PUBLIC HEALTH ASSESSMENT
Evaluation of Leviathan Mine Site
LEVIATHAN MINE
MARKLEEVILLE, ALPINE COUNTY, CALIFORNIA
The Leviathan Mine Site was originally mined for copper sulfate in 1863. In the 1950s and 1960s, the site was mined for sulfur by open-pit, strip-mining methods. The contamination source area for the site is the approximately 22 million tons of crushed rock containing high levels of sulfur ore spread over the site. Liquids flowing from the waste piles and tunnels at the site are best described as AMD.
AMD from Leviathan Mine has caused significant contamination to Leviathan, Aspen, and Bryant creeks, as well as the River Ranch Irrigation Channel. Seven COCs (aluminum, arsenic, cadmium, iron, manganese, nickel and thallium) have been detected in surface water and sediment downstream from the mine. The contaminated waters and sediment are the source of two completed exposure pathways and eight potentially completed pathways.
Past and present consumption of surface waters in areas downstream of Leviathan Mine are considered completed exposure pathways because of the health risks from exposure to arsenic contamination. Swimming and wading are also considered completed exposure pathways because of the health risks from past or present exposure to arsenic. These two pathways are also considered completed in the future in Leviathan and Aspen creeks, but are considered potentially completed in areas further downstream of the mine (Bryant Creek & River Ranch Irrigation Channel) due to improving surface water conditions.
Potentially completed exposures include consumption of fish, plants and wild game collected near Leviathan Mine, eating beef raised on the River Ranch, inhalation of dust near the mine, and future exposure to surface water and sediments via drinking, swimming and wading in Bryant Creek and the River Ranch Irrigation Channel.
The available data indicate that the completed pathways could result in cancerous and non-cancerous health effects. The estimated cancer risks from these exposures range from no apparent increased risk to moderate increased risk of cancer depending on where, when, and how long the exposures occur. Arsenic represents the most significant risks to individuals exposed to surface water and sediment impacted by Leviathan Mine.
In general, the closer one gets to Leviathan Mine, the greater the probability that concentrations of contaminants will present a health risk. Avoiding contact with mine tailings, surface water, and sediments in Leviathan, Aspen, and Bryant creeks, as well as the River Ranch Irrigation Channel, will reduce health risks associated with exposure to contaminants from Leviathan Mine. Based on the completed pathways, the estimated exposure doses and the eight potentially completed exposure pathways, the Leviathan Mine Site is considered a public health hazard.
- CDHS recommends that community members, residents, visitors, Washoe Tribal members, and on-site workers avoid contact with Leviathan Mine tailings, surface waters, and sediments from the mine excavation, Leviathan and Aspen creeks and that users of the area minimize exposure to Bryant Creek and the River Ranch Irrigation Channel waters and sediment, until data indicate exposures to these media do not represent a health risk.
- CDHS recommends community members, residents, visitors, and Washoe Tribal members avoid eating fish caught in Leviathan, Aspen, and Bryant creeks and the River Ranch Irrigation Channel until it can be determined if fish in these areas contain elevated levels of metals associated with AMD contamination that could present health risks.
- CDHS recommends that people who collect plants in the vicinity of Leviathan Mine for consumptive or other purposes select harvest locations as far from the mine site as possible. CDHS also recommends that these plants be washed with non-contaminated water to remove dust and dirt from the plants. These efforts will help minimize potential risks from consuming or using plants from the area.
- CDHS recommends that EPA or other appropriate agency collect fish tissue data for the creeks downstream of Leviathan Mine to determine if fish in the area have concentrations of AMD contaminants at levels that could present health risks.
- CDHS recommends that EPA or LRWQCB assess the characteristics of the roadbed materials on roads that access Leviathan Mine to determine if AMD contaminants are a present in the roadbed at concentrations that could present a health risk.
- CDHS recommends that EPA or LRWQCB collect sediment data from creek beds to better understand the potential risks these sediments pose.
- CDHS recommends that future surface water sampling events include total and dissolved analyses.
- CDHS recommends that EPA, LRWQCB and ARC assure that dust minimization efforts are undertaken at the site during remedial operations to reduce any potential future AMD-contaminated dust exposures.
- If AMD contaminants from Leviathan Mine are found to be accumulating in fish collected from the impacted creeks, CDHS recommends that EPA or LRWQCB investigate other wildlife for the potential to be accumulating contaminants from Leviathan Mine.
- CDHS recommends that EPA or LRWQCB conduct surface water and sediment sampling at River Ranch to determine if AMD contaminants are present in water used on the ranch for agricultural and livestock purposes.
The Public Health Action Plan (PHAP) for this site contains a description of actions under consideration by ATSDR and CDHS at and near the site. The purpose of the PHAP is to ensure that this health assessment not only identifies public health hazards, but also provides a plan of action designed to mitigate and prevent adverse human health effects resulting from exposure to hazardous substances in the environment. CDHS and ATSDR will follow up on this plan to ensure that actions are carried out.
Past Actions Conducted by CDHS at the Leviathan Mine Site
October 2000: CDHS releases Initial Draft Public Health Assessment.
July 2001: CDHS visited the Leviathan Mine Site and remedial works to better understand processes and potential exposures.
August 2001: CDHS meets with Washoe Tribe, USEPA, Carson Water Subconservancy District, LRWQCB and USGS to discuss remedial options and understand their perspectives on the site.
Fall 2001: CDHS made follow up attempts (via phone) to discuss with the Washoe Tribe how they use the area near the mine. However, information about use in the area is very limited mainly because the Washoe Tribe is reluctant to provide details about their cultural behaviors.
May 2002: CDHS releases Public Comment Draft of the Leviathan Mine Site. Open comment period originally set from May 4 to June 18, 2002. Public notices about the availability of the PHA were placed in three print and online newspapers.
May 2002: CDHS held a public meeting in Dresslerville, NV. Notices were sent to over 1,200 individuals in the area, mostly Washoe tribal members. There was some concern expressed during this meeting that the public comment period for the PHA was not long enough. In response, CDHS extended the deadline for two additional weeks.
