[Code of Federal Regulations]
[Title 40, Volume 21]
[Revised as of July 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR131.37]

[Page 464-467]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 131_WATER QUALITY STANDARDS--Table of Contents
 
         Subpart D_Federally Promulgated Water Quality Standards
 
Sec.  131.37  California.

    (a) Additional criteria. The following criteria are applicable to 
waters specified in the Water Quality Control Plan for Salinity for the 
San Francisco Bay/Sacramento-San Joaquin Delta Estuary, adopted by the 
California State Water Resources Control Board in State Board Resolution 
No. 91-34 on May 1, 1991:
    (1) Estuarine habitat criteria. (i) General rule. (A) Salinity 
(measured at the surface) shall not exceed 2640 micromhos/centimeter 
specific conductance at 25 [deg]C (measured as a 14-day moving average) 
at the Confluence of the Sacramento and San Joaquin Rivers throughout 
the period each year from February 1 through June 30, and shall not 
exceed 2640 micromhos/centimeter specific conductance at 25 [deg]C 
(measured as a 14-day moving average) at the specific locations noted in 
Table 1 near Roe Island and Chipps Island for the number of days each 
month in the February 1 to June 30 period computed by reference to the 
following formula:

Number of days required in Month X = Total number of days in Monthx* (1 
    - 1/(1+e\K\)

where

K = A + (B*natural logarithm of the previous month's 8-River Index);
A and B are determined by reference to Table 1 for the Roe Island and 
Chipps Island locations;
x is the calendar month in the February 1 to June 30 period;
and e is the base of the natural (or Napierian) logarithm.


Where the number of days computed in this equation in paragraph 
(a)(1)(i)(A) of this section shall be rounded to the nearest whole 
number of days. When the previous month's 8-River Index is less than 
500,000 acre-feet, the number of days required for the current month 
shall be zero.

   Table 1. Constants applicable to each of the monthly equations to determine monthly requirements described.
----------------------------------------------------------------------------------------------------------------
                                                           Chipps Island             Roe Island (if triggered)
                     Month X                     ---------------------------------------------------------------
                                                         A               B               A               B
----------------------------------------------------------------------------------------------------------------
Feb.............................................            -\1\            -\1\          -14.36          +2.068
Mar.............................................         -105.16         +15.943          -20.79          +2.741
Apr.............................................          -47.17          +6.441          -28.73          +3.783
May.............................................          -94.93         +13.662          -54.22          +6.571
June............................................          -81.00          +9.961         -92.584        +10.699
----------------------------------------------------------------------------------------------------------------
\1\ Coefficients for A and B are not provided at Chipps Island for February, because the 2640 micromhos/cm
  specific conductance criteria must be maintained at Chipps Island throughout February under all historical 8-
  River Index values for January.

    (B) The Roe Island criteria apply at the salinity measuring station 
maintained by the U.S. Bureau of Reclamation at Port Chicago (km 64). 
The Chipps Island criteria apply at the Mallard Slough Monitoring Site, 
Station D-10 (RKI RSAC-075) maintained by the California Department of 
Water Resources. The Confluence criteria apply at the Collinsville 
Continuous Monitoring Station C-2 (RKI RSAC-081) maintained by the 
California Department of Water Resources.
    (ii) Exception. The criteria at Roe Island shall be required for any 
given month only if the 14-day moving average salinity at Roe Island 
falls below 2640 micromhos/centimeter specific conductance on any of the 
last 14 days of the previous month.
    (2) Fish migration criteria--(i) General rule--(A) Sacramento River. 
Measured Fish Migration criteria values for the Sacramento River shall 
be at least the following:


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At temperatures less than below 61 [deg]F: SRFMC = 1.35
At temperatures between 61 [deg]F and 72 [deg]F: SRFMC = 6.96-.092 * 
    Fahrenheit temperature
At temperatures greater than 72 [deg]F: SRFMC = 0.34


where SRFMC is the Sacramento River Fish Migration criteria value. 
Temperature shall be the water temperature at release of tagged salmon 
smolts into the Sacramento River at Miller Park.
    (B) San Joaquin River. Measured Fish Migration criteria values on 
the San Joaquin River shall be at least the following:

