20560 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

DEPARTMENT OF THE INTERIOR

Office of the Secretary

43 CFR Part 11

RIN 1090–AA21 & 1090–AA23

Natural Resource Damage

Assessments—Type A Procedures

AGENCY: Department of the Interior.

ACTION: Final rule.

SUMMARY: This final rule amends the

regulations for assessing natural

resource damages under the

Comprehensive Environmental

Response, Compensation, and Liability

Act. Federal, State, and Indian tribe

natural resource trustees may use these

regulations to obtain compensation from

potentially responsible parties for

natural resource injuries resulting from

hazardous substance releases. Trustees

obtain a rebuttable presumption in

litigation for damages, up to $100,000,

calculated in accordance with this rule.

The rule does not change the overall

administrative process for conducting

assessments but simply revises an

existing ‘‘type A’’ procedure for

assessing natural resource damages in

coastal and marine environments and

establishes a new type A procedure for

the Great Lakes.

EFFECTIVE DATE: The effective date of

this final rule is June 6, 1996. The

incorporation by reference of certain

documents listed in this rule was

approved by the Director of the Federal

Register and is effective June 6, 1996.

FOR FURTHER INFORMATION CONTACT:

Mary Morton at (202) 208–3302 (for

questions about the rule language) or

David Rosenberger at (202) 208–3811

(for questions about the computer

models). Interested parties may obtain

copies of the computer models and

supporting documentation free of charge

from the Department through July 31,

1996, and thereafter for a fee from the

National Technical Information Service,

5285 Port Royal Road, Springfield, VA

22161, ph: (703) 487–4650. The models

are also on the Internet at http://

www.usgs.gov/doi/oepc/

oepchome.html.

SUPPLEMENTARY INFORMATION: This

preamble is organized as follows:

I. Background

A. Statutory Provisions

B. History of this Rulemaking

C. Oil Pollution Act Regulations

II. Relationship of Today’s Final Rule to the

Existing Regulations

A. Preassessment Phase

B. Assessment Plan Phase

C. Assessment Phase

D. Post-Assessment Phase

III. Nature of Type A Procedures

IV. Workings of the NRDAM/CME and

NRDAM/GLE

A. Overview

B. Data Inputs and Modifications

C. Geographic Information System

D. Submodels

V. Use of the NRDAM/CME and NRDAM/

GLE in Other Contexts

VI. Summary of Major Changes from the

Proposed Rules

A. Rule Language

B. NRDAM/CME and NRDAM/GLE

VII. Response to Comments

A. General Comments

B. Technical Documents

C. Selection of Assessment Procedures

D. User-Supplied Information

E. Physical Fates

F. Species Distribution and Abundance

G. Toxicity and Mortality

H. Loss of Production

I. Catch and Bag Losses

J. Habitat Restoration

K. Assimilative Capacity Restoration

L. Restocking

M. Consideration of Costs and Benefits of

Active Restoration

N. Damages for Fishing and Hunting Losses

O. Damages for Lost Wildlife Viewing

P. Damages for Beach and Boating Closures

Q. Judicial Review and the Rebuttable

Presumption

I. Background

A. Statutory Provisions

The Department of the Interior (the

Department) is amending the

regulations for assessing natural

resource damages under the

Comprehensive Environmental

Response, Compensation, and Liability

Act, as amended (42 U.S.C. 9601 et seq.)

(CERCLA). CERCLA provides that

certain categories of persons, known as

potentially responsible parties (PRPs),

are liable for natural resource damages

resulting from a release of a hazardous

substance. CERCLA sec. 107(a). Natural

resource damages are monetary

compensation for injury to, destruction

of, or loss of natural resources. CERCLA

sec. 107(a)(4)(C).

Only those Federal, State, and Indian

tribe officials designated as natural

resource trustees may recover natural

resource damages. CERCLA defines

‘‘State’’ to include:

The District of Columbia, the

Commonwealth of Puerto Rico, Guam,

American Samoa, the United States Virgin

Islands, the Commonwealth of the Northern

Marianas, and any other territory or

possession over which the United States has

jurisdiction. CERCLA sec. 101(27).

Trustees must use all sums they

recover in compensation for natural

resource injuries to restore, rehabilitate,

replace, or acquire the equivalent of the

injured natural resources. CERCLA sec.

107(f)(1). Trustee officials may also

recover the reasonable costs of assessing

natural resource damages. Natural

resource damages are distinct from

response costs. Response costs are the

costs of actions taken under the

National Contingency Plan (40 CFR part

300) to remove threats to human health

and the environment caused by

hazardous substance releases. Today’s

final rule addresses only the assessment

of natural resource damages and is not

intended for use in connection with

response-related activities, such as

setting cleanup priorities.

CERCLA requires the President to

promulgate regulations for the

assessment of natural resource damages

resulting from hazardous substance

releases. CERCLA sec. 301(c). The

President delegated the responsibility

for promulgating these regulations to the

Department. E.O. 12316, as amended by

E.O. 12580. The regulations must

identify the ‘‘best available’’ procedures

for assessing natural resource damages.

CERCLA sec. 301(c)(2). CERCLA

requires that the natural resource

damage assessment regulations include

two types of assessment procedures.

‘‘Type A’’ procedures are ‘‘standard

procedures for simplified assessments

requiring minimal field observation.’’

CERCLA sec. 301(c)(2)(A). ‘‘Type B’’

procedures are ‘‘alternative protocols for

conducting assessments in individual

cases.’’ CERCLA sec. 301(c)(2)(B).

Federal and State trustees who perform

assessments in accordance with these

regulations receive a rebuttable

presumption in court. CERCLA sec.

107(f)(2)(C). The Department must

review the regulations, and revise them

as appropriate, every two years.

CERCLA sec. 301(c)(3).

B. History of this Rulemaking

On March 20, 1987, the Department

published a final rule establishing a

type A procedure for coastal and marine

environments that incorporated a

computer model, known as the Natural

Resource Damage Assessment Model for

Coastal and Marine Environments

(NRDAM/CME). 52 FR 9041. The

Department indicated that it would

consider developing additional type A

procedures as experience was gained

with the type A procedure for coastal

and marine environments. Id. at 9057.

On June 2, 1988, the Department

published an advance notice of

proposed rulemaking soliciting

comment on the development of a type

A procedure for Great Lakes

environments that would incorporate a

computer model called the Natural

Resource Damage Assessment Model for

Great Lakes Environments (NRDAM/

GLE). 53 FR 20143. A few months later,
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20561

the Department published an advance

notice of proposed rulemaking

announcing the commencement of the

statutorily required biennial review of

the type A procedure for coastal and

marine environments. 54 FR 5093 (Feb.

1, 1989).

On July 14, 1989, the U.S. Court of

Appeals for the District of Columbia

Circuit issued two decisions that

affected these two pending type A

rulemakings. The Department had

issued type B procedures on August 1,

1986. 51 FR 27674. State, industry, and

environmental group petitioners

challenged those procedures in State of

Ohio v. United States Department of the

Interior (Ohio v. Interior), 880 F.2d 432

(D.C. Cir. 1989). The court in Ohio v.

Interior upheld various aspects of the

type B procedures but ordered the

Department to revise the type B

procedures to reflect the statutory

preference for using restoration costs as

the measure of natural resource

damages. The court used the term

‘‘restoration costs’’ to encompass the

cost of restoring, rehabilitating,

replacing, and/or acquiring the

equivalent of the injured natural

resources. The court also ordered the

Department to revise the type B

procedures to allow for the recovery of

all reliably calculated values lost to the

public as a result of the injury to natural

resources.

State, industry, and environmental

group petitioners also challenged the

original type A procedure for coastal

and marine environments in State of

Colorado v. United States Department of

the Interior (Colorado v. Interior), 880

F.2d 481 (D.C. Cir. 1989). The court in

Colorado v. Interior upheld the

Department’s sequential approach to

developing type A procedures but urged

the Department to develop additional

type A procedures to address as many

different cases as possible. The court

also remanded the type A procedure for

coastal and marine environments, based

on the reasoning in the Ohio v. Interior

decision, to permit the Department to

allow for the calculation of restoration

costs. The original type A procedure for

coastal and marine environments

calculated damages based solely on

certain lost public uses of the injured

resources.

On September 22, 1989, the

Department published an advance

notice of proposed rulemaking stating

that it would revise the type A

procedure for coastal and marine

environments in compliance with Ohio

v. Interior and Colorado v. Interior

during the ongoing biennial review. 54

FR 39013. The Department also

announced that it would modify the

development of the type A procedure

for Great Lakes environments to

conform with Ohio v. Interior and

Colorado v. Interior. 54 FR 39015 (Sept.

22, 1989).

The Department published a notice of

proposed rulemaking for the type A

procedure for Great Lakes environments

on August 8, 1994. 59 FR 40319. The

August 8, 1994, Federal Register notice

also contained two proposed

amendments to the natural resource

damage assessment regulations that

would affect all type A procedures. The

Department proposed to revise the

conditions under which both type A

and type B procedures could be used in

the same assessment, and to make

explicit the scope of judicial review of

assessments performed using type A

procedures. The Department later

extended the comment period on the

August 8, 1994, proposed rule through

February 6, 1995. 59 FR 54877 (Nov. 2,

1994).

On December 8, 1994, the Department

issued a notice of proposed rulemaking

for the modified type A procedure for

coastal and marine environments. 59 FR

63300. On February 7, 1995, the

Department extended the comment

periods on both the proposed Great

Lakes type A rule and the proposed

coastal and marine type A rule through

July 6, 1995. 60 FR 7155 and 7156. The

Department noted that, in light of the

similarities between the two proposed

rules, it would consider the public

comments on the two rules

concurrently. Id. at 7156 and 7157.

Today’s final rule covers both the type

A procedure for coastal and marine

environments and the type A procedure

for Great Lakes environments.

C. Oil Pollution Act Regulations

Originally, trustees could use the

Department’s regulations to assess

natural resource damages resulting from

either a hazardous substance release

under CERCLA or an oil or hazardous

substance discharge into navigable

waters under the Clean Water Act (33

U.S.C. 1251 et seq.). However, the Oil

Pollution Act of 1990 (OPA) amended

the natural resource damage provisions

of the Clean Water Act. See 33 U.S.C.

1321, 2702(b)(2), and 2706(a). OPA

authorized the National Oceanic and

Atmospheric Administration (NOAA) to

develop new natural resource damage

assessment regulations for assessing

natural resource damages resulting from

discharges, or threats of discharges, of

oil into navigable waters that, once

final, would supersede the provisions of

the Department’s regulations addressing

oil. 33 U.S.C 2706(e)(1) and 2751(b).

NOAA published a final OPA rule on

January 5, 1996. 61 FR 439.

The Department began developing the

type A procedures before the enactment

of OPA and, thus, originally included

both hazardous substances and oil in

the NRDAM/CME and NRDAM/GLE

algorithms and databases. The

Department has worked closely with

NOAA during the development of the

type A procedures. During its

rulemaking, NOAA indicated it would

allow use of the Department’s type A

procedures under the OPA regulations.

See 59 FR 1062, 1124–25 (Jan. 7, 1994);

and 60 FR 39803, 39831 (Aug. 3, 1995).

NOAA’s final rule states that trustees

may use ‘‘[m]odel-based procedures,

including type A procedures identified

in 43 CFR part 11, subpart D,’’ provided

that any such procedure meets the

following conditions:

(1) The procedure must be capable of

providing assessment information of use in

determining the type and scale of restoration

appropriate for a particular injury;

(2) The additional cost of a more complex

procedure must be reasonably related to the

expected increase in the quantity and/or

quality of relevant information provided by

the more complex procedure; and

(3) The procedure must be reliable and

valid for the particular incident. 61 FR at 503

(15 CFR 990.27).

Therefore, the Department has

retained components relating to oil in

the final versions of the NRDAM/CME

and NRDAM/GLE, while recognizing

that these components are without any

direct regulatory effect. The Department

is also providing responses to comments

it received on the oil-related

components of the type A models.

However, the Department wishes to

emphasize that its regulations do not

govern the assessment of natural

resource damages for oil discharges

under OPA. Trustees who wish to use

the type A procedures and obtain a

rebuttable presumption for assessments

of oil discharges must follow the

process established by NOAA’s

regulations.

Further, some of the language in the

CERCLA rule varies from that in the

OPA rule. For example, today’s final

rule incorporates the existing definition

of ‘‘reasonable cost’’ at 43 CFR 11.14,

from which the definition in the OPA

rule differs. See 61 FR at 504 (15 CFR

990.30). Section 11.35(b) of today’s final

rule, which requires trustees to conduct

type B procedures if the PRPs advance

the reasonable costs of using such

procedures, differs from the OPA rule

conditions governing PRP requests for

alternative assessment procedures. See

61 FR at 501 (15 CFR 990.14(b)(6)).

Also, § 11.44(f) of today’s final rule
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provides that if the models calculate

damages in excess of $100,000, then

trustees who wish to obtain a rebuttable

presumption must either: (1) limit the

portion of their claim calculated with

the type A procedure to $100,000; or (2)

compute all damages using type B

procedures. The OPA rule, on the other

hand, contains no dollar cut-off for use

of specific procedures. Because use of

the type A procedures for oil discharges

is governed by the OPA rule, the

Department defers to NOAA on how

such differences are to be resolved when

the NRDAM/CME and NRDAM/GLE are

used for assessments of oil discharges.

II. Relationship of Today’s Final Rule

to the Existing Regulations

The existing regulations establish an

administrative process for conducting

assessments. See 43 CFR part 11. The

administrative process covers all the

steps trustees need to follow if they

wish to obtain a rebuttable presumption

in litigation of their claim. However,

trustees have the authority to settle their

damage claims at any time during the

administrative process and the

Department continues to encourage

trustees and PRPs to pursue settlement.

Furthermore, trustees are not required to

follow the regulations. If, however,

trustees and PRPs fail to reach a

settlement and the case is litigated,

trustees will only obtain a rebuttable

presumption if they performed their

assessment in accordance with the

regulations.

The same general administrative

process applies regardless of whether

type A or type B procedures are used.

The process has four phases:

Preassessment, Assessment Plan,

Assessment, and Post-Assessment.

During the Assessment Phase, trustees

use type A and/or type B procedures to

perform the technical work needed for

the actual determination of damages.

Today’s final rule does not change

this overall administrative process. The

rule simply revises the type A

procedures available for use during the

Assessment Phase and modifies the

standards for using both type A and

type B procedures for the same release.

A. Preassessment Phase

Today’s final rule does not affect the

Preassessment Phase. The

Preassessment Phase consists of the

activities that precede the actual

assessment. For example, upon

detecting or receiving notification of a

release, trustees decide, based on a

number of criteria, whether further

assessment actions are warranted.

Trustees document this decision in the

Preassessment Screen Determination.

For more information on the

Preassessment Phase, see subpart B of

43 CFR part 11.

B. Assessment Plan Phase

If trustees determine that additional

assessment work is warranted, they

begin the Assessment Plan Phase. The

Assessment Plan Phase includes the

preparation of a written Assessment

Plan describing the procedures trustees

intend to use to determine damages. The

trustees must make the draft Assessment

Plan available for public review and

comment.

The regulations provide two types of

assessment procedures: type A and type

B. Type A procedures, such as those

contained in today’s final rule, are

simplified procedures requiring

minimal field observation. Type B

procedures involve more detailed field

studies. The Assessment Plan

documents whether trustees plan to use

a type A procedure, type B procedures,

or both. Today’s final rule revises the

standards that trustees must follow

when selecting assessment procedures .

Section 11.34 of today’s final rule

identifies several conditions that must

be met before trustees can use a type A

procedure and obtain a rebuttable

presumption. If the conditions are not

met, then trustees who elect to follow

the regulations must use type B

procedures to assess all damages. If the

conditions are met, then trustees must

decide whether to use a type A

procedure, type B procedures, or both.

This decision is based on whether the

benefits of the increased accuracy

provided by type B procedures would

offset the anticipated additional cost of

using type B procedures, and whether

the anticipated damages would exceed

the anticipated cost of using type B

procedures.

Trustees may use both type A and

type B procedures for the same release

if: (1) The type B procedures are costeffective and can be performed at a

reasonable cost; (2) the type B

procedures are used only to determine

damages for injuries or economic values

of a type not addressed by the type A

procedure; and (3) there is no double

recovery. Section 11.36 of the final rule

lists the categories of damages that are

included in the type A models and for

which trustees may not conduct

supplemental type B studies. Trustees

must document in the Assessment Plan

how they intend to prevent double

recovery when they use both type A and

type B procedures.

Today’s final rule also maintains the

requirement that trustees use type B

procedures, even if they determine that

use of a type A procedure would be

appropriate, whenever a PRP submits a

written request and justification for use

of type B procedures and advances all

reasonable costs of using type B

procedures within a time frame

acceptable to the trustees.

For more information on the

Assessment Plan Phase, see §§ 11.30

through 11.37 of today’s final rule and

subpart C of 43 CFR part 11.

C. Assessment Phase

During the Assessment Phase, trustees

conduct the work described in the

Assessment Plan. The work consists of

three steps: Injury Determination;

Quantification; and Damage

Determination. In Injury Determination,

trustees determine whether any natural

resources have been injured. If trustees

determine that resources have been

injured, they proceed to Quantification,

in which they quantify the resulting

change in baseline conditions.

‘‘Baseline’’ conditions are the

conditions that would have existed had

the release not occurred. Finally, in

Damage Determination, trustees

calculate the monetary compensation to

be sought as damages for the natural

resource injuries. Damages include two

components: (1) The cost of restoring,

rehabilitating, replacing, and/or

acquiring the equivalent of the injured

natural resources; and (2) the economic

value lost by the public pending

recovery of the resources (compensable

value).

When trustees use type B procedures,

they perform Injury Determination,

Quantification, and Damage

Determination through laboratory and

field studies. The regulations provide a

range of alternative type B scientific and

economic methodologies for conducting

such studies. For more information on

use of type B procedures during the

Assessment Phase, see subpart E of 43

CFR part 11.

When trustees use a type A

procedure, they perform Injury

Determination, Quantification, and

Damage Determination through a

computer model. Today’s type A

procedure for coastal and marine

environments incorporates Version 2.4

of the NRDAM/CME. Today’s type A

procedure for Great Lakes environments

incorporates Version 1.4 of the NRDAM/

GLE.

Trustees must supply a number of

data inputs to operate the NRDAM/CME

and the NRDAM/GLE. The rule also

requires trustees to modify certain data

contained in the models if they have

more reliable information. Section 11.41

and Appendices II and III of the final

rule describe the required data inputs

and modifications. After trustees supply
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20563

the data inputs and modifications, the

models themselves perform the

remaining calculations necessary to

establish if there has been an injury,

quantify the extent of injury, select

appropriate restoration actions, and

value economic losses. With the

availability of these computer models,

trustees will now be able to pursue

compensation for cases in which the

cost of detailed type B studies is

prohibitive.

Trustees may not implement type B

procedures until after the public review

period on the Assessment Plan.

However, today’s final rule provides

that trustees who use a type A

procedure must perform a preliminary

application of the model before issuing

the Assessment Plan and then include

the data inputs and the results of the

preliminary application in the publicly

reviewed Plan. This requirement should

provide PRPs and other members of the

public with a more meaningful

opportunity for comment. Performance

of a preliminary application of the

models will also allow trustees to

determine if type B procedures are

warranted in light of a new cap on the

damages that can be claimed through

use of a type A procedure.

The rule now provides that if the

preliminary application indicates

damages in excess of $100,000, then

trustees who wish to obtain a rebuttable

presumption must decide whether to:

(1) limit the portion of their claim

calculated with the type A procedure to

$100,000; or (2) compute all damages

using type B procedures. The $100,000

limit applies only to damages calculated

by a type A procedure and does not

limit damages calculated through

supplemental type B studies. This dollar

cut-off is based on the fairness of

allowing trustees to receive a rebuttable

presumption for damages calculated by

the NRDAM/CME or NRDAM/GLE

given the current level of experience

with these models. The cut-off is not

based on reliability. The Department

believes the NRDAM/CME and

NRDAM/GLE are capable of generating

reliable damage estimates at levels

above $100,000. Therefore, although

trustees cannot use the models and

obtain a rebuttable presumption above

$100,000, the Department believes the

models are appropriate for use in other

contexts, such as settlement

negotiations and litigation without the

rebuttable presumption.

After the close of the comment period

on the Assessment Plan, trustees must

carefully review and substantively

respond to all comments they receive

and must decide whether to continue

using the type A procedure. If they do

decide to continue using the type A

procedure, they must make any

necessary revisions to the user inputs,

and perform a final application of the

model.

For more information on the

Assessment Phase, see §§ 11.40 through

11.44 of the final rule. For more

information on how the NRDAM/CME

and the NRDAM/GLE perform Injury

Determination, Quantification, and

Damage Determination, see Section IV

of this preamble.

D. Post-Assessment Phase

Once the Assessment Phase is

completed, trustees enter the PostAssessment Phase. Today’s final rule

does not substantively modify the PostAssessment Phase.

During the Post-Assessment Phase,

trustees prepare a Report of Assessment

detailing the results of the Assessment

Phase. When trustees use a type A

procedure, the Report will include the

printed output of the final model

application. If a trustee is aware of

reliable evidence that a private party has

recovered damages for commercial

harvests lost as a result of the release,

the trustee must eliminate from the

claim any damages for such lost

harvests included in the lost economic

rent calculated by the model. If a trustee

is aware of reliable evidence that the

model application covers resources

beyond his or her trustee jurisdiction,

the trustee must either: (1) have the

other trustees who do have jurisdiction

over those resources join in the type A

assessment; or (2) eliminate any

damages for those resources from the

claim.

Trustees present the Report of

Assessment to the PRPs along with a

demand for damages and assessment

costs. If a PRP does not agree to pay

within 60 days, the trustees may file

suit. Federal and State trustees receive

a rebuttable presumption of correctness

if they performed their assessments in

accordance with the Preassessment

Phase, Assessment Plan Phase,

Assessment Phase, and Post-Assessment

Phase requirements set forth in the

regulations. Once a court awards

damages or the trustees and PRPs have

reached a settlement, trustees establish

an account to hold the recovered

damages pending preparation of a

Restoration Plan describing how they

intend to use the funds.

When trustees use a type A

procedure, they are not restricted to

implementing the general restoration

methods used by the model to calculate

the restoration cost component of the

damage claim. Instead, trustees have the

discretion to spend recovered sums on

other actions to restore, rehabilitate,

replace, and/or acquire the equivalent of

the injured resources.

Also, existing 43 CFR 11.93(d), which

was not a subject of this rulemaking,

provides that trustees may apply several

type A recoveries to a single Restoration

Plan, so long as the Plan is intended to

address the same or similar injuries as

those identified in each application of

the type A procedure.

For more information on the PostAssessment Phase, see subpart F of 43

CFR part 11.

III. Nature of Type A Procedures

The Department believes it is

important that trustees, PRPs, and the

public clearly understand what the type

A procedures are, as well as what they

are not, intended to provide. The

NRDAM/CME and the NRDAM/GLE are

sophisticated computer models. These

models incorporate a significant level of

site-specific detail about actual physical

and biological conditions in the

geographic areas they encompass. The

language and legislative history of

CERCLA suggest that Congress

envisioned type A procedures as lookup tables based on dollars per gallon or

unit of affected area. See, e.g., S. Rep.

No. 96–848, 96th Cong. 2d Sess. 86 (July

11, 1980). In requiring the development

of two types of assessment procedures—

one simplified and the other more

complex and site-specific—Congress

made a policy choice that trustees be

provided with a simplified, inexpensive

mechanism for obtaining recoveries in

smaller cases. By envisioning a

mechanism such as a look-up table,

Congress obviously recognized that

trustees who use type A procedures

should not be required to develop—or

be prejudiced for not developing—the

same degree of site-specific accuracy as

might be achieved using more expensive

type B procedures. Nevertheless, in

order to increase accuracy, the

Department has developed computer

models that enable the consideration of

site-specific factors. For example, the

NRDAM/CME and NRDAM/GLE take

into account physical variations among

geographic areas, differences in the

toxicity and physical characteristics of

hazardous substances, seasonal and

temperature effects, and differences in

the biological productivity of the spill

site. The Department believes that when

applied correctly using reliable input

data, the NRDAM/CME and NRDAM/

GLE are powerful, reliable tools for

assessing the injuries and compensable

values they address.

