Water Quality Standards for Surface Waters of the Sacramento River, San Joaquin River, and San Francisco Bay and Delta of the State of California: Notice of Availability

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 131

[OW-FRL-5058-2]

Water Quality Standards for Surface Waters of the Sacramento

River, San Joaquin River, and San Francisco Bay and Delta of the State

of California: Notice of Availability

AGENCY: Environmental Protection Agency.

ACTION: Notice of Availability.

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SUMMARY: This notice announces the availability of two documents

entitled, respectively, ``Alternative Formulation of the Salmon Smolt

Survival Index Criteria'', and ``Setting Goals for Salmon Smolt

Survival in the Delta''. The first of these documents presents EPA's

proposed alternative formulation of the salmon smolt survival index

criteria. The second document is a summary of the 3 scientific

workshops held on June 9, 17, and 29, 1994, and prepared by the

independent workshop facilitator. This notice also requests comments on

EPA's alternative formulation of the salmon smolt survival index

criteria. EPA is not soliciting any additional comments outside the

scope of this notice.

DATES: Copies of these documents are available beginning on August 26,

1994. Written comments on the specific issues raised in this document

pertaining to the salmon smolt survival index criteria will be accepted

until September 26, 1994.

ADDRESSES: Copies of the above documents can be obtained from, and

comments on these documents should be submitted to: Patrick Wright,

Bay/Delta Section Chief, W-2-4, Water Management Division,

Environmental Protection Agency, 75 Hawthorne Street, San Francisco,

California, 94105.

FOR FURTHER INFORMATION CONTACT: Patrick Wright, Bay/Delta Section

Chief, W-2-4, Water Management Division, Environmental Protection

Agency, 75 Hawthorne Street, San Francisco, California, 94105.

Telephone: (415) 744-1993.

SUPPLEMENTARY INFORMATION:

I. Background

On January 6, 1994, EPA published in the Federal Register a

Proposed Rule for water quality standards in the Sacramento River, San

Joaquin River, and San Francisco Bay and Delta of California (Bay/

Delta) (59 FR 810). The purpose of the rule would be to establish

certain water quality criteria for the Bay/Delta as authorized and

required by section 303 of the Clean Water Act (CWA). The federally-

proposed rule would replace portions of the State of California's water

quality standards that were disapproved by EPA on September 3, 1991.

Under the proposed regulations, three new sets of criteria would be

established: salinity criteria protecting the Estuarine Habitat and

other designated fish and wildlife uses, a second set of salinity

criteria (measured in electrical conductivity) to protect the Fish

Spawning designated use in the lower San Joaquin River, and a set of

salmon smolt survival index criteria to protect the Fish Migration and

Cold Fresh-Water Habitat designated uses in the estuary.

EPA held public hearings on the Proposed Rule during the weeks of

February 21, 1994 and February 28, 1994, and the comment period closed

on March 11, 1994. Subsequent to the close of the comment period, a

number of scientific workshops on the salmon smolt criteria were

sponsored and facilitated by a group of water users (including the

California Urban Water Users) and environmental organizations

(including the Bay Institute). The purpose of these workshops was to

consider and evaluate both the Proposed Rule and the major comments

received by EPA during the comment period. The workshop sponsors

invited EPA to attend the workshops, and EPA staff participated in

workshops on June 9, 17, and 29, 1994. The discussions at these

workshops are summarized in the August 10, 1994 document entitled

``Setting Goals for Salmon Smolt Survival in the Delta'' by Wim

Kimmerer. After reviewing the oral and written comments and the

discussions at these workshops, EPA has developed a proposed

alternative formulation of the salmon smolt survival index criteria.

In its Proposed Rule, EPA proposed salmon smolt survival index

criteria to protect certain of the designated uses. The survival index

quantifies and predicts the survival of salmon migrating through the

Delta. These survival indices are based on models developed by the U.S.

Fish and Wildlife Service (USFWS), and are based in large part on

experiments measuring and comparing smolt survival under a number of

different physical conditions of varying migration pathways, water

temperatures, flow rates, and rates of exports from the Delta.

The actual criteria in the Proposed Rule consisted of target salmon

smolt survival index values for the Sacramento and San Joaquin River

systems, varying according to the type of water year (critically dry,

dry, below normal, above normal, and wet). Success in attaining the

target values was to be predicted by using the USFWS models.

