(a) Disposition of recoveries. (1) All sums (damage claim and assessment costs) recovered pursuant to section 107(f) of CERCLA or sections 311(f)(4) and (5) of the CWA by the Federal government acting as trustee shall be retained by the trustee, without further appropriation, in a separate account in the U.S. Treasury.

(2) All sums (damage claim and assessment costs) recovered pursuant to section 107(f) of CERCLA, or sections 311(f)(4) and (5) of the CWA by a State government acting as trustee shall either:

(i) Be placed in a separate account in the State treasury; or

(ii) Be placed by the responsible party or parties in an interest bearing account payable in trust to the State agency acting as trustee.

(3) All sums (damage claim and assessment costs) recovered pursuant to section 107(f) of CERCLA or sections 311(f)(4) and (5) of the CWA by an Indian tribe shall either:

(i) Be placed in an account in the tribal treasury; or

(ii) Be placed by the responsible party or parties in an interest bearing account payable in trust to the Indian tribe.

(b) Adjustments. (1) In establishing the account pursuant to paragraph (a) of this section, the calculation of the expected present value of the damage amount should be adjusted, as appropriate, whenever monies are to be placed in a non-interest bearing account. This adjustment should correct for the anticipated effects of inflation over the time estimated to complete expenditures for the restoration, rehabilitation, replacement, and/or acquisition of equivalent resources.

(2) In order to make the adjustment in paragraph (b)(1) of this section, the authorized official should adjust the damage amount by the rate payable on notes or bonds issued by the United States Treasury with a maturity date

(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 §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 § 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 §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,

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 EXPO-
SURE DURING THE PREASSESSMENT
SCREEN

This appendix provides methods for estimating, as required in §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.

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 500foot 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.

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(W;)/(T0.7 Q)

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

W; 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)/V,

where T and L are defined as above and

V, 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 V,=0.38(Q0.40)(S0.20),

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 W;/(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 C, 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: Lim=(1.7×10-5)V, B2(D15 S0.5)

where

Lm is the initial mixing distance, in miles,
V, 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=CV.(Vw+V)

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

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 § 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);

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 southernmost latitude, and the eastern- and westernmost 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:

a

Air temperature, stated in degrees Celsius, assigned by the NRDAM/CME at the point that the identified substance entered 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