Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 1 HAZARD RANKING SYSTE M (HRS) DOCUMENTATION RECORD

REVIEW COVER SHEET

SITE NAME: CIRCLE COURT GROUND WATER PLUME

CONTACT PERSON:

Documentation: Brenda Cook, USEPA 214/665

- 7436 Region 6 NPL Coordinator

Pathway, Components, or Threats Not Evaluated

Surface Water Pathway

The Surface Water Pathway was not scored because the inclusion of this pathway would not impact the listing decision.

Soil Exposure Pathway

The Soil Exposure Pathway was not scored because the inclusion of this pathway would not impact the listing decision.

Air Migration Pathway

The Air Migration Pathway was not scored because the inclusion of this pathway would not impact the listing decisi on.Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 2 SITE DESCRIPTION

The Circle Court Ground Water Plume consists of a contaminated ground water plume originating from unknown sources composed of hazardous substances that released into the Paluxy formation of the Trinity aquifer. The plume location is delineated laterally by the ground water wells that had detections o f trichloroethene (TCE) as listed in Table 1 and depicted in Figure 2.

The City of Willow Park and the City of Hudson Oaks supply water to most homes within the area of the site, except for some of the homes in the area of Russell Road. During the SI

an d ESI efforts

, all domestic and public supply wells located within a quarter mile of the site and the majority of wells within a half mile of the site (Figure 2) were sampled. In addition all public supply wells within one mile of the site were sampled. The location of the plume is shown on Figure 2, and encompasses those well with documented observed releases of
TCE concentration.

The plume location was first indicated by a public water supply well at the Willow Springs Oaks Pump Station located at 11 7 Circle Court in Willow Park, Parker County, Texas, approximately 0.3 mile south of Interstate 20 and 0.3 mile west of Farm to Market Road 5 (Annetta Road) (GW

- 05 on Figure 2). The pump station is in a rural residential area approximately six miles east of the City of Weatherford and is part of the City of Willow Park public water supply (PWS) system. Single

- family properties border the pump station to the south, west and east. A 15

- acre vacant wooded lot borders the pump station to the north.
Three wa ter system service pumps, two ground storage tanks and an elevated storage tank for water are also located at the Willow Springs Oaks Pump Station ( F igure 2).

The City of Willow Park PWS is registered in the TCEQ PWS program and is assigned
identification number 1840027 (Ref. 4, p. 1). The City of Willow Park’s PWS well located at 117 Circle Court in the Hillcrest addition is designated as GW

- 05 in Figure 2. The GW

- 05 well depth is 180 feet (Ref. 5. p. 56, Well 3219201; Ref. 28, p. 7, Line 8; Ref 46 , p. 1)

.

Based on the combined results of the Site Inspection (SI) and Expanded Site Inspection (ESI) sampling events, the location of the plume roughly follows a one half mile stretch of Russell Road, with one detection of TCE further to the east, as listed in Table 1 and depicted in Figure 2. The highest concentration of TCE detected to date was 43 micrograms per liter (μg/L) in a domestic drinking water well, located at 405 Russell Road (Figure 2, GW

- 41, Ref 39 p.5).Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 3 NOTES TO THE READER

The following rules were used when citing references in the Documentation Record:

1. Tracking numbers are assigned by the region to every page of every reference. The tracking number consists of the reference number followed by the page number within
that reference. A t racking number will have a two

- digit number followed by the sequential number (for example, 05 001; 05 002). The tracking numbers are cited for all
references.

2. The State predecessor agencies: Texas Natural Resource Conservation Commission (TNRCC), Texas W ater Quality Board (TWQB), Texas Department of Water Resources (TDWR), Texas Water Commission (TWC), and Texas Air Control Board (TACB), referred to throughout this report are now known as the Texas Commission on Environmental Quality (TCEQ). The new agen cy, TCEQ, became effective September 1, 2002, as mandated under House Bill 2912, Article 18 of the 77 th Regular Legislative
Session

.

3. List of Figures Figure 1 Site Location Map Figure 2 Ground Water Sample Location Map Figure 3 Soil Sample Location Map Figure 4 a Surface Geology Map Figure 4b Regional Geology and Aquifers Figure 5 Drinking W ater Wells by Distance RadiiHazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 4 HRS DOCUMENTATION RECORD

Name of Site: Circle Court Ground W ater Plume

Date Prepared: March 2012

CERCLIS Site ID Number: TXN 000 606 965

Site Specific Identifier: A6V7

Street Address of Site * : 117 Circle Court

.

City, County, State: Willow Park, Parker County, Texas 7 6087

General Location in the State:
The Circle Court Ground W ater Plume ’s location is the center of the plume, which is located approximately 0. 4 mile south of Interstate 20 and 0. 4 mile west of Farm to Market 5 (Annetta Road) (Figure s 1 and 2 ).

Topographic Map: U.S. Geological Survey 7.5 Minute Topographic Map, Lake Weatherford and Anneta Quadrangles.

Latitude * : 32.74 477756 o (North) Longitude : *

- 97.67 976306 o (West)

EPA Region: 6

G round W ater Pathway 100.00 Surface Water Pathway NS ** Soil Exposure Pathway NS ** Air Pathway NS **

HRS SITE SCORE 50.00

*The street address coordinates, and contaminant locations presented in this Hazard Ranking System (HRS) documentation record identify the general area in which the site is located. They represent one or more locations that the U.S.
Environmental Prote ction Agency (EPA) considers to be part of the site based on the screening information EPA used to evaluate the site for National Priority List (NPL) listing. EPA lists national priorities among the known "releases or
threatened releases" of hazardous sub stances; thus, the focus is on the release, not precisely delineated boundaries. A site is defined as where a hazardous substance has been "deposited, stored, placed, or 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 the Comprehensive Environmental Response, Compensation, and Recovery Act (CERCLA). Accordingly, EPA contemplates that the preliminary description of fac ility boundaries at the time of scoring will be refined as more information is developed as to where the contamination has come to be located.

**NS=Not Scored (Pathways were evaluated but not scored because their evaluation would not effect the listing de cision.)

# μ

Circle Court Groundwater Plume Parker County, Texas TXN000606965



## ! ! 

## 2 City of Weatherford Six miles to the west

Circle DriveCircle Court



### Site Center Mikus

Bankhead Fort Worth 180

F a r m T o M a r k e t Lakeshore Stage Coach

20 Access Rd

Mikus 

# §  ̈ ¦

20 

# £ ¤ 180



# U V

5

0 0.25 0.5 0.75 1 1.25 1.5 1.75 2

Miles This map was generated by the Remediation Division of the Texas Commission on Environmental Quality. It is intended for illustrative or informational purposes only, and is not suitable for legal, engineering, or survey purposes. This map does not represent an on-the-ground survey conducted by or under the supervision of a registered professional land surveyor. In cases where property boundaries are shown, it only represents their approximate relative location. No claims are made to the accuracy or completeness of the data or to its suitability for a particular use. For more information concerning this map, contact the Remediation Division at 800-633-9363. 

# Figure 1: Site Location Map

The base data set is UTM Zone 14, Digital Raster Graphics of the Lake Weatherford and Anneta Quadrangles, NAD 1983 Parker CountyKingswood Ranch Oak I 20

Bankhead Mikus

Interstate 20 Crown

Russell Interstate 20 Service Fork Fort Worth Lakeshore

Rob Arroyo

Coates

Big Creek Red Bud
Oak Hill

Dorris Mallory

Southview

FM Road 5 Valley

Diamond Oaks Raven

McKinzie Bluebonnet

Elm Tree

Walters Valley Trail

Austen Oak Park

Megan Live Oak

Clear Fork

Bond

Hunterglenn Red Oak Park

Cottonwood

Woodridge Green Oaks Primrose

Pecan Park

Oak Leaf Beech

Walkers Wintergreen Derek

Steeple Chase Brookview Saddle Brook Hawthorne

Kate Meadowview White Oak I 20 Fort Worth

Interstate 20

Interstate 20 

### GW-01/

GW-02 GW-31

Tackett 

### (Background) 

## ! .

GW-50 

## ! . ! . GW-49



## ! .

GW-03 

## ! . GW-04/DUP GW-25 GW-38/DUP GW-39

GW-42 

## ! .Parker Oaks



### GW-06

GW-41 (Site Center) 

## ! . ! . GW-22

GW-45

GW-34/

/ GW-11/

DUP GW-46 GW-07 / DUP GW-08

DUP GW-35 

## ! .

GW-44

GW-47 

## ! . ! . GW-10

GW-33Oakview 

### GW-37

GW-20 GW-43

DUP GW-09

GW-05

GW-14
GW-12

GW-16/ w



### GW-40 llo oHakO



## ! . ! .

! .

! . ! . ! . GW-19/DUP GW-18 

# Figure 2: Groundwater Sample Location Map 

# μ

Circle Court
Groundwater Plume Parker County, Texas
TXN000606965 ! . ! . GW-36

/ 

## ! .

! . ! . ! . GW-48 Legend

Groundwater Sample Location

Level 1 Concentration

Potential Contamination ! .

! .



## ! .

! . GW-15/GW-32 ( 

## ! . Background)

Parker County Peach



## ! .

! . ! .

This map was generated by the Remediation Division of the Texas Commission on Environmental Quality. It is intended for illustrative or informational purposes only, and is not suitable for legal, engineering, or survey purposes. This map does not represent an 0 0.25 0.5 0.75 1 1.25 1.5 1.75 2 on-the-ground survey conducted by or under the supervision of a registered professional land surveyor. In cases where property
Miles boundaries are shown, it only represents their approximate relative location. No claims are made to the accuracy or completeness of the data or to its suitability for a particular use. For more information The base data set is UTM Zone 14, 0.5 Meter Resolution, Natural Color, NAD 1983 concerning this map, contact the Remediation Division at 800-633-9363. 

### DUP GW-17 

## ! .Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 7 WORKSHEET FOR COMPUTING HRS SITE SCORE

S S 2

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

- 1, line 13)

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

- 1, line 30) NS

2b. Ground Water to Surface Water Migration Component (from Table 4

- 25, line 28) NS

2c. Surface Water Migration Pathway Score (S
sw ) Enter the larger of lines 2a and 2b as the NS

pathway score.

