HRS DOCUMENTATION RECORD COVER SHEET 

Name of Site: Washington County Lead District– Furnace Creek 

EPA ID No.: MON000705842 

Contact Persons

EPA Contact: Michelle Quick 

 U.S. Environmental Protection Agency, Region 7 

 901 North 5th Street 

 Kansas City, Kansas 66101 

 (913) 551-7335 

Documentation Record: Kumud Pyakuryal, Tetra Tech EM Inc. 

Pathways, Components, or Threats Not Scored

Although evidence of soil and ground water contamination exists, the Ground Water Migration, Soil 

Exposure, and Air Migration Pathways are not scored because the listing decision is not significantly 

affected by those pathways (Ref. 7, pp. 8-10, 20, 1079-1534). The air migration pathway was not scored, 

because its score will not affect the NPL listing decision. 

 
HRS DOCUMENTATION RECORD 

Name of Site: Washington County Lead District – Furnace Creek 

EPA Region: 7 

Date Prepared: October 2010 

Street Address of Site*: Approximately 2.0 miles north of the intersection of the Big River and 

Highway 21 (see Figure 1 in Reference 12 and Figure 2 Reference 13) 

City, County, State, Zip Code: Caledonia, Washington County, Missouri 63631 

General Location in the State: The site is located in the Southwest 1⁄4 of Jefferson County, Missouri 

(Ref. 3, p. 1; 12, p. 1). 

Topographic Map: The location of site is shown on the, U.S. Geological Survey, 7.5-Minute 

Series Topographic Map for Belgrade, Missouri Quadrangle and 

Irondale, Missouri Quadrangle (Ref.3). 

Latitude and Longitude*: 37° 50’ 25.91’’ North and 90° 47’ 58.40’’ West 

The latitude and longitude coordinates listed above specify the approximate center of Source 1(Furnace 

Creek Tailings Pile) presented in Figure 1 in Reference 12 and topographic maps included in Reference 3. 

Scores 

Air Pathway Not Scored 

Ground Water Pathway Not Scored 

Soil Exposure Pathway Not Scored 

Surface Water Pathway 100.00 

HRS SITE SCORE 50.00 

* - The street address, coordinates, and contaminant locations presented in this HRS documentation 

record identify the general area in which the site is located. They represent one or more locations EPA 

considers to be part of the site based on the screening information EPA used to evaluate the site for NPL 

listing. EPA lists national priorities among the known "releases or threatened releases" of hazardous 

substances; thus, the focus is on the release, not precisely delineated boundaries. A site is defined as 

where a hazardous substance has been "deposited, stored, 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 Liability Act. Accordingly, EPA contemplates that the preliminary description of 

facility boundaries at the time of scoring will be refined as more information is developed as to where the 

contamination has come to be located. 

 1 
WORKSHEET FOR COMPUTING HRS SITE SCORE

 S S2

 

1. Ground Water Migration Pathway Score (Sgw) 

(from Table 3-1, line 13) 

 NS NS

2a. Surface Water Overland/Flood Migration Component 

 (from Table 4-1, line 30) 

 100.00 

2b. Ground Water to Surface Water Migration Component 

 (from Table 4-25, line 28) 

 0.00 

2c. Surface Water Migration Pathway Score (Ssw) 

Enter the larger of lines 2a and 2b as the pathway score. 

 100.00 10,000 

3. Soil Exposure Pathway Score (Ss) 

(from Table 5-1, line 22) 

NS NS

4. Air Migration Pathway Score (Sa) 

(from Table 6-1, line 12) 

NS NS

5. Total of Sgw

2

 + Ssw2 + Ss

2

 + Sa

2 10,000 

6. HRS Site Score Divide the value on line 5 

by 4 and take the square root 

 50.00

Note: 

NS Not Scored

 2 
TABLE 4−1 

SURFACE WATER OVERLAND/FLOOD MIGRATION COMPONENT SPREADSHEET 

Factor Categories and Factors Maximum 

Value 

Value 

Assigned 

Drinking Water Threat

Likelihood of Release:

1. Observed Release ............................................................................................................. 

2. Potential to Release by Overland Flow: 

2a. Containment ............................................................................................................ 

2b. Runoff ..................................................................................................................... 

2c. Distance to Surface Water ....................................................................................... 

2d. Potential to Release by Overland Flow (lines 2a[2b+2c])....................................... 

3. Potential to Release by Flood: 

3a. Containment (Flood) ............................................................................................... 

3b. Flood Frequency...................................................................................................... 

3c. Potential to Release (lines 3a×3b) ........................................................................... 

4. Potential to Release (lines 2d+3c, subject to a maximum of 500).................................... 

5. Likelihood of Release (higher of lines 1 and 4)................................................................ 

550 

10 

25 

25 

500 

10 

50 

500 

500 

550 

550 

— 

— 

— 

— 

— 

— 

— 

— 

550 

Waste Characteristics:

6. Toxicity/Persistence ......................................................................................................... 

7. Hazardous Waste Quantity............................................................................................... 

8. Waste Characteristics ....................................................................................................... 

(a) 

(a) 

100 

— 

— 

— 

Targets:

9. Nearest Intake................................................................................................................. 

10. Population 

10a. Level I Concentrations........................................................................................... 

10b. Level II Concentrations......................................................................................... 

10c. Potential Contamination ........................................................................................ 

10d. Population (lines 10a+10b+10c) ........................................................................... 

11. Resources ....................................................................................................................... 

12. Targets (lines 9+10d+11) ............................................................................................... 

50 

(b) 

(b) 

(b) 

(b) 

5 

(b) 

— 

— 

— 

— 

— 

— 

— 

Drinking Water Threat Score:

13. Drinking Water Threat Score ([lines 5x8x12]/82,500, subject to a minimum of 100)... 100 NS 

Human Food Chain Threat

Likelihood of Release:

14. Likelihood of Release (same value as line 5) ................................................................. 550 550 

Waste Characteristics:

15. Toxicity/Persistency/Bioaccumulation........................................................................... 

16. Hazardous Waste Quantity ............................................................................................. 

17. Waste Characteristics .....................................................................................................

(a) 

(a) 

1,000 

5×106

1×104

320 

Targets:

18. Food Chain Individual.................................................................................................... 

19. Population 

19a. Level I Concentrations........................................................................................... 

19b. Level II Concentrations......................................................................................... 

19c. Potential Human Food Chain Contamination........................................................ 

19d. Population (lines 19a+19b+19c) ........................................................................... 

20. Targets (lines 18+19d)....................................................................................................

