Impact of Dyke on Hydrological and Hydrogeochemical Conditions in Nadergul Micro Watershed of Ranga Reddy District of Telangana State in India

Abstract

Groundwater is the major source of drinking water in rural as well as in urban areas and over 94% of the drinking water demand is met by groundwater. The present work aims at finding the groundwater quality around Nadergul area and hence determining its suitability for drinking and irrigation purposes. This block has semiarid climate and people are mostly dependent on groundwater for irrigation.The groundwater quality of the area needs to be continuously monitored to get the long-term sustainability. In view of this, an attempt has been made to analyze the groundwater quality of the study area to determine the exact level of physico-chemical parameters giving emphasis on its irrigation and domestic suitability. Samples of groundwater  werebrought from the vicinity of MVSR engineering college. MVSR engineering college is located to the  south of the city of Hyderabad ,in a micro water shed of about 900 hectares. 10 samples of groundwater  frompreferably chosen bore wells ,were examined for significantphysico-chemical parameters by adhering tostandard methods of APHA. The study focuses on the distribution of quality of groundwater in aforesaid region. The study was undertaken with the following objectives , to determine groundwater flow in the presence of a dyke and its influence on ground water quality parameters such as Chlorides (mg/l),  Electrical Conductivity, Total dissolved Solids, pH, Alkalinity, hardness,Arsenic,Zinc , manganese etc., and draw various thematic maps to depict the spatial distribution of groundwater quality in the study area. IDW (Inverse Distance Weighted) interpolation technique was employed to synthesise various raster maps that show the spatial distribution of given water quality parameter. Iso-concentration map are made by using ArcGIS software. Iso-concentration maps are necessary for predicting the water quality and to know the concentrations of various water quality elements at variouslocations.After analysis of water quality index(WQI) according to Ramakrishnaiahetal (2009), some samples indicate that water of some locations is not acceptable for direct consumption and is outside the permissible limit. 10 water samples that were collected from bore wells of study area were analysed for different physico-chemical parameters such as pH, electrical conductivity, total alkalinity, total hardness, chloride, BOD, COD, iron, manganese, arsenic, fluoride and total dissolved solids. pH value in the study area found from 7.8 to 8.4. EC ranges from 976-1061 µmhos/cm and total alkalinity between 135 to 378 mg/l. BOD from 3 to 56mg/l. COD from 10 to 186 mg/l. Total hardness ranged from 171 to 432mg/l and Zinc from 2 to 4 mg/l. Arsenic obtained 0.01 mg/l. Manganese varied from 0.02 to 0.1 mg/land chloride from 64 to 205 mg/l. Value of iron 0.01mg/land fluoride from 0.4 to 0.6mg/l while value of TDS ranges from 458 to 522 mg/l. The study reveals that most of the parameters were within the permissible limits. As per the desirable and maximum permissible limit for BOD, COD, fluoride in drinking water, determined by WHO,BIS and ICMR standards groundwater sources are unfit for drinking purposes and irrigation. Due to the lower fluoride level in drinking water several cases of dental problems have appeared in this region. After evaluating the data of this study it is concluded that drinking water of Nadergul is not potable since average water quality index across the sampling stations is above 100 and there is an instant need to take ameliorative steps in this region to prevent the population from adverse health effects.