The purpose of this guidance manual is solely to provide technical information on applying the Toolbox of Cryptosporidium treatment and management strategies that are part of the Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR). This guidance is not a substitute for applicable legal requirements, nor is it a regulation itself. Thus, it does not impose legally-binding requirements on any party, including EPA, states, or the regulated community. Interested parties are free to raise questions and objections to the guidance and the appropriateness of using it in a particular situation. Although this manual covers many aspects of implementing Toolbox options, the guidance presented here may not be appropriate for all situations, and alternative approaches may provide satisfactory performance. The mention of trade names or commercial products does not constitute endorsement or recommendation for use.