3. Soil Exposure Pathway Score (S
s ) (from Table 5

- 1, line 22) NS

4. Air Migration Pathway Score (S
a ) (from Table 6

- 1, line 12) NS

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 .00

NS = Not ScoredHazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 8 TABLE 3

- 1
GROUND WATER MIGRATION PATHWAY SCORESHEET

Factor Categories and Factors Maximum Value Value Assigned

Likelihood of Release to an Aquifer

1. Observed Release 550

2. Potential to Release 550

2a. Containment 10

2b. Net Precipitation 10

2c. Depth to Aquifer 5

2d. Travel Time 35

2e. Potential to Release

(Lines 2a(2b + 2c + 2d)) 500

3. Likelihood of Release

(Higher of Line 1 and 2e) 550 550

Waste Characteristics

4. Toxicity/Mobility *

5. Hazardous Waste Quantity 1,000

*

6. Waste Characteristics 100

100 18

Targets

7. Nearest Well 50

8. Population: 50

8a. Level I Concentrations **

8b. Level II Concentrations 2,875 .3

** 0

8c. Potential Contamination **

8d. Population (Lines 8a + 8b + 8c) 113

**

9. Resources 2

, 988 .3

5 0

10. Wellhead Protection Area 20 0

11. Targets (Lines 7 + 8d + 9 + 10) ** 3

, 038 .3

Ground Water Migration Score for an Aquifer

12. Aquifer Score

((Lines 3 x 6 x 11)/82,500) 100 100

Ground Water Migration Pathway Score

13. Pathway Score (S gw ), (Highest value from Line 12 for all aquifers evaluated) 100 100Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 9 REFERENCE LISTING

Reference

1. U.S Environmental Protection Agency. Federal Register

– 55 FR Page 51532; Hazard Ranking System; Final Rule, Volume 55, No. 241, December14, 1990. 137

pages. Number Description of the Reference

2. U. S. Environmental Protection Agency. Superfund Chemical Data Matrix (SCDM), Superfund Chemical Data Matrix. Appendix B. November 29 , 2011 . 7 excerpted

pages. A complete version of SCDM is available at:
htt p://www.epa.gov/superfund/sites/npl/hrsres/tools/scdm.htm

3. U.S.G.S 7.5

- Minute Series Topographic Map. Anneta and Lake Weatherford 1959, photorevised 1979. Total Pages:2

4. City of Willow Park , City of Hudson Oaks, City of Willow Park Dyegard, Oak Hill Mobile Home Park East, Available: http://www10.tceq.state. tx.us/iwud/reports/index.cfm?fuseaction=RunWSDataSheetr eport&RequestTimeout=500&pwsid=

. Enter pws

. Accessed September 15

- 16 , 2011.
28 pages.

5. Texas Water Development Board. Groundwater Database Reports. Record of Wells, Parker County. Available: http://www.twdb.state.tx.us/publications/reports/GroundWaterReports/GWDatabaseR eports/Database%20Reports/Parker/R ecord%20of%20Wells.pdf . Accessed February 1, 2011. 72 pages.

6. City of Willow Park. Willow Springs Oaks TCE Removal. March 23, 2006. 1 page.

7. Agency for Toxic Su bstances and Disease Registry. ATSDR ToxFAQs Factsheet:
T richloroethylene CAS # 79

- 01

- 6. Available: http://www.atsdr.cdc.gov/tfacts19.pdf

. July, 2003. Accessed February 22, 2011. 2 pages.

8. Eagle Construction & Environmental Services

, L. P . Water Well Sampling Event.
June 2006. 1 6 pages.

9. U.S. Environmental Protection Agency. Circle Court Groundwater Site Inspection Report. July 2011. 45 pages.

10. Texas Comm ission on Environmental Quality. Site Inspection Field Logbook Notes
from Circle Court Ground W ater. March 9

- 11, 2010. 56 pages.

11. Texas Comm ission on Environmental Quality. Site Investigation Photograph s from
Circle Court Groundwater. March 9

- 11, 2010. 21 pages.Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 10 12. U.S. Environmental Protection Agency. Circle Court Groundwater Expanded Site Inspection Report. August 2011. 36 pages

.

13. Texas Commission on Environmental Quality. Expanded Site Inspection Field Logbook Notes from Circle Court Groundwater. June 22

- 24, 2010. 45 pages.

14. Texas Commission on Environmental Quality. Expanded Site Inspection Photographs
from Circle Court Groundwater. J une 22

- 24, 2010. 9 pages.

15. U.S. Environmental Protection Agency. Evaluating Ground Water Plumes Under the Hazard Ranking System, EPA 540

- F

- 95

- 034, OSWER Publication 9320.8

- 01FS, September 1998. 5 pages.

16. Texas Commission on Environmental Quality. Quali ty Assurance Project Plan for Texas Commission on Environmental Quality

- Preliminary Assessment and Site Inspection Program (Number V

- 96665501

- 0). February 1, 2010. 225 pages.

17. Hazelwood, Gary. Texas Commission on Environmental Quality Project Manager.
He alth and Safety Plan. May 4, 2010. 29 excerpted pages.

18. U.S. Environmental Protection Agency Region 6 Laboratory. Final Analytical Report: Circle Court Groundwater. April 16, 2010. 83 pages

.

19. U.S. Environmental Protection Agency Region 6 Laboratory. Final Analytical Report:
Circle Court Groundwater. May 17 , 2010. 8 pages

.

20. U.S. Environmental Protection Agency Region 6. Contract Laboratory Program Data Review: Circle Court Groundwater, Case 395 51, SDG#MF3FX7. March 26, 2010. 38

pages.

21. U.S. Environmental Protection Agency Region 6. Contract Laboratory Program Data Review: Circle Court Groundwater, Case 39551, SDG#F3FY1. March 24, 2010. 98

pages.

22. U.S. Environmental Protection Agency Region 6. Contract Laboratory Program Data Review: Circle Court Groundwater, Case 39551, SDG#F3FY0. March 26, 2010. 58

pages.

23. U.S. Environmental Protection Agency Region 6. Contract Laboratory Program Data Review: Circle Court Groundwater, Case 39551, SDG#F3FX7. M arch 26, 2010. 303

pages.

24. U.S. Environmental Protection Agency Methodology for Determining Screening Concentration Benchmarks for Trichloroethylene (TCE). Available: http://www.epa.gov/superfund/sites/npl/hrsres/tools/scdm.htm

. February , 2012

. 1 2

pages.Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 11 25. U.S. Environmental Protection Agency Region 6. Contract Laboratory Program Data Review: Circle Court Groundwater, Case 40275, SDG#F3JJ4. July 19, 2010. 109

pages.

26. U .S. Environmental Protection Agency Region 6. Contract Laboratory Program Data Review: Circle Court Groundwater, Case 40275, SDG#F3JK9. July 15, 2010. 29

pages.

27. U.S. Environmental Protection Agency Region 6. Contract Laboratory Program Data
Review: Circ le Court Groundwater, Case 40275, SDG#MF3JJ4. July 29, 2010. 42

pages.

28. Weston Solutions, Inc. Drinking Water Survey Report. May 2010. 129 pages including attachments.

29. Texas Commission on Environmental Quality. Site Inspection Work Plan, Circle Court Groundwater, Prepared in Cooperation With the U.S. Environmental Protection Agency. February 2010. 33 pages.

30. Texas Parks and Wildlife. Natural Subregions of Texas. January 31, 2011.
Available: http://www.tpwd.state.tx.us/publications/pwdpubs/media/pwd_mp_e0100_1070x_08. pdf

. Accessed April 7, 2011. 1 page.

31. Texas Department of Water Resources. Report 269, Occurrence, A vailability, and Chemical Quality of Ground Water in the Cretaceous Aquifers of North

- Central Texas, Volume 1. Phillip L. Nordstrom. April 1982. 67 pages.

32. The University of Texas at Austin, Bureau of Economic Geology. Geologic Atlas of Texas, Dallas Sheet. J. H. McGowen, C. V. Proctor, Jr., W. T. Haenggi, D. F. Reaser, and V. E. Barnes. Gayle Scott Memorial Edition. 1972; revised 1987; reprinted 2000. 12 pages.

33. Texas Water Development Board. Report 345. Aquifers of Texas. John B. Ashworth, Geolog ist and Janie Hopkins, Geologist. November 1995. 69 pages.

34. Upper Trinity Groundwater Conservation District. District Management Plan. Adopted

- 8/16/2010. 156 pages.

35. Freese and Nichols, Inc., Alan Plummer Associates, Inc., CP&Y, Inc., Cooksey Communications, Inc. 2011 Region C Water Plan. October 2010. 123 pages.

36. Warren, Christy. U.S. Environmental Protection Agency, Region 6 Laboratory, Sample Control Center. Email to Brenda Nixon Cook, U.S. Environmental Protection Agency, Region 6 NPL Co ordinator. August 6, 2010. 2 pages.Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 12 37. US Census Bureau. Parker County QuickFacts. Available: http://quickfacts.census.gov/qfd/states/48/48367.html . Accessed September 27 , 2011.
2 pages.

38. Johnson, Lloyd. Texas Commission on Environmental Quality

- Quality Assurance/Technical Support. Interoffice Memorandum: Data Quality Audit and Review. May 4, 2010. 6 pages.

39. Strahl, Ann. Texas Commission on Environmental Quality

- Quality
Assur ance/Technical Support. Interoffice Memorandum: Data Quality Audit and Review. August 12, 2011. 7 pages.

40. Hazelwood, Gary. Texas Commission on Environmental Quality Project Manager. Telephone conversation with City of Willow Park Water Superintendent Dev on Kennedy. August 10, 2011. 1 page.

41. Texas Commission on Environmental Quality. Expanded Site Inspection Work Plan

, Circle Court Groundwater , Prepared in Cooperation With the U.S. Environmental Protection Agency. June 2010. 28 pages.

42. Hazelwood, Gary. Texas Commission on Environmental Quality Project Manager. Telephone conversation with City of Willow Park Water Superintendent Devon Kennedy. November 9, 2011. 1 page.

43. Hazelwood, Gary. Texas Commission on Environmental Quality Project Manager. Telephone conversation with City Hudson Oaks Water Superintendent Ricky King. November 17, 2011. 1 page.

44. Texas Water Development Board. LP

- 212. Delineation Criteria for the Major and Minor Aquifer Maps of Texas. John B. Ashworth, Geologist and Robert R . Flores, Geologist. June 1991. 25 pages.

45. Northern Trinity / Woodbine Aquifer Groundwater Availability Model. Assessment of Groundwater Use in the Northern Trinity Aquifer Due to Urban Growth and Barnett Shale Development. TWDB Contract Number: 060483 0613. R. W. Harden & Associates, Inc. January 2007. 276 pages.

46. Hazelwood, Gary. Texas Commission on Environmental Quality Project Manager. Telephone conversation with City of Willow Park Water Superintendent Devon Kennedy. February 2, 2012. 1 page.

47. Hazelwood, Gary. Texas Commission on Environmental Quality Project Manager. Telephone conversation with City Hudson Oaks Water Superintendent Ricky King. February 2, 2012. 1 page.Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 13 SOURCE DESCRIPTION

2.2 Source Characterization

2.2.1 Source Identification

Number of the source: 1

Name and description of the source: Other

– Ground W ater Plume with No Identified Source

On March 23, 2006, during routine monitoring of the City of Willow Park PWS, a volatile organic compound (VOC), trichloroethe ne (synonym: trichloroethylene, TCE), was detected
at 6. 9 μg/L (Ref. 6, p. 1)

. The detection exceeded the EPA maximum contaminant l evel (MCL) for drinking water of 5 μg/L (Ref. 2, p. 6 ) . Trichloroethene, a colorless organic liquid
with a chloroform

- like odor, is commonly used as a solvent to remove grease from metal parts and is not thought to occur naturally in the environment (Ref. 7 , p. 1). The water sample that exceeded the MCL had been collected from the distribution system point of entry (POE) for the City of Willow Park ’s Circle Court w ell (GW

- 05)

. As a result of the TCE
exceeda nce in raw water at the Circle Court PWS Well, the well was taken out of service on April 1, 2006 (Ref. 6, p. 1) . During subsequent VOC monitoring conducted by the City of Willow Park, a May 4, 2006 sample collected directly from the PWS Circle Court Well had a TCE concentration of 33.9 μg/L. On June 19, 2006, the City of Willow Park installed an inline filter on the impacted well, and the well was subsequently put back into service ( Ref 5

, p. 56

- well number 3219201 ; Ref. 6 , p. 1).

