flush tax
n.— «The U.S. Department of Defense has agreed to spend $22 million upgrading its wastewater- treatment plants throughout Maryland in lieu of paying the Ehrlich administration’s “flush tax”—a move that ends nearly two years of legal wrangling and makes money immediately available to reduce pollution flowing into the Chesapeake Bay.» —“‘Flush tax’ dispute ends” by Rona Kobell Baltimore Sun (Maryland) July 20, 2006. (source: Double-Tongued Dictionary)