Bully Hill and Rising Star Mines

Mine Remediation and Passive Treatment - East Shasta Mining District, Shasta County, California

Shasta County was a leading producer of copper in the United States between 1900 and 1920.  Following the closure of the local copper mines in the early 1920s, acid rock drainage (ARD) from the closed mines was identified as a major source of metals contamination in the Sacramento River.  ARD is generated when air and water interact with the metal sulfide deposits to produce sulfuric acid.  The acid dissolves the metals and the contaminated water discharges to the surface through the mine workings. 

VESTRA staff have been involved in ARD remediation for over 20 years, including several projects in Northern California.  One of these projects, the Bully Hill and Rising Star mines, included many of the remedial activities implemented to address ARD contamination.  The Bully Hill Mine consists of two main portals and a large waste rock pile, and the Rising Star Mine consists of eight portals and one large and numerous small waste rock piles.  Both mines are located on Shasta Lake in an area with no power, water, or phone service.  Site access is by boat or 4-wheel drive vehicle via logging roads.

Activities completed at the Bully Hill and Rising Star mines included source identification, source control and reduction, and treatment of residual ARD.   

• Site Characterization.  Representative water samples and continuous recorder data were collected to characterize metal concentrations and flow rates for approximately 5 years.  These data were used to prioritize the ARD sources for remediation.

• Portal and Tunnel Rehabilitation.  Once the sources were prioritized, it was necessary to access the source areas.  In most cases, access involved rehabilitating the mine tunnels and installing several bulkhead seals to control the ARD.  Overall, approximately 350 feet of mine tunnel was rehabilitated, five bulkhead seals were installed to capture the ARD, and high-pressure piping and values were installed through the bulkheads to control the ARD.

• Waste Rock Consolidation and Capping.  In addition to discharge from the collapsed portals, it was determined that exposed waste rock was also a source of ARD.  Waste rock in the vicinity of the Rising Star Mine was consolidated and capped with a synthetic liner and vegetative cover.  

• Passive Treatment Systems.  Although ARD may cease following the installation of a bulkhead seal, the more likely outcome is a significant reduction in flow.  When this occurs, it is necessary to design and construct a treatment system to remove the metals contamination from the residual seepage prior to discharge.  Pilot and full-scale sulfate reducing bacteria (SRB) anaerobic treatment systems were constructed at the Bully Hill and Rising Star mines.  Each system is gravity-based and was designed to treat up to 25 gallons per minute.  Based on the pilot systems, the final substrate mixture includes wood chips, hay, limestone, agricultural limestone, manure, and rice hulls.  The Bully Hill system has been operating for 4 years and reduction in concentrations exceeds 99 percent for copper, zinc, and iron and 80 percent for aluminum.  The average effluent pH is 7.00 units.  The treatment system at the Rising Star Mine has been operating for 2 years with similar success rates.

Humboldt Burn Dump Remediation

The Humboldt Road Burn Dump (HRBD) is a collection of adjacent public and private properties totaling approximately 157 acres near the intersections of Bruce Road, Humboldt Road, and Highway 32 in Chico, California.  The City of Chico owned and operated the main landfill/burn dump from the early 1900s to approximately 1965 when the Butte County Neal Road Landfill was opened.  The HRBD has been the subject of extensive investigations and controversy. Cleanup of the site had been stalled since 1992 by regulatory agencies and environmental groups. VESTRA was retained by one of the private properties owners to “get the job done.”

VESTRA was able to permit, design, and complete the first phase of remediation in less than 6 months. This included the preparation and submittal of a Draft and Final Environmental Impact Report. VESTRA coordinated permitting with state and federal agencies including CDFG, ACOE, DTSC, State Water Quality Control Board, and the USFWS.  Permits required to implement the remediation plan included Waste Discharge Requirements, 404 Water Quality, Section 7, Clean Water Act 401, DFG 1603 permit, and air permit with the Butte County Air Quality Management District (AQMD).  Required design plans included a Remedial Action Plan and a Remedial Design Implementation Plan.  

The final project included consolidating approximately 180,000 cubic yards of burn ash and waste debris covering approximately 40 acres into a seven acre consolidation unit.  The consolidation unit was capped with a 2 foot compacted foundation layer, 60-mil HDPE liner, drainage layer and an 18-inch vegetative layer.  It took two years to complete the project as one of the permit conditions required all construction activities be conducted during the summer when a nearby school was out of session.  Following the successful completion of the permitting and construction activities, the lead agency issued a certificate of completion, the client successfully recovered the costs for the project, and the area is being developed.  After a 12-year regulatory and political stalemate, the entire project was completed in three years.        

Moores’ Flour Mill

Site civil design for Moores’ Flour Mill project in the City of Redding.  Design elements included a grading plan for the 11-acre site, extension of Shasta View Drive, water and sewer extensions, onsite storm drainage, and fire protection.  HEC-RAS analysis for the project was completed to determine the storm water detention for the facility.  A SWPPP was prepared for the site which detailed inspection and reporting requirements.

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Anderson-Cottonwood Irrigation District (ACID)

Irrigation ditch piping for Anderson-Cottonwood Irrigation District (ACID) laterals.  The project includes the conveyance ditch piping design.  The conveyance ditches are plagued with problems such as leakage/seepage, overgrown vegetation, and burrowing animals that compromise the integrity of the banks.  The project replaced the open ditches with pipelines, as well as complete on-farm irrigation pipelines with alfalfa valves.  Four to five projects per year have been completed since 2010.

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