LEED has been focusing on design for less dependence on external supply of water for Green buildings. This is done by various methods such as rain water harvesting, low water consuming showers/taps, waste water treatment. Water related pilot credit points 10, 17, 18 are proposed to address the water resource reuse and water consumption for specific equipment (cooling tower/dish washers/laundry equipment etc.)These pilot credit points are under proposal stage and shall be implemented after considering feedback on the same.
POSSIBLE FUTURE CREDITS UNDER REVIEW, What do you think?
Pilot Credit 10: Sustainable Wastewater management: This credit focuses on minimising water usage for urinals/toilets and reuse of resources from waste water. There are three ways of achieving this credit point. First option is by minimising use of water for sewage conveyance, for example use of dual flush system for toilets, but this option should be thoroughly studied for negative environment impact such as air pollution and energy use. Second option is by complying with NSF 350 or local standards and the third option is by extracting resources such as organic carbon and nitrogen. There are some issues which are still under discussions Such as, is this credit applicable if the sewage water is treated outside LEED boundary? Is this credit eligible for achievement of exemplary performance?
“When the well is dry, we know the worth of water. “Benjamin Franklin 1746.
Pilot Credit 17: Cooling tower water use: Correct selection and regular maintenance of cooling towers in any central air conditioning and process cooling system is important to keep the whole system sustainable. As cooling water system is an open water circuit, the cooling water is exposed to atmospheric air, which adds impurities in the system. These impurities can cause corrosion and erosion of various parts of cooling water system such as piping, valves, pumps etc. Cooling tower with low drift loss helps to reduce make up water requirement. This credit is awarded for use of cooling towers with acceptable water quality (TDS, Conductivity), low drift loss, precise measurement of water quality and flow rates etc.
Pilot Credit 18: Appliance and process water use reduction: This credit requires selection of process water equipment approved by CEE (Consortium of energy efficiency) or appropriate ENREGY SATR rating. There are no limitations on number of equipment used for any project. Application for this credit requires equipment model number, catalogue, submittals, single line diagram showing supply water flow rate and effluent drainage system etc. Some of the equipment may add to above list after receiving feedback from experts.