Austin Water Integrated Approach to Odor Control: Sewer to Plant Considerations

This paper presents the integrated approach by the City of Austin to address odor concerns in the Greater Walnut Creek Area and its sewershed. The project focused on the identification of the odor sources and their potential impact on the community using dispersion modeling. The project also used sewer process models to comprehend the entire collection system to determine H2S hot spots and to screen sulfide control strategies considering plant impacts. Results showed that the baseline scenario for the Walnut Creek WWTP exceeded the odor threshold set forth. The City is going through an expansion of the Walnut Creek WWTP that incorporates these findings into the design of odor control facilities to mitigate outside impacts. The resulting optimized strategy for the collection system relies on the use of pH adjusters; the WWTP currently uses it in its process thus representing ‘free’ chemical by dosing it upstream for odor control.