by Cody Lundin
If possible, use plastic bottles made from PET (Poly Ethylene Terephtalate) instead of those made from PVC (Poly Vinyl Chloride). PET bottles provide a greater transmittance of UV radiation as they contain less UV stabilizers, are readily available, and are cheap, durable, and contain fewer additives than bottles made from PVC. PET containers can be distinguished from PVC containers by burning a sample. PET will burn easily, the smell of the smoke is sweet, and the flame goes out slowly. PVC is difficult to burn and the smell of the smoke is strong and nasty. Bottles made with PVC will also have a blueish glimmer.
If you use bottles that are longer than they are wide (soda bottles, for example), be sure to lay the bottles down on their sides, thereby exposing maximal surface area to the sun while creating a minimal amount of water depth. If the bottles are laid onto a reflective/conductive surface such as metal corrugated roofing or some other like surface, the water temperature will be increased. Don't forget about the physics of convection, radiation, and conduction as learned from the shelter chapter. The key to SODIS being effective is maximum ultraviolet radiation, and to a lesser extent, heat. Try whatever types and combinations of reflectors, conductive surfaces, and protection against cooling breezes it takes to maximize radiation and heat into the water, especially in marginal solar gain locales or during the winter. People living in really hot climates should watch out that the bottles don't start to deform from too much heat. Desert ground temperatures exposed to summer sun, let alone metal, can reach more than 140 degrees F (60 degrees C). Each year, Phoenix, Arizona, has several contests where gung-ho participants see who can cook an egg on the pavement the quickest. Experiment in your locality to see what works.
When the bottle(s) are filled with water, place them on a surface that will get full sun during the hours needed for treatment. Avoid areas that will become partially shaded at some point during the day. Southern exposure niches for the top half of the planet work well at having the most available sunshine during the winter months. Protect the bottles from cooler convective breezes and enhance reflective radiation if necessary. Do NOT place the bottles on flammable materials such as grass, cloth, straw, or hay, thinking you'll insulate the bottle from heat loss. The water in clear bottles can condense the sun's rays like a magnifying glass and quickly set fire to combustible surfaces.
What Type of Water Can I Treat with SODIS?
Any microbiologically contaminated water, even water that may have contacted human feces, is suitable for SODIS. The entire purpose of SODIS is to improve the microbiological quality of water through ultraviolet radiation and heat from the sun.
IMPORTANT! Any suspended particulate matter (turbidity or "pond scum") in the water you gather will impede the ability for sunlight to fully penetrate the water in the bottle, thereby reducing UV irradiation and how hot it will get. Water put into treatment bottles should be as clear as possible. Filter the water through coffee filters, a clean cloth, or a bandana to remove any floaters and particulate matter from the water. Nonpotable water can also be left to sit for several hours in a larger container to let particulate matter sink to the bottom and/or be skimmed off the top. On the SODIS Web site, they offer a test that will tell you if the water has too much turbidity to be used without filtering first. They recommend you fill the bottle with the water in question and put the bottle on top of a piece of paper with words that have letters about 3/4 inch high (1.5 centimeters). Next, with the lid off, look down through the bottle to the paper at the bottom and see if you can read the words through the water. If you can, the water is ready to treat with no need for filtering. Water treated with SODIS also tastes good, as oxygen levels within the water are not reduced, as they are with boiled water. After the water has been treated, don't make the mistake of pouring it into "dirty" containers that will recontaminate the water!
Oxygen is important for killing waterborne pathogens, as sunlight forms highly reactive molecules such as free radical oxygen and hydrogen peroxide that help in their destruction. The earlier SODIS method involved shaking the partially filled bottle vigorously to aerate the water before filling the bottle fully and setting it in the sun. Further research has determined that under normal conditions, water from creeks, wells, ponds, and rivers contain more than three milligrams of oxygen per quart, which is more than sufficient to get the job done without further aeration.
