A retail public utility is not required to secure a certificate of public convenience and necessity for:
(1) an extension into territory contiguous to that already served by it, if the point of ultimate use is within one-quarter mile of the boundary of the certificated area, and not receiving similar service from another retail public utility and not within the area of public convenience and necessity of another retail public utility; or
(2) an extension within or to territory already served by it or to be served by it under a certificate of public convenience and necessity.