On June 1

- 2 , 2006, as a follow

- up to the TCE detection in the City of Willow Park ’s Circle
Court W ell, the TCEQ sampled nine private wells in the vicinity of the well to determine if the private wells were impacted (Ref. 8, p. 5 ) . The water samples were analyzed for concentrations of VOCs in drinking water by a drinking water certified laboratory. A review of the sample results indica ted the presence of TCE in five of the nine private wells sampled. One of the five wells was a private non

- drinking water well located at the Parker County Airport; the concentration of TCE reported for this well was 12.2 μg/L (Ref. 8 , p p

. 7 and 12

– Barn ett #2 well ).

During the week of March 8, 2010, the TCEQ conducted an SI field sampling event for the
TCE

- contaminated ground water plume site (Ref. 9 ) . The TCEQ collected six soil samples, collected from a depth of 0

- 6 inches, including two background samples

, one field duplicate

, and three soil samples to investigate the most likely potential source locations in the vicinity
of the City of Willow Park ’s Circle Court Well ( Ref. 10, pp. 47, 49, 51, 53, and 55; Ref. 11,

pp. 19

- 21 , Ref. 29 pp.23

- 26 ) . No TCE was detected in any of the soil samples (Ref. 9, p. 41)

. The TCEQ collected 19 ground water samples, including three background samples and three field duplicate samples ( Ref. 9, pp. 16

- 17; Ref. 10, pp. 3

- 43; Ref. 11 , pp. 1

- 19 ) . T hree

aqueous field blank samples were also collected . The locations sampled by TCEQ included five public supply wells and eight private residential wells in the vicinity of the City of
Willow Park ’s Circle Court Well

. Five wells were documented by chemical analysis t o have
TCE levels that met the observed release criteria and exceeded the cancer risk health

- basedHazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 14 benchmark of 0.21 μg/L ( Ref. 2, p. 6 , Ref. 24, pp. 4

- 6 & 12 ) . T hree of those five wells were documented by chemical analysis to have TCE concentrations exce eding the MCL for drinking water of 5 μg/L , as listed in Table 7

. One of the three wells exceeding the MCL

was a non

- drinking water well , but was still used to indicate the plume location in Figure 2

.

The ESI field work was conducted during the week of June 21, 2010 (Ref. 12 , p 16 )

. The TCEQ collected 20 ground water samples, including two background samples

, three field duplicate samples , one public supply well

, and 14 private wells ( Ref. 13; Ref. 14 ) . The well locations were selected to complete the analysis of all known wells located within 0.25 mile
of the City of Willow Park Well ’s Circle Court well , plus additional wells within 0.5 mile of
the City of Willow Park ’s Circle Court Well (Figure 2

– G W

- 05 )

. Three aqueous field blank samples were also collected. Three wells were documented by chemical analysis to have
TCE levels in excess of the cancer risk health

- based benchmark of 0.21 μg/L with one well having been resampled from the SI sampling event ( Ref. 2, p. 6 , Ref. 24, pp. 4

- 6 & 12 )

. O ne of those three wells w as documented by chemical analysis to have a TCE concentration exceeding the MCL for drinking water of 5 μg/L (See Table 8 of th is HRS document). GW

11 and GW

- 33 are samples collected on different dates, from the same well ( Ref. 10, p. 29; Ref. 11, p. 10; Ref. 13, p. 7; Ref. 14, p. 1; Ref. 21, pp. 16,32&57; Ref. 25, pp. 12,31&41; Ref. 28, p. 7 ).

The combined SI and ESI sampling e vents resulted in a total o f seven wells with observed releases (Figure 2, GW04 (Ref. 22, pp. 14,18,26&35) , GW

- 05 ( Ref. 21, pp. 10,28&39 ) , GW

10 (Ref. 21, pp. 15,31&54) , GW

- 12 (Ref. 22, pp. 12,19&29) , GW

- 33 (Ref. 39, pp. 1

- 7) , GW

41 (Ref. 39, pp. 1

- 7) , and GW

- 48 (Ref. 39, pp. 1

- 7) ). Of the seven wells with observed releases, three drinking water wells had documented levels of TCE exceeding the MCL ( Figure 2, GW05 (Ref. 21, pp. 10,28&39) , GW

- 10 (Ref. 21, pp. 15,31&54) , and GW

- 41 (Ref. 39, pp. 1

- 7) ) ; each of these drinking water wells either has a granular activated carbon filtration system or in the case of GW

- 10 a system was provided and later removed at the resident's request

. All three of these wells are located in close proximity of Russell Road and

are screened in the Paluxy formation of the Trinity aquifer , which is the primary drinking water aquifer in the area. Some residences in the vicinity of the site depend on private water
wells screened in the Paluxy formation of the Trinity aquifer as their p rimary drinking water

source. The highest level of TCE was found in a private domestic drinking water well located at 405 Russell Road, Willow Park ( Figure 2, GW

- 41 (Ref. 39, pp. 1

- 7) )

. One non

drinking water well, located at the Parker County Airport, ( Figure 2, GW

- 04 ), was also
documented to have a TCE level exceeding the MCL (Ref. 22, pp. 14,18,26&35)

.

The ground water plume is considered the source, since no surface sources were identified through soil sampling or reconnaissance of nearby areas (Ref. 1; Section 1.1 ; Ref. 9, pp. 37

- 39 ; Ref. 12, p. 30 ).

The ground water plume with no identified source was characterized as the site source based on the following:

**•** The extent of the plume was estimated solely by sampling, using the criteria for an observed release to the Ground Water Migration Pathway (Ref. 1, Section 2.2 ; SeeHazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 15 Table 11 ). The City of Willow Park and the City of Hudson Oaks supply water to most homes within the area of the site, except for some of the homes in the area of
Russell Road . During the SI and ESI efforts

, all domestic and public supply wells located within a quarter mile of the site and the majority of wells within a half mile of the site (Figure 2) were sampled. In addition all public supply wells within one mile
of the s ite were sampled (Ref. 10, pp. 16

- 18; Ref 12, pp. 17

- 19) . The location of the plume is shown on Figure 2, and encompasses those well with documented observed
releases of TCE concentration.

**•** The level of effort to identify the original source(s) of the hazardous substances by an
SI conducted March 9

– 11, and an ESI conducted June 22

– 24, 2010 (Ref. 10, pp. 17,27,29&43; Ref. 11, pp. 4,5,9,10,18&19; Ref. 13, pp. 11&45; Ref. 1 4, pp. 3&9; Ref. 15, p. 2) is discussed in the Possible Sources Section on page 20 of this
document ation record

.

See Figure 2

, Groundwater Sample Location Map. Location of the source, with reference to a map of the site:

Other

- Ground Water Plume with No Identified Source. Source type for HRS evaluation purposes:

Gas release to air: The air migration pathway was not evaluated; therefore, gas containment
was not evaluated. Containment

Particulate release to air: The air migration pathway was not evaluated; therefore, particulate
containment was not evaluated.

Release to groun d water: The Containment Factor Value for the ground water migration pathway was evaluated for “All Sources” for evidence of hazardous substance migration from source area (i.e., source area includes source and any associated containment structures). The applicable containment factor value was determined based on existing analytical evidence of hazardous substances in ground water samples from private and public wells ( documented releases are listed and referenced in Table 1). Therefore, based on no
line r and evidence of a release, the highest Ground Water Migration Pathway Containment Factor Value of 10 was assigned to Source No. 1 as specified in Table 3

- 2 of the HRS (Ref. 1, Section 3.1.2.1).

Release to surface water overland/flood migration component : The surface water pathway was not scored; therefore, surface water overland/flood migration component containment
was not evaluated.Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 16 2.2.2 Hazardous Substances Associated With A Source

The ground water plume with no identified source

, Source 1

, contains measured levels of
trichloroethene , for which observed releases were established within the Paluxy formation of
the Trinity aquifer , the aquifer being evaluated for the Ground W ater Migration Pathway.
T richloroethene was d etected above the backg round level in samples collected by the TCEQ
in 20 10 , including both the SI and ESI, tasked to the TCEQ by the USEPA, which are given
in Table 1 below

. All field work was conducted as outlined in the work plan, including the Expanded Site Inspection Healt h and Safety Plan (HASP), and the TCEQ/EPA approved Quality Assurance Project Plan (QAPP) for TCEQ Preliminary Assessment/Site Inspection Program: Federal Grant Identification Number V

- 96665501

- 0 (Ref. 1 6; Ref. 17 ; Ref. 29; Ref.
41 ) . All deviations from the work plan and/or QAPP were noted in the field notebooks (Ref. 10; Ref. 13)

. The laboratories t hat test ed the samples for the Circle Court Ground Water
Plume were:

**•** US EPA Region 6 Laboratory, 10625 Fallstone Road, Houston, Texas 77099 (Ref. 18; Ref. 1 9; Table 7 )

**•** ChemTech Consulting Group, 284 Sheffield Street, Mountainside, New Jersey 07092 (Ref. 20; Table 7 )

**•** A4, The Woodlands, Texas

– 1544 Sawdust Road, Suite 505, The Woodlands, Texas
77380 (Ref. 21; Ref. 22 ; Ref. 23; Ref. 27; Table s 7 and 8 )

**•** Mitkem Corporation, Warwick, Rhode Island

– 175 Metro Center Boulevard, Warwick, RI 02886 ( Ref. 25; Ref. 26; Table 8 )

Tap w ater samples collected closest to the well s prior to treatment were analyzed by method
CLP SOM01.2, for organic drinking water analysis and method CLP ISM01.2, for ino rganic drinking water analysis (See Table 1 ; Table 7; and Table 8 )

. The analytical results
documented the organic compound t richloroeth ene greater than or equal to the background sample(s) quantitation limit, if not detected in background samples (see Table s 7 and 8 ).