50 

 (b) 

 (b) 

 (b) 

 (b) 

 (b) 

45 

0 

0.03 

0 

0.03 

45.03 

Human Food Chain Threat Score:

21. Human Food Chain Threat Score ([lines 14×17×20]/82,500, 

subject to a maximum of 100)........................................................................................ 100 96.06 

 3 
TABLE 4−1 (Continued) 

SURFACE WATER OVERLAND/FLOOD MIGRATION COMPONENT SPREADSHEET 

 4 

Factor Categories and Factors Maximum 

Value 

Value 

Assigned 

Environmental Threat

Likelihood of Release:

22. Likelihood of Release (same value as line 5) ................................................................. 550 550 

Waste Characteristics:

23. Ecosystem Toxicity/Persistence/Bioaccumulation......................................................... 

24. Hazardous Waste Quantity ............................................................................................. 

25. Waste Characteristics .....................................................................................................

(a) 

(a) 

1,000 

5×107 

10,000 

560 

Targets:

26. Sensitive Environments 

26a. Level I Concentrations........................................................................................... 

26b. Level II Concentrations......................................................................................... 

26c. Potential Contamination ........................................................................................ 

26d. Sensitive Environments (lines 26a+26b+26c)....................................................... 

27. Targets (value from line 26d) ......................................................................................... 

(b) 

(b) 

(b) 

(b) 

(b) 

NS 

25 

NS 

25 

25 

Environmental Threat Score:

28. Environmental Threat Score ([lines 22×25×27]/82,500, subject to a 

maximum of 60)............................................................................................................. 60 60 

Surface Water Overland/Flood Migration Component Score for a Watershed

29. Watershed Score (lines 13+21+28, subject to a maximum of 100)................................ 100 100.00 

Surface Water Overland/Flood Migration Component Score

30. Component Score (Sof)

c

 (highest score from line 29 for all watersheds evaluated, 

subject to a maximum of 100)........................................................................................ 100 100.00 

Notes: 

a Maximum value applies to waste characteristics category 

b Maximum value not applicable 

c Do not round to highest integer 

NS Not scored 
 REFERENCES 

Reference 

Number Description of the Reference 

1 

U. S. Environmental Protection Agency (EPA). 1990. Hazard Ranking System, Final Rule, 40 CFR 

Part 300, Volume 55, No. 241. December 14. Excerpt. 2 Pages. Note: A complete copy of the rule 

is available at http://www.epa.gov/superfund/sites/nplhrsres/index.htm or from the Region 7 Docket 

upon request. 

2 EPA. 2004. Superfund Chemical Data Matrix. January. Excerpt. 13 Pages. A complete copy of 

SCDM is available at http://www.epa.gov/superfund/sites/npl/hrsres/tools/scdm.htm.

3 U. S. Geological Survey (USGS). 7.5 minute series Topographic Quadrangle Maps of Missouri: 

1981, Belgrade (1958), Scale 1:24,000. 1 Sheet. 

4 U.S. Environmental Protection Agency (EPA). 2010. Surf Your Watershed. Updated April 20. 

Accessed on line at http://cfpub.epa.gov/surf/ on April 20, 2010. 2 pages. 

5 Tetra Tech. 2010. Field description and documentation of sources evaluated in support of the Site 

Inspection Report, under the EPA START 3 Contract (EP-S7-06-01). March 15. 3 pages. 

6 

Missouri Department of Natural Resources (MDNR). 2009. Seeger, Cheryl, MDNR, to Kumud 

Pyakuryal, Tetra Tech EM Inc. Memorandum: Southeastern Washington County Area Mining 

History and Geology. November 25. 14 pages. 

7 

Tetra Tech. 2009. Removal Site Evaluation Report for WCLD – FC Site. CERCLIS I.D. 

MON000705842. Under the Superfund Technical Assessment and Response (START) 3 Contract 

(EP-S7-06-01). March 9. 1,561 pages. 

8 

Tetra Tech. 2010. Record of Conversation between Dave Gray, Tetra Tech, and George Smith, a 

resident of Mineral Point, Missouri. Subject: Fishing Activities at the Furnace Creek Tailings 

Pond. February 2, 2010. 1 page. 

9 Environmental Toxicology and Chemistry. 2005. Toxicity of Sixty-Three Metals and Metalloids to 

Hyalella Azteca at Two Levels of Water Hardness. 7 pages. 

10 

Tetra Tech. 2010. Record of telephone Conversation between Kumud Pyakuryal, Tetra Tech, and 

Six nearby Property Owners regarding Furnace Creek Tailings Pond (Source 1). February 9. 2 

pages. 

11 

Tetra Tech. 2009. Quality Assurance Project Plan for Site Inspection Activities at Washington 

County Lead District – Furnace Creek (WCLD – FC) in Washington County, Missouri. Under the 

START 3 Contract (EP-S7-06-01). December 14. 19 pages. 

12 Tetra Tech. 2010. Figure 1: Sampling Points and Surface Water Pathway Segments. Under the 

START 3 Contract (EP-S7-06-01). April 21. 1 page. 

13 Tetra Tech. 2010. Figure 2: 15-Mile Target Distance Limit (TDL). Under the START 3 Contract 

(EP-S7-06-01). April 21. 1 page. 

14 EPA Region 7. 2010. Transmittal of Sample Analysis for ASR #4757 for the WCLD – FC SI 

sampling. March 2. 34 pages. 

15 EPA Region 7. 2010. HRS Analysis Results Supplement for ASR #4757 for the WCLD – FC SI 

sampling. March 22. 17 pages. 

16 EPA Region 7. 2010. Transmittal of Sample Analysis for ASR #4876 for the WCLD – FC SI 

sampling. April 15. 7 pages. 

17 Tetra Tech. 2010. Photo Documentation Record of Field Sampling Activities in support of the Site 

Inspection. Under the START 3 Contract (EP-S7-06-01). January. 36 pages. 

18 Wharton, H.M. Barite Ore Potential of Four Tailings Ponds in the Washington County Barite 

District, Missouri. Missouri Geological Survey and Water Resources. 1972. Excerpt. 20 pages. 

19 Tetra Tech. 2010. Field sheets for ASR #4757 for WCLD – FC Site. January. 102 pages. 

20 EPA Region 7. 2010. Chain of Custody for ASR #4757 for WCLD - FC Site. January. 5 pages. 

21 EPA Region 7. 2010. Chain of Custody for ASR #4876 for WCLD - FC Site. April. 1 page. 

22 Tetra Tech. 2010. Field sheets for ASR #4876 for WCLD – FC Site. April. 5 pages. 

23 U.S. Fish and Wildlife Service (USFWS). 2010. National Wetlands Inventory Data for Source 1, 

at: http://www.fws.gov/wetlands/data/Mapper.html. Accessed in April. 4 pages. 

24 United States Department of Agriculture. 2003. Soil Survey of Washington County, Missouri. 

November. Excerpt. 4 pages. 

5 
6 

Reference 

Number Description of the Reference 

25 

MDNR. 2010. Geographic Information System Metadata on Inventory of Mines, Occurrences, and 

Prospects (IMOP) in Missouri, accessed at: 

http://www.dnr.mo.gov/gis/NRDSDEP3.GEOLOGY.IMOP.XML#_spdoinfo. July 26. 5 pages. 

