D2.2.1.4 Standby pump with auto Pumps. Pump stops. Re-route start. water from Failure of Pressure. Customer other zones if network Obtain generator backup. complaints. possible. pumps Preventive maintenance quality. Pressure pumping to Start programme for pumps. drops. high zones preventive E. coli or or reservoirs maintenance coliforms (see Guide programme. detected in P10). 100 ml sample. D2.2.1.5 Monitor bore Bore flow. Bore pumps Identify performance either stop. reasons for Failure of Pressure. directly or using an bore pump bore pumps Reduced observation bore. failure, and (for systems flow from quality. rectify. with bores). Preventive maintenance bores. programme for bore Reduced pumps and planed preventive pressure in programme for overhaul maintenance bore-fed of pumps (see Guide P10). programme. reticulation Monitor flow from bore. zone. Monitor reticulation E. coli or system pressure. coliforms detected in 100 ml water sample. 2 This event may lead to discolouration of water and the release of bacteria that were previously protected by the sediment and deposits in the pipes. Preventive measures Checking preventive measures Corrective action Causes What to check Signs that action is needed Event: RE-SUSPENSION OF SEDIMENT OR BIOFILM WITHIN THE MAINS BY PRESSURE FLUCTUATIONS Possible hazards: Germs; chemical determinands. Level of risk: Low–moderate D2.2.2.1 See Guide D2.3 Event D2.3.2. – Sediment or Although D2.3.2 deals with re-suspension of material after repair of a mains break or biofilm attachment of a fitting, the net effect and the risks are the same as re-suspension of allowed to material already in the mains. develop. D2.2.2.2 See D2.3 Event D2.3.2. – Significant Although D2.3.2 deals with re-suspension of material after repair of a mains break or fluctuations attachment of a fitting, the net effect and the risks are the same as re-suspension of in material already in the mains. reticulation pressure. Contingency Plans
D2.2.1.4 Failure of network pumps pumping to high zones or reservoirs (see Guide P10). Standby pump with auto start. Obtain generator backup. Preventive maintenance programme for pumps. Pumps. Pressure. quality. Pump stops. Customer complaints. Pressure drops. E. coli or coliforms detected in 100 ml sample. Re-route water from other zones if possible. Start preventive maintenance programme. D2.2.1.5 Failure of bore pumps (for systems with bores). Monitor bore performance either directly or using an observation bore. Preventive maintenance programme for bore pumps and planed programme for overhaul of pumps (see Guide P10). Monitor flow from bore. Monitor reticulation system pressure. Bore flow. Pressure. quality. Bore pumps stop. Reduced flow from bores. Reduced pressure in bore-fed reticulation zone. E. coli or coliforms detected in 100 ml water sample. Identify reasons for bore pump failure, and rectify. preventive maintenance programme. 2 This event may lead to discolouration of water and the release of bacteria that were previously protected by the sediment and deposits in the pipes. Causes Preventive measures Checking preventive measures Corrective action What to check Signs that action is needed Event: RE-SUSPENSION OF SEDIMENT OR BIOFILM WITHIN THE MAINS BY PRESSURE FLUCTUATIONS Possible hazards: Germs; chemical determinands. Level of risk: Low–moderate D2.2.2.1 Sediment or biofilm allowed to develop. See Guide D2.3 – Event D2.3.2. Although D2.3.2 deals with re-suspension of material after repair of a mains break or attachment of a fitting, the net effect and the risks are the same as re-suspension of material already in the mains. D2.2.2.2 Significant fluctuations in reticulation pressure. See D2.3 – Event D2.3.2. Although D2.3.2 deals with re-suspension of material after repair of a mains break or attachment of a fitting, the net effect and the risks are the same as re-suspension of material already in the mains. Contingency Plans
distribution-system-pressure-feb14-v2.docx