Not all of the depths for the water wells are specified due to lack of information known by
the well owner s . A ccording to a Drinking Water Survey Report

, the wells with documented well depths are typically screened between 100 and 250 feet below ground surface, which draws from the Paluxy Formation of the Trinity Aquifer (Ref. 5 , p. 5 6 ). For the purpose of
this record

, only those wells installed in the Paluxy formation of the Trinity aquifer were included in the Ground Water Migration Pathway Score.Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 17 Table 1: Sample Collection for Source 1

– Other (Ground Water Plume with No Identified Source) Note: TCE was not detected in any of the background wells, during either the SI or ESI. Background
wells are listed in Tables 5 and 6
Well
ID* Sample
Location/Event Well Depth (feet) Date
Collected TCE
Detection
Level In μg/L Reference

GW

- 04 Non

- Drinking Water
Well at Parker Co. Airport Not Specified, but
from the Paluxy
Formation of the Trinity Aquifer (Ref. 5, p. 56) 3/11/10 5.4 Ref. 10, p. 37; Ref. 11, pp. 13

- 17; Ref. 16; Ref. 22, pp. 11,18 &26; Ref. 29, p. 19; Ref. 38, pp.
1

- 6
GW

- 25 3/11/10 5.4 Ref. 10, p. 37; Ref. 11, pp. 13

- 17; Ref. 16; Ref. 22, pp. 14,18 &35; Ref. 29, p. 18; Ref. 38, pp.
1

- 6
GW

- 05 PWS 117 Circle
Court Willow Park Municipal System’s
Well #20 240 (Ref. 4, p. 10) 3/9/10 6.5 Ref. 10, p. 17; Ref. 11, pp. 4 & 5; Ref. 16; Ref. 21, pp. 10,28& 39; Ref. 29, p. 18; Ref. 38, pp.
1

- 6
GW

- 10 Drinking water well
at 546 Russell Road 180

- 200 (Ref. 28, p. 7) 3/10/10 10 Ref. 10, p. 27; Ref. 11, p. 9; Ref. 16; Ref. 21, pp. 15,29&54; Ref. 29, p. 19; Ref. 38, pp. 1

- 6
GW

- 11 Drinking water well
at 550 Russell Road 280; Screened 100

- 280 (Ref. 28, p. 7) 3/10/10 2.5 Ref. 10, p. 29; Ref. 11, p. 10; Ref. 16; Ref. 21, pp. 16,32&57; Ref. 29, p. 19; Ref. 38, pp. 1

- 6
GW

- 33 6/22/10 3.8 Ref. 13, p. 7; Ref. 14, p. 1; Ref. 16; Ref. 25, pp. 11,31&33; Ref. 41, p. 15; Ref. 39, pp. 1

- 7
GW

- 12 Drinking water well
at 108 Circle Drive Not Specified, but from the Paluxy
Formation of the Trinity Aquifer (Ref. 5, p. 56) 3/11/10 1.3 Ref. 10, p. 43; Ref. 11, pp. 18 & 19; Ref. 16; Ref. 22, pp. 12,19&29; Ref. 29, p. 19; Ref. 38, pp. 1

- 6
GW

- 41 Drinking water well
at 405 Russell Road 200; screened 160

- 194 (Ref. 28, p. 7) 6/22/10 43 Ref. 13, p. 11; Ref. 14, p. 3; Ref. 16; Ref. 25, pp. 20,31&68; Ref. 41, p. 15; Ref. 39, pp. 1

- 7
GW

- 48 Drinking water Well
at 179 Annetta Road Not Specified, but from the Paluxy
Formation of the Trinity Aquifer (Ref. 5, p. 56) 6/24/10 2.7 Ref. 13, p. 45; Ref. 14, p. 9; Ref. 16; Ref. 26, pp. 8,12&16; Ref. 39, pp. 1

- 7; Ref. 41, p. 16.

Note: * Some sample locations have multiple Sample IDs. However, the multiple Sample IDs correspond to the same sample location. The multiple Sample ID numbers are due to use of different Sample IDs during different sampling events at those sampling location s.Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 18 2.2.3 Hazardous Substances Available to a Pathway

The containment factor value for Source 1 is 1 0 (see Containment in Section 2.2.1 of this
documentation record )

. T he following hazardous substances associated with the ground

water plume source can migrate via the ground water pathway:

Table 2: Hazardous Substance Available to a Pathway

Hazardous
Substances Air Pathway Ground
Water Surface Water Soil Exposure

Gas Particulate Overland/
Flood GW to
SW Resident Nearby

Trichloroethene NS NS Y NS NS NS NS

Notes and Qualifiers:
NS = Not Scored
Y = YesHazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 19 2.4 Waste Characteristics

2.4.2 Hazardous Waste Quantity

2.4.2.1 Source Hazardous Waste Quantity

2.4.2.1.1 Hazardous Constituent Quantity (Tier A)

– Not Evaluated (NE)

The information available is not sufficient to evaluate Tier A as required in Section 2.4.2.1.1 of the HRS, which is to determine total mass of the hazardous substance present in the waste

source

. The lack of manifests detailing waste quantities does not s upport the use of Tier A

. The mass of all the hazardous substances has not been determined a s a result, the evaluation of Hazardous Waste Quantity proceeds to the evaluation of Tier B, hazardous waste stream quantity (Ref. 1, Section 2.4.2.1.1).

2.4.2.1. 2 Hazardous Waste s tream Quantity (Tier B)

- NE

There is not sufficient information to evaluate Tier B which requires determining mass of the
hazardous wastestreams that are allocated to th e source as required in the HRS (Ref. 1, Section 2.4.2.1.2)

. Bec ause the original source of contamination is unknown, the hazardous wastestream quantity cannot be calculated and the evaluation of Hazardous Waste Quantity proceeds to the evaluation of Tier C, volume (Ref. 1, Section 2.4.2.1.2).

2.4.2.1.3 Volume (Tier C)

For the migration pathways, the source is assigned a value for volume using the appropriate Tier C equation from HRS Table 2

- 5 (Ref. 1, Section 2.4.2.1.3). The hazardous waste quantity for a plume site with no identified source can be determined by measuring the area within all observed release samples combined with the vertical extent of contamination to arrive at an estimate of the plume volume (Ref. 15 , p. 4).

However, t he lack of the vertical extent of contaminant delineation prohibits an exact volume concentration. The presence of contaminated ground water samples shows that the volume is greater than zero. Therefore, the volume of the ground water plume is assigned a volume hazardous waste quantity value greater than (>) 0 . The value of >0 reflects that the volume is known to be greater than 0, but the exact amount is unknown.

2.4.2.1.4 Area (Tier D)

Since the volume of greater than zero was assigned to the Tier C, the area (Tier D) is not to
be evaluated and instead, assigned a value of 0 (Ref. 1; Section 2.4.2.1.3).Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 20 2.4.2.1.5 Source Hazardous Waste Quantity Value

As described in the HRS, the highest value assigned to a source from among the four tiers of hazardous constituent quantity (Tier A), hazardous waste stream quantity (Tier B), volume (Tier C) or area (Tier D) was selected as the source hazardous waste quan tity value (Ref. 1, Section 2.4.2.1).

Table 3: Source Hazardous Waste Quantity Source No. 1 , Other

– Ground Water
Plume with No Identified Source

Tier Measure Migration Pathway (Ground Water)

Tier A, Constituent Quantity NE

Tier B, Wastestream Quantity NE

Tier C, Volume > 0

Tier D, Area 0

NE = Not Evaluated

Source No. 1, Other

– Ground Water Plume with No Identified Source, Hazardous Waste Quantity Value: > 0Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 21 SOURCE SUMMARY

The TCEQ conducted sampling activities at the Circle Court Ground Water Plume during
2010

. Thirty

- three wells were sampled by the TCEQ during 2010, sixteen wells were sampled during the March 2010 SI and seventeen wells were sampled during the June 2010
ESI (Ref. 9; Ref. 12 ). The source hazardous waste quantity and containment for the site is
summarized in the table below.

Table 4: Source Summary

Source
Number Source Hazardous Waste Quantity
Value Containment

Ground
Water Surface Water Soil Exposure Gas Air Particulate

1 > 0 10 NE NE NE NE

TOTAL > 0

NE = Not Evaluated

POSSIBLE SOURCES

The site is designated as a trichlor o ethene

- contaminated ground water plume originating
from an unknown source or sources. A limited number of potential sources of TCE are
located within a half mile of the site. The area of the site is rural residential with very little commercial activity in the area. Wells with no detection of TCE are located between each
commercial business and the site. TC E may have been used as a degreasing agent for metal parts. During the SI, soil sample locations were selected that appeared to be the most likely
locations to detect TCE

, from the most likely potential sources. The SI Work Plan included ten soil samples to be collected, but during the SI soil sampling event, the number of soil samples was reduced, since the only known likely potential sources were the Parker County Airport and a lawnmower repair shop. Since no other locations were suspected to use TCE, the number of soil samples collected was reduced from ten to six

. Soil samples were collected at the following locations:

1. The Parker County Airport is located near the most northwestern point of the documented TCE plume location (Figure 3, SO

- 04). The Parker County Airport’s

non

- drinking water well had a detection of TCE at 5.4 μg/L (Table 7 and Figure 2,
GW

- 04 and duplicate GW

- 25). Although there is no documented use of TCE at the Parker County Airport, its location and lack of many other business es in the area led
to its selectio n as a soil sample location (Ref. 9, pp. 33 and 34; see also Section 2.2.1
of this HRS documentation record). The slope of the terrain at the airport allowed for an excellent soil sample location. A low area created a natural funnel that would catch any runoff from coming from the airport’s hangers and control building area.

2. Ron’s Mower Shop, a seasonally ope n lawnmower repair shop is located near the most northwestern point of the TCE plume, between the Parker County Airport and Russell Road (Figure 3, SO

- 03). Although there is no documented use of TCE at the mower repair shop, considering the type of busine ss, its location, and lack of otherHazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 22 businesses in the area led to its selection as a soil sample location. A non

- drinking water well is located at Ron’s Mower Shop, which was sampled and no TCE was documented in the well (Table 7, and Figure 2, GW

- 36 ; Ref . 39, pp. 1

- 7 ). The soil sample for the lawnmower repair shop was collected close to and directly in front of the maintenance building and down slope to catch any releases from that business (Ref 9, p. 53; Ref 11, p. 21)

.

3. N o additional potential source s were discovered during the SI ; the ESI focused on identifying and protect ing any population exposed to drinking water wells supplying
TCE

- contaminated water . In addition the comprehensive sampling of wells within an
1⁄2 mile radius was used to further iden tify any groundwater concentrations that could be indicative of other source areas. The sampling of these wells did not indicate any additional potential sources. Within the area of the TCE plume , no soil samples were collected during the ESI (Ref. 10, pp. 17,27,29&43; Ref. 11, pp. 4,5,9,10,18&19; Ref. 13, pp. 11&45; Ref. 14, pp. 3&9).

4. During the ESI sampling event, the well owner of GW

- 34 expressed concern about an active natural gas well located approximately 1,000 feet north of his well (Ref. 13, p. 9) . The filter from well GW

- 34 appeared black and oily (Ref. 14, p. 2, Photographs 3&4). TCE was not detected in the GW

- 34 well (Ref. 25, pp. 12&44). TCE was not
detected in the closest well to the natural gas well

.

### ! .

! .

! .

! . ! . ! . ! . ! . ! .

! .