26 

Northern Dynasty Mine. 2010. Pebble Project: Backgrounder, Tailings, and Tailings Management, 

accessed at: http://www.northerndynastyminerals.com/i/pdf/NDM_Backgrounder_Sep05.pdf. 

Accessed on July 27. 4 pages. 

27 MDNR. 2001-2002. Biological Assessment and Fine Sediment Study, Upper Big River, 

Washington County. 60 pages. 

28 Tetra Tech. 2010. Washington County Lead – Furnace Creek Sample Correlation and Cross 

Reference Table. July. 1 page. 

29 

EPA Region 7. 2010. Memo from Larry Marchin, Project Officer of Contract Laboratory Program 

(CLP) to Michelle Quick, EPA Region 7 NPL Coordinator regarding ASR # 4757 and # 4876 

Analysis Protocols. June. 3 pages. 

30 EPA Region 7. 2010. HRS Analysis Results Supplement for ASR #4876 for the WCLD – FC SI 

sampling. August 9. 1 page. 
SITE DESCRIPTION 

The Washington County Lead District - Furnace Creek site investigated by the U.S. Environmental 

Protection Agency to date is located in the southeastern portion of Washington County, Missouri. 

Previous US Environmental Protection Agency (EPA) removal assessment and evaluation reports divided 

the area into Study Areas 22 through 26 (Ref. 7, p. 17). The five study areas were centered on historical 

mining operations identified during a review of (1) the Inventory of Mine Occurrences and Prospects 

(IMOP) database maintained by the Missouri Department of Natural Resources (MDNR) and (2) 

historical plat maps of the area. All areas are primarily rural residential, with a number of commercial 

businesses present, generally along the state highways (Ref. 7, p. 4). Field activities associated with the 

2010 EPA Site Inspection (SI) evaluated various surface water body segments located within the greater 

Big River watershed (Big Watershed -- 07140104) in the general site vicinity (Ref. 4, pp. 1-2); however, 

the focus of the Hazard Ranking System (HRS) scoring of the Washington County Lead District - 

Furnace Creek is centered on the 71-acre Furnace Creek tailings pile (Source 1) (Ref. 6, p. 11; 12, p. 1; 

13, p. 1). 

The first written record of a lead mine in Missouri was made in 1700 by Father James Gravier, S.J., who 

noted a lead mining region in what is now Washington County. The first period of continuous lead 

mining in Missouri began in 1721, when Phillipe Francois Renault brought slave labor into the area north 

of Potosi in order to mine the surface and near-surface lead ores. Numerous small mines rapidly opened 

throughout Washington County and produced as much as 1,500 pounds of ore per day. Activity tapered 

off after 20 years, with only intermittent production until 1799. Ore was generally covered from shallow 

pits; the deepest known shaft in southeastern Washington County is 115 feet. Mining was often done by 

farmers who operated small mines during the winter to supplement their income. In 1818, H.R. 

Schoolcraft noted of Washington County that there were a great number of "old diggings" in the area 

(Ref. 6, p. 1). 

Early lead miners discarded the barite in waste piles, as it originally had few uses. It became valuable 

after the Civil War, when it was used as a long-lasting white pigment. In the early 1900s, several 

thousand people mined barite and lead in Washington County. Small pits and hand mining gave way in 

1924 to mechanized mining. Barite mining boomed in 1926, when the mineral was discovered to be a 

useful weighting agent in oil drilling mud. Washington County was the world leader in barite production 

for a number of years; production started to decline in 1985 due to competition from Nevada and overseas 

operations (Ref. 6, p. 1). 

Source 1 is located in Study Area 22, which is located in the central portion of the five study areas and 

covers sections of South State Highway 21 and Furnace Creek and Younker Roads. Source 1 is a 

documented fishery where individuals consume their catches (Ref. 5, p. 1; 8, p. 1; 10, pp. 1-2). Although 

identified as an intermittent on the U.S. Geological Survey (USGS) topographic quadrangle, an unnamed 

stream was observed flowing south-southeasterly for about 1.5 miles from the southwestern portion of 

Source 1 toward Furnace Creek; Furnace Creek merges with the Big River approximately 1.25 miles 

downstream from the confluence of the unnamed creek and Furnace Creek (Ref. 3, p. 1; 5, p. 1). Based 

on actual field observations and documented in photographs, Source 1 and the extending unnamed creek 

from its southwestern portion, within the surface water target distance limit (TDL) are perennial (Ref. 13, 

p. 1; 17, pp. 1, 4, 5). The remainder of the TDL is located in the Big River (Ref. 13, p. 1). 

Washington County is located in East Central Missouri. It is bordered on the north by Franklin County, 

on the east by Jefferson and St. Francois Counties, on the south by Iron County, and on the west by 

Crawford County. The climate in Washington County, Missouri, is characterized by cool winters and hot 

summers. The average daily maximum temperature is 88 degrees Fahrenheit (°F) in the summer and 

 7 
31°F during the winter. The mean annual precipitation is about 39.33 inches, with 47 percent 

(18.7 inches) falling between April and September (Ref. 24, pp. 3-4). 

Existing analytical data for the Washington County Lead District – Furnace Creek site being evaluated in 

support of this HRS documentation record and its surrounding mining related investigations include data 

obtained by EPA and MDNR at different dates. A comprehensive removal assessment (RA) report and 

the 2010 Site Inspection (SI) are ongoing. The continuing RA is outside of the 2010 Site Inspection (SI) 

(Ref.5; 14; 16; 29). 

MDNR conducted a macroinvertebrate bioassessment and fine sediment study of the upper Big River in 

Washington County in 2001 and 2002. The study found a Furnace Creek area mine had contributed 

dissolved barium and copper to Big River (Ref. 27, p. 25-26). 

EPA conducted a Site Inspection (SI) at the site in 2010. The general SI objective was to further evaluate 

the nature of contaminants associated with potential source areas at the Washington County Lead District 

– Furnace Creek site and its surroundings based on the IMOP database. Samples were collected in 

January and April 2010 as part of the SI. Soil samples collected from the 72-acre Furnace Creek Tailings 

Pile (Source 1) – Soil 1, Soil 2, Soil 3, and Soil 4 – contained arsenic at concentrations ranging from 3.15 

to 133 milligrams per kilogram (mg/kg); barium at concentrations ranging from 1,940 J to 5,180 J mg/kg 

(“J” denotes an estimated value); copper at concentrations ranging from 6.21 to 17.3 mg/kg; lead at 

concentrations ranging from 88.3 J to 67,000 J mg/kg; and zinc at concentrations ranging from 49.7 to 

115 mg/kg (Ref. 11, p. 8; 12, p. 1; 14, pp. 3, 6, 7 8; 15, p. 1; 19, pp. 1-4; 20, p. 4). Additional surface 

water samples water samples (4876-101, 4876-102, and 4876-103) were collected from it during April 

2010. In these samples, no arsenic or cadmium was reported above the detection limit; barium was 

reported at concentrations ranging from 921 to 967 μg/L; and lead was reported at concentrations ranging 

from 2.87 J to 5.73 J μg/L (Ref. 11, p. 8; 16, pp. 3, 5, 6; 21, p. 1; 22, p. 3-5). Past mining activities have 

impacted Source 1, which is a documented fishery and sensitive environment (wetland) subject to Level II 

contamination (Ref. 8, p.1; 10, pp. 1-2; 23, pp. 1-4). 

