The ultimate guide to water contamination and purification

Note: This article covers not only the types of contaminates you may face but also several purification methods.

Treating your water

The same bleach used to clean your containers can also be used to treat your water and secure its shelf life. You should only have to do this if your water comes from an untreated source such as a well or water from a rural township.

Most cities pre-treat their water so it would be unnecessary to follow this step if you live in a city where water is pretreated. If you simply do not know whether or not the water is treated an additional pretreatment will not compromise your potable water, it may however leave a funny taste in your mouth.

If you are using large water storage containers such as 250 gallon super tankers then it may be a good idea to treat your water with a concentrated water preserver such as Mayday Industries 55 Gallon Water Preserver. There are many readily available. They can be added to your water to increase its shelf life for up to 5 years. This product is made from stabilized sodium hypochlorite (bleach) to keep microorganisms at bay and your water potable. If you are using smaller drums or containers this option could be ruled out as it should not be all that hard to cycle out your containers with fresh water every 6 months.  Another amazing method would be to use Calcium Hypochlorite to disinfect your drinking water. I highly recommend it.

While reading this article on water contamination and purification it wouldn’t hurt you to read a previous article in regard to water sanitation and hygiene in a disaster scenario, how to properly add up your families water needs as well as some basic water storage guidelines.

Contamination possibilities

Just because water looks clean or tastes good doesn’t make it clear of contaminants. Taking a sip from a nearby stream during a hike is a thing of the past for most. The Environmental Protection Agency (EPA) has estimated figures of 90% of the earths drinking water being contaminated and therefore unsuitable for drinking without prior purification.

The same line of thinking goes for ice, which is known to house forms of salmonella, cryptosporidium, and hepatitis for months. As scary as this sounds the Center for Disease and Control (CDC) has estimated that 88% of the worlds cases of diarrhea stem from consuming contaminated water, poor hygiene and improper sanitation. Scarier yet is the fact that one of the worlds deadliest killers is water related illness, causing the death of 1.5 million people annually, the majority being children.

There are six water contaminants recognized by the EPA as seen below.

1. Disinfectants
2. Organic Chemicals
3. Inorganic Chemicals
4. Pathogens
5. Radionuclides
6. Disinfection byproducts

Branching out further from this list, the EPA has a sub listing of a long line of contaminates as well as each contaminates respected level allowed in our drinking water before deeming the water unsafe to consume. Also working side by side with the EPA, the National Sanitation Foundation (NSF) certifies that water filters we use in fact filter contaminants to that specific level as given by the NSF.

In order for the NSF to test the filters level of effectiveness, they add an influent and then measure the effluent. In layman’s terms, the NSF starts with potable water, adds a contaminate, passing the then contaminated water through the filter to test the new level of contamination that resides in the water. In order for the filter to pass NSF standards and become certified it must meet or beat the NSF requirements. Why do we need to know this? Because we one day may wish to purchase a water filter.

It would be wise to compare the safe levels of drinking water standards as set up by the EPA & NSF. For example:

The EPA requires drinking water contain less than 0.0015 mg/l of lead, whereas NSF certification requires water contaminated with 0.15 mg/l of lead be reduced down to 0.001 mg/l of lead, a 93% removal. The EPA and NSF requirements work well alongside each other. lets move on.

Pathogens

Pathogens. In other words: parasites, viruses & bacteria. Pathogens are living microscopic organism which include Bacteria, parasitic worms, fungi, protozoa and viruses. Visit the CDC’S website for more detailed information on the many different water contaminates while we cover the general bulk.

Parasites

These include worms, ice and protozoa. While all three of these parasites can be transmitted through water, protozoa poses the greatest threat. Protozoa comes from human or animal feces waste. These protozoa are single celled organisms which may have more than one nucleus. Usually they can be found in water and cause serious gastrointestinal illness. Sizes are between 2 and 30 microns.

A micron is 1/1,000,000 of a meter. While this sound very small for a parasite, any quality of water filter (with a pore size smaller than 1 micron) can remove these easily enough.

Bacteria

Bacteria are microorganisms, single celled and with one nucleus. They grow in fresh water, sea water and soil and are found in every habitat. They measure between 0.2 and 4 microns in size. Some bacteria provide health benefits and many others are not harmful at all. One teaspoon of fresh water carries an average of 5 million bacteria cells.

