WSP10235

• File Number: 8281.910
• Description: Colorado River Studies and Investigations -- Grand Valley Salinity Study
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 12/1/1976
• Author: Soil Cons Serv
• Title: Grand Valley Salinity Study - draft
• Water Supply Pro - Doc Type: Report/Study

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produced a series of reports on "The Mineral Quality Problem in the

Colorado River Basin" by the Environmental Protection Agency (1971).

The occurrence of sal inity in the Colorado River. is also documented by

the U. S. Bureau of Reclamation (1972 and 1974) Status Reports - Colorado

River Water Quality Improvement Program, and U. S. Geological Survey

Professional Paper 441, "Water Resources of the Upper Colorado River

Basin - Technical Report," by lorns and others (965).

The Federal Water Pollution Control Act Amendments of 1972, Pl92-500,

in Section 303 require the adoption of water quality standards appli-

cable to interstate waters. The Act's objective is "to restore and

maintain the chemical, physical, and biological integrity of the Nation's

waters" (Section 101), and the administrator is required, in cooperation

wi th other Federa 1, State, and loca I agencies, "to develop comprehens ive

programs for preventing, reducing, or eliminating the pollution of

navigable waters and ground waters" (Section 102La]). Pursuant to that

requirement, the Environmental Protection Agency on Oecember 18, 1974,

issued a regulation requiring the states of the Colorado River Basin to

adopt water quality standards for salinity, consisting of numeric criteria

and a plan of implementation for salinity control. The standards,

submitted for approval to the Environmental Protection Agency before

October 18, 1975, are to be reviewed at 3-year intervals and modified,

if appropriate.

Consistent with the regulation, the recommended flow-weighted average

annual numeric salinity criteria for three locations in the lower

main stem of the Colorado River System are:

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