! . ! . SO-03 SO-01 SO-02

SO-04 SO-05/SO-06 I 20 Mikus

Interstate 20

Russell

Rob Interstate 20 Service

WEA Oak Hill Red BudParker Oaks Mallory

Southview Diamond Oaks Arroyo

Valley

Circle Deer Pond Dorris Fort Worth

Big Creek Oak Hollow

Elm Tree Austen Live Oak Bluebonnet

Addison Park

Elm Green Oaks Primrose

Crown

Airport Pecan Park Ranch Oak Yucca Valley Trail Winfield

McClure Holly Oak

Brookview Oak Hollow Fort Worth

Interstate 20 Service Live Oak 

## Figure 3: Soil Sample Location Map 

# μ

Circle Court Groundwater Plume Parker County, Texas TXN000606965

Legend



### ! . Soil Sample Location


### ! . Level 1 Concentration Wells

Parker County

This map was generated by the Remediation Division of the Texas Commission on Environmental Quality. It is intended for illustrative or informational purposes only, and is not suitable for legal, engineering, or survey purposes. This map does not represent an 0 250 500 750 1,000 1,250 1,500 1,750 2,000 2,250 2,500 2,750 3,000 3,250 3,500 3,750 4,000 4,250 4,500 4,750 5,000 on-the-ground survey conducted by or under the supervision of a registered professional land surveyor. In cases where property boundaries are shown, it only represents their approximate relative Feet location. No claims are made to the accuracy or completeness of the data or to its suitability for a particular use. For more information concerning this map, contact the Remediation Division at 800-633-9363. The base data set is UTM Zone 14, 0.5 Meter Resolution, Natural Color, NAD 1983Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 24 3.0 GROUND WATER MIGRATION PATHWAY

3. 0. 1 General Considerations

General Regional Geology

The site is located in the Grand Prairie natural subregion of Texas (Ref. 30, p. 1). The Grand Prairie is underlain by alternating limestones and marls of the Cretaceous age Fredericksburg Group. The intervening marls form low escarpments that connect su ccessive uplands and produce a “cuesta” topography that slopes gently eastward (Ref. 31, p. 11). The Fredericksburg Group consists predominantly of limestone, shale, clay, and marl, and yields only small amounts of water to localized areas (Ref. 31, p. 15 ). The City of Willow Park’s PWS well located at 117 Circle Court in Willow Park (GW

- 05 on Figure 2) is located on the Walnut Clay Formation, which consists of clay and limestone and has a thickness of approximately 30 feet (Ref. 32, p. 6 ). However, the surface lithology varies considerably within small distances due to the interfingering of several different formations, including the Goodland Limestone and Walnut Clay of the Fredericksburg Group; the Kiamichi and Duck Creek Limestone of the Washita Group ; the Quaternary Alluvium; and the Paluxy Formation of the Trinity Group (Ref. 34, p. 9). The outcrop of the more permeable sand

- dominated and

water

- bearing Paluxy Formation is within 0.10 mile both north and east of the City of Willow Park Well #20, and within 0.25 mile of the well in the southwest direction (Ref. 34, p. 9; Figure 4A).

The Fredericksburg Group is underlain by the Cretaceous age Trinity Group formations, from youngest to oldest, the Paluxy, Glen Rose, and Twin Mountains. Each of the forma tions
is water

- bearing and together compose the Trinity aquifer, recognized as a major aquifer by the Texas Water Development Board (TWDB) (Ref. 34, p. 9). The TWDB defines a major aquifer as one that supplies large quantities of water over large areas of the state (Ref. 44, p.
4 ).

The main source of recharge to the Trinity is precipitation on the outcrops of the formations within the aquifer. There are no separations by aquitards or confining layers between the formations, and using the Texas Water Dev elopment Board’s ground water availability model (“GAM”) for the Northern Trinity aquifer, hydrologic interaction was calculated between the stratigraphic units. The estimated flow between the Paluxy and the Glen Rose was calculated to be 2,678 acre

- feet per year, and the Glen Rose into the Upper Travis Peak, the equivalent to Twin Mountains in the model, was calculated to be 3,937 acre

- feet per year (Ref. 34, p. 5, pp. 12

- 13, p. 22, p. 29). There are no known aquifer discontinuities within the
four

- mile TDL. The nearest zone of faults or fractures is approximately 60 miles east and southeast of the site (Figure 4B). The direction of ground water flow in the three formations is generally towards the east and southeast (Ref.34, p. 8).

Water use in the area supplied by the Trinity aquifer has increased in the past fewHazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 25 decades due to increasing population and municipal use. In addition, recent usage has increased due to the development of natural gas wells in the Barnett Shale. The water is necessary to hy draulically fracture the dense formation around the gas wells, using about 1.2 to 3.5 million gallons per well during the process. It is estimated that approximately 60 percent of this water will continue to come from either the Trinity or Woodbine aquife rs (Ref. 45, p. 9).

T he northern Trinity aquifer is a sole

- source water supply for many rural areas and municipal supplies (Ref. 35, p. 26 ). Ground water provided 52.1 percent (11,231 acre

- feet of a total 21,527 acre

- feet) of total water used in Pa rker County in 2006 (Ref.35, p. 33 ).

## ! ! 

## 2 Site Center I - 20

FM 5 FM 730

US HWY 180

FM 1187

FM 51 ST HWY 171 FM 3325

FM 2552 Kpa Kwa

Kgl

Qal Kki Wa

Kdc

Parker County

This map was generated by the Remediation Division of the Texas Commission on Environmental Quality. It is intended for illustrative or informational purposes only, and is not suitable for legal, engineering, or survey purposes. This map does not represent an on-the-ground survey conducted by or under the supervision of a registered professional land surveyor. In cases where property boundaries are shown, it only represents their approximate relative location. No claims are made to the accuracy or completeness of the data or to its suitability for a particular use. For more information concerning this map, contact the Remediation Division at 800-633-9363. 

# Figure 4A: Surface Geology Map

Circle Court Groundwater Plume Parker County, Texas TXN000606965

The base data used for this map is from the Geologic Database of Texas published by theTexas Water Development Board and the U.S. Geological Survey. The digital data can be accessed at the URL http://data.tnris.org/datadownload/download.jsp Coordinate system is UTM Zone 15, Northern Hemisphere (NAD 83). 0 1 2 3 4 0.5 Miles Legend

Paluxy

Walnut Clay Duck Creek Limestone

Glen Rose Limestone

Kiamichi Alluvium 

# μ

Parker County

### ^ _ WOODBINE AQUIFER (subcrop) NACATOCH AQUIFER (subcrop) WOODBINE AQUIFER NACATOCH AQUIFER

CARRIZO AQUIFER TRINITY AQUIFER TRINITY AQUIFER (subcrop)

Hill County Ellis County

Navarro County Dallas County Parker County Tarrant County

Bosque County Kaufman County

Johnson County Collin County Wise County

Hunt County Denton County

Hood County

Freestone County Henderson County

Erath County Somervell County Jack CountyVan Zandt County Rockwall County

Hamilton County

McLennan County Limestone County Anderson County 

# μ

This map was generated by the Remediation Division of the Texas Commission on Environmental Quality. It is intended for illustrative or informational purposes only, and is not suitable for legal, engineering, or survey purposes. This map does not represent an on-the-ground survey conducted by or under the supervision of a registered professional land surveyor. In cases where property boundaries are shown, it only represents their approximate relative location. No claims are made to the accuracy or completeness of the data or to its suitability for a particular use. For more information concerning this map, contact the Remediation Division at 800-633-9363. The base data used for the structural and geologic data for this map is from the Geologic Database of Texas published by theTexas Water Development Board and the U.S. Geological Survey. The digital data can be accessed at the URL http://data.tnris.org/datadownload/download.jsp. Coordinate system is UTM Zone 15, Northern Hemisphere (NAD 83). 

# Circle Court Groundwater Plume Parker County, Texas TXN000606965

PARKER COUNTY Legend

Minor Aquifers

Nacatoch (outcrop)

Nacatoch (subcrop)

Woodbine (outcrop)

Woodbine (subcrop) Structural Features

! ! ! Concealed Normal

Inferred Normal

S Normal

I Overturned Anticline

P Overturned Syncline F Anticline

+ Thrust

& Transverse (From-To)
$ Transverse (To-From)

Unspecified F Syncline Trinity (outcrop)
Trinity (subcrop) Major Aquifers

Carrizo (outcrop)

Location Features

^ Approximate Site Location

4 Mile Radius

Cities 

# Figure 4B: Regional Geology and Aquifers

0 10 20 30 40 50 5

MilesHazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 28 The geologic strata beneath the site, from youngest to oldest, are:

Stratum 1:

The Walnut Clay Formation of the Fredericksburg Group consists of clay and limestone, about equally abundant, with a thickness of approximately 30 feet (Ref. 32. p. 6 ). Walnut Clay Formation

- Fredericksburg Group

Stratum 2:

The Paluxy Formation is the uppermost of the three water

- bearing formations that comprise the Trinity aquifer. The Paluxy is composed predominantly of fine

- to coarse

- grained, friable, homogeneous, white quartz sand, interbedded with sandy, silty, calcare ous, or waxy clay and shale. The upper Paluxy is fine

- grained sand with variable amounts of shale and clay. The lower part consists of coarse

- grained sand. The sands are usually well

- sorted, poorly cemented, and crossbedded (Ref. 31, p 19). Paluxy Formation

- Trinity Group Aquifer

The Paluxy e ither underlies one of the Fredericksburg Group formations or outcrops in the area of the site (Figure 4A). The primary source of recharge to the Paluxy is precipitation on the outcrop

. The average annual precipitation on the outcrop is about 31 inches, b ut only a small fraction of the amount is available as effective recharge due to runoff and evapotranspiration. Secondary sources include recharge from streams flowing across the outcrop, and surface water seepage from lakes. Water in the outcrop area is under water

- table conditions, and water levels remain fairly constant with only normal seasonal fluctuations. In subcrop areas, water is under artesian conditions and is confined under hydrostatic pressure from overlying formations. The average rate of movement of water in the Paluxy amounts to less than 2 feet per year in an easterly direction except in areas of heavy pumpage, where cones of depression have occurred and movement is toward the center of the pumped wells. The hydraulic gradient is approxi mately 27 feet per mile. The direction of ground water flow is toward the east and southeast. Discharge from the Paluxy occurs naturally through springs and evapotranspiration and artificially through pumpage from water wells. The Paluxy is capable of yi elding small to moderate amounts of water (Ref. 31, pp. 44

, 46 ). The City of Willow Park’s PWS well located at 117 Circle Court in Willow Park (GW

05 on Figure 2) is screened within the Paluxy Formation of the Trinity aquifer (Ref. 5, p. 56).

Stratum 3

The Glen Rose Formation underlies the Paluxy and consists predominantly of marine carbonates, mainly limestone, with some shale, sandy shale, and anhydrite. The formation yields small quantities of water to lo calized areas (Ref. 31, p. 1 6 ; Ref. 33, p. 20). : Glen Rose Formation

- Trinity Group Aquifer

Stratum 4

The Twin Mountains Formation underlies the Glen Rose and consists mainly of medium

- to

coarse

- grained sands, red and gray silty clays, and silic eous conglomerates of chert, quartzite, and quartz pebbles. The sand strata are more thickly bedded in the lower part of the formation than the upper and middle. The majority of wells in this formation are completed
in the lower massive sand. The direct ion of ground water flow in the Twin Mountains is toward the east and southeast. The Twin Mountains is the most prolific of the Trinity aquifer : Twin Mountains Formation

- Trinity Group AquiferHazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 29 formations; however, the water quality is generally not as good as that from the Paluxy Formation (Ref. 31, p. 18

- 19; Ref. 33, p. 20).

The Twin Mountains Formation overlies Paleozoic rocks in the study region and is the lower member of the Trinity Group. The formation was originally named the Travis Peak Formation throughout its extent in Texas, but the north

- cen tral portion was subsequently re

named the Twin Mountains Formation because of a lateral facies change (Ref. 31, p. 18; Ref. 33, p. 20). The Twin Mountains consists mainly of medium

- to coarse

- grained sands, silty clays, and conglomerates, while the Travi s Peak contains calcareous sands and silts, conglomerates, and limestones (Ref. 33, p. 20). The outcrop of the Twin Mountains covers approximately 370 square miles and lies within Hood, Parker and Wise counties. Precipitation on the outcrop is the primary source of ground water in the Twin Mountains (Ref. 31, p. 41). Only ground water wells screened in the Paluxy formation are considered for the purposes of this HRS.

3.1 Likelihood of Release

3.1.1 Observed Release

An observed release was documented to the ground water pathway for the site by chemical analysis. To establish an observed release by chemical analysis, it requires analytical evidence of a hazardous substance in the media significantly above the background level. If the background conce ntration is not detected, or is less than the detection limit, an observed release is established when the sample measurement equals or exceeds the EPA contract

required quantitation limit (CRQL) when the sample analysis was performed under the EPA
Contrac t Laboratory Program (Ref. 1, Section 2.3, Table 2

- 3).

