Recently the city of Thunder Bay Ontario experienced devastating flooding. There was enough water to flood out the waste water treatment plant. This effectively shut down the sewage collection and treatment system for the entire city. This turned the entire city to a zone without sanitation. Over 1000 houses needed to be evacuated, and some people needed to evacuate immediately.
The flood hit the city at night, and people living in basement apartments woke up to furniture floating in sewage. One lucky family woke up to their baby’s crib (and baby) floating in sewage. The rest discovered that their house smelled horrible when they woke up.
What overloaded the system was a prolonged rainstorm above the 100 year storm levels and the normal waste water levels. Combined sewers meant that all this water was supposed to be treated at the waste water treatment plant. When the flooding reached the facility, the pumps shorted out, as in most large facilities most of the control electronics (there are a lot) are stored in the basement. Electronics underwater rarely fair well, this shut down the entire facility. Large volumes of contaminated water had nowhere else to go and it started covering most of the city. People had anywhere from 4 inches to 6 feet of sewage in their homes.
The city instructed residents not to use water, because all the flushed toilet water was ending up in basements and free flowing in the street. People didn’t stop washing and flushing. Now, when there is sewage everywhere there is a huge need to wash and keep clean. But when all you have is water for hygiene, all that waste will end up in the street or in your basement. So there are strong reasons to use water, and strong reasons not to flush anything down the drain. This is a good reason to have water-less cleaners available for when the waste has nowhere to go. Alternatively it is also a good reason to have short term storage for household waste. There is no point in flushing the toilet if it just ends up in your basement. I would personally deal with twenty feces filled buckets then one flooded basement.
When there is sewage in your house the environment becomes so toxic that even sleeping overnight can cause respiratory illnesses. Any contaminated surface can cause rashes where it makes contact. Bacterial and chemicals in sewage can lead to all sorts of skin conditions. Plus, there will be bacteria everywhere, touch you face or eat without washing your hands properly and you will suffer from diarrhoea, vomiting and fever. The longer it takes before you clean up the mess, the more likely you will get mold. Mold grows FAST in warm, moist, nutrient rich environments. A sewage flooded basement is one of the best environments for mold growth. Mold causes other forms of respiratory illness. The types of illnesses depend on the type of mold you get, and ALL of them are bad.
Clean up of this mess is your first priority, moisture and mold can destroy your home and will destroy the value of your home. The first thing that has to be done if it hasn’t already, is to shut off the electricity to the basement. Water + Electricity + Human + Regional Disaster = Big F#!king Problem. Second thing to do is remove the water, pump it out of the basement and FAR AWAY from the house. Or send the water back into the floor drain if the sewer service has returned to normal. Third thing to do is remove everything from the affected area. Sort all the affected items into two categories, things that can be washed and disinfected into one pile and things that cannot be cleaned into another. A good rule of thumb is if the item is non-porous and non absorbent then it probably can be cleaned. Things like jewelry and solid metal or plastic items can be cleaned. Anything fabric or wooden is toast, THROW AWAY everything that cannot be disinfected. If you aren’t sure if something can be cleaned, throw it away. Clean everything else. Then disinfect it with bleach. Then dry everything before bringing it back into the house.
Now for the structure itself. In a furnished basement all carpet is now ruined, don’t bother cleaning it, I have seen people waste a lot of time and money trying to clean sewage soaked carpets, it is expensive to replace, but you will eventually replace it, everyone does. Many hardwoods and laminate flooring will need to be removed, certain types of sub-flooring will also need to be removed. For peace of mind and ease of cleaning, I personally recommend gutting down to bare concrete floor. Go as close to this as is possible. Replace ALL wet drywall, best to replace the whole panel, but cut at least a foot above the high water mark, you want to expose the entire affected area behind the drywall. The longer you wait to remove the drywall the more likely you will have to remove the whole panel. Underneath the drywall there will be more water damage. Remove any wood that needs to be replaced. Any replaced wood in a basement should be replaced with “blue wood”. It is a chemically treated wood designed to prevent mold growth. It is very similar to the green pressure treated lumber for outdoor use, but it is blue and for indoor use to prevent mold. Any other materials that get replaced try and go as waterproof as possible. Waterproof materials are much more likely to survive future floods.
Use a bleach solution to clean everything. After the bleach cleaning round has dried, spray very affected areas with a mold removal product as the beach contains sodium, and some molds can eat and survive off of sodium. The final step is to fog the entire basement with a mold control product through a fogger machine. Fogger machines can be rented at most tool rental places.
I hope you all never have to experience a sewage filled basement. It can happen when municipal systems fail, or when septic tanks become overloaded. You many not have any notice at all, you might not be at home, or you may be asleep, or it may only take 15 minutes to go from situation normal to SHTF (literally). Once the sewage is in the building, there is a lot of cleanup needed. Anything short of a total cleanup is going to cause long term problems and may even lead to the demolition of your home. Get your house dry, and keep it clean and you will avoid the worst case scenario.