All wells that have been flooded or exposed in any other way to contamination require heavy doses of chlorine for disinfection. The procedure for chlorinating a typical private well is as follows:

•  Add approximately one gallon of liquid household bleach (5.25% Calcium Hypochlorite) to the well through a suitable casing vent or tap.
• Surge the well by turning the pump on and off three or four times.
• Flush the lines at each inside and outside outlet until a chlorine odor is noticeable.
• Allow the chlorinated water to remain in the entire system for at least four hours and preferably 24 hours.
• After the waiting period, flush the entire system at all outlets until the chlorinated water has been removed from the system.
• Take a water sample in a sterile sample bottle supplied by the health department and submit the sample for bacteriological examination.

Please call the Environmental and Consumer Health Division at (409) 938-2411 with any questions you might have regarding water well disinfection or sampling.