December 2002: CDHS met with the Washoe Tribe, USGS, USEPA, Bureau of Indian Affairs and the National Forest Service to discuss posting efforts in areas near Leviathan Mine
If subsequent data collected at Leviathan Mine and associated creeks indicate re-evaluation of the estimated risks is needed, CDHS will evaluate that data.
CDHS will meet with community members to communicate the findings of this public health assessment. Specific goals should be to increase the understanding of the technical aspects of the area contaminants and their fate and transport, and to educate the community about potential health impacts of exposure to site contaminants.
CDHS intends to work with stakeholders to provide warning postings for potential users of areas near the mine to inform visitors of the potential risks and how to avoid them.
CDHS intends to work with stakeholders and other interested parties to determine appropriate educational and outreach materials for the Leviathan Mine Site.
Environmental Health Effects Assessors
Gregory E. Braun
Research Scientist
Impact Assessment Inc.
Consultant to Environmental Health Investigations Branch
California Department of Health Services
Marilyn C. Underwood, PhD
Staff Toxicologist
Environmental Health Investigations Branch
California Department of Health Services
Community Involvement Coordinator/Health Educator
Jay LaPlante
Community Health Educator
Environmental Health Investigations Branch
California Department of Health Services
ATSDR Regional Representatives
William Q. Nelson
Libby Levy
Regional Representatives, Region IX
Agency for Toxic Substances and Disease Registry
ATSDR Technical Project Officer
Tammie McRae, MS
Environmental Health Scientist
Agency for Toxic Substances and Disease Registry
This Public Health Assessment, Leviathan Mine Site, Alpine County, California, was prepared by the California Department of Health Services under a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR). It is in accordance with approved methodology and procedures existing at the time the public health assessment was begun.
Tammie McRae, MS
Technical Project Officer, SPS, SSAB, DHAC
The Division of Health Assessment and Consultation, ATSDR, has reviewed this public health assessment and concurs with the findings.
Sven E. Rodenbeck
for Roberta Erlwein
Chief, State Program Section, DHAC, ATSDR
- California Regional Water Quality Control Board--Lahontan Region. Leviathan Mine 5-year workplan. South Lake Tahoe, California: Lahontan Regional Water Quality Control Board; 1995 Jul.
- California Regional Water Quality Control Board--Lahontan Region. Report on pollution of Leviathan Creek, Bryant Creek, and the East Fork Carson River caused by the Leviathan Sulphur Mine. South Lake Tahoe, California: Lahontan Regional Water Quality Control Board; 1975 Jan.
- California Department of Fish and Game. Leviathan Mine natural resources damage assessment phase I fisheries assessment. Sacramento, California: California Department of Fish and Game; 2000 Oct.
- Thompson L, Welsh D. Assessment of injuries to aquatic natural resources near the Leviathan Mine, Alpine County, California, phase II report: the toxicity and chemistry of receiving streams during evaporation pond overflows and the Leviathan Mine in April 1999. Washington, DC: U.S. Fish and Wildlife Service; January 28, 2000.
- US Department of Agriculture. Review of draft public health assessment, Leviathan Mine. Washington, DC: US Department of Agriculture; 2001 Jul 31.
- Cleanup at Leviathan Mine discussed. The Nevada Appeal News. 1998 Mar 15.
- Hammermeister, Dale P, and Stephen J. Walmsley, "Hydrologic Data for Leviathan Mine and Vicinity, Alpine County, California, 1981-83, U.S. Geological Survey Open File Report 85-160, 1985.
- SRK for ARCO Environmental Remediation, L.L.C. 1998-1999 Data Summary Report Administrative Order on Consent Leviathan Mine Alpine County, California. December 1999.
- Montgomery Watson for ARCO Environmental Remediation, L.L.C. Leviathan Mine Site Draft Site Management Plan. January 2001
- Hammermeister, Dale P, and David Prudic, "Shallow Ground Water Flow in the Vicinity of the Open Pit at Leviathan Mine, U.S. Geological Survey, 1987.
- Herbst, R.B. Sierra Nevada Aquatic Research Laboratory - University of California for U.S. Forest Service. Bioassessment Monitoring of Acid Mine Drainage Impacts in Streams of the Leviathan Mine Watershed for Spring and Fall 1999.
- ENSR for ARCO Environmental Remediation, L.L.C. Data Report for the Leviathan Mine Study Area, Water and Sediment Toxicity Testing and Benthic Community Data: September 1998 Assessment. December 1999.
- Thomas, K.A., Lico, M.S., United States Geological Survey. Open-File Report 00-77. Data on Stream-Water and Bed-Sediment Quality in the Vicinity of Leviathan Mine, Alpine County, California, and Douglas County, Nevada, September 1998.
- Analytical Results from Leviathan Mine Water and Sediment Samples from Dr. Herbst Event. U.S. Environmental Protection Agency. December 2000.
- Lahontan Regional Water Quality Control Board, Site Safety Plan, Leviathan Mine, Alpine County. August 20, 1996.
- Earth Safety Dynamics, Assessment of Arsenic Exposure During Earth Work, July 27, 2001.
- Agency for Toxic Substances and Disease Registry. Public Health Assessment Guidance Manual. U.S. Department of Health and Human Services Public Health Service. 1997.
- Eastern Research Group, Summary Report For The ATSDR Expert Panel Meeting on Tribal Exposures To Environmental Contaminants in Plants. Prepared for ATSDR. March 23, 2001.
- Agency for Toxic Substances and Disease Registry. Toxicological Profile for Cadmium. Prepared by Research Triangle Institute, 1998.
- Agency for Toxic Substances and Disease Registry. Toxicological Profile for Arsenic. Prepared by Research Triangle Institute, 1998.
- Agency for Toxic Substances and Disease Registry. Toxicological Profile for Nickel. Prepared by Research Triangle Institute, 1997.
- Excerpts from Ecological Restoration: A Tool to Manage Stream Quality. http://www.epa.gov/OWOW/NPS/Ecology/chap3.html.
- U.S. Environmental Protection Agency. Exposure Factors Handbook, Office of Research and Development. August 1997.
- U.S. Environmental Protection Agency. Risk Assessment Guidance for Superfund Volume I: Human Health Evaluation Manual (Part E, Supplemental Guidance for Dermal Risk Assessment) Interim, Review Draft-For Public Comment, Office of Emergency and Remedial Response. September 2001.
