The present invention is an apparatus and method for controlling pressure, pumping a vacuum and providing abatement for a plurality of vacuum processing chambers. The system may be used in semiconductor manufacture. Multiple vacuum processing chambers are exhausted by turbo pumps into a common abatement chamber, which is maintained at sub-atmospheric pressure by a backing pump. Pressure in the processing chambers is independently controlled. The internal volume of the abatement device provides a buffer that reduces the effect of pressure changes in one processing chamber affecting pressure in the other chambers.