Can we solve the water problem in chromite mine area?

Sukinda Valley contains 97% of India's chromite ore deposits and is one of the largest open cast chromite ore mines in the world.  Approximately 70% of the surface water and 60% of the drinking water contains hexavalent chromium. The levels of contamination are more than double national and international standards. Levels of over 20 times the standard have been recorded.  How should the contaminated water be treated? Is there a simple method of treating extremely contaminated water and how can the groundwater contamination from these mines be prevented?