Formation of a Practical and Informative Management and Public Communication Tool for Information on Drinking Water Quality
This report was produced for the Urban Water Research Association of Australia, a now discontinued research program.
Report no. UWRAA 143
Information on drinking water quality often involves the collection of a wide range of microbiological and physico-chemical characteristics. This wide range of characteristics makes it difficult to present the information on drinking water quality in a summary form, suitable for:
- Management decision making
- Communicating with the public
Similarly complex economic information has been successfully summarised in the form of an index (e.g. the Consumer Price Index for goods and services, and the All Ordinaries Index for stocks).
This project investigated if it was possible to use an indexing process for the presentation of summary information on drinking water quality. In particular, the project investigated the formation of a practical and informative management and public communication tool for information on drinking water quality.
The project identified and addressed the main issues that impacted upon the formulation of a drinking water index, such as:
- The importance of the microbiological measures of water quality in any proposed index.
- The need for an index that was:
– Specific enough to be able to accommodate local variability, and allow each drinking water authority to ‘create’ an index that best addressed their particular needs and concerns. Such an index had to be able to provide answers to such questions as:
¨ Generally, is drinking water quality better in part A of the system, as opposed to part B?
¨ Generally, is drinking water quality better this year than last year?
¨ Generally, is drinking water quality better this season than last season?
¨ Generally, has drinking water quality improved since change X was implemented
– General enough to be applicable in many different drinking water distribution systems, and allow different drinking waterauthorities to use the same indexing procedures. Such an index had to be able to provide answers to such questions as:
¨ Generally, is drinking water quality better in one system than another.
The project suggests the formation of a:
– A specific index with the following characteristics:
¨ Total of 100 points (based on the relative information value of the various parameters in the index).
¨ Pass/fail value of 50 points.
¨ Microbiological characteristics contributing 60 points to the total score (consisting of parameters specifically selected for the particular system).
¨ A list of parameters suited to the needs of each particular drinking water authority.
– A general index with the same characteristics as the abovementioned specific index, but with a standard set of 6 water quality characteristics (2 microbiological and 4 physico-chemical) which are monitored by most drinking water authorities.
The report discusses the use of the proposed drinking water index in terms of:
– Management decision making
– Communicating with the public.