Date Sampled Location Description References
070806020-02 970 feet 09/4/07 Vienna Well # 3 Ref. 11, pp. 29, 220-221
070806020-01 970 feet 09/4/07 Vienna Well # 3 Ref. 11, pp. 29, 222-223
080727754-01 970 feet 09/03/08 Vienna Well # 3 Ref. 11, pp. 29, 238-239
081222687-02 970 feet 02/02/09 Vienna Well # 3 Ref. 11, pp. 29, 246-247
081023549-02 970 feet 11/21/08 Vienna Well # 3 Ref. 11, pp. 29, 242-243

Table 8: Contaminated Ground Water Samples Results

Collected by MDNR’s Public Drinking Water Branch

Sample ID Hazardous Substance Results ( μ g/L) Reporting Limit ( μ g/L) References
070806020-02 PCE 4.23 0.5 Ref. 11, pp., 220-221
070806020-01 PCE 4.47 0.5 Ref. 11, pp., 222-223
080727754-01 PCE 4.69 0.5 Ref. 11, pp., 238-239
081222687-02 PCE 5.53 0.5 Ref. 11, pp., 246-247
081023549-02 PCE 6.25 0.5 Ref. 11, pp., 242-24326 GW – Likelihood of Release Level I Sample (municipal well)
Samples 081222687-02 and 081023549-02 collected from Vienna public drinking water well # 3 and
listed in Table 9 contained PCE at concentration above its maximu m contaminant level (MCL) of 5 μ g/L and above the PCE cancer risk screening concentration (CR) of 1.6 μ g/L (Ref. 2, pp. 5-6). Samples 070806020-02, 070806020-01, and 080727754-01 collected from Vienna Well # 3 and listed in
Table 9 contained PCE at concen trations above the CR of 1.6 μ g/L. These samples met the observed release and Level I concentration criteria (Ref. 1, Table 2-3, Table 3-10, and Section 2.5).

Municipal Well

Table 9: Municipal Well

Laboratory Sample No. Analyte Results Units Sample Date Well ID References 081023549-02 PCE 6.25 μ g/L 11/21/09 Vienna PW#3 Ref. 4, p. 12; 11, pp. 24, 29, 242-243 070806020-02 PCE 4.23 μ g/L 09/4/07 Vienna PW#3 Ref. 11, pp. 29, 220-221 070806020-01 PCE 4.47 μ g/L 09/4/07 Vienna PW#3 Ref. 11, pp. 29, 222-223 080727754-01 PCE 4.69 μ g/L 09/03/08 Vienna PW#3 Ref. 11, pp. 29, 238-239 081222687-02 PCE 5.53 μ g/L 02/02/09 Vienna PW#3 Ref. 11, pp. 29, 246-247Attribution
PCE, TCE, and cis -1, 2-dichloroethene were documented in the contaminated soils (Source 1) at the former Hat factory (see analytical data evidence de picted in Tables 1 of this documentation record) (Ref. 4, pp. 5-10).

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 descr ibed in Section 2.2, Source 1 also contained PCE degradation products TCE and cis – 1,2-dichloroethene. Review of current and historical data indicated Well # 3 did not contain PCE in 1994, but its March 1997 sampling for VOCs indicated PCE was
detected at 0.5 μ g/L (Ref. 4, p. 17; 11, pp. 30, 108-113). Follow-up sampling from November 1997 and February 1998 reported PCE at 0.7 μ g/L and 0.8 μ g/L, respectively (Ref. 11, pp. 115, 117). Quarterly monitoring of well #3 since 1998 has shown a trend of increasing PCE levels (Ref. 4, pp. 14-15). A query of facilities near the former Langenberg Hat f acility found no other source (Ref. 7, pp. 1-3).

Based on the review of the EPA EnviroMapper database, no other known VOC-related manufacturing facilities were identified within Vienna, Missouri. The nearest Toxic Release Inventory (TRI) facility identified in the database is Feeler Lumber Compan y, which is located approximately 1,200 yards from the former hat manufacturing facility (Ref. 15, p. 1; Re f. 17). The other nearest TRI facility identified in the database is Kingsford Manufacturing Company (K MC), which is located approximately 12 miles east/northeast of the Langenberg Hat Company facility. Regional ground water flow in the Vienna area is northeastward, towards the Gasconade River (Ref. 3, pp.1, Ref. 9, pp. 1-3). Further, the most recent 10 years of reported data for KMC does not include PCE, TCE, or cis -1, 2-dichloroethene (Ref. 7, pp. 1-2).

Hazardous Substances Released : PCE

Ground Water Observed Rele ase Factor Value: 550

3.1.2 POTENTIAL TO RELEASE

Not Evaluated

27 GW – Likelihood of Release3.2 WASTE CHARACTERISTICS

3.2.1 TOXICITY/MOBILITY
Table 10: Toxicity/Mobility

Hazardous Substance Source No. Toxicity Factor Value Mobility Factor Value Does Haz. Substance Meet Observed Release?

