"Brookville"@en . "County seat"@en . . "4004"^^ . . "Brookville is a borough in Jefferson county. It is the county seat for Jefferson county. The 2008 estimated population is 4,004."@en . "Borough"@en . . "Brookville is a borough in Jefferson county. It is the county seat for Jefferson county. The 2008 estimated population is 4,004."@en . . . .