Low-cost apparatus is described for treating an effluent fluid stream from a process tool. In one embodiment, the apparatus comprises an abatement device (12) and a liquid ring pump (14) for at least partially evacuating the abatement device (12). During use, the abatement device (12) converts one or more components of the effluent stream, for example F2 or a PFC, into one or more liquid-soluble a compounds, for example HF, that are less harmful to the environment. The liquid ring pump (14) receives the effluent stream and a liquid, and exhausts a solution of the liquid and the liquid-soluble component of the effluent stream. The liquid ring pump (14) thus operates as both a wet scrubber and an atmospheric vacuum pumping stage.