Originally housing inmates from the 14 northwestern Pennsylvania counties. In 1986, the facility also accepted inmates from the southwestern 9-county region that were utilizing SCI-Greensburg. Presently, inmates from all over the commonwealth are housed at SCI Mercer.
There are 30 buildings on SRCF Mercer's Campus (23 inside the 37.5 acre fenced perimeter). The campus is air-conditioned (electric system) Nine diesel backup generators serve as emergency power. The institution operaes its own sewage treatment plant, having a 104,000 gallon daily capacity.