However, as sophisticated and

reliable as they are, the NRDAM/CME

and NRDAM/GLE do not, and were
20564 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

never intended to, constitute automated

type B procedures. The NRDAM/CME

and NRDAM/GLE are, after all, only

models of selected aspects of reality

and, like all models, they are incapable

of precisely capturing reality in every

case. Modeling always necessitates

some simplifying assumptions, and the

modeling of something as complex as

the effects of hazardous substance spills

on natural resources necessitates

numerous simplifying assumptions.

Section 11.34 of the final rule

identifies a number of assumptions the

Department made during the

development of the NRDAM/CME and

NRDAM/GLE. If these assumptions are

not reasonable in a particular case,

trustees may not use the models and

obtain a rebuttable presumption. But

even when these assumptions are

reasonable, the models’ damage

estimates will differ from the damages

that type B procedures would produce.

However, Congress explicitly authorized

the development of simplified type A

procedures that required less field work

than type B procedures and then

explicitly granted a rebuttable

presumption to assessments performed

using these type A procedures just as it

granted a rebuttable presumption to

assessments performed using type B

procedures. Finally, the Department has

retained in today’s final rule the safety

valve that always allows PRPs to require

trustees to use type B procedures rather

than a type A procedure if they advance

all reasonable costs of using such type

B procedures within an acceptable time

frame.

The standard for evaluating the

results of the NRDAM/CME or the

NRDAM/GLE in a particular case is not

whether the model projections conform

precisely to field observations. Rather,

the standard is whether the overall

damage figure calculated by the models

is fair and reasonable in light of the

feasibility and cost of developing more

specific information using type B

procedures. For example, if a spill

occurs in an area where biological

conditions are relatively uniform over a

wide area, the fact that the NRDAM/

CME or NRDAM/GLE project that the

surface trajectory would turn to the right

when in fact it turned to the left is not

necessarily adequate grounds to reject

wholesale the results of the model.

IV. Workings of the NRDAM/CME and

NRDAM/GLE

A. Overview

The NRDAM/CME and the NRDAM/

GLE consist of integrated submodels

and databases that calculate natural

resource damages based on certain types

of estimated restoration costs and

compensable values. The NRDAM/CME

and the NRDAM/GLE are complex

computer models; however, their use is

not restricted to computer specialists.

The NRDAM/CME was developed

under contract to the Department by

Applied Science Associates, Inc., A.T.

Kearney, Inc., and Hagler Bailly

Consulting, Inc. The NRDAM/GLE was

developed under contract to the

Department by Applied Science

Associates, Inc., and Hagler Bailly

Consulting, Inc.

‘‘CERCLA Type A Natural Resource

Damage Assessment Model for Coastal

and Marine Environments Technical

Documentation,’’ dated April 1996 (the

NRDAM/CME technical document)

describes the NRDAM/CME. Volume I

of the NRDAM/CME technical

document discusses the content and

derivation of the NRDAM/CME

submodels and databases. Volume II is

a user’s manual. Volume III is a

compilation of the chemical and

environmental databases used by the

NRDAM/CME. Volume IV contains the

biological databases on the species life

histories, species abundances, and

trophic-level production rates used by

the NRDAM/CME. Volume V is a

compilation of the compensable values

and restoration costs used by the

NRDAM/CME. Volume VI is a listing of

the active source code for the NRDAM/

CME.

‘‘CERCLA Type A Natural Resource

Damage Assessment Model for Great

Lakes Environments Technical

Documentation,’’ dated April 1996 (the

NRDAM/GLE technical document)

describes the NRDAM/GLE. Volume I of

the NRDAM/GLE technical document

discusses the content and derivation of

the NRDAM/GLE submodels and

databases. Volume II is a user’s manual.

Volume III is a compilation of all the

databases used by the NRDAM/GLE.

Volume IV is a listing of the active

source code for the NRDAM/GLE.

Today’s final rule incorporates by

reference the NRDAM/CME, the

NRDAM/CME technical document, the

NRDAM/GLE, and the NRDAM/GLE

technical document. Anyone can obtain

computer diskettes containing the

models and technical documents from

the National Technical Information

Service for a fee. The technical

documents supplied on diskette are

formatted in WordPerfect 5.1. Some

databases are formatted in QuatroPro.

Hard-bound copies of the technical

documents are also available. Also, to

facilitate prompt distribution of the

models, the Department will be

providing diskettes of the models and

technical documents free of charge until

July 31, 1996.

The models have a menu-driven

graphic display to assist users. The

minimum computer configuration

required to use the models is:

• IBM-compatible personal

computer (PC) using MS–DOS 3.3 or

higher;

• 80386 processor or better with math

co-processor;

• 1.4 megabyte 3.5 inch floppy disk

drive;

• 4 megabytes of RAM with 540

kilobytes available;

• Hard disk with 75 megabytes of

available space;

• VGA monitor; and

• Microsoft-compatible mouse and

mouse driver software. For further

information on installation of the

models, see Section 2, Volume II of the

NRDAM/CME and NRDAM/GLE

technical documents.

B. Data Inputs and Modifications

The models’ databases include most

of the data used by the models to

determine injury and damages.

However, the final rule requires trustees

to provide certain data inputs. The rule

also requires trustees to modify certain

data contained in the models if they

have more reliable information. The

required data inputs and modifications

are described in § 11.41 and Appendices

II and III.

Trustees may have direct knowledge

of some of the required data inputs.

Additional information may be available

from the On-Scene Coordinator (OSC),

who is responsible for managing

response actions following a release.

The U.S. Coast Guard will normally be

the OSC for releases in coastal or marine

environments or the Great Lakes.

However, trustees remain responsible

for ensuring that all data inputs are

reliable.

C. Geographic Information System

The models incorporate a geographic

information system (GIS) that supplies

geographically distributed information

to the submodels. The submodels divide

space into series of rectangular grids. In

the NRDAM/CME, each grid contains

10,000 cells (100 × 100). In the NRDAM/

GLE, each grid contains 2,500 cells (50

× 50). The size of a specific grid and,

therefore, the interior cells, varies based

on the physical geometry of and the

availability of natural resource

information about the particular

geographic area. For example, the GIS

uses smaller grids for nearshore areas

than for offshore areas. The models

assign a habitat type to each grid cell.

The GIS draws the necessary
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20565

environmental and biotic data from the

appropriate databases. The models

assume that conditions are uniform

throughout a particular grid cell.

For further information about the GIS

and grid system, see Section 2, Volume

I of the NRDAM/CME technical

document; and Section 3.15, Volume I

of the NRDAM/GLE technical

document.

D. Submodels

Both models include four linked

submodels: a physical fates submodel, a

biological effects submodel, a

restoration submodel, and a

compensable value submodel. The

NRDAM/GLE also has a hydrodynamics

submodel.

1. Physical Fates Submodel

The physical fates submodel estimates

the distribution of the released

substance on the water surface, along

shorelines, in the water column, and in

sediments over time. The submodel uses

an array of computational ‘‘particles’’ to

represent the released substance. A

variable fraction of the released

substance is associated with each

particle. The submodel tracks the

distribution of the particles in both time

and space as they move across a threedimensional gridded environment.

Modeled wind and current effects

drive the movement of the particles on

the water surface and in the water

column. In the NRDAM/GLE, the

hydrodynamics submodel simulates the

wind-driven currents occurring in the

water column. In the NRDAM/CME, the

physical fates submodel simulates

wind-driven currents in the upper water

column and employs user-supplied data

inputs on background and tidal currents

to simulate movement in the upper and

lower water column.

Drawing data about the physical and

chemical properties of the released

substance from the chemical and

toxicological database, the submodel

continues simulating the transport and

fate of the substance until all

environmental exposure levels are

below a specified concentration (the

acute toxicity threshold). The acute

toxicity threshold serves as a switch to

turn off the physical fates submodel and

activate the biological effects submodel.

The submodel creates a time-series file

of surface slick coverage, shoreline

coverage, and substance concentration

levels in the water column and in

bottom sediments that is used by the

biological effects submodel.

For further information on the

physical fates submodel, see Section 3,

Volume I of the NRDAM/CME and

NRDAM/GLE technical documents. For

further information on the chemical and

toxicological database, see Section 7,

Volume I, and Section 2, Volume III of

the NRDAM/CME and NRDAM/GLE

technical documents.

2. Biological Effects Submodel

The biological effects submodel

determines whether certain types of

natural resource injuries have resulted

from the release and, if so, quantifies

those injuries. The biological effects

submodel determines and quantifies the

following types of injury: (1) Direct

mortality resulting from short-term

exposure to the released substance; (2)

direct loss of production resulting from

short-term exposure to the released

substance; (3) indirect mortality

resulting from food web losses; and (4)

indirect loss of production resulting

from food web losses. The biological

database supplies data on habitat type

and species biomass to the biological

effects submodel.

The biological effects submodel

determines direct mortality of fish,

shellfish, and wildlife and direct loss of

production for plants and invertebrates

by calculating exposure of different

species to the released substance. When

performing these calculations, the

biological effects submodel uses the

time series data generated by the

physical fates submodel concerning the

distribution and concentration of the

released substance.

The biological effects submodel

determines direct mortality of fish and

shellfish through use of an array of

computational ‘‘particles’’ that move

through the gridded environment. Each

particle represents a portion of the fish

or shellfish populations potentially

exposed to the release. Each time a

particle enters an area with dissolved

water or sediment concentrations of the

spilled substance, the submodel

calculates the percentage mortality of

the fish or shellfish population

represented by the particle. These

calculations continue until

concentrations of the released substance

fall below acute toxicity thresholds.

The biological effects submodel uses

similar procedures to determine direct

mortality of birds and mammals.

However, the submodel only determines

direct mortality of birds and mammals

when the released substance forms a

surface slick.

The biological effects submodel

determines direct mortality of fish and

shellfish eggs and larvae through use of

particle arrays that move with the

currents, as biologically appropriate. For

plants and invertebrates, the submodel

determines direct loss of production

based on the assumption that such biota

are uniformly distributed throughout a

particular habitat type within the model

grids rather than through use of particle

arrays.

Once the biological effects submodel

determines direct mortality and direct

loss of production , the submodel then

calculates indirect mortality and

indirect loss of production for fish,

shellfish, and wildlife resulting from

reductions in food resources. The

submodel uses a generalized food web

model to determine the effect that direct

loss of plant production, invertebrates,

and noncommercial fish and mammals

have on higher trophic-level fish,

shellfish, and wildlife.

After determining injuries from both

direct exposure and food web losses, the

biological effects submodel quantifies

those injuries both in terms of lost

populations over time and, in the case

of fish, shellfish, and wildlife, fishing

and hunting losses. The submodel also

computes fishing and hunting losses

resulting from closures. The

compensable value submodel uses this

information to determine compensable

value.

For further information on the

biological effects submodel, see Section

4, Volume I of the NRDAM/CME and

NRDAM/GLE technical documents. For

further information on the biological

database, see Section 6, Volume I, and

Volume IV of the NRDAM/CME

technical document; and Section 8,

Volume I, and Section 3, Volume III of

the NRDAM/GLE technical document.

3. Restoration Submodel

The restoration submodel estimates

the cost, if any, of restoring the injured

resources. The submodel first evaluates

possible habitat restoration and

restocking actions. The submodel

analyzes the costs and benefits of any

possible habitat restoration and

restocking actions to determine whether

these forms of active restoration or

natural recovery should be assumed for

purposes of the models’ damage

calculations. In some cases, the

submodel also determines the cost of

restoring lost assimilative capacity. The

active restoration costs, if any,

computed by the restoration submodel

comprise one component of the damage

figure; the other component,

compensable value, is calculated by the

compensable value submodel.

For certain types of habitats, the

restoration submodel evaluates habitat

restoration action. The submodel

identifies those habitats for which

human intervention may potentially

facilitate recovery. For each such habitat

in each affected area, the restoration

submodel evaluates the effect that a
20566 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

particular active restoration alternative

would have on the compensable value

calculated by the model. If the relevant

active habitat restoration alternative

would result in a lower total

compensable value for a particular grid

cell than reliance upon natural recovery,

then the restoration submodel computes

the cost of performing that alternative

for that grid cell. The restoration cost

database supplies information on unit

restoration costs to the restoration

submodel. The biological effects and

compensable value submodels supply

information to the restoration submodel

concerning the extent of injury and

compensable value with and without

active habitat restoration. If the active

habitat restoration alternative would not

result in a lower total compensable

value than reliance upon natural

recovery, then the restoration submodel

does not compute any habitat

restoration costs.

The restoration submodel evaluates

the following types of active habitat

restoration alternatives against natural

recovery:

For open water sediments: dredging and

refilling with clean material (shallow water);

or capping (deep water);

For wetlands, macroalgal beds, and

seagrass beds: replacement of contaminated

substrate and replanting (if sediments are

toxic); or replanting (if sediments are not

toxic but mortality has occurred);

For invertebrate reefs (coral and mollusk):

replacement of contaminated substrate and

reseeding (if sediments are toxic); or

reseeding (if sediments are not toxic but

mortality has occurred); and

For shorelines in coastal or marine

environments: washing of sand and gravel;

replacement of mud; and chemical washing

of rocky shoreline.

The restoration submodel then

considers restocking of fish and

wildlife. If stocks of the same age as the

injured fish and wildlife are available

through captive breeding programs, then

the submodel computes the cost of

restocking those species after the habitat

has recovered, either through natural

recovery or active habitat restoration.

The restoration cost submodel supplies

data on the availability and cost of

stocks to the restoration submodel.

If the relevant active habitat

restoration alternative would reduce

compensable value or if restocking is

possible, then the submodel performs a

cost-benefit test of these forms of active

restoration. The submodel compares the

total costs of active habitat restoration

and restocking against the measured

benefits of such restoration (i.e.,

compensable value assuming natural

recovery minus compensable value

assuming active habitat restoration and

restocking). If the costs exceed ten times

the measured benefits, then the

submodel assumes, for purposes of

generating a damage figure, that natural

recovery, rather than active restoration,

will be used to reestablish baseline

conditions. If the costs do not exceed

the measured benefits by ten times, then

the submodel assumes, for purposes of

generating a damage figure, that habitat

restoration and restocking actions will

be implemented.

Finally, for releases that generate a

damage figure related to mortality and

loss of productivity, the restoration

submodel also calculates the cost of

restoring the water’s baseline ability to

absorb pollutants (assimilative

capacity). In the case of such releases,

the restoration submodel determines the

amount of the released substance that

would remain in the environment after

environmental exposure levels are

below acute toxicity thresholds and

after any habitat restoration actions are

completed. The submodel then

computes the cost of removing a

contaminant mass with toxicity

equivalent to the remaining non-acutely

toxic dispersed mass of the released

substance from other identified

contaminated sites. When determining

the amount of contaminant mass to

remove, the submodel adjusts for the

relative degradability of that

contaminant compared to that of the

spilled substance. The restoration cost

database supplies data on unit costs to

the restoration submodel.

The restoration submodel sums the

costs of any selected types of active

restoration. The models combine this

figure with the compensable value

figure computed by the compensable

value submodel to form the final

damage figure.

For further information on the

restoration submodel, see Section 5,

Volume I of the NRDAM/CME and

NRDAM/GLE technical documents. For

further information on the restoration

cost database, see Sections 5, 12, and 13,

Volume I, and Sections 5 through 7,

Volume V of the NRDAM/CME

technical document; and Section 9,

Volume I and Section 5, Volume III of

the NRDAM/GLE technical document.

4. Compensable Value Submodel

Compensable value, as computed by

the compensable value submodel, is the

sum of certain economic use values lost

to the public pending the

reestablishment of baseline conditions

through either natural recovery or active

restoration, as determined by the

restoration submodel. Only public

losses are included in compensable

value.

The submodel computes the following

types of compensable values:

Lost economic rent for lost commercial

harvests resulting from any closures specified

by the authorized official and/or from

population losses;

Lost recreational harvests resulting from

any closures specified by the trustee and/or

from population losses;

In the NRDAM/CME, lost wildlife viewing,

resulting from population losses, by residents

of the States bordering the provinces in

which the population losses occurred;

In the NRDAM/GLE, lost wildlife viewing,

resulting from population losses, by residents

of local areas bordering the provinces in

which the population losses occurred; Lost

beach visitation due to closure; and

In the NRDAM/GLE, lost boating due to

closure.

The submodel calculates compensable

value for lost economic rent by

multiplying the total lost harvest of the

species, as computed by the biological

effects submodel, by the commercial

price per unit of harvest, as supplied by

the compensable value database. The

rule provides that if a trustee is aware

of reliable evidence that a private party

has recovered damages for commercial

harvests lost as a result of the release,

the trustee must eliminate from the

claim any damages for such lost

harvests included in the lost economic

rent calculated by the model.

The submodel calculates compensable

value for lost recreational harvests by

multiplying the total lost recreational

harvest of the species, as computed by

the biological effects submodel, by the

marginal value of harvesting an

additional animal, as supplied by the

compensable value database. The

submodel computes damages only for

harvests lost due to populations losses

or closures. The submodel does not

compute damages for lost quality of

recreational fishing unrelated to lost

harvests or for lost trips due to de facto

closures.

The compensable value submodel

computes compensable value for a

specific range of lost wildlife viewing.

First, the submodel only calculates

wildlife viewing damages resulting from

population losses and does not address

damages resulting from closures.

Second, the submodel only calculates

losses incurred by certain segments of

the wildlife viewing public. The models

divide geographic areas into provinces.

The NRDAM/CME computes lost

wildlife viewing only for residents of

States bordering the provinces in which

the population loss occurred. The

NRDAM/GLE computes lost wildlife

viewing only for residents of local areas

bordering the provinces in which the

population loss occurred. The submodel

calculates damages by multiplying the
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20567

number of viewing trips affected by the

release by the per-animal marginal

viewing value for the animals killed.

The compensable value submodel

computes compensable value for lost

beach visitation only if trustees specify

that there has been a closure of a beach.

The submodel does not calculate

damages for lost quality of beach

visitation or for lost beach visitation due

to de facto closures. If a closure is

specified, the compensable value

submodel calculates compensable value

by multiplying the length of beach

closed per day and the number of days

closed, as supplied by trustees, by the

per-day value of trips to the closed

length. The compensable value database

supplies data on the per-unit value of

lost beach visitation.

The NRDAM/GLE computes

compensable value for lost boating only

if trustees specify that there has been a

closure of a boating area. The model

does not calculate damages for lost

quality of boating or for lost boating

trips due to de facto closures. If a

closure is specified, the compensable

value submodel calculates compensable

value by multiplying the geographic

area closed per day and the number of

days closed, as supplied by trustees, by

the per-day value of trips to the closed

area. The compensable value database

supplies data on the per-unit value of

lost boating. The NRDAM/CME does not

compute compensable value for lost

boating.

The per-unit values in the

compensable value database are stated

in 1991 dollars for the NRDAM/CME

and 1990 dollars for the NRDAM/GLE.

The compensable value submodel uses

the Gross National Product Implicit

Price Deflator, as supplied by trustees,

to adjust per-unit values to current

dollars. The compensable value

submodel discounts the value of future

losses using a three percent discount

rate.

After applying the Gross National

Product Implicit Price Deflator and the

discount rate, the compensable value

submodel sums the lost values to

calculate a compensable value figure.

This figure is added to the restoration

costs, if any, computed by the

restoration submodel to form the final

damage figure calculated by the models.

The rule provides that if a trustee is

aware of reliable evidence that the

model application covers resources

beyond his or her jurisdiction, the

trustee must either: (1) Have the other

trustees who do have jurisdiction over

those resources join in the type A

assessment; or (2) eliminate any

damages for those resources from the

claim. Further, the rule provides that if

the model output indicates damages in

excess of $100,000, then trustees who

wish to obtain a rebuttable presumption

must either: (1) Limit the portion of

their claim calculated with the type A

procedure to $100,000; or (2) compute

all damages using type B procedures.

For further information on the

compensable value submodel, see

Sections 8 through 11, Volume I of the

NRDAM/CME technical document; and

Section 6, Volume I of the NRDAM/GLE

technical document. For further

information on the compensable value

database, see Sections 8 through 11,

Volume I, and Sections 1 through 4,

Volume V of the NRDAM/CME

technical document; and Section 6,

Volume I, and Section 4, Volume III of

the NRDAM/GLE technical document.

V. Use of the NRDAM/CME and

NRDAM/GLE in Other Contexts

The Department is issuing today’s

final rule in compliance with the

statutory requirement to develop

procedures for conducting simplified

assessments that are entitled to a

rebuttable presumption. The standards

in today’s final rule apply only when

trustees use the type A models to

develop a damage figure and intend to

obtain a rebuttable presumption for that

figure in litigation. Trustees who use the

models in other contexts, such as

settlement negotiations or litigation

without the benefit of the rebuttable

presumption, are not subject to the rule

standards. In these other contexts,

trustees are free to make modifications

to the model databases beyond those

permitted under the rule and to use

some, but not all, of the components of

the models.

For example, trustees may wish to use

the models to develop a benchmark

damage figure for settlement

negotiations but may have more up-todate or more site-specific information

on recreational fishing values. In that

case, trustees may choose to apply the

models using modified recreational

fishing values, notwithstanding the rule

provisions concerning modification of

the model databases. In other situations,

trustees may choose to rely on the

models’ predictions of injury but

perform their own analyses of

restoration alternatives and

compensable values. Trustees may also

choose to rely on the models’ damage

calculations for some resources but for

other resources substitute their own

damage calculations for other resources

covered by the models. The Department

believes that although use of the type A

models in these ways would not be

covered by today’s rule and, therefore,

would not be entitled to a rebuttable

presumption, such use can produce

reliable damage estimates if done

properly.

VI. Summary of Major Changes from

the Proposed Rules

The Department has made numerous

changes in the rule language and models

based on the comments received. The

Department discusses its rationale for

these changes in Section VII of this

preamble.

A. Rule Language

The Department has made several

major substantive changes to the

proposed rule language. With regard to

the applicability of the type A

procedures, the Department has

modified the conditions that must be

met before a trustee can use a type A

procedure to obtain a rebuttable

presumption and has eliminated the

provision that would have required

trustees to use the type A procedures in

some circumstances. Instead of

delineating ‘‘primary’’ and ‘‘secondary’’

conditions for use as the proposed rule

did, the final rule now provides that if

the conditions for use of the models

listed in § 11.34 are met, then trustees

decide whether to use type A or type B

procedures based on an evaluation of

the averaged data and simplifying

assumptions listed in the NRDAM/CME

and NRDAM/GLE technical documents.

The Department has also more clearly

delineated the conditions under which

trustees can use type B procedures to

supplement a type A procedure and the

process for doing so.

With regard to operation of the

NRDAM/CME and the NRDAM/GLE,

the rule now allows trustees to modify

the habitat designations in the models

and still obtain a rebuttable

presumption. The rule also requires

trustees to perform a preliminary

application of the NRDAM/CME or

NRDAM/GLE and make the results

available for public review before

performing a final application and

presenting a demand to the PRP.

The final rule contains three new

provisions that require trustees in some

cases to adjust the damage figure

calculated by the models before

presenting a demand. First, the rule now

provides that if trustees are presented

with evidence that private parties have

obtained recoveries for lost commercial

harvests, they must eliminate any

damages for such lost harvests included

in the lost economic rent calculated by

the model. Second, the rule provides

that if a trustee is aware of reliable

evidence that the model application

covers resources beyond his or her

trustee jurisdiction, the trustee must
20568 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

either: (1) Have the other trustees who

do have jurisdiction over those

resources join in the type A assessment;

or (2) eliminate any damages for those

resources from the type A damage

calculation. Third, the rule provides

that if the model output indicates

damages in excess of $100,000, then

trustees who wish to obtain a rebuttable

presumption must either: (1) Limit the

portion of their claim calculated with

the type A procedure to $100,000; or (2)

compute all damages using type B

procedures.

