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Anne Vazquez

Water: Put It Aside For A Non-Rainy Day

As demand for this natural resource continues to increase, facilities might consider rainwater harvesting to ensure supply.

By Anne Vazquez

In its 2005 “Report Card For America’s Infrastructure,” the American Society of Civil Engineers (ASCE) gave an overall grade of “D” to the condition of 14 categories, which included bridges, drinking water, rail, and wastewater. It stated that $1.6 trillion would be needed over a five year period to bring infrastructure in all of the categories up to good condition.

Two years later, the tenuous state of public infrastructure in the United States was brought to the forefront this past summer when a steam pipe burst in New York City, disrupting many surrounding businesses. Then, in August, the tragic collapse of a bridge in Minneapolis resulted in the deaths of 13 people. As officials at all levels address these issues in their respective locations, facility managers concerned with the safety and security of their buildings and grounds may want to look into ways to become more self-sufficient.

Water: Put It Aside For A Non-Rainy Day (Image courtesy of Heather Kinkade-Levario.)

Water is one area that should garner attention. The ASCE 2005 Report Card gave both the drinking water and wastewater categories a “D-” for the condition of infrastructure systems throughout the country. One way facility managers may be able to reduce pressure on this infrastructure is to install a rainwater harvesting system. Just as facilities professionals have the option of on-site energy generation (e.g. solar power), collecting rainwater on its roof enables a facility to provide itself with at least a portion of its water supply.

When facility managers reduce the amount of water used from municipal sources, they help to lessen the need for new infrastructure. Additionally, they save money with decreased water bills. Though water is relatively inexpensive in many areas, this may change in the near future, due to infrastructure improvements and a tightening supply. (A recent federal government survey showed at least 36 states are anticipating local, regional, or statewide water shortages by 2013.)

Another benefit of rainwater harvesting is the mitigation of stormwater runoff from the facility. Rain that would otherwise drain off roofs down to the ground is directed through the harvesting system to a storage tank. Heather Kinkade-Levario, Arizona director of planning for Denver, CO-based ARCADIS, points out in her recently published book, Design For Water: “The aim of rainwater harvesting is to concentrate runoff and collect it in a basin or cistern to be stored for future use.”

The complexity and cost of a system generally depends on the intended use for the collected water. For instance, if a facility wants to harvest rainwater for drinking water, relatively complex and expensive equipment will be required.

However, there are simpler systems capable of cleaning rainwater so it is suitable for landscape watering, toilet flushing, and laundry cleaning. Approximately 40% of water used in commercial and institutional buildings is used for those three purposes, so even a simple system can ease the pressure on natural resources and infrastructure.

Typical systems consist of five or six primary components (see illustration), depending on whether or not potable water is a goal. These components are: catchment; conveyance; roof washer (filtration); storage; distribution; and purification (for potable water). While there are multiple factors, the amount of water that can be collected depends heavily on the amount of rainfall and area and type of roof surface.

New construction projects are usually viewed as the best candidates for rainwater harvesting, since the system can be incorporated during the design stage. However, Kinkade-Levario, who has served as the 2005-2007 president of the American Rainwater Catchment Systems Association, notes there is opportunity for those in existing facilities.

“For an existing building, the biggest issue is to have somewhere to store the water,” she explains. “With rooftop rainwater collection, it’s relatively easy to put several storage tanks next to the building and direct it from the roof into the tanks. All drainpipes and downspouts need to be connected to transport the water to the tank. If the building has internal drains, it will be more difficult, because water is coming out at the base of the building.”

In terms of maintenance, most facilities teams are able to care for rainwater harvesting systems without calling in a service provider. “The systems are simple enough that in-house staff members can be trained to maintain them,” says Kinkade-Levario. “But, they do need to maintain them. This includes checking for clogs throughout the system and ensuring the water is being treated properly for the intended purposes.”

By using water efficiently, facility managers can help to preserve water supply, save money, and protect the environment. Harvesting the rain can be one part of the solution to this myriad of challenges.

Information for this article was based, in part, on information from Kinkade-Levario. For more information, visit the American Rainwater Catchment Systems Association at www.arcsa-usa.org.

Do you have a rainwater harvesting system at your facility? If not, would you consider installing one? Share your thoughts by sending an e-mail to avazquez@groupc.com.

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