And it's hard to say whether that's just the local market for engineers or if a large employer nearby is pulling minority engineers at a higher than average rat

And it's hard to say whether that's just the local market for engineers or if a large employer nearby is pulling minority engineers at a higher than average rate that skews the local market for the rest of the potential labor pool. In your example, I might question the lack of ANY other minorities in that company. In my local market, for example that 10% Black engineer number is way over-representing, but I'd expect ~30% minority for an average engineering organization.