[Code of Federal Regulations]
[Title 43, Volume 1]
[Revised as of October 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 43CFR11.93]

[Page 275-281]
 
                    TITLE 43--PUBLIC LANDS: INTERIOR
 
PART 11--NATURAL RESOURCE DAMAGE ASSESSMENTS--Table of Contents
 
                    Subpart F--Post-Assessment Phase
 
Sec. 11.93  Post-assessment phase--restoration plan.

    (a) Upon determination of the amount of the award of a natural 
resource damage claim as authorized by section 107(a)(4)(C) of CERCLA, 
or sections 311(f)(4) and 311(f)(5) of the CWA, the authorized official 
shall prepare a Restoration Plan as provided in section 111(i) of 
CERCLA. The plan shall be based upon the Restoration and Compensation 
Determination Plan described in Secs. 11.81 of this part. The Plan shall 
describe how the monies will be used to address natural resources, 
specifically what restoration, rehabilitation, replacement, or 
acquisition of the equivalent resources will occur. When damages for 
compensable value have been awarded, the Plan shall also describe how 
monies will be used to address the services that are lost to the public 
until restoration, rehabilitation, replacement, and/or acquisition of 
equivalent resources is completed. The Restoration Plan shall be 
prepared in accordance with the guidance set forth in Sec. 11.81 of this 
part.
    (b) No restoration activities shall be conducted by Federal agencies 
that would incur ongoing expenses in excess of those that would have 
been incurred under baseline conditions and that cannot be funded by the 
amount included in the separate account established pursuant to 
Sec. 11.92(a) of this part unless such additional monies are 
appropriated through the normal appropriations process.
    (c) Modifications may be made to the Restoration Plan as become 
necessary as the restoration proceeds. Significant modifications shall 
be made available for review by any responsible party,

[[Page 276]]

any affected natural resource trustees, other affected Federal or State 
agencies or Indian tribes, and any other interested members of the 
public for a period of at least 30 days, with reasonable extensions 
granted as appropriate, before tasks called for in the modified plan are 
begun.
    (d) If the measure of damages was determined in accordance with 
subpart D, the restoration plan may describe actions to be taken that 
are to be financed from more than one damage award, so long as the 
actions are intended to address the same or similar resource injuries as 
those identified in each of the subpart D assessment procedures that 
were the basis of the awards.

[51 FR 27725, Aug. 1, 1986, as amended at 52 FR 9100, Mar. 20, 1987; 53 
FR 5176, Feb. 22, 1988; 59 FR 14287, Mar. 25, 1994]

Appendix I to Part 11--Methods for Estimating the Areas of Ground Water 
       and Surface Water Exposure During the Preassessment Screen

    This appendix provides methods for estimating, as required in 
Sec. 11.25 of this part, the areas where exposure of ground water or 
surface water resources may have occurred or are likely to occur. These 
methods may be used in the absence of more complete information on the 
ground water or surface water resources.

                              Ground Water

    The longitudinal path length (LPL) factors in table 1 are to be 
applied in estimating the area potentially exposed downgradient of the 
known limit of exposure or of the boundary of the site. Estimates of 
lateral path width (LPW) are to be used when the LPW exceeds the width 
of the plume as determined from available data, or when the width of the 
plume at the boundary of the site is estimated as less than the LPW. In 
the absence of data to the contrary, the largest values of LPL and LPW 
consistent with the geohydrologic data available shall be used to make 
the estimates required in the preassessment screen. An example 
computation using the LPL and LPW factors follows table 1.

