A pump assembly (214) for an exhaust treatment system is provided that may include a housing (220), a gas flow path (259), a reductant flow path (239) and a pump (224). The housing may include a first inlet (236) configured to receive a reductant from a tank (210), a second inlet (252) configured to receive a gas from a gas compressor (13), and an outlet (262) through which the gas and the reductant exit the housing. The gas flow path may extend between and fluidly communicate with the second inlet and the outlet. The reductant flow path may extend between and fluidly communicate with the first inlet and the outlet. The pump may be at least partially disposed within the housing and may include a motor in a heat transfer relationship with gas flowing through the gas flow path.