- Agency for Toxic Substances and Disease Registry. Toxicological Profile for Aluminum. Prepared by Research Triangle Institute, 1997.
- Agency for Toxic Substances and Disease Registry. Toxicological Profile for Manganese. Prepared by Research Triangle Institute, 1997.
- Agency for Toxic Substances and Disease Registry. Toxicological Profile for Thallium. Prepared by Clement International Corporation, 1992.
- California Department of Health Services, Water Quality Monitoring Database, as provided in Site Report for Leviathan Mine, produced by U.S. Environmental Protection Agency Region 9, GIS Center, September 9, 1997.
- U.S. Environmental Protection Agency. Risk Assessment Guidance for Superfund, Volume I Human Health Evaluation Manual (Part A). December 1989.
- Lawrence, Stephen J., United States Geological Survey. Water Resources Investigations Report 97-4258, Trace-Element Enrichment in Streambed Sediment and Crayfish in the Carson and Truckee River Basins in Nevada and California, 1998.
- Thompson, L. & Welsh, D., U.S. Fish and Wildlife Service, Assessment of Injuries to Aquatic Natural Resources near the Leviathan Mine, Alpine County, California. Phase I Data Report: Concentrations of Metals and Trace Elements in Aquatic Insects and Fish. December 1999.
- U.S. Environmental Protection Agency. Exposure Factors Handbook, Office of Research and Development. August 1997.
- U.S. Environmental Protection Agency. Risk Assessment Guidance for Superfund, Volume I Human Health Evaluation Manual (Part E, Supplemental Guidance for Dermal Risk Assessment) Interim. September 2001.
- California Regional Water Quality Control Board - Lahontan Region. Provisional Water Quality Data for the Leviathan/Bryant Creek Watershed, December 1999.
- U.S. Environmental Protection Agency. Washington, D.C. National Priorities List (NPL) Fact Sheet on Leviathan Mine, November 1999.
Table 1. Surface Water Data Collected from 1968-1969 Near Leviathan Mine (ug/L:ppb)
| Near Mine Discharge | Leviathan Creek | River Ranch Irrigation Channel | Health Comparison Values | ||||||||
| 12/5/68 | 6/12/69 | 9/22/69 | 12/5/68 | 6/12/69 | 9/22/69 | 12/5/68 | 6/12/69 | 9/22/69 | Child | Adult | |
| Arsenic | 20 - 70000 | 520 - 110000 | 100 - 63500 | NA | 1200 | 760 | 90 | 100 | 200 | 3-chronic EMEG | 10-chronic EMEG |
| Manganese | 4800 - 7900 | <500 - 2900 | 4500 - 8200 | 4000 | ND | 13000 | 100 | ND | 610 | 500-RMEG | 2000-RMEG |
Notes
MCL for Aluminum = 1000 ppb
MCL for Arsenic = 10 ppb
Secondary MCL for Manganese = 50 ppb
NA- not analyzed
ND - Not detected
EMEG-Environmental Media Evaluation Guideline
RMEG-Risk Media Evaluation Guideline
Data originally presented in California Regional Water Quality Control Board
- Lahontan Region. Report on Pollution of Leviathan Creek, Bryant Creek and
the East Fork Carson River caused by the Leviathan Sulphur Mine. January 1975.
Cadmium and Nickel data was not provided in this report.
Table 2. Summary of Average Dissolved Metals
in Surface Waters Collected Near Leviathan Mine Between 1981 and 1983 (ug/L:
ppb)
| Site 2: Leviathan Mine | Site 10: Leviathan Creek | Site 16: Aspen Creek | Site 25: Bryant Creek | Site 26: River Ranch Irrigation Channel | Child Health Comparison Values | Adult Health Comparison Values | |
| Arsenic | 18001* | 970 | 10 | 100 | 50.2 | 3 chronic EMEG | 10 chronic EMEG |
| Cadmium | 154.2 | 18.6 | ND | 5.33 | 3 | 2 chronic EMEG | 7 chronic EMEG |
| Manganese | 8962 | 8600 | 1267 | 820 | 856.6 | 500 RMEG | 2000 RMEG |
| Nickel | 8550 | 1960 | 100 | 325 | 275 | 200 RMEG | 700 RMEG |
Data presented in USGS Open File Report 85-160: Hydrologic
Data for Leviathan Mine and Vicinity, Alpine County, California, 1981-1983.
EMEG-Environmental Media Evaluation Guideline
RMEG-Risk Media Evaluation Guideline
| Site 2 | Seep at Leviathan Mine Tunnel #5 |
| Site 10 | Leviathan Creek below inflow from pit and tunnel |
| Site 16 | Aspen Creek above Leviathan Creek |
| Site 25 | Bryant Creek below confluence of Leviathan & Mountaineer Creeks |
| Site 26 | Bryant Creek above Doud Creek |
* Two samples collected between 1982 & 1983 had detections
of 30,000 ppb arsenic.
ND - Not Detected
Table 3. Average Dissolved Surface Water
Data From Leviathan Mine Collected Between 1995 and 2001 (ug/l: ppb)
| Sample Location | Arsenic | Cadmium | Manganese | Nickel |
| Station 2: Adit at Leviathan Mine | 14000 | 37 | 6700 | 5600 |
| Station 15 - Leviathan Creek a short distance upstream of confluence with Aspen | 198 | 2 | 4840 | 561 |
| Station 16- Aspen Creek a short distance upstream of its confluence with Leviathan | 12 | 2.8 | 6551 | 36 |
| Station 25-Bryant Creek a short distance downstream of Leviathan and Mountaineer | 11.8 | 2.7 | 5606 | 84.6 |
| Station 26-Bryant Creek upstream of Doud Creek | 5 | NA | 42 | 105.4 |
| Health Comparison Value | 3 - Child Chronic EMEG | 2 - Child Chronic EMEG | 500 - Child RMEG | 200 - Child RMEG |
This data was collected by the LRWQCB between 1995 and 2001.
The number of samples collected for each analyte at each location
varies considerably from one sample for manganese at Station 26 to 108 samples
for arsenic at Station 25.
