The Keystone, Early Bird, Balaklala, and Shasta King mines are a series of inactive copper mines located near Redding. The mines discharge acid rock drainage from portals, seeps, and waste rock dumps.

VESTRA worked with the mine owner, Mining Remedial Recovery Company (MRRC) to develop a Use Attainability Analysis (UAA), the first in the state to address inability to reach compliance under the Clean Water Act (CWA). The UAA is a process under CWA that allows evaluation of attainable uses under current technologies and allows for portions of beneficial uses to be abandoned if they cannot be recovered.

The development of the UAA requires investigation and characterization of pre-mining and post-mining conditions of the area, including the chemical constituency of the watershed, the various components of mine sites, and a detailed biological assessment of current conditions. VESTRA developed a comprehensive database, including more than 40 years of water-quality data to support the UAA requirements.

VESTRA coordinated the water-quality monitoring and bioassessment programs being conducted by MRRC and the California Department of Fish and Game, reviewed remediation actions conducted by MRRC to determine their effectiveness and practicality, compiled a record of historic and current water-quality parameters, and assembled the UAA document.