Groundwater contamination by landfill generated leachate is a problem that is increasingly addressed for proposed and existing landfill sites.This thesis examines groundwater contamination movement from the abandoned Delaware County Municipal landfill. The site is located in the crest of a highly permeable sand and gravel glacial esker which allows for rapid movement of ground water and any contaminants introduced into it.The landfill site was originally investigated in the late 1970's by Ed Lusch, a graduate student at the Ball State University Geology Department. That study showed some indications of ground water contamination movement to about 400 feet west of the site, in the direction of ground water flow. This indicated position of a contamination plume suggested that leachate, generated from the landfill site, had moved to that position since (or possibly before) the closing of the landfill in 1971.The present study, using a combination of surface resistivity methods, on-site test wells, and chemical analyses of ground water, attempted to determine the degree of contamination movement from the site since the original study and the extent to which the local aquifer had been affected. Results of this investigation revealed an apparent slow movement of leachate from the landfill westward towards the Mississinewa River, also in the direction of ground water flow. Surface resistivity methods of this study revealed the plume of contamination (indicated by resistivity "low" area) to now exist at approximately the same location as indicated in the earlier study, but to have expanded laterally. This investigation also found indications of the contamination plume well into the underlying fractured dolostone.Chemical analyses of nearby residential wells also revealed slightly elevated amounts of chloride, ammonia and specific conductivity in the ground water of the glacial esker south of the abandoned landfill site. The presence of three other dump sites, including a sludge dump, along the esker south of the landfill, offers questions as to the source of ground water contamination.Ball State UniversityMuncie, IN 47306

Indiana University-Purdue University Indianapolis (IUPUI) / Groundwater monitoring networks are subject to change by budgetary actions and stakeholder initiatives that result in wells being abandoned or added. A strategy for network design is presented that addresses the latter situation. It was developed in response to consensus in the state of Indiana that additional monitoring wells are needed to effectively characterize water availability in aquifer systems throughout the state. The strategic methodology has two primary objectives that guide decision making for new installations: (1) purposive sampling of a diversity of environmental variables having relevance to groundwater recharge, and (2) spatial optimization by means of maximizing geographic distances that separate monitoring wells. Design objectives are integrated in a discrete facility location model known as the p-median problem, and solved to optimality using a mathematical programming package.

Indiana University-Purdue University Indianapolis (IUPUI) / Numerous studies have investigated the fate of pollutants in riparian buffers, but few studies have focused on the control of multiple contaminants simultaneously in riparian zones. To better understand what drives the biogeochemical cycles of multiple contaminants in riparian zones, a 19-month study was conducted in riparian buffers across a range of hydrogeomorphic (HGM) settings in the White River watershed in Indiana. Three research sites [Leary Webber Ditch (LWD), Scott Starling (SS) and White River (WR)] with contrasting hydro-geomorphology were selected. We monitored groundwater table depth, oxidation reduction potential (ORP), dissolved oxygen (DO), dissolved organic carbon (DOC), NO3-, NH4+, soluble reactive phosphorus (SRP), SO42- , total Hg and methylmercury (MeHg). Our results revealed that differences in HGM conditions translated into distinctive site hydrology, but significant differences in site hydrology did not lead to different biogeochemical conditions. Nitrate reduction and sulfate re-oxidation were likely associated with major hydrological events, while sulfate reduction, ammonia and methylmercury production were likely associated with seasonal changes in biogeochemical conditions. Results also suggest that the LWD site was a small sink for nitrate but a source for sulfate and MeHg, the SS site was a small sink for MeHg but had little effect on NO3-, SO42- and SRP, and the WR was an intermediate to a large sink for nitrate, an intermediate sink for SRP, and a small source for MeHg. Land use and point source appears to have played an important role in regulating solute concentrations (NO3-, SRP and THg). Thermodynamic theories probably oversimplify the complex patterns of solute dynamics which, at the sites monitored in the present study, were more strongly impacted by HGM settings, land use, and proximity to a point source.