Saturday, April 19, 2014
Giardia, Cryptosporidium & Other Bad Stuff
Some people think that giardia and cryptosporidium are only found in rivers and lakes in the wilderness. But the bad news is that the worst outbreaks of these water contaminants in the U.S. happen right in our city water supplies.
One of the most memorable outbreaks was in Milwaukee, Wisconsin in 1993. Over the span of two weeks, more than 400,000 residents became sick, and 104 people died from a cryptosporidium outbreak caused by a malfunctioning city water treatment plant.
When the public water supply is contaminated, and the contamination is discovered, a boil order is usually issued by the community health department. A boil order is an advisory telling residents that they need to boil their drinking water to prevent illness.
The illness may be caused by any number of bacteria, virus, or other living organisms that find their way into the public water supply. The causes of contamination can be a natural disaster such as flood, earthquake, landslide, etc. Or it can result from such things as a broken water line, broken sewage lines that permit intermingling of sewage with the community water supply. Or it could be the result of equipment failure in the water treatment or delivery systems.
A boil order usually advises to boil drinking water for one minute. The word boil mean maintaining the water at a rolling boil, with vigorous bubbling for the entire minute. And this should be done to all water that will be use in any aspect of food preparation such as diluting soups or juice concentrates, rehydrating mashed potatoes, mixing gravy, even making ice cubes. This is not just for the water you drink.
Another consideration is that the water you use to wash dishes needs to be clean, or else you risk contaminating the dishes. To help minimize the amount of dish washing that needs to be done, it’s a good idea to have a few days’ supply of paper plates, plastic utensils and cups in your emergency storage. You can use large zip baggies to serve as mixing bowls and storage containers for leftovers. Throw this stuff away after use, conserving your purified water supply for consumption rather than sanitation.
An alternate method to boiling is to bring the water temperature up to more than 165 degrees F and hold it there for six minutes, effectively pasteurizing the water. Use a cooking thermometer to verify that the water temperature is high enough. Pasteurization is a process that you can even do in a solar cooker on a sunny day.
A good filtration system is an excellent way to remove pathogens from the water. A filter rated at .10 microns will stop giardia, cryptosporidium, and bacteria. For versatility and effectiveness, I recommend the Sawyer 3 Water Filter (http://sawyer.com/products/sawyer-3-way-water-filter/) that has a million-gallon guarantee.
Another alternative is to treat water chemically. You can do this by using a mixture of one tablespoon of chlorine bleach per 5 gallons of water. Let it stand for at least 30 minutes before using. But not all organisms will be killed by chlorine, giardia being one example. Iodine is better at inactivating giardia, but iodine causes health problems for some people. Effectiveness of chemical treatment is affected by water temperature, pH level, and clarity. The colder and cloudier the water, the longer it takes for the chemicals to be effective.
Water used for bathing doesn’t usually need to be purified first, but the water used for washing and rinsing hands and face should be sanitized before use. And be careful not to allow contaminated water near open wounds or rashes.
In any survival situation, pure water is a top priority. So make sure you have enough on hand in your emergency supplies to last a couple weeks, and have the ability to purify more water when your supply runs low.