When buying a house you may come across a house that uses a private well for water supply instead of public water. There are advantages and disadvantages to a well water system and a public water system so it’s not something you should automatically rule out.
Is Well Water Safe?
Modern well design uses deep drilling down to bedrock to obtain water that is naturally filtered through miles of the ground. There are additional contaminants that can still occur in the water so further testing is required and possibly additional filtration. The State of Maine recommends testing your well water once a year for bacteria and nitrates and every 3 to 5 years for arsenic, fluoride, uranium, radon, lead, and manganese. Public water does water quality testing, but they test the water before it is run through miles of often very old piping to arrive inside your house. The drinking water crisis in Flint Michigan was partially caused by the faulty assumption that public water is tested and safe, but the piping between the water supply and the houses was leaching lead in to the water.
Typically lower operating cost
Control of your individual water supply
Less susceptible to outage due to water main breaks
Periodic testing is easy to forget
System potentially requires filtration system(s)
Pump/tank require eventual replacement
No water when there is a power outage
Older shallow wells susceptible to running dry in a drought