Assessing Particulate Emissions from Power Plant Cooling Towers

Cooling towers from power plants and other applications use valuable fresh water to dissipate waste heat. Simultaneously, these cooling towers can emit particulates into the atmosphere, potentially worsening ambient air quality. The details of these emissions are poorly known and usually calculated based on estimates published decades ago. This study measured particulate matter emissions from cooling towers at two power plants located in California, one using brackish water and the other using fresh water. The results showed that (1) using brackish or fresh water does not influence particulate matter emissions from cooling towers, (2) cooling towers scrub nearly all the particulate matter between 2.5 and 10 microns from the air that enters the cooling tower, resulting in negative emissions, and (3) in regions of California with elevated particulate matter concentrations, cooling towers may scrub more particulate matter from the air than they emit.