This Technical Information Report (TIR) includes common test methods used to monitor hemodialysis water treatment systems and product water. The TIR identifies numerous contaminants of interest in the care of ESRD patients or that could impact the safe and effective operations of water purifications systems used in the care or treatment of ESRD patients; provides the maximum allowable levels and action levels from various standards (AAMI/ISO) and other references as applicable; describes symptoms that hemodialysis patients might experience with exposure to the contaminant; describes effects of the contaminant on hemodialysis equipment and water treatment systems; lists common test methodologies used for analysis/detection of the contaminant at the laboratory and clinic level; notes test interferences that can be associated with a specific test method.