The Impact of Storms on in Cooling Tower Water, Implications for Human Health.

At the U.S. Department of Energy's Savannah River Site (SRS) in Aiken, SC, cooling tower water is routinely monitored for concentrations using a direct fluorescent antibody (DFA) technique. Historically, 25-30 operating SRS cooling towers have varying concentrations of in all seasons of the year, with patterns that are unpredictable. Legionellosis, or Legionnaires' disease (LD), is a pneumonia caused by bacteria that thrive both in man-made water distribution systems and natural surface waters including lakes, streams, and wet soil. Legionnaires' disease is typically contracted by inhaling , most often in aerosolized mists that contain the bacteria. At the SRS, is typically found in cooling towers ranging from non-detectable up to 10 cells/L in cooling tower water systems. Extreme weather conditions contributed to elevations in to 10-10 cells/L in SRS cooling tower water systems in July-August 2017. concentrations in Cooling Tower 785-A/2A located in SRS A-Area, stayed in the 10 cells/L range despite biocide addition. During this time, other SRS cooling towers did not demonstrate this increase. No significant difference was observed in the mean mean concentrations for the towers ( < 0.05). There was a significant variance observed in the 285-2A/A Tower results ( < 0.05). Looking to see if we could find "effects" led to model development by analyzing 13 months of water chemistry and microbial data for the main factors influencing the concentrations in five cooling towers for this year. It indicated chlorine and dissolved oxygen had a significant impact ( < 0.0002) on cooling tower 785A/2A. Thus, while the variation in the log count data for the A-area tower is statistically greater than that of the other four towers, the average of the log count data for the A-Area tower was in line with that of the other towers. It was also observed that the location of 785A/2A and basin resulted in more debris entering the system during storm events. Our results suggest that future analyses should evaluate the impact of environmental conditions and cooling tower design on water concentrations and human health.