Background Concentration

Five background samples were collected in excess of a half mile outside of the plume area

, except for one background well. Background well GW

- 03 was collected west of the plume nearly one half mile away and upgradient and out of the influence of the site.

The background wells were selected based on the range of their well depths being in t he same aquifer and of similar depths as the drinking water wells at the s ite. All of the depths of the background wells are known and range from 176’ to 260’ ( Ref. 10, pp.3, 21, 23; Ref. 11, pp.1,7; Ref. 13, p p. 2 3, 25 ; Ref 14 p. 5 ). Not all of the depths for the domestic water wells are specified due to lack of documented information and well owners ’ knowledge

. There is relatively little topographic change in the area of the site and the well depth measurements
are sufficient to show the depths relative to each other (Ref 3, pp. 1

- 2)

. According to a Drinking Water Survey Report, the wells with TCE detections and with documented well depths had depths similar to the background wells, ranging from 180’ to 2 8 0’ (Ref. 28, pp. 7

- 8). For the purpose of this record, only those wells installed in the Paluxy formation of the Trinity aquifer were included in the Ground Water Migration Pathway Score. Thus, the background and release samples are likely from the same aquifer and have the same sample similarity. All samples were collected according to the EPA

- approved state QualityHazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 30 Assurance Project Plan (QAPP) and sample locations were approved by the E PA (Ref. 16 ; Ref. 29, pp. 17

- 19; Ref. 41, pp. 14

- 16 )

. Table s 1 and 11 provide well depths, references, and
TCE detection levels for the wells with observed releases. Table 5 provides well depths and
references for each of the background ground water samp les collected. Table 6 provides a summary of the designated background levels for the hazardous substances of concern for
this site.Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 31 Table 5: Background Ground Water Samples Collected
Sample

ID* Sample Location Well Depth (feet) Date
Collected Reference s

GW

- 01 Drinking water well at Highland WSC Well #4 ; 3600 Oak Park 250 (Ref. 28

, p. 8) 3/09/2010 Ref. 10 , p. 3 ; Ref. 11, p. 1
GW

- 31 6/23/2010 Ref. 1 3 , p. 25 ; Ref. 14, p. 5
GW

- 02 Drinking water well at Hudson Oaks Well #6 ; 3250 I

- 20 East 260 (Ref. 28

, p. 8) 3/10/2010 Ref. 10 , p. 21 ; Ref. 11, p. 7
GW

- 03 Drinking water well at Hudson Oaks Well #8,
220 Live Oak 176 (Ref. 28

, p. 8) 3/10/2010 Ref. 10 , p. 23 ; Ref. 11, p. 7
GW

- 32 Drinking water well at Willow Park PWS

– Willow Springs Well at Quail Crest Road. 260 (Ref. 1 3

, p. 23) 6/23/2010 Ref. 1 3 , p. 23 ; Ref. 14, p. 5

Notes: * Background sample locations have multiple Sample IDs. The multiple Sample IDs correspond to the same sample location. The multiple Sample ID numbers were due to use of different Sample IDs during different sampling events at these sampling locations.

Table 6: Summary of Highest Constituents Detected in the Background Ground Water
Wells

Sample

ID Organic
Constituent Highest
Concentration

[ RL ] μg/L* References

GW

- 01 Trichloroethene ND [0.5] Ref. 10, p. 3; Ref. 11, p. 1; Ref. 16; Ref. 21, pp. 9 ,27 & 36 ; Ref. 29; p. 17; Ref. 38, pp. 1

- 6

GW

- 02 Trichloroethene ND [0.5] Ref. 10, p. 21; Ref. 11, p. 7; Ref. 16; Ref. 22, pp. 9 ,17 & 20 ; Ref. 29; p. 17; Ref. 38, pp. 1

- 6

GW

- 03 Trichloroethene ND [0.5] Ref. 10, p. 23; Ref. 11, p. 7; Ref. 16; Ref. 22, pp.
10 ,17 & 23 ; Ref. 29; p. 17; Ref. 38, pp. 1

- 6

GW

- 31 Trichloroethene ND [0.5] Ref. 13, p. 25; Ref. 14, p. 5; Ref. 16; Ref. 25, pp. 9 ,32 &3 5 ; Ref. 41; p. 14; Ref. 39, pp. 1

- 7

GW

- 32 Trichloroethene ND [0.5] Ref. 13, p. 23; Ref. 14, p. 5; Ref. 16; Ref. 25, pp.
10 ,32 &3 8 ; Ref. 41; p. 14; Ref. 39, pp. 1

- 7

Notes:
ND = Not Detected [ R L] = Reporting Limit
* For all of the analyses the reporting limit in t he references cited is the adjusted for sample volume, dry weight, and dilution factors . The RLs are equivalent to adjusted CRQLs and consistent with the HRS defined detection / quantitation limits. (Ref. 36 ).

Given t hat all of the background samples have no detected trichloroethene , the background level is ND [ 0.5 μg/L]

.

Contaminated Samples

The samples in Table s 7 and 8 meet the observed release criteria and are presented below indicating the hazardous substance with concentrations and RL s. These samples were qualified as “releases” based on the criteria in HRS Table 2

- 3 (Ref. 1, Section 2.3).Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 32 Table 7: Trichloroethene Contaminated Ground W ater Pathway Aquifer Samples
M eeting Observed Release Criteria ( March 2010 SI Results)

Sample ID Well Type TCE Conc. ( μ g/L) RL - (μg/L) * Reference s

GW

- 04 & ** Duplicate GW

- 25 Non

- Drinking
Water 5.4 0. 5 Ref. 10, p. 37; Ref. 11, pp. 13

– 17 ; Ref. 16; Ref. 22, pp. 14 ,18 ,26 & 35 ;

Ref. 29

, p. 19 ; Ref. 38, pp. 1

- 6

GW

- 05 PWS Drinking
Water 6.5 0.5 Ref. 10, p. 17; Ref. 11, pp. 4&5 ; Ref. 16; Ref. 21, pp. 10 ,28 & 39 ; Ref. 29

, p. 18 ; Ref. 38, pp. 1

- 6

GW

- 10 Private Drinking
Water 10.0 0.5 Ref. 10, p. 27; Ref. 11, p. 9 ; Ref. 16; Ref. 21, pp. 15 ,31 & 54 ; Ref. 29

, p. 19 ; Ref. 38, pp. 1

- 6

GW

- 11 Private Drinking
Water 2.5 0.5 Ref. 10, p. 29; Ref. 11, p. 10 ; Ref. 16; Ref. 21, pp. 16 ,32 & 57 ; Ref. 29

, p. 19 ; Ref. 38, pp. 1

- 6

GW

- 12 Private Drinking
Water 1.3 0.5 Ref. 10, p. 43; Ref. 11, pp. 18&19 ; Ref. 16; Ref. 22, pp. 12 ,19 & 2 9; Ref.
29

, p. 19 ; Ref. 38, pp. 1

- 6

Notes: [ RL ] = Reporting Limit. * For all of the analyses the reporting limit in the references cited is based on the method detection limit (Ref. 36 ). **Sample locations have multiple Sample IDs. The multiple Sample IDs correspond to the same sample location. The multiple Sample ID numbers were due to use of different Sample IDs during different sampling events at these sampling locations.

Table 8: Trichloroethene Contaminated Ground Water Pathway Aquifer Samples Meeting Observed Release Criteria (June 2010 ESI Results)

Sample ID Well Type TCE Conc. (μg/L) RL - (μg/L)* Reference s

GW

- 33 Private Drinking Water 3.8 0.5 Ref. 13, p. 7; Ref. 14, p. 1 ; Ref. 16; Ref. 25, pp.
11 ,31 & 41 ; Ref. 39, pp. 1

- 7

GW

- 41 Private Drinking Water 43.0 0.5 Ref. 13, p. 11; Ref. 14, p. 3 ; Ref. 16; Ref. 25, pp.
20 ,31 & 68 ; Ref. 39, pp. 1

- 7

GW

- 4 8 Private Drinking Water 2.7 0.5 Ref. 13, p. 45; Ref. 14, p. 9 ; Ref. 16; Ref. 26, pp. 8 ,12 &1 6 ; Ref. 39, pp. 1

- 7

Notes: [ RL ] = Reporting Limit

. * For all of the analyses the reporting limit in the references cited is based on the method detection limit (Ref. 36 ).Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 33 Attribution

The site is designated as a contaminated ground water plume originating from unknown source(s) where trichloroethene may have been released and percolated through the ground to the aquifer. When the source itself consists of a ground water plume with no identified source, no separat e attribution is required (Ref.1, Sec. 3.1.1). The site is located in a rural and residential area, with very little commercial activity. During the SI

, conducted in March 2010, all potential surface sources were sampled (Ref. 10, pp. 47, 49, 51, 53, and 55; Ref. 11, pp. 19

- 21; Ref. 29, pp. 15&23) and no TCE was detected in any of the soil samples (Ref. 9,

pp. 19

- 20 ). The SI was allotted ten soil samples to search for a surface source of TCE contamination, due to the lack of commercial activity in the ar ea of the site, only six soil samples were collected and no other likely soil sampling locations remained for the ESI. The
June . N o additional potential sources were discovered during the SI ; the ESI focused on identifying and protect ing any population exposed to drinking water wells supplying TCE

contaminated water . In addition the comprehensive sampling of wells within an 1⁄2 mile radius was used to further identify any groundwater concentrations that could be indicative of
other source a reas. The sampling of these wells did not indicate any additional potential
sources. Within area of the TCE plume, no soil samples were collected during the ESI. (Ref. 10, pp. 17,27,29&43; Ref. 11, pp. 4,5,9,10,18&19; Ref. 13, pp. 11&45; Ref. 14, pp. 3&9). The ESI potential source location GW

- 41 was documented to have the highest level of TCE at 43 μg/L (Ref. 13, p. 11; Ref. 14, p. 3; Ref. 16; Ref. 25, pp. 20, 31&68; Ref. 39, pp. 1

- 7) and is also located approximately at the center of the plume, see Figur e 2.

Hazardous Substances Released

The following hazardous substance was released: Trichloroethene As specified in the HRS (Ref. 1, Section 3.1.1), an observed release factor value of 550 was assigned to the Paluxy formation of the Trinity aquifer since an observed release by chemical analysis was established in the Paluxy formation of the Trinity aquifer (See Table 11).

Observed Release Factor Value: 550Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 34 3 .1.2 Potential to Release

As specified in the HRS, since an observed release was established for the Paluxy formation
of the Trinity a quifer, the potential to release was not evaluated (Ref. 1, Section 3.1.1).

3.1.3 Likelihood of Release Factor Category Value

As stated in the H RS, if an observed release is established for an aquifer, assign the observed release factor value of 550 as the likelihood of release factor category value for the aquifer (Ref. 1, Section 3.1.3). Since an observed release has been established for the aq uifer, the Observed Release Factor Value of 550 is assigned as the likelihood of release factor category
value.

3.2 Waste Characteristics

3.2.1 Toxicity/Mobility

The hazardous substance with the highest toxicity factor value available to the ground water migration pathway is trichloroethene , which has a toxicity/mobility value of 1,000

. Therefore, the following toxicity, mobility

, and combined toxicity/mobility factor value has been assigned to the substance s associated with Source No. 1, or present in the observed release, which has a containment value greater than 0.

