1. Introduction The supply of wholesome, safe drinking water remains the highest priority for all drinking water providers. Ensuring that water is mi- crobiologically safe for the consumer is achieved by regular monitoring of water quality in samples taken as water leaves the water treatment works (WTW) and at the customer's tap. In addition, the micro- biological risks presented by the source water and the removal of mi- croorganisms across the water treatment works (WTW) final treated water should be understood. The standard analytical techniques for determining the bacteriological quality of drinking water are culture- based methods. From a regulatory perspective, the primary aim is to monitor for the absence of pathogen indicator organisms such as Escherichia coli, total coliforms, Enterococci and Clostridium using tar- geted growth media. In the European Union regulatory standards are