Retractable Odor Control Covers Improve Access to Wastewater Tanks at San Francisco Bay Sanitation Plant

The Vallejo Sanitation & Flood Control District, in the San Francisco Bay area, has been engaged in a program to scrub off-gas odors from all aspects of its wastewater treatment plant. Early in the project, the district had covered all of the facilities in its headworks and primary treatment steps to control off-gas. Later, it developed a novel approach for the management and disposal of its biosolids, including designing a specialised hopper for storage of the plant’s dewatered solids and an automated truck-fill process for transportation of the solids to a districtowned landfill – Tubbs Island – again minimising off-gas release. Recently, the wastewater plant has focused on scrubbing off-gas odors from its secondary treatment processes, and specifically its two open aeration basins. To contain these odors, the district opted to use a retractable, structurallysupported geomembrane cover system from Geomembrane Technologies Inc. (GTI), which has not only proved effective for the collection of off-gas, but has also provided an unprecedented level of flexibility and ease-of-access for tank monitoring,
maintenance and repairs.

The Vallejo Sanitation & Flood Control District, in the San Francisco Bay area, has been engaged in a program to scrub off-gas odors from all aspects of its wastewater treatment plant. Early in the project, the district had covered all of the facilities in its headworks and primary treatment steps to control offgas. Later, it developed a novel approach for the management and disposal of its biosolids, including designing a specialised hopper for storage of the plant’s dewatered solids and an automated truckfill process for transportation of the solids to a district-owned landfill – Tubbs Island – again minimising off-gas release. Recently, the wastewater plant has focused on scrubbing off-gas odors from its secondary treatment processes, and specifically its two open aeration basins. To contain these odors, the district opted to use a retractable, structurally-supported geomembrane cover system from Geomembrane Technologies Inc. (GTI), which has not only proved effective for the collection of offgas, but has also provided an unprecedented level of flexibility and ease-of-access for tank monitoring, maintenance and repairs.