The chairman of the Florida Board of Education has been charged with illegally excavating in waters around his former property in the Florida Keys.Federal prosecutors late last month charged Tom Grady with a misdemeanor count of obstruction of navigable water, alleging he excavated at the property without a permit in April 2017.Grady has pleaded not guilty, court documents show. His attorney, David Oscar Markus, issued a statement saying Grady received approvals for the project from local, state and federal officials.