Baykeeper Update

Helping Avert Harm to the Bay from Nutrient Pollution

Baykeeper recently helped improve new regulations to protect San Francisco Bay from an emerging pollution threat: excess nutrients.

Nutrients are substances such as nitrogen or phosphorus that enter the Bay via treated wastewater discharged into the Bay from the region’s sewage plants. Rain also washes nutrient-rich fertilizers from urban gardens and upstream agricultural lands into the Bay. Excess nutrients can cause certain types of algae to grow, which depletes oxygen needed by fish and other sea life.

In the past, sand and mud washed down from the Sierra Nevada and the Delta into the Bay, making the water cloudy enough to keep the growth of algae in check. Now, less sediment is washing down, and the Bay’s water is getting clearer. Excess algae growth is becoming a bigger threat.

Nutrient pollution impacts different parts of the Bay in different ways, but scientists have already observed increased algae and reduced oxygen in the South Bay, signs of reduced oxygen in Suisun Bay, and toxic algae throughout the Bay. Scientists fear nutrient over-enrichment, primarily from sewage treatment plants, may be tipping the Bay towards more toxic algae blooms and large areas where dissolved oxygen is too low to support fish.

In response to this threat, regulators at the San Francisco Bay Regional Water Quality Control Board recently approved guidelines to address nutrient inputs from the 42 sewage treatment plants that discharge wastewater into the Bay. The regulations will kick off a multi-decade process likely to result in upgrades to many sewage treatment plants, in order to meet the requirements to prevent toxic algal blooms, oxygen depletion, and impacts to fish and wildlife.

As a result of Baykeeper’s input on the new regulations, the Regional Board is requiring sewage agencies to explore options for more use of recycled wastewater for irrigation and industry. This could reduce nutrient pollution in the Bay while also decreasing unnecessary consumption of freshwater. Additionally, Baykeeper’s Staff Scientist Ian Wren has been appointed to the Steering Committee that will shape ongoing studies and future regulations, including determining appropriate levels of funding and any need for additional studies.

Full implementation of a strategy for reducing nutrient pollution in the Bay is likely to take decades. Now is the time to implement a new vision for water management that reduces pollution, reduces the use of imported water, and encourages greater collaboration among agencies. Baykeeper will continue to advocate for a nutrient pollution prevention strategy that can result in dramatic improvements in the Bay’s water quality and more sustainable water management in our region.

Baykeeper's comment letter on the Regional Board's first nutrient-specific permit for the region can be found below.