Pub. L. 90-351, tit. I, pt. E, sec. 509

Sec. 509. Whenever the Administration, after reasonable notice and opportunity for hearing to an applicant or a grantee under this title, finds that, with respect to any payments made or to be made under this title, there is a substantial failure to comply with— (a) the provisions of this title; (b) regulations promulgated by the Administration under this title; or (c) a plan or application submitted in accordance with the provisions of this title; the Administration shall notify such applicant or grantee that further payments shall not be made (or in its discretion that further payments shall not be made for activities in which there is such failure), until there is no longer such failure.