For years in which the SJVIndex is 2.5: SJFMC = (-0.012) + 
    0.184*SJVIndex
In other years: SJFMC = 0.205 + 0.0975*SJVIndex


where SJFMC is the San Joaquin River Fish Migration criteria value, and 
SJVIndex is the San Joaquin Valley Index in million acre feet (MAF)
    (ii) Computing fish migration criteria values for Sacramento River. 
In order to assess fish migration criteria values for the Sacramento 
River, tagged fall-run salmon smolts will be released into the 
Sacramento River at Miller Park and captured at Chipps Island, or 
alternatively released at Miller Park and Port Chicago and recovered 
from the ocean fishery, using the methodology described in this 
paragraph (a)(2)(ii). An alternative methodology for computing fish 
migration criteria values can be used so long as the revised methodology 
is calibrated with the methodology described in this paragraph 
(a)(2)(ii) so as to maintain the validity of the relative index values. 
Sufficient releases shall be made each year to provide a statistically 
reliable verification of compliance with the criteria. These criteria 
will be considered attained when the sum of the differences between the 
measured experimental value and the stated criteria value (i.e., 
measured value minus stated value) for each experimental release 
conducted over a three year period (the current year and the previous 
two years) shall be greater than or equal to zero. Fish for release are 
to be tagged at the hatchery with coded-wire tags, and fin clipped. 
Approximately 50,000 to 100,000 fish of smolt size (size greater than 75 
mm) are released for each survival index estimate, depending on expected 
mortality. As a control for the ocean recovery survival index, one or 
two groups per season are released at Benecia or Pt. Chicago. From each 
upstream release of tagged fish, fish are to be caught over a period of 
one to two weeks at Chipps Island. Daylight sampling at Chipps Island 
with a 9.1 by 7.9 m, 3.2 mm cod end, midwater trawl is begun 2 to 3 days 
after release. When the first fish is caught, full-time trawling 7 days 
a week should begin. Each day's trawling consists of ten 20 minute tows 
generally made against the current, and distributed equally across the 
channel.
    (A) The Chipps Island smolt survival index is calculated as:

SSI=R/MT(0.007692)

where

R=number of recaptures of tagged fish
M=number of marked (tagged) fish released
T=proportion of time sampled vs total time tagged fish were passing the 
site (i.e. time between first and last tagged fish recovery)


Where the value 0.007692 is the proportion of the channel width fished 
by the trawl, and is calculated as trawl width/channel width.
    (B) Recoveries of tagged fish from the ocean salmon fishery two to 
four years after release are also used to calculate a survival index for 
each release. Smolt survival indices from ocean recoveries are 
calculated as:

OSI=R1/M1/R2/M2

where

R1=number of tagged adults recovered from the upstream 
release
M1=number released upstream
R2=number of tagged adults recovered from the Port Chicago 
release
M2=number released at Port Chicago

    (1) The number of tagged adults recovered from the ocean fishery is 
provided by the Pacific States Marine Fisheries Commission, which 
maintains a port sampling program.
    (2) [Reserved]
    (iii) Computing fish migration criteria values for San Joaquin 
River. In order to assess annual fish migration criteria

[[Page 466]]

values for the San Joaquin River, tagged salmon smolts will be released 
into the San Joaquin River at Mossdale and captured at Chipps Island, or 
alternatively released at Mossdale and Port Chicago and recovered from 
the ocean fishery, using the methodology described in paragraph 
(a)(2)(iii). An alternative methodology for computing fish migration 
criteria values can be used so long as the revised methodology is 
calibrated with the methodology described below so as to maintain the 
validity of the relative index values. Sufficient releases shall be made 
each year to provide a statistically reliable estimate of the SJFMC for 
the year. These criteria will be considered attained when the sum of the 
differences between the measured experimental value and the stated 
criteria value (i.e., measured value minus stated value) for each 
experimental release conducted over a three year period (the current 
year and the previous two years) shall be greater than or equal to zero.
    (A) Fish for release are to be tagged at the hatchery with coded-
wire tags, and fin clipped. Approximately 50,000 to 100,000 fish of 
smolt size (size greater than 75 mm) are released for each survival 
index estimate, depending on expected mortality. As a control for the 
ocean recovery survival index, one or two groups per season are released 
at Benicia or Pt. Chicago. From each upstream release of tagged fish, 
fish are to be caught over a period of one to two weeks at Chipps 
Island. Daylight sampling at Chipps Island with a 9.1 by 7.9 m, 3.2 mm 
cod end, midwater trawl is begun 2 to 3 days after release. When the 
first fish is caught, full-time trawling 7 days a week should begin. 
Each day's trawling consists of ten 20 minute tows generally made 
against the current, and distributed equally across the channel.
    (B) The Chipps Island smolt survival index is calculated as:

SSI=R/MT(0.007692)

where

R=number of recaptures of tagged fish
M=number of marked (tagged) fish released
T=proportion of time sampled vs total time tagged fish were passing the 
site (i.e. time between first and last tagged fish recovery)

Where the value 0.007692 is the proportion of the channel width fished 
by the trawl, and is calculated as trawl width/channel width.
    (C) Recoveries of tagged fish from the ocean salmon fishery two to 
four years after release are also used to calculate a survival index for 
each release. Smolt survival indices from ocean recoveries are 
calculated as:

