Implications of groundwater quality to corrosion problem and urban planning in Mekelle area, Northern Ethiopia

Abstract

Surface and groundwater chemistry being an important factor in urban planning and infrastructure development, present paper tries to present the problems of corrosiveness due to groundwater chemistry in Mekelle city. Iron corrosion in distribution systems and engineering structures are common problems in many urban areas. Corrosiveness of groundwater at different localities in Mekelle and its environs has been evaluated on the basis of AAS-UV spectrophotometer-generated hydro-geochemical data. Corrosiveness of water was estimated by using corrosion indices like Larson Index, LI and Aggressive Index, AI and total dissolved solids, total carbonate hardness, chloride and sulphate data were evaluated to estimate aggressiveness of the water samples on iron pipes. Analyses of the results have shown that most of the samples from boreholes and hand dug wells compared to spring samples, are potentially aggressive. The result shows that 66.7% spring, 81.3% shallow hand dug wells and 81% borehole water samples have a Larson index (LI) above 0.5, a threshold of corrosiveness of water. This study highlights the basic characteristics of surface and groundwater chemistry and its potential hazard for corrosion of pipes, and provides a baseline information and awareness to the city planners for urban management.