Filter your own water

Drinking Water: One of the things we take heavily for granted. But do we know how to filter our own water? We rely on a water system that is completely beyond our control. We are lucky if we know where it originates from, let alone what contaminants are present, or how the water is treated, before it comes out of our faucets.
Recently, high levels of nitrates have been found in California drinking water, a result of waste water treatment systems and farm fertilizers contaminating ground water. Intake of nitrates in large amounts have been known to cause "blue baby syndrome" which causes an infants oxygen supply to be cut off. In addition, high levels of nitrates have been linked to certain forms of cancer. Those who live in agricultural areas are more susceptible to a high intake of nitrates, as fertilizers seep into the ground water, and contaminate both municipal water supplies and private wells. While some larger communities have been able to filter nitrates from their drinking water, for the most part, this contaminate spreads unchecked to an increasingly large number of communities throughout California due to lax water filtering regulations.
A few weeks earlier, in Massachusetts, a main water pipeline broke, releasing millions of gallons of water into the Charles river. roughly 30 towns and cities were affected by this leak, causing millions of people to boil their water, as completely unfiltered water ran from their taps. Drinking unfiltered and untreated water would result in diarrhea, nausea, vomiting, and headaches, or worse for those with compromised immune systems. This water leak lasted only four days, long enough for bottled water to become a scarcity, and drinking water a precious commodity (this lasted only four days too).
Putting aside other recent events involving contaminated bodies of salt water, this was enough to convince me that we cannot rely on the powers that be to deliver us with our means of survival. As our nation begins to lack the means of supplying large amounts of safe water to every community, we should take our own initiative to learn how to filter our own water, should we ever need to.
Filtering your water is fairly easy, and requires few supplies, many of which can be found in nature (such as sand and gravel). Knowing how to filter your own water, therefore is not only a handy skill should your water supply become contaminated, but is also great to know for camping purposes, and purifying fresh running water.
You can make a complete filtration system with a variety of supplies. Basically you need two containers (one on top of the other), the top one to hold the dirty water, and the bottom one to hold the filtered water. There is a small hole in the top container which drains the dirty water into the bottom container. In the bottom container are layers of filtering substances, such as charcoal, sand, grit, cotton, fibrous materials, and rocks. These materials should be layered from the coarsest materials to the finest, and then a layer of coarse rocks at the bottom. From the bottom of this bucket a pipe or tube should run out. This acts as a spigot from which clean filtered water will flow.
It might also be a good idea to boil this water, in addition to filtering out any sediment or large matter. This will kill any existing bacteria that were not filtered out by the charcoal.
Follow the link for a more exact, technical explanation of how to filter your own water. It may help you someday, when our current water system cannot.