How to Remove Iron Bacteria from Well Water

Updated February 8th, 2023

If your drinking water comes from a private well, you will likely experience issues with iron in your water. These issues can range from poor-tasting coffee to bright orange streaks in toilets and bathtubs. However, there’s an equally familiar but less understood problem linked to iron contamination: iron bacteria, also known as “iron-eating” or “iron-oxidizing” bacteria.

Iron is one of the most abundant minerals in the earth’s crust. As a result, elevated levels of iron are usually widespread in the groundwater that serves wells, often fostering the growth of iron bacteria in well water. These organisms can combine oxygen with iron, manganese, or other nutrients in the water to form a swampy sludge containing rust deposits, bacterial cells, and other organic and inorganic matter. This slimy residue then sticks the bacteria to pipes, pumps, plumbing fixtures, and appliances, causing clogging, foul tastes and odors, corroded pipes and plumbing fixtures, etc.

Well-water systems used infrequently or intermittently are typically more prone to iron bacteria problems. To make matters worse, removing these organisms from your water can be complicated, which is why we recommend taking steps to prevent them from forming in your well in the first place. Luckily, this article explains a highly effective way to remove iron bacteria from well water. Let’s start by discussing what iron bacteria are and how they get into well water.

What are Iron Bacteria, and How Do They Enter a Well System?

Iron bacteria are microorganisms that occur naturally in soil, surface water, and shallow groundwater. While most bacteria get their energy from decomposing organic matter, iron bacteria derive theirs from oxidizing dissolved ferrous iron or manganese in groundwater. Gallionella spp. and Lepothrix spp. are the two common bacterial species involved in iron and manganese oxidation.

Although a small population of iron bacteria can naturally occur in groundwater, they typically exist in abundance above ground. The most common way for these organisms to enter wells is when the bacteria enter from the ground surface during well drilling, submersible pump installation, or any other construction, maintenance, or well servicing. For instance;

  • If un-chlorinated surface water is used as drilling water, it may contain iron bacteria and introduce the bacteria into the groundwater.
  • During installation or repairs of a well, if the pipes and pumps are laid on the ground, soil containing iron bacteria can enter the groundwater.
  • If the Driller’s equipment is contaminated with iron bacteria, it can spread the bacteria from well to well.
  • If you had your well serviced and the pump was not properly sanitized before returning to the well, bacteria can be introduced that will then bond with the iron.
  • After construction, iron bacteria can enter a poorly constructed or maintained well through flooding surface water, septic systems, or other sources.

Iron has two forms in the environment, ferrous iron (soluble in anaerobic or oxygen-free environments) and ferric iron (insoluble in aerobic or oxygen-rich environments, forming solid, rust-colored particles). When de-oxygenated groundwater reaches an oxygen source, iron bacteria use the oxygen to convert the ferrous iron into ferric iron, changing the iron into a slimy rust-colored residue made up of living and dead bacteria, secretions, sheathes, stalks, and other materials the bacteria left behind. This sludge or biofilm can also appear as a soft or filamentous organic material due to the bacteria’s growth.

Once the iron bacteria enter the well system, their next destination is in your drinking glass. The iron-bacteria-contaminated water is pumped to your home’s plumbing system through pipes to your faucets. Unless your home is fitted with a filter or some other line of defense to block the bacteria from entering, you’ll likely ingest them through your drinking water.

Signs of Iron Bacteria in Water

If your household water supply is contaminated with iron bacteria, you might notice several unappealing signs that may indicate iron bacteria presence. These signs may include:

Iron bacteria sludge in back of toilet

· Stains and deposits on plumbing fixtures, pipes, and appliances

One of the most common indicators of iron bacteria in well water is stains and deposits on plumbing fixtures, pipes, and appliances. Water containing these organisms will leave rust-colored slime stains and deposits in sinks and toilets and inside well casings. You’ll also notice stains on fixtures, tableware, laundry, and various surfaces, that keep coming back no matter your cleaning method or efforts. These stains can be grey, yellow, or brown but are often a reddish-orange rust-like color.

· Discoloration

Water containing iron bacteria can have a yellow, red, or orange hue. Further, visible deposits that have a clumpy or slimy consistency are very likely to have been caused by the presence of iron bacteria. Iron bacteria deposits are widespread in toilet tanks. In many cases, the deposits will take the form of a slimy coating along the walls of the tank. If the bacteria have been in the water for a lengthy period, the deposits could float in the water.