The Department has also eliminated

the proposed clarification of the scope

of review of a type A assessment in a

natural resource damage case.

Finally, as part of its regulatory

reform efforts, the Department has

rewritten the final rule in plain English.

The Department believes this revision

has made the rule significantly clearer

and easier to read.

The following is a section-by-section

analysis of the final rule:

Subpart A—Introduction

Section 11.15 What Damages May a

Trustee Recover?

The Department has rewritten the

heading of this section to make it easier

to understand. The final rule language

revising subsection (a)(1) is unchanged

from the August 1994 proposed rule.

The final rule eliminates the separate

subsections referring to type A

procedures, type B procedures, or a

combination of type A and B procedures

in the same assessment. Sections 11.34

through 11.36 include the criteria and

standards for selecting type A

procedures, type B procedures, or a

combination, making additional detail

in this introductory section

unnecessary.

Section 11.18 Incorporation by

Reference

The final rule slightly revises and

updates the proposed rule language

incorporating by reference the NRDAM/

CME technical document, and adding

language incorporating by reference the

NRDAM/GLE technical document.

Section 11.19 Information Collection

The final rule retains the December

1994 proposed rule language to remove

and reserve this section.

Subpart C—Assessment Plan Phase

Section 11.30 What Does the

Authorized Official do if an Assessment

is Warranted?

The final rule makes several revisions

to this section that were not included in

the proposed rules, but which are

necessary to conform to other provisions

in today’s final rule. Existing subsection

(a), which applied to both type A and

type B procedures, did not authorize

performance of any assessment

methodologies until after the period of

public review and comment for the

Assessment Plan. Section 11.42 of

today’s final rule requires trustees to

perform a preliminary application of the

NRDAM/CME or NRDAM/GLE before

releasing the Assessment Plan for public

review and comment. Trustees who use

type B procedures, however, must still

make the Assessment Plan available for

public review and comment before

performing any of the procedures

contained in the Plan. See § 11.32(c) of

today’s final rule. The Department has

revised the heading of the section and

the language of subsection (a) to make

them easier to understand and to make

this conforming change. The

Department has also modified

subsection (c)(1)(vi) to make a necessary

conforming change cross-referencing

other rule provisions.

Section 11.31 What Does the

Assessment Plan Include?

The final rule revises the heading and

rule language to make the section easier

to understand. Subsection (a)(1) adopts

as final the language in the August 1994

proposed rule.

The Department has revised

subsection (b) from the August 1994

proposed rule to make it clear that the

Assessment Plan must include a

detailed explanation of how the

trustee’s decision to use a type A

procedure, type B procedures, or a

combination, satisfies the decisional

standards contained in the rule.

Subsection (c) clarifies and corrects

existing rule language, which was

garbled in 1988. Compare 53 FR 5174

(Feb. 22, 1988) with 51 FR at 27731.

Although this language was not in the

proposed rules, it is a nonsubstantive

change. Subsection (c)(1) has been

modified to make a necessary

conforming change cross-referencing

redesignated § 11.37.

Subsection (d) revises the existing

rule language to make it easier to

understand. Subpart D contains the

requirements concerning identification

and documentation of information, and

therefore it is unnecessary to repeat

them in subsection (d).

Section 11.32 How Does the

Authorized Official Develop the

Assessment Plan?

The Department has revised the

heading of this section to make it easier

to understand.

The final rule revises subsection (c) to

make it easier to understand and to

make the same necessary conforming

change described in the discussion of

§ 11.30.

The final rule language revising

subsection (f) is slightly reworded, but

substantively the same as, the language

in the August 1994 proposed rule. As

explained in the August 1994 notice of

proposed rulemaking, this provision

clarifies that the confirmation of

exposure requirement applies to type B,

but not type A, procedures. Original

§§ 11.34(a)(1), 11.31(c)(1), and

11.33(b)(4) already established this

distinction. Today’s final rule language

merely makes the rule easier to

understand.

Section 11.33 What Types of

Assessment Procedures Are Available?

Today’s final rule revises § 11.33 to

limit this section to providing a brief

description of the difference between

type A and type B procedures.

Section 11.34 When May the

Authorized Official Use a Type A

Procedure?

New § 11.34 combines and revises

changes that were proposed for § 11.33

in the August 1994 and December 1994

proposed rules. This section now states

the threshold conditions that must be

present before a trustee may use a type

A procedure, many of which were

included among the ‘‘primary’’

conditions in the proposed rules.

Section 11.35 How Does the

Authorized Official Decide Whether to

Use Type A or Type B Procedures?

New § 11.35 further revises changes

that were proposed for § 11.33. The

section provides decisional criteria for

the determination whether to use type A

or type B procedures, assuming that the

conditions in § 11.34 are met. The final

rule language requires trustees to base

the decision whether to use type A or

type B procedures on an evaluation of

the data and assumptions in the type A

procedures, as described in the

NRDAM/CME and NRDAM/GLE

technical documents. These

assumptions include many of the

‘‘secondary conditions’’ contained in

the proposed rules.

Section 11.36 May the Authorized

Official Use Both Type A and Type B

Procedures for the Same Release?

New § 11.36 provides standards for

when trustees may use both a type A

procedures and type B procedures for

the same release. The August and

December 1994 proposed revisions to

§ 11.33 included similar modifications.
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20569

Today’s final rule language provides

clearer, more specific criteria, and

specifically identifies the categories of

injury and compensable value

addressed by the type A procedures.

Subsection (d) addresses the issue of

which type B procedures must be

followed when a trustee decides to

combine a type A and type B procedures

in a single assessment.

Section 11.37 Must the Authorized

Official Confirm Exposure Before

Implementing the Assessment Plan?

The Department has revised the

heading of this section (formerly

§ 11.34) and has modified subsection (a)

from the proposed rule to make it easier

to read. Subsection (a) clarifies the

intent of the existing rule that the

confirmation of exposure requirement

applies only to type B procedures.

Although former § 11.34(a) did not

expressly distinguish between type B

and type A procedures, former

§§ 11.31(c)(1) and 11.33(b)(4) limited

the confirmation of exposure

requirement to type B procedures.

Subpart D—Type A Procedures

Section 11.40 What Are Type A

Procedures?

The Department has revised the

heading of this section and the language

of subsection (a) to make them easier to

read, to add references to the type A

procedures for Great Lakes

environments, to provide additional

information about both type A

procedures, and to incorporate the

requirement that a trustee must follow

the procedures in §§ 11.41 through

11.44 when using either of the two type

A procedures. Today’s final rule

provides a more detailed description of

type A procedures than was contained

in the August 1994 proposed revision to

§ 11.40.

Section 11.41 What Data Must the

Authorized Official Supply?

This section identifies the data inputs

and modifications that the trustee must

supply to use the NRDAM/CME or

NRDAM/GLE. Today’s final rule

modifies and simplifies proposed

§ 11.42 (c) and (d) in the August 1994

proposed rule, and proposed revisions

to § 11.41 in the December 1994

proposed rule. The final rule language

for § 11.41 is considerably shorter than

that in the proposed rules, because the

format for data inputs and modifications

is now contained in two new

appendices to the rule. The final rule

now requires trustees to make certain

modifications to the model databases,

including the habitat designations, if

they have reliable evidence that the

databases are incorrect.

Section 11.42 How Does the

Authorized Official Apply the NRDAM/

CME and NRDAM/GLE?

This section contains a new

procedure requiring trustees to perform

a preliminary application of the

NRDAM/CME or NRDAM/GLE as part

of the process for deciding whether to

use a type A procedure. If the trustee

decides to continue with a type A

procedure, then the data inputs,

modifications, and results of the

preliminary application become part of

the Assessment Plan.

Section 11.43 Can Interested Parties

Review the Results of the Preliminary

Application?

This section requires trustees who

decide to continue with a type A

procedure to develop an Assessment

Plan, which must include the data

inputs, modifications, and results of the

preliminary application. The trustee

must make the Assessment Plan

available for public review and

comment.

Section 11.44 What Does the

Authorized Official do After the Close of

the Comment Period?

Subsections (a) through (c) of this

section state the procedural and

substantive requirements following

public comment on the Assessment

Plan, which include performing a final

application of the NRDAM/CME or

NRDAM/GLE and preparing a Report of

Assessment. Subsection (d) includes

specific criteria to preclude double

recovery for economic rent for lost

commercial harvests if a private party

has already recovered for the same

damages. Subsection (e) resolves a

potential problem arising when trustees

have not agreed in advance to use a type

A procedure jointly. Subsection (f)

limits the damages that may be

recovered by trustees who use the

NRDAM/CME or NRDAM/GLE and

intend to obtain a rebuttable

presumption.

Subpart E—Type B Procedures

Section 11.73 Quantification PhaseResource Recoverability Analysis

The Department has revised

subsection (a) to make a necessary

conforming change to cross-reference

redesignated § 11.35 (now § 11.38).

Subpart F—Post-Assessment Phase

Section 11.90 What Documentation

Must the Authorized Official Prepare

After Completing the Assessment?

The Department has revised the final

rule from the August 1994 proposed

rule to make the heading and rule

language simpler and easier to

understand. The substantive effect of

this provision is the same as existing

§ 11.90.

Section 11.91 How Does the

Authorized Official Seek Recovery of the

Assessed Damages From the Potentially

Responsible Party?

Today’s final rule revises the heading

of the section and the first sentence of

subsection (a) to make the rule language

simpler and easier to understand. The

substantive effect of this provision is the

same as existing § 11.91.

Appendices

The Department has added two new

appendices to the rule. These

appendices specify the format for data

inputs and modifications for the

NRDAM/CME and NRDAM/GLE.

B. NRDAM/CME and NRDAM/GLE

The Department has made several

major substantive changes to the

NRDAM/CME and NRDAM/GLE

computer code and databases. The

Department has revised the chemical

database for both the NRDAM/CME and

NRDAM/GLE to incorporate an

additional 24 oils and petroleum

products. The Environment Canada

publication, ‘‘A Catalogue of Crude Oil

and Oil Product Properties,’’ and

NOAA’s ADIOS (Automated Data

Inquiry for Oil Spills) database provided

the principal sources of information for

revision of the databases. The

Department also deleted the following

hazardous substances from the database:

pure metals, nontoxic substances, and

substances for which the toxicity

threshold was less than the water

solubility. The Department deleted a

total of 31 hazardous substances from

the NRDAM/CME database and 32

hazardous substances from the NRDAM/

GLE database.

The Department has included an

additive toxicity model for oil and

petroleum products in the biological

effects submodel to address the additive

toxicity of the multiple substances in oil

and petroleum products. The additive

toxicity model also addresses the effects

of oil weathering.

The Department has updated the

wildlife viewing values contained in

both the NRDAM/CME and NRDAM/

GLE economic databases based on
20570 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

recent information available from the

1994 addendum to the 1991 National

Survey of Fishing, Hunting, and

Wildlife-Associated Recreation

developed by the U.S. Fish and Wildlife

Service (FWS). Also, in the NRDAM/

CME, the Department revised the

wildlife viewing values to reflect the

total population of the respective coastal

states.

In the NRDAM/CME, the Department

has modified the habitat grids to

provide a finer scale resolution. The

Department changed the scale from a 50

x 50 grid to a 100 x 100 grid. The

Department has also upgraded the

Microsoft compiler to allow for use of

32-bit processing and additional random

access memory (RAM).

The Department has revised the east

coast wetland habitats represented in

the NRDAM/CME grids for provinces

11, 12, and 13 (New York and New

Jersey) to incorporate more site-specific

data provided by commenters. See

Section 3.4, Volume III of the NRDAM/

CME technical document.

In the NRDAM/CME, the Department

has substantially revised wildlife

abundance data for provinces 40

through 51 (west coast and the Gulf of

Alaska) based on additional information

and data provided by public

commenters.

The Department has added a habitat

editor to the NRDAM/GLE user interface

consistent with that provided in the

proposed NRDAM/CME.

The Department has included

intertidal seagrass as an additional

habitat type in the NRDAM/CME. The

intertidal seagrass habitat includes those

common habitats for tropical seagrass

and eelgrass.

The Department has disaggregated the

model output files for the injury and

damage calculations resulting from

direct kills versus food web and habitat

losses, and from commercial versus

recreational fishing losses.

The Department has revised the active

habitat restoration alternatives

evaluated for structured habitats (i.e.,

wetlands, seagrass beds, macroalgal

beds, and invertebrate reefs) to include

not only sediment replacement with

replanting but also replanting alone.

The Department has eliminated the

calculation of compensable value for

lost boating and subsistence losses from

the NRDAM/CME.

The Department has revised the

restoration submodel to include a costbenefit test for determining whether the

measured benefits of active habitat

restoration and restocking, as compared

to natural recovery, are worth the

additional costs.

Finally, the Department has revised

the calculation of assimilative capacity

restoration costs to correct for the

degradation rate of the spilled substance

and to limit the calculation of

assimilative capacity restoration costs to

cases where biological injury has

occurred and produces compensable

value.

VII. Response to Comments

The Department received numerous

public comments on the proposed type

A procedures. The Department and

NOAA also asked several independent

technical reviewers to examine the

proposed NRDAM/CME. The

Department made the comments of

these independent technical reviewers

available to the public and included

them in the administrative record for

this rulemaking. See 60 FR 28773 (June

2, 1995). The Department provides

responses to both the public comments

and the comments of the independent

technical reviewers below.

In addition to the issues discussed

below, commenters addressed a number

of issues beyond the scope of this

rulemaking. The Department explicitly

limited this rulemaking to four issues:

the revision of the existing type A

procedure for coastal and marine

environments; the development of a

new type A procedure for Great Lakes

environments; the conditions for

combined use of type A and type B

procedures; and the scope of judicial

review of assessments performed using

type A procedures. See 59 FR at 40319–

20, 63300, and 63302. Nevertheless,

some commenters raised additional

issues, including: whether trustees

should be allowed to pool natural

resource damage recoveries to

implement regional restoration plans;

the permissibility of using type A and

type B procedures for the same release;

and whether lost economic rent and the

cost of restoring lost assimilative

capacity are legally permissible

categories of damages. The Department

has not evaluated, and is not providing

substantive responses to, comments on

these issues in this rulemaking.

Section 11.93(d) of the existing

regulations, which was promulgated in

1987, allows pooling of multiple type A

recoveries to implement a single

restoration plan, so long as the plan is

intended to address the same or similar

injuries as those identified in each

application of the type A procedure. See

52 FR at 9100. The Department neither

reproposed, revisited, nor solicited

comment on § 11.93(d) and merely cited

it in the preambles to the proposed rules

by way of background. 59 FR at 40324

and 63305.

Section 11.15(a)(1)(iii) of the original

type A rule, which was promulgated in

1987, established that trustees could use

both type A and type B procedures for

the same release under certain

circumstances. See 52 FR at 9095. The

Department did not repropose, revisit,

or solicit comment on whether CERCLA

allows trustees to combine type A and

type B procedures. The only issue raised

and addressed in this rulemaking was

whether the Department should expand

the authorization for combined use of

type A and type B procedures.

Finally, the Department did not

repropose, revisit, or solicit comment on

its long-standing positions on the

recoverability of damages for lost

economic rent and lost assimilative

capacity. Both the original type B rule

and the original type A rule explicitly

allowed for the recovery of lost

economic rent. See 43 CFR 11.83(c)(1);

51 FR at 27749; and 52 FR at 9047. The

Department has recognized the loss of

assimilative capacity as a legitimate

category of natural resource damages

since the promulgation of the original

type B procedures in 1986. 51 FR at

27716; see also 59 FR at 14273. The

Department has begun a biennial review

of the type B procedures and will be

considering the issues of lost economic

rent and lost assimilative capacity in

that context. See 59 FR 62749 (Oct. 19,

1994).

A. General Comments

Comment: Some commenters

supported the concept of a reliable,

accurate, automated damage assessment

procedure that would eliminate the

need for expensive tailor-made studies.

However, other commenters objected to

the calculation of damages through what

they considered to be abstract

application of theoretical, generic

models. Some of these commenters

thought that many of the calculations of

the NRDAM/CME and NRDAM/GLE

were based on unsubstantiated

assumptions.

A number of commenters, including

some of the independent technical

reviewers, questioned the Department’s

use of ‘‘grand averages’’ to extrapolate

data for a specific species, substance, or

location, to different species,

substances, and locations. Commenters

were particularly concerned about the

extrapolation of economic values made

in the compensable value submodel. For

example, commenters noted that some

of the studies used to value recreational

fishing in the NRDAM/CME were based

on freshwater fishing and commercial

fishing. Commenters also stated that

many of the studies used outdated data

and outdated or unreliable
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20571

methodologies. For example,

commenters noted that recreational

hunting values were derived from a 20-

year old contingent valuation study.

Some commenters suggested specific

criteria that they thought should be met

when performing benefits transfer (i.e.,

the extrapolation of economic values

derived from studies of one situation to

another situation).

Response: CERCLA requires that type

A procedures involve ‘‘minimal field

observation’’ and authorizes type A

procedures to be based on ‘‘units of

discharge or units of affected area.’’

CERCLA sec. 301(c)(2)(A). The Senate

Report that accompanied the

predecessor bill to CERCLA provides

the following indication of Congress’

intent:

Natural resource damage assessments

based on this type of regulation [type A]

should require as little fieldwork as possible,

and rely on a combination of habitat values,

tables of values for individual species, and

previously conducted surveys and laboratory

studies, related to units of discharge or units

of affected area. S. Rep. No. 96–848 at 86.

This language indicates that Congress

envisioned the development of type A

procedures that do not require the

performance of any new studies but

instead use existing studies to provide

generalized values that can be applied

in specific cases. Inherent in the

concept of developing unit values from

existing studies is the notion of making

assumptions in the absence of empirical

data and applying average values across

a range of nonidentical items. Therefore,

the Department believes that CERCLA

authorizes it to make appropriate

extrapolations from existing data.

The science of natural resource

damage assessment is still evolving. The

universe of relevant studies is still very

small for many crucial aspects of

damage assessment. Existing data are

particularly limited as to the effects of

small spills. Even when addressing the

limited range of scenarios covered by

the NRDAM/CME and the NRDAM/

GLE, the Department faced significant

challenges in bridging data gaps.

Although Congress did authorize the

Department to make extrapolations from

existing data, the Department recognizes

that any such extrapolations must be

reasonable. Thus, when developing the

models, the Department tried to make

use of the most reliable information

available based on extensive reviews of

published and unpublished information

and data; make only those assumptions

that are necessary; ensure that any

assumptions that are made are

reasonable; and identify clearly all

assumptions that were required for the

development of simplified procedures.

With regard to the compensable value

submodel, the Department did apply

specific criteria during its selection of

studies to use for benefits transfer. The

Department used only studies that: (1)

Were based on an extensive literature

review and consultations with relevant

governmental agencies; (2) reasonably

represented the natural resource and

public use under investigation; (3)

contributed to a reasonable

representation of the different regions

included in the models; (4) were

conducted by a recognized universityassociated researcher or established

consulting firm; and (5) used

appropriate valuation methodologies.

The Department believes that these

criteria adequately address all the

concerns that the commenters’

suggested criteria are intended to

address. The first three criteria assure

that the resources considered in the

selected studies are as similar as

possible to the resources to be valued in

the models. The fourth criterion assures

that the selected studies are

scientifically sound. The fifth criterion

assures that the selected studies use

appropriate valuation methodologies.

Comment: One commenter suggested

that the Department had developed the

models by selecting values from a few

studies while ignoring others. The

commenter argued that the Department

had failed to provide adequate

justification for the values it selected.

Response: The Department conducted

extensive searches for available

information. Some data the Department

identified were not used because better

or more applicable data were available.

However, none of the identified data

was ignored. The Department believes

that the NRDAM/CME and NRDAM/

GLE technical documents adequately

explain and justify the values in the

models.

Comment: Some commenters thought

that the proposed type A models were

so technically flawed that they did not

meet the statutory standard of ‘‘best

available procedures’’ and, therefore,

trustees should not obtain a rebuttable

presumption if they use the models.

These commenters urged the

Department to abandon the models

noting that Colorado v. Interior does not

require or authorize the Department to

issue a model that is unreliable. One

commenter acknowledged that the

proposed revised NRDAM/CME

appeared to be an improvement over the

original NRDAM/CME Version 1.2

issued in 1987. However, the

commenter thought the proposed

revised model still contained too many

flaws to accomplish its intended

purpose. Another commenter stated that

the damage figures produced by the

models are nothing more than sheer

speculation and are not legally

sufficient due to the compounding of

errors, uncertainties, biases, and

overestimates.

Response: As discussed in more detail

below, the Department has carefully

reviewed all comments it received on

the proposed models and rule language.

Based on this review, the Department

has made numerous modifications to

the models and the rule language.

Where the Department concluded that

no changes were needed, the

Department has explained its reasoning.

The Department believes that the final

type A models, as revised in response to

comments, are best available procedures

when used in accordance with the

standards and process set forth in

today’s final rule. The models, with

their state-of-the-art modeling and

extensive databases, represent a

significant advancement beyond the

original NRDAM/CME issued in 1987.

The final type A procedures provide for

reliable, cost-effective, simplified

assessments that are entitled to a

rebuttable presumption.

Comment: Several commenters

thought the Department had been overly

ambitious in attempting to develop

models like the NRDAM/GLE and the

NRDAM/CME. Specifically, these

commenters stated that the biological

effects submodel attempted to perform a

task that is beyond the current state of

ecological modeling. The commenters

contended that state-of-the-art

ecological modeling is not yet capable of

producing accurate quantitative

determinations and is primarily useful

only for making qualitative predictions.

The commenters also thought that the

multiple iterative calculations

performed by the biological effects

submodel did not alleviate the problem

but simply amounted to averaging of

nonsense.

Response: The Department agrees that

ecological models should generally be

used only for qualitative predictions.

However, the biological effects

submodel in the NRDAM/GLE and the

NRDAM/CME is not a true ecological

model in the sense suggested by

commenters. Ecological models evaluate

the changes in ecosystem structure and

function resulting from disturbances.

The biological effects submodel, on the

other hand, is a toxicological effects

model. The biological effects submodel

simply calculates acute mortality and

lost production and projects these

injuries forward as biota not present or

used in future years. The submodel

need not, and does not attempt to,

address the higher-order ecological
20572 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

changes in the structure and functions

of biological systems as true ecological

models do.

The Department believes that the

NRDAM/CME and NRDAM/GLE are

reasonable tools for assessing the

injuries and compensable values that

they address and do not generate

‘‘nonsense.’’ Further, the use of iterative

calculations is designed to, and does,

enhance the reliability of damage

estimates in particular cases. The

biological effects submodel uses several

randomized algorithms for processes,

such as swimming by fish, that are

considered random at the relevant

spatial and temporal scales. For each

spill modeled, the submodel performs

multiple iterative runs and then selects

the mean result. This approach is a

generally accepted method of modeling

the most probable biological effects for

events that have an element of

randomness.

Comment: Some commenters thought

the proposed models were

fundamentally flawed because they

used overly simplistic simulations of

movement of biota within a population.

The commenters stated that these

simulations could not be improved

because of the lack of basic data on

population movement.

Response: The Department believes

that the NRDAM/CME and the NRDAM/

GLE use the best available procedure for

simulating the movement of biota and

that this procedure is reliable for the

purposes of a simplified damage

assessment. The Department

acknowledges that the directed

movement of biota is not well

understood quantitatively. However, at

the smallest scale, there is a random

component to the movements of animals

within the habitats they occupy, and the

NRDAM/CME and NRDAM/GLE can

and do model this component. The

models do not simulate within-season,

between-habitat movements, except

where currents carry organisms across

boundaries. However, the seasonal and

habitat-specific abundances included in

the database do account for inter-habitat

movement between seasons.

