Abstract
Water and Sanitation are interrelated. Water is required for the optimal operation of sewerage pipelines, water treatment and wastewater treatment facilities. In the absence of water, it is almost impossible to achieve adequate sanitation. The provision of water and sanitation services is acknowledged as a human right for all, both the destitute and affluent individuals. As a developing country South Africa is experiencing a rapid growth in the multitude of urban dwellers, this rapid growth remarkably overstrains sewer pipelines often leading to clogging, leakage and deformation. Most pipelines are no longer operating in line with design conditions, design parameters and standard operating procedures leaving them susceptible to catastrophic failures. In addition, the absence of rigorous and regular maintenance has resulted in some of the sewer pipelines reaching their ultimate limit state, only seconds away from disaster.
This research reviews the reliability of sewerage pipelines in South Africa, the factors affecting the reliability and the reliability tools that can be utilized to improve sewer pipeline reliability. This is in line with the National Development Plan: A Vision for 2030.
The first section focuses on the evolution of sewerage pipelines and the statutory right to water and sanitation. This section further outlines the water and sanitation services provision (South African context) and briefly presents the National Development Plan. The second section involved the lifecycle of a sewerage pipeline and the factors that affect the reliability. Based on literature the following nine factors were identified as the prominent factors that affect the reliability of sewerage pipelines; design parameters, environmental factors (corrosion), fatigue, third party interference, natural disasters, longitudinal deflection, leakage, buckling and shear failure. In Addition, this section also presented and analysed the following eight reliability tools: FRACAS, DoE, FTA, HAZOP, RBM, QRA, FMEA and PoF. It concludes by identifying the sewer pipeline lifecycle stage at which the application of these reliability tools would yield effective and optimal results thus enhance the sewer pipeline reliability.