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Fabric products help conserve water

January 1st, 2011 / By: / Feature, Geosynthetics, Sustainability

As supplies drop and demand rises, governments, companies and individuals look for cost-effective ways to save a limited resource.

Picture 26 Olympic-size pools filled with water. That’s how much of the precious resource was prevented from evaporating in a year’s time from five storage basins in Australia—just by covering them with fabric that is 97 percent lightproof.

Although the primary goal of putting the water under cover was to control algae, the shading reduced evaporation by 90 percent, reported Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO).

Gale Pacific Ltd., which provided its Synthesis® Commercial 95™ advanced polymer shade fabric for the trial project, also makes dam liners, tank liners, water bladders and irrigation flumes. “Water is becoming a commodity of ever-increasing value to farmers, industry and the general population at large. It has also gained serious political attention,” says Anthony Scott, general manager of international sales and marketing for the Melbourne, Australia-based company. “Specialty fabrics play an important role in terms of storage, transportation and water quality. They provide flexibility in terms of quick, efficient and cost-effective deployment that can oftentimes be reliably relocated, as opposed to solid structures such as concrete pipes.”

While dam liners are durable and have a long life span, Scott says, “they typically require on-site fabrication, which in remote areas can be extremely expensive in terms of time and resources. A good alternative would be wide-width, lightweight materials that can be fabricated into large panels off-site and transported to remote areas for quicker on-site deployment.”

Going with the flow

“Water conservation and storage is probably our third-largest market behind waste containment and mining,” says Boyd Ramsey, chief engineer for GSE Lining Technology LLC of Houston, Texas. “We expect it to grow at a faster rate than waste containment and mining. Water is just becoming more valuable. It’s limited. The Rio Grande doesn’t even reach the Gulf of Mexico anymore.”

Canal lining is GSE’s most active water-conservation application. Ramsey points to a U.S. Department of the Interior study encompassing 34 test sections in four states that compared different types of canal liners. Concrete alone reduced seepage by 70 percent, exposed geomembranes reduced seepage by 90 percent and concrete-covered geomembranes reduced seepage by 95 percent. Whichever alternative is used, the report concluded, every $1 spent on maintenance returns $10 in conserved water.

According to Ramsey, three-quarters of leakage problems in geomembrane canal liners result from damage during installation (typically from animal and equipment traffic), so GSE relies on specially trained construction personnel.

“You need a good skill set and current equipment,” Ramsey says, noting that the International Association of Geosynthetic Installers offers an accreditation program for installers. “The other thing we recommend,” he adds, “is construction quality assurance. The Geosynthetic Institute runs a program for certified quality control assurance inspectors.”

Water conservation products aren’t just for government and industrial users. Gavin Hodgins, operations manager for Flexitank (Australia) Pty Ltd. of Victoria, recalls when water reserves dropped to 25 percent in Melbourne about three years ago.

“Everyone was forced to save water and start to look at different ways to capture whatever water they could,” he says. While rainwater tanks were already popular in rural areas, metropolitan areas began looking at their options, including Flexitank’s fabric-based RainPac™ bladders that could store water under a house foundation or decking.

“Although rainwater in metropolitan areas is generally not used as a drinking water source, the water collected in RainPac bladder tanks can be used to fill pools, ponds, and feed vegetable gardens and so on,” Hodgins says.

Made with reinforced PVC from a European supplier, the bladders come in 12 standard sizes, ranging from 1,000 to 8,600 liters (260 to 2,236 gallons). Flexitank’s largest custom-sized RainPac—installed under a shopping center development—holds 65,000 liters (16,900 gallons). However, Flexitank can make a pillow tank with even greater capacity: 250,000 liters (65,000 gallons). The company was commissioned by the College of the Marshall Islands to design and manufacture 19 tanks with customized fittings for 8-inch pipes to collect every drop of rain that falls. Most of Flexitank’s sales are in Australia, but orders have come from New Zealand, the United States and Germany; the company has appointed agents in New Zealand and will do the same in Europe and the United States within the year.

