Floodwater Contamination: What Is in Floodwater?

Floodwaters have some of the worst water quality ratings, carrying a toxic soup of contaminants. Across Mississippi, Alabama, Tennessee, and Georgia, the threat of flooding makes it essential for your safety to understand what could be in your floodwaters. 

Below, we’ll break down the most common floodwater contaminants, their health consequences, and what you can do to stay safe during a flood. 

Why Are Floodwaters a Health Risk?

These contaminants can spread widely through a flooded region. The radius of impact will vary based on how the water flows and mixes, but an entire watershed could be impacted.

One major example of how these contaminants can spread is the Gulf of Mexico dead zone, which is caused by agriculture and industrial pollutants being carried through the Mississippi River watershed and into the Gulf, creating areas of water where nothing can survive. 

By looking at the potential pollution sources near your home, you can identify what potential contaminants could be in your floodwater. One of the most common flood contaminants is sewage because during a flood, sewage treatment plants will overflow and underground septic systems can leak.

Most Common Floodwater Contaminants and Threats

• Sewage
• Livestock waste
• Bacteria and infectious organisms
• Bleach and cleaning products
• Superfund contaminants
• Live power lines
• Chemicals and pesticides
• Medical and industrial waste 
• Coal ash
• Gasoline, battery acid, and hazardous fluids
• Rodents and snakes

How Can Floodwater Exposure Affect Your Health?

Contact with floodwaters can be dangerous for your health. The specific contaminants will determine your reaction. However, vomiting, rashes, and infection are common. The high sewage content also brings bacterial risks for E.coli, salmonella, and other pathogens that can cause vomiting, fever, diarrhea, or stomach cramps. 

Common Floodwater Exposure Risks

• Wound infections
• Hepatitis A virus
• Typhoid, paratyphoid, and tetanus
• Skin rashes
• Gastrointestinal illness
• Trench foot 
• Electrocution 

The CDC recommends that contact with floodwater be avoided, and if you do come in contact, wash the area with soap and clean water as soon as possible. 

How Has Alabama Been Impacted by Contaminated Floodwater?

It doesn’t take a hurricane or flash flood for major instances of contamination. Tuscaloosa had several sewer overflows in 2020.  In one case, six inches of rain resulted in several sewer spills. In Birmingham and Tuscaloosa, more than 18.5 million gallons of sewer water spilled into floodwaters over a 10-day period. Millions of gallons also overflowed in Decatur. 

Alabama also has an increasingly common problem with vibriosis, sometimes called flesh-eating bacteria. The water-borne disease can enter your bloodstream through a cut, insect bite, recent tattoo, or skin abrasion, causing a severe infection. Up to one in three people who develop this necrotizing fasciitis die from the infection. 

Vibriosis Cases in Alabama 

• 2017: 26 cases
• 2018: 38 cases
• 2019: 47 cases

How High is Your Flood Risk?

Flood damage can be expensive, and In the U.S., flooding causes about $4 billion in damages annually. Properties throughout the southern states are at risk. In addition to the storms coming up from the Gulf Coast, the region also faces runoff and drainage flowing down from states along the Mississippi River. 

To determine your flood risk, you can enter your address into Flood Factor, which offers one of the most comprehensive flood modeling tools. Across the AFS service area, flooding is highest in Mississippi, followed by Alabama, Tennessee, and Georgia.

Flood Risk

• Mississippi: 22% of properties at risk
• Alabama: 17% of properties at risk
• Tennessee: 15% of properties at risk
• Georgia: 12% of properties at risk

How Can You Improve Flood Safety and Reduce Property Damage?

During a flood, follow all safety recommendations including staying out of floodwaters to avoid exposure. Don’t drive through floodwaters, and call a pro about septic system failure, floating propane tanks, electrical issues, and flooded crawl spaces.

Flood mitigation can have a significant impact on how your home survives a flood and how much damage it sustains. For example, yard drainage and grading can help keep floodwaters flowing away from your home. An analysis about flood mitigation in Florida found that $19 million was invested in flood mitigation projects before Hurricane Matthew, and these improvements helped the state avoid $81 million in damages. That’s a 422 percent return on investment (ROI).

Some flood mitigation systems such as sump pumps are so effective that they can help homeowners qualify for monthly insurance discounts or policy credits up to $1,000 toward installation. Plus, comprehensive systems for basement waterproofing and crawl space repair can help protect your home from flooding and keep your household safe. 

Sign up for a free consultation from the foundation repair and waterproofing experts at AFS to learn how you can protect your home from damaging floodwaters.