Drinking water quality is a matter of concern in New Zealand. The quality of many New Zealand water supplies has been unsatisfactory as shown by the grading conducted since 1960 by the former Board of Health. In 1991, a quarter of the supplies surveyed failed to meet the Department of Health's microbiological standards. Since 1992, the Ministry of Health has undertaken a programme to improve water quality management. Hence, the achievement of high quality of drinking water requires the implementation of some form of quality management system (QMS) (e.g. Total Quality Management and its models i.e. ISO 9000 / ISO 14000 Standards, Quality Awards). This thesis examines the managerial practices related to the supply of drinking water in water utilities within the Waikato Region and the role of Total Quality Management (TQM) and its models (i.e. ISO 9000 Series Standards, ISO 14000 Series Standards, and the different Quality Awards like The Deming Prize and the Malcolm Baldrige Award and its New Zealand equivalent the National Business Excellence Award) (Refer to Chapter One, Section 1.6 Definition of Terms Used in Research). The use of QMS is now an established part of management practice in most water utilities in New Zealand, having been introduced since 1995 as part of the reforms to public water supply management. The thesis uses case studies to gain an in-depth understanding of quality management practices in the water utilities, the perceptions of water quality managers in relation to the adoption and adaptation of quality management systems. This is a descriptive and interpretive study of the existing quality systems in water supply organizations of the different Territorial Local Authorities of the Waikato Region. The aim is to unravel the managerial practices as a means of answering the research's four sub-research questions: 1) What perceptions do water utilities managers have about quality management in general and TQM in particular? 2) To what extent are TQM practices actually applied in the water utilities? 3) Is there a relationship between the use of specific TQM procedures/models and water quality? 4) What other quality factors do managers in water utilities identify as crucial for improvement of water quality? This thesis uses methodological triangulation and data triangulation including face-toface interviews, observations and document review. Multiple methods (qualitative analysis, quantitative analysis and cross case analysis) are used to study the problem in order to reveal the different aspects of empirical reality and at the same time validate the research findings (Denzin, 1978). The research revealed that some managers working to achieve the minimal management quality that conforms with the New Zealand Drinking Water Standards, while others were aspiring to a high quality of service and seeking continual improvement in the water quality provided. Some managers were reluctant to change and were still practising old techniques, while others were motivated to adopt total quality management (TQM) teachings and apply for ISO certification. Moreover, the research revealed the input and the role played by the customers (i.e. community receiving the drinking water) requirements which is supported by the TQM literature about the importance of customer satisfaction. In order to determine the extent of application of TQM practices by the Waikato Region TLAs and their adoption, the researcher utilized Lewin' s Change Theory to analyse the data which was assembled. The results shows that 2 water utilities have already passed through the 3 phases of Lewin's Change Theory [i.e. they have adopted change towards the new managerial paradigm (unfreezing, changing, and refreezing)], 3 water utilities are at midway range (i.e. they require more work to fully integrate the new managerial paradigm) and 4 water utilities have not made any significant change to their management systems (i.e. these are the water utilities that have made no effort to change). The results show correlation between the adoption of TQM and its models and the quality of drinking water provided to the community exemplified in their water grading. For example the water utilities who are adopting TQM and some of its models i.e. ISO 9000/14000 Standards and the quality awards, have both high score results in the quantitative analysis results and their water grading is higher showing minimal risk to the community. The study identified other factors of importance in achieving higher drinking water quality as stated by the management teams of the water utilities. These factors are: 1) the size and nature of the community served by the council; 2) the community's willingness or unwillingness to add chemicals to drinking water; 3) TLA budget allocations and restrictions; 4) the Ministry of Health system of visiting water utilities every 5 years to revise their water grading; and 5) training budget constraints in relation to quality training. Finally, the thesis considers how important quality management practices could enhance the New Zealand water industry by discussing the relationship between the application of TQM and asset management planning within water utilities. Enhanced water quality will only result from TQM activity if TQM attitudes and methods are successfully incorporated into the complete set of water utility activities.