8.1 Introduction

The production of safe reticulated drinking water is vital for society. In recent decades, there have been numerous examples throughout the world of poor water quality having an adverse impact on human health. Such episodes are rare in Australia, but the dire consequences of compromised disinfection and blooms of cyanobacteria serve to remind us of the need for drinking water treatment.

Addition of chemicals to make water safe for consumption is widely practised by the water industry and has generally been accepted by the community. However, safeguards must be sufficient to ensure that any residual amount of these chemicals, by-products of their reactivity or minor contaminants in their formulations, do not pose an unacceptable health risk.

Treatment chemicals are added to drinking water mainly to reduce or eliminate the incidence of waterborne disease, for other public health measures, and to improve the aesthetic quality of the water. Any chemical used in, on, or near drinking water sources, or used during the treatment of drinking water should:

• be effective for the desired outcome;

• not present a public health concern;

• not result in the chemical, its by-products or any contaminants exceeding Australian Drinking Water Guidelines values.

This chapter provides guidance on chemicals used during the storage, treatment, and distribution of drinking water and quality assurance procedures.