Wastewater sludge management for Umgeni water.

Abstract

ABSTRACT Umgeni Water is a state-owned bulk water service provider for water supply and sanitation services to water services authority in its operational area. It is constituted in accordance with the Water Services Act (Act 108 of 1997) and the Public Finance Management Act (Act 1 of 1999), The area of coverage is 21 155 square kilometres and serving 6 million people (1.64 million households) over six Water Services Authorities. Sludge management is an important area of concern across wastewater treatment Plants at Umgeni Water. Inability to remove the sludge in the treatment plants affects the operation negatively resulting in poor performance in some treatment plants. In addition to maintaining treatment efficiency, proper sludge management is important for mitigating pathogen levels and providing opportunities for safe beneficial reuse of sludge. Sludge is characterized with respect to quantities generated (accumulation rates) and quality (helminths and heavy metals content). A review is to be conducted of appropriate sludge treatment technologies including sludge drying beds, alkaline stabilization, anaerobic digestion, and composting. These options to be valuated based on a set of selected criteria. Sludge guidelines regulate sludge disposal options as a result of the type of treatment regime, pathogen removal, and metals substance. Also disposal selections for sludge involves some form of recycling of the product, through direct land application, stabilization, composting, or pelletizing (Bloetscher, 1999). A quantitative approach was used to explore the different sludge management strategies implemented at Umgeni Water and comparing to best practice employed by other Water Authorities. Creswell (2014), defines quantitative research as a method of understanding what factors or variables impact an outcome of the research. This is done through researchers advancing a theory to test, and they will incorporating significant analyses of the literature to identify research questions needing answers. Questionnaires were sent out to targeted sample covering the entire population of employees working on the wastewater treatment plants. This research aimed to compare traditional sludge management options with current global trends focussing on three main areas namely, sludge beneficiation , compliance to environmental regulations and cost effectiveness. Recommendations for integrated approach in process design at Umgeni Water which will allow the Organization to implement sludge beneficiation in all their wastewater treatment plants.