The City of San Leandro Water Pollution Control Plant has a unique opportunity: an underutilized water storage basin right next to the San Francisco Bay. While this might not sound like much, in 2017, we realized this would be a perfect place to install a Treatment Wetland - a biologically based treatment process that cleans contaminants normal plant process can't, provides wildlife habitat and helps protect against rising sea levels.
In 2018, the San Francisco Bay Restoration Authority awarded San Leandro a $540,000 grant to pursue this vision in their first round of funding through the Measure AA grant program. This enables the City to design and permit the conversion of this 4.3-acre our storage basin into a multi-benefit treatment wetland.
The City hopes to break ground on the project in 2022. This will cost-effectively modernize the plant to meet future water quality regulations, enhance habitat and provide a resource to the community.
What is the Project?
For decades, scientists have recognized San Francisco Bay as a nutrient-enriched estuary, largely due to heavy inputs of nitrogen from the 40 wastewater treatment plants that discharge over 400 million gallons of treated effluent to the Bay every day. Historically, the Bay has shown resistance to symptoms of nutrient over-enrichment because of its high turbidity, strong tidal mixing, and phytoplankton-eating clams. However, recent studies suggest the need to reduce nitrogen loading to protect the Bay to prevent potential effects of nutrient over-enrichment such as toxin-producing algal blooms. This project will not only reduce pollution to the Bay but also improve habitat and help demonstrate whether nature-based treatment strategies can cost-effectively rehabilitate damaged shorelines areas.
This project involves utilizing an underutilized wastewater storage basin and converting it to a treatment wetland. Current estimates indicate 10-20% of the City's treated effluent can be 'polished' in the pond, prior to direct discharge to the Bay. Using techniques developed by UC Berkeley researchers, the City hopes to nearly eliminate nitrogen and phosphorus (which are "nutrients" that can cause algae blooms and other problems in the Bay) and other contaminants from this portion of its wastewater stream.
San Leandro's Water Pollution Control Plant, built in 1939, is one of the oldest East Bay wastewater treatment facilities and 82% of the city's wastewater infrastructure is exposed to flooding from just 16 inches of sea level rise. Sensitive industrial sites and ecological resources along the City's shoreline also face increasing flood risk over the coming decades. This project most closely focuses on the creation of a multi-benefit wastewater treatment wetland. Yet an additional objective is to develop a community-based vision for how the City interacts with and utilizes its bay front spaces.