This estimate for the potential number of FGD retrofits considers the resource and labor requirements of the simultaneous installation of SCRs, which is further discussed under the labor section (6.
No other information is available on the subject. 
mnli hypothesis: No other information is available on the subject.  premise: This estimate for the potential number of FGD retrofits considers the resource and labor requirements of the simultaneous installation of SCRs, which is further discussed under the labor section (6.