Springs are particularly susceptible to bacterial contamination since they are generally located in surface water drainageways. A properly protected spring is developed underground and the water channeled to a sealed spring box. At no time should the water be open to the air at the surface. Any time work is performed on the plumbing or pump, the entire water system should be disinfected with chlorine, as described below. Simply pulling the pump out of the well, setting it on the grass to work on it, and returning it to the well is enough to contaminate the water supply with bacteria.
Boiling water is an extremely effective means of disinfection.
Boiling your water continuously for 15 minutes will kill all bacteria. You could also purchase bottled water or use water from another source known to be safe for drinking and cooking. Mix bleach in water thoroughly and let stand for 30 minutes before drinking. The Virginia Department of Health recommends cleaning and sanitizing a contaminated well or spring, and the entire plumbing system, by shock chlorination. This treatment introduces high levels of chlorine in the water.