How does untreated wastewater affect public health?

Untreated wastewater poses a significant threat to public health primarily because it serves as a major source of pathogenic microorganisms, including bacteria and other disease-causing agents excreted in feces. When this sewage is discharged into surface water or groundwater without adequate treatment, these pathogens can contaminate water supplies, leading to the spread of disease.1234

Beyond biological pathogens, untreated wastewater often contains industrial wastes, toxic chemicals, and active pharmaceutical ingredients. These substances can cause direct poisoning or long-term health issues in humans, particularly if they enter the food chain through contaminated seafood or water sources. Furthermore, the decomposition of organic matter in untreated sewage depletes dissolved oxygen in aquatic environments, which degrades water quality and disrupts the ecosystems that humans rely on for vital resources.123

Ethically, the management of wastewater is a fundamental responsibility of environmental engineering, as it is essential to protect human life and preserve the integrity of our natural water systems.56