Accessible Web Applications (Score 1)

I create database web applications for a government organization. We have a public website, a general intranet, and departmental applications.

I can understand why our public site and general intranet should be accesible to all. However, I have a hard time understanding why a database application used by one or two (non-impaired) data entry people must conform to 508 standards.

Do the same section 508 accessibility standards apply equally to both public sites and limited use data entry applications?