Introduction

Abstract

Groundwater is one of the most important renewable resources of the Earth and it occurs in many sites. Water in the form of rainfall and river or stream water penetrates the ground and moves through the pores of soils, rocks, and rock fractures and joints which are permeable enough to transmit water through them. The Earth’s total water resources have been estimated to be of the order of 1.37 × 10⁸ million ha-m. Out of these water resources, about 97.2 % is salt water, available only in the Oceans and only 2.8 % is available as fresh water at any given time on our planet.