If the water supply to the house is a well or spring, consider getting the water tested for common problems.  Many mortgage lenders will require testing for bacteria and other contaminates if the house water source is a well or spring. A sample of the tap water can be lab-tested for bacteria, nitrites, nitrates, E-coli, arsenic, PH and Hardness and many other contaminates.  Results take about 2-4 business days