SELECT "Fastest lap" FROM table_31520 WHERE "Location" = 'Bowmanville, Ontario'
Who had the fastest lap in bowmanville, ontario?
CREATE TABLE table_31520 (
    "Rnd" real,
    "Circuit" text,
    "Location" text,
    "Date" text,
    "Pole position" text,
    "Fastest lap" text,
    "Winning driver" text,
    "Winning team" text,
    "Supporting" text
)