 

8 
2.2 SOURCE CHARACTERIZATION 

2.2.1 SOURCE IDENTIFICATION 

Name of Source: Furnace Creek Tailings Pile 

Number of Source: 1 

Source Type: Pile 

Description and Location of Source (with reference to a map of the site): Source 1 (Furnace Creek 

Tailings Pile) is depicted on Figures 1 and 2 (Ref. 12, p. 1; 13, p. 1). The Furnace Creek Plant itself, 

however, is located at a different location in Washington County; based on the information provided by 

the MDNR it was operated by Holly Mining Company and was logged separately in the IMOP database 

(Ref 6, p. 10). The IMOP database is based upon the U.S. Bureau of Mines Mineral Industry Location 

System (MILS) database for Missouri. The majority of its information was updated in the late 1970s and 

early 1980s (Ref. 25, p. 1). Source 1 location is noted in the Public Land Survey System (PLSS) format 

in Table 1 (Ref. 6, pp. 1, 4, 5, 11). The geographic coordinates for the approximate center of the tailings 

pond, Source 1, are 37° 50’ 25.91’’ North and 90° 47’ 58.40’’ West (Refs. 3; 12, p. 1; 13, p. 1). 

Evidence observed during the 2010 Site Inspection field activities indicated that no engineering controls 

or containment features were present at the tailings pond (Ref. 17, pp. 1-4). 

Table 1 

Name Description Commodity Acres Status 

Furnace 

Creek 

Tailing 

Pond 

Furnace Creek Tailings Pond 

Southern 1⁄2 of Southeastern 1⁄4 of 

Section 24 Township 36 North and 

Range 10 East 

Barite 71 Tailings pond - water 

Processing area - idle 

Source: Ref. 3, p. 1; 6, p. 11; 17, pp. 1-4 

Contaminants commonly associated with mining districts are heavy metals. Hazardous metals, arsenic, 

barium, copper, lead, and zinc were found at Source 1 during the SI investigation (Ref. 14, pp. 6, 8; 15, 

p. 1). Observations documented during sampling efforts indicated materials found in Source 1 were mine 

tailings including tiff materials (Ref. 5, p. 1; 22, p. 1-2). In addition, Reference 12 depicts the footprint of 

Source 1, as documented by MDNR during its 208 Strategy Study from 1982. Features associated with 

the area were mapped by the Missouri Division of Geology and Land Survey (DGLS) and department of 

Environmental Quality (DEQ) in the early 1980s as part of a project referred to as the 208 project. The 

208 project was completed in 1982, and it delineated areas of non-coal mined lands, tailings ponds and 

plant areas. These maps were developed from topographic maps, orthophoto quadrangles and personal 

communications. The maps were digitized using a commercial GIS system, using the topographic base as 

a guide. While improving the coverage over that derived from the topographic maps, these maps also 

pre-dated cessation of barite mining in the area (Ref. 6, pp. 4-6). 

The first written record of a lead mine in Missouri was made in 1700 by Father James Gravier, S.J., who 

noted a lead mining region in what is now Washington County. The first period of continuous lead 

mining in Missouri began in 1721, when Phillipe Francois Renault brought slave labor into the area north 

of Potosi in order to mine the surface and near-surface lead ores. Numerous small mines rapidly opened 

throughout Washington County and produced as much as 1,500 pounds of ore per day. Activity tapered 

off after 20 years, with only intermittent production until 1799. Ore was generally covered from shallow 

pits; the deepest known shaft in southeastern Washington County is 115 feet. Mining was often done by 

9 
10 

farmers who operated small mines during the winter to supplement their income. In 1818, H.R. 

Schoolcraft noted of Washington County that there were a great number of "old diggings" in the area 

(Ref. 6, p. 1). 

Early lead miners discarded the barite in waste piles, as it originally had few uses. It became valuable 

after the Civil War, when it was used as a long-lasting white pigment. In the early 1900s, several 

thousand people mined barite and lead in Washington County. Small pits and hand mining gave way in 

1924 to mechanized mining. Barite mining boomed in 1926, when the mineral was discovered to be a 

useful weighting agent in oil drilling mud. Washington County was the world leader in barite production 

for a number of years; production started to decline in 1985 due to competition from Nevada and overseas 

operations (Ref. 6, p. 1). 

This source is being evaluated as “pile” because it was designed and used as a disposal site for tailings 

processed by washer plants (Ref. 18, pp. 7-9). These disposal ponds allowed the tailings to dewater, but 

they were not constructed to treat water. Tailings are a mixture of water and finely ground rock that is 

left over once mineral concentrate is removed and permanently stored in large area usually located in a 

natural hollow or valley. Often tailings embankment (barrier) is built of rock and other materials at the 

low end of the valley to contain the tailings material. Once there the finely ground rock and water that 

together make up tailings separate, and when the tailings settle to the bottom, the balance water 

accumulate to from a tailings pond (Ref. 26, pp. 1-2). Whereas, the overburden made up of soil, gravel, 

and loose materials that cover the surface of a mine site are typically stored in large piles and used after 

mining to landscape the area (Ref. 26, p. 1). As shown in pictures included in Reference 17 (Ref. 17, pp. 

1-3), piles and tailings are all in contact with the pond and get inundated during wet weathers (Ref. 5, p. 

1). This source is shown on the Belgrade, Missouri Quadrangles (Refs. 3; 12, Figure 1). Figure 1 

(Reference 12) presents an extrapolated area associated with the tailings pile with overlays showing the 

locations of some surface water and sediment samples collected in relative downgradient locations 

(Ref. 12, p. 1). 
2.2.2 HAZARDOUS SUBSTANCES ASSOCIATED WITH THE SOURCE 

All source samples were collected at Source 1 and contain “wastes” associated tailings piles, and adjacent 

areas that contain comingled resultant overburden. The sampling associated with Source 1 was conducted 

in January and April 2010. Associated results are presented in Table 2 (solids/soil) and Table 3 (surface 

water) below. The samples were collected from the pond (Ref. 12, p. 1) and followed the EPA approved 

Quality Assurance Project Plan (Ref. 11, pp. 2, 8). All data packages for the Washington County Lead 

District – Furnace Creek site (ASR# 4757 and ASR# 4876) were out sourced to a CLP laboratory for the 

metals analyses using the CLP Statement of Work (SOW) ILM05.4 (Ref. 29, p. 1). 

