Burlington officials have closed several beaches throughout the city, after test revealed high levels of cyanobacteria in certain areas of Lake Champlain. According to the city's beach closure tracker, as of Friday afternoon, all of Leddy Beach, North Beach, Texaco Beach and Blodgett Water Access Point have been closed. The south end of Blanchard Beach is on high alert, while the north side remains open. The Oak ledge beach cove is also on high alert.