Mercury has been (will be) a problem for Y-12 since the 50s and 60s where they spilled over 70,000 pounds of mercury from the lithium separation process. I experienced this on a number of demolition/remediation projects out there. Storm drains near any project that disturbed soil is heavily protected to avoid mercury release offsite. A building I worked in had airborne mercury along with asbestos, beryllium, and the obligatory radioactive airborne.
DOE to UCOR: Finish work on the Mercury Treatment Facility at Y-12
https://local.newsbreak.com/oak-ridge-tn/3233902097176-doe-to-ucor-finish-work-on-the-mercury-treatment-facility-at-y-12
I wonder if DOE is unhappy with APTIM-NW, letting their contract expire?