Water that has been contaminated with chemicals or pesticides should not be used, as solar radiation will do nothing to remove the contaminants. For this problem refer back to filtration and distillation.
Optimal Climate and Weather for SODIS
The SODIS method requires UV radiation and elevated temperatures to work. For the "techies," sunlight with wavelengths of 315–400 nanometers (nm) on the ultraviolet range of the electromagnetic spectrum are most effective at destroying bacteria (of which colorless plastic or glass excel at transmitting). To treat your water, expose the bottles to direct sunlight for at least six hours if the sky is cloud free and totally clear, to up to 50 percent cloud cover. Although not recommended by SODIS, if the sky is "50 percent" cloudy, I would increase the time that the bottles sit by an hour or two or more (why not?). If the sky has 100 percent cloud cover, UV intensity is cut to 30 percent or less and the bottles should be exposed to the "sun" for two consecutive days. During days of continuous rain, don't use SODIS, as it's not reliable. But who cares, get out there and gather the rain! In regard to the water temperature, the SODIS people claim that if the water reaches at least 122 degrees F (50 degrees C) for one hour it's pasteurized and ready to drink. The locations where SODIS is most effective lie between the latitudes of 15°N/ S and 35°N/ S, the latter being the best—areas of semiarid land with high solar radiation, limited cloud cover and rain, and 3000 hours of sunshine per year on average. The second best location is between the equator and latitude 15°N/ S.
SODIS does have a few limitations. It doesn't work for treating large amounts of water in one container and it requires suitable weather conditions (high solar radiation) for effectiveness. While you folks in Washington state and Maine might be out of luck, you all have an abundance of firewood, so boil away. People in desert regions oftentimes lack the needed fuel resources, so it all works out in the end.
Disinfecting Your Family's Water: One Super Sacred Responsibility
No water disinfection method is perfect. With all disinfection methods, always err on the side of being conservative. The ten minutes you refused to wait for your water to properly disinfect, or got lazy with your boiling, could cost you days or weeks of unnecessary time on and around the toilet. If you're in the middle of disinfecting water with halogens, get distracted from the job, and when you return can't remember which containers are safe to drink, disinfect the entire batch over again. You might invent some way to clearly mark the containers that have been disinfected with colored tape, string, or another method. The person or persons responsible for disinfecting the family's water should take their job very seriously. Screw up with this one, especially with limited medical help after a crisis, and you could help slowly kill a loved one with dysentery.
Finding Emergency Water in an Urban/Suburban Setting
"THESE ARE UGLY DECISIONS, BUT YOU EITHER DRINK WATER OR YOU DIE."
—PETER BEATTIE, PREMIER OF QUEENSLAND, AUSTRALIA, ANNOUNCING THAT DUE TO THE COUNTRY'S WORST DROUGHT ON RECORD, THE STATE WOULD START USING DRINKING WATER CONTAINING RECYCLED SEWAGE WATER
If your home front runs dry, there are several places to look for water in an urban setting. Now that you know how to disinfect the stuff, you must broaden your views about drinking water that, before the disaster happened, you wouldn't have gone swimming in, let alone drink. A point that needs to be clarified about most of the disinfection methods we have talked about so far is that they are for killing organic, living, waterborne pathogens. Contaminants from chemicals and pollutants will be very common in urban and suburban water sources, and boiling, iodine, and chlorine bleach will not remove them! If
ingested, any of these contaminants can make you sick, or in concentration, kill you. Only commercial filters specifically stating that they deal with chemical contaminates and/or the distillation method give you a shot at screening out these unwanted particles.
Explore your alternative water options now. The next time you walk, bike, or drive through your neighborhood, keep your eyes open as to what you could use as an emergency water resource. Keep in mind that post-disaster, "public" water resources will become hot spots and magnets for others who may also have run out of water. History has proved that human nature can get ugly during times of crisis so find as many water options as you can. Never put all of your self-reliance eggs into one basket. Remember that water is very heavy at 8.3 pounds per gallon, and moving it around by hand if vehicles are benched due to gas shortages will be a challenge.
