S1.2.1.4 Ensure that the Nature of Use of Use different contractor is pesticides persistent contractor. Contamination that the roof is used by of roof and used to collect contractors. insecticides guttering during drinking-water, by contractor. spraying to Pesticides in and that protect roof water Knowledge of overspraying timbers against following overspraying must be avoided. and other treatment of events. insects, or Obtain a roof timbers, if Water proofing against guarantee from there is contains spiders. the contractor concern about pesticides at that persistent the nature of organochlorine the pesticides more than pesticides will not used, and the 50% of their be used. way in which MAV.2 they were Use first-flush Decontaminate used. diverted or the roof. disconnect Use alternative downpipe, before supply until first rain after decontamination treatment of the is complete. roof. 2 The risk associated with this will depend on location within the country. Preventive measures Checking preventive measures Corrective action Causes What to check that action is needed Event: EXCREMENT AND CHEMICAL CONTAMINANTS CARRIED ONTO ROOF OR INTO GUTTERING cont’d S1.2.1.5 Ensure access to Check the roof Evidence of Eliminate means the roof is made for unauthorised by which access Vandalism/ as difficult as unexpected access having to the roof was sabotage. possible, by objects on it, been gained to gained. removing such and the area the roof. Remove things as ladders. surrounding contaminant the building Inspect the roof source, for objects regularly for disconnect that may make deliberately downpipe and access to the introduced wash down. roof easier. contaminant sources (eg, bags of chemicals). Event: MATERIALS DISSOLVED FROM THE ROOF, FLASHING GUTTERING AND DOWNPIPES BY THE RAINWATER Possible hazards: Heavy metals (lead, copper, chromium, cadmium). Level of risk: Moderate
S1.2.1.4 Contamination of roof and guttering during spraying to protect roof timbers against and other insects, or proofing against spiders. Ensure that the contractor is that the roof is used to collect drinking-water, and that overspraying must be avoided. Obtain a guarantee from the contractor that persistent organochlorine pesticides will not be used. Nature of pesticides used by contractors. Pesticides in water following treatment of roof timbers, if there is concern about the nature of the pesticides used, and the way in which they were used. Use of persistent insecticides by contractor. Knowledge of overspraying events. Water contains pesticides at more than 50% of their MAV.2 Use different contractor. Use first-flush diverted or disconnect downpipe, before first rain after treatment of the roof. Decontaminate the roof. Use alternative supply until decontamination is complete. 2 The risk associated with this will depend on location within the country. Causes Preventive measures Checking preventive measures Corrective action What to check that action is needed Event: EXCREMENT AND CHEMICAL CONTAMINANTS CARRIED ONTO ROOF OR INTO GUTTERING cont’d S1.2.1.5 Vandalism/ sabotage. Ensure access to the roof is made as difficult as possible, by removing such things as ladders. Inspect the roof regularly for deliberately introduced contaminant sources (eg, bags of chemicals). Check the roof for unexpected objects on it, and the area surrounding the building for objects that may make access to the roof easier. Evidence of unauthorised access having been gained to the roof. Eliminate means by which access to the roof was gained. Remove contaminant source, disconnect downpipe and wash down. Event: MATERIALS DISSOLVED FROM THE ROOF, FLASHING GUTTERING AND DOWNPIPES BY THE RAINWATER Possible hazards: Heavy metals (lead, copper, chromium, cadmium). Level of risk: Moderate
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