The Water Should Be Run Until Clean Smelling
After repairing or replacing a well pump, as advised by the New Jersey Department of Health, the well water supply should be sanitized using a strong chlorine solution for a minimum of 6 hours. Once the water supply is sanitized, the chlorinated water should be allowed to soak in the home piping system for an hour.
Then the water should be run until all traces of chlorine are gone.
Running the Water Is Not Required
Well water is not contaminated nor otherwise affected simply by the replacement of an external well water pump. Provided the well pump itself is not submerged within the well, and the well wall structure has not been disturbed, extended running of the water serves no purpose.
It is almost impossible to determine exactly what will and what will not affect a well water supply located deep within the ground. Prudence dictates that any time well maintenance or repair is performed, the water should be thoroughly sanitized and then run until it is clean again.
The cost of sanitizing a well versus the risk of not sanitizing a contaminated well clearly promotes the frequent sanitization and running of well water.