GIS based Site Suitability Analysis for delineation of Wastewater Treatment Plant potential zones in Upper Ponnaiyar Watershed, South India

The management of water resources is a major challenge for most of the dry land areas, as the demand for water are increasing and the quality are being compromised due to a number of natural and economic factors. Rural, periurban and urban should focus in future for decentralised wastewater treatment systems. The cluster of decentralised treatment system provide best management of wastewater in summer and winter seasons. The investment, operation and maintenance of decentralised treatment plants will provide a higher level of environment. In the selected study area Upper Ponnaiyar, water pollution issue has gotten worse recently, in order to solve the water pollution issue, building a wastewater treatment plant is a good way to treat polluted water. If the proper location for the treatment plant is not selected, then it may lead to soil degradation and groundwater pollution. This study was conducted by using GIS techniques for selecting suitable wastewater treatment plant zonation. There are seven parameters considered in the analysis consists of land use/land cover, elevation, road proximity, a slope of the ground, drainage density, geology, and soil. The weighted index overlay analyses of the final map with final weighted factor map were integrated and produced the final suitable wastewater treatment plant site map using ArcGIS Spatial Analyst tools. As a result, 73.88 km2 (6.90%), 359.55 km2 (33.59%), 441.08 km2 (41.21%), 180.71 km2 (16.88%), 15.05 km2 (1.41%) of the total study area was found to be unsuitable, low suitable, moderate suitable, high suitable and very high suitable respectively. The area of very high suitable is preferable for wastewater treatment plant sites, because of their minimum effect on the environment, public health and cost effective than other parts of the study area. Therefore, the study will help the concerned authorities to formulate their development strategies according to the selected suitable wastewater treatment plant site available to the area.