Have you checked the back of your toilet tank recently?
We know that sounds weird. If you rely on well water, you might discover a surprising sight: a jellyfish-like substance with strands, or other unusual, gelatinous formations. This is likely the result of slime-forming bacteria, often caused by the presence of iron or sulfur bacteria in your water.
Iron bacteria feed on dissolved iron or manganese in groundwater, creating the slimy residue as a byproduct. Although their appearance can be off-putting, these bacteria are typically a nuisance rather than a health hazard, affecting the aesthetic and functional quality of your water rather than its safety.
Causes of slime. Slime-forming bacteria in toilet tanks often develop in environments with low dissolved oxygen, mild temperatures, and dissolved iron or manganese. Remarkably, these bacteria can thrive even when iron levels are minimal.
The taste and odors associated with slime-forming bacteria are commonly described as swampy, musty, or reminiscent of sewage. While these characteristics can be unpleasant, the bacteria are generally considered a nuisance rather than a health hazard, emphasizing the importance of regular maintenance and appropriate water treatment solutions.
Iron bacteria
Iron bacteria, also called iron algae, utilize dissolved iron or manganese in groundwater as an energy source, generating slime as a byproduct. While their presence may be visually unpleasant, they are typically categorized as a nuisance rather than a health hazard.
In addition to the commonly seen orange discoloration, iron bacteria can cause deposits in shades of red, yellow, brown, or even gray. These deposits, along with their slimy texture, can affect the aesthetic quality of water and lead to clogging in plumbing systems, further emphasizing the need for effective management and treatment. Where the water also carries iron above the staining line, the iron itself is a separate problem with its own filter.
Sulfur-forming bacteria
Sulfur-forming bacteria are categorized into two types: those that oxidize sulfide into sulfate and those that reduce sulfate into sulfide, producing hydrogen sulfide gas in the process. These bacteria rely on sulfur as their primary energy source instead of iron or manganese.
Similar to iron bacteria, sulfur-forming bacteria thrive in low-oxygen environments with moderate temperatures and can form slimy deposits. While generally considered an inconvenience rather than a health risk, sulfur-reducing bacteria are often identified by the characteristic “rotten egg” smell caused by hydrogen sulfide gas. They can also produce a darker-colored slime, further impacting the aesthetic and functional quality of water systems. The smell has its own page.
What to know
Regular testing for coliform bacteria is essential to ensure the safety of your water supply. However, testing specifically for slime-forming bacteria is generally unnecessary. These nuisance-class bacteria, while not harmful to health, can lead to issues such as unpleasant taste and odor, staining, and clogged plumbing systems.
Eliminating slime-forming bacteria from a well entirely is nearly impossible. As a result, the best practice is to focus on treating the water as it enters the home. This approach ensures the water remains functional, clean, and aesthetically pleasing while minimizing the impact of these bacteria on your plumbing and appliances.
Treating slime-forming bacteria
Several factors contribute to the presence of slime-forming bacteria in wells. If a well has been inactive for an extended period, it’s generally best practice to chlorinate the well before considering more invasive measures. Well cleaning and shock chlorination is that first step.
If chlorination (commonly referred to as “shocking the well”) does not resolve the issue and the problem persists, continuous chlorination combined with oxidizing filters is often the recommended approach. This method not only addresses the bacteria but also helps prevent recurrence, ensuring a cleaner and more reliable water supply. On the Chatfield line, that is chlorine injection with retention and carbon, sized from a test rather than a guess.