Table 9 : Toxicity/Mobility Factor Values

Hazardous
Substance Toxicity
Factor
Value Mobility
Factor
Value Toxicity / Mobility

Value Reference s

Trichloroethene 1,000 1 1,000 Ref. 1, Sections 2.4.1.2, 3.2.1; Ref. 2 , p. 6

Documentation for Toxicity/Mobility Values

The Mobility Factor Value for all hazardous substances that meet the criteria for an observed release by chemical analysis to one or more aquifers underlying the source(s) at the S ite, regardless of the aquifer being evaluated, is assigned a mobility facto r value of 1 (Ref. 1, Section 3.2.1.2).

Therefore, t he hazardous substance with the highest toxicity/mobility factor value available to the ground water migration pathway is trichloroethene with a toxicity/mobility factor value
of 1,000

.

Toxicity/Mobility Factor Value: 1,000Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 35 3.2.2 Hazardous Waste Quantity

The hazardous constituent quantity data is not adequately determined for one or more sources for the site. The targets for the Ground Water Migration Pathway are subject to Level I
concentrations (see Tables 7 and 8). According to Section 2.4.2.2 of the HRS, a pathway hazardous waste quantity factor value of 100 was assigned because the hazardous constituent quantity data is not adequately determined for one or more sources, and tar gets for the
Ground W ater Migration Pathway are subject to actual contamination (Ref. 1, Section 2.4.2.2).

Table 1 0 : Source Hazardous Waste Quantity Values

Source Number Source Hazardous Waste Quantity
Value Hazardous Constituent Quantity Data Complete?

1 > 0 N o Total > 0

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 Factor Value of 1 ,000, resulting in a product of 100,000 (1.0E+0 5 ). Based on this product, a Waste Characteristics Factor Value
of 18 was assigned from Table 2

- 7 of the HRS (Ref. 1, Section 2.4.3.1).

Hazardous Waste Quantity Factor Value: 100

Waste Characteristics Factor Value: 18Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 36 3.3 Ground W ater Pathway Targets

The primary aquifer being evaluated for the ground water pathway targets is the Paluxy
formation of the Trinity a quifer . The ground water pathway targets for this aquifer have been impacted with trichloroethene above a human health

- based cancer risk health

- based
benchmark . The number of target wells subject to Level I concentration of trichloroethene

, which is the concentration above a cancer risk health

- based benchmark

, is given in Table 1 1

. The population served is also given in T able 1 1 . The average population per household of
3.01 , which was based on the Parker County 2010 US Census Bureau information (Ref. 3 7

, p. 1)

, has been applied where the population size was not available from the water well

survey.

Table 11: Drinking Water Wells with Level I Concentration of Trichloroethene

Well ID TCE
Conc. μg/L Benchmarks/Screening
Concentrations ( Ref. 2, p. 6 , Ref. 24, pp. 4

- 6 & 12 ) Well Depth (feet)

Population
Served Reference MCL /
MCLG

μg/L (mg/L) Cancer
Risk Screen.
Conc. μg/L (mg/L) Ref.
Dose Screen.
Conc. μg/L (mg/L)

GW

- 05 6.5 5.0 μg/L

(5.0E

- 3) 0.21 μg/L

(2.1E

- 4) NA 180 272.48 Ref. 10, p. 17; Ref. 11, pp. 4&5; Ref. 16; Ref. 21, pp. 10 ,28 & 39 ; Ref. 28, p. 7; Ref. 29; p. 17; Ref. 38, pp. 1

- 6; Ref. 40, p. 1

GW

- 10 10.0 180

- 200 3.01 Ref. 10, p. 27; Ref. 11, p. 9; Ref. 16; Ref. 21, pp. 15 ,31 & 54 ; Ref, 28, p. 7; Ref. 29; p. 18; Ref. 38, pp. 1

- 6; Ref. 37, p. 1

GW

11*
GW

- 33 2.5

100

- 280 3.01 Ref. 10, p. 29; Ref. 11, p. 10; Ref. 13, p. 7; Ref. 14, p. 1; Ref. 16; Ref. 21, pp. 16 ,32 & 57 ; Ref. 25, pp. 12 ,31 & 41 ; Ref. 28, p. 7; Ref. 29; p. 18; Ref. 38, pp. 1

- 6; Ref. 39, pp. 1

- 7; Ref. 37, p. 1 3.8

GW

- 12 1.3 Depth Not Specified,

within Paluxy
Formation 3.01 Ref. 10, p. 43; Ref. 11, pp. 18&19; Ref. 16; Ref. 22, pp.
13 ,19 & 2 9; Ref. 29; p. 18; Ref. 38, pp. 1

- 6; Ref. 37, p. 1

GW

- 41 43.0 200 3.01 Ref. 13, p. 11; Ref. 14, p. 3; Ref. 16; Ref. 25, pp. 21 ,31 & 68 ; Ref. 28, p. 7; Ref. 39, pp. 1

- 7; Ref. 37, p. 1

GW

- 48 2.7 Depth Not Specified,

within Paluxy
Formation 3.01 Ref. 13, p. 45; Ref. 14, p. 9; Ref. 16; Ref. 26, pp. 9 ,12 & 16 ; Ref. 39, pp. 1

- 7; Ref. 37, p. 1

Total Population

Served 287.5 3

* GW

- 11 and GW

- 33 are samples collected on different dates, from the same well.

NA= Not available

.Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 37 3.3.1 Nearest Well

According to Section 3.3.1 of the HRS, if one or more drinking water wells are subject to Level I concentrations, a Nearest Well Factor value of 50 is assigned.

Level of Contamination (I, II, or potential): Level I

Location of Well: Level I concentrations have been documented at s ix drinking water wells within the ground water p lume. Well locations are identified in Table 1. The well located at 405 Russell Road, GW

- 41, was selected for calculation of the Nearest Well Factor Value, see Table 1 and Figure 2.

The ESI well location GW

- 41 was documented with 43 μg/L of trichloroe thene, which exceeds the MCL value of 5 μg/L (Ref. 13, p. 11; Ref. 14, p. 3; Ref. 16; Ref. 25, pp. 20

, 31 & 68 ; Ref. 39, pp. 1

- 7) . For a well with Level I concentrations, a Nearest Well Factor Value of 50 is assigned (Ref. 1, Section 3.3.1).

Nearest Well Factor Value: 50Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 38 3.3.2 Population

3.3.2.1 Level of Contamination

3.3.2.2 Level I Concentration s

The concentrations of hazardous substance shown in Table 1 1 include detections in drinking water wells that meet or exceed their corresponding benchmark concentrations; thus, these wells are associated with Level I concentrations (Ref. 1, Section 3.3.2.1

- 3.3.2.2).

One public supply and f ive private wells within a one

- mile radius of the S ite contained Level
I concentrations of hazardous substances (see Table 1 1 ). All the wells draw water from the Paluxy formation of the Trinity aquifer (Ref. 28, pp. 5

- 8). P ublic water supply is not
available to the owners of the private wells subject to Level I concentrations of hazardous
substances

.

As specified in the HRS (Ref. 1, Section 3.3.2.2), the number of people served by drinking water from points of withdrawal subject to Level I concentrations were summ ed. The City of
Willow Park has 19 wells serving 1

, 720 connections. No one well serves more than 40%

, (Ref. 40, p. 1; and Ref. 42, p. 1). Using the average population per household of 3.01 (Ref.
37 , p. 1), the total population counted from Level I wells is 272.48 from GW

- 05 and 15.05 from five private drinking water wells for a combined total of 287

. 5 3

. The total of 287.53 was multiplied by 10, for a product of 2,875.3 (Ref. 1, Section 3.3.2.2).

C alculations of Population Served by Level I wells: One public supply well (GW

- 05) : System serves 1720 (Ref. 40, p. 1)
= 1720 Nineteen wells contribute to equally (Ref. 40, p. 1) = Result = 90.52 ÷ 19

Multiplied by the 2010 average population (Ref. 37, p. 1) = Number of people served by GW

- 05 Result= 272.48 x3.01

Five Private drinking water wells: Multiplied by the 2010 average population (Ref. 37, p. 1) = 3.01 Five Wells (GW

- 10, GW

- 11, GW

- 12, GW

- 41, & GW

- 48) = Result = 15 .05 x5

Population Served by Level I wells 272.48 + 15 .05 = 287. 53 Level I Concentration Factor Value 287.53 x 10 (Ref. 1, Section 3.3.2.2) = 2

, 875 .3

Population Served by Level I Well: 287.53 Level I Concentration Factor Value: 2,875.3Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 39 3.3.2.3 Level II Concentration s

No Level II concentrations of TCE were documented. All concentrations of TCE meeting
the criteria for an observed release were at Level I Concentrations.

The cancer risk health

- based benchmark for TCE cancer risk is 0.21 μg/L ( Ref. 2, p. 6 , Ref. 24, pp. 4

- 6 & 12 ). Since TCE was not detected in any of the background samples and the laboratory’s TCE CRQL value of (0.5 μg/L) was greater tha n TCE’s cancer risk benchmark (0.21 μg/L)

, any detections of TCE met both the criteria of an observed release as well as a Level I concentration (Ref. 1

, Section 2.5.2 ).

Level II Concentration Factor Value: 0 Population Served by Level II Well: 0Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 40 3.3.2.4 Potential Contamination

The potential contamination factor was evaluated and scored. The ground water wells were
identified from the well database in the TCEQ GIS servers (Ref. 5 ). The wells were
researched within radii of 0 to 0.25, 0 .25 to 0.5, 0.5 to1, 1 to 2, 2 to 3, and 3 to 4

- miles of the
site (see Figure 4 A of this HRS documentation record ) . Using the average population per
household of 3.01 (Ref. 37 , p. 1 ), the potential targets (Table 1 2 ) were calculated based on
the number of we lls located within each distance category and the weighted population assigned from Table 3

- 12 of the HRS , using the “Other Than Karst” category

. Wells within the radii having Level I contamination are not discussed in this section and there are no Level II contamination wells, (See Section 3.3.2.3. of this HRS documentation record )

. Wells drawing from aquifers other than the Paluxy formation of the Trinity aquifer are not included
in this section. P WS systems are included in this potential contamination section, but not private domestic drinking water wells , since they lack documentation and add no additional
value

. Texas State well identification numbers, well depths, and distances from the site were obtained from the Texas Water Development Board’s Water Information Integration and Dissemination Groundwater Database interactive viewer, http://wiid.twdb.state.tx.us (Ref. 5)

. Information for the public water system wells were verified through contact with the respective water system ( Ref. 42; Ref. 43; Ref. 4 6 ; Ref. 4 7 )

.

0 to 0.25

- mile
All drinking water wells located in the 0 to 0.25

- mile range were sampled and analyzed for
TCE. Other than the PWS well subject to Level I contamination, no other PWS wells are located within this range.

