43 USC 390h - Program to investigate reclamation and reuse of wastewater and groundwater; general authority

(a) Program established 
The Secretary of the Interior (hereafter Secretary), acting pursuant to the Reclamation Act of 1902 (Act of June 17, 1902, 32 Stat. 388) and Acts amendatory thereof and supplementary thereto (hereafter Federal reclamation laws), is directed to undertake a program to investigate and identify opportunities for reclamation and reuse of municipal, industrial, domestic, and agricultural wastewater, and naturally impaired ground and surface waters, for the design and construction of demonstration and permanent facilities to reclaim and reuse wastewater, and to conduct research, including desalting, for the reclamation of wastewater and naturally impaired ground and surface waters.
(b) States included 
Such program shall be limited to the States and areas referred to in section 1 of the Reclamation Act of 1902 (Act of June 17, 1902, 32 Stat. 388) [43 U.S.C. 391] as amended, and the State of Hawaii.
(c) Agreements and regulations 
The Secretary is authorized to enter into such agreements and promulgate such regulations as may be necessary to carry out the purposes and provisions of sections 390h to 390h–23 of this title.
(d) San Luis Unit of Central Valley Project, California 
The Secretary shall not investigate, promote or implement, pursuant to sections 390h to 390h–23 of this title, any project intended to reclaim and reuse agricultural wastewater generated in the service area of the San Luis Unit of the Central Valley Project, California, except those measures recommended for action by the San Joaquin Valley Drainage Program in the report entitled A Management Plan for Agricultural Subsurface Drainage and Related Problems on the Westside San Joaquin Valley (September 1990).