Case Study as part of a Web-based
Technical and Regulatory Guidance
Alpine County-2, California
Enhanced Semi-Passive Sulfate-Reducing Bioreactor
1. Site Information
1.1 Contacts
Ionic Waters Technologies
Vance Weems
Telephone: 775-321-8101
Dr. Timothy Tsukamoto
Telephone: 775-321-8101
wvmdtaskforce.files.wordpress.com/2016/01/06-tsukamoto.pdf
1.2 Name, Location, and Description
The site is located in the Sierra Nevada mountains on an inactive, open-pit
sulfur mine. Acid mine discharge (AMD) leaches from a waste rock dump at
a flow of 5–40 gallons per minute and directly affects the immediate drainage
and subsequent waterways from the site. The site is remote and inaccessible
through ordinary means of travel two to six months of the year. There is
no power available on site, and snow depths can approach 6 feet.
2.
Remedial Action and Technologies
The ethanol-enhanced, semi-passive, sulfate-reducing bioreactor can be operated
on less than 1 kw of electricity. Metals are removed outside of the
bioreactor matrix, and carbon source is continually supplied at stoichiometric
concentrations. The system requires operation and maintenance checks every
two weeks. It has been operating for 13 total years and 6 years on the current
system.
3. Performance
This bioreactor system has been upgraded and improved throughout the last
13 years to incorporate a design which is sustainable and energy-efficient
and can be operated throughout the year with minimal maintenance requirements.
Sludge and precipitated metals are removed previous to entry into the bioreactor
cells, limiting system short-circuiting and metals loading. The ethanol-delivery
system provides a carbon source that is not depleted over time, eliminating
the need to remove and replace the substrate.
4. Costs
Cost of activities at these site are reported as a total:
- Capital: $ 800,000
- Operation and maintenance: $ 75,000 annually
5. Regulatory Challenges
No regulatory challenges were encountered.
6. Stakeholder Challenges
No information available from survey.
7. Other Challenges and Lessons
Learned
See information under performance.
8. References
No information available.