Dimensions - November/December 2009 - 5

Taking the LEED Opportunities and Challenges in the Wastewater Sector In recent years, the rapid growth of green buildings not only is changing the built landscape but also has an impact on other industries, including the water and wastewater sector. Velmurugan Subramanian, PhD, PE, BCEE, LEED AP, a senior process engineer with Dewberry, addresses this complex issue in an excerpt from the September 2009 Water Environment & Technology Magazine. Green buildings are designed, constructed, and operated to boost environmental, economic, health, and productivity performance over that of conventional buildings. In the most current U.S. Green Building Council Leadership in Energy and Environmental Design (LEED®) rating system, water efficiency is addressed as one of seven major areas and is provided with a maximum of 10 credit points out of 100 points available. As a minimum, 20 percent water use reduction is a prerequisite for a project to be eligible for LEED certification. What different technologies for water and wastewater volume reduction are encouraged? Although the technologies and options for compliance are open to the project team, suggested alternatives for achieving credits in the water efficiency category are use of high-efficiency fixtures and dry fixtures (such as composting toilet systems and nonwater-using urinals), reuse of stormwater, reuse of graywater, use of recycled wastewater or use of water treated and conveyed by a public agency specifically for nonpotable uses, and infiltration or use of tertiarytreated wastewater on site. Onsite mechanical and natural wastewater treatment systems can include packaged biological nutrient removal systems, constructed wetlands, and high-efficiency filtration systems. What wastewater industry trends do you foresee as the green building market continues to expand? Development of new technologies and improvements in existing ones, as well as increased investment in existing or new treatment plants to meet the higher treatment standards for reuse applications. For instance, onsite wastewater treatment systems will receive more attention, paving the way for more decentralized wastewater treatment systems. This will not only save the cost of transporting wastewater to centralized treatment systems but also will encourage reuse of treated wastewater on site. Operation and maintenance and use of reliable technology to meet end-use standards on a consistent basis will be a main consideration when selecting onsite treatment. Any failure of onsite wastewater treatment due to use of improper or unproven technology or lack of operation and maintenance will be detrimental to gaining public support for treated-wastewater reuse. What opportunities and challenges do you anticipate for publicly owned treatment works (POTWs)? With a potential increased demand for treated wastewater for nonpotable purposes, POTWs may begin to treat wastewater to the highest standards for reuse applications, thereby generating additional revenue. More research and development efforts also may be required for the development of innovative and energy-efficient technologies to offset the increased cost of producing high quality treated wastewater for reuse. And finally, since the design standards and manuals of most regulatory agencies cover mostly conventional treatment systems, more resources and efforts will be required from regulatory agencies to update the standards that would support sustainable approaches to wastewater solutions. The intent is to reduce water consumption and encourage the reuse or recycling of wastewater to reduce wastewater generation.

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Dimensions - November/December 2009

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