            Table 1--Factors for Estimation of Areas Potentially Exposed Via the Ground Water Pathway
----------------------------------------------------------------------------------------------------------------
                                                Hydraulic
                               Hyd. conductiv-  gradient   Time since       Longitudinal
         Aquifer type            ity/porosity   estimate     release         path length  Lateral path width (in
                               factor (miles/    (feet/     began (in         (in feet)            feet)
                                    year)         mile)      years)
----------------------------------------------------------------------------------------------------------------
Sand.........................              50  x.........  x.........   =   ............  LPW=0.2LPL
Sand+silt....................             0.5  x.........  x.........   =   ............  LPW=0.3LPL
Gravel.......................            6000  x.........  x.........   =   ............  LPW=0.2LPL
Sandstone....................            0.01  x.........  x.........   =   ............  LPW=0.4LPL
Shale........................        3x10-\6\  x.........  x.........   =   ............  LPW=0.8LPL
Karst Limestone or Dolomite..              10  x.........  x.........   =   ............  LPW=0.2LPL
Limestone or Dolomite........            0.01  x.........  x.........   =   ............  LPW=0.4LPL
Fractured Crystalline Rocks..             0.3  x.........  x.........   =   ............  LPW=0.3LPL
Dense Crystalline Rocks......          1x10-5  x.........  x.........   =   ............  LPW=0.8LPL
----------------------------------------------------------------------------------------------------------------

 Example of Computation for Estimating the Area Potentially Exposed via 
                          Ground Water Pathway

    A release of hazardous substances occurs from a facility located in 
a glacial valley. Available data indicate the release may have occurred 
intermittently over a period of almost 1 year, although only one well 
about 300 feet downgradient of the facility boundary had detectable 
quantities of contaminants. The contaminated well is screened in the 
water table aquifer composed of gravelly sands. The facility boundary 
nearest the contaminated well is almost 3,000 feet in length, but a 
review of available data determined the release is probably localized 
along a 500-foot section of the boundary where a stream leaves the 
facility. Available water table data indicate hydraulic gradients in the 
valley range from 0.005 feet/mile up to 0.25 feet/mile near pumping 
wells. No pumping wells are known to be located near the release, and a 
mean hydraulic gradient of 0.1 feet/mile is estimated in the vicinity of 
the release site.

[[Page 277]]

Using the gravel factor from table 1, the LPL and LPW are estimated:

6000x0.1x1=600 feet  (LPL)
      and
600x0.2=120 feet  (LPW).

Since the estimated LPW (120 feet) is less than the plume width (500 
feet) determined from other available data, the greater number is used 
to compute the area potentially exposed:
    (1) 600 feetx500 feet=300,000 square feet (about 6.9 acres). The 
available information allows an initial determination of area 
potentially exposed via the ground water pathway to be estimated:
    (2) 300 feetx500 feet=150,000 square feet (about 3.5 acres).
    The total area potentially exposed is the sum of (1) and (2):

6.9+3.5=10.4 acres.

                              Surface Water

    The area of surface water resources potentially exposed should be 
estimated by applying the principles included in the examples provided 
below.

    Example 1: A release occurs and most of the oil or hazardous 
substance enters a creek, stream, or river instantaneously or over a 
short time interval (pulse input is assumed). The maximum concentration 
at any downstream location, past the initial mixing distance, is 
estimated by:

Cp=25(Wi)/(T0.7 Q)


where Cp is the peak concentration, in milligrams/liter (mg/
L),

Wi is the total reported (or estimated) weight of the 
          undiluted substance released, in pounds,
Q is the discharge of the creek, stream, or river, in cubic feet/second, 
          and
T is the time, in hours, when the peak concentration is estimated to 
          reach a downstream location L, in miles from the entry point.

    The time T may be estimated from:

T=1.5(L)/Vs

where T and L are defined as above and

Vs is the mean stream velocity, in feet per second.

The mean stream velocity may be estimated from available discharge 
measurements or from estimates of slope of the water surface S (foot 
drop per foot distance downstream) and estimates of discharge Q (defined 
above) using the following equations:

for pool and riffle reaches 
          Vs=0.38(Q0.40)(S0.20), or
for channel-controlled reaches 
          Vs=2.69(Q0.26)(S0.28).

Estimates of S may be made from the slope of the channel, if necessary.
    As the peak concentrations become attenuated by downstream 
transport, the plume containing the released substance becomes 
elongated. The time the plume might take to pass a particular point 
downstream may be estimated using the following equation:

Tp=9.25x106 Wi/(QCp)

where

Tp is the time estimate, in hours, and Wi, 
Cp, and Q are defined above.

