We are currently working on a project sited on a university campus. This university has a campus-wide wastewater (sanitation sewer, not storm water) collection and reclamation system in place. Our project is connected to this system. Storm water is collected from the roof of the project building and stored in a cistern. This collected storm water will be used solely for flushing toilets and urinals. The use of these two strategies seems to apply to every credit in the "Water Efficiency" section. In WE 1.1 and 1.2, the intent is to "Limit or eliminate the use of potable water for landscape irrigation". This intent is met by the campus-wide system above. Since a campus-wide system is already in place, it would be of little or no benefit to create a separate site system and we feel we should not be penalized for this. Project money has been utilized to connect the project to the university system. Will this system allow us to earn WE credits 1.1 and 1.2? We are currently incorporating a rainwater collection cistern into the project for flushing toilets and urinals (at least 50% of building water needs). Would this strategy alone earn us WE credits 3.1 and 3.2? The intent is to "Maximize water efficiency within buildings to reduce the burden on municipal water supply and wastewater systems." The rainwater cistern eliminates the need for municipal water. It would appear that this also meets the intent of WE credit 2; "Reduce generation of wastewater and potable water demand
Captured rainwater or recycled site water can contribute to achieving all of the water credits. To achieve credit for reduction of landscape water use, the landscaping/irrigation system must be designed to use water efficiently, or you must demonstrate that the rainwater collection system supplies enough water to the irrigation system to meet the calculated irrigation water demand for the month of July. See the LEED Reference Guide for calculation methodology. If your campus-wide wastewater system provides non-potable reclaimed water to the building\'s irrigation system at the levels required by LEED, you can earn the points for WE credits 1.1 and 1.2. Rainwater harvest can be used to offset potable water used for sewage conveyance and thereby achieve credit WE credit 2. Graywater supplied from the cistern can be applied on its own, or in combination with low-flow fixtures, to attain the 50% potable water reduction required for this credit. The calculation must be applied to fixtures which discharge into the sewer; landscape water use/savings does not count toward credit WE 2. Use the LEED calculator for assistance in performing these calculations. To achieve credit WE credit 3.1, the use of the roof cistern system must provide 20% of the total aggregate (in-building - excluding irrigation) water usage. Water conserving fixtures that use less water than EPACT requirements can be used in combination with rainwater harvesting to achieve this credit. Use the LEED calculator for assistance in performing these calculations. WE credit 3.2 - Use of the roof cistern system must provide 30% of the total aggregate (in-building, excluding irrigation) water usage. Water conserving fixtures that use less water than EPACT requirements can be used in combination with rainwater harvesting to achieve this credit. This could be important if the rainwater system doesn\'t meet the water use reduction requirements alone. Use the LEED calculator for assistance in performing these calculations. Note, if WE 3.2 is attained, then credit is also given for WE 3.1. Applicable internationally.