(Y/N) Toxicity/ Mobility (Table 3-9) Reference PCE TCE cis -1,2-dichloroethene 1 100 10,000 100 1 1 1 Yes No No 100 10,000 100 2, pp. 5-6 2, pp. 7-8 2, pp. 3-4
Toxicity/Mobility Factor Value: 10,000 (Table 3-9)

3.2.2 HAZARDOUS WASTE QUANTITY

Table 11: Hazardous Waste Quantity Value
Source No. Source Type Source Hazardous Waste Quantity 1 Contaminated Soils > 0

The hazardous constituent quantity for Source 1 is not adequately determined. Its source HWQ is undetermined, but greater than zero. As specified in Re ference 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 concentra tions (Ref. 1, Section 2.4.2.2).

Sum of Values: > 0 Hazardous Waste Quantity Factor Value: 100 (Table 2-6)

28 GW – Waste Characteristics29 GW – Waste Characteristics 3.2.3 WASTE CHARACTERISTICS FACTOR CATEGORY VALUE
As specified in the HRS Rule (Ref. 1, Section 3.2. 3), the Hazardous Waste Quantity Factor Value of 100 was multiplied by the highest toxicity/mobility value of 10,000 for TCE, resulting in a product of 1,000,000 (1.0E+06). Based on this product, a w aste characteristics factor value (WCFV) of 32 was assigned from Table 2-7 of the HRS Rule (Ref.1, Section 2.4.3.1).

Toxicity/Mobility Factor Value: 10,000 Hazardous Waste Quantity Factor Value: 100

Toxicity/Mobility Factor Value X Hazardous Waste Quantity Factor Value: 1,000,000 Waste Characteristics Factor Category Value: 32 (Table 2-7)3.3 TARGETS

3.3.1 NEAREST WELL

Well ID: Vienna Well # 3 Level of Contamination (I, II, or potential): I As documented in Section 3.1.1 above, there are numer ous samples containing PCE at concentrations that both meet the observed release criteria and exceed a health-based benchmark (the MCL and/or CR). 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 (Table 3-11)
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 concen trations that meet the observed release criteria (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 abov e an HRS health based benchmark.

30 GW – Targets3.3.2.2 Level I Concentrations (concentrations a ssociated with Level I targets are presented in Section 3.1.1)
The concentrations of PCE in the samples 0810 23549-02, 070806020-02, 070806020-01, 080727754-01, and 081222687-02 below are above the HRS health based benchmark used for comparison and are documented in Section 3.1.1. Sample 081023549-02 and 081222687-02 from Vienna public drinking
water well # 3 and listed in Table 9 contained PCE at concentration above its maximum contaminant level (MCL) of 5 μ g/L and above the PCE cancer risk screening concentration (CR) of 1.6 μ g/L (Ref. 2, pp. 5- 6). These samples met the observed release and Level I c oncentration criteria (Ref. 1, Table 2-3, Table 3- 10, and Section 2.5; Ref. 11, p. 31).

Table 12: Level I Targets Laboratory Sample No. Well ID Population Reference 081023549-02 070806020-02 070806020-01 080727754-01 081222687-02 Vienna PW #3 628 Ref. 11, pp. 24, 31

Sum of Population Served by Level I Wells: 628 Sum of Population Served by Level I Wells x 10: 6,280.00 Level I Concentrations Factor Value: 6,280.00

3.3.2.3 Level II Concentrations`

Not Scored
Sum of Population Served by Level II Wells: 0 Level II Concentrations Factor Value: 0

3.3.2.4 Potential Contamination
The number of people served per private well was de termined by multiplying the average household size of 2.51 persons for Maries County by the number of we lls (Ref. 4, p. 13; 11, p. 88). The DGLS database
contains records of 86 domestic wells within a 4-mile radius. The domestic drinking water well on record nearest to the site is located approximately 0.2 mile . In addition, there were 3 private wells between 0.25 and 0.5 mile; 4 private wells between 0.5 and 1 mile; 15 private wells between 1 and 2 miles; 32 private wells between 2 and 3 miles; and 31 privat e wells between 3 and 4 miles (Ref. 11, pp. 6, 10, 12-15).

31 GW – Targets32 GW – Targets Table 13: Distance-Weighted Popul ation For The Groundwater Pathway Recommended Scoring Distance Category (miles) Private Wells Population Distance-Weighted Population Value (HRS Table 3-12) 0 to 0.25 0.25 to 0.5 0.5 to 1 1 to 2 2 to 3 3 to 4 1 3 4 15 32 31 3 8 10 38 80 78 4 2 1 10 7 4 Totals 86 217 28 Potential Contamination (PC) Value = Distance-Weighted Population/10 2.8 Sources for the table: Ref. 4, p. 13; 11, pp. 88-89

3.3.3 RESOURCES

Not Scored

3.3.4 WELLHEAD PROTECTION AREA
Not Scored: While as noted in Table 2, there is no known liner impeding release from Source 1 and the Vienna public supply well listed in the Safe Drinki ng Water Information System (SDWIS), it was not scored because it did not impact the overall site score (Ref. 12, pp. 1-2).

4.0 SURFACE WATER MIGRATION PATHWAY

Not Scored

5.0 SOIL EXPOSURE PATHWAY

Not Scored

6.0 AIR MIGRATION PATHWAY

Not Scored