A10_AttachD.2_ExampleScenario1.docx

Solicitation Number: 12970223R0014 Region 5 CERCLA Environmental Response IDIQ Page 1 of 6 Special Projects Operation Center – Southwest Region Contractor(s) TBD

Attachment D.2 Example Scenario 1 – Preliminary Assessment & Site Inspection

For the scenario provided below, prepare, and submit:

· A conceptual PA/SI work plan that provides a description of how contractor would address the scenario. The work plan needs to include and address the following:

· Description of the work to be performed, including site investigation methodology.

· Discussion of any specific exclusions/assumptions the contractor may have regarding their response to the scenario in question.

· Conceptual listing of personnel, including subcontractor(s) that would be utilized for the response.

· Conceptual listing of equipment and supplies to be utilized for the investigation.

· Safety & Health Plan and procedures the contractor will follow.

· Field sampling and analysis protocols that would be utilized.

· Price Proposal to accompany the conceptual PA/SI Workplan.

· Example of a PA/SI Report that the firm has prepared.

SITE SCENARIO:

Contractor shall conduct Preliminary Assessment/Site Investigation (PA/SI) under Activity I, Task 3 of the Regional Environmental Response Contract.

Location and Background:

The Forest Service, an agency within the U.S. Department of Agriculture, is currently investigating the release of hazardous substances at the Black Bob Mine and Mill Site (hereinafter referred to as the "Site") in the Los Padres National Forest. Mt. Pinos Ranger District, Los Padres National Forest. The Black Bob mine site is located in Kern County about 33 miles due south of Bakersfield, California (Fig. 1). The geographic coordinates are Latitude 34o 52’ 18” North and Longitude 118o 59’ 21” West, San Bernardino Baseline and Meridian. The legal description for the Site is the SW1/4, Section 10, Township 9 North, Range 20 West, SBBM. This location is wholly on National Forest System land administered by the Mt. Pinos Ranger District, Los Padres National Forest.

The Site is on the north-draining slopes of the San Emigdio Mountains (Fig. 2). Its elevation is about 4800 feet. The Black Bob mine site lies in the bottom of Black Bob Canyon just upstream from its junction with Bradley Canyon. Black Bob canyon is a tributary to Salt Creek, which flows to the north into the Central Valley. The Black Bob mine site claim encompasses about 5 acres.

The site is reached by taking Interstate 5 south from Bakersfield to the Lavell Road exit. A gated, private road permits crossing of the California Aqueduct and passage for about 7 miles on a native surfaced road to the mouth of Black Bob Canyon. From this junction, it is a 3.7 mile hike following an abandoned road bed to the tailings piles and other features at Black Bob mine site. Site is accessible via high clearance four-wheel drive vehicles. Access to some site features will require foot travel over uneven, steep terrain.

Site History:

The Black Bob mine is a gold mine on the north side of Tecuya Ridge within Black Bob Canyon. The nearest gold mining area to this site is the Frazier Mountain Mining District about 5 miles to the south. While the Black Bob claim was initially located in 1902 and 1903, respectively, the primary production period from these mines occurred between 1932 to 1938 and from 1952-1956. Production is reported to be 558 oz. of gold and 767 oz. of silver. Historic documents indicate that cyanide was used in the gold extraction process at the site. In March 1989, the Bureau of Land Management declared the claims associated with this site Abandoned and Void

The Black Bob mine adit was about 300 feet (vertically) above the mill site. U. S. Bureau of Mines file notes indicates a 5-stamp mill was present at the mill site. Currently the stamp mill foundation, a cabin, storage building, two tailings’ piles and what appears to be a settling pond are the only features present at the Black Bob mill site. Both tailings piles are within the ephemeral drainage bottom along which Black Bob Road passes. The smaller pile (Tailings Pile #1) was estimated to contain less than 80 cubic yards of material and is a mix of rocks, soil, and mill waste. The second, larger tailings pile (Tailings Pile #2) team was estimated to be 260 feet long, 35 feet wide and about 2-8 feet thick. They estimated it contains about 2000 cubic yards of material.

Previous Investigations:

In 1995 the Los Padres National Forest (LPNF), completed a limited Preliminary Assessment (PA) at the Site. The purpose of that investigation was to collect information concerning conditions at the Site sufficient to assess the threat posed to human health and the environment and to determine the need for additional CERCLA or other appropriate action.

