Parkland Memorial Hospital is expected to sell the last installment of bonds — $42 million — this fall to finance its new $1.27 billion public hospital that will open in 2015. The hospital's board of managers gave preliminary approval to sell the bonds as government obligation, repayable by Dallas County taxpayers, rather than revenue bonds, which would rely on hospital income for repayment. The bond sale must be approved by the Dallas County Commissioners Court, which oversees Parkland's budget and annual tax rate. The new bonds are expected to add less than a half cent to the hospital district's 27.1 cent tax rate per $100 tax value.