Remediation of Abandoned Mine Lands

Friday, October 3, 2008 : 12:00 p.m.

Source Treatment of Acid Rock Drainage at a Backfilled Coal Mine

Song Jin, Ph.D., CHMM, Jeffrey M. Morris, Ph.D. and Paul H. Fallgren, M.S., Western Research Institute

A biological source treatment (BST) technique using remote sensing and biogeochemistry has been developed to address acid rock drainage (ARD) at its source.  The BST technique utilizes down-hole injections of microbial inoculum and substrate amendments to establish a biofilm on the surface of metal sulfides (ARD source material).  The treatment results in an elevated groundwater pH (from acidic to circum-neutral levels) and prevents further oxidation of ARD source material.  The first 2.5 years of an ongoing field study of the BST technique at a reclaimed coal mine in central Tennessee (USA) have produced successful results.  For instance, the water chemistry in a monitoring well down-gradient from injection wells has improved substantially as follows: the pH increased 1.8 units from 5.7 to 7.5, the dissolved (0.45 µm-filtered) iron concentration decreased by 91% from 93 to 8 mg/L, the conductivity decreased from 1,279 to 500 µS/cm, and sulfate decreased from 724 to 210 mg/L.  Electromagnetic induction surveys were conducted to identify ARD source material and monitor BST performance by measuring changes in subsurface resistivity throughout the site.  These surveys revealed a treatment zone created between injection wells where the conductivity of contaminated groundwater was lower within the treatment zone (10-18 mS/m) than in adjacent untreated zones (20-30 mS/m), thus, suggesting this technique could be used to treat ARD sources directly or to intercept and neutralize sub-surface ARD. 

Song Jin, Ph.D., CHMM, Western Research Institute Song Jin, Ph.D., CHMM: Principal Scientist, WRI. Ph.D. Univ. of Wyo., 1997. Biogeochemical pathways in degradation and transformation of organic, metal and other constituents in aerobic and anaerobic environments. Adjunct Professor, Department of Zoology and Physiology, UW.

Jeffrey M. Morris, Ph.D., Western Research Institute Jeff Morris, Ph.D.: Lead Scientist, WRI. Ph.D. Univ. of Wyo., 2005. Aquatic toxicology, diel metal cycling in mining impacted waters, and bioremediation of acid mine drainage. Adjunct Professor, Haub School of Environment and Natural Resources, UW.

Paul H. Fallgren, M.S., Western Research Institute Paul Fallgren: Senior Scientist, WRI. M.S. Univ. of Wyo., 2007. Remediation of organics- and inorganics-contaminated soils, sediments, and water by biological, chemical, and electrochemical pathways.


Remediation of Abandoned Mine Lands