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Recycling Rain

Posted by GBM Research

Mar 18, 2011 11:22:00 AM

WHILE RESIDENTS IN MANY parts of the country have experienced water shortages and droughts over the past few years, they aren’t the only ones who need to worry about conserving water. The fact that water is heavily subsidized means that planning for effective water use now can help your home buyers save money should subsidies be reduced in the future.

“Until now, water has been fairly abundant and reasonably priced, but as the demand increases, especially in heavily populated areas, cheap water will become a thing of the past,” warns John DiTullio, vice president of sales for Cultec, a manufacturer of stormwater management chambers. Homeowners with large or water-intensive landscapes will take a big hit should water prices rise, Fiskars-Rain-Barrelsespecially when you consider that for the average home, up to 40% of the water consumed goes to outdoor use, such as watering lawns and plants. (And approximately half of that water is wasted due to evaporation, misapplication, or overwatering.)

“There is a growing awareness that rainwater harvesting is at least a partial solution for potable, nonpotable, stormwater, and energy challenges. National, state, and local jurisdictions are developing legislation, codes, and ordinances that encourage the practice,” says John Hammerstrom, president of the American Rainwater Catchment Systems Association (ARCSA).

While harvested rainwater has the potential to be used inside the house for a variety of functions such as toilet flushing or laundry, watering the yard is the most common use of it—and largely free of heavy regulation. “For many applications such as irrigation, fire prevention, or additional reserve for exterior cleaning, the reclaimed water may only require very limited treatment,” says DiTullio. “It only makes sense in future designs to capture and reuse this rainwater as opposed to purchasing new water.”

How It Works

Realizing the worth of harvested rain is simple—and so is capturing it. Today’s choices include simple rain barrels, above-ground cisterns, and buried tanks.

If you are considering a rainwater catchment system, first figure out how much water you need to collect. The general rule of thumb is that for every inch of rain that falls on a catchment area of 1,000 square feet (the size of a typical roof), approximately 600 gallons of water can be harvested. In general, your plants need about an inch of rain per week (or approximately a half gallon of water per square foot of garden). If a landscaped area is 100 square feet, you’ll want to have about 50 gallons available on demand.

For smaller amounts of water, a simple rain barrel will do. But for larger amounts of water—1,000 gallons and up—a holding vessel is the best option. The components of a rainwater harvesting system include the following:

  • Roof. Rainwater should only be collected from a roof and stored in a cistern. Runoff from parking areas and other outdoor surfaces could have harsh chemicals and other contaminants.
  • Rainwater conductors. Gutters convey the storm water from the roof to the tank.
  • Cistern. A storage tank that stores the water and allows large particulate matter to settle out of the water.
  • Overflow from cistern. This pipe takes overflow from the cistern to the storm drainage system.
  • Pumping system. Provides the pressure required at the fixture most distant from the tank. > Disinfection system. There is a wide variety of filtration and disinfection systems.
  • Manhole. This provides entry for maintenance.

Once these components are in place, the process is simple: The rainwater runs from the roof, through the gutters and downspouts, and into the cistern. The water passes through a screen or other filter, which takes out large debris. A variety of pump systems can be used to retrieve the water from the storage tank. Cisterns should be protected from direct sunlight to prevent the growth of algae and other microorganisms. They should be equipped with overflow pipes, and rainwater overflow should be piped to the storm system.

Which Type?

  Above-ground cisterns can be attractive (or, if they aren’t, hidden by some type of screening). In many areas of the country where it’s difficult to dig, these vessels are the only option. The upside to them is that they can be easily cleaned and maintained. Their downside is that they can’t be used year-round in cold regions because they may crack if they freeze.

Above-ground cisterns are made from metal, fiberglass, or plastic. A popular and cost-effective above-ground option is The Original Rainwater Pillow by Rainwater Collection Solutions. This product is easy to add as part of your green home package because of its easy installation (no hole to dig) and reasonable cost.