Many other  bacteria unfortunately are harmful.  While some of the larger bacteria are easily removed by water filters bacteria smaller in size can be difficult to detect and remove.  A lot of the bacteria found in water is the result of fecal waste contamination, and can also cause severe gastrointestinal illness, among other infections.

Viruses

Viruses evade healthy cells and inject their genetic makeup into them, transforming them and then multiplying in number. If one were to consume water compromised by virus symptoms could include weakness, illness, fever, liver disease, gastrointestinal illness and paralysis.

Due to the small size in viri many water filters are unable to effectively remove viruses.  They usually range between 0.004 to 0.3 microns. Some filters claim to remove them. SureAqua Survival Straw Water Purification filter is one of them.

Microorganisms are of many different sizes depending on variable conditions in which they grow so you may find conflicting data regarding size depending on where you look. No matter the contaminate type, for your conventional filter to remove it correctly the absolute pore size must be smaller than the contaminant it is attempting to filter.

So how should you decide if a filter will remove a pathogen of a specific type? Simply review the test data of the filter you are inquiring about. Certified filters provide detailed information in regard to the filters performance.

Organic and Inorganic chemicals

Your drinking water may be contaminated by several organic and inorganic chemicals which the EPA does test for. Chemicals ruch as the ones released from factories such as plastic, metal, coal-burning, erosion of natural deposits, corrosion from plumbing and others .

The human bodies system and organs can face damage and cancer can be caused from consuming chemical contaminates. While many conventional membrane filters fail at removing chemicals, reverse osmosis and distillation have been proven to be effective options for treating chemically contaminated water.

Byproducts and disinfectants

Disinfectants in this case are chemicals added to our drinking water during purification to help destroy dangerous microbes we may otherwise consume. Disinfectants such as these consist of chlorine, chlorine dioxide and chloramines.

During the water treatment stage byproducts can also be created and consuming high levels of these heightens the risk of not only cancer but kidney, liver and neurological disorders. Byproducts such as these consist of haloacetic acids, chlorite and bromate. Have no fear however as these by products and disinfectants are usually eliminated before drinking contaminated water with a high quality carbon water filter.

Radionuclides

Radionuclides, in other words, radioactive contamination. Drinking water in the United States has 1,000 levels of radioactive contamination present. Most of the radionuclides present are from the erosion of natural mineral deposits. Another way radioactive contamination can affect drinking water is from improper disposal or accidental spills of human made nuclear materials such as uranium, radium and other alpha/beta particles. Long term exposure leads to an increased risk of cancer, while uranium tainted drinking water also causes kidney damage.

Traditional membrane filters do not remove radionuclides. Reverse osmosis, lime softening and ion exchange devices however have been shown to reduce the level of present radionuclides.

Local levels

One rather important thing you could do today is educate yourself on your local water sources and the levels of contaminates in it that are exposed to you and your family. To do this visit the EPA’s website (epa.gov/safewater) and then locate the link to your area. If your water source does not report its findings to the EPA you would do well to contact your local water provider to request a report.

You should be informed of the purity of your drinking water and correct it if your water source falls short of EPA guidelines. In a true time of crisis water quality could go from good to bad overnight. or even shut off entirely. You need a thorough water plan and the foresight to prepare your family to stave off a potential disaster.

Purification Methods!

Not everyone has access to a private underground well or a large storage cache of clear drinking water. With that said you will likely need to purify water from sources you have access to, which very well may be nonpotable during your time of need. There are six steps in regard to large scale water treatment that are followed by water treatment facilities.

1. Pretreatment – Screen for large debri, early chlorination
2. Adjust the PH – Alkaline & acid adjustment
3. Coagulation sedimentation particle removal
4. Filter – Small particle removal
5. Disinfect – Eliminate pathogens with UV light & chemicals
6. Extra treatment – Radium removal, fluoridation and hard / soft adjustment

You obviously should not copy these steps every time you want potable water as it is just not practical for you and your family and can also be very expensive. The objective above however is still the same – screen and filter debris and eliminate the impurities. Properly making non potable water safe to consume and use is our primary objective. Over the next section we will learn how to properly do so and debunk the worries associated with the process.

