Asked October 21, 2014, 12:57 PM EDT
New Castle County Delaware
Unfortunately I do not know what the real estate regulations are in Delaware as I am in Pennsylvania. However, if you do a shock chlorination and re-test 7-10 days later and the bacteria is gone, then you likely took care of the problem. If, after re-testing, the bacteria is still present then there is likely a more long-term problem there such as surface water contaminating the well, a nearby leaking septic system, a pasture, a dog kennel, etc. that could be contributing the bacteria to the well. In this case, you would best be served by having some type of permanent treatment installed such as an ultraviolet light to kill the bacteria as it enters the home.