On that day, the New York State Energy Research and Development Authority (the “Authority”) issued $23.4 million in bonds to fund residential energy-efficiency projects. The bonds were rated AAA, thanks to a financial guaranty from the New York State Environmental Facilities Corporation (EFC). What was astonishing was that the EFC, which manages the Clean Water State Revolving Fund (CWSRF) in New York, used legal authority under the Clean Water Act-not the Clean Air Act-to effectuate the guaranty! In effect, the EFC used the net assets of its CWSRF program to credit enhance the bonds of its sister agency that does energy projects. This is the first-ever transaction to provide linkage between clean energy and clean water programs.