TA10 Microbial Remediation of Acid Mine Drainage Wastes
D135-136
8:00 AM - 12:00 PM, Tuesday
() Multi-Test Cell Treatability Study for the Prevention of Acid Mine Drainage at the Gilt Edge Superfund Site, Lawrence County, South Dakota.
Lewis, N1, Trudnowski, J2, Wangerud, K3, Fundingsland, S4, Jonas, J4, 1 USEPA, ORD, NRMRL, Cincinnati, OH, USA2 MSE, Applications, Inc., Butte, MT, USA3 USEPA, Region VIII, Denver, CO, USA4 CDM, Denver, CO, USA
ABSTRACT- Three technologies were selected to be demonstrated through the Mine Waste Technology Program (MWTP), within the Environmental Protection Agency's (EPA), National Risk Management Research Laboratory (NRMRL), Cincinnati, Ohio. This project is in collaboration between EPA Region VIII, Superfund Remediation Program, and contractor CDM Federal Programs Corporation. The EPA, MWTP has an Interagency Agreement with the Department of Energy (DOE), who contracts work efforts with MSE, Application, Inc. The objective of the project was to generate performance data and cost information for the applied technologies for preventing the oxidation of sulfide waste rock, which may be applicable to these problems or other similar sites situations. The applied technologies were compared to the presumptive remedy of lime treatment as well as two controls in which no treatment was performed. The project involved constructing twelve test cells, which were filled with sulfide-bearing waste rock from the Gilt Edge Mine site located near Deadwood, South Dakota. EPA Region VIII assisted by the U.S. Bureau of Reclamation designed and constructed the test cells as well as loading the waste rock. Three technology providers applied their respective technology for reducing Acid Mine Drainage (AMD) generated by the waste rock. The twelve test cells constructed consisted of, two cells for each of the technologies (totaling 6) to establish repeatability. Three control cells containing only waste rock (with no additional treatment) and three cells representing the presumptive remedy of blending lime with the waste rock. The project began November 2000 with treatment monitoring beginning in May 2001, and continuing until December 2002. _CR__LF__CR__LF_The three technologies demonstrated were: Silica microencapsulation [Klean Earth Environmental Company (KEECO)]; Environbond [Metals Treatment Technologies (MT2)] and Passivation technology [Mackay School of Mines, University of Nevada, Reno (UNR)]. Data analysis from the sampled leachate included comparing parameters of each leachate to the South Dakota Water Quality Criteria (SDWC) applicable to the Gilt Edge mine. Two indicators that reflect overall effectiveness are the total dissolved solids (TDS) concentrations and the pH trends of each technology. The presumptive remedy cells of 4, 7, and 12 all reached the SDWC of 2500 milligrams per liter (mg/L). The UNR cell 3 trend was very close to the 2500 mg/L limit. The SCWC pH range is 6.5 to 8.8. The MT2 cells 5 and 11 trends were within this range for the duration of the test, while UNR cell 3 was in the range for the majority of the test._CR__LF__CR__LF_The technologies were evaluated in 2002 using a residual wall rinse sampling method and a modified humidity cell testing method. The humidity cell testing was extended to 41 weeks and was completed in Fiscal Year (FY) 03, the final report is currently available.
Key words: Hard Rock Mining, Acid Mine Drainage, Metal Toxicity, Sulfate reducing Bacteria (SRB)