Surveillance Webinar: Public Health and Waterborne Illness-Surveillance Webinar: Public Health and Waterborne Illness PPT Slides

Surveillance Webinar: Public Health and Waterborne Illness PPT Slides

Pdf Summary

This webinar, presented by Dr. Sharon Balter of the Los Angeles County Department of Public Health on January 29, 2026, focused on public health concerns related to waterborne illness and drinking water safety in the U.S. The session reviewed the evolution of drinking water systems and regulation, common waterborne pathogens, and challenges in water treatment and surveillance.<br /><br />Early U.S. water systems were primarily built for fire suppression, with drinking water as a secondary benefit. Rapid urbanization historically led to outbreaks of diseases like cholera and typhoid. Modern water standards developed with chlorination beginning in 1909, federal bacteriological standards by 1914, and the Safe Drinking Water Act in 1974, which established enforceable Maximum Contaminant Levels (MCLs) and treatment requirements.<br /><br />Waterborne pathogens include bacteria (E. coli, Salmonella, Shigella), viruses (Hepatitis A, Norwalk), and parasites (Cryptosporidium, Giardia), some resistant to chlorine disinfection. Conventional water treatment involves coagulation, sedimentation, filtration, and disinfection; additional processes target hardness, corrosion, and specific contaminants like arsenic. Monitoring includes turbidity and disinfectant residuals to detect risks.<br /><br />Two major case studies illustrated risks from water contamination: the 1993 Milwaukee Cryptosporidium outbreak traced to surface water treatment failures, and the 2014 Flint, Michigan crisis where a switch to corrosive Flint River water without corrosion control resulted in lead leaching and a Legionella outbreak causing deaths. The Flint incident underscored the consequences of governance failures and regulatory lapses.<br /><br />Legionella pneumophila, found in warm water and biofilms within building water systems and cooling towers, causes Legionnaires’ disease. The 2015 Bronx outbreak linked to contaminated cooling towers emphasized the importance of rapid investigation, environmental testing, and policy enforcement.<br /><br />Key takeaways highlighted the complexity of water systems, the critical role of collaboration between public health and water engineers, the need for vigilant surveillance, and the importance of community engagement to detect and respond to waterborne threats. Future webinars will cover food surveillance topics.

Keywords

waterborne illness

drinking water safety

public health

water treatment

waterborne pathogens

Safe Drinking Water Act

chlorination

water contamination outbreaks

Legionella

water system surveillance