Lake Elmo Airport (FAA LID: 21D) is a public airport located just outside the city of Lake Elmo in Washington County, Minnesota, United States, about 12 miles[3] east of the central business district of St. Paul.

[5] Lake Elmo covers an area of 640 acres (259 ha) at an elevation of 932 feet (284 m) above mean sea level.

[1] For the 12-month period ending July 31, 2019, the airport had 26,498 aircraft operations, an average of 73 per day: 95% general aviation, 4% air taxi, and 1% military.

[1][2] The Lake Elmo Airport is connected to the contamination at the Baytown Township Ground Water Plume Superfund site.

[citation needed] The site is listed due to trichloroethylene contamination of a groundwater aquifer used for local drinking water supplies.