The following list highlights water options you may have in your area. I have beaten you over the head for several pages about how important water is to your survival. The ultimate responsibility lies with you about "reconning" or exploring and locating safe water options that you and your family might utilize during troubled times.
Streams
Ahhh, running water! Many of you reading this chapter have been shaking your head in wonder at my fanatical stance on water as you have it running everywhere within your neighborhood. Good for you, for you are truly blessed. Being from the high desert, I can only dream of the luxury you have, but I've seen pictures in magazines.
Streams vary in size from a trickle to a current that would wash away your SUV. If you have a stream winding its way through your community, find out where it starts. How many miles downstream are you from the source? And what exactly, or who, is upstream? Find out now if there's a major (or minor) chemical plant or chicken farm along its banks. During the Bosnian and Croatian conflict, families fled their homes to camp at nearby mountain streams. The families upstream used the stream for everything, including going to the bathroom. Families downstream became ill with dysentery and many babies and young children died as a result of poor sanitation practices. With or without poop in the water, the common assumption that water running briskly over rocks and aquatic plants disinfects itself is utter nonsense.
After reading this book, you will be worlds ahead of the general populace about what is needed to survive a disaster and the responsibility this means to the natural world. But you mustn't assume that the rest of the population won't be shitting in the stream above you; I tell you now that they will be. Our disinfection techniques can deal with those pathogens, but they can't deal with the gene pool dropout who dumps weed killer into the stream in order to create an empty container. Unfortunately, you are at the mercy of your neighbors when dealing with these types of water supplies. Just because the water looks clean doesn't mean that it is. I apologize that I have no way of telling you how to assess the quality of your water from chemicals or pollutants other than many heavily polluted urban streams will have obvious, nasty-looking, multicolored water. Streams and rivers are commonly used as dumping places fostered by our out-of-sight, out-of-mind mentality regarding sanitation. After an extreme disaster, you may see anything and everything floating past your home, dead bodies and all.
Know your stream, and ultimately, your neighbors. For those of you who have been active in your community protecting above-ground water resources and enjoying their beauty, your efforts just may save your life. Treat all above-ground water sources with caution, no matter how pure they seem, and disinfect accordingly. That small, picturesque Rocky Mountain stream running through property where no one lives above you can still have a dead cow or elk decomposing in the middle of it. If you feel good about using your stream for drinking water, follow the before-mentioned water disinfection techniques and keep hydrated.
Rivers
As rivers are basically streams on steroids, and travel farther through more variables of people and places, they are susceptible to more contaminants. While some may argue that the larger volume of water compensates for this—and they're partially correct, remember the "small" dead bird in my "large" water tank?—there is no way to accurately assess this for the common homeowner. Know your river(s), use common sense when gathering water from it, and disinfect the water accordingly.
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A SPECIAL CAUTION ABOUT "HUMAN-MADE" LAKES AND PONDS
I'm not certain why, but man-made ponds are very common in the Southwest desert, especially around golf courses and more affluent communities. Many urban planners, and I use the term "planner" loosely, should be hung by their toes for using scarce water resources for the titillation of their pocketbooks and for the residents who should have remained in Minnesota if seeing surface water is what they crave. These pretend ponds are typically ringed with unsustainable, water-hogging vegetation from grass to weeping willow trees that are unsuited to the climate and ground conditions as well. As these plants would die within weeks without continuous care, cared for they are, and volumes of chemical fertilizers and toxic pesticides are used to keep things looking electric green. The problem this presents should be obvious, as rain runoff and leaching flush these toxins directly and indirectly into the fake pond. If an insane developer's wet dream is on your family's emergency water hit list, pay close attention to the factors just discussed. Golf courses are notorious for dumping extreme amounts of fertilizers and pesticides onto the greens so be forewarned. Although potentially pricey, many towns have water-testing services. Do your homework, make your decision, and disinfect the water the best that you can.
