Corrosivity of water for concrete and metal water resources infrastructure with modification of the DIN Method and Langelier Saturation Index of Metcalf and Eddy

Abstract

Corrosion or rust is an endless problem, both in Indonesia and in the world. This is so because corrosion or rust is very detrimental, especially if it occurs in water infrastructure, particularly one built from concrete and metal. Corrosion is a decrease in material quality due to a reaction with the environment. The kinds of losses incurred if corrosion occurs in the infrastructure of water resources include reservoir collapse due to the acceleration of corrosion in the dam, damage to the turbine, and damage to the irrigation gates. This research was conducted to determine level of corrosivity water to water infrastructure built from concrete and metal in 9 (nine) reservoirs. The primary data consist of water quality parameters, determined by sampling the water. The storage and preservation methods of the water samples were done in accordance with Indonesian National Standard Number 6989.57:2008. Water quality was tested by an accredited laboratory. Corrosivity of water for metal and concrete infrastructure was calculated using Metcalf and Eddy formula (2003) and the modification of the DIN 4030 method (2008), respectively. The results of the calculation with Metcalf and Eddy’s LSI (2003) show that the water corrosivity in the 9 (nine) reservoirs had the potential to damage the metal infrastructure, ranging from mild to severe corrosion and lime/crust formation. Based on the modification of the DIN 4030 method (2008), the water in 7 (seven) reservoirs did not have the potential to damage concrete infrastructure, but the water in 2 (two) reservoirs had the potential to damage the concrete infrastructure from mild to moderate level.