Decoding Design

Harvesting rainwater for more than greywater

Posting in Cities

Rainwater is in its purest form before it hits the ground, but it is usually collected for non potable uses only. What if that huge, free source of naturally distilled water could be used for drinking and cooking?

Rainwater is in its purest form before it hits the ground, but it is usually collected for non potable uses only. What if that huge, free source of naturally distilled water could be used for drinking and cooking? A simple rain collection module named RainSaucers makes potable rainwater possible.

The RainSaucer, developed by Tom Spargo, decreases the chances of rainwater contamination by decreasing the instances of contact with building surfaces (roof, gutters, downspouts.) Resembling an upside down umbrella, the RainSaucer is made of five components: a food grade polypropylene 'saucer', pipe fitting, mesh filter, fasteners, and a retention ring for wind resistance. The surface of the Saucer harvests 6.75 gallons per inch of rain and can work with any container. By controlling the materials that rain does touch and with the help of a filter, the minimal design provides a straightforward and affordable way to use rain as a clean source of water.

Tom Spargo offered his own thoughts on his design and its implications for issues of water quality and access:

"I came at RWH (rainwater harvesting) from the perspective of trying it make it more scalable. I simply pondered why it is that this great concept isn't more widespread and decided it was too much of a 'project' and not enough of  a 'product.' RainSaucers aims to make RWH a product you can buy in local markets, just like you can buy solar ovens, solar lights, kick pumps, etc. We chose Polypropylene because it is low cost, food grade, FDA approved, and BPA free. This makes sure the water collected is as close to pure natural distilled water as possible. Portability and easy packing were important. So we designed RainSaucers to be able to roll up and unroll for transport or shipping by air. We also made sure no tools were necessary to install; simplicity equates to scalability in our view."

Even more significant than the possible applications in the US is the potential for use in developing countries, where the quality of even city water systems is not trusted. RainSaucers just completed a field trial in Quetzaltenango, Guatemala. The company wanted to help families save money by reducing their dependence on bottled water. The region is served by municipal water but the citizens would rather buy bottled, citing suspicion of bacteria in the water system. The average expenditure in Quetzaltenango on bottled water is $300, or about one month's income, every year. Imagine spending one month’s income on water per year.

Next in sight for RainSaucers is India. Although 18 of India’s 28 states have made rainwater harvesting mandatory, less than half of those required households have complied.

Watch the video of RainSaucers' Guatemala trial below:

Images: RainSaucers

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Sun Kim

Contributing Editor

Contributing Editor Sun Joo Kim is an architect and creative consultant based in Boston. Her projects include design and master planning of museums, public institutions, hospitals, and university buildings across the U.S. She holds a degree from Carnegie Mellon University and is a member of the U.S. Green Building Council. Follow her on Twitter. Disclosure