There has been increased exploitation of groundwater due to rapid development and urbanization in terms of quality and quantity over the last decades.  Federal water quality regulations have challenged the groundwater research community to develop methodologies for assessing vulnerability of groundwater contamination by anthropogenic activities.  In this regard, an index-based, multi-criteria decision making approach, DRASTIC (an acronym for D- Depth to water table; R-aquifer Recharge; A-Aquifer media; S- Soil media; T- Topography; I- Impact of vadose zone; C- Conductivity) methodology is the most widely used.  Although the approach has great practical utility, there are several structural and parametric limitations to the DRASTIC approach that limit its functionality.  These limitations are due to intrinsic geologic uncertainty and subjectivity arising due to decision makers’ preferences in assigning weights to the parameters.  And when the task is associated with funding decisions or identifying potential sites for regional-scale hazardous waste landfills and other NIMBY structures, it often requires ranking of administrative units.  Looking at the uncertainties in methodology and subjectivity due to decision makers’ preferences, it is a difficult task.  Data Envelopment Analysis (DEA), a non-parametric method, is being used as an alternative for multi-criteria decision making analysis, when there is subjectivity in weights of the inputs in a decision making problem.  In DEA, the decision maker does not need any prior information about weights of the inputs and outputs.  In this proposed research, DEA is used with DRASTIC to rank counties based their groundwater pollution potential.  Geographic Information System (GIS) is used extensively in DRASTIC method.  Since, DEA is an objective approach, there will be no assigning of weights to the inputs.  The study is illustrated for several counties in South Texas.  This innovative method will be fairly easy to implement and be of interest to policy makers and land use planners.