WSP08078

• File Number: 8277.500.10
• Description: Price and San Rafael Basin Unit - Colorado River Water Quality Improvement Program
• State: UT
• Basin: Colorado Mainstem
• Date: 12/1/1993
• Title: Planning Report / Final Environmental Impact Statement
• Water Supply Pro - Doc Type: EIS

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Summary

waters inside their boundaries. The seven Basin States initially developed
water quality standards that did not include numeric salinity criteria for the
Colorado River primarily because of technical constraints. In 1972, the States
agreed to a policy that called for the maintenance of salinity concentrations in
the Lower Colorado River System at or below existing levels, while the Upper
Basin States continued to develop their compact-apportioned waters. The
States suggested that Reclamation should have primary responsibility for
investigating, planning, and implementing the proposed Colorado River Basin
Salinity Control Program.

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The enactment of the Federal Water Pollution Control Act Amendments of 1972
affected salinity control in that the legislation was interpreted by EP A to
require numerical standards for salinity in the Colorado River. In response, the
Basin States founded the Colorado River Basin Salinity Control Forum (Forum)
to develop water quality standards including numeric salinity criteria and a
basinwide plan of implementation for salinity control. The Basin States held
public meetings on the proposed standards as required by the enacting
legislation.

The Forum recommended that the individual Basin States adopt the report,
Water Quality Standards for Salinity Including Numeric Criteria and Plan of
Implementation forSalinity Control, Colorado River System. The proposed
water quality standard called for maintenance of flow-weighted average total
dissolved solids concentrations of 723 mgIL below Hoover Dam, 747 mgIL below
Parker Dam, and 879 mgIL at Imperial Dam. Included in the plan of imple-
mentation were four salinity control units and possibly additional units, the
application of effluent limitations, the use of saline water whenever practicable,
and future studies. The standards are to be reviewed at 3-year intervals. All of
the Basin States adopted the Forum-recommended standards. The EPA
approved the standards.

Numeric criteria for the Lower Colorado River

Annual flow-weighted
concentration (mgIL)

Below Hoover Dam
Below Parker Dam
At Imperial Dam

723
747
879

In recognition of the salinity problem, Congress passed the Colorado River
Basin Salinity Control Act of 1974 (Public Law 93-320). Title II of the Act
authorized the construction of four salinity control units and the planning of
12 other units (including the Price-San Rafael Rivers Unit) as part of the
basinwide salinity control plan. The Price and San Rafael Rivers were
authorized for feasibility study by the Act. Public Law 98-569 amended the

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