Sustainable Land Development Today - March 2009 - (Page 6)

SLDT FINANCE WASTEWATER Sewer Mining: A Hybrid Solution Decentralized wastewater systems tap into centralized systems to create on-site reuse water. By Frank Hill he concept has been around for more than 30 years, but is gathering momentum as this country, and the world, faces an escalating water crisis. Using smaller, decentralized systems to draw off waste water from established, centralized-sewer systems is proving to offer wide-ranging benefits. It is called different names by different sources, from sewer scalping to water mining to wastewater mining to sewer mining. For this article, the last option was chosen. Sewer mining relieves pressure from traditional, centralized systems by intercepting a portion of their volume, which is diverted to be treated and put to additional use. By extension, that relieves some of the strain on municipal water supplies because each gallon of water sees more than one use. That is especially beneficial to drought-stricken areas. There is also potential for the reuse of sludge materials as well as the nutrients left in the treated wastewater, truly mining the wastewater for its contents. There is even some discussion of a process that would capture the heat-generating potential of wastewater to produce electricity. T Here, we will primarily look at sewer mining as it can be applied to relieve demands on fresh-water supplies, save capacity in existing sewer pipes and at existing wastewater treatment plants, and to the broader issue of conserving a critical resource. Background and Scope Greenville, South Carolina-based Aqueonics is credited by many for pioneering the concept of sewer mining in 1982 for a project in Upland Hills, California. The company worked with the local utility to serve a new development of more than 800 units. The company tapped into the utility sewer system, and treated the wastewater for reuse. This meant a benefit for taxpayers because their local, public utilities did not have to expand to accommodate the new development, and they got more bang for the buck on each gallon of water. Over time, as water shortages and drought have affected many areas of the world, the idea has gained more and more attention. In the United States, it has attracted notice in recent years as areas with some of the highest population growth have also experienced drought conditions and water shortages. The push to get more than one use out of every drop of water has become more serious. Shane Keaney, president of Bord na Móna Environmental Products U.S. Inc., a manufacturer of decentralized and residential wastewater treatment and water reuse technologies, says that according to the Palmer Hydrological Drought Index, 38 percent of the United States experienced moderate to severe levels of drought by the end of 2007. By 2013 water shortages are anticipated in 36 states. He supports a new approach to the treatment, storage and reuse of water on a residential, industrial, and municipal level. “The aging United States water-treatment infrastructure now requires significant investment just as water shortages are increasing in magnitude throughout the south and west of the country,” Keaney said. “Many of our current municipal wastewater treatment systems are large centralized works that often waste the water resource rather than reuse it, and consume too much energy to move wastewater from the source to the treatment plant.” 6 March 2009 Sustainable Land Development Today

Table of Contents Feed for the Digital Edition of Sustainable Land Development Today - March 2009

Sustainable Land Development Today - March 2009 Contents Our Voice: Energy Savings Accounts Mining the Sewers for On-site Reuse Modern Flood Disasters The Financial Challenge of Leed® Technology: Opportunities Exist to Buy in Now SLDI In Focus: A Look Inside Calendar of Events Energy: Solar Power on Rails Industry News Products & Services The Bottom Line: Green Lending – Class G Advertiser Index Editorial Board SLDT Resources Last Word: Not All Gloom & Doom

Sustainable Land Development Today - March 2009

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