The most important preventive measure is to make sure you do enough monitoring to give you all the information you need about source water quality. (S2.2.1.) (References in parentheses are to the Risk Information Table.) Risk Information Table Reliable information about water quality is essential for the proper management of a water supply. Knowledgeable and skilled staff are also essential for minimising the public health risks associated with water supplies. Please read the staff training (Guide G1) and the monitoring guides (Guide G2). While we haven’t pointed out every detail of how these documents are linked with the present document, the links are many and are important. Abbreviations: DWSNZ Drinking-water Standards for New Zealand; MAV Maximum acceptable value – – – see DWSNZ:2000 Causes Preventive measures Checking preventive measures Corrective action What to check Signs that action is needed Event: NOT ENOUGH WATER Hazards: Low pressure in the water supply system may allow entry of germs and chemical determinands; hazards associated with poor hygiene Level of risk: High S2.1.1 Groundwater Constant Unsatisfactory Choose alternative discharge results for the or additional source. Source Obtain data to aquifer test expected and establish annual Consider options for data. predicted long are variation in water management of term demand. unknown quality and Step drawdown demand. quantity. aquifer test Sustainable Suggested tests data. supply for (quantity): meteorological Specific conditions and Constant capacity test demands on discharge summary. resource from Step other users. drawdown Specific capacity Surface water 5 year low flow data. Obtain data to establish annual Mean annual variation in water rainfall in quality and catchment. quantity. Results of Suggested data probabilistic (quantity): analysis. river flow catchment rainfall probabilistic analysis to determine likelihood of low and supply shortfalls given alternative demand patterns
The most important preventive measure is to make sure you do enough monitoring to give you all the information you need about source water quality. (S2.2.1.) (References in parentheses are to the Risk Information Table.) Risk Information Table Reliable information about water quality is essential for the proper management of a water supply. Knowledgeable and skilled staff are also essential for minimising the public health risks associated with water supplies. Please read the staff training (Guide G1) and the monitoring guides (Guide G2). While we haven’t pointed out every detail of how these documents are linked with the present document, the links are many and are important. Abbreviations: DWSNZ – Drinking-water Standards for New Zealand; MAV – Maximum acceptable value – see DWSNZ:2000 Causes Preventive measures Checking preventive measures Corrective action What to check Signs that action is needed Event: NOT ENOUGH WATER Hazards: Low pressure in the water supply system may allow entry of germs and chemical determinands; hazards associated with poor hygiene Level of risk: High S2.1.1 Source are unknown Groundwater Obtain data to establish annual variation in water quality and quantity. Suggested tests (quantity): Constant discharge Step drawdown Specific capacity Constant discharge aquifer test data. Step drawdown aquifer test data. Specific capacity test summary. Unsatisfactory results for the expected and predicted long term demand. Sustainable supply for meteorological conditions and demands on resource from other users. Choose alternative or additional source. Consider options for management of demand. Surface water Obtain data to establish annual variation in water quality and quantity. Suggested data (quantity): river flow catchment rainfall probabilistic analysis to determine likelihood of low and supply shortfalls given alternative demand patterns 5 year low flow data. Mean annual rainfall in catchment. Results of probabilistic analysis.
new-supplies-feb14-v2.docx