Table 2 

Source 1 Analytical Data 

Washington County Lead District – Furnace Creek, Washington County, Missouri 

Date: January and March 2010 

EPA Sample 

Number/Samp

le Designation 

Sampling 

Depth 

(feet) 

Sample 

Quantitation 

Limit (mg/kg) 

Hazardous 

Substance* 

Concentration 

(mg/kg) Reference 

ASR 4757 (January 2010; Ref. 14) 

4757-1/SOIL 1 1.49 Arsenic 3.15 

4757-1/SOIL 1 29.8 Barium 1,940 J 

4757-1/SOIL 1 3.72 Copper 7.17 

4757-1/SOIL 1 1.49 Lead 88.3 J 

4757-1/SOIL 1 8.93 Zinc 49.7 

Ref. 12, p. 1; 14, pp. 3, 6, 7 

8; 15, p. 1; 19, p. 1; 20, 

p. 4; 28, p. 1; 29, p. 1 

4757-2/SOIL 2 1.14 Arsenic 10.2 

4757-2/SOIL 2 68.6 Barium 3,000 J 

4757-2/SOIL 2 2.86 Copper 17.3 

4757-2/SOIL 2 1.14 Lead 238 J 

4757-2/SOIL 2 6.86 Zinc 115 

Ref. 12, p. 1; 14, pp. 3, 6, 7 

8; 15, p. 1; 19, p. 2; 20, 

p. 4; 28, p. 1; 29, p. 1 

4757-3/SOIL 3 1.01 Arsenic 9.16 

4757-3/SOIL 3 60.9 Barium 3,260 J 

4757-3/SOIL 3 2.54 Copper 7.45 

4757-3/SOIL 3 1.01 Lead 160 J 

4757-3/SOIL 3 6.09 Zinc 106 

Ref. 12, p. 1; 14, pp. 3, 6, 7 

8; 15, p. 1; 19, p. 3; 20, 

p. 4; 28, p. 1; 29, p. 1 

4757-4/SOIL 4 1.06 Arsenic 133 

4757-4/SOIL 4 106 Barium 5,180 J 

4757-4/SOIL 4 2.65 Copper 6.21 

4757-4/SOIL 4 10.6 Lead 67,600 J 

4757-4/SOIL 4 

0-4 

6.36 Zinc 92.9 

Ref. 12, p. 1; 14, pp. 3, 6, 7 

8; 15, p. 1; 19, p. 4; 20, 

p. 4; 28, p. 1; 29, p. 1 

ASR 4876 (April 2010; Reference 16) 

4876-1/Soil 1 1.63 Arsenic 6.67 

4876-1/Soil 1 32.7 Barium 3,780 

4876-1/Soil 1 1.63 Lead 299 

Ref 16, pp. 3, 5; 21, p. 1; 

22, p. 1; 28, p. 1; 29, p. 1; 

30, p. 1 

4876-2/Soil 2 1.45 Arsenic 10.6 

4876-2/Soil 2 28.9 Barium 3,690 

4876-2/Soil 2 

0-4 

1.45 Lead 227 

Ref 16, pp. 3, 5; 21, p. 1; 

22, p. 2; 28, p. 1; 29, p. 1; 

30, p. 1 

Notes: 

EPA United States Environmental Protection Agency 

11 
J Estimated value: (i) Based on the EPA laboratory validation document, the actual J-coded Barium concentration in 

Table 2 were higher than the reported value (biased low) due to low recoveries of Barium in the laboratory control 

samples as well as concentration may be lower than the reported value (biased high) due to the serial dilution percent 

differences being above the control limits and (ii) the actual J-coded Lead concentration in Table 2 were lower than the 

reported value (biased high) due to the serial dilution percent differences being above the control limits. However, in 

both cases analytes were positively identified (Ref. 14, pp. 6-7). 

mg/kg Milligrams per kilogram 

* Includes a pollutant or contaminant 

Table 3 

Source 1 Analytical Data 

Washington County Lead District– Furnace Creek, Washington County, Missouri 

Surface Water Samples in μg/L 

ASR 4876 (March 2010; Reference 16) 

EPA Sample 

Number/Sample 

Designation 

Sampling 

Depth 

(feet) 

Sample 

Quantitation 

Limit (μg/L) 

Hazardous 

Substance 

Concentration 

(μg/L) Reference 

4876-101/SW 101 10 Barium 921 

4876-101/SW 101 1 Lead 5.73 J 

Ref 11, p. 8; 16, pp. 3, 5; 

21, p. 1; 22, p. 3; 28, p. 1; 

29, p. 1; 30, p. 1 

4876-102/SW 102 10 Barium 965 

4876-102/SW 102 1 Lead 3.96 J 

Ref 11, p. 8; 16, pp. 3, 5; 

21, p. 1; 22, p. 4; 28, p. 1; 

29, p. 1; 30, p. 1 

4876-103/SW 103 10 Barium 967 

4876-103/SW 103 

Not 

Applicable 

1 Lead 2.87 J 

Ref 11, p. 8; 16, pp. 3, 6; 

21, p. 1; 22 p. 5; 28, p. 1; 

29, p. 1; 30, p. 1 

Notes: 

EPA United States Environmental Protection Agency 

J Estimated value; the actual J-coded Lead concentration in Table 3 were higher than the reported value (biased low) due 

to the serial dilution percent difference being above the control limits (Ref. 16, p. 4) 

μg/L Microgram per liter 

NA Not Available 

SW Surface Water 

The sampling was conducted in accordance with EPA Region 7 Standard Operating Procedure (SOP) 

4230.17, SOP 4230.08, and SOP 4231.2012 for surface water, sediment, and soil, respectively. The 

Chain of Custody was maintained as directed by EPA Region 7 SOP 2420.04 and samples were accepted 

according to EPA Region 7 SOP 2420.01 (Ref. 11, p. 5). The review and verification was performed by a 

qualified analyst as described in Region 7 EPA SOPs 2430.06 and 2430.12 (Ref. 11, p. 7). The sediment, 

soil, and water samples were analyzed in accordance to analytical methods as stipulated by EPA Region 7 

SOPs 3122.03, and 3122.4, respectively (Ref. 11, p. 8). The table included in Reference 28 includes 

sample identification numbers in Tables 2 and 3 of this documentation record as they correlate with 

Figure 1 (Reference 12) and Figure 2 (Reference 13); Reference 28 also includes correlating sample 

designations for field sheets and analytical data packages. 

