Suresh asks: Hi, I have two questions regarding the exclusion of waste generated during a manufacturer's own process.

a) Glass cullet is typically used during the manufacture of glass, and is typically made from recycled bits of glass that is thrown back into the manufacturing process to reduce the process temperature. This recycled glass (which can be up to 20%) is not allowed for calculation of pre-consumer content. My question is this: if the recycled glass came from another factory - say a glass bottle recycling factory, is the glass cullet now eligible for inclusion?

b) Rockwool manufacture typically involves melting big lumps of basalt and mixing it with slag from steel operations. In the past, rockwool manufacturers were not able to recycle their own product back into the manufacturing process, simply because the manufacturing only accepted "big lumps" of basalt. A rockwool manufacturer that we use has recently invested a large sum of money to allow him to accumulate the waste from his manufacturing process and compress the strands into bit lumps for re-entry into his manufacturing process.

It seems strange that this huge expenditure to encourage recycling doesn’t entitle the manufacturer to pre-consumer points?

Answer: Suresh, first I feel the need to preface this answer with a disclaimer. I don’t profess to be an expert on the LEED rating system (I haven’t had a LEED project to date in which the Green Building Certification Institute, GBCI, hasn’t requested any clarifications on any of my submittal documentation). Nor am I in any way affiliated with the US Green Building Council’s (USGBC’s) development or interpretation of credits.

That being said, I’ll not go ahead with my thoughts in regard to your questions. Hopefully it will be helpful, but ultimately what USGBC and GBCI dictate goes as far as what is and isn’t acceptable for a credit. So if you’d like to get an answer that would be applicable to your credit, you can submit a Credit Interpretation Request (CIR).

Unfortunately "Effective June 26, 2009, credit interpretation requests (CIRs) submitted by any registered project will no longer be vetted by USGBC or its LEED Technical Advisory Groups. As a result, CIR rulings (the result of a Credit Interpretation Request) will now be applicable only to the project that submitted them. For LEED version 2 projects, rulings on CIRs submitted prior to June 26, 2009, will be honored until they are retired by USGBC or incorporated into general USGBC-issued project guidance, such as through errata or addenda."

This means that when you get this question ‘officially’ answered, the answer will be only known to you (unless you decide to share it) and even if the answer was inclusive of the items you mention, that would not create a precedent towards other projects. Ultimately, from past experience I can tell you honestly, if the reference guide specifically calls our that something is not allowed, under no circumstances will there be any exception.

To your questions… the Green Buildings Design & Construction Reference Guide describes pre-consumer material as ‘material diverted from the waste stream during the manufacturing process’. It goes on to say that ‘re-utilization of materials (i.e., rework, regrind or scrap generated in a process and capable of being reclaimed within the same process that generated it) is excluded.’

So, essentially, reclaiming materials from the same process is good practice but cannot contribute toward recycled content because putting waste back into the same manufacturing process from which it came isn’t recycling. The waste was not diverted from the waste stream. Glass culls are specifically called out as an example of materials reuse that is not eligible for this credit. Attempting to get around this requirement on a technicality (the fact that the culls would maybe come from another factory) will almost certainly result in the culls being excluded no matter what, IMHO.

Similarly for the rockwool process you cite, I imagine this content would be excluded again due to the fact that the material is being reclaimed from the same process in which it was generated and therefore doesn’t meet the Reference Guide’s definition of recycling.

Again, though, this is just my opinion. For an official ruling, a CIR would be in order.

Good luck!
Sarah Gudeman, LEED AP

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