    Example 2: A release occurs and most of the oil or hazardous 
substance enters a creek, stream, or river very slowly or over a long 
time period (sustained input assumed). The maximum concentration at any 
downstream location, past the initial mixing distance, is estimated by:

Cp=C(q)/(Q+


where Cp and Q are defined above,

C is the average concentration of the released substance during the 
          period of release, in mg/L, and
q is the discharge rate of the release into the streamflow, in cubic 
          feet/second.

For the above computations, the initial mixing distance may be estimated 
by:

Lm=(1.7x10-5)Vs B2/
          (D1.5 S0.5)

where

Lm is the initial mixing distance, in miles,
Vs is defined above,
B is the average stream surface width, in ft,
D is the mean depth of the stream, in ft, and
S is the estimated water-surface slope, in ft/ft.
    Example 3: A release occurs and the oil or hazardous substance 
enters a pond, lake, reservoir, or coastal body of water. The 
concentration of soluble released substance in the surface water body 
may be estimated by:

Cp=CVc/(Vw+Vc)


where

Cp and C are defined above,
Vc is the estimated total volume of substance released, in 
          volumetric units, and
Vw is the estimated volume of the surface water body, in the 
          same volumetric units used for Vc.

[51 FR 27725, Aug. 1, 1986, as amended at 52 FR 9100, Mar. 20, 1987]

Appendix II to Part 11--Format for Data Inputs and Modifications to the 
                                NRDAM/CME

    This appendix specifies the format for data inputs and modifications 
to the NRDAM/CME under Sec. 11.41. Consult the back of this appendix for 
definitions.

[[Page 278]]

                    Starting Point for the NRDAM/CME

    The NRDAM/CME begins its calculations at the point that the released 
substance entered water in an area represented by its geographic 
database. Any water within the geographic boundaries of the NRDAM/CME is 
a ``coastal or marine environment.'' The authorized official must 
determine all data inputs and modifications as of the time and location 
that the released substance entered a coastal or marine environment. In 
the case of a release that began in water in an area within the 
boundaries of the NRDAM/CME, this point will be the same as the point of 
the release. However, for releases that begin on land or that begin 
outside the boundaries of the NRDAM/CME, this point will not be the 
point of the release but rather the point at which the released 
substance migrates into a coastal or marine environment.

                          Required Data Inputs

    Documentation of the source of the data inputs; and

                          Identity of Substance

    For release of single substance:
    Name of the substance that entered a coastal or marine environment 
as it appears in Table 7.1, Volume I of the NRDAM/CME technical document 
(incorporated by reference, see Sec. 11.18).
    For releases of two or more substances or a release of a mixture of 
two or more substances:
    Name of only one of the substances that entered a coastal or marine 
environment as it appears in Table 7.1, Volume I of the NRDAM/CME 
technical document.

                             Mass or Volume

    For release of single substance:
    Mass or volume of identified substance that entered a coastal or 
marine environment stated in tonnes, barrels, gallons, liters, pounds, 
or kilograms.
    For releases of two or more substances or a release of a mixture of 
two or more substances:
    Mass or volume of the one identified substance (rather than total 
mass) that entered a coastal or marine environment stated in tonnes, 
barrels, gallons, liters, pounds, or kilograms.

                                Duration

    Length of time over which the identified substance entered a coastal 
or marine environment stated in hours.

                                  Time

    Year, month, day, and hour when the identified substance first 
entered a coastal or marine environment.

                                Location

    Latitude and longitude, stated in degrees and decimal minutes, where 
the identified substance entered a coastal or marine environment.

                                  Winds

    At least one set of data on prevailing wind conditions for each day 
of the 30-day period beginning 24 hours before the identified substance 
entered a coastal or marine environment. Each set must include:
    Wind velocity stated in knots or meters per second; and
    Corresponding wind direction stated in the degree angle of the 
wind's origin.

[One possible source of information is the National Climatic Data 
Center, Asheville, NC (703) 271-4800.]

