SAN FRANCISCO (Standard&Poor's) Sept. 12, 2001--Standard&Poor's assigned its single-'A' rating to Alameda-Contra Costa Transit District, Calif.'s $23.33 million certificates of participation (COPs) series 2001. The certificates are scheduled to sell Sept. 25, 2001. The outlook is stable. Lease payments from the district act as security for the COPs. The district may use any source of legally available funds, including sales and property taxes and farebox revenues, to meet its lease and rental payment obligations. The rating reflects: -- The strength and diversity of the available revenue stream; -- Good essentiality of the leased asset, an office building; and -- The Alameda-Contra Costa Transit Authority's participation in the San Francisco Bay Area's employment base. These strengths are