EMEG-Environmental Media Evaluation Guideline
RMEG-Risk Media Evaluation Guideline
Table 4. Summary of Sediment Data Collected
Near Leviathan Mine on May 12, 1983 (mg/kg: ppm)
| Site 17: Leviathan Creek Below Aspen Creek | Site 25: Bryant Creek below confluence of Leviathan and Mountaineer Creeks | Site 26: Bryant Creek above Doud Creek | Child Health Comparison Values (soil) | Adult Health Comparison Values (soil) | |
| Aluminium | 560000 | 590000 | 52000 | 100000-interm. EMEG | 1000000-interm. EMEG |
| Arsenic | 280 | 170 | 250 | 20-chronic EMEG | 200-chronic EMEG |
| Cadmium | ND | ND | 1 | 10-chronic EMEG | 100-chronic EMEG |
| Nickel | 30 | 10 | 10 | 1000-RMEG | 10000-RMEG |
This data represent the concentrations presented in the USGS
Open File 85-160.
No manganese data was reported for these samples.
EMEG-Environmental Media Evaluation Guideline
RMEG-Risk Media Evaluation Guideline
Table 5. Sediment Data Collected From Creeks
Near Leviathan Mine in September 1998 by USGS (mg/kg: ppm)
| Approximate Sample Location | Station Number | Aluminum | Arsenic | Cadmium | Manganese | Nickel | |||||
| Average | Average | Average | Average | Average | |||||||
| Leviathan Creek | #11 | 15000 | 560 | ND | 160 | 10 | |||||
| 7300 | 10533 | 600 | 613 | ND | - | 73 | 106 | 5 | 7 | ||
| 9300 | 680 | ND | 86 | 6 | |||||||
| Aspen Creek | #12 | 90000 | 43 | 0.2 | 930 | 40 | |||||
| 100000 | 95000 | 55 | 47 | 0.2 | 0.2 | 1100 | 1043 | 43 | 42 | ||
| 95000 | 43 | 0.3 | 1100 | 42 | |||||||
| Bryant Creek | #8 | 80000 | 99 | 1.2 | 250 | 250 | |||||
| 79000 | 80333 | 110 | 113 | 1.4 | 1.2 | 190 | 217 | 190 | 217 | ||
| 82000 | 130 | 0.9 | 210 | 210 | |||||||
| River Ranch Irrigation Channel | #6 | 84000 | 130 | 1.7 | 320 | 320 | |||||
| 86000 | 85667 | 140 | 140 | 1.7 | 1.7 | 330 | 327 | 330 | 327 | ||
| 87000 | 150 | 1.7 | 330 | 330 | |||||||
| Child Health Comparison Value (soil) | 100000 int. EMEG | 20 chronic EMEG | 10 chronic EMEG | 3000 RMEG | 1000 RMEG | ||||||
| Adult Health Comparison Value (soil) | 1000000 int. EMEG | 200 chronic EMEG | 100 chronic EMEG | 40000 RMEG | 10000 RMEG | ||||||
Samples were collected between September 22 and September 28,
1998.
Data from: Data on Stream-Water and Bed-Sediment Quality in the Vicinity of
Leviathan Mine, Alpine County, California, and Douglas County, Nevada, Sept.
1998 by U.S. Fish & Wildlife Service (Open-File Report 00-77).
ND- Not Detected
EMEG-Environmental Media Evaluation Guideline
RMEG-Risk Media Evaluation Guideline
Table 6. Summary of Completed Exposure Pathways
at the Leviathan Mine
| Name | Source | Media | Exposure Point | Exposure Route | Receptor | Time |
| Swimming and wading | AMD from Leviathan Mine | Surface water and sediment | Leviathan Creek Aspen Creek Bryant Creek River Ranch Irrigation Channel |
Dermal and ingestion | Washoe Tribe members and recreational users | Past, present, and future (except Bryant and River Ranch) |
| Drinking | AMD from Leviathan Mine | Surface water | Leviathan Creek Aspen Creek Bryant Creek River Ranch Irrigation Channel |
Ingestion | Washoe Tribe members and recreational users | Past, present, and future (except Bryant and River Ranch) |
Table 7. Summary of Potential Exposure Pathways
at the Leviathan Mine
| Name | Source | Media | Exposure Point | Exposure Route | Receptor | Time |
| Plant consumption or use | AMD from Leviathan Mine | Edible plants growing near Leviathan Mine |
Areas near mine site | Ingestion | Washoe Tribe members and recreational users | Past, present, and future |
| Fish consumption | AMD from Leviathan Mine | Fish | Fish contaminated by Leviathan Mine AMD | Ingestion | Washoe Tribe members and recreational users who eat the fish | Past, present, and future |
| Wild game and fowl consumption | AMD from Leviathan Mine | Wild game and fowl | Meat from wild game and fowl contaminated by Leviathan Mine AMD | Ingestion | Washoe Tribe members and recreational users eating the meat | Past, present, and future |
| Beef consumption | AMD from Leviathan Mine | Beef | Meat from cattle raised on the River Ranch that were exposed to AMD-contaminated feed/water | Ingestion | Beef eaters | Past, present, and future |
| Drinking | AMD from Leviathan Mine | Surface water | Bryant Creek & River Ranch Irrigation Channel |
Ingestion | Washoe Tribe members and recreational users | Future |
