Oro De Amador

Project Profile
Oro De Amador
Location: Jackson Owner: City of Jackson
Total Project Value: Unknown
Consultant/Engr. Cost: $45,000
Square Footage/Area: 159 acres
Completion Date: On-going

The 159-acre property was purchased by the City of Jackson in December 2006 from Oro De Amador, Inc. By 1914 a series of four 90- foot diameter wheels were constructed to transfer mine tailings the one-quarter mile from the Kennedy Mine site to the Property. A 600-foot long by 60-foot high multi-arch concrete dam was built to store the tailings. By developing the Property, the City can offer the community, an all-inclusive recreation and historic park with reflections of California mining.

Project Challenges

By the time of the Kennedy Mine closure in 1942, approximately 1.5 million tons of tailings had been moved from the mine to the Property. Between 1933 and 1939, a 1,000 ton per day cyanide leaching plant was constructed and operated on the Property. Approximately 1.25 million tons of tailings were processed in the cyanide plant. The City plans to develop a community park on the Property that preserves the existing structures and includes walking/biking trails, picnic areas, and sports fields. To accomplish this dream, the City needed to identify the prevalence of toxins on the Property and assess their potential risk to human health.

Stratus Solutions

Stratus personnel assisted the City with the environmental due diligence review. The process began with a review of the several thousand documents provided by Oro De Amador, Inc. including previous site analysis and reports related to the Property. Information contained within these documents ranged from easement information to detailed hazardous materials testing performed by engineering firms in previous years. Stratus personnel made several site visits and performed additional environmental testing on the Property for comparison with data previously collected. The general conclusion of this observation and testing is that site conditions have remained fairly constant. The testing and evaluation addressed potential concerns regarding groundwater, one of the critical areas of the due diligence review. Results from this testing indicated that arsenic is present but below the regulated levels, and there was no detection of cyanide or mercury in the groundwater. In July 2007, Stratus personnel prepared an industrial SWPPP for the property pursuant to guidelines set forth in the California State Water Resources Control Board Water Quality Order No. 97-03-DWQ (Industrial Storm Water General Permit).