Comment: Some commenters,

including some of the independent

technical reviewers, thought that the

Department should validate the models

against real-world data and perform

sensitivity analyses. A few commenters

also thought the Department should

calibrate the models.

Response: The Department has

conducted extensive sensitivity studies

of both the NRDAM/CME and NRDAM/

GLE. It is difficult to conduct conclusive

validation studies of the models due to

the extreme lack of data on the natural

resource effects of small spills. In fact,

although more data exist for large spills,

even those data are limited.

Nonetheless, the Department has used

the data that are available to conduct

validation studies of the NRDAM/CME

physical fates and biological effects

submodels and believes that these

studies suggest that the submodels

provide reasonable estimates of the

actual physical fates and biological

effects of spills. Even less data exist for

spills in the Great Lakes than for spills

in coastal and marine environments.

However, since the NRDAM/GLE

contains the same algorithms as the

NRDAM/CME, the Department believes

the results of the validation studies of

the NRDAM/CME also support the

NRDAM/GLE.

Because of the cost involved in

performing site-specific type B studies,

trustees have rarely pursued damage

claims for minor releases. Therefore,

virtually no data exist with which to

validate the restoration and

compensable value submodels or

determine the need for calibrating the

damage estimates produced by the

models. In the absence of such data, the

Department has relied primarily on

careful reviews of the accuracy and

reasonableness of the data and

algorithms used in the models. The

Department believes that these reviews

of the scientific underpinnings of the

models provide adequate support for the

reliability of the damage estimates

produced by the models.

The Department further believes that

the models are consistent with

congressional intent underlying the

directive to produce procedures for

simplified assessments. The models are

best available simplified procedures.

They produce reliable, fair, and

reasonable results when used for their

intended purpose. The Department has

clearly identified the capabilities and

limitations of the models and has

allowed trustees to select between type

A and type B procedures based on

specified criteria. Finally, the

Department has retained the provision

allowing PRPs to require trustees to use

type B procedures if they advance the

reasonable cost of using such

procedures within an acceptable time

frame.

Comment: One commenter stated that

the NRDAM/GLE should be peer

reviewed in an open forum prior to

promulgation.

Response: The Department believes

that the NRDAM/GLE has been

adequately reviewed. The proposed

model was made available for public

review and comment for eleven months.

Also, the review of the proposed

NRDAM/CME by independent technical

reviewers was directly relevant for the

NRDAM/GLE because the NRDAM/GLE

incorporates the same basic modeling as

the NRDAM/CME.

Comment: Some of the independent

technical reviewers claimed that the

proposed NRDAM/CME underestimated

damages. In support of this claim, these

reviewers noted that when used to

calculate damages for certain actual

releases, the model generated damage

figures that were usually at least an

order of magnitude less than the figure

for which the parties settled.

Response: The Department believes

that when the conditions set forth in

§ 11.34 are met, the models will

generate reasonable and appropriate

damage figures for the injuries and

losses these simplified procedures

address. The Department does not

believe that historical settlements

provide an accurate or meaningful

standard against which to judge the

reliability of damage figures generated

by the NRDAM/GLE and the NRDAM/

CME. Although real-life case data on

physical fates and biological effects can,

in some instances, provide useful

comparisons when evaluating the

physical fates and biological effects

submodels, bottom-line settlement

figures may differ from model damage

figures for a number of reasons that have

nothing to do with reliability.

First, because of the cost involved in

performing site-specific type B studies,

trustees have rarely pursued damage

claims for minor releases. Therefore,

historical natural resource damage

settlements usually involve large spills.

The type A models were designed for

minor releases and are based on various

assumptions that often are not

reasonable in the case of large spills.

Therefore, the restoration and

compensable value submodels would

not have been applicable to the cases in

which natural resource damage

settlements have been reached.

Second, it is difficult to determine the

appropriate user inputs for some of the

actual cases, many of which are several

years old. For example, user-supplied

information on beach, and fisheries

closures can significantly affect the total

damage figure, yet data on the actual

extent of such closures are in some

cases no longer available.

Third, the models do not purport to

capture all, or even most, of the ‘‘real

world’’ or ‘‘actual’’ damages that could

be determined if the costs of a full onsite assessment were not a

consideration. Instead, the models use

averaged values to calculate a specific

subset of the damages resulting from a

release. When used for the minor
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20573

releases for which they are intended, the

models yield reliable and appropriate

damage figures that are calculated at a

reasonable cost. Past natural resource

damage settlement agreements have

generally identified a single damage

figure that is not broken down by

component. In fact, most settlement

agreements to date have not even listed

which types of injuries and losses the

agreement is intended to address.

Therefore, it is usually impossible to

determine if the model is even

calculating the same type of damages as

those covered by the settlement, let

alone whether the calculation produces

a damage figure that matches the

settlement figure. The larger—and more

complicated—the release, the greater the

likelihood of a divergence between the

type A damage figures and the more

site-specific damages that might be

calculated using type B procedures. The

fact that such divergence occurs, and

even at times might appear ‘‘extreme,’’

does not suggest unreliability or an

inappropriate ‘‘underestimation’’ of

damages by the type A models. Rather,

it only serves to illustrate the limited

function these procedures are intended

to serve, and the reason they are

designed to be used for minor releases,

for which the costs of type B procedures

cannot be justified when compared to

the anticipated level of damages.

Finally, settlements are the result of

negotiation. The negotiation process

usually begins before either party has

completed its assessment work.

Settlement negotiations are influenced

by both parties’ perception of several

factors extraneous to the assessment

process. These factors include: the

transaction costs associated with

delaying settlement or terminating

negotiations and litigating the case; the

strength of the liability portion of the

case; the PRP’s financial condition; and

the trustee’s ability to fund a complete

assessment. In light of the influence of

these factors in settlement negotiations

and the other difficulties in comparing

settlement figures against model

calculations, the Department does not

believe that variances between model

damage figures and historical

settlements indicates anything about the

reliability of the models, when used as

intended.

Comment: One of the independent

technical reviewers questioned why the

damages calculated by the proposed

NRDAM/CME do not agree with those

calculated by the original NRDAM/CME

for the same spill.

Response: The new NRDAM/CME

differs significantly from the 1987

version of the model due to

modifications made in compliance with

the Colorado v. Interior remand as well

as modeling and database improvements

made as a result of the biennial review.

Among the most significant differences,

the original model assumed a generic

study area defined by the user with

uniform depth, habitat, and

environmental conditions. Today’s final

NRDAM/CME allows for geographic

resolution of multiple habitats, depths,

coastline, shore type, currents, ice cover

and other environmental condition. The

new NRDAM/CME contains much larger

biological and economic databases,

resolving many more species categories

and geographic regions. Also, the new

NRDAM/CME contains a restoration

submodel and restoration cost database.

The Department believes that these and

other changes have resulted in

significant improvements in the

reliability of the calculations of the

model.

Comment: One commenter stated that

the models were unreliable because

NOAA used them to develop proposed

OPA compensation formulas that

generated unrealistic damage figures.

Response: The Department does not

believe that damage figures produced by

NOAA’s proposed OPA compensation

formulas are relevant to the evaluation

of either the proposed or final versions

of the NRDAM/GLE and NRDAM/CME.

On January 7, 1994, NOAA proposed

compensation formulas for determining

natural resource damages under OPA.

59 FR at 1176–77. These formulas were

based on early developmental drafts of

the NRDAM/GLE and the NRDAM/CME

that the Department made available to

NOAA in 1991. The Department has

extensively modified both the NRDAM/

CME and NRDAM/GLE since 1991. For

example, the Department has revised

the algorithms contained in the physical

fates and biological effects submodels;

expanded and updated the biological

databases; and revised the chemical and

economic databases. Section VI.B of this

preamble identifies other major changes

that the Department made to the

NRDAM/CME and NRDAM/GLE as a

result of public comments.

Comment: One commenter stated that

the proposed NRDAM/CME

dramatically underestimated damages as

compared to the compensation table

developed by the State of Washington

under its natural resource damage laws.

The commenter expressed concern that

PRPs may use the NRDAM/CME to seek

reductions in the State compensation

table.

Response: The Department does not

believe it is appropriate or relevant to

compare the results of type A model

runs against the figures in Washington’s

compensation table, because the type A

models and the State table are based on

different approaches to damage

assessment. The Washington table

establishes a pre-set, per-gallon scale of

damages. The type A models, on the

other hand, estimate the actual effects of

the release and then generate a sitespecific damage figure based on the cost

of restoring injured resources plus

selected public economic values lost

pending recovery.

With regard to PRPs’ potential use of

the type A models to undermine the

Washington table, the Department

would like to emphasize that the type A

models were developed specifically for

use under Federal law. State or tribal

simplified procedures may take into

account costs, economic values, or other

considerations not reflected in the type

A models. As such, the damages

produced by the type A models are not

an appropriate point of comparison for

evaluating State or tribal procedures.

The type A models in no way preempt

State or tribal procedures that are

authorized under and designed to

enforce non-Federal laws.

Comment: Several commenters

questioned the disparity between the

levels of sophistication of different

components of the models. Some of the

independent technical reviewers noted

that the compensable value submodel,

unlike the relatively complex physical

fates and biological effects submodels,

essentially amounted to a look-up table.

These reviewers thought that the

Department should develop a more

dynamic economics model. Other

commenters thought that significant

disparities in complexity existed even

within the physical fates and biological

effects submodels.

Response: The Department has

attempted to incorporate the best

available procedures for modeling all

components of the type A models. The

Department acknowledges that the

levels of intricacy vary throughout the

models. These variances reflect the

differing degrees of current technology

and scientific knowledge. Economic

science has not progressed to the point

where there are general models of

recreational demand that can be readily

applied to specific recreational activities

at specific locations. This is in distinct

contrast to the biological and physical

sciences. The physical fates and

biological effects submodels are based

on parameterizations of known and

generally accepted models of physical

and biological processes.

Comment: One of the independent

technical reviewers stated that the

models incorporate some biases that

will result in underestimates of damages

and other biases that will result in
20574 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

overestimates. The technical reviewer

suggested that the models provide a

range of damage estimates that reflect

consistent use of conservative

assumptions on one end and consistent

use of liberal assumptions at the other

end. Another independent technical

reviewer suggested that the models be

modified to perform an uncertainty

analysis for each run.

Response: The Department believes it

has adequately and appropriately

addressed the potential for bias in the

NRDAM/CME and NRDAM/GLE. The

type A procedures are principally

designed to establish a process for

trustees to follow if they wish to pursue

a natural resource damage claim and

obtain a rebuttable presumption in

court. In a suit for damages, trustees will

need to identify a specific claim.

Therefore, the Department has

developed type A models that generate

a single damage figure rather than a

range of possibilities.

Moreover, where commenters, or the

Department itself, identified specific

potential biases in the proposed models,

the Department modified the models to

correct for such biases to the extent

possible. Where the Department could

not eliminate the potential for bias, it

identified the simplifying assumptions

made in the models that produce that

potential. As discussed further below,

those assumptions that could result in

significant overestimates of damages if

they are not reasonable in a particular

case are listed in § 11.34 as conditions

that must be met if the trustees expect

to obtain a rebuttable presumption.

Those assumptions that are not likely to

result in significant overestimates of

damages if they are not reasonable in a

particular case, and, in fact, may result

in underestimates, are explicitly

identified in Section 1, Volume I of the

NRDAM/CME and NRDAM/GLE

technical documents. Section 11.35(a)

provides that if a type A procedure is

applicable, trustees must determine

whether to use type A or type B

procedures based on an evaluation of

those model assumptions.

As discussed in Section III of this

preamble, the type A models are neither

expected nor intended to produce

damage estimates that ‘‘match’’ the

results of more complex site-specific

assessment procedures. Therefore, the

Department has concluded that a

traditional uncertainty analysis is not

needed.

Comment: Several commenters

thought the scope and complexity of the

proposed NRDAM/GLE and NRDAM/

CME were too great. A few commenters

thought the models were so complex

and difficult to use that operating them

was beyond the ability of untrained

users. One commenter thought the

technical documents should clearly

state the required user qualifications.

Several commenters, including some of

the independent technical reviewers,

suggested improved user interfaces.

Some of the independent technical

reviewers thought that additional user

guidance was needed; one suggested

that the Department develop an

animated tutorial.

Response: While the Department

acknowledges that the NRDAM/CME

and NRDAM/GLE are functionally very

complex, it does not believe that they

require an undue level of expertise to

operate. Users must simply be able to:

(1) Understand the conditions for use in

§ 11.34; (2) evaluate the models’

simplifying assumptions listed in of

Section 1, Volume I the technical

documents; (3) evaluate the averaged

data included in the models as

described in Volumes III through IV of

the NRDAM/CME technical document

and Volume III of the NRDAM/GLE

technical document; and (4) enter

correctly the required user-supplied

data as described in Appendices II and

III of the rule. Users who meet these

standards will obtain reliable results

regardless of whether they have a full

understanding of all the models’

components.

As discussed further below, the

Department has revised the regulatory

conditions for use of the models to

clarify a number of points of confusion.

Section 1, Volume I of the NRDAM/

CME and NRDAM/GLE technical

documents now contains a clearer,

simpler discussion of all the major

model assumptions of which users

should be aware when determining

whether to use type A or type B

procedures. The Department has also

rewritten the regulatory discussion of

the user-supplied information and

moved that discussion into appendices

in an attempt to make it easier to read.

Volume II of the technical documents

includes a revised discussion of how to

develop and input the user-supplied

data. Finally, the models provide a

graphic user interface that has been

revised to further simplify the task of

the user. While additional guidance

might be helpful and may be developed

in the future, the Department believes

that the current level of guidance is

adequate to allow non-expert users to

operate the model correctly.

Comment: Some of the independent

technical reviewers questioned why the

user interface was not consistent with

Windows software.

Response: The Department chose to

develop the user interface as a standalone product that would not require

licensing a copyrighted product such as

Windows software.

Comment: A few commenters

complained about the speed of the

proposed models. Some commenters

called upon the Department to upgrade

the computer platform required to run

the models. The commenters thought

that such an upgrade would enable

users to complete model runs in hours

rather than days and would allow the

models to use more detailed databases,

thus increasing accuracy.

Response: In developing the type A

models, the Department had to strike a

balance between the desire for the speed

afforded by high-powered computer

equipment and the need to ensure that

any type A procedure developed is

readily accessible to a wide array of

potential users. The Department

believes it has struck the appropriate

balance in the PC environment.

It is evident from even a cursory

review of the technical documents that

the models are very complex and

perform millions of individual

calculations during a run. The

Department has made every effort to

optimize the models for speed without

compromising their accuracy or

applicability. Obviously, there continue

to be advances in PC technology. For the

development of the type A models, it

was necessary for the Department to

settle on a widely-available computer

platform and finalize the rule. While

more recent technological developments

will allow these models to run faster on

improved computer platforms, the

Department decided that maintaining

the models for use on 386 PCs would

not compromise their function or

purpose and would keep them readily

accessible to potential users.

Model run times are affected by the

complexity of the spill (e.g., amount

spilled, duration of the spill, and

degradation rate of the spilled

substance) as much as the computer

platform utilized. Nonetheless, for

minor spills, most runs are executed in

a matter of minutes rather than hours or

days even on a 386 PC. The models will

take significantly less time to run on a

486 PC or a Pentium PC, but the user

is not precluded from using an older

model of computer.

Since the issuance of the proposed

rule, the NRDAM/CME has been moved

to a 32-bit FORTRAN compiler. This

move allowed the Department to

subdivide the habitat grids by a factor of

four and increase the number of

computational particles used to

represent spilled material and biota.

These changes should improve the

accuracy of the model. The area
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20575

modeled in the NRDAM/GLE is much

smaller than that modeled in the

NRDAM/CME. Therefore, the

Department concluded that these

changes were not needed in the

NRDAM/GLE to increase speed or

accuracy.

Comment: One of the independent

technical reviewers stated that when he

attempted to replicate test runs on the

proposed NRDAM/CME he obtained

different results.

Response: Users will obtain identical

results if, but only if, they use identical

inputs. The Department designed the

type A models so that they will produce

identical results, regardless of the make

or model of PC used, if the usersupplied inputs are identical. To

accomplish this result, the Department

built a table of random numbers into the

models’ code rather than have the

models use the random number

generating features of the

microprocessor.

Comment: Several commenters,

including some of the independent

technical reviewers, suggested that the

Department include additional

categories of damages in the type A

models. Commenters recommended that

the Department add the following losses

to the models: sublethal biological

effects; chronic biological effects;

wetland losses; nonuse losses (i.e.,

economic values that are not dependent

on use of a resource, such as the value

of knowing a resource exists); de facto

beach, boating, and fisheries closures;

reductions in the quality of boating and

beach recreation in the absence of

closures; reductions in the quality of

recreational fishing unrelated to

mortality or closures; and ecosystem

functional losses such as reductions in

filtration, mineral recycling, and

decomposition. These commenters

expressed concern that if the models are

not expanded to cover additional losses,

then type A assessments will

consistently underestimate damages.

They noted that Ohio v. Interior and

Colorado v. Interior instructed the

Department to allow for the recovery of

all reliably calculated losses.

Commenters also thought that, in light

of the cost of type B procedures, it was

disingenuous of the Department to state

that trustees could simply use type B

procedures to calculate damages for

losses not included in the models.

Response: The Department has

attempted to include in the models all

categories of loss and injury for which

adequate, reliable information exists in

a format that enables the calculation of

damages for the wide range of

substances, resources, and geographic

areas covered by the models. The

Department acknowledges that the type

A models do not address all potential

losses and injuries that might result

from a release and that, in some cases,

losses not included in the models may

be significant. The Department further

acknowledges that Ohio v. Interior and

Colorado v. Interior instructed the

Department to allow for the recovery of

all reliably calculated values. The issue,

then, is reliability. The exclusion of

certain categories of injury and loss

from the models was based on the

Department’s evaluation of whether

there was adequate reliable information

to support their inclusion.

For example, the Department has

considered the comments suggesting the

addition of nonuse losses, but continues

to believe that the addition of such

values is not feasible at this time. As

discussed in the proposed NRDAM/

CME technical document, most studies

of nonuse values do not report marginal

nonuse values that would be required

for the type A models as they are

presently designed. See Section 8.5.2,

Volume I of the proposed NRDAM/CME

technical document. Furthermore, these

studies have tended to focus on the

nonuse values of threatened or

endangered species. As a consequence,

the bulk of available studies are not

directly applicable to the estimation of

nonuse values that would be lost as a

result of the small spills addressed by

the type A models.

Furthermore, the final rule explicitly

provides that where trustees expect

losses that are not addressed by the

models, they may consider using type B

procedures in addition to a type A

procedure, provided that type B

procedures are cost-effective, can be

performed at a reasonable cost, and do

not result in double recovery. The

Department recognizes that type B

procedures are likely to be significantly

more costly than type A procedures and,

in some cases, trustees may not be able

to perform type B procedures and still

satisfy the rule’s reasonable cost

standard. Nevertheless, the Department

does not believe that the cost of

performing type B procedures justifies

the inclusion in the models of losses for

which there is an inadequate basis to

determine damages. During future

biennial reviews, the Department will

reevaluate whether additional

information has become available that

supports expansion of the categories of

losses and injuries included in the

models.

Comment: One of the independent

technical reviewers stated that

additional detail should only be added

to the models if it influences the final

damage figure.

Response: The ultimate purpose of all

the calculations made by the type A

models is the determination of a reliable

damage figure. Therefore, while

reviewing the comments and deciding

which changes to make to the models,

the Department has focused on whether

the suggested changes would

significantly improve the reliability of

the final damage figure.

Comment: One commenter suggested

that trustees be allowed to use

simplified procedures developed by

States and receive a rebuttable

presumption under the CERCLA

regulations. Another commenter

requested that the Department develop

compensation tables for commonly

released hazardous substances.

Response: Some simplified State or

tribal procedures may well be

appropriate for use under CERCLA.

However, only a handful of coastal

States have developed such procedures.

Further, these State procedures have

been developed under State laws, which

may establish somewhat different

objectives and standards than CERCLA.

The Department believes it would need

to evaluate carefully any particular State

or tribal procedure to determine its

consistency with CERCLA’s regulatory

mandate before allowing it to be used

and accorded a rebuttable presumption

under these regulations. Therefore, the

Department decided it was more

appropriate to develop its own

simplified procedures for the coastal

and marine and Great Lakes

environments.

The primary advantage of

compensation tables appears to be their

ease of use. The Department believes

that the NRDAM/CME and NRDAM/

GLE are simple enough to operate that

compensation tables are not necessary.

Further, the Department believes that

the models will provide a level of sitespecific accuracy beyond that which a

compensation table could offer.

Although the Department has decided

not to incorporate compensation tables

or simplified State or tribal procedures

in this rulemaking, the Department has

begun to evaluate the need for, and

feasibility of, additional type A

procedures. See 60 FR 24604 (May 9,

1995). The Department will further

consider the use of simplified State

procedures and the development of

compensation tables in that context.

B. Technical Documents

Comment: Some commenters stated

that the Department had failed to

provide adequate documentation

explaining how the proposed models

operated and why the Department made

the choices it did when developing
20576 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

different components of the proposed

models. One commenter stated that the

scope and complexity of the models

were too great and suggested that a

revised program be developed and

accompanied by a simplified synopsis

of the technical assumptions and

formulas presented in a format more

amenable to comment. Commenters

cited case law requiring agencies to

provide a complete explanation and

defense of models used in the

development of regulations. The

commenters noted that the Department’s

obligation to provide a full discussion of

the type A models was even greater

because the models are used to

determine monetary liability of

particular parties.

Response: The Department

acknowledges its duty to provide an

adequate explanation and justification

of the models and to provide the public

with a meaningful opportunity to

review and comment on the proposed

models. The Department believes it has

fulfilled this duty.

The proposed models were

accompanied by lengthy and detailed

technical documents describing the

content, workings, and development of

the models. The proposed NRDAM/

CME technical document exceeded

2,400 pages in length; the proposed

NRDAM/GLE technical document was

almost 1,500 pages in length. Also, the

preambles to the proposed rules

provided a roadmap to the technical

documents, highlighting areas of

potential concern and identifying where

various issues were discussed in the

technical documents. The Department

made the proposed models and

technical documents available on

diskette free of charge to anyone who

requested them.

To assist commenters in reviewing the

models, the Department equipped the

proposed models with a user interface

that included pull-down menus, ‘‘help’’

screens, and graphic displays of the

physical environments and usergenerated runs of the physical fates

submodel. The Department also

incorporated pertinent calculations from

the physical fates, biological effects,

restoration, and compensable value

submodels into the printed model

output to enable reviewers to evaluate

the reliability of the models for

incident-specific model applications.

The Department notes that the goal of

developing models that calculate

compensatory damages for spills

throughout the Great Lakes and coastal

and marine environments has

necessitated a relatively high level of

complexity in modeling. The

Department recognizes that with models

as complex as the NRDAM/CME and

NRDAM/GLE some reviewers will

always want more information on

specific elements while others will be

overwhelmed as the documentation

becomes more extensive. Although the

Department never deliberately omitted

any discussion it thought would be of

interest to reviewers, the Department

did recognize that providing too much

information can be just as problematic

as providing too little. The Department

has tried to be sensitive to the risk that

important information can become

buried in a mountain of detail.

The Department extended the public

comment period on the proposed

NRDAM/CME once and on the proposed

NRDAM/GLE twice. The total comment

periods were seven months for the

proposed NRDAM/CME and eleven

months for the proposed NRDAM/GLE.

Those reviewers left with questions after

reviewing the models and technical

documents were free to contact

Departmental staff at any time during

the comment period.

Finally, the Department has provided

additional discussion of specific model

aspects in the final versions of the

NRDAM/CME and NRDAM/GLE

technical documents and in this

preamble as a result of specific public

comments.

Comment: Several commenters,

including some of the independent

technical reviewers, said that the

technical documents were either

unclear or difficult to use. Others noted

confusing table captions and headings,

inconsistencies, incorrect citations, and

typographical errors. One commenter

suggested that major assumptions for

each submodel be placed in bold print

at the beginning of each section. One

commenter recommended that the

technical documents be amended to

give examples of when the models

might underestimate or overestimate

damages.

