Before you turn on the tap, consider this: only 2.5% of the world’s water is fresh, and of that water, only 0.3% is available from rivers/lakes/reservoirs. (The rest is locked away in polar ice, glaciers, or soil moisture.) Furthermore, pollution threatens even these scarce freshwater sources. Thus, with our backs approaching the proverbial wall, we have begun to seek sustainable alternatives. One resource seems almost too obvious: rainwater.
Harvesting rainwater requires a fairly simple system:
- a roof (or other collection area)
- a conveyance system of gutters/piping
- a filtering device
- a storage tank
- some sort of redistribution system
Calculating a building’s potential for harvesting rainwater is also fairly straightforward:
Collection Area (sq. ft.) x Rainfall (in./yr.) / 12 (in./ft.) = cubic ft. of Water / yr.
(cubic ft./yr. x 7.43 gallons/cubic foot = gallons/yr.)
In some cities, like Portland, Oregon, harvesting rainwater has become part of a growing trend in environmental conservationism. In 1996, urban ecologist innovators Ole and Maitri Ersson introduced a residential rainwater harvesting system that provided enough water (i.e. 27,000 gallons) to keep the couple supplied for nine months out of the year. Station Place, a 13-story housing tower, received a City of Portland BEST Award in 2005 for storm water management; the building fills a 20,000-gallon cistern, adequate to flush up to 76 toilets on seven floors. And at Portland State University, a mixed-use classroom and dormitory building collects rainwater on its roof and plaza and uses that water to irrigate the landscape.
In other locations—like on islands, where fresh water can be scarce or even nonexistent—harvesting rainwater is not just meant to preserve the environment; it is essential for survival. In Bermuda, for instance, every house must be built so that its roof will collect 80% of rainwater. In St. Thomas, US Virgin Islands, each house is required to have a certain roof area and water storage tank capacity, depending upon the number of tenants it contains.
Whether mandated or not, several large non-residential structures around the world have also been designed to harvest rainwater. The 60L Green Building in Melbourne, Australia, is one such building: every year, more 132,000 gallons of rainwater are caught, stored in two tanks on the ground floor, then filtered, sterilized, and sent back to tenants in taps and showers. Likewise, the Ryogoku Kokugikan Sumo-wrestling Arena in Sumida City, Japan uses its 8,400 m2 rooftop to collect rainwater, which is drained into a huge underground storage tank. The water is then used for toilets and air conditioning.
Whether or not you intend to point your drain spouts into rain barrels anytime soon, keep an eye on the news. Because the law may make that decision for you:




While the science of composting (i.e. the combination of microorganisms, unique balance of carbon and nitrogen, and various heat levels required to turn food scraps into fertilizer) has only existed for the past fifty years or so, composting itself has been practice for centuries. Ancient documents such as the Talmud, the Old Testament, and the Bhagavad Gita provide evidence of humans returning waste to the earth, and there are written records of Greeks, Romans, and Chinese doing so, as well.
…Sweden
UCLA is one institution that has taken action. The university recognized that although its labs accounted for only 10% of building space on campus, they used 60% of the campus’s energy. To try and improve this situation, the university created a Laboratory Energy Efficiency Program (LEEP) to encourage conservation. The LEEP website features a number of lab-specific tips, such as keeping fume hoods’ sash heights at 18” when working; however, many of the tips are applicable to any work environment, such as turning off the lights before you leave or using stairs instead of the elevator.
Opting for a glass of soy milk over a glass of cow’s milk might seem like a radical ethical choice, but it’s not a radical dietary one. Choosing to fill a baby’s bottle with soy milk, however, is—and it might be a harmful choice, too.
How much does the power of suggestion effect our health? Could thoughts actually make you sick?
The proper name for this type of high-speed train travel is Maglev—short for Magnetic Levitation. As the name implies, the train’s “flight” is propelled not by wings, but by magnets, which are embedded into the train’s undercarriage. These huge magnets are then repelled by a magnetized aluminum coil running along the track (called a “guideway”), which is what causes the train to “float” 1-10 cm above the guideway. To propel the train forward, coils embedded into the walls around the guideway are charged with electric current to create alternating polarity. This generates an attractive magnetic field at front end of the train, pulling it forward, and a repulsive field behind the train, adding thrust.
Pitcher filters work by running water through a porous carbon sheet. The sheet acts as a sieve, catching and filtering larger particulate matter. Then, chemical and organic pollutants such as chlorine and pesticides bond with the carbon and, thus, are removed from the water. Meanwhile, ion resin beads filter out metals such as copper and lead by attracting the metals and releasing H+ or Na+ ions “in exchange.” The result is purer H20.
