I’m going to solve a mystery for you.
Many homeowners in the Chicagoland area have found orange stains on their basement floor or found a slimy orange/brown sludge in the bottom of their sump basin. Most have no idea what causes it. Some have chalked it up to rust in old plumbing or the chemically impossible “rusty water.” It’s neither.
Let me introduce you to Leptothrix, Clonothrix and Gallionella. Nope, not the Three Musketeers. These hard-to-pronounce names represent three common strands of iron bacteria – the real culprit in the situations above.
Iron bacteria, and there are many, many varieties, are bacteria that live all around us and, when present in water, oxidize iron in order to survive and grow. When the iron, present in a dissolved state, is oxidized the resulting by-product is ferrous oxide, which won’t dissolve in water and creates the slime and discoloration.
The good news is that iron bacteria aren’t harmful. At worst, they can create a musty smell and a metallic taste in water. They are, however, a real danger to basement waterproofing systems.
How Did I get Iron Bacteria in my Home?
Well, don’t worry; you didn’t track it in on your shoes. Iron bacteria are most commonly found in soil and they easily move from soil into ground water. If the bacteria are not native to the soil around your home, there are a number of ways they can get into your water. They may have come from:
Well Water – If your water comes from a private well instead of a municipal supply, look no further. It is extremely common for well water to be contaminated with iron bacteria that leach out of the surrounding soil. Well water is not very common in Chicago and its collar counties.
Contaminated Backfill – If, when your house was built, the soil to backfill against your foundation was trucked in from somewhere else, it may have been contaminated with iron bacteria. When water drains through this soil and finds its way into your basement, iron bacteria come along for the ride.
Contaminated Tools or Equipment – As small as a landscaper’s shovel or as big as a backhoe, anything that digs in dirt elsewhere and then does the same at your house can spread iron bacteria. Even greenery transplanted from somewhere else can bring along unexpected guests.
How Do Iron Bacteria Affect Basement Waterproofing Systems?
The ferrous oxide, also known as iron ochre, that is produced by iron bacteria can become a gelatinous mass that can clog drain tile, both interior and exterior, and gum up sump pumps. While the material is still fluid, a basement waterproofing company can often remove it from the system by a hot-water flush that will kill the bacteria and wash them out into the sump basin.
In dry conditions, such as this summer’s drought, when ground water is scarce, the ferrous oxide can build up in the bed of gravel surrounding drain tile and clog it so that water will no longer drain through it. The slimy, jellied goop can also harden inside the drain tile, becoming an impenetrable clog. In either case, once this stuff hardens, it’s there for good – nothing can make it fluid again and the affected gravel or drain tile must be replaced.
A knowledgeable basement waterproofing professional will know how to design and maintain basement waterproofing systems that will resist clogging from iron bacteria. Materials, such as the piping and surrounding gravel bed, can be modified to reduce the likelihood of clogging with ferrous oxide. Clean-outs can be installed in the system to facilitate flushing.
Chlorine is also an effective treatment for iron bacteria and a basement waterproofing company can not only incorporate it into a drain tile system but can create an easy and effective way for the homeowner to continue its application.
We’ve done battle with iron bacteria many times at U.S. Waterproofing, and we’ve always won out on behalf of our customers. If you’re noticing that things are starting to look a little rusty in your basement, why not have one of our basement advisors assess the problem? Our advice is always free.