Cootamundra
Indicator: Drinking Water Quality
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What the results tell us for Cootamundra
The Cootamundra drinking water supply is of excellent and consistent quality.
Quality of the water supplied
Cootamundra and the surrounding communities are supplied through Goldenfields Water County Council. The supply is sourced from the Murrumbidgee River and treated at the Jugiong water treatment plant. This plant has full treatment facilities and uses chlorine disinfection for the supply.
A total of 239 samples were assessed for E. coli, and one sample showed the presence of one organism in December 2006. This indicates a consistently high quality supply.
Forty-four samples were assessed for inorganic components.
Twelve samples were slightly above the recommended pH range of pH 6.5-8.5, however the highest was only pH 8.7, which is of no significance. No other inorganic components were above the Guideline values, apart from single samples analysed for sodium and hardness, again slightly above the guidelines.
About the data
Drinking water quality is monitored as part of the NSW Drinking Water Monitoring Program and detailed results can be accessed through the website http://www3.health.nsw.gov.au/waterqual/samples/register.cfm.
This report on drinking water quality for 2004-2008 is prepared from examination of this data, to illustrate the quality aspects of the water supplied for domestic consumption in the Shire. The Shire uses both public and private water supplies, but only those supplies recorded on the health database are available for comment in this report.
Interpreting the data
The results included in this report are from 1 January 2005 to the time of writing in mid-November 2008. In 2004 the National Health and Medical Research Council introduced the Australian Drinking Water guidelines, which provide the basis for quality assessment. These guidelines have not included total coliforms as a measure of water quality for health purposes, as the organisms are widely present in soil and untreated water and also grow in water pipes. For these reasons a total coliform count does not reflect the content of pathogenic organisms. In contrast, monitoring for Escherichia coli is particularly informative, since this organism occurs in large numbers in faeces and hence is an effective indicator of faecal contamination. It is killed by standard drinking water treatment and therefore should not occur in domestic supplies. The Drinking Water Guideline value is zero organisms per 100ml sample and any detected organisms present in the water therefore exceed the guideline and should result in an increase in the disinfection of the supply.
This remedial action should be taken until the E. coli count returns to zero.
While there are many other pathogens present in faecal contamination of water, monitoring of E. coli has been shown to be an effective and straightforward method for public health. Where the data from a water supply for this period show E .coli present, comment has been made for each water supply reported.
Concentrations of inorganic components of water supplies do not have such a sharp impact on health as faecal contamination. The guideline values reflect safe concentrations for lifetime exposure and minor exceedences, which briefly occur, are of negligible risk to public health. Inorganic constituents become a risk to public health when they consistently exceed the guideline values, with the risk increasing with the concentration in the supply. Where these have occurred, comment has been made in the appropriate section of the report. Unless there is accidental contamination of the supply, it is unlikely that any substantial variations in concentration of inorganic components will occur in any year.
Continuing concentrations that significantly exceed the guideline values require investigation and rectification.
The information assessed in this report is available on the NSW Health Water Database and uses the current National Health and Medical Research Council Drinking Water Guidelines as the reference for the analytical comparisons.
References
NSW Department of Health (2008) Drinking water database http://www3.health.nsw.gov.au/waterqual/samples/register.cfm.
NH&MRC and NRMMC (2004) Australian drinking water guidelines. National water quality management strategy. http://www.nhmrc.gov.au/publications/synopses/eh19syn.htm