OSI=R1/M1 / R2/M2

where

R1=number of tagged adults recovered from the upstream 
release
M1=number released upstream
R2=number of tagged adults recovered from the Port Chicago 
release
M2=number released at Port Chicago

    (1) The number of tagged adults recovered from the ocean fishery is 
provided by the Pacific States Marine Fisheries Commission, which 
maintains a port sampling program.
    (2) [Reserved]
    (3) Suisun marsh criteria. (i) Water quality conditions sufficient 
to support a natural gradient in species composition and wildlife 
habitat characteristic of a brackish marsh throughout all elevations of 
the tidal marshes bordering Suisun Bay shall be maintained. Water 
quality conditions shall be maintained so that none of the following 
occurs: Loss of diversity; conversion of brackish marsh to salt marsh; 
for animals, decreased population abundance of those species vulnerable 
to increased mortality and loss of habitat from increased water 
salinity; or for plants, significant reduction in stature or percent 
cover from increased water or soil salinity or other water quality 
parameters.
    (ii) [Reserved]
    (b) Revised criteria. The following criteria are applicable to state 
waters specified in Table 1-1, at Section (C)(3) (``Striped Bass--
Salinity : 3. Prisoners Point--Spawning) of the Water Quality Control 
Plan for Salinity for the San Francisco Bay--Sacramento/San Joaquin 
Delta Estuary, adopted by the California State Water Resources Control 
Board in State Board Resolution No. 91-34 on May 1, 1991:

[[Page 467]]



--------------------------------------------------------------------------------------------------------------------------------------------------------
                              Sampling site Nos (I--                                                      San Joaquin
          Location                    A/RKI)            Parameter       Description       Index type     Valley Index        Dates            Values
--------------------------------------------------------------------------------------------------------------------------------------------------------
San Joaquin River at Jersey   D15/RSAN018,           Specific.......  14-day running   Not Applicable.  2.5  April 1 to May   0.44 micro-
 Point, San Andreas Landing,  C4/RSAN032,            Conductance....   average of                        MAF             31.              mhos.
 Prisoners Point, Buckley     D29/RSAN038,           @ 25 [deg]C....   mean daily for
 Cove, Rough and Ready        P8/RSAN056,                              the period not
 Island, Brandt Bridge,       -/RSAN062,                               more than
 Mossdale, and Vernalis.      C6/RSAN073,                              value shown,
                              C7/RSAN087,                              in mmhos.
                              C10/RSAN112
San Joaquin River at Jersey   D15/RSAN018,           Specific         14-day running   Not Applicable.  <=2.5 MAF       April 1 to May   0.44 micro-
 Point, San Andreas Landing   C4/RSAN032,             Conductance.     average of                                        31.              mhos.
 and Prisoners Point.         D29/RSAN038                              mean daily for
                                                                       the period not
                                                                       more than
                                                                       value shown,
                                                                       in mmhos.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    (c) Definitions. Terms used in paragraphs (a) and (b) of this 
section, shall be defined as follows:
    (1) Water year. A water year is the twelve calendar months beginning 
October 1.
    (2) 8-River Index. The flow determinations are made and are 
published by the California Department of Water Resources in Bulletin 
120. The 8-River Index shall be computed as the sum of flows at the 
following stations:
    (i) Sacramento River at Band Bridge, near Red Bluff;
    (ii) Feather River, total inflow to Oroville Reservoir;
    (iii) Yuba River at Smartville;
    (iv) American River, total inflow to Folsom Reservoir;
    (v) Stanislaus River, total inflow to New Melones Reservoir;
    (vi) Tuolumne River, total inflow to Don Pedro Reservoir;
    (vii) Merced River, total inflow to Exchequer Reservoir; and
    (viii) San Joaquin River, total inflow to Millerton Lake.
    (3) San Joaquin Valley Index. (i) The San Joaquin Valley Index is 
computed according to the following formula:

ISJ=0.6X+0.2Y and 0.2Z

where

ISJ=San Joaquin Valley Index
X=Current year's April-July San Joaquin Valley unimpaired runoff
Y=Current year's October-March San Joaquin Valley unimpaired runoff
Z=Previous year's index in MAF, not to exceed 0.9 MAF

    (ii) Measuring San Joaquin Valley unimpaired runoff. San Joaquin 
Valley unimpaired runoff for the current water year is a forecast of the 
sum of the following locations: Stanislaus River, total flow to New 
Melones Reservoir; Tuolumne River, total inflow to Don Pedro Reservoir; 
Merced River, total flow to Exchequer Reservoir; San Joaquin River, 
total inflow to Millerton Lake.
    (4) Salinity. Salinity is the total concentration of dissolved ions 
in water. It shall be measured by specific conductance in accordance 
with the procedures set forth in 40 CFR 136.3, Table 1B, Parameter 64.

[60 FR 4707, Jan. 24, 1995]

[[Page 468]]