Because it is difficult to get rid of iron bacteria once they exist in well systems, prevention is the best safeguard against accompanying problems.
For well drillers, prevention means disinfecting everything that goes into the ground with a strong (250 ppm) chlorine solution. Iron bacteria are nourished by carbon and other organics, and it is essential that these are not introduced into any part of the well system during the drilling process. Tools, pumps, pipe, gravel pack material, and even the water used in drilling should be disinfected. Use of a tank that circulates chlorinated water instead of digging a mud pit will help avoid contamination from soil. When the well is completed, it should be purged, shock chlorinated (using 1000 ppm solution), and then pumped.
For owners of new wells in places where iron bacteria have been a problem, the best prevention is to be especially alert for signs of their occurrence. If the well driller and pump installer are scrupulous in keeping the new well "clean," iron bacteria even in such areas can be avoided.
For owners of wells with previous iron bacteria infestation, chlorination is the best way to prevent it from reoccurring. Owners can periodically clean wells by shock chlorination, except using a weaker solution 2 quarts of 5.25% chlorine bleach in 100 gallons of water (or 1.25 qts. of 10% chlorine bleach). Another possibility is to install a chlorination unit, a method generally not adopted unless other problems also exist. Good housekeeping practices can prevent iron bacteria from entering a well:
- Water placed in a well for drilling, repair, or priming of pumps should be disinfected, and should never be taken from a lake or pond.
- The well casing should be watertight, properly capped, and extend a foot or more above ground.
- When pumps, well pipes, and well equipment are repaired, they should not be placed on the ground where they could pick up iron bacteria.
- The well, pump, and plumbing should be disinfected when repaired.
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