Yes, you can get sick if someone poops in the pool. The presence of fecal matter in recreational water poses a significant health risk. These illnesses are formally known as Recreational Water Illnesses (RWIs), which are infections spread by swallowing, breathing, or having contact with contaminated water. Because a swimming pool is a shared water environment, it is highly susceptible to contamination from even small amounts of fecal residue. RWIs are a broad category of sicknesses that can affect the gastrointestinal tract, skin, ears, eyes, and respiratory system. The most common illnesses, however, are diarrheal, caused by pathogens that originate in the feces of an infected swimmer.
How Fecal Matter Spreads Illnesses in Water
Even a tiny amount of fecal matter, including residue left on an unwashed body or a “fecal accident,” can contaminate the entire volume of water. The infectious dose for some pathogens is extremely small, meaning a person only needs to swallow a few organisms to become ill. While chlorine is used to disinfect the water, this chemical takes time to work, known as contact time, and is not instantaneously effective against all germs.
The effectiveness of chlorine depends on the type of pathogen present. For many common bacteria, chlorine at standard levels is effective in less than a minute. However, certain parasites are protected by a hard outer shell, making them highly resistant to typical chlorine concentrations. This resistance allows the pathogen to survive in the pool for hours or even days, continuing to pose an infection risk to other swimmers.
Common Germs That Cause Sickness
The most common and concerning pathogen transmitted through fecal contamination in pools is the parasite Cryptosporidium, often referred to as “Crypto.” This germ is the leading cause of swimming pool-related outbreaks because it exhibits extreme resistance to chlorine. A single-celled oocyst of Cryptosporidium can survive in properly chlorinated water for more than 10 days. The resulting illness, Cryptosporidiosis, is a severe diarrheal disease that can last for up to two weeks.
Another parasitic threat is Giardia intestinalis, which causes the diarrheal illness Giardiasis. While Giardia is more susceptible to chlorine than Cryptosporidium, it still requires approximately 45 minutes of contact time with standard chlorine levels to be inactivated. The illness typically involves symptoms like diarrhea, gas, and abdominal cramps.
Other pathogens include bacterial strains like Escherichia coli and viruses such as Norovirus. These germs are also spread through fecal matter, but they are typically killed by chlorine in less than one minute. Norovirus, which causes sudden nausea and vomiting, is also a concern, though it is relatively less resistant to chlorine than the two main parasites.
Preventing Contamination and Emergency Response
The public plays a direct role in preventing the spread of RWIs by following “Healthy Swimming Behaviors.” This includes showering with soap and water before entering the pool to remove any potential fecal matter residue from the body. Swimmers must refrain from entering the water if they are currently experiencing diarrhea or have been sick recently. Infants and young children require frequent bathroom breaks and must wear appropriate swim diapers to contain any potential accidents.
If a fecal incident is observed, the response must be immediate to protect other swimmers. All patrons must be directed to exit the pool, and staff should be notified immediately to close the area. The visible fecal matter must be removed using a net or bucket. The pool should not be reopened until professional disinfection procedures, known as hyperchlorination, have been completed. This process involves significantly raising the chlorine concentration for many hours to ensure the inactivation of chlorine-resistant germs like Cryptosporidium.