Wells require permits. The State of Colorado Water Resources issues well permits. Often when a well is drilled, the people require that the water be tested. Some tests are performed by the State while others are traditionally performed by private Labs.
There are many folks that may have control over one’s ability to have a well, you should always be aware of who has control over the area you desired to drill. Be careful and insure it is allowed. Some of the identies you should inquire with are as follows: County, City, subdivision, Homeowners Associations