Does Bacteria Grow in Stagnant Water?

stagnant water bacteria vs benefits
Stagnant Water Supports Life

What do handsome toads and beautiful lotus flowers have in common? Well, aside from having intricate patterns that only nature could produce, their lives depend upon the existence of stagnant water.

In fact if all the stagnant water on earth were to shrivel and dry up, it might just be the beginning of the end.

That’s because beyond the usual disgusting appearance of stagnant water lies a world unseen by the ordinary human eyes. This world is responsible not only for the atrocious and unpleasant characteristics of stagnant water but also to sustaining the established ecosystem. It is the world of microbes.

But no matter how precious and nourishing stagnant water might be for toads and lotus flowers (and millions of necessary microbes) it can just as easily be the source of dangerous, even deadly water-borne diseases.

Do bacteria grow in stagnant water? Yes, they do. Different classes of microbes live and reproduce in stagnant water. But bacteria is chief of them all. In fact, anaerobic bacteria (those that don’t require oxygen) are commonly found in stagnant water and some are downright deadly.

These non-breathing bacteria actually thrive in stagnant water, which is why they are right at home in several fermentative processes that require such bacteria .

Coming up, were going to look at how bad it can be when bacteria take up residence in stagnant water. First, let’s briefly touch upon the definition and the classifications of stagnant water. This will just take a moment…

What Does Stagnant Water Mean

Stagnant water, also known as standing water, refers to water that is not flowing or moving in any direction and remains in place, usually undisturbed for hours, days, weeks, or more extended periods.

Clogged bathroom drain, poorly maintained fish pond, overgrown ditch drains, water puddles from rainfall in the yard or even “swimming holes” all are forms of stagnant water.

Classification of Stagnant Water 

Stagnant water may be categorized as follows. 

  • Trapped water stagnation: It is water that trapped in materials that have been disposed-off—for example, disposed can, bottles, tires, bowls, plant drip trays, etc. 
  • Surface and groundwater stagnation: refers to water bodies like wells, water holes, sewer, ponds, streams, seas, aquifer, etc
  • Waterbody stagnation: refers to water that stagnates in water bodies like rivers and lakes.
Drill Holes in the these types of swings to avoid Trapped Water Stagnation

What Bacterial Diseases are Caused By Stagnant Water

Microbes that cause waterborne diseases are predominantly Bacteria and Protozoa. Most of which are parasites of the human intestinal tract and may also infect the circulatory system through the digestive system. 

Waterborne bacterial disease are not just happening in undeveloped countries. . For example, in the United States, it has been calculated that 560,000 people suffer from waterborne diseases, and 7.1 million suffer from a mild to moderate infection.

Bacterial diseases and infections known for developing in Stagnant water include

  • Botulism
  • Campylobacteriosis
  • Cholera
  • Dysentery
  • E. coli  infection
  • M. marinum
  • Aquarium Granuloma
  • Legionnaires

Infections Caused by Bacterial Pathogens 

Cholera – Rare in USA but

Cholera is a small intestine infection caused by the bacterium Vibrio cholerae, and the usual symptom is watery diarrhea that persists for a few days. There are dehydration and electrolyte imbalance, which may lead to death if not resolved.

The source of cholera is usually other cholera sufferers whose untreated diarrheal excrement is allowed to come in contact with groundwater, public bath, drinking water source, etc. 


Botulism caused by Clostridium botulinum. Though rare in occurrence, it is a fatal disease. Typically symptoms include weakness, blurred vision, trouble speaking.

The bacteria can enter the gastrointestinal tract through drinking contaminated water and also by exposing a wound to contaminated water.


Dysentery caused by Shigellia dysenteriae. Typical symptoms include the passing of excrement with blood and sometimes vomiting of blood. 

It spread by drinking water contaminated with the pathogen. 


Legionellosis is a form of pneumonia caused by Legionella pneumonia. Typical symptoms may include cough, fever, headaches, shortness of breath, muscle pain.

It is spread mostly by aerosolized contaminated water. 

Typhoid Fever 

Typhoid fever is a bacterial infection caused by Salmonella typhi. Symptoms include sustained fever, sweating, diarrhea 

It spreads by drinking water contaminated with the pathogen. 


Salmonellosis is an infection caused by Salmonella spp. Typical symptoms include abdominal pain, headache, fever, diarrhea. It may progress to enlargement of the liver and may extend to five weeks and can cause death. 

It spread by drinking water contaminated with the pathogen.


Leptospirosis is mainly a blood infection caused by the bacterium Leptospira spp. Typical symptoms include fever, muscle pain, headache.

Mode of transmission is through the ingestion of water contaminated by animal urine carrying the pathogen. Highly common in dogs but certainly capable of infecting humans as well.

Otitis Externa 

Otitis Externa is caused by several bacterial and fungal infections. Also called swimmers ear, it characterized by swelling of the ear canal; this could impair hearing.

It transmits by swimming in water contaminated by the causative pathogen. 

Dangers of Stagnant Water caused by Faulty Sewer Ditches and Septic Tanks

Bacterial Contamination of Water by Sewage and Water Treatment Sludge

Sewage contains quite a load of bacterial contaminants. Drinking-Water Sources can be contaminated by a sewage overflow, septic tank, broken sewer lines, and wastewater through a process called cross-contamination. 

Bacterial contamination poses a considerable threat to our water resources and can cause serious diseases when they gain entry into the body system. Most bacterial infections transmitted via the oral-fecal, which means that they come about by ingesting food or water containing fecal matter polluted with the pathogenic bacteria. 

Contamination of water by septic tank can happen in the following ways:

  • Poorly designed percolation system: may allow untreated water to escape. 
  • Wrong Arrangement of septic leach field: can release partly treated wastewater into a drinking water source. 
  • System Failure: This can result in blocking and overflow to surface water. 
  • Dense Arrangement of tanks: leading to areas with an elevated amount of wastewater that can leach to the land surface or end up in the water table.  

In any of the above scenarios, waterborne diseases can spread through groundwater, which is polluted by fecal pathogens from septic tank sewage.

How To Get Rid of Stagnant Water Sources

Remove Trapped Water Sources. 

  • Remove Discarded Artifacts and old debris such as discarded tires, pot, plastic bottles, and other materials that may serve as reservoirs to hold small amounts of water.
  • Dispose of piles of raked leaves, grass, or other brush can collect small pool stagnant water. They also serve as an abode for mosquitoes.
  • Put away kids’ toys. Preferably in watertight boxes or at least under covered area, especially if they are capable of holding small residues of water. 
  • Clean culverts and drains because they can fill up and clog easily. 
  • Drain off water spots such as puddles in your yard. Add sand to aid the water drain off.
  • Regrade lawn if pool forms in some spots. 

 Keep Water Features Clean 

  • Facilitate Movement in Stagnant Water Bodies such as a pond.
  • Consider a fountain feature in a birdbath or at least clean it regularly
  • Clean and sanitize swimming pools as soon as they are open

Remove Standing Water Indoors 

  • Change indoor water containers frequently, for example, the water trough for pet animals. 
  • Repair or replace damaged home gadgets, which may serve as a water reservoir for microbes.


Bacteria can definitely grow in stagnant water, and they cause several diseases to public health, such as cholera, dysentery, and typhoid fever. In fact some bacteria wouldn’t even exist if NOT for stagnant water.

The way to get rid of them is by protecting our water sources from cross-contamination by sewers and by getting rid of standing bodies of water in our immediate environment.


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