GSA Annual Meeting in Seattle, Washington, USA - 2017

Paper No. 371-10
Presentation Time: 9:00 AM-6:30 PM

CHARACTERIZING THE GROUNDWATER OF THE UPPER PEARL RIVER WATERSHED IN CENTRAL MISSISSIPPI


VATTIKUTI, Shannon K. and PAUL, Varun, Geology, Mississippi State University (MSU), MS State, MS 39762, skv16@msstate.edu

Jackson, the capital of Mississippi, receives its drinking water from the Ross Barnett Reservoir (RBR). This reservoir is in turn fed by the Upper Pearl River, a fluvial system with its own separate watershed and an approximate area of 7,588 square kilometers. In the past, the RBR and Upper Pearl River Watershed (UPRW) have been reported to contain heavy metals, specifically mercury, trace elements, and fertilizers in higher than normal concentrations than in the past. Hypothetically, these contaminants infiltrate into the groundwater and may diffuse into the Pearl River by base flow and connecting streams, finally being transported into the RBR.

The groundwater of the UPRW was characterized by selecting and analyzing twelve wells that best represented the land use and land cover of the study area. A geologic map of the UPRW was used to determine water-bearing rock units, non-water-bearing rock units, and well depths needed to reach the groundwater at each specific well sites. Triplicate of groundwater samples were collected from pumping wells from Leake County and a gravity-fed groundwater spring in Winston County, which represents approximately one-fifth of the study area. Parameters, such as pH, alkalinity, and hardness were analyzed in-situ. Preliminary results from the analyzed groundwater well samples show that the water has a pH ranging from 7.76 – 8.61 and a total alkalinity ranging from 70 ppm – 190 ppm. Calcium and magnesium concentration varied between 2.4 ppm - 31 ppm, and 5.6 ppm - 116.2 ppm, respectively, as determined by calcium and total hardness.

The groundwater samples are currently being analyzed for trace and heavy metal analysis. This data will be combined with the regional land use/land cover classification scheme for comparative analysis of possible point-source pollution sites. Precipitation and discharge data will be included for analysis. Of the twelve wells, two wells will also be tested for pharmaceuticals - Philadelphia and Carthage respectively, the largest cities in the study area. To this end, the well water analysis along with all geologic and land use/land cover maps stated above, will further help hydrogeologists to characterize the groundwater of the UPRW and understand its relationship with RBR.


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