Managing per- and polyfluoroalkyl substances in the San Francisco Bay

Author

Wendy KwongFollow

Date of Graduation

Spring 5-21-2021

Document Access

Restricted Project/Capstone - USF access only

Degree Name

Master of Science in Environmental Management (MSEM)

College/School

College of Arts and Sciences

Department/Program

Environmental Management

First Advisor

Allison Luengen, Ph.D.

Abstract

Per- and polyfluoroalkyl substances (PFASs) have been used in a wide-range of consumer products and industrial applications since the 1940s. As a result, PFASs have been found in San Francisco Bay (SF Bay) water, biota and sediment samples. Information regarding the concentration trends, sources, fate and transport, and toxicological effects are used to support stricter regulations in the SF Bay. The potential area of concern is in the Lower South Bay where PFASs can reach concentrations as high as 75.6 ng/L for perfluorooctanoic acid. Based on the PFAS concentration data available from sources of the SF Bay, an estimated mass balance was calculated and found that the highest contribution of PFASs comes from stormwater runoff from watersheds and PFAS-contaminated sites. Since the SF Bay wastewater treatment plants (WWTPs) typically employ secondary treatment as the last treatment step, WWTPs need to upgrade to activated carbon or titanium dioxide-based photocatalysts for photo degradation to remove PFAS; cost of technology and regeneration is still high and 100% removal/ effectiveness is not certain. Future regulations from the United States Environmental Agency (USEPA) and State of California State Water Board Quality Control Board (State Water Board) will broaden their regulatory oversight on additional PFASs but more research is needed on the toxicological effects of other PFAS compounds that have been used to replace long-chain PFASs with established toxicological effects. USEPA and State Water Board should expand regulations to include ecological thresholds and fish consumption recommendations for the SF Bay.

Recommended Citation

Kwong, Wendy, "Managing per- and polyfluoroalkyl substances in the San Francisco Bay" (2021). Master's Projects and Capstones. 1206.
https://repository.usfca.edu/capstone/1206