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Sydney Water Annual Report 2009
Sustainability indicators: Providing clean, safe drinking water
 
Continued full compliance with the 2004 Australian Drinking Water Guidelines.
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In this section:

 

 
 
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Water quality
Performance: Continued full compliance with the 2004 Australian Drinking Water Guidelines.

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Indicator: The percentage of water tests that meet the 2004 Australian Drinking Water Guidelines (for system performance monitoring for indicator organisms)

Sydney Water measures and reports its performance in maintaining drinking water quality against the requirements of the 2004 Australian Drinking Water Guidelines (ADWG).

The guidelines recommend testing for E. coli (or thermotolerant coliforms) to indicate the presence of faecal contamination. The guidelines require that at least 98% of scheduled samples in each supply system contain no E. coli.

Sydney Water routinely monitors and reports E. coli levels. In 2008–09, all 13 supply systems again complied with the guidelines, with 99.96% of tested samples containing no E. coli. This compares with 99.94% of samples complying in 2007–08.

Percentage of water tests that met the Australian Drinking Water Guidelines for E.coli

Indicator: Compliance with health guideline values as
determined by NSW Health in each water delivery system

Health guideline values cover microbiological characteristics and the presence of inorganic chemicals and pesticides. Sydney supply systems continued to perform to a high standard in 2008–09, with 99.97% of test results meeting the 2004 Australian Drinking Water Guidelines (ADWG) health guideline values.

Nearly 8,000 samples were collected from customer supply systems during the year. Three samples contained E. coli.These detections were investigated in accordance with standard operating procedure and further samples were clear. NSW Health was notified of the results and did not consider the initial detection a risk to public health.

There is no guideline value in the ADWG for Cryptosporidium or Giardia. However, under the guidance of NSW Health and in conjunction with the Sydney Catchment Authority, Sydney Water monitors raw and filtered drinking water for the presence of these parasites at all of its water filtration plants.

On two occasions during 2008–09, one Cryptosporidium oocyst per 100-litre sample was detected in treated water. Further samples were clear. NSW Health confirmed that the level of Cryptosporidium oocysts in the samples posed no risk to public health. No Giardia cysts were detected.

Indicator: Compliance with aesthetic guideline values as determined by NSW Health in each water delivery system

Aesthetic guideline values cover the appearance, taste and odour of water. Sydney Water must ensure that water complies with aesthetic guidelines on pH, true colour, turbidity, aluminium, iron and zinc.

Water supply systems in 2008–09 continued to show a high standard of performance, with 99.18% of tests meeting relevant aesthetic guideline values. This compares with 98.92% in 2007–08.

A summary of the 2008–09 water quality test results for each customer supply system is available at www.sydneywater.com.au/WaterQuality/QuarterlyDrinkingWaterQualityReport/

 

 

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Customer satisfaction with water
Performance: Customer feedback shows satisfaction with
water quality is high.

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Indicator: Average rating of customers satisfied with the overall quality of drinking water supplied by Sydney Water

The Customer Relationship Study is Sydney Water’s primary measure of quality of service. Customers are asked to rate the overall quality of the drinking water that comes out of their taps on a scale ranging from zero (extremely poor) to 10 (excellent).

This is the third year that the study has been carried out. The average rating for drinking water quality in 2008–09 was 8.0. This result is a notable improvement on the 2007–08 rating of 7.7 and shows that satisfaction with water quality is high.

Further research results on Sydney Water’s overall quality of service are available in the Customer satisfaction section of this report.

Average customer rating of the overall quality of drinking water 2006–07 to 2008–09

 

2006–07

2007–08

2008–09

From 0 (extremely poor) to 10 (excellent)

7.7

7.7

8.0