Response: The Department has

reviewed and revised the NRDAM/CME

and NRDAM/GLE technical documents

to further clarify algorithms,

assumptions, and data sources. The

Department has also checked the

documents for consistency, particularly

with regard to terminology and has

fixed the noted typographical errors and

incorrect citations. Section 1, Volume I

of the NRDAM/CME and NRDAM/GLE

technical documents now more clearly

identifies all the major assumptions of

which trustees should be aware when

deciding whether to use the models and

describes the likely results if the

assumptions are not reasonable in a

particular case. Further, the discussion

of each submodel in Volume I of the

technical documents now starts with a

list of the assumptions relevant to that

submodel.

C. Selection of Assessment Procedures

Comment: The Department received

numerous comments on the proposed

conditions for use of the type A models.

The proposed rules identified a set of

primary conditions and a set of

secondary conditions. Under the

proposed rules, if any primary condition

were not met, trustees would not have

been allowed to use the type A

procedure. If all primary and all

secondary conditions were met, trustees

would have been required to use the

type A procedure for all damages. If all

primary conditions but only some

secondary conditions were met, trustees

could have used a combination of type

A and type B procedures.

Some commenters thought the

proposed rules were overly prescriptive

in dictating which type of assessment

procedures trustees may use. These

commenters argued that trustees should

have greater discretion to determine

which procedures, type A, type B, or a

combination, are appropriate in a

particular case. Commenters expressed

concern that the conditions regarding

use of the type A procedures were

vaguely defined and would invite

confrontation and litigation if they were

imposed as requirements. These

commenters supported expansion of the

authority to use type A and type B

procedures in combination, but thought

the proposed rules still did not provide

adequate flexibility. These commenters

also stated that the type A procedures

were particularly useful when used with

selective site-specific studies of impacts

not addressed in the type A models.

Other commenters, including one of

the independent technical reviewers,

thought that the proposed rules gave

trustees too much discretion in selecting

assessment procedures. Some of these

commenters thought that the conditions

regarding use of the type A procedures

should be clearer and stricter. One of

the independent technical reviewers

suggested that the Department

recharacterize the assumptions made by

the models as limits of applicability.

One commenter argued that trustees be

required to use a type A procedure

unless they provide scientific

justification for using type B

procedures. On the other hand, some

commenters expressed concern that the

proposed rules would allow excessive

use of the type A procedures and

suggested making the primary

conditions more restrictive.

Several commenters objected to the

proposed provision allowing combined
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20577

use of type A and type B procedures.

The commenters argued that Congress

intended the type A and type B

procedures to be mutually exclusive.

These commenters also thought that

combined use of type A and type B

procedures would pose significant risks

of double recovery of damages and that

the proposed rules failed to provide any

guidance on how to prevent such

double recovery. One commenter stated

that combined use of type A and type

B procedures was inconsistent with the

‘‘average’’ values justification for

simplified procedures, since type B

procedures would be used to offset type

A underestimates without any

corresponding offset of type A

overestimates. Another commenter

expressed concern that if allowed to

supplement type A assessments,

trustees would spend enormous sums

assessing nonuse values for small

releases even though such releases are

unlikely to produce any meaningful

nonuse losses. Some commenters stated

that if the final rule allowed use of type

B procedures to supplement a type A

assessment, then such use should be

limited to resources not included in the

type A procedure.

Response: The type A models are

powerful tools for completing

assessments and beginning restoration

as quickly and cost-effectively as

possible. The Department has sought to

balance the utility of making these tools

available in the widest possible range of

cases against the potential dangers that

they may produce unreliable results

when stretched beyond their limits or

that they may result in double recovery

when inappropriately combined with

type B procedures.

The Department has carefully

reexamined both the proposed

conditions regarding use of the models

as well as the additional major

simplifying assumptions incorporated

into the models and described in the

technical documents. The Department

has concluded that the conditions for

use of the models should recognize two

different categories of assumptions built

into the models. The first category

encompasses those assumptions that

could result in significant overestimates

of damages if they are not reasonable in

a particular case. The second category

encompasses those assumptions that are

not likely to result in significant

overestimates of damages if they are not

reasonable in a particular case and that

may well result in underestimates.

The Department believes it is

inappropriate to grant a rebuttable

presumption to an assessment

performed using the NRDAM/CME or

NRDAM/GLE if one of the assumptions

in the first category is not reasonable in

the particular case. If an assumption in

the second category is not reasonable in

a particular case, it may be appropriate

for trustees to use type B procedures to

ensure that the public receives full

compensation for its losses. However,

the Department believes trustees in

those cases should have the option of

using the type A models when the costs

of type B procedures are not reasonable.

The appropriateness of the models in

these cases will depend on site-specific

factors. The Department has concluded

that it is more appropriate to allow

trustees to analyze these factors in the

context of a particular case than to

establish inflexible, overly rigid

standards.

Therefore, the Department has

identified all the major model

assumptions and for each one

determined into which of the two

categories they fall. Those assumptions

in the first category are identified in

§ 11.34 of the final rule as conditions

that must be met if trustees intend to

use the NRDAM/CME or NRDAM/GLE

and obtain a rebuttable presumption.

These assumptions include most of the

primary conditions in the proposed

rules.

The Department has identified the

assumptions in the second category and

listed them, along with the other

assumptions, in Section 1, Volume I of

the NRDAM/CME and NRDAM/GLE

technical documents. These

assumptions include many of the

secondary conditions in the proposed

rule. Section 11.35(a) provides that if

the conditions for use of a type A

procedure are met, the trustee must

decide whether to use that procedure or

use type B procedures by weighing the

difficulty of collecting site-specific data

against the suitability of these

additional assumptions as well as of the

averaged data described in Volumes III

through IV of the NRDAM/CME

technical document, and in Volume III

of the NRDAM/GLE technical

document.

The Department has eliminated the

proposed provision that would have

required trustees to use a type A

procedure in some cases. That

requirement was originally motivated

out of concern over potential misuse of

unnecessarily expensive and timeconsuming type B procedures. 59 FR at

40322. Although the models are costeffective, reliable tools where

applicable, the Department has

concluded that trustees should not be

prevented from conducting site-specific

work if they can do so at a reasonable

cost and if the additional costs of

performing type B procedures are

warranted in light of the degree of

additional precision and accuracy that

such procedures will provide.

The issue of the legal permissibility of

allowing trustees to use both type A and

type B procedures for the same release

is one that the Department decided and

resolved in 1987 and is beyond the

scope of this rulemaking. Today’s final

rule merely expands the use of

supplemental type B studies beyond

resources not addressed by the type A

procedure to include compensable

values and injuries of a type not

addressed by the type A procedure.

The Department acknowledges that

combined use of type A and type B

procedures can, in some instances, pose

potential double counting problems.

However, trustees should not be forced

to choose between forgoing

compensation for a public loss not

addressed by the type A model on the

one hand and funding a full-scale, timeconsuming, labor-intensive type B

assessment of all injuries on the other

hand. Instead, the potential problems

with combined use of type A and type

B procedures should be addressed

through limitations designed to protect

against double recovery.

The final rule provides that trustees

who use a type A procedure may

perform additional type B studies only

for injuries or compensable values of a

type not addressed by the type A

procedure. The secondary conditions in

the proposed rules have been recast to

identify explicitly the injuries and

compensable values that are addressed

in the type A models and, therefore,

may not be supplemented with type B

procedures.

Given the vast range of potential

scenarios, it is infeasible to develop a

single, uniform formula for preventing

double recovery. Instead, § 11.15(d) of

the existing regulations prohibits double

recovery of damages. Also, § 11.36(a)(2)

of today’s final rule provides that

trustees may only perform supplemental

type B procedures if such procedures

will not result in double recovery.

Further, § 11.36(c) requires trustees to

provide an explanation in the

Assessment Plan of how they intend to

avoid any double recovery in the case of

combined use of type A and type B

procedures. PRPs and the public will

have an opportunity to review the

trustees’ strategy for preventing double

recovery when the Assessment Plan is

made available for public comment.

The Department agrees with the

comment that the type A procedures can

be particularly useful when combined

with selective studies of impacts not

addressed by the models. The

Department would like to ensure that
20578 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

where combined use of type A and type

B procedures is warranted, trustees are

freed from conducting duplicative

assessment procedures. Therefore, the

Department has modified the final rule

to clarify that when using type B

procedures for compensable values that

are not included in a type A procedure,

but that result from injuries addressed

by the type A procedure, trustees need

not conduct injury determination and

quantification all over again using type

B procedures. Instead, trustees may rely

on the injury projections of the type A

model and simply use one of the type

B valuation methodologies authorized

by § 11.83 (a) and (c) to compute

compensable value.

With regard to the concern about

unwarranted type B studies of nonuse

values, aside from the implausibility of

the scenario suggested by the

commenter, the Department notes that

calculation of nonuse values using type

B procedures is under examination in a

separate rulemaking. See 59 FR 23097

(May 4, 1994). Therefore, this

rulemaking need not address this issue.

Finally, the Department believes it is

appropriate to revise the existing rule to

allow supplemental use of type B

procedures beyond resources not

addressed in the type A models. The

public can experience significant and

distinct losses associated with the same

resource. Ohio v. Interior emphasized

that the regulations should allow for the

recovery of all reliably calculated lost

values. 432 F.2d at 464. The Department

sees no reason to impose an arbitrary

distinction between losses associated

with different resources and losses

associated with the same resource so

long as there is no double recovery.

Comment: One commenter suggested

that trustees be allowed to use

supplemental type B procedures to

determine damages for habitats that are

not accurately represented in the

models.

Response: In cases where the models

assign an incorrect habitat designation

for a specific area, trustees have the

ability to correct that designation and

would not need to conduct

supplemental type B studies. In cases

where releases affect habitats beyond

the models’ level of spatial detail,

trustees may perform supplemental type

B studies so long as such studies do not

address injuries or compensable values

in the categories listed in § 11.36(b) of

the final rule. The Department does not

believe it is appropriate to expand this

authority to conduct supplemental type

B studies and still obtain a rebuttable

presumption. When such small habitats

are affected, the models will

nonetheless determine injury and

damages for the geographic area in

which those habitats are located. If a

trustee were to use one of the models

and then conduct supplemental type B

studies of such a habitat, the trustees

would need to adjust the type A damage

figure to eliminate any damages

calculated for the area over which the

habitat is located. The Department has

concluded that in the context of a

simplified assessment, trustees who

wish to obtain a rebuttable presumption

should be limited to conducting type B

studies for the purposes of addressing

additional injuries and compensable

values that are not included in the

model rather than substituting for

damages already calculated by the

model.

Comment: A number of commenters

thought that trustees should be

prohibited from using type A

procedures unless all interested trustees

agree to a single joint assessment. These

commenters stated that such a provision

was necessary to avoid the problems of

double recovery and improper

allocation of damages among trustees.

These commenters thought that these

problems were more significant for type

A assessments than for type B

assessments because the type A models

provide less detail than type B

procedures on the type and location of

injured resources and the damages

associated with those resources.

Response: The Department

acknowledges that the type A models

pose a unique problem when trustees do

not act jointly. The type A models

generate a total damage figure for all

affected resources. Therefore, if a trustee

acts independently and applies a type A

model, the total damage figure generated

by the model might include damages for

resources that are not under that

trustee’s jurisdiction.

To address this problem, § 11.42 now

requires a trustee to perform a

preliminary application of the model

before making the draft Assessment Plan

available for public review and

comment. The trustee must include a

summary of the model application in

the draft Assessment Plan and make

available a copy of the model output.

The output of the model does in fact

identify the type and location of injured

resources. Section 11.31(a)(2) of the

existing regulations requires trustees to

include in the Assessment Plan a

statement of authority for asserting

trusteeship for those resources

addressed in the Plan. Therefore, PRPs

and other interested members of the

public will have an opportunity to

comment on whether any of the injured

resources identified in the model output

are beyond the scope of the trustee’s

jurisdiction.

Also, § 11.44(e) provides that if a

trustee is aware of reliable evidence that

a type A application covers resources

beyond his or her trustee jurisdiction,

the trustee must either: (1) Have the

other trustees who do have jurisdiction

over those resources join in the type A

assessment; or (2) eliminate any

damages for those resources from the

claim for damages.

Furthermore, the Department strongly

encourages trustees to work together to

ensure that natural resource damage

assessments remain focused on restoring

the injured resources rather than

debating over which trustee has

jurisdiction over them. As noted by

some of the commenters, § 11.32(a)(1) of

the existing regulations requires a

trustee to notify all other interested

trustees before beginning an assessment

and encourages all trustees to cooperate

and coordinate. Also, § 11.15(d) of the

existing regulations prohibits double

recovery of damages.

The issue of inter-trustee coordination

extends beyond this rulemaking to the

overall administrative process for

conducting all assessments. The

potential for overlapping claims exists

whenever trustees conduct separate

assessments, regardless of whether type

A or type B procedures are used. The

Department has initiated a biennial

review of the administrative process for

conducting assessments. The

Department will be further examining

the issue of inter-trustee coordination

during that review. 59 FR at 52752.

Comment: A few commenters stated

that PRPs should be ensured a

meaningful opportunity to participate in

the selection of assessment procedures.

These commenters requested that PRPs

be given a chance to review trustees’

assumptions and reasoning.

Commenters also expressed support for

cooperative trustee-PRP assessments.

Response: The Department agrees that

PRPs should have an opportunity to

participate in selection of assessment

procedures. Section 11.32(a)(2)(iii)(A) of

the existing regulations already requires

trustees to invite PRPs to participate in

the development of the type and scope

of the assessment as well as the

performance of the assessment

procedures. Today’s final rule does not

change that requirement. Section

11.32(c) requires trustees to make their

Assessment Plans available for public

review and comment. The proposed rule

required trustees to include in their

Assessment Plans documentation of

their decision whether to use a type A

procedure, type B procedures, or both.

Section 11.31(b) of today’s final rule
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20579

now makes more explicit the trustees’

duty to provide a detailed explanation

of their rationale for using a type A

procedure, type B procedures, or both.

Also, § 11.35(d) now clarifies that

trustees may change their decisions

about the types of procedures they use

based on public comments.

Comment: Many commenters

addressed specific proposed conditions

for use of the models. Some commenters

questioned the condition regarding

whether the data in the models

reasonably represented the spatial and

temporal distribution of affected

biological resources. One commenter

suggested that this condition was

inconsistent with the habitat editor.

Another commenter requested

clarification of the term ‘‘reasonably

represented.’’ This commenter

expressed concern that the condition

seemed to require trustees to collect

baseline data, which would defeat the

intent of requiring minimal field

observation in type A procedures.

Response: The Department has

reexamined this proposed condition

regarding use of the models. The

condition addressed two different

model assumptions. First, the condition

addressed the assumption that the

release did not affect any small but

important environments beyond the

level of spatial detail of the model.

Second, the condition addressed the

assumption that species biomass is

averaged spatially and temporally. The

Department has concluded that if the

first assumption is not reasonable in a

particular case, then the model will

most likely underestimate, rather than

overestimate, damages. Therefore, the

Department has eliminated this

assumption from the conditions for use

listed in § 11.34 of the final rule.

Instead, the Department has identified

the assumption in the NRDAM/CME

and NRDAM/GLE technical documents

as one of the factors for trustees to

consider when deciding whether to use

type A or type B procedures, once they

have established that the conditions set

forth in § 11.34 are met. See Section 1,

Volume I of the NRDAM/CME and

NRDAM/GLE technical documents. The

Department has clarified the second

assumption, concerning species

biomass, and included it in § 11.34 as a

condition that must be met if trustees

intend to use the models and obtain a

rebuttable presumption.

The habitat editor does not conflict

with either of these assumptions. The

final rule allows trustees to change the

habitat designation for an entire existing

grid cell. However, the rule does not

allow trustees to redraw the boundaries

of the grid cells or modify the species

biomass for a particular habitat. Even

with correct habitat designation, edited

or through the built-in designation, the

models may not reflect small habitats or

populations with densities that differ

from the seasonal average.

The Department acknowledges the

confusion generated by the term

‘‘reasonably represented.’’ The term was

not intended to require trustees to

conduct field surveys to collect baseline

data. Instead, it was designed to address

cases where information already existed

about baseline conditions and such preexisting information differed

significantly from the data in the model.

Section 11.34(e) now simply provides

that a trustee may not use the models if

he or she is aware of reliable evidence

that, for species expected to represent a

significant portion of the claim, the

species biomass is significantly lower

than the species biomass assigned by

the models.

Comment: A few commenters noted

that the models may significantly

underestimate damages when the

released substance causes chronic or

sublethal effects, when sensitive

habitats or life stages are affected, when

animals aggregate for feeding or

reproduction, or when long-term effects,

such as reproductive impairment or

changes in food web structure, are

expected.

Response: The Department

acknowledges that the type A models

may not accurately calculate total

damages in the situations identified by

the commenters. However, the

Department has included provisions in

the final rule to address these situations.

Section 11.35(a) provides that if a type

A procedure is applicable, trustees must

determine whether to use type A or type

B procedures based on an evaluation of

the model assumptions listed in Section

1, Volume I of the NRDAM/CME and

NRDAM/GLE technical documents. One

of the listed assumptions is that there

are no affected environments beyond

the spatial detail of the models. This

assumption will alert trustees to the

potential for underestimating damages

where sensitive habitats are affected.

Another listed assumption is that

species biomass is averaged spatially

and temporally. This assumption will

alert trustees to the potential for

underestimating damages when animals

aggregate. Finally, the rule explicitly

identifies the injuries addressed by the

type A models; therefore, trustees will

have notice that they will need to

perform supplemental type B

procedures if they wish to address

chronic or sublethal biological injuries.

Comment: Some commenters thought

that trustees should be allowed to use

the models only if the release is a single

event. These commenters expressed

concern that in the absence of such a

requirement, trustees could use a type A

procedure to assess one release in a

multi-release incident and use type B

procedures to assess the other releases.

The commenters thought that such a

practice would result in double

counting because some of the injuries

predicted for one release would already

be accounted for in the assessment of

another release. These commenters also

thought that the rule should be

rewritten to clarify that the type A

models can be applied only to releases

of a single substance. The commenters

noted that without this change, similar

double counting problems could arise

from multiple applications of the

models.

Response: The Department has

concluded that the model assumption

that the release is a single event need

not be made a condition for use of the

models. Instead, Section 1, Volume I of

the technical documents notes that the

models assume that each spill is an

independent, short-term event.

Section 11.15(d) of the existing

regulations already prohibits double

recovery of damages. In the case of a

multi-release incident, if trustees choose

to use a type A model for one release

and then conduct type B studies for the

other releases, they will be required to

ensure that the type B procedures do not

result in double recovery. The

Department acknowledges that in some

cases it may be difficult for trustees to

satisfy this requirement. However, the

Department believes that in those multirelease cases where trustees can tailor

their type B studies to address only the

effects of the releases not assessed by

the type A model, they should have the

opportunity to do so.

With regard to releases of multiple

substances, the rule now provides that

trustees must select and assess only one

of the substances that was released. See

Appendices II and III. This requirement

will eliminate double counting

problems. In fact, toxicity of mixtures

has been found to be additive or

synergistic in aquatic environments for

a wide variety of substances. See

Section 4, Volume I of the NRDAM/

CME technical document. Thus, this

requirement may actually result in

underestimates of damages. However,

the Department believes that in cases of

mixtures when the cost of using type B

procedures is not reasonable, trustees

should have the option of using a type

A procedure rather than forgoing all

compensation.

Comment: A few commenters

addressed the use of the models for
20580 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

substances not specifically identified in

the database. Some commenters

supported giving trustees flexibility to

use the models for such substances

provided that they identified a proxy

that was included in the database and

documented the reasons why the use of

that proxy was appropriate. Other

commenters expressed concern that

allowing use of proxies would add a

significant range of discretion given the

number of different physical and

chemical attributes that must be

considered when identifying a proxy.

Some commenters, including one of the

independent technical reviewers,

suggested that the Department expand

the oil database.

Response: The Department has

concluded that allowing the use of

proxies for hazardous substances

without significant guidance on

selection of such proxies would raise

serious concerns about the uniformity

and reliability of the type A model

results. Moreover, developing guidance

on selection of proxies would be

impractical given the extremely wide

range of hazardous substances and the

diversity of their relevant attributes.

Therefore, for chemical releases,

trustees may only use the models if the

released material is one of the specific

chemicals listed in the database.

As discussed in Section I.C. of this

preamble, use of the models for oil

discharges is governed by NOAA’s OPA

rule rather than by today’s final rule.

However, the Department notes that it

has expanded the database to include 33

types of oils that cover a broad range of

chemical and physical characteristics.

Comment: Some commenters stated

that trustees should be allowed to use

the type A models and obtain a

rebuttable presumption for releases that

did not originate in, but later migrated

into, a coastal or marine or Great Lakes

environment. These commenters argued

that the type A models could

accommodate such releases. On the

other hand, one commenter thought that

such use should not be allowed because

there are no data on conditions outside

the boundaries of the type A models.

Response: The Department has

concluded that the type A models can

produce reliable damage figures for

releases that do not originate in, but do

migrate within, the boundaries of the

models provided that the user supplies

appropriate data inputs. So long as the

user supplies data inputs that reflect

conditions at the point that the

substance enters the model boundaries,

the models are just as capable of

computing reliable damages as they

would be if the release had actually

started at that point. In such cases, the

models will start their simulations at the

point that the released substance enters

water within a geographic region

represented in the models. The only

potential problem is that the models

will not account for the effects produced

before the release entered the model

boundaries, a consideration that may

support use of type B procedures in

some cases. However, the Department

believes trustees should have the option

of using the models to assess such

releases when the cost of performing

type B procedures to develop a more

complete damage figure is not

reasonable.

Therefore, the rule allows trustees to

use the models for releases that occur

outside the boundaries of the models so

long as the user-supplied inputs

appropriately reflect conditions at the

point that the substance entered such

waters rather than the point of the

original release. Appendices II and III

specify that when using the models for

releases that originate on land or outside

the model databases, trustees must

adjust the data inputs.

Comment: One commenter said that

the definition of ‘‘minor’’ was vague, but

supported the Department’s discussion

of it and the proposal to allow trustees

discretion to define ‘‘minor’’ on a caseby-case basis. Other commenters,

including one of the independent

technical reviewers, thought that the

Department should define ‘‘minor.’’ One

commenter suggested that the rule

require trustees to justify their

determination of whether a release is

minor with scientific documentation.

Another comment recommended the

Department define ‘‘minor’’ based on

spill size, prediction of affected area, or

resulting damage estimates.

Response: In light of Congressional

intent to restrict use of type A

procedures to minor releases and after

considerable analysis and deliberation,

the Department has decided to impose

a specific dollar cut-off for use of the

models to obtain a rebuttable

presumption. The final rule provides

that if the model output indicates

damages in excess of $100,000, then

trustees who wish to obtain a rebuttable

presumption must either: (1) limit the

portion of their claim calculated with

the type A procedure to $100,000; or (2)

compute all damages using type B

procedures. The Department believes

this provision establishes an appropriate

standard of fairness for allowing trustees

to receive a rebuttable presumption for

damages calculated by the NRDAM/

CME or NRDAM/GLE given the current

level of experience with these models.

The language and legislative history

of CERCLA indicate that Congress

intended the type A procedures as a tool

for obtaining a rebuttable presumption

in cases of minor releases. Thus, the

Department included a provision in the

proposed rules that prohibited trustees

from using the models to obtain a

rebuttable presumption unless the

release was minor. The proposed rule

provided no definition of ‘‘minor,’’ and

the Department indicated in the

preamble to the proposed rules that it

had been unable to develop a uniform

standard for all substances and areas

encompassed by the models. See 59 FR

at 40330 and 63313. However, after

reviewing the comments, the

Department has concluded that given

the significance of this term and the fact

that type A procedures were intended as

simplified procedures requiring limited

analysis by trustees, it is appropriate to

provide clear guidance.