| Swimming and wading | AMD from Leviathan Mine | Surface water & Sediment | Bryant Creek & River Ranch Irrigation Channel |
Dermal and ingestion | Washoe Tribe members and recreational users | Future |
| Dust inhalation | AMD dust from Leviathan Mine | Air/Dust | Areas impacted by AMD from Leviathan Mine | Inhalation | Washoe Tribe members and recreational users | Past, present, and future |
| Groundwater consumption | AMD from Leviathan Mine | Groundwater | Private wells | Ingestion, inhalation & absorption | Private well users | Future |
Table 8. Summary of Exposure Dose Estimates
for Completed Pathways to Adults
| NON-CANCER DOSE (mg/kg/day) | CANCER RISK | |||||||||||||
| SWIMMING | WADING | wade & swim | DRINKING | DRINKING | SWIMMING | WADING | wade & swim | DRINKING | TOTAL | |||||
| Arsenic | Cd | Mn | Nickel | Arsenic | Mn | Arsenic | ||||||||
| Leviathan Creek | Past | 2.85E-05 | * | 2.29E-04 | * | 6.90E-06 | 3.54E-05 | 1.78E-03 | 1.58E-02 | 9.11E-05 | 9.80E-06 | 1.01E-04 | 1.13E-03 | 1.23E-03 |
| Present | 5.26E-06 | 5.32E-08 | 1.29E-04 | 7.45E-04 | 2.30E-06 | 7.56E-06 | 3.64E-04 | 8.90E-03 | 1.86E-05 | 2.40E-06 | 2.10E-05 | 2.32E-04 | 2.53E-04 | |
| Aspen Creek | Past | 2.66E-07 | * | 3.37E-05 | * | 1.50E-07 | 4.16E-07 | 1.84E-05 | 2.33E-03 | 9.40E-07 | 1.40E-07 | 1.08E-06 | 1.17E-05 | 1.28E-05 |
| Present | 3.19E-07 | 7.44E-08 | 1.74E-04 | 4.78E-05 | 1.60E-07 | 4.79E-07 | 2.21E-05 | 1.20E-02 | 1.13E-06 | 1.60E-07 | 1.29E-06 | 1.40E-05 | 1.53E-05 | |
| Bryant Creek | Past | 2.66E-06 | * | 2.18E-05 | * | 8.80E-07 | 3.54E-06 | 1.84E-04 | 1.51E-03 | 9.40E-06 | 1.00E-06 | 1.04E-05 | 1.17E-04 | 1.27E-04 |
| Present | 3.14E-07 | 7.18E-08 | 1.49E-04 | 1.12E-04 | 3.00E-07 | 6.14E-07 | 2.17E-05 | 1.03E-02 | 1.11E-06 | 2.40E-07 | 1.35E-06 | 1.38E-05 | 1.52E-05 | |
| River Ranch Irrigation Channel |
Past | 1.41E-06 | * | 2.27E-05 | * | 1.60E-06 | 3.01E-06 | 9.19E-05 | 1.57E-03 | 4.98E-06 | 1.90E-06 | 6.88E-06 | 5.85E-05 | 6.54E-05 |
| Present | 1.33E-07 | 7.18E-08 | 1.12E-06 | 1.40E-04 | 3.20E-07 | 4.53E-07 | 9.19E-06 | 7.72E-05 | 4.70E-07 | 2.20E-07 | 6.90E-07 | 5.85E-06 | 6.54E-06 | |
| MRL or RfD | 3.00E-04 | 2.00E-04 | 5.00E-03 | 2.00E-02 | 3.00E-04 | 6.00E-04 | 3.00E-04 | 5.00E-03 | ||||||
*Past exposure to cadmium and nickel were not assessed due
to insufficient data.
Minimal Risk Level (MRL) listed for arsenic is the chronic MRL. The acute MRL
for arsenic is 0.005 mg/kg/day.
Bolded numbers exceed MRL, Reference Dose (RfD) or are carcinogenic
risks greater than 1.0 E -06 (or greater than 1 in 1,000,000 additional risk).
Mn-Manganese
Cd-Cadmium
Table 9. Summary of Exposure Dose Estimates
for Completed Pathways to Children
| NON-CANCER DOSE (mg/kg/day) | CANCER RISK | |||||||||||||
| SWIMMING | WADING | wade & swim | DRINKING | DRINKING | SWIMMING | WADING | wade & swim | DRINKING | TOTAL | |||||
| Arsenic | Cd | Mn | Nickel | Arsenic | Mn | Arsenic | ||||||||
| Leviathan Creek | Past | 6.00E-05 | * | 5.32E-04 | * | 4.20E-05 | 1.02E-04 | 2.39E-03 | 2.12E-02 | 2.12E-04 | 3.40E-05 | 2.46E-04 | 1.52E-03 | 1.77E-03 |
| Present | 1.23E-05 | 1.24E-07 | 3.00E-04 | 1.74E-03 | 7.40E-05 | 8.63E-05 | 4.88E-04 | 1.19E-02 | 4.33E-05 | 4.80E-05 | 9.13E-05 | 2.32E-04 | 3.10E-04 | |
| Aspen Creek | Past | 2.66E-07 | * | 7.84E-05 | * | 5.70E-06 | 5.97E-06 | 2.46E-05 | 2.33E-03 | 2.19E-06 | 3.70E-06 | 5.89E-06 | 1.57E-05 | 2.16E-05 |
| Present | 7.43E-07 | 1.73E-07 | 4.06E-04 | 1.11E-04 | 5.70E-06 | 6.44E-06 | 2.96E-05 | 1.61E-02 | 2.63E-06 | 3.70E-06 | 6.33E-06 | 1.40E-05 | 1.88E-05 | |
| Bryant Creek | Past | 2.66E-06 | * | 5.08E-05 | * | 2.10E-05 | 2.37E-05 | 2.46E-04 | 1.51E-03 | 2.19E-05 | 1.40E-05 | 3.59E-05 | 1.57E-04 | 1.93E-04 |
| Present | 7.30E-07 | 1.67E-07 | 3.47E-04 | 2.62E-04 | 1.40E-05 | 1.47E-05 | 2.91E-05 | 1.38E-02 | 2.58E-06 | 8.70E-06 | 1.13E-05 | 1.38E-05 | 1.85E-05 | |
| River Ranch Irrigation Channel | Past | 1.41E-06 | * | 5.30E-05 | * | 3.10E-05 | 3.24E-05 | 1.23E-04 | 1.57E-03 | 1.16E-05 | 2.10E-05 | 3.26E-05 | 7.84E-05 | 1.11E-04 |
| Present | 3.10E-07 | 1.67E-07 | 2.60E-06 | 3.26E-04 | 1.70E-05 | 1.73E-05 | 1.23E-05 | 1.03E-04 | 1.09E-06 | 1.10E-05 | 1.21E-05 | 5.85E-06 | 7.84E-06 | |
| MRL or RfD | 3.00E-04 | 2.00E-04 | 5.00E-03 | 2.00E-02 | 3.00E-04 | 6.00E-04 | 3.00E-04 | 5.00E-03 | ||||||
*Past exposure to cadmium and nickel were not assessed due
to insufficient data.