12 
2.2.3 HAZARDOUS SUBSTANCES AVAILABLE TO A PATHWAY 

Table 4 

Source 1 Containment 

Containment Description Containment 

Factor Value Reference 

Gas release to air: - NS -- 

Particulate release to air: - NS -- 

Release via ground water NS -- 

Release via overland migration and/or flood: Source 1 has no maintained 

engineered cover or run on and/or run off control system, functioning 

leachate collection and removal system. 10 

Ref. 1, Table 

4-2; 5, p. 1; 17, 

pp. 1-4; 22, pp. 

1-5 

Notes: 

NS Not Scored 

13 
14 

2.2.4 HAZARDOUS WASTE QUANTITY 

2.4.2.1.1. Hazardous Constituent Quantity 

The information available is not sufficient to evaluate Tier A, as required in Section 2.4.2.1.1 of the HRS. 

As a result, the evaluation of Hazardous Waste Quantity proceeds to evaluate Tier B, hazardous 

wastestream quantity (Ref. 1, p. 51590-51591). 

Hazardous Constituent Quantity Value: NS 

2.4.2.1.2. Hazardous Wastestream Quantity 

The information available is not sufficient to evaluate Tier B, as required in Section 2.4.2.1.2 of the HRS. 

As a result, the evaluation of Hazardous Waste Quantity proceeds to evaluate Tier C, volume 

(Ref.1, p. 51591). 

Hazardous Wastestream Quantity Assigned Value: NS 

2.4.2.1.3. Volume 

The information available is not sufficient to evaluate Tier C, as required in Section 2.4.2.1.3 of the HRS. 

As a result, volume is assigned a value of zero, and the evaluation of Hazardous Waste Quantity proceeds 

to evaluate Tier D, area (Ref. 1, p. 51591). 

Volume Assigned Value: 0 

2.4.2.1.4. Area 

Description

Based on the estimated value provided by MDNR, the area of Source 1 is 71 acres (Ref. 6, p. 11). 

Therefore, based on the HRS Table 2-5 on page 51591, the total acres (71) was multiplied by 43,560 

square feet; the total square feet (3,092,760) was divided by 13 to arrive at the Hazardous Waste Quantity 

Value of 237,904.62. 

Table 5 

Source Type Area Units References 

Pile 3,092,760 Square feet 1, Table 2-5; 6, p. 11 

Sum (ft2

): 3,092,760 

Equation for Assigning Value (Table 2-5): A/13 

 Area Assigned Value: 237,904.62 

(Ref. 1, p. 51591) 

2.4.2.1.5. Source Hazardous Waste Quantity Value 

 Highest assigned value assigned from HRS Table 2-5: 237,904.62 

(Ref. 1, p. 51591) 

NS = Not Scored
SUMMARY OF SOURCE DESCRIPTIONS 

Table 6 

Summary of Source 1 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) 

1 237,904.62 No Not Scored 10 Not Scored Not Scored Not Scored 

Description of Other Possible Sources/Sites

The focus of EPA Region 7 sampling activities in the Washington County Lead District – Furnace Creek 

area has been at residential homes (Ref. 7, pp. 8-10, 20, 1079-1534). Numerous barite tailings ponds are 

found throughout the area; however, only Source 1 has been evaluated as a source in the HRS scoring of 

the Washington County Lead District – Furnace Creek site. Further remedial investigations may be 

warranted to establish inter-watershed contamination. It should be noted, however, tailings ponds were 

generally created near head of valleys, at a higher elevation than the general topography in the area; in 

turn, this placed the tails and process water at higher elevations than the water table for the majority of the 

area. As they are visible in topography based maps, the tailings and process water were often located 

upgradient of major streams in the area, some of which may be losing streams (Ref. 3, pp. 1, 2; 12, p. 1; 

13, p. 2; 6, pp. 1, 9-14). 

In Washington County, a number of tailings piles have been identified but have not yet been sampled to 

characterize the hazardous constituents associated with them. A number of known large former mining 

operations are included in pages 9 through 14 of Reference 6. The EPA Superfund lead investigation 

sampling in Washington County indicates an area-wide surface soil and ground water contamination as 

documented during past EPA Region 7 investigations and listed in Reference 7 (Ref. 7, pp. 8-10, 20, 

1079-1534). For scoring purposes, only Source 1 or Furnace Creek Tailings Pond has been included in 

this HRS evaluation; however, it is important to note that other sources, such as the Irondale Mine Area, 

West Fork Mine Area, Hopewell Mine Area, and Forker Diggings, were sampled during the 2010 SI (Ref. 

5, pp. 1-2). Sample 4757-11 collected at the Irondale Mine area contained lead up to 195,000 J mg/kg 

(Ref. 14, p. 10; 15, p. 2; 12, p. 1) 

In addition to the large operations described above, at one time Washington County was host to hundreds 

and possibly thousands of small mines that were worked by hand (Ref. 6, pp. 1-4). 

15 
4.0 SURFACE WATER MIGRATION PATHWAY 

4.1 OVERLAND/FLOOD MIGRATION COMPONENT 

4.1.1.1 Definition of Hazardous Substance Migration Path for Overland/Flood Component 

The nearby towns and communities are located on the Big watersheds, as defined by USGS Hydrologic 

Unit 07140104. Numerous creeks and rivers drain associated watersheds in this area, primarily draining 

towards the Big River. The Big River is the primary surface water feature in the general vicinity of the 

site (Ref. 3, pp. 1; 4, p. 1-2; 12, p. 1; 13, p. 1). 

For the HRS scoring purposes, documented observed releases to the surface water migration pathway are 

associated with Source 1, which is a pond with a documented fishery and wetland targets; Source 1 is a 

pond meeting the definition of lake for HRS scoring. As such, Source 1 is a documented human food 

chain fishery (Ref. 8, p. 1; 10 pp. 1-2). HRS qualified wetland areas are contained within Source 1 (Ref. 

23, p. 1-3; 12, p. 1). As the source is located within the surface water body being evaluated as a target, 

the probable point of entry (PPE) is identified at the most upstream location of the Source; the PPE is 

depicted on Figure 2 (Reference 13). A perennial unnamed creek exits the source from its southwestern 

portion (Ref. 3; 5, p. 1; 12, p. 1; 13, p. 1). It flows from the pond a distance of 1.5 miles where it joins 

Furnace Creek. Furnace Creek flows south for 1.25 miles where it merges with the Big River. The Big 

River flows east and makes up the remainder of the in-water segment. The 15-mile target distance limit 

(TDL) is near the Washington and St. Francois county line (Ref. 12, p. 1; 13, p. 1). 

16 
4.1.2.1 LIKELIHOOD OF RELEASE 

4.1.2.1.1 Observed Release 

An observed release by direct observation can be documented to the surface water migration pathway. 

