Recycled Soil and Aggregate

1. It's not clear to me that you intend to reuse the material on your own site. A material has to be permanently installed in your project to qualify for MRc4 so, unless you intend to get the soil treated and reinstall it on your site then this won’t count. If that IS what you intend to do, then I would say you may have a good case for MRc4, as well as MRc5.

2. All you need to do to earn SSc3 is demonstrate that your site is contaminated, remediate as required, and redevelop the site. HOW you implement the remediation, e.g.: upcycle the contaminated soil, won't make any difference in earning the credit so long as the remediation is done in an approved manner.

With those downers out of the way, I will tell you that I have had success in an analogous situation in crediting the material towards MRc2 Construction Waste Management. I had a project where the soil contamination was high enough that it had to be removed from the site, but low enough that it could be used as alternate daily cover at a sanitary landfill. This gives the material a market value because it saves the landfill the expense of excavating or trucking in clean cover. By documenting this I was able to get my MRc2 percentage above 95% and earn 2 points for MRc2 + 1 Exemplary Performance point. I think you would be accomplishing a similar thing by upcycling the soil and therefore keep it out of the hazmat landfill.

One important caveat: I had to produce documentation from the AHJ affirming that the contaminated soil was acceptable for use as alternate daily cover. Whatever approach you may take to reprocessing or diverting this material I would ask the vendor to document that their process has regulatory approval. Otherwise, I could foresee a LEED reviewer not accepting it solely based on the vendor’s claims.

Hi Lyle - You present an interesting situation. Here are a couple of thoughts to add to Joseph’s response.

1. I don’t think you can just add Section 31 20 00. The only section heading in Division 31 that is allowed is 31 60 00 Foundations. I mean you could try this but I think it would be a long shot.

2. If the soil is not from your site, I don’t know how you could apply for SSc3, which deals with your site being a brownfield itself and redeveloping it.

3. I think the ID route is your best approach but these are tough to prove.

In a LEED charrette just yesterday, we discussed that there are some sustainable practices that the project should use even if they don’t count for LEED. Maybe this is one of those cases?

Pre-LEED v2009, the CSI divisions allowed for the MR credits were Divisions 2-10 under the previous version of MasterFormat (1995). It was a big improvement when the BD&C Reference Guide for LEED 2009 actually spelled out these sections and divisions are allowed based on MasterFormat 2004. A lot of site-related sections were removed from consideration when Division 2 was split out wide and far in MasterFormat and only the listed sections for Divisions 31(Section 31.60.00 Foundations) and 32 (Sections 32.10.00 Paving, 32.30.00 Site Improvements, and 32.90.00 Planting) were included in LEED's MR credits.

It would be great if a reviewer could answer your question on 31 20 00 but I am not aware of anyone who is monitoring this forum to answer questions.

We have an Owner with a campus. Our LEED Silver project is has it’s own Project Boundary and is not submitted as a campus. As we started our new project, the Owner demolished an adjacent 2 story warehouse structure comprised of concrete and CMU just outside of our Project Boundary. The demolished structure was also elevated approximately 4' above grade.

In anticipation of our LEED project, we had the Owner grind the concrete and block for reuse in the upcoming project. They also salvaged the 4' subgrade and stockpiled these materials which we have reused on the new project.
We want to maximize our credit for these items and are not sure how to do that. It seems that the cost to grind and the associated cost to haul in like materials would be applicable as recycled content.

We'd appreciate some guidance if anyone would be kind enough to assist.

Joel, I had a nearly identical situation on a past project where we crushed concrete and masonry demolition debris and used it as base material under building slabs and paved areas. We had the contractor determine what it would have cost to purchase similar material and have it trucked to the site, and assigned that value to the reprocessed materials.

This approach did not generate any comments from LEED during review and we got credit for the material. Also be sure to include the value in your Regional Materials calculations since the stuff is coming from right next door.

Joel - Joseph’s detailed answer covers your issues related the concrete and CMU that was ground into a new material - MRc4 and MRc5 (be sure you have the Reference Guide addenda for 7/9/10 related to recycled materials also being regional).

The only caution flag I would raise is to be sure that the materials actually fall under the CSI MasterFormat Divisions/Sections stipulated as covered by the MR credits (CSI MasterFormat™ 2004 Edition Divisions 03-10, 31 (Section 31.60.00 Foundations) and 32 (Sections 32.10.00 Paving, 32.30.00 Site Improvements, and 32.90.00 Planting). Foundations may sound all well and good but if you look at MF 2004 this is Special Foundations and Load-Bearing Elements like driven and bored piles, caissons, and other special foundations. Excavation and fill fall under 31 20 00 (Earth Moving), which is not covered. Possibly this subgrade would fall under 32 10 00, which is actually Bases, Ballasts, and Paving but you do not stipulate exactly how it is being used. Or it could fall under Division 3 Concrete. (Note that under LEED v2, we had more leeway to include site materials due to the entire MF 1995 Division 2 being included.)

Regarding the 4” subgrade that was “salvaged,” this material would fall under MRc3 and MRc5 because the material was not remanufactured into something new but is being reused as subgrade.