See all forum discussions about NC-2009 SSc6.2
 Subscribe to new posts about NC-2009 SSc6.2 Post a new question aboutNC-2009 SSc6.2
See LEEDuser’s guidance on NC-2009 SSc6.2»
FAQs about SSc6.2 :

What performance threshold do I need to achieve for an Exemplary Performance point?

The calculations for this credit are always a headache! While our projects are usually awarded the credit, the equations in the LEED Reference Guide are helpful mostly for sizing a reservoir or cistern, but don't help you get to the final results. Does US

Why do the requirements focus on 1-year and 2-year, 24-hour storms?

Why include the 1-year storm in the credit requirements? Won't management practices for the 2-year storm be effective?

How can green roofs count as a stormwater control measure?

How can I achieve compliance if my project's stormwater control measures are outside the LEED project boundary?

I have 100-year data—how do I convert to 2-year?

Is it an acceptable strategy to capture the rainwater into tanks and discharge it into the public sewers after the rainstorm reducing the peak discharge?

Are there special considerations for international projects?

View answers »

Forum discussion

NC-2009 SSc6.2:Stormwater Design—Quality Control

Alternative Compliance-High Infiltration

Site is located in western Wasington state. We are using the western Washignton Hyraulic model #3 to size the underground detention. The infiltration rate for the site is 50"/hour. Using the LEED volume calculation, which requires 90% of the average annual rainfall to be captured, requiring the underground detention to double in size. Becasue of the high infiltarion rate is it possible to use an alternative compliance method to show the LEED volume calculation is onerous as the water will infiltrate, and the size isn't necessary.

0
Post a reply

You rely on LEEDuser. Can we rely on you?

LEEDuser is supported by our premium members, not by advertisers.

Go premium for $15.95  »

Profile picture for user Mike Dee
Michael DeVuono
Regional Stormwater Leader
Arcadis North America
LEEDuser Expert
144 thumbs up

Tue, 05/15/2012 - 14:44

You don't need to "store" any volume of water with this credit, you need to treat it. Is 90% of your site not routed through the basin? If not, i would simply model your ground cover as a "pseudo-infiltration practice." Does 90% of your site hit areas with 50"/hr infiltration rate? I would caution against using such a high number, unless that is something typically used in Washington. (I'm not familiar at all with the Left Coast). I would get laughed at around here if I tried to submit any kind of calc using 50"/hr.

Fri, 05/18/2012 - 10:50

I might be wrong, but as I see, it seems that the intention of this credit is to minimize polluted storm runoff getting into stormwater lines. So if we minimize this runoff thats one strategy and the runoff which is still going into stormwater lines, it has to be treated to remove 80% of TSS and its second strategy. We can store water for other purposes but polluted stormwater runoff should be prevented from entering municipal storm water lines, thats what I think.

Add new comment

To post a comment, you need to register for a LEEDuser Basic membership (free) or login to your existing profile.