Stormwater runoff in coastal Southern California – Comparing satellite plumes with in situ bacteria measurements

Coastal regions around the world have historically attracted large human populations. Coastal zones offer accessibility to trade, transport, nutrition, and recreation for developing countries. The urbanization of coastal regions has directly influenced environmental decline and ocean pollution from stormwater runoff. The Southern California Bight (SCB) is home to nearly 25% of the coastal population of the United States, a growing concern for the volume of pollution discharge that flows from these coastal areas. As the population grows in the SCB, the extent of impervious surfaces also grows, reducing the amount of rainwater that percolates back into the soil and increasing the rates of stormwater runoff. Stormwater runoff leads to bacterial overgrowth harming beach water quality along highly populated coastal cities. Besides the growing bacterial contamination, runoff adds health hazards to the greater portion of the coast. Previous studies using satellite SAR sensors and other remote imaging techniques enables spatial and temporal evaluation of surface material and sediment discharge in the upper ocean discharge that potentially pollute ocean ecosystems. The anthropogenic debris that flows into the oceans can be analyzed as surface particulate matter which includes heavy metals, emission pollutants and suspended solids. Stormwater runoff debris can change the geochemistry of the ocean creating hazardous environments for local communities who depend on beaches for recreation and for marine life. Heal the Bay (HTB) is a non-profit organization committed to making ocean conditions optimal along California, that includes obtaining beach collections of water quality obtained during and after storms. This study will evaluate both recent and past satellite SAR and high resolution optical imagery with in situ measurements provided by Heal the Bay to examine the properties of detectable runoff plumes in relation to bacterial contamination affecting the SCB and evaluate the effectiveness of using satellite-detected stormwater plumes as a useful method to determine contaminated coastlines.