S1.2.4.1 Disconnect Conductivity. Chemical Repeat cleaning downpipe into contaminants procedure until Volcanic Fluoride, tank as soon as still present at analytical eruption results arsenic, possible results for water in ash fall metals eruption. greater than demonstrate (pyroclastic suspected of 50% of their that fall). Use conductivity having MAV. contaminants test to determine elevated are present at whether tank Conductivity concentrations water is fit to of the water is less than 50% of drink. 5–10 mS/m their MAV. higher than If tank water is not normal. fit to drink, empty and clean out tank Tank and roof when all ash falls not cleaned have ceased. sufficiently following ash roof, fall to ensure guttering and contaminants downpipe. are removed from the Event: NOT ENOUGH WATER Possible hazards: Hazards associated with poor hygiene. Level of risk: High S1.2.5.1 Ensure tank size Water level in Water runs out New tank. is adequate. (Use tank. frequently. Lack of rainfall New or information about combined with Rate of water Water levels additional annual rainfall insufficient use. low. source. levels and number storage, Regular Evidence of Repair tank of people using excessive use, (monthly) water leaking and/or supply to leak in tank, or inspection of from tank. guttering. determine size of breach in tank and tank required.) Start water guttering. guttering. conservation Ensure strength of measures. guttering is adequate for wind and snowfall conditions. Establish an inspection programme to check guttering and tank. Conservation of water. 2 The risk associated with this will depend on location within the country. Contingency If an event happens despite preventive and corrective actions you have taken, you may need to consult with the Medical Officer of Health to assess how serious a problem is.
S1.2.4.1 Volcanic eruption results in ash fall (pyroclastic fall). Disconnect downpipe into tank as soon as possible eruption. Use conductivity test to determine whether tank water is fit to drink. If tank water is not fit to drink, empty and clean out tank when all ash falls have ceased. roof, guttering and downpipe. Conductivity. Fluoride, arsenic, metals suspected of having elevated Chemical contaminants still present at greater than 50% of their MAV. Conductivity of the water is 5–10 mS/m higher than normal. Tank and roof not cleaned sufficiently following ash fall to ensure contaminants are removed from the Repeat cleaning procedure until analytical results for water demonstrate that contaminants are present at concentrations less than 50% of their MAV. Event: NOT ENOUGH WATER Possible hazards: Hazards associated with poor hygiene. Level of risk: High S1.2.5.1 Lack of rainfall combined with insufficient storage, excessive use, leak in tank, or breach in guttering. Ensure tank size is adequate. (Use information about annual rainfall levels and number of people using supply to determine size of tank required.) Ensure strength of guttering is adequate for wind and snowfall conditions. Establish an inspection programme to check guttering and tank. Conservation of water. Water level in tank. Rate of water use. Regular (monthly) inspection of tank and guttering. Water runs out frequently. Water levels low. Evidence of water leaking from tank. New tank. New or additional source. Repair tank and/or guttering. Start water conservation measures. 2 The risk associated with this will depend on location within the country. Contingency If an event happens despite preventive and corrective actions you have taken, you may need to consult with the Medical Officer of Health to assess how serious a problem is.