Pacific Northwest National Laboratory (PNNL) conducted a proof-of-principle test at the Fort Lewis Logistics Center to determine the feasibility of using the In Situ Redox Manipulation (ISRM) technology for remediating groundwater contaminated with dissolved trichloroethylene (TCE). ISRM creates a permeable treatment zone in the subsurface to remediate redox-sensitive contaminants in groundwater. The permeable treatment zone is formed by injecting a chemical reducing agent (sodium dithionite with pH buffers) into the aquifer through a well to reduce the naturally occurring ferric iron in the sediments to ferrous iron. Once the reducing agent is injected and given sufficient time to react with aquifer sediments, residual chemicals and reaction products are withdrawn from the aquifer through the same well used for the injection. Redox-sensitive contaminants such as TCE, moving through the treatment zone under natural groundwater flow conditions, are destroyed. TCE is degraded via reductive dechlorination within the ISRM treatment zone to benign degradation products (i.e., acetylene, ethylene). Prior to the proof-of-principle field test, the ISRM technology was successfully demonstrated in laboratory experiments for the reductive dechlorination of dissolved TCE using sediments from the Fort Lewis site. The Logistics Center was placed on the National Priorities List in December 1989 because of TCE contamination in groundwater beneath the site. A Federal Facilities Agreement between the Army, the U.S. Environmental Protection Agency, and the Washington State Department of Ecology became effective in January 1990, and a Record of Decision (ROD) was signed in September 1990. The major components of the ROD included installation of two pump-and-treat systems for the upper aquifer and further investigation of the lower aquifer and other potential sources of contamination. The pump-andtreat systems became operational in August 1995. Fort Lewis asked PNNL to provide technical support in accelerating Installation Restoration Program site remediation and significantly reducing site life-cycle costs at the Logistics Center. In support of this program, ISRM was selected as an innovative technology for bench and field-scale demonstration. Emplacement of the ISRM treatment zone was accomplished through a series of four separate dithionite injection tests conducted between November 10, 1998 and March 29, 2000. An extensive program of chemical monitoring was also performed before, during, and after each injection to evaluate the performance of ISRM. Prior to emplacement of the ISRM treatment zone, the site was extensively characterized with respect to geologic, hydrologic, and geochemical properties. Sediment core samples collected for the characterization studies were analyzed in bench-scale column tests at PNNL to determine reducible iron content. These site-specific hydrogeologic and geochemical data were used to develop the emplacement design of the pilot-scale (i.e., single injection well) ISRM treatment zone. Performance data...

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Abstract. Theexperimental andtheoretical development of ion cyclotronradofrequency heating (ICRF)intoroidalmagnetically-confined plasmasrecentlyculminatedwith the demonstration of ICRFheatingof D-Tplasmas, firstin theTokamakFusionTestReactor(TFTR)and then in the Joint EuropeanTorus (JET). Variousheating schemesbased on the cyclotronresonances betweentheplasmaionsandtheappliedICRFwaveshavebeenused,includingsecondharmonic tritium, minoritydeuterium, minorityhelium-3,modeconversionat the D-T ion-ion hybrid layer,andandionBernstein waveheating. Secondharmonictritium heatingwasfirst shownto be effectivein a reactor-grade plasmain TFTR. D-minorityheatingon JET has led to the achievement of Q = 0.22,theratioof fusionpowerproducedto RFpowerinput,sustainedovera few energyconfinementtimes. In this paper, some of the key building blocks in the development ofrf heatingofplasmasarereviewedandprospectsfor the development of advanced methodsof plasmacontrolbasedontheapplication ofrf wavesarediscussed.

The water quality and aquatic resources of the upper Animas River watershed are affected by more than 1,500 abandoned mines from historical metal-mining activities in the late 1800's and early 1900's. In 1997, the U.S. Geological Survey implemented the Abandoned Mine Lands Initiative to provide scientific information to Federal land-management agencies responsible for remediation of abandoned mine sites on publicly owned land. This report presents hydrologic and water-quality data collected as part of the Abandoned Mine Lands Initiative during water years 1997-99 in the upper Animas River watershed, Colorado. Water-quality samples were collected from four streamflow-gaging stations, nine sites along the main stem and two major tributaries, 55 abandoned mine sites, and 194 selected stream and spring sites. Data include field measurements of streamflow, specific conductance, pH, water temperature, and dissolved oxygen and laboratory analyses of major inorganic and selected traceelement constituents. Daily mean discharge values are tabulated for the four streamflowgaging stations. A CD-ROM containing hydrologic and water-quality data is in the pocket of this report.

Geochemical and hydrologic studies were conducted on parts of the Arkansas River and its flood plain downstream from Leadville, Colorado, to assess the effects of fluvial tailings deposits on soil and water quality, to identify processes causing water-quality degradation, and to identify implications of these results for remediation strategies. Soil samples indicated that the tailings deposits in a 3-mile reach of the flood plain contain as much as 6,500 and 12,000 milligrams per kilogram of lead and zinc, respectively. These concentrations are as much as 380 times the reported average concentrations for soils in the Western United States. Pyrite and some of its weathering products were identified in the soils, indicating that acid-rock drainage can occur. Estimates of instantaneous mass loads for calcium, iron, lead, manganese, and zinc in unfiltered Arkansas River samples for 18 different sampling dates in 1996 showed some evidence for increases in trace-element loads in some stream reaches during a few sampling dates during snowmelt runoff. These data indicate erosion of sediments or addition of trace elements to the water column in these stream reaches. Conversely, on some dates, during low flow, downstream loads decreased, indicating deposition of sediments or formation and settling of iron and manganese oxyhydroxide minerals, or both. For most of the 5 milligrams per liter) in one of the most upgrdient wells indicate contamination of ground water from upgradient tailings sources. Durin spring, a flush occurs that increases the areal extent of degraded ground water. The spring flush is from increased infiltration of springti e snowmelt through the tailings, or from season fluctuation of the groundwater table and capil ary fringe up into tailings material, or both. An understanding of the mechanism causing groundwater contamination is impo for remedial activities. If infiltration is the contamination mechanism, then shallow arne dments of acid-neutralizing material and effort to limit infiltration might be sufficient to remedi te adverse effects of the tailings deposits. Howe er, if water-table fluctuation is the mechanism, th n deeper amendments of acid-neutralizing mate • al would be required. In this case, a remedial effi rt would require detailed information about the depth, distribution, and acid-generating capac"ty of the tailings material.