Cisterns and hauled water storage tanks should be thoroughly cleaned periodically. How often this is done is going to be dependent on the area in which you live. Because cisterns collect rainwater off of the roof they are subject to varying amounts of potential contamination. In areas where there are large trees overhanging the roof area, or in areas where there is a lot of industrial activity, cistern cleaning should be performed more often. Cisterns in these types of areas should be cleaned every three to five years, but they may be cleaned more often if there is a desire or a need to do so. Hauled water storage tank systems that use exclusively hauled water will not require cleaning nearly as often as cisterns if care is taken when re-filling occurs. Ohio Administrative Code 3701-28-12 (N) describes the startup, operation and disinfection of cisterns and hauled water storage tanks.
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