                            Response Actions

    If removed from water surface:
    A rectangular geographic area encompassing the surface water area 
over which the released substance was likely to have spread, stated in 
terms of the northern- and southern-most latitude, and the eastern- and 
western-most longitude;
    One or more time frames for removal stated in terms of the number of 
days and hours after the identified substance entered a coastal or 
marine environment that removal began and ended; and
    For each time frame, volume of the identified substance removed from 
the water surface (not the total volume of contaminated water or 
sediments removed) stated in barrels, gallons, or cubic meters.
    If removed from shoreline:
    A rectangular geographic area encompassing the shoreline area over 
which the released substance was likely to have spread, stated in terms 
of the northern- and southern-most latitude, and the eastern- and 
western-most longitude;
    One or more time frames for removal stated in terms of the number of 
days and hours after the identified substance entered a coastal or 
marine environment that removal began and ended; and
    For each time frame, volume of the identified substance removed (not 
the total volume of contaminated water or sediments removed) stated in 
barrels, gallons, or cubic meters.

                                Closures

    Documentation that the closure was ordered by an appropriate agency 
as a result of the release;
    Province(s) in which closure occurred; and
    For beaches:
    Whether the beach was Federal or State (including municipal or 
county);

[[Page 279]]

    Number of days of closure stated by calendar month; and
    Length of shoreline closed, stated in kilometers, for each month in 
which closure occurred.
    For fisheries and shellfish harvest areas:
    Whether area closed was seaward open water, landward open water, or 
structured;
    Number of days of closure; and
    Area closed stated in square kilometers.
    For furbearer hunting or trapping areas and waterfowl hunting areas:
    Number of days of closure; and
    Area closed stated in square kilometers.

                         Implicit Price Deflator

    Quarterly implicit price deflator for the Gross National Product 
(base year 1992) for the quarter in which the identified substance 
entered a coastal or marine environment. [See the Survey of Current 
Business, published by the U.S. Department of Commerce/Bureau of 
Economic Analysis, 1441 L Street, NW, Washington, D.C., 20230, (202) 
606-9900.]

                                Currents

    For a rectangular geographic area encompassing the area affected by 
the release stated in terms of the northern- and southern-most latitude, 
and the eastern- and western-most longitude:
    At least one set of data concerning background (mean) current 
consisting of--
    An east-west (U) velocity stated in centimeters per second or knots;
    A north-south (V) velocity stated in centimeters per second or 
knots; and
    Latitude and longitude of the origin of the U and V velocity 
components.
    At least one set of data concerning tidal current at time of flood 
stage (i.e., rising tide) consisting of--
    An east-west (U) velocity stated in centimeters per second or knots;
    A north-south (V) velocity stated in centimeters per second or 
knots; and
    Latitude and longitude of the origin of the U and V velocity 
components.

[Possible sources of information are: the National Ocean Service, U.S. 
Department of Commerce, Riverdale, MD (310) 436-6990; and the Eldridge 
Tide and Pilot Book, Robert Eldridge White Publisher, Boston, MA (617) 
742-3045.]

                                  Tides

    Hour of high tide on the day that the identified substance entered a 
coastal or marine environment;
    Tidal range at point that the identified substance entered a coastal 
or marine environment stated in meters; and
    Whether the tide in the area affected by the release is diurnal 
(i.e., completes one full cycle every day) or semi-diurnal (i.e., 
completes two full cycles every day).

            Modifications to the NRDAM/CME Databases (if Any)