The Department evaluated a number

of different approaches to defining

‘‘minor.’’ First, the Department

reviewed the language and legislative

history of CERCLA. The Senate Report

that accompanied the predecessor bill to

CERCLA states:

[A] simplified type of regulation is

necessary to effectively deal with damage

assessment in most ‘‘minor’’ releases of

hazardous materials * * *. The other type of

regulations [type B] would be employed in

large or unusually damaging releases and

would be used to guide the site-specific

damage assessment. S. Rep. No. 96–848 at 86.

However, nothing in the legislative

history indicates what Congress meant

by ‘‘minor.’’

Next, the Department considered

basing the definition on the technical

limitations of the NRDAM/CME and the

NRDAM/GLE for modeling large or

highly toxic spills. However, sensitivity

analyses of the models failed to reveal

any clear stages at which the model

assumptions became invalid.

The Department then considered

relying upon existing standards

developed in other contexts of

environmental law. The U.S. Coast

Guard has developed a volume-based

system for classifying oil spills for

purposes of spill response. See 40 CFR

300.5 (minor discharge of oil is one of

less than 1,000 gallons to inland waters

or 10,000 gallons to coastal waters). The

U.S. Environmental Protection Agency

(EPA) is responsible for developing a

parallel rating system for hazardous

substance spill response. While EPA has

developed a qualitative system, this

system does not provide the type of

clear, quantitative limits that the

Department believes are needed in this

context. See 40 CFR 300.5 (minor

release of hazardous substance is one

that poses minimal threat to public
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20581

health or welfare of the U.S. or the

environment).

Next, the Department considered

basing a definition of minor on the point

at which type B procedures can no

longer be performed at a reasonable

cost. However, because trustees have

rarely pursued damage claims for

smaller spills, the Department was

unable to develop reliable estimates of

the cost of conducting type B

procedures in such cases.

Therefore, the Department was left to

make this policy decision about the

upper limit on applicability of type A

procedures without the benefit of clear

empirical standards or legal precedents.

The Department has chosen to base this

limit on its sense of when it is no longer

‘‘fair’’ to allow trustees to obtain a

rebuttable presumption using the

NRDAM/CME or NRDAM/GLE as

opposed to performing type B

procedures. The Department believes

that, given the current level of

experience with these models, $100,000

represents a reasonable cut-off for their

use. As more experience is gained with

these models, the Department will

reconsider this cut-off in future biennial

reviews. Further, because this regulatory

cut-off is based on considerations of

fairness rather than the inherent

reliability of the models, the Department

wishes to emphasize that although use

of the models to calculate damages

above $100,000 is not entitled to a

rebuttable presumption, such use may

nonetheless be appropriate in other

contexts, such as settlement

negotiations or litigation without the

benefit of the rebuttable presumption.

Finally, the Department recognizes

that in some instances the models may

project damages in excess of $100,000,

yet it may not be reasonable to perform

type B procedures. The Department

believes that trustees should be allowed

the option of claiming damages up to

$100,000 in such cases instead of

forgoing all compensation. Therefore,

the Department has eliminated the

proposed rule condition that type A

procedures only be used for minor

releases and instead imposed a cap on

the level of damages that trustees can

claim through use of a type A procedure

and still obtain a rebuttable

presumption.

Comment: Several commenters

thought that the proposed condition

requiring uniform subsurface currents

would render the NRDAM/CME

inapplicable to all spills in

Massachusetts, New Hampshire, and

Maine.

Response: The Department

acknowledges that the condition

regarding subsurface currents may limit

the applicability of the NRDAM/CME in

some circumstances but notes that it

does not render the model inapplicable

to all locations where subsurface

currents are not uniform. The models

use vertically averaged currents and

assume that the speed and direction of

horizontal transport is uniform over

depth at a specific latitude and

longitude. The models do include

randomized motion in the vertical

dimension, but not directed motion. The

vertically averaged current is essentially

a current that provides the correct net

transport averaged vertically. If the

transport of the released substance

cannot be reasonably represented by a

vertically averaged current, then the

NRDAM/CME’s projections may not be

reliable. For example, substances with

high densities, such as sulfuric acid,

may sink rapidly through the water

column so that the principal mass is

transported in the direction of the

subsurface current. However, in many

cases, such as when a substance remains

at or near the surface or sinks slowly,

subsurface currents will not affect the

fate of the spilled substance. In these

cases the model can reliably predict

damages. Therefore, the rule allows

trustees to use the NRDAM/CME, even

if subsurface currents are not uniform,

so long as they are not expected to

significantly affect the level and extent

of injuries.

D. User-Supplied Information

Comment: Several commenters

suggested changes to the proposed

models and rules that would require

trustees to confirm injury. These

commenters asserted that the proposed

models merely assume injury and that

the proposed rules inappropriately

failed to require field verification of this

assumption. The commenters noted that

CERCLA limits recovery to damages that

‘‘result from’’ a release. These

commenters argued that this limitation

requires that trustees conduct field

studies that prove that an injury actually

occurred and that it was caused by the

release in question.

A number of commenters thought that

Congress intended traditional tort law

standards of causation to apply to

natural resource damage cases and cited

case law in support of this position.

Some commenters noted that Ohio v.

Interior rejected a challenge to the

Department’s strict acceptance criteria

for determining injury under the type B

procedures and upheld the

Department’s interpretation that

CERCLA adopted traditional causation

standards. 880 F.2d at 471. The

commenters stated that CERCLA does

not create a different standard of proof

of causation when type A procedures, as

opposed to type B procedures, are used.

Several commenters observed that

CERCLA calls for type A procedures

that involve ‘‘minimal’’ rather than ‘‘no’’

field observation. The commenters

thought that the Department was

engaging in sheer speculation when it

asserted in the August 8, 1994, notice of

proposed rulemaking that requiring

confirmation of injury in type A

assessments would be unduly

burdensome. Finally, the commenters

stated that none of the steps that

trustees must take before applying a

type A model, including the

Preassessment Screen Determination,

satisfy the required standard of

causation.

Response: The type A models do not

‘‘assume’’ that injury occurs. Using both

the information provided by the trustees

and the biological and environmental

information about the spill site

contained in the model databases, the

models perform millions of calculations

to determine whether or not the release

has caused an injury. The models

project the distribution of the released

substance over space and time, track the

changing toxicity of the substance over

that space and time, and simulate the

movements of biota throughout the area

around the release. The models only

conclude that injury has occurred if

biota are exposed to the released

substance at concentrations and

durations that exceed acute toxicity

thresholds. If such thresholds have not

been exceeded, the models conclude

that there has been no injury. The

models can and have projected that no

injury resulted from particular releases.

In such cases, the models determine that

damages equal zero.

The issue is not whether the

Department is attempting to excuse

trustees from their legal requirement to

prove causation; the Department agrees

that trustees must demonstrate that

injury resulted from a release. Rather,

the issue is whether trustees should be

allowed to use the type A models to

make that demonstration. The

Department believes that it is

appropriate to allow trustees to use a

type A model to demonstrate injury

without on-site verification of the model

projections.

There is a tension between the

statutory provision requiring trustees to

demonstrate that injury ‘‘resulted from’’

a release and the provision requiring the

development of simplified assessment

procedures that involve ‘‘minimal field

observation.’’ As noted in the cases

cited by commenters, the requirement

that trustees demonstrate that injury

resulted from the release indicates that
20582 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

Congress intended that natural resource

damage liability be compensatory. PRPs

are to be held liable not just because

they are responsible for a release but

because they are responsible for a

release that caused an adverse effect. On

the other hand, by requiring the

development of type A procedures,

Congress recognized that assessment

work can be expensive and timeconsuming. In the case of minor

releases, it is often not cost-effective or

feasible to conduct more than minimal

field observations. The Department has

struggled to resolve the tension between

these two statutory requirements by

developing type A procedures that rely

on computer models to predict actual

site-specific effects to the maximum

extent practicable but do not require onsite verification of the models’ injury

predictions.

Although the regulations do not

require trustees to verify the injury

projections of the type A models, they

do require trustees who use a type A

model to make several determinations

that require field observations. Before

trustees can proceed with a type A

procedure, they must perform a

Preassessment Screen Determination in

which they establish if assessment work

is warranted. Existing § 11.23(e) requires

trustees to make a preliminary

determination that the following

conditions have been met:

A release of a hazardous substance has

occurred; Natural resources under their

trusteeship have been or are likely to have

been adversely affected;

The quantity and concentration of the

released substance is sufficient to potentially

cause injury;

Data sufficient to pursue an assessment can

be obtained at a reasonable cost; and

Response actions will not sufficiently

remedy the injury.

If the trustees determine that these

conditions are met, they must then

demonstrate that the released substance

entered the water, which is the only

pathway considered by the models.

Trustees must develop information on

ambient environmental conditions at

the site of the release and on the extent

of response actions. Also, trustees must

evaluate whether potentially affected

resources are addressed by the model.

The Department agrees that these

determinations in and of themselves do

not establish causation. They are not

intended to do so; causation is

demonstrated by the models. However,

these determinations do fulfill the

standard of minimal field observations.

The Department notes that Congress

chose to use the word ‘‘observations’’

rather than ‘‘studies,’’ ‘‘surveys,’’ or

‘‘analyses.’’ Therefore, the Department

interprets ‘‘minimal field observations’’

to be information that is readily or

routinely collected following a release.

The Department rejects the argument

that the language of CERCLA requires

on-site verification of causation, since

observations would often be inadequate

to determine causation. For example,

the released substance may sink or

disperse into the water column,

precluding visual methods for

documenting pathways and exposure.

Furthermore, the potentially exposed

resources may be difficult and costly to

sample (e.g., endangered species,

marine mammals, or subtidal

organisms). In other instances, the

persistence of the substance, or the

remote location of the release, may

prevent trustee scientists from reaching

the spill site in a timely manner to

conduct assessment work.

Moreover, today’s final rule does not

establish a new standard for proof of

causation. The regulations did not

require trustees to verify the injury

projections of the original NRDAM/

CME. The existing regulations require

trustees to confirm exposure before

implementing type B studies, but not

type A procedures. Today’s final rule

does include language in § 11.31(c)(1)

clarifying that the confirmation of

exposure requirement only applies to

type B procedures. The original type A

rule contained the same substantive

provision, only worded differently. See

52 FR at 9064. This final rule simply

rewords and relocates the existing

provision.

Even when trustees use type B

procedures, there are some

circumstances under which the existing

regulations allow them to use models to

determine injury to surface water,

groundwater, and air. See 43 CFR

11.64(b)(6), 11.64(c)(8), and 11.64 (d)(2).

The existing regulations also allow

trustees who perform type B procedures

to use models to demonstrate that a

groundwater or air pathway exists

between the site of the release and

injured biological resources. See 43 CFR

11.63(c)(5)(ii)(C) and 11.63(d)(4).

Demonstration of a pathway is an

integral part of establishing causation.

The Department acknowledges that

the existing regulations do not explicitly

allow trustees who use type B

procedures to demonstrate biological

injury based on models alone. However,

as Ohio v. Interior recognized, the

language and legislative history of

CERCLA are ambiguous as to the

standard of proof of causation. 880 F.2d

at 470. Nothing in the statutory language

prohibits the Department from

establishing different standards of proof

of causation under type A and type B

procedures, and the Department

believes that in light of the statutory

description of type A procedures,

different standards are warranted. In

fact, as discussed above, the legislative

history of CERCLA suggests that the

Department would have been justified

in developing a look-up table or

compensation formula as a type

Aprocedure. Instead, the type A models

use both site-specific information

provided by the trustees and biological

and environmental information about

the spill site contained in the databases

to approximate more precisely the

actual effects of the release.

Finally, the Department notes that the

final rule has been revised to require

trustees to perform a preliminary

application of the model and make the

results available for public comment

before presenting a damage claim.

Therefore, PRPs will have an

opportunity to evaluate the injury

projections. They can then decide

whether they have information that

indicates that the projections are wrong

and that the user inputs need to be

modified or that type B procedures

should be used.

Comment: The Department received

several comments on the wind inputs.

Some commenters expressed concern

about the adequacy of the proposed rule

language allowing trustees to supply

one set of wind data for a 30-day period.

These commenters noted that wind data

were critical to correct functioning of

the models and requested that trustees

be required to supply actual hourly

data. One commenter noted that such

data are readily available from the

National Climatic Data Center. These

commenters also thought that actual

wind data should be supplied for the

entire duration of the model application

because of gross oversimplifications in

the data supplied by the models when

the user-supplied wind data run out.

One of the independent technical

reviewers suggested that users be

allowed to enter wind data in their

choice of units.

Response: The Department agrees that

one set of wind data for an entire 30-day

period may not be adequate in all cases.

Trustees are free to supply hourly wind

data; however, the Department also

believes that requiring trustees to do so

in all cases would be onerous.

Therefore, the Department has modified

the final rule to require trustees to

supply data on prevailing wind

conditions for each day of the 30-day

period. Recognizing that the type A

procedures were intended to provide

simplified procedures requiring

minimal analysis by trustees, the

Department has concluded that it is
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20583

appropriate to establish a uniform time

frame for entry of wind data. Wind

speed and direction are most relevant to

the simulation of the surface trajectory.

Released substances will generally only

float for a few days or weeks before they

sink or go ashore. Therefore, the

Department believes that 30 days is an

appropriate time frame for the vast

majority of releases to which the type A

models will be applied. Users are free to

supply more than 30 days worth of

wind data if they choose but are not

required to do so. If a simulation

continues past 30 days and the user has

only supplied 30 days worth of data, the

models will supply climatological wind

data. With regard to the units of

measurement for wind data, the

Department notes that users are allowed

to enter wind data measured either in

knots or in meters per second. The

Department believes this provides users

with appropriate flexibility.

Comment: Several commenters

addressed the currents inputs to the

proposed NRDAM/CME. Some

commenters, including a few of the

independent technical reviewers, found

it difficult to enter currents data and

suggested that default values be made

available. On the other hand, one

commenter thought that the tool for

supplying currents data in the proposed

NRDAM/CME was already too

simplistic. One of the independent

technical reviewers noted a ‘‘bug’’ in the

program.

Response: Currents have a profound

impact on the physical fate of spilled

substances and are highly variable.

Provision by the model of a single set

of default values for currents would

adversely affect the reliability of the

model. Therefore, the Department

believes it is appropriate to require

users to supply some level of sitespecific data on currents. However, the

Department is also committed to

ensuring that the NRDAM/CME remain

accessible to a wide range of potential

users and, thus, recognizes the need to

avoid excessively complicated user

inputs. The Department has revised the

currents entry tool to make it easier to

use and to correct the ‘‘bug.’’ The

Department has also provided

additional guidance on developing and

entering currents files in Volume II of

the NRDAM/CME technical document.

Comment: Some commenters objected

to the proposed provision allowing

trustees to decide whether or not to

have the models consider ice cover.

These commenters stated that the rule

should require trustees to have the

models consider ice cover if ice is

present during or after the release.

Response: The Department believes

that the ice model contained in the

NRDAM/CME and NRDAM/GLE

reasonably reflects average ice

conditions. However, the Department

has modified the final rule to provide

that when trustees have reliable

evidence that ice was not present at the

spill site, they must disable the ice

modeling function.

Comment: A few commenters

addressed the data inputs for response

actions. One commenter thought that

the models should take into account the

effects of spill prevention and

containment measures required under

OPA and other laws. Some commenters

stated that trustees should only be

required to supply the volume of the

released substance that was removed

during the first 24 hours after the

release. These commenters noted that

the types of acute effects considered by

the models should have occurred within

that first 24-hour period.

Some commenters thought that

limiting the data inputs to the first 24

hours would also alleviate the problem

with the NRDAM/CME identified in the

December 8, 1994, preamble. In that

preamble, the Department noted that

there may be cases where the proposed

NRDAM/CME would not subtract the

full volume removed even though users

had provided full and accurate

information about removal actions. This

problem arose because the proposed

model required users to specify the

location and time frame of the removal.

The proposed model then subtracted the

mass removed at the time and location

specified by the user. If the user

specified that mass was removed from a

location before the time that the model

projected the substance would reach

that location, then the model was

unable to subtract any removed mass.

See 59 FR at 63307–08. Another

commenter expressed concern about

this problem and suggested modifying

the NRDAM/CME so that in such a

situation the volume of the released

substance actually removed would be

subtracted from the nearest location

where the model predicted that an

equivalent volume of the substance

could be found at that time.

Response: The final rule and models

do account for the effects of successful

spill prevention and containment

measures. The models calculate

damages only for the volume of

substance that entered the water, was

not removed, and caused injury.

Therefore, any material prevented from

entering the water as a result of

voluntary or mandatory spill prevention

or containment measures would not be

considered by the models.

With regard to entry of data on

removal that occurred more than 24

hours after the initial release, the final

rule requires trustees to specify the time

of the removal. Therefore, even for

injuries that do occur within the first 24

hours, entry of the total volume

removed would not result in an

underestimate of damages because the

models will take into consideration that

the removal did not occur entirely

within the first 24 hours. The

Department assumes that the

commenter’s concern is that the models

will underestimate damages if they

subtract the entire volume removed

because only the removal during the

first 24 hours would reduce the

likelihood of acute injury. However, not

all direct effects considered by the

models will occur within the first 24

hours after the release.

To address the problem identified in

the December 1994 preamble, the

Department has modified the final rule

language addressing the required data

input for response actions. Appendix II

now states that when developing the

data input on response actions, trustees

must specify a geographic area that

encompasses the entire surface water

and shoreline area over which the

spilled substance was likely to have

spread. This requirement should ensure

that the NRDAM/CME will subtract the

full volume of spilled material that was

removed during response.

Comment: Numerous commenters

addressed whether users should be

allowed to modify the model databases.

One commenter suggested that the

models would be too labor-intensive if

trustees were expected to edit numerous

databases. However, most commenters

supported retaining the habitat editor in

the final version of the models, noting

the prevalence of default values in the

habitat database. Some commenters,

including one of the independent

technical reviewers, stated that the

Department should continuously update

the model databases to ensure that they

reflect current information. Other

commenters expressed doubt that the

Department could conduct such updates

in a timely manner. These commenters

thought that model accuracy would be

increased if trustees were allowed to

edit not only the habitat designations

but also other data such as species

biomass, baseline fishing mortality

rates, commercial fish prices, and

restoration costs. These commenters

noted that PRPs would be protected

from potential misuse of the editing

feature by trustees because the input

data would be subject to challenge.

Some commenters recommended

various mechanisms for allowing users
20584 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

to substitute more precise or up-to-date

site-specific information. For example,

one commenter suggested creating an

administrative process for obtaining

variances from the model parameters or

data.

Response: The Department

acknowledges that allowing users to

revise the models’ databases would

enable fine-tuning to better reflect sitespecific conditions. On the other hand,

Congress specifically mandated the

development of type A procedures to

simplify assessments and minimize

fieldwork. The more trustees are

expected to edit the model databases,

the less the type A procedures fulfill

this mandate and the closer such

procedures approach the data-gathering

requirements of type B procedures.

Therefore, the Department has

decided to allow trustees to modify,

under some circumstances, the models’

default values for water temperature,

total suspended sediment

concentrations, mean settling velocity of

suspended solids, air temperature, and

habitat type. However, trustees may not

make any additional modifications to

the databases if they intend to obtain a

rebuttable presumption.

The proposed rules included

provisions allowing trustees to supply

site-specific values for water

temperature, total suspended sediment

concentrations, mean settling velocity of

suspended solids, and air temperature.

The Department continues to believe

that these parameters are highly variable

and can profoundly affect the physical

fate of released substances. Therefore,

trustees should be allowed to change the

default values for these parameters if

they have more accurate data.

The Department has also concluded

that retention of the habitat editor is

appropriate given the importance of

habitat designations to the total damage

figure and the prevalence of default

habitat designations in the models.

Also, despite specific solicitations in

both notices of proposed rulemaking,

relatively few commenters supplied

revised habitat information to the

Department and some State commenters

specifically stated that they had been

unable to review the habitat

designations.

The Department does not believe that

the habitat editor requires excessive

effort to operate. First, trustees are not

required to edit habitat designations.

Second, while the task could be

substantial if a single user attempted to

edit the large regions covered by the

models, it is not so labor intensive for

the area actually affected by any single

spill. The Department also notes that

trustees often perform habitat mapping

as part of pre-spill planning, which

should further expedite habitat editing.

Once edited, the revised habitat

designations may be saved within the

models and used again for future model

applications. However, trustees who

save such redesignations would still

need to justify those redesignations in

any future Assessment Plans.

With regard to other model databases,

the Department believes that allowing

additional editing would undermine

Congress’ intent for developing type A

procedures. Allowing other edits would

require users to make additional

conforming changes that would

complicate use of the models. For

example, changing the fisheries biomass

or parameters would require

recalculation of egg and larval

abundance using the model equations.

Changing wildlife abundances would

require recalculation of lost wildlife

viewing values.

The final rule no longer requires use

of the type A models. Therefore, when

trustees have, or are provided with,

evidence that the model databases are

inaccurate for a specific incident, they

are free to use type B procedures,

provided they can do so at a reasonable

cost. When trustees or PRPs already

have site-specific information indicating

that model data are inaccurate, the cost

and effort associated with conducting

type B procedures, and in turn the need

for a type A procedure, should be

reduced.

The Department does not have the

resources available to support an

administrative process for reviewing

petitions for variances from the

computer model parameters or

databases. However, the Department is

statutorily required to review and

update the models every two years and,

thus, will be incorporating more up-todate information as it becomes

available. Also, the Department notes

that the models already update the

compensable value and restoration cost

databases to account for inflationary

effects through application of the

implicit price deflator. Finally, the

Department notes that while the results

of model runs made with customized

changes beyond those identified in the

rule would not receive the rebuttable

presumption for damage claims made

under CERCLA, they may nonetheless

be reliable and useful in other contexts,

such as settlement negotiations or

litigation without the benefit of the

rebuttable presumption.

Comment: A few commenters

addressed the implicit price deflator

data input. In response to the

Department’s solicitation of comment

on whether the proposed rules should

be modified to require trustees to supply

the implicit price deflator for the Gross

Domestic Product (GDP) instead of that

for the Gross National Product (GNP),

one commenter indicated that use of the

implicit price deflator for the GNP

should be retained. Another commenter

stated that the Department should

change the base year from 1987 to 1992.

Response: The Department has

decided to retain the GNP implicit price

deflator as the index with which to

adjust past dollar amounts to current

dollar equivalents. Because GNP refers

to income that is available to U.S.

residents, it is appropriate for analyses

that are related to the use of that

income, such as expenditures for

environmental restoration. GDP, on the

other hand, refers to income that is

derived from production within the

U.S., regardless of whether that income

is available to U.S. residents or accrues

to non-U.S. residents. For more

information regarding GNP and GDP,

readers are referred to the August 1991

issue of the Survey of Current Business

available from the Bureau of Economic

Analysis, U.S. Department of

Commerce. Also, the Department has

updated the index numbers in the

models to accommodate the change in

base year from 1987 to 1992.

Comment: One of the independent

technical reviewers questioned the user

inputs to the proposed NRDAM/CME

concerning boat closures. The technical

reviewer thought that it might be

difficult for trustees to estimate the

number of boats affected by the closure.

Response: As discussed in Section

VII.P of this preamble, the Department

has eliminated the calculation of

damages for lost boating from the

NRDAM/CME.

Comment: A few commenters

responded to the Department’s

solicitation of comment on whether

users should be allowed to supply a

site-specific discount rate and, if so,

how they should determine the correct

rate. These commenters stated that the

models should use a fixed discount rate

but that the fixed rate should be three

percent rather than the seven percent

rate included in the proposed models.

