Millions enjoy Lake Lanier each year, and lake groups now want those visitors to return the favor with some litter cleanup. This year’s Shore Sweep will be 8 a.m. to 1 p.m. Sept. 27, with drop-off points at marinas across the lake in Hall, Dawson, Forsyth and Gwinnett counties. “We typically get 1,000 volunteers on the day of the event,” said Joanna Cloud, executive director of the Lake Lanier Association, which puts on the event.