You may get a new well tested by a private company to expedite getting a Certificate of Occupancy, provided it is a laboratory certified to perform and report the results of bacterial examination of water.  Trained laboratory personnel must actually go out to the home site, collect the sample for analysis and report laboratory test results as negative for bacterial contamination.  While a CO can be released before results are known, Public Health will also collect samples and send them to the State Laboratory of Public Health for analysis of nitrates and inorganic constituents.  Because high levels of nitrates can pose significant health risks for certain populations, it is good practice to wait for these results before using well water to make food or formula for infants and children.
How to Disinfect a Well: