Sayville, New York, United States [CDP]; population was 16,550 in 1990; housing units was 5,560 in 1990; location is 40°45'N 73°5'W; land area is 5.53 square miles (3,537 acres); water area is 0.06 square miles (41 acres); FIPS code is 65409 [SourceCBP]