Borden, R.C., J.M. Tillotson, G.-H.C. Ng, B.A. Bekins, D.B. Kent, and G.P. Curtis.
SERDP Project ER-2131, 76 pp, 2015

Although electron donor addition can be very effective in stimulating enhanced reductive bioremediation (ERB) of a wide variety of groundwater contaminants, ERB can result in secondary water quality impacts (SWQI), such as decreased levels of dissolved oxygen, nitrate, and sulfate, and elevated levels of dissolved Mn, dissolved Fe, methane, organic carbon, and naturally occurring hazardous compounds (e.g., As). This report summarizes available information on processes that control the production and natural attenuation of SWQI parameters and can be used as a guide in understanding the magnitude, areal extent, and duration of SWQI in ERB treatment zones, and the natural attenuation of SWQI parameters as the dissolved solutes migrate downgradient with ambient groundwater flow. Information compiled from a variety of sources, including a survey and statistical analysis of SWQI from 47 ERB sites, was integrated to provide a general conceptual model of the major processes controlling SWQI production and attenuation. https://www.estcp.com/content/download/39498/379977/file/Protocol%20for%20Evaluating%20MNA%20of%20SWQI%20V2%20ER-2131%20--%20September%202015.pdf