Response: The Department believes

that the appropriate discount rate is the

consumer’s rate of time preference for

natural resource services. This is the

rate at which individuals are willing to

trade natural resource services today for

similar natural resource services in the

future. The Department further believes

that the real (inflation-adjusted) rate of

return on U.S. Treasury bills is a

reasonable proxy for this rate of time

preference. An analysis of real rates of

return on U.S. Treasury bills reveals an
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20585

indicated annual discount rate of three

percent. Therefore, the Department

agrees with the commenters that future

lost use values should be discounted at

a three percent rate. This discount rate

has been incorporated in the models.

The Department believes that use of a

fixed discount rate is appropriate in the

context of a simplified procedure.

Further, the Department believes it is

unlikely that the rate will change

significantly over the next two years.

During the biennial review, the

Department will reexamine this issue.

E. Physical Fates

Comment: Several commenters,

including some of the independent

technical reviewers, thought the

physical fates submodel was well

developed and well tested. Another

commenter stated that the proposed

models produced spill trajectories that

resembled actual spill events.

Conversely, one commenter experienced

difficulty with the models’ trajectory

component noting that, during some

trial runs, the spill did not move.

Response: The Department

acknowledges and appreciates the

supportive comments concerning the

physical fates submodel. Physical fates

modeling is a technical discipline that

has received extensive study. In reply to

the trajectory difficulty, the Department

notes that the model’s spill trajectory is

dependent upon the user’s entry of

wind and current data. Spilled material

does not move during simulations if the

user does not supply wind and current

data.

Comment: Several commenters,

including some of the independent

technical reviewers, were disappointed

by coarse resolution of most habitat

grids in the NRDAM/CME. These

commenters complained that the

limited resolution results in the loss of

consideration of critical shoreline

habitats.

Response: The Department has

improved the resolution in the NRDAM/

CME by a factor of four through use of

a new compiler and additional memory.

Comment: Several commenters

claimed the proposed models used

inadequate and nonrepresentative data

on the physical and chemical properties

of hazardous substances and oil and

provided references to additional data

sources. The commenters stated that the

chemical and physical data on gasoline

and diesel oil, particularly the sulfur

content in diesel oil and vapor pressures

in gasoline, do not accurately represent

the products in use today. One of the

independent technical reviewers stated

that the relative toxicities used in the

models for No. 6, No. 2, and crude oils

do not agree with experiment results

reported in the literature. Several

commenters also concluded the

Department inappropriately applied the

same degradation rates to the nine oils

included in the models (except for No.

2 diesel oil). They could not

substantiate the model degradation

rates, and concluded they were invalid.

One of the independent technical

reviewers suggested that the Department

update the parameters for oils. Some

commenters also thought that the

models relied on overly simplistic and

outdated modeling techniques.

Response: The Department found the

physical and chemical parameters

included in the models for hazardous

substances to be in agreement with

commenters’ independent literature

search, except with regard to the

partition coefficient for

epichlorohydrin. After reviewing the

literature, the Department has decided

to substitute the proposed parameter for

this substance.

The Department has also increased

the number of oils and petroleum

products included in the models to a

total of 33 and has revised the physical

and chemical parameters for oils based

on the most recent literature. The

degradation rates for oils in the models

apply to acutely toxic low molecular

weight components. Thus, they are

consistent for all oils. The Department

reviewed the accuracy of these data and

documented all sources in the technical

documents when revising the oil

database. For further information, see

Section 2, Volume III of the NRDAM/

CME and NRDAM/GLE technical

documents.

The Department does not agree that

the modeling techniques used are either

outdated or overly simplistic. The

Department has never intended the

physical fates submodel, or any of the

other submodels, to provide a

comprehensive treatment of all known

physical, chemical, and biological

processes occurring in aquatic

environments, nor is such treatment

necessary for the limited purposes of the

type A procedures. Instead, the

modeling techniques employed are

intended to reasonably approximate the

most relevant processes pertaining to

the fates and effects of spills that occur

in aquatic environments based on

readily available user input data.

Comment: One commenter thought

that the models overstated wildlife

injuries by inappropriately treating

chemicals less dense than water as

slicks. The commenter also stated that

the proposed models’ predictions of oil

and chemical slicks failed to account for

many of the physical processes that

affect the size of the surface slicks.

Response: The models do treat all

chemicals that are lighter than water as

‘‘slicks.’’ However, chemicals that are

very soluble, such as ethanol and

ammonia, will very quickly mix into the

water column. Thus, chemicals that are

highly soluble do not remain on the

surface long enough to have any direct

effect on wildlife at the water surface.

The Department disagrees that the

models do not adequately account for

the physical processes affecting surface

slicks. The major processes affecting the

size of surface slicks are spreading,

evaporation, and entrainment, all of

which are simulated in the models. For

further discussion, see Sections 3.3

through 3.5, Volume I of the NRDAM/

CME and NRDAM/GLE technical

documents.

Comment: One commenter referred

the Department to the Ohio spill

database as an additional source of

information.

Response: The Department took this

database into consideration when

determining the types of spills to use for

the sensitivity analysis of the NRDAM/

GLE.

Comment: One commenter questioned

whether the use of varying grid sizes

makes the NRDAM/GLE less accurate

for spills in areas of large grid size.

Response: The Department designed

the grid sizes to represent the Great

Lakes habitats at a resolution required

by the local spatial variability. Areas

with more spatial variability have

smaller grids and higher resolution. The

areas with large grid sizes are the open

lakes where fine detail is not necessary.

Thus, the NRDAM/GLE is not less

accurate in the areas where grids are

largest.

Comment: One commenter questioned

why the Department did not incorporate

the U.S. Army Lake Survey grid in the

NRDAM/GLE.

Response: Development of the

NRDAM/GLE grid required the

representation of spatially varying

habitats and depths as well as the

contours of the connecting channels

within a regular rectangular grid system.

The U.S. Army Lake Survey grid does

not consistently meet this requirement.

Moreover, the Department has no reason

to believe that use of the U.S. Army

Lake Survey grid would significantly

improve the reliability of the NRDAM/

GLE.

Comment: A few commenters,

including one of the independent

technical reviewers, thought that the

Department should use threedimensional hydrodynamics models.

Several commenters thought the
20586 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

proposed type A models unrealistically

assumed that currents were uniform

with depth; unjustifiably failed to

incorporate three-dimensional currents

modeling; and inappropriately failed to

account for the effects of wind-driven

turbulence mixing processes that

increase mixing as high winds make the

water surface rough. One commenter

stated that a three-dimensional

hydrodynamics model was needed to

account for the effects of seiches (i.e.,

occasional and sudden oscillations of

the water of lakes, bays, or estuaries

caused by wind or changes in

barometric pressure).

Response: The NRDAM/CME and

NRDAM/GLE use a three-dimensional

transport model. The transport model

assumes that currents are uniform

vertically at each horizontally defined

location. If the Department did include

a three-dimensional current dynamics

model in the NRDAM/CME and

NRDAM/GLE, then users would need

the assistance of expert hydrodynamic

modelers to operate the type A models.

For example, three-dimensional current

dynamics models are dependent on

physical forces at the boundaries of the

modeled area, which the user would be

required to enter. The Department

believes that imposing such complex

modeling requirements would conflict

with the statutory directive to develop

simplified assessment procedures.

The models utilize vertically averaged

currents with the assumption that

horizontal transport is uniform in speed

and direction over depth at a given

location in horizontal space (i.e., at a

given latitude and longitude). One of the

conditions for use of the models is that

subsurface currents either are not

expected to significantly affect the level

and extent of injuries or are reasonably

uniform with depth in the area of the

spill. The models also include

randomized motion in the vertical

dimension, but not directed motion in

the vertical. Thus, the currents carrying

spilled material must be representable

in a manner consistent with this

assumption of the models.

The vertically averaged current is

essentially a current that provides the

correct net transport, averaged

vertically. If the transport of spilled

material cannot be reasonably

represented by a vertically averaged

current, the condition for use would not

be met and the model would not be

applicable. However in many cases,

three-dimensional representation of

current dynamics would not

significantly change the damages

calculated by the models. For example,

for substances of low density, such as

toluene, that remain at or near the

surface, the present current dynamics

model adequately addresses physical

fates.

The Department recognizes that

seiches occur in the Great Lakes. The

Department has not, however, included

such processes in the NRDAM/GLE

because these processes are not a

significant transport process for

determining the physical fate of spilled

substance in the Great Lakes. Further,

any change in the location of a shoreline

brought about by a seiche is likely to be

small and should not have a significant

effect on the injuries calculated by the

model.

Comment: One commenter thought

that the models should not include

liquid asphalt. The commenter noted

that liquid asphalt hardens and sinks to

the bottom quickly, and can be

completely removed by dredging.

Response: The Department agrees that

the models are not designed to estimate

damages for substances such as liquid

asphalt. The models assume that oils

and petroleum products float initially,

although they may subsequently

entrain, adsorb to particles, and sink.

Liquid asphalt does not act in this

manner and, thus, has not been

included in the databases.

Comment: One commenter criticized

the NRDAM/CME’s treatment of ice,

stating that the model inappropriately

assumes that ice is always a solid mass.

Response: The model does not assume

that ice is always a solid mass. For a

discussion of how the models treat ice,

see Section 3.11, Volume I of the

NRDAM/CME and NRDAM/GLE

technical documents.

Comment: Some commenters thought

a smooth function relating requisite

thickness to spillet diameter would be

more realistic than the step function

proposed in the models.

Response: Not enough quantitative

information is available to develop a

smooth function. Available data are, in

fact, in the form of a step function.

Further, given the available data and the

steepness of the relationship between

mortality and dose in the pertinent

range, the form of the function would

not significantly affect the reliability of

the model calculations.

Comment: One of the independent

technical reviewers noted that the

proposed NRDAM/CME treated

wetlands as water cells and questioned

why they were not oiled as other

shorelines.

Response: Wetlands are either

fringing or extensive in the model.

‘‘Fringing’’ wetlands are those which

form narrow wetlands along shorelines.

‘‘Extensive’’ wetlands, on the other

hand, are those sufficiently large to

encompass a majority of the grid cell.

For fringing wetlands, oiling occurs in

the same manner as for other shorelines.

For extensive wetlands, slicks keep

moving across the area, as they do in

water, but they can oil wetland biota in

the same way as they do in fringing

wetlands. Oil may accumulate in

sediments in all cells, by partitioning

onto suspended sediments and sinking.

F. Species Distribution and Abundance

Comment: Several commenters

thought the default habitat designations

in the NRDAM/CME generally provided

an inadequate representation of coastal

and marine habitats. Others

recommended specific changes such as

including habitat data available in

existing or upcoming studies. One

commenter provided specific habitat

data for New York and New Jersey.

Another commenter requested that the

Department use information that would

be available from the upcoming Texas

Natural Resource Inventory.

Response: As stated in the notices of

proposed rulemaking, the Department

recognized the shortcomings of the

default habitat designations and

specifically solicited comment on those

designations. See 59 FR at 40330 and

63314. The notices also provided

technical instructions on transmitting

information to the Department about

suggested changes to the default habitat

designations. The Department has

reviewed and revised the habitat

designations in the NRDAM/CME based

on technical data provided to the

Department for the coastal and marine

waters of New York and New Jersey.

The Department did not receive other

specific recommendations for changing

the default habitat designations within

the format requested.

The Department recognizes that

additional habitat data are continually

becoming available. However, the

Department needed to finalize the data

in the models and chose not to delay

issuance of the models to incorporate

recent or upcoming studies, such as the

Texas inventory. During future biennial

reviews, the Department will update the

habitat designations to reflect newer

information. Meanwhile, today’s final

rule allows trustees to change the

default habitat designations. As further

studies provide better data, trustees may

substitute such data for the default

values included in the models using the

habitat editor function.

Comment: One commenter stated that

shoreline types in the NRDAM/GLE

should include a cohesive (clay)

component. The commenter also

thought that rocky shoreline should be
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20587

changed to either rocky bluff or cobble

beach.

Response: The Department does not

believe that changes to the shoreline

types are necessary. The suggested

changes would have little impact on the

reliability of the damage figure since

biological injuries are not calculated

based on shoreline designations. The

models use shoreline type to

approximate the oil retention on

shorelines. Further, the distinct holding

capacities for these shoreline types are

unavailable but could be expected to fall

within the holding capacities of the

shoreline types already represented

within the NRDAM/GLE.

Comment: One commenter provided

maps of habitat types for Michigan and

suggested that wetlands in the

connecting waterways be hand-edited.

Response: Although the Department

appreciates the effort provided by the

commenter, the grid scale of the

information was of a much smaller

resolution than that contained in the

NRDAM/GLE and could not be directly

applied to revisions of the habitat grids.

The Department believes the NRDAM/

GLE habitat designations are consistent

with the maps provided, were such

information consolidated at the larger

NRDAM/GLE grid scale. As a result, the

default habitat designations were not

revised in the NRDAM/GLE, and the

Department has not hand-edited the

habitat maps of the connecting

waterways.

Comment: Some commenters,

including one of the independent

technical reviewers, thought that the

models should map the location of

critical habitats, such as bird colonies or

rare communities and plants.

Response: The Department does not

believe it is appropriate, in the context

of developing simplified type A

procedures, to attempt to map all

critical habitats and rare communities

throughout the entire geographic region

covered by the models. The models

were developed based on an assumed

average abundance of biota by habitat

within a biological province. The

Department believes that if a release is

expected to affect a critical habitat or

rare community that is not adequately

represented by the models, then use of

type B procedures should be

considered.

Comment: A number of commenters,

including some of the independent

technical reviewers, identified and

suggested the Department fill data gaps

in fish abundance. Several commenters

believed the fish abundance data in the

models were based on commercial catch

data that were not generated with sound

scientific methods and are known to

have low accuracy. The commenters

stated that the abundance data were

inconsistent with catch data provided

by Federal and State fisheries agencies

and, thus, did not account for variability

in fish populations. The commenters

questioned the level of care and effort

that had gone into estimating total lake

fish stock data in the NRDAM/GLE.

Response: The Department notes that

fishery statistics are collected to fulfill

a variety of different research and

management needs. For the purposes of

these models, fish biomass abundance

was required. However, such data were

not uniformly available for all species

and all geographic regions covered by

the models. As a result, the Department

drew upon available data from State and

Federal fishery management and

research organizations and extrapolated

where needed to fill gaps. The criteria

used for the selection and use of

available data are outlined in Section

6.3, Volume I of the NRDAM/CME

technical document. For all stocks

where the National Marine Fisheries

Service (NMFS) or State agencies have

performed a stock assessment, these

stock sizes were used. The Department

used biomass surveys if stock

assessments were not available. The

Department used catch data only if

these other data sources were

unavailable. Thus, the data are

consistent with that collected by Federal

and State agencies and represent the

best available data for each species

included. Since the most valuable

species in terms of total catch are also

the most studied, data are likely to be

more accurate for valuable species.

Damages resulting from less significant

species in the catch are typically

insignificant.

Where the Department had to use

catch data to estimate biomass, it used

both commercial and recreational catch

data compiled by NMFS, the Federal

agency charged with assessing and

regulating fisheries stock. These catch

data are the best available source of

information. The Department used

commercial catch data as the sole source

of information only where there was not

a significant recreational fishery.

The Department did attempt to

account for variability in fish

populations. The areal extent of a

species and its seasonal movements are

based on life-history information for

that species. Some species do not in fact

move seasonally. Those that do are

indicated in the database. In some cases,

catch from large areas is represented in

smaller areas if the life history warrants.

In other cases, the data are not

supportive of regional specificity. Also,

some stocks do vary annually to a

significant degree. For stocks where data

were available, averages for the most

recent three years were used. The

models are designed to represent an

average year.

Considerable care and effort went into

estimating total lake fish stock data in

the NRDAM/GLE, as documented in

Section 3, Volume III of the NRDAM/

GLE technical document. The

Department considered both the data

available and the species behavior in

terms of habitats utilized by season.

Comment: Some commenters,

including a few of the independent

technical reviewers, questioned the

wildlife abundance data sources used

for determining hunting and trapping

losses. One commenter thought that

some abundance data from one area

were used inappropriately to represent

abundances in other areas. For example,

the commenter noted that the study by

Onuf (1987) was used inappropriately to

extrapolate bird abundances over the

entire west coast; and that the study by

Breuggeman (1989) was used

inappropriately to extrapolate marine

mammal abundances to both the

California coast and to Galveston Bay.

Another commenter questioned the

references to Bellrose (1980),

specifically as applied to trumpeter

swans in Prince William Sound.

Response: The Department has

obtained additional sources of bird

abundance data for the west coast and

has incorporated those data into the

wildlife abundance database of the

NRDAM/CME. Also, the Department has

revised the abundance data for

Galveston Bay to include more recent

data on dolphins. The Department has

included additional osprey data and

updated the eagle and harbor seal data.

Further, the Department has deleted

data for mysticetes (baleen whales) for

provinces 4, 5, and 7. The Department

applied data in Bellrose (1980) only

where no other data were available. The

Department has now replaced most

references to Bellrose (1980) with more

recent data. In particular, the

Department has updated data for Prince

William Sound based on a 1990 to 1995

waterbird survey. For further

information, see Section 5, Volume IV of

the NRDAM/CME technical document.

Comment: One of the independent

technical reviewers thought that the

definition of subtidal wetland was

unclear and recommended that

intertidal seagrass be added as a habitat

type.

Response: Subtidal wetlands are the

subtidal shallow waters in and around

extensive wetlands. The Department has

amended the NRDAM/CME technical

document to include this more precise
20588 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

definition of subtidal wetlands. See

Table 4.4, Volume I, of the NRDAM/

CME technical document. The

Department has also included intertidal

seagrass as an additional habitat type.

Comment: A number of commenters,

including one of the independent

technical reviewers, thought that use of

province-wide abundance figures was

inappropriate given the sizes of the

provinces. An independent technical

reviewer suggested that provinces be

subdivided. Another commenter stated

that grid-specific wildlife abundances

should be used where such data are

available.

For west coast wildlife densities, one

commenter noted that the NRDAM/

CME’s provinces are not consistent with

spatial strata within which seasonal

densities of a species are relatively

uniform. The commenter noted that this

can result in wildlife densities that are

orders of magnitude too high in some

cases or too low in others.

Another commenter pointed out that

the estimates of wildlife seasonal

densities for the west coast were

uniformly high and the numbers

generated by extrapolation of density

may exceed entire world population for

many species. The commenter provided

recent survey density data for birds and

mammals. One of the independent

technical reviewers suggested that the

Department update data on west coast

bird abundances.

Response: The wildlife data for the

west coast and Gulf of Alaska were

completely revised with more recent

and actual survey data provided by one

commenter. Wildlife data for other

provinces were also updated with more

recent information. These corrections

have eliminated the extrapolation errors

noted. The Department believes the

revisions made to the database have

sufficiently addressed the possible need

for subdividing province-wide

abundances. For further information,

see Section 5, Volume IV of the

NRDAM/CME technical document.

Comment: One commenter thought

the way east coast province-wide

wildlife abundances were distributed to

the available individual habitats within

NRDAM/CME grids resulted in an

underrepresentation of wildlife

abundances within the habitat grids.

The commenter noted that individual

habitat grids cannot hold enough habitat

area to add up to the assumed

provincial totals. The commenter

suggested adding a multiplication factor

to correct for the underrepresentation of

habitat area, and resulting proportionate

underrepresentation of wildlife

abundances.

Response: The habitat grid will, by

the fact that it is rectangular, never

precisely represent actual shore length,

which is curved. However, the

Department notes that the NRDAM/

CME’s grid resolution has been

increased by a factor of four and the

habitat data for the area in question

(provinces 11 through 13) have been

revised based on information provided

to the Department. These revisions have

significantly improved the precision of

the shore length estimate. The

Department considered the commenter’s

suggestion of using a multiplication

factor to correct shore width. However,

such a multiplier would affect the

manner in which the physical fates

submodel addresses the oiling of

shorelines and induce additional error

into the calculations performed by the

model. Thus, the multiplication factor

method was not employed.

Comment: A few commenters,

including some of the independent

technical reviewers, suggested that

monthly rather than seasonal averages

be used where such data are available.

Commenters noted that use of monthly

averages was particularly important for

migratory species.

Response: Adequate data do not exist

at this time for most species to

incorporate monthly averages. As more

data become available, the Department

will consider incorporating monthly

averages in the models during future

biennial reviews.

Comment: One commenter questioned

the reliability of the abundance data in

the proposed NRDAM/CME and offered

different data from State wildlife

agencies and available literature. The

commenter recommended the following

changes to the databases: modification

of data for pigeon guillemots and

kingfishers in Puget Sound and the

Straits of Juan de Fuca (province 51)

based on 1994 census data by

Washington State; deletion of data on

puffins along the New Hampshire coast;

modification of data on bald eagles and

osprey in Maryland based on

Maryland’s 1994 census; modification of

data on pelicans and bald eagles in

Florida based on the Florida Natural

Resource Department’s estimates; and

addition of data on Loggerhead and

Kemp’s Ridley turtles for the Gulf of

Mexico and Galveston Bay.

Response: The Department

acknowledges that some errors occurred

during the compilation of the wildlife

abundance database, and additional

information and data sources have been

identified as a result of the public’s

review of these models. In fact, the

Department specifically sought the

assistance of the public on the wildlife

abundance data. See 59 FR at 40330 and

63314. The Department has made a

number of changes to the databases as

a result of the public comments and

now believes that the abundance data

are more reliable.

In response to the specific data

comparisons made by the commenter,

the Department has updated the data for

province 51 and revised seabird

abundances for the northeast. Puffins

are no longer included in province 2,

but are present in province 3, offshore

New Hampshire and Maine. The State of

Maryland’s 1994 census data are more

recent and have been used. The Florida

Natural Resource Department’s 1994

estimates for pelican and bald eagles are

more recent and have been used. The

Department has not included the data

for Loggerhead and Kemp’s Ridley

turtles in the offshore Gulf of Mexico

since these species are not found in

waters greater than 200 meters deep

(NOAA 1985). Also, no data

documenting abundances of these

turtles in Galveston Bay are available.

For further information, see Section 5,

Volume IV of the NRDAM/CME

technical document.

Comment: A commenter thought the

wildlife abundance data were generally

biased.

Response: The Department believes

that the data used in the models

represent the best available information

collected by independent scientists and

government agencies.

Comment: One commenter noted that

the assumption of even distribution and

random movement of biota may not be

true. For example, the commenter noted

that fish eggs and larvae are not

randomly distributed.

Response: Although some biological

populations may not be evenly

distributed and may not move randomly

across large areas encompassing

multiple habitat types, the Department

believes that, for purposes of these

models, it is reasonable to assume that

populations are randomly distributed

within a single habitat type.

Comment: Several commenters noted

that the proposed wildlife mortality

model assumed that a wildlife species

redistributes itself uniformly over its

habitat each and every day. The

commenters thought this assumption

was not justifiable and would tend to

overstate wildlife mortality.

Response: The Department believes

that, for purposes of these models, it is

reasonable to assume that a wildlife

species redistributes itself uniformly

over its habitat each day. Habitat area

within the models is of a size on the

order of an individual’s actual home

range. Each individual does tend to
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20589

cover its home range each day, either for

feeding or territorial purposes. Thus,

populations do redistribute themselves

daily.

Comment: A commenter noted that

the models’ assumption that the density

of a species in its designated habitat is

constant throughout a given province

could result in overestimates of actual

mortalities for those provinces with

multiple grids.

Response: The Department does not

believe that this assumption leads to

overestimates for provinces with

multiple grids. The biological database

assigns the densities of species on all

appropriate designated habitats

regardless of the number of grids

contained in the province. However,

losses occurring in one grid are not

distributed across grid boundaries and,

thus would not overestimate losses.

Comment: A commenter thought the

NRDAM/GLE technical document

should specify the time frame duration

for all assumptions about species

density.

Response: The model assumes that

species densities are uniform by season.

The abundance tables clearly specify

that density figures are provided on a

seasonal basis. See Tables III.3.17

through III.3.27 and III.3.40 through

III.3.50, Volume III of the NRDAM/GLE

technical document.

Comment: A commenter noted that

several of the groups of marine birds

and mammals used in the NRDAM/CME

could be eliminated, based on

documentation of relative lack of

vulnerability to oil spills.

