NEW YORK (Standard&Poor's CreditWire) Aug. 9, 1999--Standard&Poor's today assigned its single-'A' rating to Newark Unified School District, Calif.'s $13 million capital appreciation bonds series 1999 due Aug. 1, 2024. The bonds are scheduled to sell Aug. 12, 1999 In addition, Standard&Poor's affirmed its single-'A' underlying rating (SPUR) on the district's outstanding GO bonds. The rating reflects: -- Participation in the San Francisco Bay Area's strong and diverse economy; -- Above-average income and wealth; and -- A large and steadily growing property tax base. These strengths are somewhat offset by moderate yet growing debt levels and slow amortization. The district encompasses 13 square miles in southwestern Alameda County, serving the city of Newark, 35 miles