3.1 Risk Assessment Step 1 Hazard Step 2 Risk Rank Step 3 Step 4 How is this control monitored? Step 5 If not controlled what could be done to improve safety? Step 6 Timeframe for action Hazard Controlled? What is the control, if any? Bore water contaminated by surface activities High Yes UV system Membrane system Routine inspection of the water treatment system 1.Undertake monthly E. coli testing. 2. Sign non potable water Within 1 month Contamination from tank Medium Yes Screen on tank inlet Screens cleaned every 2 weeks. Tank drained every 2 years Sign Posted non potable water. Disinfection Monthly Low pH of water corroding plumbing fittings when the taps haven’t been used so water sits in pipes Low No Run taps before use of water Run taps before use of water has been standing in pipes for a while Contamination from insects, birds and animals entering directly from the roof of the tank Low Yes Roof integrity Cleaning of gutters. Clearing overhanging vegetation Ensure cover on tank is sealed Monthly
Corrosion of metal plumbing fittings by soft water e.g. copper from pipes resulting in blue water Low Yes Visual inspection of water colour Good water turnover Groundwater contamination from on-site system Medium Yes Regular maintenance and yearly inspection of system Location of on-site system Membrane treatment UV treatment Regular monthly inspection Undertake monthly E. coli testing. Within 1 month
APPENDIX A – Common sources of contamination (hazards) and suggested control measures Component Potential source of contamination Control measures Water Source Rain water Roof and gutters (e.g. build-up of leaves, dirt and animal droppings) • First flush device • Regular cleaning of roof and gutters • Removal of overhanging branches • Regular inspections • Water treatment (disinfection) Rain water Roof material (e.g. lead-based paint, lead flashing, bitumen-containing products, treated timber, peeling paint) • Water not collected from roofs coated or painted with substances that may leach hazardous materials • Remove or treat lead flashing • Seal any exposed treated timber Surface water (dams, creeks and rivers) Surrounding land use (e.g. farming, urban areas, industrial sites and sewage discharges) • Protect surface water source against livestock, septic tanks/sewage overflows and chemical spills • Water treatment Surface water (dams, creeks and rivers) Animal and human activities • Fence water storage or off-take area • Don’t permit swimming or public access in off-take area • Water treatment Groundwater (bore, well, spring) Surface water seepage • Raise bore heads above ground level and mound up ground around bore head • Ensure bore covers and casing are intact • Regular inspections Groundwater (bore, well, spring) Sub-surface contamination (e.g. from industry, farming, landfill, sewage) • Extract groundwater from places where sub-surface contaminants are unlikely • Test the water for chemicals and treat if necessary • Groundwater source is at least 20 metres from any wastewater disposal systems • Water treatment (disinfection) Water Storage Insect, birds and animals in system Screen all inlets and outlets to the tank • Regular inspections of tank, roof and gutters Build-up of sludge in tank, dirt in inlet strainers or insect screens Regular inspection, cleaning and maintenance program