Water quality surveys and assessments
The quality of water in a potable water supply needs to be monitored to ensure it is of a high enough standard to reduce health risks to an acceptable level in the community.
Content Table
Water Quality Monitoring Programs
The monitoring program employed, will need to be tailored to the specific risks identified in the source water to be treated, for example: a surface water catchment with a large agricultural presence may monitor for pesticides more regularly than a desalinated water supply. Therefore, establishment of an adequate water quality survey program requires:
- an in-depth hazard analysis of the water sources, and risks to water quality
- analysis of any previous source water and treated water data (to check for chemicals/organisms of concern and analyse variability in chemical and organism loads on the treatment plant, and in the treated water)
- assessment of the risks to quality during storage, distribution and transport
- a knowledge of the distribution system to ensure a cross-section of sites is sampled (e.g. dead ends, end of system, start of system etc helping to identify the best case and worst case)
The frequency of which parameters are to be sampled and analysed for is also dependant on both the hazard analysis (the likelihood that a hazard is present) and the risk analysis (the effect that hazard could have if ingested), therefore in a number of water quality monitoring programs bacterial pathogens (that are an indicator of the risk of faecal contamination, e.g. E coli or faecal coliforms) are often sampled more frequently (weekly) than some inorganic parameters (e.g. heavy metals that may be both unlikely to appear and are generally a more chronic health risk that may only be monitored quarterly).
Information on the operational and environmental issues occurring around the time of sampling may also help with interpretation of results (e.g. surface water sampling conducted after a storm event, or increased flows in the pipe system due to a main break or other high demand event). Customer complaints are also an important tool to help ensure water is of adequate quality.
Related Articles
- Water Quality and Purity
- Water Quality
- Waterborne Dieseases
- Drinking Water Quality
- Drinking Water Standards
- Health Impact Assessment
- Wastewater Indicators
- Water Safety Plans: Managing Drinking-water Quality for Public Health
- Water Safety Plans: Resources to Support Implementation
References
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Links
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