Direct Observation

- Basis for Direct Observation 

By definition, the deposition of the tailings containing hazardous substances into a surface water body 

qualifies as an observed release by direct observation to surface water (Ref. 1, Section 4.1.2.1.1, p. 51609; 

Section 2.2.2 and Table 2 of this HRS documentation record). A fishery and wetland are located within 

the boundaries of Source 1 (Ref. 8, p. 1; 10 pp. 1-2; 23). This observed release by direct observation is 

also supported by photographs taken during in January 2010 and the MDNR Strategy 208 Study (Ref. 1, 

Section 4.1.2.1.1, p. 51609; 6, pp. 3-5, 11; 17, pp. 1-4). 

- Hazardous Substances in the Release 

Hazardous substances associated with Source 1 were identified during the January 2010 and April 2010 

sampling data included in References 14, 15, and 16. Analysis of the samples by EPA laboratory 

confirmed the presence of arsenic, barium, copper, lead, and zinc. The analytical data from these samples 

are summarized in Table 2 in Section 2.2.2. 

In accordance with Section 4.1.2.1.1 (Ref. 1, p. 51609), an observed release factor value of 550 is 

assigned below and on line 1 of Table 4-1. Potential to release is not evaluated. 

17 
Attribution

Source 1 is a tailings pile with an associated pond (Ref. 3, p. 1; 6, p. 11; 17, pp. 1-4). Tailings piles 

associated with mining waste are designed and used as disposal sites for tailings processed by washer 

plants (Ref. 18, pp. 7-9). Source 1 contains a documented fishery where individuals consume their 

catches. Source 1 also contains wetlands within its boundary (Ref. 5, p. 1; 8, p. 1; 10, pp. 1-2; 23). 

Hazardous substances associated with Source 1 are arsenic, barium, copper, lead, and zinc. 

Lead and barium mining in the Furnace Creek area of Washington County has a long history dating back 

hundreds of years. The first written record of a lead mine in Missouri was made in 1700 by Father James 

Gravier, S.J., who noted a lead mining region in what is now the Washington County. The first period of 

continuous lead mining in Missouri began in 1721, when Philippe Francois Renault brought slave labor 

into the area north of Potosi, in order to mine the surface and near-surface lead ores. Numerous small 

mines rapidly opened throughout Washington County. In the late 18th and early 19th century mining was 

often undertaken by farmers who operated small mines during the winter to supplement their income. 

Early miners discarded the barite in waste piles, as back then it had little economic value. It became 

valuable after the Civil War, when it was used as a long-lasting white pigment. In the early 1900s, 

several thousand people mined barite and lead in Washington County. Barite mining boomed in 1926, 

when the mineral was discovered to be useful weighting agent in oil drilling mud (Ref. 6, pp. 1). As 

Reference 17 (Ref. 17; pp. 1-2) photographs show there are no liners or engineering controls to mitigate 

release from the source. Mechanized and subsistence hand mining in the site area continued clearly into 

the 20th century. Many of the later large mining companies reworked lands that had experienced hand 

mining for lead or barite, as considerable barite ore remained in the material left between the pits and 

shafts. In some cases, the older pits were used as an exploration guide (Ref. 6, p. 4). A physiochemical 

study conducted by MDNR in 2001/2002 indicated total recoverable barium concentrations near the 

confluence of Furnace Creek and the Big River increased by more than three-fold from the upstream 

stations (Ref. 27, p. 17). The study further concluded that there are few known mines in the upper 

reaches of the Big River (upstream from the confluence of Furnace Creek and the Big River) that may 

influence the river’s community (Ref. 27, pp. 5). 

 Likelihood of Release Value: 550

18 
 

4.1.3.2 Waste Characteristics 

4.1.3.2.1 Toxicity/Persistence/Bioaccumulation 

Table 7 

Hazardous 

Substance 

Source 

Number/

OR 

Toxicity 

Factor 

Value 

Persistence 

Factor 

Value1

Bioaccumulation 

Value2

Toxicity/Persistence/ 

Bioaccumulation 

Factor Value2

(Table 4-16)3

Reference 

Arsenic 1/OR 10,000 1 5 50,000 2, pp. 2, 3 

Barium 1/OR 10,000 1 500 5×106 2, pp. 4, 5 

Copper 1/OR 0 1 500 0 2, pp. 8, 9 

Lead 1/OR 10,000 1 5 50,000 2, pp. 10, 11

Zinc 1/OR 10 1 5.0 50 2, pp. 12, 13

Notes: 

1

 - Persistence factor value for lake was used. 

2

 - Freshwater bioaccumulation factor values were used. 

3

 - Table found in Reference 1, page 51619 

OR Observed Release 

Barium was found at this site at concentrations known to potentially cause adverse effects (Ref. 9, pp. 1, 

4; 2, pp. 4-5; Tables 2 and 3 of the HRS documentation record; Ref. 13; Ref. 14, p. 23). The compound 

with the highest toxicity/persistence/bioaccumulation factor value is barium. Its assigned value of 5×106

is entered below and on line 15 of Table 4-1. 

4.1.3.2.2 Hazardous Waste Quantity 

Table 8 

Source Number 

Source Hazardous Waste Quantity 

Value 

(Section 2.4.2.1.5) 

Is Source Hazardous 

Constituent Quantity Data 

Complete? (yes/no) 

1. Furnace Creek Tailings Pond 237,904.62 no 

Sum of Values: 237,904.62 

A hazardous waste quantity value of 10,000 is selected from Table 2-6 of the HRS (Ref. 1, p. 51591) 

based on the Source Hazardous Waste Quantity Value of 237,904.62. This value is entered below and on 

line 16 of Table 4-1. 

19 
 

20 

4.1.3.2.3 Waste Characteristics Factor Category Value 

A waste characteristics product is computed by multiplying the toxicity/persistence factor value by the 

hazardous waste quantity factor value (the product of which is subject to a maximum of 1 × 108

) and then 

multiplying that number by the bioaccumulation potential factor value. This product (subject to a 

maximum of 1 × 1012) is then entered into Table 2-7 (Ref. 1, p. 51592) to obtain a waste characteristics 

factor category value. Barium yields the highest waste characteristics factor value. 

Toxicity/persistence factor value × hazardous waste quantity factor value: 1 × 108

 10,000 × 10,000 = 1 × 108

(Toxicity/persistence x hazardous waste quantity) × bioaccumulation potential factor value: 5 × 1010

 1 × 108 × 500 = 5 × 1010

 

Waste Characteristics Value: 320 

Therefore, 320 was entered on line 17 of Table 4-1.
 

4.1.3.3 Human Food Chain Threat-Targets 

Furnace Creek Tailings Pond or Source 1 is regularly fished. The total fishery production is unknown but 

is greater than zero because fish are known to be consumed annually (Ref. 8, p. 1; 10, p. 1-2). Hazardous 

substances with a bioaccumulation value of 500 or greater have been documented in this fishery (See 

Section 4.1.3.2.1 of this HRS documentation record). Therefore, it is an HRS-qualified human food chain 

fishery (Ref. 1, Section 4.1.3.3, p. 51620). 

