[Federal Register Volume 59, Number 165 (Friday, August 26, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-20953]


[[Page Unknown]]

[Federal Register: August 26, 1994]


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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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