The City of Ventura struggled with odors from its plant due to extremely high sulfide concentrations in the influent wastewater. As part of the construction of new plant headworks, an odor control system, consisting of a lava rock bioscrubber followed by activated carbon adsorption, was added. The results have been better than expected, with the bioscrubber alone removing 92 to 99 percent of the hydrogen sulfide in the foul air.