0.25 to 0.5

- mile
In the 0.25 to 0.5

- mile range from the site , the following PWS wells are located :

State Well # D epth PWS P e op le Served
3211821 260 ’ Oak Hill Mobile Home 81.5
3211822 230’ Oak Hill Mobile Home 81.5
3219212 260’ City of Hudson Oaks (Dyegard) 66.97

(Ref. 5, pp.41&57)

Population calculations: The Oak Hill Mobile Home Water Supply ’s two wells serve a total
of 163 people (Ref. 4, p. 26). Th e City of Hudson Oaks well is a former Dyegard well (Ref. 43, p. 1). The former Dyegard system includes eight interconnected active drinking water
wells. No one well contributes more than 40%. The former Dyegard system serves 178
connections. 178 /8 = 22.25 connections per w ell . 22.25 x 3.01 average household = 66.97 people served per former Dyegard well

.

T he total population served from the 0.25 to 0.5

- mile range is 230

. Additional wel ls were
identified within the 0.25 to 0.5

- mile radius; however, insufficient dat a was available to evaluate potential contamination.Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 41 0.5 to 1

- mile
In the 0.5 to 1

- mile range from the site, the following PWS wells are located:

State Well # D epth PWS People Served
3219302 257’ City of Willow Park 272.48
321 9303 25 0’ City of Willow Park 27 2 .48
3219210 253’ City of Hudson Oaks (Dyegard) 66.97
3211803 240’ City of Hudson Oaks 129 .96
3211819 200’ City of Hudson Oaks 129 .96
3211829 310’ City of Hudson Oaks 129 .96
3219204 255’ City of Hudson Oaks 129 .96
3219205 196’ City of Hudson Oaks 129 .96
3219206 225’ City of Hudson Oaks 129 .96
3219207 220’ City of Hudson Oaks 129 .96
3219208 220’ City of Hudso n Oaks 129 .96
3219211 275’ City of Hudson Oaks 129

. 9 6

(Ref. 5, pp. 38,40

- 42&56

- 58)

Population calculations:

See city of Willow Park and City of Hudson Oaks Dyegard calculations in 0.25 to 0.5

- mile
radius discussion. The City of Hudson Oaks is separate from the former Dyegard system and
has 17 active wells supplying water to 734 connections or an average of 43 connections serving 129 .96 people per well. The 310 foot depth well draws from the Paluxy formation (Ref. 43, p. 1).

The total population served from the 0.5 to 1

- mile range is 1

, 782

. Additional wells were
identified within the 0.5 to 1

- mile radius; however, insufficient dat a was available to evaluate potential contamination.

1 to 2

- mile
In the 1 to 2

- mile range from the site, the following PWS wells are located:

State Well # D epth PWS People Served
32 11902 183 ’ City of Willow Park 272.48
3211 904 260’ City of Willow Park 272.48
3211 905 190 ’ City of Willow Park 272.48
321 1 9 06 260’ City of Willow Park 272.48
3211802 260’ City of Hudson Oaks 129 .96
3211827 260’ City of Hudson Oaks 129 .96
3211828 230’ City of Hudson Oaks 129 .96
3219203 208’ City of Hudson Oaks 129 .96

(Ref. 5, pp. 38,41

- 43&56)Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 42 Population calculations: See 0.5 to 1

- mile section population calculations above.

The total population served from the 1 to 2

- mile range is 1

, 610

. Additional wells were
identifie d within the 1 to 2

- mile radius; however, insufficient dat a was available to evaluate potential contamination.

2 to 3

- mile
In the 2 to 3

- mile range from the site, the following PWS wells are located:

State Well # depth PWS People Served
3211 806 1 43 ’ City of Willow Park 272.48
3211 807 156 ’ City of Willow Park 272.48
3211 809 183 ’ City of Willow Park 272.48
3211 810 179 ’ City of Willow Park 272.48
32118 16 174 ’ City of Willow Park 272.48
32118 1 7 1 60’ City of Willow Park 272.48
32118 1 8 15 3’ City of Willow Park 272.48
321 1825 182 ’ City of Willow Park 272.48
3211907 290’ City of Willow Park 272.48
3219310 306’ City of Willow Park 272.48

(Ref. 5, pp, 38

- 41&43)

Population calculations: See 0.5 to 1

- mile section population calculations above.

The total population served from the 2 to 3

- mile range is 2, 725

. Additional wells were
identified within the 2 to 3

- mile radius; however, insufficient dat a was available to evaluate potential contamination.

3 to 4

- mile
No PWS wells drawing from the Paluxy formation of the Trinity aquifer are located within
the 3 to 4

- mile of the site

.

As specified in the HRS (Ref. 1, p. 51604), the number of people served by drinking water
wells was determined within each “ Other Than Karst ” distance category and a distance

weighted population value for each distance category was assigned. The distance weighted population values were summed for a total of 1,597 , which was divided by 10 and rounded to the nearest integer, for a product of 160 (See Table 12 of this HRS document)

.

# μ

Circle Court
Groundwater Plume Parker County, Texas
TXN000606965

! .

! .

! . ! .

! . ! .

!

. ! . ! .

! .

! .

! . ! .

! . ! .

! . ! . ! .

!

. ! .

! . ! . ! . ! .

! . ! . ! . ! . ! . ! . ! .

! .

! . ! .

! . ! . ! .

! . ! .

! .

! . ! .

! . ! . ! . ! . ! . ! . ! .

! .

! . ! . ! . ! .

! . ! .

! .

! .

! . ! .

! . ! . ! . ! . ! . ! .

! .

! . ! . ! .

! . ! . ! . ! . ! .

! .

! . ! . !

.

! . ! . ! . ! . ! . ! . ! .

! .

! . ! .

! . ! . ! . ! .

! .

!

. ! . ! . ! .

! . ! .

! .

! . ! .

! . ! . ! . ! . ! . ! .

! .

! . ! .

! . ! . ! .

! . ! . ! .

! . ! .

! . ! . ! .

! . ! . ! . ! .

! . ! .

! .

! .

! .

! . ! . ! .

! .

! .

! . ! .

! .

! . !

.

! . ! . ! .

! . ! . ! . ! . ! . ! .

! . ! .

! . ! .

!

. ! . ! .

! . ! . ! .

! . ! . ! . ! . ! . ! . ! . ! . ! . ! . ! . ! . ! . ! . ! .

! . ! . !

. ! . ! . ! .

! .

! .

! . ! . ! . ! . ! .

! . ! . ! .

! . ! . ! . ! . ! .

! .

! . ! . ! .

! . ! . ! . ! .

! . ! . ! . ! .

! .

! .
! . ! . ! .

! . ! . ! . ! . ! .

! . !

.

! . ! . ! . ! .

! . ! .

! . ! . ! . ! . ! .

! . ! . ! .
! . ! .

! .

! .

! .

! . ! .

! . ! .

! . ! .

! . ! . ! .

! .

! . ! .

! . ! .

! . ! .

! . ! .

! . ! .

! .

! . ! . ! .

! .

! . ! . ! . ! .

! . ! . ! .

! . ! .

! .

! . ! . ! .

!

. ! . ! . ! .

! . ! . ! .

! . ! .

9 10 11 This Co 

## enter.

Miles m or in engin on-th 0 1 2 3 4 5 6 7 8 

## Distance rings placed at 0.25, 0.50, 1.00, 2.00, 3.00 and 4.00-mile intervals from the site c

map was generated by the Remediation Division of the Texas

m ission on Environmental Quality. It is intended for illustrative formational purposes only, and is not suitable for legal, eering, or survey purposes. This map does not represent an e-ground survey conducted by or under the supervision of a registered professional land surveyor. In cases where property boundaries are shown, it only represents their approximate relative location. No claims are made to the accuracy or completeness of the data or to its suitability for a particular use. For more information concerning this map, contact the Remediation Division at 800-633-9363. 

# Figure 5: Drinking Water Wells by Distance Radii

The base data set is UTM Zone 14, 0.5 Meter Resolution, Natural Color, NAD 1983. Texas Water Development Board (TWDB) data and Submitted driller's reports available from http://wiid.twdb.state.tx.us. Note: Some wells have geographic coordinants that vary between data sets. For the actual/potential counts in the HRS text, attribute tables were compared to ensure each well was only counted once. 

### Legend

! . Public Water Supply Wells

! . TWDB Groundwater Data

Groundwater Sample Locations

! . Potential Contamination

! . Level 1 Concentration

Parker County ! . ! . ! .

! . ! .

! . ! .

! . ! .

! .

! . ! . ! .Hazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 44 Table 12: Potential Contamination

Distance (Miles) Potentially Contaminated PWS Wells (State Well IDs) Potentially
Contaminated

Population Weighted Population Ref.

0 to 0.25 None 0 0

0.25 to 0.5 3 wells (3211821, 3211822, & 3219212) 230 102 Ref. 5, pp. 41
& 57

0.5 to 1 15 wells (3219302, 3219303, 3211804, 3211820, 3211824, 3219210, 3211803, 3211819, 3211829, 3219204, 3219205, 3219206, 3219207, 3219208, & 3219211) 1,782 523 Ref. 5, pp. 38,
40

- 42 &
56

- 58

1 to 2 8 wells (3211902, 3211904, 3211905, 3211906, 3211802, 3211827, 3211828, & 3219203) 1,610 294 Ref. 5, pp. 38,
41

- 43 &
56

2 to 3 10 wells (3211806, 3211807, 3211809, 3211810, 3211816, 3211817, 3211818, 3211825, 3211907, & 3219310) 2,725 212 Ref. 5, pp, 38

- 41 & 43

3 to 4 None 0 0
Total 6, 3 47 1,131

3.3.3 Resources

No r esources, as defined in HRS Section 3.3.3, were documented for the Paluxy formation of the Trinity aquifer (Ref. 1)

.

3.3.4 Wellhead Protection Area

The Wellhead Protection Area (WPA) has not been evaluated at this time. Potential Contamination Factor Value: 113

Resource Factor Value: 0

Wellhead Protection Area Factor Value: NEHazard Ranking System Documentation Record Circle Court Ground W ater Plume March 2012 TXN 000 606 965 45 3.3.5 Calculation of Targets Factor Category Value

The target factor category value is calculated by determining the sum of the factor values for the nearest well (50), population ( 2

, 9 8 8 .3 ), resources ( 0 ), and WPA (0) (Ref. 1, Section 3.3.5).

Calculations: 50 + 2

, 9 8 8 .3 + 0 + 0 = 3

, 038 .3

3.4 Ground W ater Migration Score for an Aquifer

The ground water migration score for an aquifer is calculated by multiplying the factor category values for likelihood of release (550), waste characteristics ( 18 ), and targets ( 3

, 038 .3 ). Divided by 82,500, the resulting value (maximum value 100) is assigned as the ground water migration pathway score (Ref. 1, Section 3.4).

Calculations: (550 x 18 x 3

, 038 .3 ) / 82,500 = 364.5 9 6 (100 maximum)

3.5 Calculation of Ground W ater Migration Pathway Score

The ground water migration pathway score is calculated by assigning the highest ground water migration score for the aquifer being evaluated (100).

3.5.1 Calc ulation of HRS Site Score

The HRS site score is calculated by using the root

- mean

- square equation which squares each pathway score then takes the sum of all pathways and divides the sum by 4 then takes the square root which is the site score (Ref. 1, Sect ion 2.1.1).

Calculations:

GW Pathway [100] = 10,000 Pathway Squares

SW Pathway not scored = 0 Soil Pathway not scored = 0 Air Pathway not scored = 0

S gw + S sw + S
s + S
a = 10,000 + 0 + 0 + 0 = 10,000 10,000 / 4 = 2,500

√ 2,500 = 50.00

HRS Site Score: 50.00