Cement manufacture causes environmental impacts at all stages of the process.
The fact that Granulated Ground Blast-furnace Slag (GGBFS) isn’t quarried and baked before it comes to Vallejo is beside the point.
The salient question is whether shipping slag from Asia on ships using diesel engines, grinding and mixing it here, then shipping the products using nearly 600 truck trips a day is appropriate for a densely populated residential neighborhood, passing by our schools.
To focus on whether this final product is actually green is just a distraction.
We agree that GGBFS cement is better than Portland cement. But better doesn’t mean it’s good.