BOARD01043

• Board Meeting Date: 3/10/1998
• Description: WSP Section - Colorado River Basin Issues - Colorado River Basin Salinity Control Program: I. Triennial Review, II. Standards Discussion
• Board Meetings - Doc Type: Memo

"".--f

, ~

~

I~

March 10-11, 1998
Agenda Item 18d
Page 2 of3

.

Basin which were subsequently adopted by each of the seven basin states and approved by the US
EP A. The Colorado River Basin salinity standard consists of three parts:
1) The numeric criteria establishing specific maximum levels ofTDS (annual flow weighted
average) at three measuring stations in the Lower Basin (723 mg/l, 747 mg/I, and 879 mg/I at
Hoover, Parker, and Imperial Dams respectively).
2) A plan of implementation setting out proj ect schedules and funding requirements needed to
keep from exceeding the numeric criteria as water development progressed in the Upper Basin.
3) Forum drafted, state adopted policies governing the issuance ofNPDES permits for point
source discharges of salinity into the Colorado River system.
The standards were adopted pursuant to the federal Clean Water Act which requires that all water
quality standards be reviewed every 3 years to consider the need for modification of the standards.

DISCUSSION

i. Triennial review.
The Forum has conducted reviews of the Colorado River Basin salinity standard every three years
since 1978 with the most recent review report being issued in 1996. Each of the recent reviews has
consisted of the following elements: .'-
- determining current salinity and hydrologic conditions,
- re-estimating future anticipated depletions of the basin water supply,
_ modeling projected salinity levels at the numeric criteria stations and determining the amount
of salt load which must be controlled to remain below the numeric criteria under average
hydrologic conditions,
- demonstrating the economic benefits of controlling salinity, and
_ revising the plan of implementation to remove the necessary amount of salt in a cost-effective
manner.

A schedule has been developed and initial work has begun on the 1999 review. Staff will be
participating in the analysis, report writing, and public participation efforts over the next 18 months.
The Report documenting the review process and findings will be approved by the Forum and
submitted to each of the states, which will then adopt the review under each state's own procedures
and submit it to EPA for approval. In Colorado the staffs of the CWCB and Water Quality Control
Division coordinate during the review and the Water Quality Control Commission ultimately adopts
as a regulation and policy portions of the Forum approved Review, and the water quality standards
for salinity thus are reaffirmed as state law.

ii. Standards
In previous reviews the Forum has received little, if any, information that would cause it to re-

(;,'SIlMIUEIlISOAJD/lCEM\9IM.U.II.WI'D
___ioJ,I!1911

tt.,