Rating System

LEED BD+C: New Construction, LEED O+M: Existing Buildings, LEED BD+C: Core and Shell, LEED BD+C: Schools

Rating System Version

v3 - LEED 2009, v3 - LEED 2008, v2 - Schools 2007, v2 - LEED 2.2, v2 - LEED 2.0

Inquiry

This inquiry relates to the stormwater management infrastructure on a remote campus of a local University. The project has been developed in phases. In Phase I, a 2.0 acre stormwater basin was constructed. This basin exceeds the LEED quantity and quality requirements for 4.0 acres of existing impervious area that now drains to it. The existing impervious area is not part of our LEED applicant project and was previously untreated. This stormwater basin is considered part of our LEED project site and will also treat the runoff from our LEED applicant project. We are now in Phase II, and are adding 8.29 acres of impervious surface to the LEED project site. The stormwater basin constructed during Phase I is being upgraded as part of Phase II, by adding sediment collecting forebays, to increase TSS removal from both existing and new impervious areas draining to this basin. Approximately 6.0 acres (70%) of this new impervious surface will drain into the upgraded 2.0 acre stormwater basin and will be treated to LEED quality requirements. All of the remaining 2.29 acres of new impervious surface the LEED project is adding, in addition to 1.7 acres of existing untreated impervious area, will drain into a rain garden designed to remove at least 80% of the TSS and 40% of the TP in the water. The rain garden will drain into an existing County owned regional stormwater basin, not located on the LEED project site. Because we are treating 5.7 acres of existing impervious surface that is not part of our project plus 6 acres of our LEED project\'s impervious surface, we are hoping the USGBC will allow us to claim credit equivalence for both SSc6.1 and SSc6.2, despite the fact that 2.29 acres of our LEED project\'s impervious surface will ultimately drain into an off-site regional basin. Please clarify for our team whether we are likely to qualify for credit equivalence based on the scenario described above.