Can rainwater from rainwater tanks be made safe to drink?

Rainwater from your rain water tanks can indeed be used for potable purposes. However, although rainwater is usually pure before reaching the rooftop or collection surface, it may become contaminated by the time it reaches your rainwater tank. The article below describes possible contaminants and what should be done to make rainwater safe to drink.

Can rainwater be made safe to drink? Yes. How safe? As safe as your well or tap water. How do you make it safe for indoor use? By filtering and purifying it.

Contaminants in rainwater may include algae, air pollution, bird excrement, and leaves, sand, and dust. Local wells have dealt with these problems for decades. Installation of filtration and purification equipment can remove these contaminants at home as well.

First, take measures to keep foreign matter out of the incoming rainwater. First flush devices, gutter screens and other screening mechanisms keep the rainwater as clean as possible before it enters the conveyance system and rainwater tanks. Using screens and filters will greatly reduce maintenance and lengthen the life of the pump and filtration/purification system.

Even the best screening systems will allow unwanted particulates into the cistern or water tank. To keep sediment where it belongs, at the bottom of your water tank, screen incoming rainwater, give the remaining sediment time to settle, avoid disturbing it, and don’t pull water from the bottom of the water tank. Use a floating filter, which extracts water from the middle of the water tank, leaving sediment undisturbed.

Next is filtration, which removes debris from the water. Disinfection or purification follows, which kills contaminants and removes harmful substances that may be present.

To determine what type of system you need, test the rainwater at a reliable laboratory. Without testing, you could spend a lot of money on equipment that will not give you safe water.

Filtration is included in every system, even simple irrigation systems. Examples of filtration systems include: screen filters, paper filters, and carbon or charcoal filters.

Almost all systems use multiple filters. For example, after gutter screens and/or a first flush device, a system often includes two in-line filters of increasing fineness, a carbon filter and a UV light. Each of these should be researched to assist you in evaluating what might be the right alternative for your planned water use and required water quality.

In starting to evaluate filter options, it is imperative to know exactly what the filter system you select will actually remove from the water. National Sanitation Foundation/American National Standards Institutions (NSF/ANSI) standards are the best, most stringent in the industry. Almost all water-filtration products are certified under NSF Standard 61 for Drinking Water System Components. But the critical standards for contaminant removal are Standard 42, “Drinking Water Treatment Units – Aesthetic Effects,” and Standard 53, “Drinking Water Treatment Units – Health Effects.”

Standard 42 covers specific aesthetic contaminants (chlorine taste and odour, and visible particulates). Standard 53 covers health-related contaminants, such as Cryptosporidium, Giardia, lead, and volatile organic chemicals that may be present in drinking water. Systems that meet both of these standards are available, but expensive. Fortunately, the NSF website provides an easy way to search for units made by a specific manufacturer or that remove a specific contaminant. 

Source: HarvestH2o (Excerpts)

An important aspect of ensuring rainwater is safe to drink is to ensure that the water tanks that store the rainwater are certified for containing water for human consumption. All polyethylene or ‘plastic’ water tanks manufactured by JoJo Tanks are certified food-grade and they also have an inner black lining that inhibits algae growth and keeps stored water fresher for longer. Click on the links below to view the various JoJo water tanks, chemical tanks, underground tanks, silo tanks, septic tanks, tank stands and other high quality JoJo Tanks products available in South Africa.

JoJo Tanks South Africa offer a wide range of products such as plastic water tanks and chemical tanks to suit every household, business or agricultural need, including silo tanks and silo tank stands as well as other high quality JoJo Tanks products.  See JoJo Tanks’ VERTICAL TANKS, HORIZONTAL TANKS (transporter tanks), STEEL TANK STANDS and OTHER JOJO PRODUCTS and see JoJo Tanks’ NEW 6000 LITRE UNDERGROUND TANKS. Also see our FAQ and WATER TANK PRICES.