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? Organic matter and bird faecal contamination being washed into the tank from roof and gutters High Yes Screen on tank inlet Self-draining first flush device Cleaning of screen every 2 weeks Undertake monthly E. coli testing Disinfect water (chlorination or UV) or provide bottle water or advise guests to boil water. Within 1 month Contaminants from neighbouring property and roads High Yes Screen on tank inlet Self-draining first flush device Cleaning of screen every 2 weeks Undertake monthly E. coli testing Within 1 month Build-up of sludge in tank, dirt in inlet strainers and/or insect screens Medium No Self-draining first flush device Cleaning of screen every 2 weeks Undertake monthly E. coli testing Disinfect water (chlorination or UV) or provide bottle water or advise guests to boil water. Roof materials (e.g. lead sheeting; peeling paint) Medium Yes Roofing materials unknown Yearly chemical testing
Contamination from insects, birds and animals entering tank with rainwater from the roof High Yes Screens on tank inlet Routine cleaning Undertake monthly E. coli testing Within 1 month Contamination from insects, birds and animals entering directly from the roof of the tank Medium Yes Roof integrity Routine check of tank Undertake monthly E. coli testing Disinfect water (chlorination or UV) or provide bottle water or advise guests to boil water. 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 Run taps for a several minutes after they have been left standing Yearly chemical testing
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. 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. paint, lead flashing, 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