· Oily sheen on the water surface

A quick and easy way to check for the presence of iron and other slimy-producing bacteria is to look in the water closet tank of your toilet. If you see an oily sheen on the surface of the water and can feel a slimy residue on the inside of the tank, slime-producing bacteria are likely present in your water system. If you use disinfectant in your tank, evidence of these conditions might not be so apparent.

· Unpleasant tastes and/or odors

Typically, iron bacteria cause water to have an odor that resembles rotten eggs, fuel oil, cucumber, or even sewage or swamp. The smell may be noticeable only in the morning or after extended periods of non-use. The water may also taste like rotten vegetables. If you or your guests ever comment on any of these signs, you likely have an iron bacteria problem. We should note that iron bacteria do not produce a rotten egg smell in the house but rather sulfur bacteria.

· Corrosion of plumbing equipment

Iron bacteria can form micro-zones of high acidity and elevated concentrations of corrosive ions inside your plumbing, causing the plumbing equipment to corrode. The corrosion is usually worst in areas that hold stagnant water. So, if you notice your pipes and plumbing fixtures have started to rust excessively, this corrosion could be caused by the presence of iron bacteria in your water.

·  Clogging of wells screens and pipes

If the water yield of your well decreases unexplainably, it may be the result of a significant growth of iron bacteria and the slime they produce. The slimy residue produced by iron bacteria can build up in pipes and cause clogging, therefore reducing water yield inside your home and restricting water flow to your washing machine, water heater, dishwasher, or other water-using appliance. This restricted flow can also affect water softeners and water filter systems. For instance, a restricted water softener drain link can prevent the system from flushing properly, potentially damaging the water softener resin. Over time, the softener will likely “plug up” with slime, causing little to no water flow. Reverse osmosis systems and carbon filters are even more sensitive, as bacterial slime can foul these products more quickly.

· Increased infestations of other types of bacteria

Iron bacteria can foster conditions where other types of bacteria, including coliform and sulfur bacteria, can thrive. The rotten egg smell we mentioned above isn’t produced by the iron bacteria themselves, but the sulfur bacteria are sometimes produced due to iron bacteria. That means, if your water contains iron bacteria, it may also have other bacteria types that you also don’t want in your drinking glass.

Is Iron Bacteria in Water a Health Risk?

The presence of bacteria in your drinking water isn’t necessarily a health hazard. Certain types of bacteria in household water are more of a nuisance issue.

Testing for Iron Bacteria

Well water test kit by ETR Laboratories

There are very few water laboratories that test for iron bacteria, you can get a water test here. Perhaps that’s because there are no drinking water standards for iron bacteria since there are no health implications. Thus, water tests looking for iron bacteria are seldomly recommended and are generally not required. Here’s a brief description of a simple visual test:

  • Remove the screen or faucet-mounted filter from the faucet if there’s one present.
  • Fill a clean, sealable, clear glass container with water from the faucet, preferably one that’s been unused for several hours, for example, early in the morning before any other household water use.
  • Leave the sample intact in the container and let it sit undisturbed for about 24 hours.
  • If the water remains clear after 24 hours, there are neither precipitates of oxidized iron and manganese nor iron bacteria in the water.
  • If the sediment at the bottom appears as a thin layer of rusty, flour-like substance, it is likely just precipitates of oxidized iron or very few iron bacteria (if any) in the water.
  • If the sediment settled at the bottom consists of rust-colored fluffy strands or clumps, there is likely a substantial amount of iron bacteria present.

Although a simple visual inspection is usually sufficient at indicating whether your water supply contains iron bacteria, you can still go ahead and test your water for iron bacteria at a certified laboratory in your area.

Some laboratories provide containers and instructions to allow you to sample the water for iron bacteria. Laboratory analysis of your water can reveal the extent of the iron bacteria problem and provide other vital information like hardness levels, alkalinity, pH, etc.

The National Testing Laboratories, Limited provides a quality and reliable iron-bacteria water testing kit that includes specific instructions for water collection and delivery. The laboratory test results are usually reported out in a couple of days to a few weeks, depending on the laboratory facility.

How to Prevent Iron Bacteria from Entering Your Well System

Once iron bacteria are introduced into a household water supply, they can be tough to remove altogether. Therefore, it’s always better to prevent them than try to remove them. To significantly reduce the chance of any iron bacteria entering your well system, the drilling process, the submersible pump installation, assembly, and any repair and maintenance activities must be performed with strict preventative measures in mind.

