Rating System

LEED BD+C: New Construction, LEED BD+C: New Construction, LEED BD+C: Schools, LEED BD+C: Schools, LEED BD+C: Core and Shell

Rating System Version

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

Inquiry

The infill project we are currently working on requires rainfall onsite to be deposited in existing drainage and combined sewer networks at the same rates as the predevelopment conditions. The City of Sacramento has mandated that we refrain from drainage shed-swapping. This requirement requires 0.60 acres of the 2.51 acre site to be drained to the combined sewer. In order to meet the requirements for SSc6.2, we\'ve currently designed 2 stormfilter structures to treat 91% of the average annual rainfall to 90% TSS. One treated outfall connects to a dedicated drainage system while the other connects to a combined sewer. As an alternative to using 2 stormfilter structures, we propose to omit one of the filters and to use one stormfilter in order to treat only the portion of the site that flows to the dedicated drainage system. Our reasoning is that constructing, transporting, and installing a treatment structure that discharges to a combined sewer would not make economic or environmental sense. The treated outflow from the site would be much cleaner than the contents of the combined sewer. While our proposed solution does not meet the letter of the SSc6.2 requirements, we believe that, at the bottom line, it\'s a more sustainable approach, and that it meets the intent of SS6.2. Using our proposed approach, would our project still quality for the SSc6.2 credit?