The Administrator, in cooperation with the Director of the Indian Health Service, shall assess the need for sewage treatment works to serve Indian tribes, the degree to which such needs will be met through funds allotted to States under section
1285 of this title and priority lists under section
1296 of this title, and any obstacles which prevent such needs from being met. Not later than one year after February 4, 1987, the Administrator shall submit a report to Congress on the assessment under this subsection, along with recommendations specifying