Category: Monitoring Environmental Health and Disturbances
Project Team: Los Angeles Oceans II
Team Location: NASA Jet Propulsion Laboratory – Pasadena, California
Benjamin Holt (Oceans-Ice Group, NASA Jet Propulsion Laboratory)
Michelle Gierach (Oceans-Ice Group, NASA Jet Propulsion Laboratory)
Nick Rousseau (Center Lead)
The Hyperion Water Reclamation Plant (HWRP) is one of the largest wastewater treatment plants in the western United States. Treated sewage is generally released at depths of approximately 60 m through 8.05 km outfall pipes into a deep marine canyon in the Santa Monica Bay. In times of repair and maintenance, services on the main outfall pipe are temporarily suspended and require the plant to divert treated sewage to a shorter 1.6 km pipe that extends into shallow coastal zones. These shallow zones make it possible for the buoyant freshwater plumes to reach the surface, potentially contaminating the coastline environment. A six-week diversion event occurred at HWRP from Sept. 21 to Nov. 2, 2015. This project integrated previously obtained NASA satellite images and ancillary data collected by other scientists. By combining remotely-sensed observations with GPS-equipped drogue surface drifters and in situ readings of temperature, salinity, atmospheric aerosols, colored dissolved organic matter (CDOM), and chlorophyll-a florescence, an accurate assessment of the full impact and extent at which these effluent plumes affected the Los Angeles Basin is possible. The outcome of this study can aid in developing proper methods to avoid harmful outcomes during similar diversion events in the future.