Are you building on wetlands? Is the real estate you are buying listed by the US Fish and Wildlife Service as a wetlands on its maps? If your property or prospective purchase has been identified as a wetlands then think twice before developing the property. Before buying property for development, check this link:
http://www.fws.gov/wetlands/Data/Web-Map-Services.html
You can also download a KML file that you can launch in Google Earth:
http://www.fws.gov/wetlands/Data/Google-Earth.html
A wetlands classification will not show up on title searches or a standard Phase I. Years after your project is complete the U S Army Corps of Engineers may demand a fine of up to $37,500, not to exceed $187,500 per day violation. In addition to checking these websites, you should also consider hiring a qualified wetlands consultant to make a determination in case the Corps comes knocking on the door some day.