A dry gas mechanical seal system (200) configured to inhibit the emission of process gas. The mechanical seal system having tandem first and second stage seals, and a single separation gas supply subsystem configured to direct a supply of separation gas from an inlet (250) through interfacing portions (260, 262) of the first stage seal into a process cavity (206) and from the inlet through the interfacing portions (268, 270) of the second stage seal and out through an outlet (280) to the atmosphere, thereby inhibiting the emission of process gas between a compressor housing (204) and a rotating compressor shaft (202).