Sydney’s water is tested on up to 70 different parameters (characteristics) covering micro-organisms, taste, colour, odour and chemical content.

Sydney Water has reported on a selection of parameters (characteristics) of particular interest to the customer. These have been chosen in consultation with NSW Health.

The Australian Drinking Water Guidelines are jointly set by the National Health and Medical Research Council (NHMRC) and the Agricultural & Research Management Council of Australia & New Zealand (ARMCANZ). They are based on World Health Organisation (WHO) levels that have been adapted to suit local conditions.

The Australian Drinking Water Guidelines are set by the National Health and Medical Research Council (NH&MRC) and the Agricultural & Research Management Council of Australia & New Zealand (ARMCANZ). In 1996 the Council revised the guidelines in consultation with the general community, health bodies, water suppliers and regulators.

The guidelines are continually reviewed and revised by the NHMRC as new information comes to light.

We do not sample at everyone’s tap but we do have representative sample sites in each water delivery system. This includes hundreds of taps across all systems.

The sampling program has been designed to give a clear picture of what the water quality is like at all customers’ taps across the system.

The data is indicative of the quality of water from the catchment to the customer. Sydney’s water is comparable to the best in the world. Sydney Water has in place a strict measurement and reporting process for water quality which is based on an agreement with the NSW Department of Health. In the event that the water is not safe to drink or should an incident such as the Cryptosporidium contamination of 1998 occur, we will act through an agreed protocol with NSW Health and they will advise you of any health issues.

Water quality testing and monitoring takes place at various times and stages of the storage and distribution process to ensure that it is safe and that water quality standards are met.

Samples are taken from customers tap's, at reservoirs, on the outlet of water filtration plants, within the water filtration plants for operational purposes and in the raw water. Depending on the type of water quality characteristic, samples may be taken continuously (on-line), daily, weekly, monthly, quarterly or annually.

The tests are done mainly in Sydney Water labs. The labs are accredited by the National Association of Testing Authorities (NATA) and undergo constant internal, second party and independent audits in relation to all their processes so the public can be assured that the results which are available are verified and accurate. NSW Health reviews these results.

NSW Health has also engaged an independent laboratory to conduct some monitoring for Cryptosporidium and Giardia to help verify Sydney Water’s test results.

Hard water is mostly a measure of the Calcium Carbonate (CaCO₃ ) level in milligrams per litre. Below 60mg/L water is considered soft and above that level it is considered hard. For Sydney’s water the average reading is around 46mg/L so it is considered soft.

The water quality information released to the public has gone through a quality process, which is set up in agreement with the NSW Department of Health. Quality assurance systems are in place at all stages of the various processes of monitoring, analysis, verification and reporting. Both Internal and Independent Audits are carried out regularly on all these processes to ensure the integrity and accuracy of the information being provided.

Sydney Water has conducted significant amounts of work since the 1998 water quality incident. We have:

• increased monitoring of raw water storage at dams
• improved controls on raw water flowing into our water filtration plants
• established a standing panel of water quality experts, along with NSW Health
• improved catchment management
• reviewed all processes within the Water Filtration Plants.

One of the big outcomes of the water quality incident was the establishment of the Sydney Catchment Authority. Its purpose is to protect and enhance the quality of water and catchment management.