Flood waters which inundate wells can carry large debris that could loosen well hardware, dislodge well construction materials or distort the casing. Coarse sediment in the flood waters can erode pump components. If the well is not tightly capped, sediment and flood water can enter the well and contaminate it. Wells that are more than 10 years old or less than 50 feet deep are likely to be contaminated, even if there is no apparent damage. Floods may cause some wells to collapse.
After flood waters have receded and the pump and electrical system have dried, care must be taken before restarting wells. Equipment should not be turned on until the wiring system has been checked by a qualified electrician, well contractor, or pump contractor. If the pump’s control box was submerged during the flood, all electrical components must be dry before electrical service can be restored. All pumps and their electrical components can be damaged by sediment and flood water. The pump including the valves and gears needs to be cleaned of silt and sand. If pumps are not cleaned and properly lubricated they can burn out. Assistance should be obtained from a well or pump contractor who can clean, disinfect, repair or maintain different types of pumps before turning on the pump.