    Documentation of the source of the modification; and
    For air temperature:
    Air temperature, stated in degrees Celsius, assigned by the NRDAM/
CME at the point that the identified substance entered a coastal or 
marine environment (see Table III.3.2, Volume III of the NRDAM/CME 
technical document); and
    Substitute air temperature stated in degrees Celsius.
    For water temperature at the surface:
    Water temperature at the surface, stated in degrees Celsius, 
assigned by the NRDAM/CME at the point that the identified substance 
entered a coastal or marine environment (see Table III.3.3, Volume III 
of the NRDAM/CME technical document); and
    Substitute water temperature stated in degrees Celsius.
    For total suspended sediment concentration:
    Total suspended sediment concentration, stated in milligrams per 
liter, assigned by the NRDAM/CME at the point that the identified 
substance entered a coastal or marine environment (see Section 3, Volume 
I of the NRDAM/CME technical document); and
    Substitute suspended sediment concentration stated in milligrams per 
liter.
    For mean settling velocity of suspended solids:
    Mean settling velocity of suspended sediments, stated in meters per 
day, assigned by the NRDAM/CME at the point that the identified 
substance entered a coastal or marine environment (see Section 3, Volume 
I of the NRDAM/CME technical document); and
    Substitute suspended sediment concentration stated in milligrams per 
liter.
    For habitat type:
    Latitude and longitude bounds of area for which the habitat type is 
being modified;
    Habitat type assigned by the NRDAM/CME (see Section 3.4, Volume III 
of the NRDAM/CME technical document); and
    Substitute habitat type.
    For releases in Alaska, if the authorized official leaves the ice 
modeling function off, he or she must provide documentation that ice was 
absent at the site of the release.

                               Definitions

    Background (mean) current--net long-term current flow (i.e., one 
direction only), attributable to forces such as winds, river flow, water 
density, and tides, that remains when all the oscillatory (tidal) 
components have been removed either mathematically or by measurement 
techniques.
    Landward open water--a body of water that does not contain 
vegetation (e.g., wetland, seagrass, or kelp) or invertebrate reef 
(e.g., coral reef) and is classified as ``landward'' in

[[Page 280]]

Table 6.2, Volume I of the NRDAM/CME technical document.
    Province--one of the geographic areas delineated in Table 6.1, 
Volume I of the NRDAM/CME technical document.
    Seaward open water--a body of water that does not contain vegetation 
(e.g., wetlands, seagrass, or kelp) or invertebrate reef (e.g., coral 
reef) and is classified as ``seaward'' in Table 6.2, Volume I of the 
NRDAM/CME technical document.
    Structured-- in an area that contains vegetation (e.g., wetlands, 
seagrass, or kelp) or invertebrate reef (e.g., coral reef).
    Tidal current--currents caused by alternating rise and fall of the 
sea level due to the gravitational forces between the earth, moon, and 
sun.
    Tidal range--difference between the highest and lowest height of the 
tide.

[61 FR 20612, May 7, 1996]

Appendix III to Part 11--Format for Data Inputs and Modifications to the 
                                NRDAM/GLE

    This appendix specifies the format for data inputs and modifications 
to the NRDAM/GLE under Sec. 11.41. Consult the back of this appendix for 
definitions.

                            Point of Analysis

    The NRDAM/GLE begins its calculations at the point that the released 
substance entered water in an area represented by its geographic 
database. Any water within the geographic boundaries of the NRDAM/GLE is 
a ``Great Lakes environment.'' The authorized official must determine 
all data inputs and modifications as of the time and location that the 
released substance entered a Great Lakes environment. In the case of a 
release that began in water in an area within the boundaries of the 
NRDAM/GLE, this point will be the same as the point of the release. 
However, for releases that begin on land or that begin outside the 
boundaries of the NRDAM/GLE, this point will not be the point of the 
release but rather the point at which the released substance migrates 
into a Great Lakes environment.

                          Required Data Inputs

    Documentation of source of data inputs; and

                          Identity of Substance

    For release of single substance:
    Name of the released substance that entered a Great Lakes 
environment as it appears in Table 7.1, Volume I of the NRDAM/GLE 
technical document (incorporated by reference, see Sec. 11.18).
    For releases of two or more substances or a release of a mixture of 
two or more substances:
    Name of only one of the released substances that entered a Great 
Lakes environment as it appears in Table 7.1, Volume I of the NRDAM/GLE 
technical document.

                             Mass or Volume

    For releases of single substance:
    Mass or volume of identified substance that entered a Great Lakes 
environment stated in tonnes, barrels, gallons, liters, pounds, or 
kilograms.
    For releases of two or more substances or a release of a mixture of 
two or more substances:
    Mass or volume of the one identified substance (rather than total 
mass) that entered a Great Lakes environment stated in tonnes, barrels, 
gallons, liters, pounds, or kilograms.

                                Duration

    Length of time over which the identified substance entered a Great 
Lakes environment stated in hours.

