What is the wheel arrangement for the train in Riverdale, Georgia?
CREATE TABLE "table1_1057316_1" (
  "serial_number" text,
  "wheel_arrangement_whyte_notation" text,
  "build_date" text,
  "operational_owner_s" text,
  "disposition" text
);
SELECT "wheel_arrangement_whyte_notation" FROM "table1_1057316_1" WHERE "disposition"='Riverdale, Georgia';