II. Alternative Formulation

EPA continues to believe that the USFWS models represent the best

available tools to analyze the success of migration of salmon through

the Delta, and provide an adequate scientific basis for establishing

water quality criteria that will protect the Fish Migration and Cold

Fresh-Water Habitat uses. However, as a result of its review of

comments on the Proposed Rule and its consideration of the discussions

at the scientific workshops described above, EPA is proposing an

alternative formulation of the salmon smolt survival index criteria.

Continuous function. The first major conceptual change in the

alternative formulation of the salmon smolt survival index criteria is

the use of continuous functions to describe the target index values.

The proposed rule had different target values for each of the five

water year types. This meant that, for example, all critically dry

years would have the same target index value, even though the

hydrological conditions within a critically dry year category could

vary substantially. A ``continuous function'' or ``sliding scale''

approach would recognize this intra-category variability by providing a

target index value that changes simultaneously with changes within

underlying hydrological conditions. For example, the target index value

in a ``wet'' critically dry year would be higher than the value for a

``dry'' critically dry year.

EPA received comment on both the proposed estuarine habitat

standard and the salmon smolt survival index criteria to the effect

that a continuous function relating the target values to a given

condition was more flexible than the use of five water year categories,

while still protecting the designated uses of the waterbodies.

Accordingly, the salmon smolt survival index criteria for both the

Sacramento River system and the San Joaquin River system have been

restated as continuous functions. On the Sacramento River system, the

target index values have been correlated to water temperature. On the

San Joaquin River system, the target index values have been correlated

to unimpaired water flow.

Performance standard. The second major proposed change in the

alternative formulation of the salmon smolt survival index criteria is

to move away from using the model to predict attainment, and instead to

measure attainment of the criteria using actual experimental data. In

the Proposed Rule, the criteria included the actual USFWS models for

the two river systems. Attainment of the criteria would be predicted by

evaluating the variables included in the model itself. That is, the

state could attain the criteria only by manipulating the variables

contained in the model equations such that target index values were

obtained. Although EPA believes the model contains the substantial

majority of the factors necessary for migrating smolt survival, EPA has

restated the criteria to be a true performance standard. The proposed

alternative formulation states an index value as the target criteria

(correlated, as indicated above, to either temperature or unimpaired

river flow). Attainment with the criteria, however, would no longer be

determined by manipulating the variables contained in the model, but

instead be based on real-time field monitoring to determine whether a

given set of implementation measures have actually attained the target

values in the criteria. This reformulation gives the state maximum

latitude to develop implementation measures that attain the target

index value. Further, the reformulation minimizes any statistical

deficiencies that may exist in the model by measuring actual measured

success in meeting the target, rather than modeled or predicted

success.

EPA believes that the model will continue to be critically

important to the standards process, in that it is the best mechanism

for developing and evaluating potential implementation measures.

However, by not formally including the model itself as a part of the

criteria, the alternative formulation gives those implementing the

standard maximum latitude to develop implementation approaches that

achieve the target index values.

More detailed discussion of the conceptual basis for the proposed

changes is found in the workshop summary entitled ``Setting Goals for

Salmon Smolt Survival in the Delta''. The specific proposed criteria

developed by EPA are contained and described in the document entitled

``Alternative Formulation of the Salmon Smolt Survival Index

Criteria.''

III. Public Participation

EPA desires full public participation in arriving at its final

decisions, and therefore solicits comments on all aspects of this

notice from all interested parties. However, EPA requests that comments

be limited to the specific issues raised by the two documents about the

salmon smolt survival index criteria. EPA does not intend to respond to

late comments submitted at this time which concern other aspects of the

Proposed Rule. Ample opportunity for such comment was already provided

at the public hearings and during the comment period that followed

publication of the Proposed Rule, and EPA is committed to signing a

final rule by December 15th, 1994. For those submitting comments,

whenever applicable, full supporting rationale, data, and detailed

analysis should be submitted to allow EPA to make maximum use of the

comments.

List of Subjects in 40 CFR Part 131

Environmental protection. Water pollution control. Water quality

standards. Water quality criteria.

Dated: August 18, 1994.

Robert Perciasepe,

Assistant Administrator for Water.

[FR Doc. 94-20953 Filed 8-25-94; 8:45 am]

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