After a flood or hurricane, it is important to be aware of the hazards present in the floodwaters. These hazards include biological and chemical contaminants that can be harmful to humans. Microorganisms such as viruses, bacteria, and mold can thrive in standing water and wet materials, and exposure to these contaminants can cause diseases and trigger allergic reactions. Furthermore, the damage caused by these contaminants can persist long after the flood. It is difficult to determine what exactly is present in the floodwater at any given time, so it is best to exercise caution and avoid contact with the water if possible.

Floodwater can contain:

Downed power lines

Human and livestock waste

Household, medical, and industrial hazardous waste (chemical, biological, and radiological)

Coal ash waste that can contain carcinogenic compounds such as arsenic, chromium, and mercury

Other germs and contaminants that can lead to illness

Physical objects such as lumber, vehicles, and debris

Wild or stray animals, such as rodents and snakes