Minimal Risk Level (MRL) listed for arsenic is the chronic MRL. The acute MRL
for arsenic is 0.005 mg/kg/day.
Bolded numbers exceed MRL, Reference Dose (RfD) or are carcinogenic
risks greater than 1.0 E -06 (or greater than 1 in 1,000,000 additional risk).
Mn-Manganese
Cd-Cadmium
Table 10. Exposure Parameters Chosen for
Evaluating Exposure Pathways
| Exposure Parameter | Receptor | |
| Children | Adults | |
| Mean body weight | 26.78 kg (6-9 year olds) | 71.8 kg |
| Skin surface area* | ||
| Swimming (entire body) | 9,250 cm2 | 18,150 cm2 |
| Wading--water | 2,904 cm2 | 5,704 cm2 |
| Wading--sediment | 2,294 cm2 | 4,498 cm2 |
| Exposure duration | ||
| Swimming | 1 hr/day | 1 hr/day |
| Wading | 1 hr/day | 1 hr/day |
| Daily drinking water intake | 2.00 L/day | 1.00 L/day |
| Incidental ingestion while swimming | 0.05 L/hr | 0.05 L/hr |
| Dermal absorption factor--arsenic | 0.001 | 0.001 |
| Dermal absorption factor--cadmium | 0.001 | 0.001 |
| Dermal absorption factor--manganese | 0.001 | 0.001 |
| Dermal absorption factor--nickel | 0.001 | 0.001 |
| Default permeability of water | 8.4 E-4 cm/hr. | 8.4 E-4 cm/hr |
| Permeability constant--arsenic | 0.001 cm/hr | 0.001 cm/hr |
| Sediment adherence factor | 21 mg/cm2 | 0.5 mg/cm2 |
*Adult surface area (S.A.) uses the 50th percentile
for total body surface area for adults
*Child S.A. uses the 50th percentile for total body surface area
for children aged 6 through 9
Used the geometric mean for "children in mud" (21 mg/cm2) and the 95th percentile for "gardeners" for adults (0.5 mg/cm2) per the EPA Interim Risk Assessment Guidance for Superfund, Vol. I (24).
Wading calculations used the 50th percentile values for adult lower leg, feet, and hands for sediment calculations (5,704 cm2). The wading surface area value for water exposure also included the surface area of the head in consideration of traditional washing practices when Washoe Tribal Members hunt and gather in the area.
Because there are no standard surface area values for body portions for children, CDHS used a relative percentage of the total surface area to the lower extremity surface area to estimate child lower extremity surface areas. The adult ratio of total surface area to wading-water area is approximately 31.4%. Therefore, 31.4% of the child 50th percentile total surface area (9,250 cm2 x 0.314 = 2,904 cm2) is used as an estimate of the child wading surface area. For the sediment surface area estimates the same approach was used.
Figure 1. GIS Topographic Map of the Leviathan Mine Site and Vicinity
Figure 2. 1999 Surface Water Sampling Locations at Leviathan Mine and Associated Watershed
Figure 3. Narrative Description of Surface Water Sampling Locations presented in U.S. Fish and Wildlife Service, Assessment of Injuries to Aquatic Natural Resources near the Leviathan Mine, Alpine County, California (3).
Station 1: Aspen Creek, upstream of releases from the Leviathan Mine.
Station 3: Leviathan Creek, a short distance upstream of its confluence with Aspen Creek.
Station 4: Aspen Creek, a short distance upstream of its confluence with Leviathan Creek.
Station 17: Leviathan Creek, a short distance downstream of its confluence with Aspen Creek.
Station 5: Leviathan Creek, a short distance upstream of its confluence with Mountaineer Creek
Station 6: Mountaineer Creek, a short distance upstream of its confluence with Leviathan Creek.
Station 7: Bryant Creek, a short distance downstream of the confluence of Leviathan and Mountaineer creeks.
Station 9: Bryant Creek, a short distance upstream of Doud Springs Creek.
Station 10 : Bryant Creek, a short distance upstream of its confluence with the East Fork of the Carson River.
Station 11: East Fork Carson River, a short distance upstream of Bryant Creek.
Station 12: East Fork Carson River, a short distance downstream of Bryant Creek.
Station 13: East Fork Carson River, a short distance upstream of Ruhenstroth Dam.
APPENDIX C: TOXICOLOGICAL SUMMARIES FOR CHEMICALS FOUND NEAR LEVIATHAN MINE
Metals
Aluminum (25)
- Aluminum is a naturally occurring substance found in many types of rock.
- In acidic soils aluminum becomes more mobile.
- Concentrations of aluminum in natural waters and drinking waters is generally below 0.1 ppm.
- People may get skin rashes from aluminum products.
- Large amounts of aluminum have been shown to be harmful to unborn and developing animals.
- Aluminum has not been shown to cause cancer in animals.
- EPA has a secondary MCL of 0.05 ppm for aluminum in drinking water.
- Aluminum can be found in consumer products such as cookware, utensils, aluminum foil, antacids, antiperspirants and in some foods.
- ATSDR has established an Intermediate oral MRL of 2 mg/kg/day for aluminum.
- ATSDR has established an Intermediate EMEG of 20,000 ppb in water for children and 70,000 ppb in water for adults.
Arsenic (20)
- Arsenic is found in nature at low levels.
- It is mostly in compounds with oxygen, chlorine, and sulfur; these are called inorganic arsenic compounds.
- Arsenic in plants and animals combines with carbon and hydrogen; this is called organic arsenic. Organic arsenic is usually less harmful than inorganic arsenic.
- In the environment, arsenic does not evaporate. Most arsenic compounds can dissolve in water. Arsenic can get into air when contaminated materials are burned; however, it settles from the air to the ground. In the ground, it does not break down, but it can change from one form to another. Fish and shellfish build up organic arsenic in their tissues, but most of the arsenic in fish is not toxic.
- You can be exposed to arsenic by breathing sawdust or burning smoke from wood containing arsenic; breathing workplace air; ingesting contaminated water, soil, or air at waste sites containing arsenic; or ingesting contaminated water, soil, or air near areas naturally high in arsenic.
