Hudson Sloop Club and Apollonia Project cleanup of the Middle Ground Flats for the 5th Annual Riverkeeper Sweep, a day of service for the Hudson River. Volunteers will meet at Hudson Waterfront Park and then travel to the Flats by boat. Sweep volunteers are asked to wear sturdy shoes or boots, clothing that they can get dirty, and to bring a hat, eye protection, and other personal protective gear, sunscreen, a reusable water bottle and snack. Information at sweep@riverkeeper.org, nickzachos@gmail.com or stephen.merrett@gmail.com.