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How to Determine the Source of a Flooded Basement in Chicago

Apr 29, 2013 • By Matthew Stock.

How to Determine the Source of a Flooded Basement in Chicago


“There’s water in the basement!”

That’s something no homeowner wants to hear, ever.  The early spring of 2013 has that cry echoing across Chicago as extremely heavy rains have caused flooding and have homeowners all over the city and suburbs bailing out their basements.  As the piles of ruined rugs and soggy cardboard boxes grow at curbs, homeowners are trying to figure out how the flooding happened and how they can prevent it from happening again.

There are many ways in which water gets into a basement; some can be prevented by homeowners, others require action by a municipality.  Those sources fall mostly into one of two categories – seepage or sewage – and each has its own identifying characteristics and methods of repair.

What Caused your Flooded Basement in Chicago – Seepage or Sewage?

Seepage is the name given to water that infiltrates a basement through cracks and openings created by foundation movement and construction techniques.  The water that ends up as basement seepage is in the soil surrounding the foundation and is known as ground water; it is forced through openings by pressure created by expansive soil that swells due to saturation.

Sewage generally refers to the contents of municipal sanitary sewers that carry the waste from household plumbing fixtures.  It can also refer to storm water that is carried by storm sewers.  Chicago has a combined sewer system in which both sanitary and storm sewage are carried in the same pipes.

So, how do you know which one flooded your basement in Chicago?

Quantity – Seepage, although it can amount to a large amount of water over time, enters the basement slowly as the openings are usually no larger than cracks.  One exception is when a sump pump fails and the water that would normally exit through that system overflows the sump basin and spreads across the floor.  Sewage backups, on the other hand, can produce a large amount of water in a very short time, particularly when storm sewer systems are overwhelmed by a heavy rain.

Source – Seepage can generally be traced to wall or floor cracks, porous masonry walls, the cove joint or leakage around basement windows and places where pipe, electrical service or HVAC penetrate the basement walls.  Storm sewage alone will usually enter the basement through floor drains; sanitary sewage (or a mixture in Chicago) will come in through plumbing drains such as utility sinks, toilets or other basement fixtures as well as floor drains.  Sump pumps and sewage ejector pumps should have check valves to prevent backflow.

Cleanliness – Seepage is ground water that may have come from rain, underground aquifers or other natural sources.  The water produced by seepage is generally clear, free of sediments and solids.  Storm sewage by itself should be similar but sanitary sewage, or the combination of the two if you’re on the Chicago combined sewer system, is, well, not so clean and will be discolored, may contains solids and will probably have an odor.

Every situation will be different and bears investigation but a good rule of thumb is that if there’s a relatively small amount of clear water in the basement, it’s probably seepage.  If there’s a lot of water and it’s dirty, it’s likely sewage.  Seepage problems can be permanently repaired by a basement waterproofing contractor.  Sewage backups can be alleviated by a sewer contractor but the ultimate solution lies in the sewer system itself.  The Chicago “Deep Tunnel” project, only partially complete, has begun to ease the pressure on Chicago’s sewers and should be a big help upon completion, although that is projected to be far off.

When seepage is the cause of a flooded basement in Chicago, the homeowner needs a basement waterproofing contractor that knows Chicago homes and their idiosyncrasies.  At U.S. Waterproofing, we have been repairing seepage problems in Chicago basements since our founding in the city in 1957 and we count thousands of Chicago homeowners among our more than 300,000 satisfied customers.  Why not ask for a free consultation?

Tags: chicago basement waterproofing, flooded basement chicago, chicago flooded basement

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