- Lower levels of exposure to inorganic arsenic might cause: nausea, vomiting, and diarrhea; decreased production of red and white blood cells; abnormal heart rhythm; blood vessel damage; and/or a "pins and needles" sensation in hands and feet.
- Arsenic is genotoxic. Arsenic compounds inhibit DNA repair and induce chromosome aberrations and sister chromatid exchanges. Recent evidence suggests that inorganic arsenic induces gene amplifications in mammalian cells which could affect later stages of the carcinogenesis process.
- High levels of inorganic arsenic in food or water can be fatal. A high level is 60 parts of arsenic per million parts of food or water (60 ppm). Arsenic damages many tissues including nerves, stomach and intestines, and skin. Breathing high levels can cause a sore throat and irritated lungs.
- Long-term exposure to inorganic arsenic might lead to a darkening of the skin and the appearance of small "corns" or "warts" on the palms, soles, and torso.
- ATSDR's chronic oral MRL = 0.0003 mg/kg/day (critical endpoints: hyperpigmentation, keratosis, and possible vascular complications in humans).
- ATSDR's acute oral MRL = 0.005 mg/kg/day (critical endpoints: gastronomic complications).
- The Department of Health and Human Services (DHHS) has determined that arsenic is a known carcinogen. Breathing inorganic arsenic increases the risk of lung cancer. Ingesting inorganic arsenic increases the risk of skin cancer and tumors of the bladder, kidney, liver, and lung.
Cadmium (19)
- Cadmium is an element that occurs naturally in the earth's crust.
- Cadmium has no recognizable smell or taste.
- Cadmium is used in industry in consumer products such as batteries, pigments, metal coatings, plastics, and some metal alloys.
- Small amounts of cadmium enter the environment from natural erosional forces, forest fires, or volcanoes, but most of the cadmium that enters the environment comes from human activities.
- Fish, plants, and animals can take cadmium into their bodies from air, water, or food. Cadmium stays in the body for a very long time (years).
- Breathing air with high concentrations of cadmium severely damages the lungs and can cause death.
- Breathing low levels of cadmium for years leads to a buildup of cadmium in the kidneys that can cause kidney disease.
- HHS has determined that cadmium might reasonably be anticipated to be a carcinogen.
- The International Agency for Research on Cancer (IARC) has determined that cadmium is carcinogenic to humans.
- EPA has determined that cadmium is a probable human carcinogen by inhalation.
- EPA allows up to 5 ppb of cadmium in drinking water.
- Inhalation of high levels of cadmium oxide fumes or dust is intensely irritating to respiratory tissue.
- Acute, high-level exposures can be fatal and those who survive might have impaired lung function for years after a single acute exposure.
- ATSDR's chronic oral MRL = 0.0002 mg/kg/day, based on renal effects in humans.
Manganese (26)
- Manganese is a naturally occurring substance found in many types of rock.
- Manganese has no recognizable smell or taste.
- Manganese is an essential nutrient and eating small amounts each day is important to stay healthy.
- Studies in animals have shown that high levels of manganese in food or water can cause changes in the brain.
- Breathing manganese dust can cause irritation of the lungs.
- There is limited information about manganese effects on birth defects.
- Exposure to high concentrations of manganese via inhalation can lead to a disabling neurological syndrome called manganism. This condition manifests in symptoms similar to Parkinson's Disease.
- Manganese is a metal that is mixed with iron to make various types of steel. Manganese can be found in consumer products such as batteries, ceramics, pesticides, and fertilizers.
- EPA has derived a chronic oral RfD of 0.005 mg manganese/kg/day in water and 0.14 mg/kg/day for manganese in food.
- EPA also has derived a chronic inhalation RfC of 0.00005 mg/m3 for manganese.
- EPA has determined that manganese is not classifiable as a human carcinogen.
- To avoid staining of clothes, EPA allows up to 50 ppb of manganese in drinking water.
- ATSDR's chronic inhalation MRL= 0.00004 mg manganese/m3. No oral MRLs have been derived for manganese.
Nickel (21)
- Pure nickel is a hard, silvery-white metal with properties that make it very desirable for combining with other metals to form mixtures called alloys. Nickel combined with other elements occurs naturally in the earth's crust. It is found in all soil and is also emitted from volcanos.
- Nickel might be released to the environment from the stacks of large furnaces used to make alloys or from power plants and trash incinerators. The nickel that comes out of the stacks of power plants is attached to small particles of dust that settle to the ground or are taken out of the air in rain.
- People might be exposed to nickel by breathing air, drinking water, eating food, or smoking tobacco containing nickel. Skin contact with soil, water, or metals containing nickel can also result in exposure.
- The most common adverse health effect of nickel in humans is an allergic reaction to nickel. People can become sensitive to nickel when jewelry or other things containing nickel are in direct contact with the skin. Once a person is sensitized to nickel, further contact with the metal will produce a reaction. The most common reaction is a skin rash at the site of contact. People who are not sensitive to nickel must eat very large amounts of nickel to suffer adverse health effects.
- The most serious effects of nickel, such as cancer of the lung and nasal sinus, have occurred in people who have breathed dust containing nickel compounds while working in nickel refineries or in nickel-processing plants. Other lung effects including chronic bronchitis and reduced lung function have been observed in workers breathing nickel. Current levels of nickel in workplace air are much lower than in the past, and few workers have symptoms from nickel exposure.
- EPA's chronic oral RfD = 0.02 mg/kg/day (critical endpoint: decreased body and organ weights in rats).
- ATSDR's chronic inhalation MRL = 0.0002 mg/m3 (critical endpoints: respiratory complications).
- The Department of Health and Human Services has determined that nickel and certain nickel compounds might reasonably be anticipated to be carcinogens. The IARC has determined that some nickel compounds are carcinogenic to humans and that metallic nickel might possibly be carcinogenic to humans. EPA has determined that nickel refinery dust and nickel sulfide are human carcinogens.
Thallium (27)
- Thallium is a naturally occurring substance found in many types of rock.
- Thallium has no recognizable smell or taste.
- Thallium is used in the manufacture of electrical equipment such as semiconductors.
- The Occupational Safety and Health Administration's (OSHA) permissible exposure limit (PEL) for thallium is 0.1 mg/m.3
- Human occupational studies indicate that thallium exposure might affect the nervous system.
