SDMS Doc ID 168846 Purpose: CERCLA Site Inspection Site: Mt. Jackson Mercury Mine Sweetwater Springs Road Guerneville, California Sonoma County Investigators: Dick Jones California Janet Naito Department of Health Services Original Investigator; Paul Williams Date of Inspection: February 6, 1989 Report Prepared By: Dick Jones Janet Naito Report Date: August 30, 1989 Assessor's Parcel No: 069-120-07 EPA ID #: CAD980736086 POOR LEGIBILITY ONE OR MORE PAGES IN THIS DOCUMENT ARE DIFFICULT TO READ DUE TO THE QUALITY OF THE ORIGINAL TABLE OF CONTENTS Section Page 1. 0 INTRODUCTION 1 2 . 0 SITE CHARACTERIZATION 2 2 .1 Site History and Description 2 2 .2 Process Description 6 2.3 Waste Management Practices 7 2.4 Permits 7 2.5 Remedial Action 10 3 . 0 ENVIRONMENTAL SETTING 11 3.1 Surrounding Area 11 3.2 Geology 11 3 .3 Surface Water 12 3 .4 Groundwater 13 4 . 0 SUMMARY OF INVESTIGATIVE EFFORTS 18 4.1 Previous Activities By Other Agencies/ Responsible Party 18 4.1.1 Discussion and Evaluation of Previous Sampling/Testing Results 22 4.2 DHS Site Inspection 25 4.2.1 DHS Activities (Summary of Reconnaissance and Site Inspection) 5 . 0 HRS FACTORS 26 6 . 0 RECOMMENDATIONS AND CONCLUSIONS 28 7 . 0 REFERENCES 29 Appendices A Contact Log and Reports B Photo Documentation LIST OF FIGURES AND TABLES Figure Page 1 Site Location Map 3 2 Mount Jackson Mine Facility Map 4 2a Aerial Photograph Mt. Jackson Mine 5 3 Mount Jackson Mine Waste Disposal Plan 8 4 Caputo fie Wagner/Piombo Corp. 9 Facility Map 5 Water Wells Within A 3-Mile Radius 16 6 April 9, 1980 RWQCB Sample Locations 19 and Results Table Page 1 Water Wells Within A Three Mile Radius 14 2 Summary of RWQCB Sampling Results 20 3 Summary of DHS Sampling Results 21 1.0 INTRODUCTION The Site Inspection (SI) of the Mt. Jackson Mercury Mine (MJMM) site was prepared by the California Department of Health Services (DHS) for the U.S. Environmental Protection Agency (EPA) under the CERCLA Grant Program. A Preliminary Assessment (PA) of this site was completed on June 27, 1985 by Ecology and Environment, Inc. (E&E), an EPA Field Investigation Team (FIT) Contractor. This PA was reassessed by E&E on February 4, 1988. E&E recommended further investigation due to the large guantity of tailings remaining on- site, the toxicity of mercury, and the nearby population's use of groundwater as a drinking water source. The site operated intermittently as a mercury mine from approximately 1875 until 1972. From 1979 through 1981, the site was used by a gravel crushing operation. Mercury mine tailings were crushed and the aggregate hauled offsite. The aggregate was used in Sonoma County for road repairs near Ft. Ross and as bedding and backfill material for a sewer line project in Guerneville. Approximately 800,000 tons of mercury mine tailings are still piled on-site. This report summarizes information obtained from the site inspection, the California Department of Health Services (DHS), the North Coast Regional Water Quality Control Board (RWQCB), the California Department of Fish and Game (DFG), the California Occupational Safety and Health Administration (Cal-OSHA), the Sonoma County Environmental Health Department (EHD), the Sonoma County Public Works Department (PWD), and private individuals. This information is the basis for making recommendations for further action regarding the Mt. Jackson Mercury Mine site. The recommendations are based on an analysis of the available information, with a focus on whether the site poses a public health threat and is eligible for inclusion on the National Priorities List (NPL). 2.0 SITE CHARACTERIZATION 2.1 Site History and Description The Mt. Jackson Mercury Mine site (MJMM) is located at 18475 Sweetwater Springs Road, approximately three miles north-northeast of the City of Guerneville in Sonoma County, California.(1,2) (See Figure 1, Site Location Map, Township 8B, Range 10W, Sections 8, 9, 16, 17.) The 410 acre site consists of the Mt. Jackson Mine, the Great Eastern - Roaring Lion Mine, the mill buildings, and tailings piles.(2) (See Figure 2, Site Map and Figure 2a, Aerial Photo.) At some point, the Mt. Jackson and the Great Eastern- Roaring Lion Mines, whose shafts are essentially interconnecting, became known simply as the Mt. Jackson Mine. It appears that they were also referred to as the Sonoma Quicksilver mine.(2) Production at the Mt. Jackson Mine and the Great Eastern-Roaring Lion Mine began about 1875.(3) Originally they operated as two adjacent, but separate mines. From 1888 to 1906, the Mt. Jackson property was leased by the Great Eastern operators.