Coastal Residents Perception of Seawater Desalination and Its Impacts on Coastal Ecosystems

Sufficient freshwater supply is an increasing challenge for coastal communities in California due reduced reliability of water from inland water sources (e.g. Colorado River, Sierra Nevada) and groundwater sources resulting from changes in weather patterns, recurring droughts, and saltwater intrusion. One option to increase resilience of freshwater availability in coastal areas and to mitigate associated water shortage impacts on coastal ecosystems and communities is an investment in new infrastructure like desalination plants. Such an investment, however, is a difficult decision due to uncertainty about drought duration and intensity, and insufficient knowledge about potential negative impacts of desalination facilities on coastal ecosystems and communities. A number of studies have examined biological impacts associated with seawater desalination and brine discharge in coastal areas. What has been lacking, however, is a systematic and scientifically grounded assessment of coastal resident perceptions regarding seawater desalination plants and their potential impacts on the local coastal ecosystems. Such information would be useful for education, information and planning purposes. Our research addresses this knowledge gap. We randomly surveyed a sample of residents in Carlsbad, California, where the first large coastal seawater desalination plant in California has been built, to understand their knowledge and attitudes towards seawater desalination plants. We assessed residents (1) awareness of the plant and the discharge of brine and the information sources for their knowledge, (2) knowledge about the characteristics of brine discharge and its potential impacts on the coastal ecosystem and coastal activities, (3) attitudes towards seawater desalination plants (support or oppose), (4) perception of negative and positive outcomes from the new desalination plant, (5) the influence of socio-demographic characteristics, place attachment, frequency of ocean use, and membership in an NGO on attitudes and knowledge.