Home inspection in St. Louis, Missouri.

Why St. Louis homes need a local read

St. Louis is an independent Missouri city, outside any county, near where the Mississippi and Missouri rivers meet.

History: Founded in 1764, incorporated as a city in 1822, and separate from St. Louis County since 1877.

Housing: Lafayette Square has houses that blend Greek Revival, Federal and Italianate styles, and Laclede's Landing has cobblestone streets and brick and cast-iron warehouses.

Around town: Lafayette Square, Laclede's Landing, Central West End, The Hill, Benton Park West, Tower Grove Park and Union Station.

Setting: The city rests on bluffs and terraces 100 to 200 feet above the west bank of the Mississippi, over limestone and dolomite, with karst sinkholes and caves concentrated south of downtown.

Water, flooding and moisture in St. Louis

Water nearby: The city sits on the west bank of the Mississippi, the Missouri River joins it nearby, and the River des Peres was channelized or put underground in the 1920s and early 1930s.

Flood history: The Mississippi reached its highest level in over 150 years in 1973, and the lower River des Peres had some of the worst flooding of the Great Flood of 1993.

Parts of the city are karst, with sinkholes and caves south of downtown, and springs are still visible along the riverfront.

EPA's Map of Radon Zones places City of St. Louis in Zone 2 (predicted average indoor levels of 2 to 4 pCi/L). EPA notes that homes vary within any zone, so the map does not predict a single house.

Sources for the facts on this page

• en.wikipedia.org: St. Louis
• epa.gov: epa map radon zones