CHEE Seminar: Natalie Mladenov
Monday, November 13, 2023 – 3:00 p.m.
Natalie Mladenov
Professor, William E. Leonhard, Jr. Chair
Director of the Water Innovation and Reuse Lab
Civil, Construction and Environmental Engineering
San Diego State University
“Leaky Sewers or Homeless Encampments? Discriminating Urban River Pollution Sources During Storm Events”
Speech & Hearing Building, Room 205
Social Hour will immediately follow the seminar in Old Engineering 157 (Graduate Student Lounge).
ABSTRACT
Water quality benchmarks for fecal indicator bacteria (FIB) are often exceeded in many urban streams in southern California. The different FIB pollution sources, including leaky sanitary sewers, illegal discharges, and open defecation, have been a matter of debate. Teasing apart the different sources remains a challenge, especially when untreated wastewater and runoff from open defecation sites both contain human fecal material. To distinguish the various sources of microbial contamination in an urban stream, temporal trends in biological and chemical markers of anthropogenic contamination were evaluated in the San Diego River and its tributaries during multiple storm events. Results revealed that sewage flushed from the vadose zone was the main source of microbial pollution to the San Diego River, while open defecation near homeless encampments in the river margins was not a major source. The combined use of caffeine/sucralose ratios and HF183 and PMMoV holds promise for identifying sewage inputs to surface waters. These findings highlight the need for maintenance and repair of aging sewer infrastructure.
BIOSKETCH
Dr. Natalie Mladenov is a professor in the Department of Civil, Construction & Environmental Engineering and leads the Water Innovation and Reuse Laboratory (WIRLab) at San Diego State University. Mladenov’s research into fundamental biogeochemical processes that control pollutant mobilization, fate, and transport in natural and engineered system has been applied to diverse problems in environmental engineering. The WIRLab research team has evaluated the drivers of microbial contamination and microplastics generation in surface waters, tested water quality sensors for tracking of sewage contamination and source water control, evaluated the performance of onsite and decentralized wastewater treatment systems, and studied the mobilization of arsenic in groundwater. Mladenov co-leads the SDSU Water Across Borders Big Idea, which unites colleagues from both sides of the US-Mexico border to address needs and questions related to water in the border region.