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Natural Lakes and Ponds
Many communities have lakes and ponds within their midst, whether natural or artificial. There are no natural lakes within the entire state of Arizona, and yet we have several "lakes" as the result of the damming of natural rivers and streams, Lake Powell being one of the most massive. If naturally produced, lakes and ponds usually spawn from underground springs, rain runoff, or snowmelt. Where the water comes from and what type of earth it's sitting on will give you general clues as to its potability. There are a few ponds in the West that are contaminated with naturally occurring arsenic from the ground. They're not difficult to spot as they have absolutely no life growing within them, and frequently sport the bones of small mammals on their banks who have attempted to use the toxic tea to slake their thirst.
Due to the fact that the water in lakes and ponds is somewhat stagnant, especially in smaller ponds, the water may have some type of nitrate contamination or be corrupted by organic and inorganic substances from land erosion, the disintegration of minerals, rotting vegetation, and earthborne biological pathogens, as well as the usual industrial chemical pollutants, and microorganisms from animal and human waste. It all depends on the history of your pond or lake, so know the water source as accurately as you can.
Lakes and ponds are not typically used as dumps, as are streams and rivers, because there is no current to take away the offending idiots' refuse, but don't assume there's not something weird under the water ten feet from the bank. No matter how innocent the water looks, disinfect all water for human consumption via the methods described earlier in this chapter.
Fountains, Goldfish Ponds, Wishing Wells, and Other In-town Water Oddities
Urban areas are blessed with many unlikely places to find water. Simply make a mental note of where yours are located, decide whether they would be a likely candidate for consumption after disinfecting, and enjoy.
Random Water Spigots
As a troubled and trashy teen I lived on city streets for a spell and finding water proved to be a challenge. I quickly learned that most urban and suburban buildings have water spigots that can be found at some point around their perimeter. Gas stations, office buildings, department stores, and dozens of other buildings and their owners need water to wash down loading docks, clean supplies and equipment, water ornamental vegetation, etc. Several of these outdoor faucets have their handles removed, as the owners are tired of vagra
nts using their turf as a watering hole. Some of these functionless faucets simply require coaxing from a pair of pliers and you're back in business. Keep in mind that you're technically taking water from someone else, so be discreet, use caution, and watch your back. Since almost all of these spigots are hooked up to municipal water supplies, they should not be depended upon during or after a crisis. CAUTION: The water from some of these spigots may not be potable (or at least that's what you may be told when you wish to fill up a canteen). As with all things improvised, if you find yourself flying by the seat of your pants, assess the priority of your needs while minimizing damaging variables, and keep your attitude positive.
Harvesting Rain
I love collecting rain, especially here in the desert. Harvesting rain, although fairly simple at first glance, is the subject of many books. One can harvest rain by creating swales or "speed bumps" directly on the ground for catching rain runoff for percolation into the earth, thereby creating a water bank for thirsty plants, or harvest rain directly from rooftops, among other places. At minimum, many people in arid parts of the country choose to put a collection container under a gutter or divert gutter water onto needy vegetation.
When catching rain from conventional rooftops, many factors will influence its potability including, but not limited to, the type and cleanliness of the gathering surface, airborne contaminants, and the storage container it's collected in. Certain toxic materials used for roofing may wash off into the storage tank during rainfall. Leaves, dust, bugs, and bird, mouse and rat poop, among other garbage present on your roof, will also wash off into your storage container if roof washers are not employed (various types of roof washers divert the first five or ten gallons of rain into a separate container allowing the roof to wash off with the first part of the rain.) Extreme contaminants in the air (remember toxic rain?) can also be present that would influence your caught water's potability. Of course the most extreme would be radioactive fallout. As already discussed, water must also be stored in the proper container.
