Standard&Poor's Ratings Services affirmed its 'BBB+' Standard&Poor's underlying rating (SPUR), with a stable outlook, on Roseland School District, Calif.'s certificates of participation. The SPUR reflects the district's: Moderate sized property tax base with assessed value of $733 million for fiscal 2007; Income levels that are below average compared to Santa Rosa, Calif. and Sonoma County levels; and Potential capacity pressures due to student enrollment growth -- The overall debt burden, however, is currently manageable. A satisfactory $2.3 million unreserved general fund balance, or 16.7% of expenditures, for fiscal 2006 somewhat offsets these rating weaknesses. Lease-rental payments, which the district covenants to budget and appropriate, secure the certificates. The three-square-mile K-6 Roseland School District, with a population