Water Survival During the Zombie Apocalypse

First off a bit of a disclaimer, I am fully aware that zombies are not real.  I am however highly entertained by zombies and all things undead.  Since the Omega Man Journal is about water and survival, that lead to the obvious thought experiment of what challenges a zombie outbreak would have on our ability to get safe drinking water.

Zombie, Zombies, Undead, Scary Zombie,

Zombie Rage Face (zombieambience.com)

The first thing to appear after the dead rise will be panic. Fear will be rampant and many people will be operating on their fight or flight instincts others will be holed up at home. This includes the people who work at municipal water treatment plants. Water facilities, although automated still depend heavily on people to operate them. When those people stop going to work or are already zombie chow then the water will stop shortly thereafter. To see what it would look like when a water system gets shut down and roughly how long it would take read Grid Shutdown: How Long Will The Water Last. The same will be true of the sewage systems. Read Grid Shutdown: Why Is There S#!t In My Basement, Sewage Emergency: Thunder Bay Flooding and A City Without Sanitation to see just how disgusting our once clean (or not so clean) cities will become.

Zombie, Horde, Zombie horde, the walking dead, set pictures

Zombie Horde (geektyrant.com)

Speaking of sanitation, people will die from unsanitary conditions. That means dead bodies, not just zombies, but regular dead bodies. Cholera is an excellent example of a waterborne disease that is a direct result of decomposing animal tissues in a water supply. Thirst will drive people to the nearest supply of water, then many will die on the banks and contaminate the lakes and rivers. Remember at this point I’m not talking about zombie contamination of water sources. That’s coming up later. This is a real danger when thirsty people or animals die in water supplies.

Depending on how zombies are created there may be a serious water vulernability. There are already bacteria, viruses, parasites and other micro-organisms that use both water and human bodies as part of their natural life cycle. Typically we call the effect of these micro-organisms “water borne disease”. Also there are already parasites that can take control of other organisms even to the point of making the host suicidal. Specifically there is a fungus that will radically alter the behaviour of ants turning them into zombie ants. (read more about zombie ants).  We are talking about total control of the host for the benefit of the parasite. Finally there are countless micro-organisms and insects that thrive and depend on rotting flesh to survive either for food or as a vital part of a life cycle stage like maggots turning into flies.

Bacteria thrive on and cause decomposition of deceased organic matter

Those three characteristics which already exist, put a zombie making organism on the edge of being possible. Nature has already made all the organisms necessary to create a zombie, luckily for now the necessary skills are in different organisms and target different organisms. The problem is, if nature caused one organism to eat rotting flesh, it can teach another organism to do the same. Same thing with learning to disperse through water and to take control of other organisms.

Zombie Ant With Fungus Growing Out Of Its Head (nationalgeographic.com)

Let’s assume this is the cause of zombification, what then can anyone do to protect themselves? The good news is that modern water treatment is very good at removing and inactivating micro-organisms. The combination of chemically assisted filtration and disinfection should (if done correctly) remove 99.999% of micro-organisms. Depending on the size of this fictitious zombie bug/parasite/virus it might be possible to remove even more than 99.999% if it is on the large end of the size scale. If it is a virus, which is the smallest type of micro-organism then removing 100% of the z-virus will be next to impossible. That means we better hope that there is a disinfection method that can kill the virus either chlorine, UV, ozone or boiling.

Zombies Again (beyondhollywood.com)

One thing many people haven’t thought about when they are talking about zombies and water.  Water is very heavy.  If you have to haul water from its source to your secure facility it will become very difficult to run at the same time.  Now vehicles are an option as are hand carts and if you have the resources pumps and pipes are best.  Just remember that they are all noisier and may attract unwanted attention from nearby zombies.

Those are some of the challenges I see affecting our ability to drink safe potable water in the event of a zombie outbreak.  I tried to be as true to real science as is possible when talking about zombies.  At the very least I hope you were entertained.  Can you think of anything I missed?

How Does A Water Filter Work?

Whether you are building, operating or just buying a water filter, filtration is an essential part of most water treatment processes. Filtration is used in the counter top/faucet filter all the way up to municipal water treatment facilities serving tens of millions of people. Even in emergency and survival situations filtering with a shirt or other cloth is often the first thing recommended for water treatment. A shirt isn’t adequate on its own by a long shot, but it is better than un-filtered/untreated water. Used in conjunction with other water treatment steps, filtration makes the rest of the disinfection process significantly easier and cheaper.

We filter water primarily as part of the disinfection of water. Disinfection is the inactivation and removal of pathogenic organisms. Filtration is part of the removal portion of disinfection. (The other part being settling or clarification).
Filters work to physically remove contaminants from the water. They do this by passing the water through a filter media. The media presents a barrier to solids in the water. They literally collide into each other and become trapped. The media can be made of almost anything. As long as it has the ability to let water through and preventing solids from passing through. The pore size (size of space between the media) dictates the performance of a filter. The smaller the pore size the more that gets removed from the water. That sounds like smaller is better, but small pore sizes reduce the rate you can filter water and the total volume of water you can filter. It is always a trade off between ability to remove contaminants from the water and the ability to filter larger volumes of water.

Below is a diagram of pore sizes and which contaminants can be removed at a given pore size. Filters with smaller pore sizes tend to be more expensive. They require precise manufacturing techniques and maintenance.

Particle Size Diagram And How Fine A Filter Needs To Be To Remove Them

This trade off lead to the development of chemically assisted filtration. The filter media and the water itself is treated with chemicals. The water is treated with chemicals to make the particles in the water larger called floc (large groups of particles stuck together). At the same time the filter media is treated with a chemical to make the media attract and trap the particles in the water. Most chemically assisted media, has a electro-static charge opposite the one in the floc. Typically the media has a positive charge and the floc has a negative charge. Now instead of waiting for the particles to collide with the filter media, the floc is attracted onto the surface of the media (adsorbtion) and into the filter media itself (absorbtion). These types of filter media are said to be activated. Below is a diagram outlining the difference between straight filtration and chemically assisted filtration.

Direct Filtration Versus Chemically Assisted Filtration

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