Spoiling the Fun: E.coli Bacteria at Iowa Beaches

What are Escherichia coli (E. coli)?

E. coli are bacteria found in the environment, food, and intestines of people and animals. The Iowa Department of Natural Resources monitors state park beaches for E. coli. Some strains of E. coli can cause adverse human health effects, but high levels of the bacteria can indicate the presence of other harmful pathogens or disease-causing microorganisms in the water due to fecal contamination.  

What causes E. coli in water?

According to the Iowa DNR, water can become contaminated by fecal matter from “improperly constructed or operated septic systems and sewage treatment plants, manure spills, storm water runoff from lands with wildlife and pet droppings, or direct contamination from waterfowl, livestock, or small children in the water.” Rain also contributes to temporary spikes in E. coli by bringing fecal matter from the beaches to the water. Swimming in contaminated water usually only results in illness if water is swallowed.

Health Impacts

Children and elderly adults are the most vulnerable to waterborne illnesses, as well as individuals with weakened immune systems. The Iowa Department of Public Health notes that contaminated water can lead to: 

• diarrhea, 
• skin, ear, or respiratory infections, 
• bloody stool, and 
• in rare cases, permanent damage to the kidneys. 

Environmental Impacts

According to Iowa DNR, fish from lakes with high levels of bacteria are safe to eat. E. coli has no effect on the population levels of fish or their health. However, it is important to safely prepare fish by properly washing, cleaning, storing, and cooking them.

Economic Impacts 

E. coli has little impact on the look of the lake. However, various forms of runoff can contribute to the murkiness of the lake.

As the Iowa Lakes Valuation Project shows, Iowans value water clarity and low levels of bacteria. If murkiness or high concentrations of bacteria are noted, individuals may stay away from certain lakes. In turn, there is an economic loss associated with the loss of visitors.

Get more information on the value of Iowa's recreational lakes.

Preventing Exposure 

According to the Iowa DNR, the best ways to prevent exposure are: 

• avoid swimming after heavy rainfall, 
• avoid swallowing water,
• check for leaks in your child’s diaper frequently, and
• avoid swimming if you have or have recently had diarrhea.

Responding to Exposure 

The Iowa Department of Public Health recommends practicing good hygiene before and after going in the water. If you think you have a recreational water illness that needs medical attention, contact your health care provider. Report suspected recreational water illnesses to your local health department. 

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