Sustainable Land Development Today - March 2009 - (Page 7)

Larry Stephens, P.E., president of Stephens Consulting Services, of Haslett, Michigan, underscored the point during a presentation at the Onsite Wastewater Conference in Corvallis, Oregon. According to figures he quoted from the Environmental Protection Agency, each day this country draws an estimated 38 billion gallons of water for domestic use. The average person in this country uses 50 to 55 gallons per day of potable water for domestic purposes which then becomes wastewater. Of that volume, each person flushes 13 to 15 gallons down toilets alone. In total, the country uses 402 billion gallons of water per day, which includes domestic, commercial, agricultural and industry uses. With 75 percent of the population being served by centralized water and sewer systems, it is estimated that 14 percent is lost due to leaks in that infrastructure, or 56 billion gallons per day. “New water is not manufactured every day —- we reuse what we have here on earth. We just don’t stop to think about how long and inefficient that cycle is,” Stephens said. The water is piped great distances to be treated for consumption or for commercial/industrial uses, which turn it into wastewater after one use. This wastewater is then piped great distances once again to be treated, and discharged into lakes and streams, a portion of which is extracted again by someone else who repeats the cycle. “We spend a lot of our resources moving water, most of which we use for nonpotable purposes,” he said. “On the other hand, if we capture wastewater near the source, treat it there, and then reuse it there, we save significantly on the costs of treating and piping that portion of the potable water we would use, and transporting away and treating the wastewater generated.” Applications There are multiple ways this concept can be implemented for new as well as existing projects, and it is scalable, de- pending on each application. Just a few of the non-potable purposes include flushing toilets, irrigation, cleaning and washing services, cooling systems and commercial/industrial processes. Similarly, there can be different ways that a decentralized system can “mine” wastewater from an existing municipal sewer line. For instance, a decentralized system could connect to a sewer line anywhere along its path to the centralized sewer plant, draw off wastewater, treat it and utilize the reuse water locally. The sludge taken from the wastewater can be put back into the sewer main to be sent to the central plant. Another would intercept some of the effluent, which has already been treated at the central plant; treat it again to a higher standard for reuse. Residual sludge from this additional processing would be routed to the sludge leaving the central plant. Such systems could be set up for sub divisions and other residential and mixed-use developments as well as for commercial/industrial sites. www.SLDTonline.com 7 http://www.SLDTonline.com

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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