The land down under

While building architects are clamoring for the U.S. Green Building Council’s LEED designation, the Sustainable Sites Initiative™ hopes to transform land development and management practices with a national rating system for landscaping

Among the designated pilot projects is Sunnylands, the estate of the late Walter and Leonore Annenberg in Rancho Mirage, Calif. Opening in November as a retreat for world leaders, and educational center and gardens for the general public, the 200-acre desert property features its own solar farm, geothermal system for heating and cooling, and a desert landscape that will use no more than 20 percent of the permissible water under water district regulations. In addition to using drought-tolerant plants, the landscape architects recommended an underground irrigation system called KISSS™ (an adapted acronym for capillary irrigation subsurface systems) for the 10 acres of gardens.

“The Annenberg Foundation Trust at Sunnylands was very interested in saving water,” says landscape architect James Burnett of Solana Beach, Calif. “It is the most important thing we hear right now from all of our clients. It doesn’t matter what region—the United States, China, India or Mexico. Everything we design has to be scrutinized pretty carefully to ensure that we are using water responsibly. It is one of the first points of discussion in any of our kickoff meetings.”

Manufactured in Australia, KISSS was inspired by geofibers installed along rail beds to reduce weeds that could catch fire from sparks coming off railcars, explains Dave Hunter, president and CEO of Irrigation Water Technologies America Inc., Longmont, Colo. Those geofibers also wick water away from the tracks.

KISSS, whose primary function is water conservation, comprises five parts: a drip tube, geofiber draping the drip tube, emitters embedded in the tube, a polypropylene tape “antipercolation” layer below the tube that forces water horizontally through the geofiber and into the soil, and tape above the tube that deflects water downward. Since the water stays subterranean, it doesn’t evaporate and run off.

“There are three KISSS products, although there are some variations: Below Flow Wrap, which is particularly good for plantings, gardens and landscapes with irregular slopes; Below Flow Flat, which is particularly good for turf and flat areas that require water evenly distributed; and Ebb and Flow Mat, which is made for nurseries where plants get water through holes in the bottoms of pots,” Hunter says.

Four years ago, IWTA secured distribution rights from Irrigation & Water Technologies Pty Ltd. of Rouse Hill, NSW, Australia, and in the first quarter of this year plans to begin manufacturing in Longmont. “We are projecting an increase [in business] over the course of the next three to five years,” Hunter says. Burying the system requires a product-specific plow, which can be purchased, rented or leased. The company certifies installation contractors, “but it’s not rocket science,” Hunter says.

“One of the things officials and governments could learn is that Australia is on the forefront of water conservation,” he continues. “What Australia has done is valid and very important to consider.” In addition to spurring innovation in water-conserving products, the commonwealth offers incentives to encourage their use.

“We are seeing some [U.S.-based] government officials jumping on the bandwagon, because water is the next big crisis this country has to face after energy,” Hunter says.

A July 2010 report prepared by Tetra Tech, a research and consulting firm in Pasadena, Calif., for the Natural Resources Defense Council concluded that more than a third of all counties in the continental United States will face higher risks of water shortages by 2050 as the result of global warming. In arid and agricultural regions, the consulting and engineering firm noted, water withdrawal already exceeds 100 percent of precipitation.

Hodgins agrees with Hunter that regions around the world can take a lesson from Australia. “The fact remains that the world’s water storages continue to drop. Allowing everyone to simply use as much water as they want simply is unsustainable,” he says. “Also, the price of water continues to increase. As the shift focuses away from drought and to the cost of water, rainwater tanks, dams, ponds, etc., provide cost-effective solutions and will end up costing far less than water from main supplies. Many forecasters say that eventually water will be a more expensive commodity than oil.”

Janice Kleinschmidt is a freelance writer based in Palm Springs, Calif.

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