There are pros and cons to all and all can be used in conjunction with one another or be used  stand alone.

-Boil
-Filter / Purify
-Distillation
-Reverse Osmosis
-Chemical disinfection
-UV light

Boiling

While not always the most convenient or accessible, boiling water is the ideal way to clear microorganisms from your drinking water. Keep in mind that while boiling water eradicates all types of pathogens it does not improve the taste of the water and it will not remove chemical impurities or particulates. When bringing water to the boiling point (212 0f) microorganisms are destroyed.

You may have read that it is necessary to boil water for a duration of 10-30 minutes before safely consuming but this is simply not true. After letting your water reach a boil for one minute, drinking should be acceptable. Just make sure to let it cool naturally, not only to avoid burning your mouth but to also ensure the water remains at its required high temperature for the proper duration of time.

This method while preferred for purifying clear water such as pathogen infected tap water is slow and does require a source for heat. This method is also not recommended for purifying water from lakes or other natural sources as it will not remove any debris or particulates.

Purifying / Filtering

There are several levels of filtering water. Some are as primitive as passing water through a swatch of cloth to screen debris, or as sophisticated as passing it through a portal so tight that nothing next to water molecules can push through. Many times both methods are used in conjunction with one another.

For instance, water being cleaned from an all natural source such as a lake, stream or river is usually filtered in several steps. Initially a rough filter, such as a towel or handkerchief is used to remove debris and dirt, followed by a fine filter to remove smaller pathogens.  The point is to remove as much gunk from the water as we can before purifying it.  The process also saves the filter from any potential glogs the debris may cause otherwise.

Retailers use the terms “filter” and “purified” loosely and interchangeably when in fact they refer to very different things.  “Filter” is a very broad definition  used to describe any device which has the ability to remove contaminants from water. This could be as basic as a coffee filter, however filters usually have a fine membrane. Many water filters remove protozoa and different types of bacteria. To debunk another common belief, they DO NOT remove salt, heavy metals or even minerals.

Now a water “purifier” on the other hand is a special style of filter defined by the EPA as something that can reduce all pathogens to safe levels, removing 99.9% of cryptosporidium, 99.9% of all viruses, and 99.9999% of all bacteria, Many purifiers labeled as certified offer general and broad protection from water based contaminants.

There are three categories of water filters:

• POE (Point of Entry)
• POU (Point of Use)
• Portable

To use a POE style filter you would hook it up to your main water line entry point, thus filtering the water running through your entire house. A POU filter is one that sits under the sink, in a countertop or directly at the end of a tap filtering only one tap. Lastly we have portable filters. Portable filters are light in weight as to be easily carried and are either gravity fed or driven by a pump. Often they are found or used when camping, hiking or traveling. They come in many shapes and sizes and can even take the form of a pitcher of water.

Even if your cities water has been compromised a quality POE filtration system can ensure safe drinking water long after contamination. Now if your water service is ever shut off or rendered inoperable an alternative water source would be necessary, making a POE or POU useless. In this case a gravity or pump based filter is needed.

The most important thing you can take into consideration when selecting a POE or POU is the pore size. Selecting a filter with an absolute pore size of 1 micron or less ensures anything larger than 1 micron is rejected. This safely removes ALL protozoa as well as protection from quite a few bacteria sources as well. Virii however are much smaller than 1 micron and can easily pass through.True all in one water filters that eliminate all pathogens (bacteria, protozoa and viruses) without the use of chemical disinfectants do exist and they are usually labeled as “water purifiers”.

Chemical Disinfection

A very common way for water to be treated and cleaned free of pathogens is chemical disinfection.  Iodine and chlorine are the most commonly used. A popular product is Potable Aqua Water Treatment Tablets. Most of the tablets have a shelf life of 4+ years if unopened. Another option is Katadyn Micropur MP1 Water Purification Tablets.

Household bleach is an excellent alternative if you have exhausted other options or have no other means. Bleach is just as effective as any other chemical disinfected product, its only drawback is its shelf life. A mere 6 months before potency starts to decline with bleach.

Electromagnetic chemicals known as halogen disinfectant are very effective in eliminating bacteria and fairly effective in combating viruses. Protozoa however is not destroyed by halogen type disinfectants as protozoa are coated with protective barriers immune to the halogen treatment.

