Publications
Penn State Cooperative's "Guide to Private Water Systems in PA" (PDF) provides information for private water systems in Pennsylvania about the proper construction and maintenance of private wells, springs and cisterns. It includes information about estimating water needs, protecting your water system, potential sources of pollution, common contaminants, and treatment information.
EPA's "Drinking Water from Household Wells" (PDF) explains how ground water can be polluted and what you can do about it.