A self-contained well water system is designed to be interposed between an external well pump and a plumbing system of a building. The system requires an installer or building owner to make only three basic connections for fully-functional operation: a single water inlet connection from the well pump to the well water system, a single water outlet connection from the well water system to a main input line of the building plumbing system, and a single power connection to provide electrical power to the electrical components of the system, and may also distribute power out to the well pump. The remaining components and the connections therebetween are configured and factory-assembled for maximum performance and efficiency.