Forest Service personnel observed various barrels on site some which appeared to contain petroleum products (grease and oil) and other containers in the former storage building with unknow white powdery material. The tailings piles and soils near the former stamp mill were found to be devoid of vegetation. In addition, two (2) 76-pound capacity mercury flasks were found in the storage building. Both flasks were found to contain mercury and were removed from the site and disposed of.

Limited sampling of the tailings piles was conducted. The exact locations of the samples taken are unknown. Reported results in Table 1 show the concentration of arsenic, lead, and mercury found in Tailings Pile #1 (sample TP-1) and Tailings Pile #2 ((sample TP-2).

Adit drainage has been observed in the past during periods of heavy rainfall, but has not been sampled. Subsequent site visits have observed signs of site visitation and recreational use (building vandalism, trash, empty beer cans and tire tracks though the site and on the tailings piles).

Description of Work:

Conduct a combined Preliminary Assessment/Site Inspection (PA/SI) for the Edna Camp Mine Site.

Conduct a combined Preliminary Assessment/Site Inspection (PA/SI) on the Site as per Activity I, Task 3 of the Region 5 Environmental Response Contract. The combined PA/SI shall include maps delineating sources of hazardous substances and sampling locations in accordance with the requirements of the Regional IDIQ SOW. The combined PA/SI shall also include sample data and analysis of the data.

The PA/SI report shall include recommendations of further actions or conclusions, including the completion of a narrative report in accordance with EPA’s latest guidance documents, including but not limited to:

1. Guidance for Performing Preliminary Assessments Under CERCLA, EPA Publication 9345.0-01A, September 1991.

2. Guidance for Performing Site Inspections Under CERCLA, EPA Publication 9345.1-05, September 1992.

3. Improving site assessment: Combined PA/SI Assessments, EPA-540-F-98-038, October 1999

The contractor shall furnish personnel, services, materials, and equipment required to support/conduct combined PA/SI assessment activities. The combined PA/SI assessment integrates activities typically performed during the PA (information gathering, site reconnaissance) with activities typically performed during the SI (review of data, development of field work plans, field sampling, filling data gaps) to achieve one continuous site investigation.

Activities performed pursuant to this requirement shall be consistent with the NCP.

Key data collection and analysis objectives, include, but are not limited to:

· Determine nature and extent of contamination, including an estimate of volumes and quantities of contaminated materials, adit discharge and any hazardous substances which may be present in containers left on the site.

· Surface water and sediment sampling. Water and sediment samples shall be collected at the portal of the mine adit, any seepage from the tailings piles, at various locations in the drainage below the mine.

• Bioavailability analysis of key contaminants.

· Metals leachability analysis to determine California mining waste classification (acid/base accounting analysis (ABA), and California WET test for leaching potential).

· Based on the results of the field investigation prepare

· Streamlined Human Health Risk Assessment for the Site based on public visitation and site use.

· Provide a preliminary evaluation of potential remedy alternatives and recommendations for further action.

Work activities under this task include but are not limited to the items listed in Activity 1, Task 3 of the Region 5 Environmental Response Contract. In the performance of this task, the Contractor shall use existing data to the maximum extent practicable. Note, that the focus of the investigation is not to collect data for the generation of a HRS score, but to document releases and human health and environmental receptors and exposure. For remote sites such as abandoned mine lands HRS scoring is not completely applicable. The Contractor shall provide clear technical justification for the type and number of samples.

The Contractor is expected to conduct the optimal sampling necessary to achieve the objective of site characterization. It is ultimately up to the Contractor to propose the number, type and location of environmental samples they feel is necessary in order to adequately characterize the site to meet objectives.

Project Deliverables:

PA/SI Work Plan- The contractor shall prepare a PA/SI workplan that describe the planned work activities, including a health and safety plan and a quality assurance sampling plan. The contractor shall submit the project work plans in draft for Forest Service review and acceptance before finalizing. Work plans must be finalized and approved prior to conducting any field work.

PA/SI Report- The PA/SI report shall include maps delineating the mine location in the watershed, mine features within the site, and sampling locations. The PA/SI report shall also include field notes, sample data and analysis, lab work, recommendations for further actions, conclusions, and the QA/QC information.

Figure 1 Map showing the general location of the Black Bob Mine.

Figure 2 Detailed topographic map showing the route (in red) along Black Bob Canyon to the Black Bob Mine.

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