Here are a few prevention methods:

  • Keep drill bits, pumps, and lengths of casing pipe clean and off the ground.
  • Only place disinfected water in a well for drilling, repair, or priming pumps. Never use water taken from surface sources like lakes, rivers, streams, or ponds.
  • Ensure the well casing is capped, watertight, and extends at least one foot above the ground.
  • Disinfect the well, pump, and plumbing after repairs.

Treating Iron Bacteria in Well Water

Once you know for sure that your water contains iron bacteria, you’ll want to start considering ways to get rid of them. Two of the most frequently recommended solutions are “shock chlorination” and chemical injection.

· Shock Chlorination and Flushing

Shock chlorination involves adding an intense chlorine concentration (about 200 ppm) to the water to disinfect it. Chlorine is a common disinfectant used in water systems. It is highly toxic to coliform bacteria and similar bacteria types. It also kills other unwanted microbes like parasites, viruses, fungi, molds, and algae that commonly grow in water supply reservoirs, inside well casings, plumbing lines, and storage tanks. However, iron and sulfur bacteria are more resistant to the killing action of chlorine because they occur in thick layers and are protected by the slime they secrete.

For iron bacteria, the iron dissolved in the water may absorb some of the chlorine before it reaches the bacteria. As such, we recommend a higher chlorine concentration of about 500 ppm to address iron and sulfur bacteria problems. We also suggest that you shock-chlorinate your well about 2-3 times per year if you are experiencing bacteria and not using a continuous chlorinator or chemical injection system. Without a continuous injection of a disinfectant, the iron bacteria will likely resurface and continue to cause problems in your water.

· Chemical Injection

Chlorine Chemical Injection System
SpringWell’s Chemical Injection System

As the name implies, a chemical injection system is a piece of equipment designed to feed chemicals or chemical compounds into a water system to treat microbial contamination problems in water. Chemical injection systems are a step above shock chlorination because they automatically feed chlorine (calcium hypochlorite pellet or liquid sodium hypochlorite) continuously or intermittently into the well water using a chlorinator pump. The chlorine is drawn from a solution tank and pumped into the pipeline under pressure, then mixes with the well water in a contact tank until it’s needed. Temporarily storing the water in a tank allows the water to have enough contact time with the chlorine for complete disinfection and oxidation to occur. Based on how fast the water is flowing, more or less chlorine is pumped into the water to maintain a precise residual.

Now, you probably don’t want the chlorine sticking around in your drinking water after it’s done its job. Not only can chlorine cause an unpleasant taste and smell, but it may bleach out clothing and laundry, burn your eyes and nose, and cause other health risks when consumed long-term. Thankfully, a chlorine injection system often includes a filtration component to dechlorinate the water and eliminate other potentially toxic contaminants. Units like the Springwell CIS Well Water Chemical Injection System don’t come with a built-in carbon filter, but you can add a carbon whole-house filtration system to eliminate chlorine from the water. The goal here is to ensure no chlorine gets into the household water supply, only clean, healthy, great-tasting water.

The CIS Well Water Chemical Injection System is powerful enough to kill iron bacteria, achieving accurate chlorine residuals to give you the best results possible. With one of these systems in place, you’ll be able to enjoy clean and clear water from every faucet in your home – no foul odors, tastes, or stains, and longer-lasting plumbing and appliances.

Unlike many outdated pellet chlorinators that drop pellets into your well and create more extensive issues in your well-water system itself, the CIS mixes chlorine with the water and kills the bacteria on contact. The included instructions guide teaches you how to combine your standard 99% bleach from any store with water. The system is also easy to install, plugs in a standard 110-v wall outlet, and delivers the correct chlorine dosage controlled by a flow sensor for consistent and optimal results. Plus, like all our other Springwell filtering and softening product, it comes with a lifetime warranty on the tank and valves and a six-month money-back satisfaction guarantee. You also get more than 50% in factory-direct savings.

Order the Springwell CIS Well Water Chemical Injection System and a well water filtration system from Springwell today for clean, iron-bacteria-free drinking water. Also, if you have any questions or concerns, you can reach us at 800-589-5592 or send us a message via our contact page.

Final Thoughts

While iron bacteria aren’t necessarily harmful to a person’s health, they foul the water’s taste and create unpleasant odors that can be difficult to handle. Iron bacteria is also highly corrosive and can cause extensive damage to your equipment and plumbing, which is why it’s vital to detect and eradicate iron bacteria as quickly as possible. With the specific guidelines above, you should be able to remove iron bacteria from your water effectively.