Delta Diablo is participating as a key member of the Bay Area Biosolids Coalition (Coalition), which is a regional collaboration between San Francisco Bay Area wastewater agencies that are working to develop sub-regional projects with a primary focus on beneficial use of biosolids. In support of its mission to “Develop a Diverse and Robust Portfolio of Beneficial Biosolids Resource Recovery Projects for the San Francisco Bay Area,” the Coalition has established the following specific objectives:
- Assist agencies by evaluating potential biosolids end-use options
- Develop partnerships with academia to advance key biosolids research activities
- Serve as a clearinghouse for cutting-edge technologies
- Develop a strategy for legislative advocacy to support development and implementation of sustainable biosolids management options
- Expand community outreach and education regarding the value of biosolids products
The wastewater treatment process removes solids and organics from municipal wastewater and produces a stabilized, nutrient-rich byproduct called “biosolids.” Wastewater agencies are required to ensure that the quality of the biosolids produced meets regulatory requirements set forth by the U.S. Environmental Protection Agency prior to beneficially using this valuable resource. In the Bay Area, the majority of biosolids are beneficially used as alternative daily cover at local landfills (i.e., for vector and odor control in lieu of soil importation) or as a soil amendment via land application at crop sites. However, the long-term viability of landfill alternative daily cover is declining as the state of California continues to drive organic materials out of landfills through legislative actions (Assembly Bill 32, Senate Bill 1383) to reduce greenhouse gas emissions. In contrast, land application represents an excellent long-term biosolids management option, because it restores soil health and boosts crop production by returning valuable nutrients (nitrogen, phosphorus) and organics to the soil while increasing soil water retention capacity.
This shifting environment also creates opportunities for innovative approaches and public-private partnerships to help meet future challenges. In parallel, the state of California has created numerous programs to incentivize renewable energy and low-carbon fuel production. Wastewater agencies will play a major role in managing organics diverted from landfills by receiving and “digesting” these materials to produce biogas and renewable energy in the form of electricity and transportation fuel. The continued transformation of wastewater treatment plants into “resource recovery facilities” is anticipated to increase biosolids production on a regional level in the years ahead.
Given these drivers, the Coalition is focused on supporting the development of technologies and facilities that will harness the intrinsic value of biosolids via energy recovery and/or fertilizer production. Several Coalition member agencies are evaluating emerging technologies for potential application on a sub-regional level.