The Watts Premier M-2400 POE RO Drinking Water Treatment System was tested at the NSF Drinking Water Treatment Systems Laboratory for removal of the viruses fr and MS2, the bacteria Brevundimonas diminuta, and chemicals aldicarb, benzene, cadmium, carbofuran, cesium, chloroform, dichlorvos, mercury, methomyl, mevinphos, oxamyl, paraquat, sodium fluoroacetate, strontium, and strychnine. The microorganisms used in this study served as surrogates for pathogenic bacteria and viruses that may be introduced into drinking water through accidental or intentional contamination. The target chemical challenge concentration was 1 milligram per liter (mg/L). The target microorganism challenge concentrations were 1x106 colony forming units per 100 milliliters (CFU/100 mL) for B. diminuta, and 1x104 plaque forming units per milliliter (PFU/mL) for the viruses. NSF also separately tested an optional post-membrane activated carbon filter that Watts Premier offers, the Flowmatic MAXVOC FF-975. This filter was only tested with the chemicals not removed to 20 micrograms per liter (mg/L) or lower by the RO membrane. One M-2400 system and one MAXVOC FF-975 carbon filter were tested. Each challenge was 30 minutes in length. The M-2400 removed a minimum of 2.9 log10 of the viruses, and 2.5 log10 of B. diminuta. The M-2400 removed all of the chemicals by 96% or more, except for mercury, which was only removed by 38%. Based on the M-2400 chemical challenge results, the MAXVOC FF-975 filter was challenged with chloroform, dichlorvos, mercury, and methomyl. The MAXVOC FF-975 removed 96% or more of the four chemicals. The M-2400 and MAXVOC FF-975 together removed 99% or more of all chemicals but sodium flouroacetate, whose percent reduction was limited by its high detection limit of 20 mg/L.