4.1.3.3.1 Food Chain Individual 

There is an observed release of hazardous substances having a bioaccumulation factor value (BCFV) of 

500 or greater to the watershed. A known fishery is subject to Level II actual contamination. Therefore, 

a food chain individual factor value of 45 is assigned. This value is entered on line 18 of the Table 4-1. 

Food Chain Individual Value: 45 

4.1.3.3.2 Population 

4.1.3.3.2.1 Level I Concentrations 

No zone of Level I contamination has been identified for any fishery at this time, because no known fish 

tissue samples have been collected. 

4.1.3.3.2.2 Level II Concentrations 

An observed release by direct observation has been documented in Source 1 (see Section 4.1.2.1.1 of this 

HRS documentation record). Because the PPE to surface water is located in Source 1 and the fishery is 

located wholly within Source 1, the entire fishery is evaluated as actually contaminated at Level II 

concentrations (see HRS Section 4.1.1.2). The total fishery production is unknown but is greater than 

zero because fish are known to be consumed annually; a value of 0.03 is assigned for Level II 

Concentrations Factor Value (Ref. 1, HRS Table 4-18; 8, p. 1). This value is entered on line 9b of Table 

4-1. 

Level II Concentrations Factor Value: 0.03 

4.1.3.3.2.3 Potential Human Food Chain Contamination 

Not scored.

21 
 

4.1.4.2 WASTE CHARACTERISTICS 

4.1.4.2.1 Ecosystem Toxicity/Persistence/Bioaccumulation 

Table 9 

Hazardous 

Substance 

Source 

Number/OR 

Ecosystem 

Toxicity 

Factor Value1

Persistence 

Factor Value3

Ecosystem Toxicity/ 

Persistence Factor Value 

(Table 4-20)2

Reference 

Arsenic 1/OR 10 1 10 2, pp. 2, 3 

Barium 1/OR 1 1 1 2, pp. 4, 5 

Copper 1/OR 1,000 1 1,000 2, pp. 8, 9 

Lead 1/OR 1,000 1 1,000 2, pp. 10, 11 

Zinc 1/OR 10 1 10 2, pp. 12, 13 

Notes: 

1 Freshwater ecotoxicity values used from Reference 2. 

2 Table found in Reference 1, page 51622. 

3 Persistence factor value for lakes used. 

OR Observed Release 

Table 10 

Hazardous 

Substance 

Ecosystem 

Toxicity/ 

Persistence Factor 

Value 

EcoBioaccumulation 

 Factor Value1 

(Section 4.1.4.2.1.3)2

Ecosystem Toxicity/ Persistence/ 

Bioaccumulation 

Factor Value (Table 4-21)3

Arsenic 10 5,000 50,000 

Barium 1 500 500 

Copper 1,000 5,000 5X106

Lead 1,000 50,000 5×107

Zinc 10 50,000 5X105

Notes: 

1 Freshwater bioaccumulation factor values used from Reference 2. 

2 Reference 1, page 51622. 

3 Table found in Reference 1, page 51623. 

An ecosystem toxicity/persistence/bioaccumulation factor value of 50,000,000 (5×107

) is assigned from 

the table above based on lead. This value is entered below and on line 23 in Table 4-1. 

22 
 

4.1.4.2.2 Hazardous Waste Quantity 

Table 11 

Source 

Number 

Source Hazardous Waste 

Quantity Value 

(Section 2.4.2.1.5) 

Is Source Hazardous 

Constituent Quantity Data 

Complete? (yes/no) 

1. Furnace Creek Tailings Pond 237,904.62 no 

Sum of Values: 237,904.62 

A hazardous waste quantity value of 10,000 is selected from Table 2-6 of the HRS rule (Ref. 1, p. 51591) 

based on the Source Hazardous Waste Quantity Value of 237,904.62. This value is entered below and on 

line 24 of Table 4-1 found on page 5 of this documentation record. 

4.1.4.2.3 Waste Characteristics Factor Category Value 

A waste characteristics factor value is computed by first multiplying the ecotoxicity/persistence factor 

value by the hazardous waste quantity factor value (the product of which is subject to a maximum of 

1 × 108

) and then multiplying that number by the bioaccumulation potential factor value. This product 

(subject to a maximum of 1 × 1012) is then entered into Table 2-7 (Ref. 1, p. 51592) to obtain a waste 

characteristics factor category value. Of the hazardous substances in Section 4.1.4.2.1 of the HRS 

documentation record, lead produces the highest value. This value is entered below and on line 25 in 

Table 4-1. 

 Ecosystem toxicity/persistence factor value × hazardous waste quantity factor value: 1 × 107

 1,000 × 10,000 = 1 × 107

 (Ecosystem toxicity/persistence × hazardous waste quantity) × bioaccumulation potential factor 

 value: 5 × 1011

 1×107 × 50,000 = 5 ×1011 

Waste Characteristics Factor Value: 560 

23 
 

4.1.4.3 ENVIRONMENTAL THREAT - TARGETS 

4.1.4.3.1 Sensitive Environments 

4.1.4.3.1.1 Level I Concentrations 

No zones of Level I contamination have been identified. 

4.1.4.3.1.2 Level II Concentrations 

An observed release by direct observation has been documented in Source 1 (see Section 4.1.2.1.1 of this 

HRS documentation record). Because the PPE to surface water is located in Source 1 and the wetland is 

located wholly within Source 1, the wetland is evaluated as actually contaminated at Level II 

concentrations (see HRS Section 4.1.1.2). 

Wetlands 

A USFWS defined wetland is located in Source 1 (Refs. 23, pp. 1-2). Wetlands on the eastern and 

western portion of the source have been classified by the USFWS as follows: 

• Wetland on the eastern side of Source 1: PEMCh -- Palustrine, Emergent, Seasonally 

Flooded, Diked/Impounded, (Ref. 23, pp. 2-3). 

• Wetland on the western side of Source 1: PEMFh -- Palustrine, Emergent, Semipermanently 

Flooded, Diked/Impounded, (Ref. 23, pp. 2-3). 

Table 12 

Wetland Wetland Frontage Reference 

Perimeter of the wetland (east) 983.23 feet (0.19 mile) 23, p. 1, 4 

Perimeter of the wetland (west) 2,736.58 feet (0.52 mile) 23, p. 1, 4 

Total Wetland Frontage: 3,719.81 (0.71 mile) 

A wetland value is assigned from Table 4-24 (Ref. 1, p. 51625). 

 Wetland Value: 25 

 Sum of Sensitive Environments Value + Wetland Value: 25 

This value is entered below and on Table 4-1 line 26b. 

Sensitive Environments Level II Value: 25 

4.1.4.3.1.3 Potential Contamination 

Potential targets in were not scored because they do not contribute significantly to the pathway score. 

24