- Short-term exposure to thallium can cause gastrointestinal irritation and nerve damage.
- Long-term exposure to thallium can cause changes in blood chemistry; damage to the liver, kidney, intestinal, and testicular tissues; and hair loss.
- EPA has set the MCL for thallium at 2.0 ppb because this is the lowest level to which water systems can reasonably be required to remove this contaminant should it occur in drinking water.
- The MCL Goal (MCL) is set at 0.5 ppb.
- The Department of Health and Human Services, the International Agency for Research on Cancer, and the Environmental Protection Agency (EPA) have not classified thallium as to its human carcinogenicity.
The California Department of Health Services (CDHS) received comments from the Northern California and Nevada Council of the Federation of Fly Fishers (NCCFFF) in a letter dated June 3, 2002. The NCCFFF had the following general comments pertaining to the April 25, 2002 Public Comment Draft of the Leviathan Mine PHA.
1.NCCFFF commented that the report needs to broaden the review of information to include impacts on the East Fork of the Carson River and on the fisheries in these areas.
Response: Although CDHS understands the concerns of the NCCFFF regarding inclusion of the East Fork of the Carson River in the assessment process, this is beyond the scope of this public health assessment.
2. The report does not reference fish samples collected in the East Fork of the Carson River.
Response: see response #1.
3. The report makes no recommendation about whether it is safe to eat fish caught in the East Fork of the Carson River, nor how far contaminants from Leviathan Mine have migrated down the East Fork of the Carson River.
Response: Because CDHS has not reviewed all the fish sampling data for the East Fork of the Carson River, it would be inappropriate for us to make any such recommendation.
4. Remediation efforts that treat only water quality and do not address contaminants already in the rivers will ultimately be incomplete.
Response: Comment noted.
CDHS received comments from the Washoe Tribe of Nevada and California in a memorandum dated June 18, 2002. The Washoe Tribe had the following comments pertaining to the April 25, 2002 Public Comment Draft of the Leviathan Mine PHA.
1. Pg. 6, 2nd paragraph: Regarding the observation of two fish in the pool, it should be noted that it is unknown how healthy the fish were, how long they had been there, or from where they originated.
Response: Comment noted.
2. Pg. 7, 3rd paragraph: The Superfund Support Agency Cooperative Agreement which the EPA signed with the Washoe Tribe in 1998 has been extended through 2002. A proposal is pending to extend the Agreement through 2003.
Response: Comment noted.
3. Pgs. 11-12: There is not a sufficient basis for determining that the air pathway should be eliminated. Air should be considered as a potential pathway.
Response: Comment noted. In the final PHA, CDHS has included an assessment of potential health risks presented by air at the site in the Environmental Contamination Section. CDHS has recommended further assessment of the roadbed be conducted to determine if mine wastes used on the roadbed could cause exposures to Leviathan Mine contaminants.
4. Pg. 15: The PHA says that MRLs and RfDs for chronic exposures reflect exposures greater than 365 days. How much greater? Do they reflect lifetime exposure? Since the air pathway should not be eliminated, consideration and explanation of RfCs should also be included.
Response: The exposure period used for chronic MRLs includes all exposures greater than one year. The exposure period for chronic RfDs includes exposures that occur for more than 7 years. A brief description of comparison values is included in the Toxicological Evaluation Section
5. Pgs. 17-19: When describing ranges of cancer risks, please use comparable scales. The draft PHA compared, e.g., 7.3 cancer cases out of 100,000 people to 2.4 cases out of 1000 people (PHA, p.17) . Please pick a single scale for all ranges of cancer risks, across all the pathways. Whether the denominator is at the high end (100,000,000), the low end (1,000), or somewhere between, please choose one and convert all the numbers. In addition to the text, a chart would be helpful.
Response: CDHS has made efforts in the Final PHA to use comparable scales for risk.
6. Pg. 20, 2nd paragraph: What do "large amounts" and "high levels" of thallium mean?
Response: Comment noted. This paragraph has been modified to clarify concentrations.
7. Pg. 21: The PHA should recommend additional studies to determine whether any stretch of the East Fork of the Carson River downstream from Bryant Creek represents a public hazard. Plumes of contamination emanating from Bryant Creek were visible in the East Fork as recently as March and April of 1999. Moreover, even without visible contamination plumes, as long as Bryant Creek is contaminated, during those times when the creek flows all the way in to the East Fork, it presumably continues to load contaminants into the East Fork.
This should be considered throughout the PHA, wherever affected waterways are listed. At the very least, the East Fork near the mouth of Bryant Creek should be included in Recommendations 5 and 6.
Response: Comment noted. Although CDHS understands the concerns of the Washoe Tribe regarding inclusion of the East Fork of the Carson River in the assessment process, this is beyond the scope of this public health assessment.
8. Pg. 21, #7: Warning signs should be posted on Forest Service land, Indian allotments, and private lands from the mine all the way down at least to the East Fork just downstream of the mouth of Bryant Creek. CDHS/ATSDR should communicate with the Forrest Service, the BIA and private landowners to get warning signs put up as soon as possible. Such signs are long overdue. Warning signs should be spaced appropriately at all points of potential access to creeks, even at points where access requires hiking in. Regardless, every allotment should have a minimum of 1 sign along the creek. In addition, signs should be posted at the junction of Leviathan Mine Road and U.S. Highway 395, the junction of Leviathan Mine Road and the road leading down to Doud Springs, and the road entering the Leviathan Mine area from the south, and at any other road connected to the Leviathan Mine Road.
Response: CDHS generally agrees that some postings to warn potential users in the area is appropriate. CDHS is in the process of trying to post warning signs in some of these areas with the cooperation of the USEPA, the Bureau of Indian Affairs and the USFS.
9. Pg. 21-22: The following additional recommendations should be included:
(a) Depending on the strictures of air quality monitoring, continuous, or at least regular and frequent, air quality monitoring should be conducted on Leviathan Mine Road, the mine site, and surrounding areas. Meteorologic data should be collected in tandem with air quality monitoring.
(b) Floodplain soils sampling and phytotoxicity testing for riparian vegetation should be conducted.
Response: Comment noted.