The customizable product can hold from 1,000 to 200,000 gallons of water. Made of a reinforced polymer alloy, the unit is flexible but not elastic. “We can customize this product to the exact size,” explains company owner Jim Harrington. “It is horizontal, so it can be placed in the most wasted spaces in a home—under a deck or in a crawlspace.”

The storage system works with any external pump. While Harrington admits that underground systems have the benefit of ground heat to keep them from freezing, he says winterizing a RainPillow is simple: You drain the pump outside and either leave it where it is or fold the pillow and store it elsewhere. Then, you divert the water at the downspout until you can hook it back up to the unit again. Harrington also notes that if you place the catchment system in a conditioned crawlspace, you don’t have to worry about it freezing.

To give an idea of the cost, Harrington says that a basic 2,000-gallon unit costs $3,500, has only three fittings, and can be installed for about $400 using the installer kit.

Another above-ground system is the Rainwater HOG, which retails for about $300. This novel solution for rainwater storage is useful for properties where space is at a premium. The 50-gallon unit’s relatively small size allows it to fit in tight places, and the system is modular, so its capacity can be increased bit by bit and in multiple locations around a house. The narrow profile works well along side walls, down narrow passages, and underneath decks. A unit can sit flat, on its side, or upright.

If above-ground catchment isn’t suitable for your purposes, there are many below-ground rainwater catchment systems to chose from. The Cultec system is cost effective from a material standpoint and contractor friendly because the “nested” units can be transported in a standard pickup truck. (Other systems use large solid tanks made of concrete or plastic, which need to be transported with special equipment.)

“In many cases, rain water recovery systems are retrofitted and installed on existing properties, so moving heavy equipment may be difficult and potentially damaging to those residences,” says DiTullio. The system costs approximately $3,000.

Another underground option is Graf Rain Harvest Systems’ RainMaster 1700-IG Rainwater Collection System, which retails for about $3,300. The system includes a 1,700-gallon undergroundcistern with a childproof lid, a filter package that is suitable for roof areas up to 3,750 square feet, and a submersible automatic water pump with integrated on/off control and run-dry protection.

What differentiates this product is its durable tank manufacture. It is the largest tank of its kind to be manufactured by injection compression molding, and the wall thickness is equal in all areas of the tank, which creates such stability that the tank won’t collapse if it remains empty.

The Future of Water

By learning the mechanics of rainwater catchment and understanding basic differences between the options available, you can help your home buyers reduce their water bills and live a more sustainable life. But equally important is to be water-wise in all areas of the house and to plan ahead for water conservation methods.

“If you don’t build a rainwater system on the front end, it gets hard and expensive to put it in afterwards because the best way to capture rainwater is in an underground tank with a hookup to drip irrigation,” says Jerry Yudelson, author of Dry Run: Preventing the Next Urban Water Crisis. Yudelson also notes that builders should provide home buyers with water-conserving appliances and smaller lawns. “If you look at the EPA WaterSense program, the number one way to cut water use is by reducing the size of the lawn and using good xeriscaping. But lawns are a cultural issue, and builders simply build for the market and are not creating change.”

The building industry should educate home buyers on the value of water catchment—offering systems as a standard or upgrade feature and giving home buyers a sell sheet on the benefits of conserving water through rainwater catchment. “At a minimum, sustainable builders should design for potential future rainwater harvesting system installations to include provisions for gutters, downspouts, location of storage tanks, pumps, controls, and sanitation features,” advises Hammerstrom.

DiTullio believes that water conservation reform will come, whether builders or home buyers push for it. “The major change I see coming forth is based on the rising cost of clean water. It is a very reasonable assumption that rainwater harvesting will be seen as a better option than having that costly resource simply drain back into the ground untapped,” he says.

The uptick in rainwater catchment use will continue to grow in arid areas of the country and by early adopters, who see it as an easy way to live more sustainably.

“Rainwater harvesters are primarily conservation and efficiency advocates,” says Hammerstrom. “It makes no sense to spend precious funds to augment the supply of water if you haven’t extracted the greatest benefit from increased water efficiency and conservation first. If you were driving down the road and found that your parking brake was on, the first solution would not be to buy a bigger engine.”

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