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How Clean Is Your Drinking water?

Jan 16


Do you Filter?

When you go to the supermarket, or fill up your car with gas, what do you think about as you approach the pump? Do you ever think about whether or not your gasoline is clean and pure? Or how it will affect your engine over time? Chances are, no. Even though gasoline makes up a huge portion of Americans' daily lives (transportation: 38%, home energy: 21%), we don't really worry too much about its quality and safety.

What about water, then? If we're so worried about our gas supply, why wouldn't we be just as concerned with our drinking supply? While most people would agree that bottled water at least seems cleaner than public tap water because it's usually packaged in clear bottles--which exposes it to less sunlight and less of a chance to pick up impurities--it is still not as clean as it could be. Does your Keurig coffee, not taste as good as it should?

So, what's the solution? Water filters and filtration systems for home use. They're great ways to filter out contaminants, like lead and mercury, that usually end up in your drinking water after several trips through public water treatment facilities (no matter whether or not you live in a big city or small town). Usually water will go through four total stages of filtration before finally reaching your tap: pre-filtration, coarse filtration, fine filtration, and disinfection. Let's take a look at how these techniques work:

Pre-Filtration: Pre-filtration is a necessary step in filtration because it gets rid of things like dirt and rust. These substances make the water less effective for either human use, or simply clogs up pipes--which can cause damage to both machinery and water systems alike if they're not removed early on in the process.


Coarse Filtration: Coarse filters are used to remove larger contaminants from water, such as decaying plant materials and other silt. Fine Filtration: Finally, the fine filters come next. They act as little strainers that catch microscopic particles, including bacteria which might be found in public sources of drinking water following heavy rainfalls (when runoff picks up bacteria, etc.), or even chemical toxins sometimes found near landfill sites (which seep into groundwater and thus into water sources that draw from them).


Disinfection: Finally, sometimes even with the use of fine filters, some contaminants might still remain in your drinking water. This is when disinfection occurs--a final step to purify your water for consumption.

There are three types of commonly used disinfectants:

chlorine, ultraviolet light, and ozone. Chlorine is the most common type because it's inexpensive, easy to find in stores (as household bleach), and easily mixed with water. When chlorine mixes with bacteria in your drinking water, it forms hypochlorous acid which kills any harmful microbes that might be found there. Some drawbacks to using chlorine as a disinfectant include that it reacts poorly with organic matter (like dirt or plant material), it makes your water have a bitter taste, and another byproduct of its reactions with other matter is the formation of carcinogens called trihalomethanes.

Ultraviolet light is very effective at killing bacteria because UV light damages bacteria cells' chemical bonds. This causes their structural molecules to break down so much that they can no longer function properly. The one drawback to using this method for disinfection is that all the used UV lamps must be replaced at least once every year or two (depending on usage) and specialized equipment well as specialized training for workers may be needed to produce them correctly. Ozone, however, combines oxygen and another highly reactive form of oxygen (called an excited state) in order to kill microorganisms like those found in water. Ozone can be made through either electrical discharges or by bubbling an oxygen-rich gas through cold, highly pure water. Then, ozone is produced when this happens. Another benefit to using ozone as your disinfectant is that it's non-toxic and leaves no residue once the water passes through it--unlike reagents like chlorine which require flushing out of pipes afterwards.

The Future?

It's possible that nanofiltration might play a role in the future for drinking water treatment, particularly when concerning contaminants like lead and mercury. This process involves passing contaminated fluid between two sheets of semi-permeable membrane so that only clean water comes out on the other side while solids are left behind in the filter.

What You Can Do:

If you're interested in improving water quality and think that the filtration, treatment, and disinfection process works pretty well for you right now, then there's no need to worry. However, if you're concerned about your drinking water and want to ensure it's safe before consuming it, there are a few steps you can take on your own to verify its quality. These include ensuring proper drainage when showering or flushing your toilet (so as not to send contaminants from these activities directly into sewers), using filters at home or work which should provide cleaner water than alternative sources like bottled water, and making sure the source of your regular drinking water is known--and either finding out through closer investigation how it's treated or choosing a different source, if necessary