Remote Sensing of Stormwater and Wastewater Plumes in Southern California

EarthzineDEVELOP Virtual Poster Session, Original

Figure showing sea surface temperature (å¡C) with ~26-degree isotherm (dash line) on Oct. 27, 2012. Image Credit: NOAA/NCEP/EMC/MMAB/RTOFS.
Sea surface temperature from Sept. 23, 2012, derived from Level 1B Terra ASTER at-sensor radiance data offshore the Santa Ana River mouth in Southern California. This shows a cold wastewater plume signal from the Orange County Sanitation District outfall diversion and repair event, flowing mostly longshore, with a secondary cross-shore lobe. Image Credit: DEVELOP JPL Team.

Sea surface temperature from Sept. 23, 2012, derived from Level 1B Terra ASTER at-sensor radiance data offshore the Santa Ana River mouth in Southern California. This shows a cold wastewater plume signal from the Orange County Sanitation District outfall diversion and repair event, flowing mostly longshore, with a secondary cross-shore lobe. Image Credit: DEVELOP JPL Team.

Authors: Michael Fong, Ryan Boarman

Mentors/Advisors (affiliation): Benjamin Holt, (NASA Jet Propulsion Laboratory/JPL)

Past or Other Contributors: Austin Madson, University of California, Los Angeles

Daniel Cusworth, University of California, Los Angeles

Edgar Vargas, University of California, Los Angeles

Katrina Laygo, University of California, Los Angeles

Team Location: Jet Propulsion Laboratory, Pasadena, California

Abstract: The water quality of the coastal ocean and the safety of beaches for public use is potentially threatened by pollution from urban runoff and wastewater effluent. Urban stormwater runoff is currently the most significant pollution hazard for coastal waters in the Southern California Bight (SCB) coastal region, and has become an increasingly pressing public policy issue, with the city of Los Angeles spending more than $100 million in Proposition O funds for safe, clean beaches. Our study is composed of two parts: an examination of stormwater plumes from historical synthetic aperture radar (SAR) imagery from 2006-2011, and monitoring of the wastewater plume from the Orange County Sanitation District outfall diversion event in fall 2012 with Advanced Spaceborned Thermal Emission and Reflectance (ASTER) thermal imagery and Earth Observing-1 Mission (EO-1) Hyperion hyperspectral imagery. The stormwater study examined correlations between plume area, precipitation and river discharge. Mean plume backscatter intensity was matched with in-situ beach contamination data (fecal and bacterial concentrations) in order to validate synthetic aperture radar (SAR) imagery as a proxy for hazardous beach conditions and to assess whether the products could have impacted local decision-making. The wastewater study provided satellite observations to inform in-situ monitoring efforts. Using the ASTER thermal imagery, a clear plume signature associated with the diversion event was observed.

Transcript available here.