Dataset describes measurements of host-associated qPCR genetic markers along with other water quality parameters and precipitation from samples collected at marine, estuary, and freshwater recreational sites. Additional details provided in attached Dataset Description document. “This research dataset has been reviewed in accordance with U.S. Environmental Protection Agency (U.S. EPA), Office of Research and Development, and approved for release. Mention of brand names or vendors does not constitute an endorsement of products or services by the U.S. EPA.”