This document is one of several technical documents prepared in support of the Ground Water Rule(GWR). The document describes treatment technologies and best management practices (BMPs) that ground water systems can consider as corrective actions or safeguards to reduce or eliminate microbial risks. The document also presents the estimated costs associated with their installation, implementation, and operation. The United States Environmental Protection Agency (EPA) has the responsibility to develop a ground water rule which not only specifies the appropriate use of disinfection but, just as important, also addresses other components of ground water systems to assure protection of public health.