                                  Time

    Year, month, day, and hour when the identified substance first 
entered a Great Lakes environment.

                                Location

    Latitude and longitude, stated in degrees and decimal minutes, where 
the identified substance entered a Great Lakes environment.

                                  Winds

    At least one set of data on prevailing wind conditions for each day 
of the 30-day period beginning 24 hours before the identified substance 
entered a Great Lakes environment. Each set must include:
    Wind velocity stated in knots or meters per second; and 
Corresponding wind direction stated in the degree angle of the wind's 
origin.

[One possible source of information is the National Climatic Data 
Center, Asheville, NC (703) 271-4800.]

                            Response Actions

    Percentage of identified substance removed from water surface, 
bottom sediments, and shoreline; and
    For each medium cleaned (water surface, bottom sediments, or 
shoreline), the number of days after the identified substance entered a 
Great Lakes environment that removal began and ended.

                                Closures

    Documentation that the closure was ordered by an appropriate agency 
as a result of the release; and
    For boating areas:

[[Page 281]]

    Number of weekend days of closure stated by calendar month;
    Number of weekday days of closure stated by calendar month; and
    Area closed stated in square kilometers.
    For beaches:
    Whether the beach was Federal or State (including municipal or 
county);
    Number of days of closure stated by calendar month; and
    Length of shoreline closed stated in meters.
    For fisheries:
    Whether area closed was an offshore, nearshore, or wetland fishery;
    Number of days of closure; and
    Area closed stated in square kilometers.
    For furbearer hunting or trapping areas and waterfowl hunting areas:
    Number of days of closure; and
    Area closed stated in square kilometers.

                         Implicit Price Deflator

    Quarterly implicit price deflator for the Gross National Product 
(base year 1992) for the quarter in which the identified substance 
entered a Great Lakes environment. [See the Survey of Current Business, 
published by the U.S. Department of Commerce/Bureau of Economic 
Analysis, 1441 L Street, NW, Washington, D.C., 20230, (202) 606-9900.]

            Modifications to the NRDAM/GLE Databases (if Any)

    Documentation of the source of the modifications; and
    For air temperature:
    Air temperature, stated in degrees Celsius, assigned by the NRDAM/
GLE at the point that the identified substance entered a Great Lakes 
environment (see Table III.6.1, Volume III of the NRDAM/GLE technical 
document); and
    Substitute air temperature stated in degrees Celsius.
    For water temperature at the surface:
    Water temperature at the surface, stated in degrees Celsius, 
assigned by the NRDAM/GLE at the point that the identified substance 
entered a Great Lakes environment (see Table III.6.2.6, Volume III of 
the NRDAM/GLE technical document); and
    Substitute water temperature stated in degrees Celsius.
    For total suspended sediment concentration:
    Total suspended sediment concentration, stated in milligrams per 
liter, assigned by the NRDAM/GLE at the point that the identified 
substance entered a Great Lakes environment (see Section 3, Volume I of 
the NRDAM/GLE technical document); and
    Substitute suspended sediment concentration stated in milligrams per 
liter.
    For mean settling velocity of suspended solids:
    Mean settling velocity of suspended sediments, stated in meters per 
day, assigned by the NRDAM/GLE at the point that the identified 
substance entered a Great Lakes environment (see Section 3, Volume I of 
the NRDAM/GLE technical document); and
    Substitute suspended sediment concentration stated in milligrams per 
liter.
    For habitat type:
    Latitude and longitude bounds of area for which the habitat type is 
being modified;
    Habitat type assigned by the NRDAM/GLE (see Section 6.2, Volume III 
of the NRDAM/GLE technical document); and
    Substitute habitat type.
    If the authorized official turns off the ice modeling function, then 
he or she must provide documentation that ice was absent from the site 
of the release.

                               Definitions

    Nearshore fishery--fishery in an open water area that is less than 
30 feet in depth or is in a connecting channel.
    Offshore fishery--fishery in an open water area that is 30 feet or 
more in depth.
    Wetland fishery--fishery that is not in an open water area.

[61 FR 20614, May 7, 1996]