Dosing

There may come a time when your only dosing options are to use bleach or iodine to disinfect your water. If commercial chemical disinfection is required I suggest Mayday Industries 55 Gallon Water Preserver.  Suggested dosages are marked on the package.

The table below breaks down the recommended dosages for disinfecting water that is clear or cloudy using bleach or iodine. To dose water with iodine the recommended dose is 5 drops per quart of water, or 5 parts per million. Bleach is 2 drops per quart, or 5-6 parts per million. These figures assume a bleach solution with 5-6% sodium hypochlorite or iodine, with a 2% tincture iodine solution is being used. After the solution is applied let the water sit covered for a half an hour. After the halogen runs its course the water should smell of chlorine or iodine. Also the cloudier or turbid the water, the higher the dose of chemical disinfectant needed

A double dose however leaves a stronger chemical taste and using iodine to disinfect for prolonged periods of time  is not recommended for people with thyroid problems, pregnant women or anyone known with hypersensitivity to iodine. An alternative to using stronger doses would be to simply filter the water first to clear it followed by the standard dose of halogen. Lastly you could use the double dose and then small-pore filter to remove a majority of the chemical taste.

It is said to also double the dose of chemical infectants when disinfecting very cold water (water below 40 °F) as the halogen reaction time is reduced. Optionally you could just wait until the water warms before treating it. Secondly you can wait two hours instead of the standard 30 minutes for the disinfectant to run its course.

A common complaint and drawback to using chemical disinfectants is the smell and taste of the treated water. To combat this there are several options, some as follows:

1. Use a filter to aid the chemical disinfection process
2. Purify the water first or allow the disinfectant to work longer, you can avoid using higher doses
3. Air out treated water for a few hours before drinking
4. Mix a powdered drink mix, preferably something fortified with Vitamin C. The ascorbic acid (vitamin C) helps convert the iodine & chlorine to a tasteless form.

Try out several methods and figure out a course of action that works bests for you and your family.

Distillation

This is the process of boiling water and then collecting its vapor as it condenses. This is a highly effective way of purifying water as it removed all pathogens and chemical contaminants. It is commonly believed collectively that distillation & reverse osmosis are the most effective at cleaning drinking water all aboard.

One drawback that may have many opt out of distillation is that the process is very slow. Think 6 hours for an average of 1 gallon of water. Very slow. They also require the use of electricity. Coupled together the long process may not be practical to use under various disaster situations.

Reverse Osmosis

Flowing water from a low concentration level to a high one is known as reverse osmosis. Think about how someone may die simply by drinking seawater. Well the seawater in your system actually draws water out of your body as it is trying to dilute the high concentration of salt, eventually killing its host from dehydration. Well reverse osmosis is exactly the opposite. It is the process of flowing water from a high concentrate to a low. This can be quite the process. Water is pressurized and forced through a very fine membrane while the excess water and concentrate (pollutants) are discharged by forcing untreated water molecules through a semipermeable membrane or filter.  This happens in several stages and ultimately reaches a storage tank.

While these systems do an amazing job at removing all types of pathogens and impurities they also require very high water pressure (>740 psi) and may also require the use of a specialized pump to boost your home’s psi. A secondary thought would be water waste. Only 5 – 10% of incoming water is collected as pure. The remaining 90 – 95% is flushed away as a pollutant. Think about treating 8 – 10 gallons of water to create only 1 gallon of purified water to put the waste at better perspective. The filters can also be expensive or non existent in a time of need and also need replacing yearly.

Ultraviolet Light

Disinfecting water using ultraviolet (UV) light has been a method in use for many years by large scale water treatment facilities and is now becoming readily available for the home user, traveler or hiker. One of the best on the market is the Viqua TrojanUVMax Ultraviolet Light Water Disinfection System.

Using these portable devices can be quick and effortless taking only a couple of minutes at most and has been proven to be effective at removing all types of pathogens. The microbes DNA is disrupted by the UV light, preventing them from multiplying. Protozoa is also neutralized under UV light.

Unfortunately (UV) will not help the water to taste better or remove impurities such as chemicals, particulates or dirt.

I hope this helps and this also wraps up our month long write up on water. Sometime soon I need to put all of the articles in relation to water together!

Cover Image by שי קסל