Setting Up an Easy to Build Rainwater Harvesting System with a Tin Roof, Rain Gutters, Screens, Chlorine Tablets, Storage Tanks and an Activated Carbon Filter to Ensure Safe, Clean Drinking Water
By Markerbuoy – On Canada’s Left Coast
Canada – Almost twenty years ago, I set up this rainwater collection system out in the woods. Using about three hundred square feet of metal roofing to catch the rainwater, the water is run through a very coarse filter as it exits the gutter.
Before flowing in to the 2,000 gallon storage tank, the water passes through a much finer filter and is chlorinated at the same time, using a slow dissolving chlorine puck normally used in pools and spas.
Thus the collected water is cleansed of debris and other nasty stuff before it enters the storage tank. This, I think is key to successful acquisition and storage of rainwater. If the water is not clean before entering storage you are making extra work for yourself “downstream”, assuming you intend to drink it. I have never had to clean the inside of the tank (which can be a dangerous job) or been afraid to drink the water after final treatment and filtration.
Of note, is the fact that the tank is pigmented (green in this case), which helps prevent sunlight activating growth of any kind in the precious water. White or clear tanks are not so great for blocking the harmful effects of sunlight. During warm weather I monitor the chlorine content of the stored water.
With regards to chlorination of water, ScientificAmerican.com states, “Chlorine effectively kills a large variety of microbial water-borne pathogens, including those that can cause typhoid fever, dysentery, cholera and Legionnaires’ disease. Chlorine is widely credited with virtually eliminating outbreaks of water-borne disease in the United States and other developed countries.”
In addition, Life Magazine recently cited the filtration of drinking water and use of chlorine as “Probably the most significant public health advance of the millennium.”
It only takes a cupful of household bleach to effectively “shock” the water free of most pathogens. I usually do this on departure from the cabin and the residual chlorine then has time to dissipate prior to our return. In case there is any residual chlorine in the supply, I again filter the water before use, using an activated charcoal cartridge in my Rainfresh household water filter.
The result is a reliable source of fresh clean drinking water that literally falls out of the sky! No need to drill a well or construct unnecessarily complicated systems, electrical or otherwise.
The whole system runs on gravity; the storage tank is approximately 100′ higher than the cabin.
For every foot of elevation, water pressure below rises by .43 pounds per square inch, resulting in about 43 psi at the cabin level. The pressure is entirely sufficient to run the filtration system, a propane fired demand hot water heater and a hosepipe – all the water amenities of living in town.
Of course, with even a simple system such as this, some degree of maintenance is required. After all, you are running a small utility. Perhaps the biggest concern comes during the winter months, which in our part of the northern hemisphere can become freezing cold at times, potentially causing burst pipes, valves and filter bowls, if they are not properly drained in the fall.
In the woods, tree debris falls on the roof and despite best efforts, gutters always clog too quickly. Water filters have to be exchanged once in a while and attention has to be paid to chlorination. However, basic maintenance is a small price to pay for such a life sustaining benefit.
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