(4) The ore from both mines was hoisted through the Great Eastern shaft and burned in the Great Eastern furnaces. The location of these furnaces is unknown, but are believed to be adjacent to the Great Eastern mineshaft. By 1905, the main Great Eastern shaft had been sunk to a depth of 500 feet and a winze extended 120 feet deeper. Damage caused by the April 18, 1906 earthquake led to the closing of the mines. When they reopened in May 1915, the lower levels were flooded. From 1915 to 1919, mining was carried on only above the hoist level in the Great Eastern mine. Some mining was carried out by several Guerneville townspeople in the Mt. Jackson mine from 1934 to 1939. (4) Sonoma Mines, Inc. (also known as Sonoma, International) gained control of the mine property in 1940. (4) They began to dewater the mines and rebuilt the plant. Production restarted later that year. In May, 1941, the Great Eastern mine was acquired by Magee Mercury, Inc. This mine was dewatered by pumping out the Mt. Jackson Mine. Its main shaft was cleaned out and retimbered to the 500- foot level.(4) Magee Mercury erected the present plant and began production on July 15, 1941. Production in both mines continued until 1971, when both mines became inactive.(4) The site with equipment was then sold to Mr. Walter J. Doyle.(5) In 1979, he sold the site without the equipment to the Piombo Corporation of Windsor, California.(5) The Piombo Corporation acquired MJMM as a source of gravel. Piombo Corporation's subcontractor, Caputo Wagner Company, crushed the mine tailings and hauled out the sorted gravel beginning the summer of 1979 until 1981. (2) The major initial use of the gravel was as bedding and backfill for a sewer line project in Guerneville, California.(2) A quantity of the gravel was hauled to and FIGURE 2 Source: Taken -from June 1980 DHS samp ing report at Mount Jackson Mer ury Mine site. f j, '•A 'v I r*v ^ ^ * *¥. t N\ r • H< • «v»\v So SITE LOCATION MAP , °" . 1 / Mt. Jackson Mercury Mine 1/2 mile r '8* Au/ootu/afror Artrinne Drtarl i > /3?o MILS wwcciwaivJi o|ji iiiyo nuau 0-02' I MIL / Guerneville, CA W I ! Source: USGS Guerneville Quad Map ^vJ Figure 1 ecology and environment, inc. ^ stockpiled along the Seaview Road near Ft. Ross, California for use in road repairs.(1) In 1986, the property was purchased by Mr. Walter J. Doyle.(6) Although he has considered selling the property, Mr. Doyle remains the current owner.(6,7) 2.2 Process Description 2.2.1 Mount Jackson Mercury Mine During the mine's operation, ore was extracted from several levels in the mines, the deepest at about 1450 feet below the ground surface. The ore was crushed at the surface to 1-1/2 inches and finer. (3) The crushed ore was conveyed to the rotary kiln, which was capable of processing about 90 tons of crushed ore in 24 hours.(1,3) Typically, the rotary kilns roasted crushed ore in a stream of air or with lime.(2) This causes the mercuric sulfide (HgS) in the ore to decompose to elemental mercury and hydrogen sulfide or calcium sulfate.(2) It is not known whether air or lime was used at MJMM. The vapors were then drawn off at the upper end of the kiln through a cyclone dust collector. (3) The flow of gases was stimulated by a suction fan. Mercury condensed from the vapor in banks of vertical pipes joined alternately at the top and bottom with U- connections. (3) Two D retorts with a total capacity of about one ton per day were used to burn soot from the condensing columns.(1,4) Liquid mercury was collected under water which sealed the hopper openings in the lower pipe connections.(3) The waste rock was deposited parallel to and on the east side of Wilson Creek. (1,2) A dust collector was used to separate the dust from the gases.(1) This in turn was washed out every ten minutes.(1) The resulting slurry was directed to a settling pond.(1) 2.2.2 Caputo & Wagner/Piombo Corporation The gravel crushing operations utilized the tailings piles for aggregate.(2) A bull-dozer pushed material from the piles into a piled mixture.(8) This material was picked up from these piles by a bucket line for further processing by crushing.(8) The blended aggregate was less red than the material in the burnt ore pile. (8) At the time of the June 10, 1980 DHS inspection, the gravel was not being washed or wet down before loading on the transport trucks.(8) A water sprinkler was used to keep down dust in the areas of traffic within the site.(8,9) According to the May 5, 1980 RWQCB report on the Piombo aggregate operation, dust control water was obtained from a 40 foot well on the property.(9) Excess dust control water, according to the report, flowed to a small pond at the southeast side of the lower level operations. This small pond (no. 1) also accepted some site runoff and overflowed to a small ditch and then to another Pond.