The land transfer became the subject of a legal battle, which eventually led to congressional action. In August 1993, the Sierra Club Legal Defense Fund filed suit to block it, claiming that the federal government was required to conduct an environmental impact assessment before handing over the land. The group's interest in Kingman and Heritage islands was environmental: The lack of development and the wilderness-like aspect of the two islands had made them important to wildlife in the area. According to an Audubon Society survey at the time, more than 60 species of birds—including blue herons, eagles, snowy egrets, and ospreys—now lived on the islands. In December 1994, a United States district court agreed, and said the Park Service had violated the National Environmental Policy Act (NEPA) by transferring the land without conducting the assessment. D.C. officials sought the assistance of Congress. In July 1996, after a two-year lobbying effort, Congress passed the "National Children's Island Act of 1996" (P.L. 104-163, 110 Stat. 1416), which bypassed NEPA and transferred the land to the District of Columbia. The legislation specified, however, that the city could use the land only for a children's park. Congress acted after National Children's Island, Inc., unveiled plans for a scaled-back, $150 million development which was characterized as a "mini-Epcot Center". The company said it would begin construction within 14 months of the passage of the legislation.