Hi, in our project we have a 60% of the site vegetated, planted with meadow, we have a small impervious surface near the building, and the building itself. We understand that the vegetated area treats 100% of the TSS removal, then the water from the roof and from the impervious area is guided to a rainwater cistern and this water reused (to irrigation, lavatory faucets and wash machines), this should be also counted as 100% of TSS removal? Then another question is that although we have a 135m3 rainwater cistern, in a stormwater event is probable that the cistern is full and than the water would have to be guided to a near water body without passing trough the cistern. Since we cannot achieve information about the filters that we also have, how could we justify the credit? Can we propose a sistem where in the event of a stormwater, in advance, we empty the rainwater cistern so we can capture al the stormwater? Thanks in advance

Post a reply

Michael DeVuono

Regional Stormwater Leader

Arcadis North America

LEEDuser Expert

144 thumbs up

Wed, 03/06/2013 - 16:44

I question your 100% TSS removal for routing through a planted area. Where are you getting that number from? 60-65% seems more the norm, but perhaps you have more information to back up your assumption. As for your cistern, any cistern design should take into account back to back storms, and you total water budget. You need to actually be using the water you are storing. Proper sizing will help to reduce the risk that the cistern is full in the event of a back to back storm (less than 3% chance of happening with the 2-year event). Can you not bypass the cistern and route through the meadow you have?

Albert Sagrera

Architect

Societat Organica

LEEDuser Basic Member

11 thumbs up

Wed, 03/06/2013 - 17:23

Thanks for the quick answer!! Well the 100% TSS removal for the vegetated area, i assumed that this kind of pavement would be what LEED considers a soil with good infiltatation rate "As long as your soil type has a good infiltration rate, letting stormwater seep into the ground will treat 100% of the pollutants associated with the stormwater runoff." But then maybe in this planted area, as a semi compacted soil, might be reasonable reduce the efectivity, thanks for the data!! The cistern capacity was calculated tacking into account the climate profile of Barcelona, it occurs that we have a highly variable rainfall regime, so we dimension de cistern so it can provide all the water we need in summer (when we have a high demand and almost no rain). The stormwater events generaly occur in october...

Add new comment

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

You are currently logged in under an enterprise account

FAQs about SSc6.2 :

some doubts

You rely on LEEDuser. Can we rely on you?

Add new comment