Abstract: A new and improved method for treating mine influenced water (MIW) or other environmental contamination is disclosed. A number of electron donors are disclosed, including chitin complex-containing materials. The chitin complex-containing materials may modify the pH and reductive-oxidation potential of the contaminated media within the subsurface or within a treatment cell to facilitate metal removal through biological, chemical, and physical means, or a combination thereof. Bioremediation enhancing agents such as yeast products may also be used to facilitate microbial treatment of the contaminated sources. The yeast products may work with microbes to improve the rate of contaminant removal and promote microbial growth.