Response: The Department

acknowledges that some groups of

marine birds and mammals are not as

sensitive as others to the effects of oil

spills. However, the model also

evaluates indirect effects (e.g., via the

food web) for both oil and chemical

spills, which could be significant in

certain scenarios.

Comment: One commenter stated that

the species contained in the NRDAM/

CME should be limited to those for

which reliable abundance data exist, or

those that are threatened or endangered.

Response: The NRDAM/CME is

limited to those species for which

reliable abundance estimates were

available. Section 6, Volume I of the

NRDAM/CME technical document

explains the criteria the Department

used to establish the estimates. The

Department included threatened or

endangered species where data were

available. However, in light of the

limited range of injuries and

compensable values considered by the

models, if injuries to these species are

significant, trustees should consider

using type B procedures instead of a

type A procedure.

Comment: One commenter addressed

species abundance in New York Harbor.

The commenter was unable to match the

species abundance data for New York

Harbor with that of the Erwin and

Korschger (1979) reference cited. The

commenter also stated that inaccuracies

in abundance data resulted from a

failure to adequately identify habitat

types.

Response: The Department has

rechecked the data and made revisions,

as appropriate, using the Erwin and

Korschger (1979) source and other more

recent sources. The results of the

retabulated data are contained in

Section 5, Volume IV of the NRDAM/

CME technical document.

The wildlife abundance data

contained in the databases are provincewide abundances and, thus, are

independent of the habitat grids and the

habitat types assigned to the grid cells.

Table 6.4, Volume I of the NRDAM/CME

technical document contains the areas

of habitat used for all calculations of

wildlife abundances. Further, the

habitat grids for New York Harbor have

been revised based on comments

submitted by the States of New York

and New Jersey.

Comment: Another commenter stated

that Great Lakes wildlife abundances

should be based on a more thorough

review of the literature and thought that

Burt (1976) was an inappropriate source

of data. The commenter recommended

that the models incorporate site-specific

data wherever they are available instead

of applying average values for several

provinces.

Response: The Department has

incorporated site-specific information

into each of the lake provinces. The

Department used Burt (1976) only if

more province-specific data were not

available. Public commenters supplied

no additional data on wildlife

abundances in the Great Lakes. Further,

the Department conducted a thorough

search for published and unpublished

data and located no additional sources

of data. When abundances were highly

variable among lake province-specific

sources of equal validity, the

Department averaged available data to

reduce the error associated with the

estimates. Professional judgment, based

on life history information for the

species in question, was used to

determine how available data would be

applied.

Comment: Some commenters

disagreed with the statement in the

proposed NRDAM/CME technical

document that oysters are one of the

most important species in southern

Maine and New Hampshire.

Response: The commenter appears to

have misinterpreted the data contained

in the proposed technical document.

The Department acknowledges that

NMFS does not list commercial oyster

fisheries in northern New England;

however, there is a small recreational

fishery for oysters. Thus, they are not

commercially important but do have

recreational significance.

Comment: One commenter asserted

that shrimp is by far the most significant

catch in South Carolina. The commenter

also thought that roughtail rays, orange

filefish, and scad were overly abundant

in the database relative to shrimp.

Response: The Department could not

find any Federal or State stock

assessments or biomass surveys for

shrimp, roughtail rays, orange filefish,

or scad in South Carolina. Therefore, the

Department based the abundance data

for these species on NMFS commercial

catch statistics. The NMFS catch data do

not support the statement that shrimp

are the most significant catch in South

Carolina. Shrimp are a significant part

of the inshore catch for many of the

reporting areas, but are not common in

offshore areas. The database includes all

species for which NMFS catch data

were available. Roughtail rays do form

a large percentage of the catch by

weight; however, they are not as

significant economically as shrimp and,

thus, are not as highly valued in the

model. Orange filefish and scad are not

major portions of the catch and the

model accurately reflects that.

Comment: One commenter questioned

why the NRDAM/CME did not include

lobster in New York Harbor.

Response: The Department could not

find any Federal or State stock

assessments or biomass surveys of

lobster in New York Harbor; therefore,

the Department relied on NMFS

commercial catch statistics. The NMFS

commercial catch statistics do not show

any catch for lobster in New York

Harbor.

Comment: One commenter sought

clarification of several aspects of the

discussion of young-of-the-year

modeling in the NRDAM/CME technical

document. The commenter questioned

the meaning of the term ‘‘stable

distribution;’’ the connection between

young-of-the-year and the adult stocks;

and the meaning of the term ‘‘monthly

mean,’’ since no monthly mean

abundances are present in the young-ofthe-year database.

Response: The term ‘‘stable’’ means

constant in time. The Department has

clarified the NRDAM/CME technical

document on this point. See Section
20590 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

4.3.2, Volume I of the NRDAM/CME

technical document. The Department

has also expanded the NRDAM/CME

technical document to explain the

connection between adult stock and

young-of-the-year. See Section 6.5,

Volume I of the NRDAM/CME technical

document. The Department has

modified the derivation of young-of-theyear abundance estimates so that such

abundances are estimated on a daily

basis for the first year of life and

averaged for each month. See Section

6.5, Volume I, and Section 3, Volume IV

of the NRDAM/CME technical

document.

Comment: One commenter questioned

how the NRDAM/CME could determine

the young-of-the-year surviving the first

year of life under equilibrium

conditions without knowing the first

year natural mortality rate.

Response: The NRDAM/CME

calculates the number of one-year-old

individuals needed to replace the fished

stock, assuming equilibrium

populations. Thus, the actual numbers

of eggs and larvae are not calculated or

needed. The model is calculating the

percentage of one-year-old animals lost

because of the spill.

Comment: Given that the abundance

of a species may be seasonal, one

commenter questioned how it was

possible that the natural mortality rate

and the fishing mortality rate are

constant for members of a species group

within and across years, as the equation

for young-of-the-year requires.

Response: The natural mortality rates

and the fishing mortality rates apply to

the species population (stock) regardless

of location and abundance. Stock

abundances apply on a province-wide

basis. The abundances in a specific

province may vary by season due to

migration of stock in and out of different

provinces. Therefore, there is no

inconsistency between using a constant

mortality rate over time and using

abundance figures that vary by season.

For further discussion, see Section 6.5,

Volume I of the NRDAM/CME technical

document.

Comment: One commenter thought

the young-of-the-year database in the

NRDAM/CME was incomplete, noting

that there are several species groups in

the adult database that are absent in the

young-of-the-year database.

Response: Certain species, such as

anadromous fish, do not spawn in

marine habitats. Thus, there may be

adults present in a given province

without young-of-the-year present.

Comment: One commenter questioned

whether forage fish production was

nonexistent outside of structured

habitats as assumed in the database for

California provinces 40 through 47.

Response: The NRDAM/CME does not

assume that forage fish production is

nonexistent outside of structured

habitats. The food web model includes

forage fish, in particular planktivorous

forage fish, in open water habitats.

Comment: One commenter questioned

the inclusion of goldfish as

representative herbivorous forage fish in

wetlands in the proposed NRDAM/GLE

technical document.

Response: The Department used

goldfish in the table to which the

commenter refers simply as an example,

because it is one of the few truly

herbivorous fish. Most forage fish

feeding on the bottom are omnivorous.

Comment: One commenter thought

the proposed NRDAM/CME technical

document was unclear how zooplankton

production was determined since no

zooplankton production values were

presented in the biological database.

Response: The NRDAM/CME

calculates zooplankton production

based on a percentage of phytoplankton

production. The technical document has

been clarified. See Section 4.4, Volume

I of the NRDAM/CME technical

document.

Comment: A commenter noted that

the rates of production for planktivorous

forage fish were not provided in the

NRDAM/CME biological database and

questioned how primary production for

these fish was calculated.

Response: The NRDAM/CME

calculates planktivorous forage fish

production based on a percentage of

zooplankton production. The technical

document has been clarified. See

Section 4.4, Volume I of the NRDAM/

CME technical document.

Comment: One of the independent

technical reviewers questioned why

several bait fish species were not

included in the models.

Response: The Department did not

include such species because it could

find no quantitative data for such

species.

G. Toxicity and Mortality

Comment: Some of the independent

technical reviewers stated that the

biological effects submodel was logical

and well conceived for assessing the

effects of minor spills. However, other

commenters asserted that the submodel

suffered from an overall lack of

supporting data and questioned the

methods used for calculation of

mortality and toxicity data. One

commenter noted that bioassay studies

measuring the lethality of oil and

petroleum mixtures directly were

preferable to the oil toxicity

assumptions used in the models and

thought such information must surely

be available. Another commenter

asserted that laboratory bioassays

overestimate metals toxicity and that the

Department should consult EPA’s Water

Effects Ratio studies on binding capacity

in natural waters. A few commenters

thought that the models’ treatment of

metals speciation was overly simplistic.

Another commenter maintained that the

proposed toxicity values were too high

compared with EPA water quality

criteria. Further, the commenter

suggested the Department refer to EPA

sediment quality criteria for benthic

organisms.

Response: The Department believes

that the biological effects submodel

incorporates the best available mortality

and toxicity data. The Department has

not been able to locate bioassay data on

the toxicity of hydrocarbon products

that have been developed under

carefully controlled conditions, with

constant aromatic concentrations in the

water. Also, oil and petroleum products

are highly variable in their percent

composition and bioassay results. Very

few studies have addressed oil toxicity

and, therefore, the Department has not

used direct bioassay data on oils in the

models. See Section 4.2.3, Volume I of

the NRDAM/CME and NRDAM/GLE

technical documents.

Laboratory bioassays more closely

correspond to dissolved metal

concentration toxicity than total metal

concentration in the water. The models

estimate dissolved metal concentrations,

and these are the concentrations

assumed to be causing the injuries.

Thus, the models address metal

speciation to the extent possible,

without incorporating a complex

speciation model. Further, even such a

complex speciation model could not be

coupled to appropriate toxicity data at

the present time, as is well noted in EPA

and other literature.

EPA’s water quality criteria would not

be an appropriate basis for the models’

toxicity calculations. The toxicity data

in the models are mean values for acute

response. Water quality criteria are

designed to be lower than any

concentration found to have either an

acute or chronic response for even the

most sensitive species. Thus, the water

quality criteria should be lower than the

models’ toxicity data. EPA sediment

quality criteria are evaluated in Section

4.2.1, Volume I of the NRDAM/CME and

NRDAM/GLE technical documents.

Comment: One commenter provided a

highly technical review of the proposed

toxicity model. The commenter noted

that it was the commonly accepted

toxicity model currently used in
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20591

environmental toxicology. The

commenter encouraged the Department

to apply chemical- and species-specific

values to the alpha and gamma terms in

the toxicity algorithm.

Response: The Department

appreciates the in-depth review of the

toxicity model provided by the

commenter; however, insufficient data

exist at this time to make the

recommended changes. To the extent

possible, the Department has used

gamma values that are chemical-specific

and alpha values that vary by class of

chemicals. See Section 4.2.1, Volume I

of the NRDAM/CME and NRDAM/GLE

technical documents.

Comment: One commenter questioned

the accuracy of the toxicity calculations

of the proposed NRDAM/GLE,

particularly with regard to releases of

metals. The commenter provided

information on a series of test cases in

the Niagara River that the commenter

ran using the proposed NRDAM/GLE.

Response: Based on the information

provided, the Department believes the

test cases run by the commenter may

not provide an appropriate basis for

evaluating the NRDAM/GLE. The

NRDAM/GLE was not designed to

address multiple releases from various

sources over a number of years. It

appears that the commenter may have

run the cases with the accumulated

mass of contaminants as if that mass

had resulted from single event spills of

short duration. Also, the model was not

designed to evaluate long-term chronic

exposures to hazardous substances.

The Department does agree, however,

that pure metals are not correctly

modeled by the NRDAM/CME and

NRDAM/GLE. The toxicity data for

these metals are based on bioassay

studies that measured the dissolved

metal ion concentrations in water. Such

toxicity data are not representative of

the chemical state of the metal that

would occur under natural

environmental conditions. As a result,

the Department has deleted all pure

metals from the chemical databases.

Comment: Some commenters,

including one of the independent

technical reviewers, expressed concern

about the models’ failure to account for

the additive toxicity of aromatics in oils.

Response: The Department has

modified the NRDAM/CME and

NRDAM/GLE to include an additive

toxicity model that accounts for the

combined lethality of similar acting

aromatics in oils. The Department used

the information identified by one of the

commenters to construct this additive

toxicity model. See Section 4.2, Volume

I of the NRDAM/CME and NRDAM/GLE

technical documents for the specific

algorithm used and further clarification

of the changes made.

Comment: Several commenters noted

examples, primarily for metals, where

the proposed NRDAM/CME used

toxicity thresholds that were lower than

naturally occurring water solubilities.

The commenters suggested these errors

were due to the Department’s

inappropriate use of freshwater toxicity

data in saltwater environments.

Response: Comparison of the salt- and

freshwater databases for those chemicals

where data existed showed no

significant differences in toxicity values

given the variability of such data.

However, the Department has deleted

those chemicals where a difference

would be expected (i.e., those making

up salinity such as sodium).

The toxic thresholds in the models are

only used as switches to end the

calculations of the physical fates

submodel. When the physical fates

submodel determines that

concentrations are below this level in all

locations, it stops running. The

threshold is the concentration that

would cause one percent mortality at 30

degrees Celsius after 96 or more hours

of exposure for the most sensitive

species group. The biological effects

submodel calculates the actual mortality

for each species group based on

duration of exposure and temperature.

The proposed technical documents

contained an incorrect list of the toxic

thresholds actually used by the models.

The documents have been corrected.

See Table III.2.1, Volume III of the

NRDAM/CME and NRDAM/GLE

technical documents.

The toxicity data in the database,

including the threshold values, apply to

dissolved concentrations, not total

concentrations. For chemicals that are

highly partitioned, such as metals and

nonpolar organics, the dissolved

concentrations will be a small fraction

of the total. The physical fates submodel

partitions chemicals in both the water

column and the sediments. Only

dissolved chemical in the water column

or in the sediment pore water causes

toxicity in the models. Thus, the

toxicity values should not be compared

to total concentrations in water, but

rather to the dissolved portion only.

This accounts for the discrepancies

perceived by the commenter when

comparing thresholds to total metal

background concentrations. The

Department has eliminated all

chemicals with a solubility below the

toxic threshold.

Comment: One of the independent

technical reviewers thought that the use

of toxicity values based on acute

toxicity laboratory tests could

underestimate toxic effects, because in

acute tests involving up to 96 hours of

exposure, animals are typically not fed.

Thus effects result from water-borne

exposure only. The technical reviewer

concluded that the models may be

inappropriate for spills of hydrophobic

organic compounds where most of the

exposure would be through

contaminated food.

Response: The Department agrees that

the models may not fully capture the

effects of a spill that contaminates food

sources. The Department has revised the

technical documents to clarify this

point. See Section 4.2.1, Volume I of the

NRDAM/CME and NRDAM/GLE

technical documents.

Comment: One of the independent

technical reviewers thought that the

models should account for the

incremental effects of spills on existing

levels of contamination.

Response: The Department did

consider inclusion of background

contamination data in the models.

However, data sources were insufficient

to include such information for the

entire area covered by the models. As a

practical matter, background

contamination present at the spill site

before a spill would lower the threshold

for effects by the spill. Thus, not

including background contamination in

the models is likely to underestimate

injuries. However, the Department

believes that in cases where background

contamination is significant but the cost

of using type B procedures is not

reasonable, trustees should still have the

option of using a type A procedure.

Comment: Commenters suggested that

rather than use average exposure

concentrations in the plume, the models

should evaluate mortalities that accrue

from the actual cumulative exposure.

One of the independent technical

reviewers thought that it was not

meaningful to estimate fractions of

animals killed and recommended that

the models round up fractional

mortalities to total animals killed.

Response: Inadequate data currently

exist to estimate effects of cumulative

exposure. Further, the computational

complexities and the potential size of

the internal, intermediate data files are

effectively beyond the capacity of

currently available PCs. Instead, the

biological effects submodel performs

multiple iterative runs, using different

randomized algorithms, and then

averages the results of these runs to

avoid anomalous model outputs and

increase reliability. See Section 4.3.1,

Volume I of the NRDAM/CME and

NRDAM/GLE technical documents.

The model is intended to generate

valid mortality estimates for portions of
20592 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

populations rather than discrete deaths

of individual animals. Therefore,

fractional mortality figures are

appropriate.

Comment: One commenter thought

the portions of the NRDAM/CME and

NRDAM/GLE technical documents

pertaining to the use of particles to

represent biological populations were

unclear. The commenter sought

clarification of how the models operate

when the particles hit a physical

boundary within the models. The

commenter also sought clarification of

the fate of particles and their exposure

history during a change of seasons. The

commenter believed there should be

exposure memory for particles

representing those species whose

density is constant across seasons. The

commenter further supported the use of

multiple iterative runs to minimize the

variability error caused by using a finite

number of particles to represent a

population and by limiting particle

movements on a daily basis.

Response: Particles may be

transported out of a grid at the

downstream edge and ‘‘created’’ as

previously unexposed particles at the

upstream edge. Particles intersecting

land are reflected back into the water.

At the change in seasons, the models

assume that new individuals are present

(at pre-spill abundances) and do not

carry over the exposure history from the

past season. The past season’s injuries

are tabulated and the exposure history

for the new season is set at zero.

Therefore, in a case where exposure

extends across the seasonal boundary,

the time of exposure would be

underestimated. The technical

documents have been clarified on these

points. See Section 4.3, Volume I of the

NRDAM/CME and NRDAM/GLE

technical documents. The Department

agrees that multiple runs of the same

scenario will give a better prediction of

damages than a single run. Thus the

models’ internal procedures average

multiple runs to arrive at a damage

figure.

Comment: Several commenters

generally criticized the proposed

models’ wildlife mortality calculations.

Some commenters maintained that the

models fail to adequately distinguish

among effects of different types of

compounds and questioned the

application of wildlife mortality

probabilities to substances other than

crude oil since the only supporting data

sources were for crude oil.

Response: The Department considers

the wildlife mortality model to be

reasonable, scientifically justified and

consistent with experience in actual

spill events. The probabilities of

wildlife mortality used by the models

are based on data obtained from

observations of real spills. Some

modifications have been made to the

probability values based on more recent

information.

The Department acknowledges that

the supporting data sources for wildlife

mortality do address crude oil.

However, the Department believes that

the models adequately account for the

differences between crude oil and other

petroleum products by calculating

wildlife exposure dose based on the oil

thickness and slick size. The mortality

threshold is based on the exposure dose

that is sufficient to cause an observable

effect in experimental studies. If the

exposure level exceeds the threshold,

then wildlife mortality is assumed. For

example, petroleum products that

spread to sheen quickly, entrain, and/or

evaporate have much less effect on

wildlife in the models than thick, longlasting oils, such as crude oil. Thus, the

models account for differences among

hydrocarbon-based oils and products

through the physical fates submodel and

the exposure algorithm. This algorithm

is further explained in Section 4.3.4,

Volume I of the NRDAM/CME and

NRDAM/GLE technical documents.

Comment: Some commenters

contended that no data were available to

support mortality rates for raptors.

Commenters also questioned the

extrapolation of sea otter mortality

probabilities to polar bears.

Response: The Department considers

the eagle mortality rates to be

appropriate for raptors in general.

Mortality of eagles and other raptors as

calculated by the models generally

results from contact with slicks in

shallow waters and along shorelines,

and both eagles and other raptors

occupy such areas to similar degrees.

The eagle mortality rates used in the

models are also supported by evidence

from the Exxon Valdez spill. Further,

osprey behave very much like eagles.

Thus, the Department believes it is

reasonable to use the same mortality

rate for eagles and osprey.

The Department recognizes that no

explicit data are available on the

probability of polar bears dying from

spills. However, the Department

believes that it is appropriate to use the

same probability for all furbearers

because the mechanisms of exposure

and toxicity, namely ingestion of oil

through grooming, are similar.

Comment: One commenter thought

that the NRDAM/GLE should use a 90

to 95 percent mortality rate for ducks

contacting heavy oil, as the proposed

NRDAM/CME did.

Response: The Department has

modified the NRDAM/GLE to include

duck mortality rates that are consistent

with those in the NRDAM/CME. Based

on recent information, the Department

has incorporated a 99 percent mortality

rate in both models for those ducks that

are exposed to a spill over the threshold

dose. See Section 4.3.4, Volume I of the

NRDAM/GLE technical document.

Comment: Commenters noted an

apparent lack of correspondence

between numbers of marine birds the

models estimated to be killed, and

numbers killed based on actual wildlife

recoveries and detailed damage

assessments. One commenter believed

that the mortality counts for birds

impacted by oil spills in Florida

appeared low in almost all cases.

Commenters suggested an alternative

hindcast model for wildlife mortality

estimation that was used for the T/V

Puerto Rican, Apex Houston, Nestucca,

and Exxon Valdez oil spills.

Response: The Department believes

that the apparently low mortalities

observed by the commenter were due to

the low abundance data for certain bird

species contained in the proposed

biological database for the Florida coast.

The Department has revised the wildlife

database for the Florida coast based on

additional information provided by

commenters. Model runs conducted

with the revised wildlife abundance

database no longer reveal large

discrepancies. See Section 5, Volume IV

of the NRDAM/CME technical

document.

Also, the Department has revised the

probability of mortality for aerial divers

using hindcasts, as suggested. See

Section 4.3.4, Volume I of the NRDAM/

CME technical document.

Comment: Several commenters,

including one of the independent

technical reviewers, generally

questioned the oil mortality

probabilities and suggested that they be

calibrated to data from actual spills,

noting that the wildlife mortality

probabilities in the proposed models

were inconsistent with experience in

the Exxon Valdez spill.

Response: The mortality probabilities

included in the models are based in part

on data from actual spills. Very little

data exist on the natural resource effects

of small spills of the type addressed by

the type A models. Therefore, it is

impossible to determine the need for

calibration. Nonetheless, the

Department did consider data on

physical fates and biological effects

collected after the Exxon Valdez spill

when evaluating the NRDAM/CME’s

mortality predictions. Bird and marine

mammal injuries estimated by the
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20593

model provide reasonable agreement

with estimated kills caused by the spill.

Also, the commenters may not have

correctly interpreted how the model

calculates wildlife mortality. The

commenters inferred that the wildlife

mortality probabilities are multiplied

times all animals at risk, and include

populations for all of the northern Gulf

of Alaska in the total population at risk.

Instead, the model only multiplies the

probabilities times the animals actually

encountering oil and receiving a dose

above the threshold value. Thus, the

population ‘‘at risk’’ in this sense is

orders of magnitude lower than the

commenter’s suggested value.

Comment: Several commenters

asserted that the models overestimate

wildlife injuries by failing to account for

weathering of oil, the effect of

temperature, and the fact that light

products like gasoline and other floating

chemicals would be readily washed

from the coats of furbearers.

Response: The physical fates

submodel does account for weathering.

Evaporation, degradation, and

entrainment reduce the area and

thickness of slicks, which in turn

reduces the frequency with which

wildlife will be exposed to oil doses

large enough to induce effects. See

Section 3.5, Volume I of the NRDAM/

CME and NRDAM/GLE technical

documents. For example, extremely

volatile compounds evaporate so

quickly that their surface slicks have

essentially no effect on wildlife.

The Department does not think that

temperature is likely to have a

significant effect on mortality rates.

While one effect of oiling is a decrease

in thermal conductance of fur and

feathers, it is generally thought that the

predominant toxic effects result from

ingestion of oil during grooming. See

Section 4.3.4, Volume I of the NRDAM/

CME technical document. Also, animals

are adapted to the climate in which they

live. Thus, a tropical species suffers

from hypothermia at a higher

temperature than subpolar species.

Finally, the light products and

chemicals contained in crude oil are

widely recognized to be the more toxic

components. The light products and

chemicals are hydrophobic, and so

would not be washed from fur by

seawater. Given the same dose, in terms

of mass of hydrocarbons, these products

are expected to have similar effects to

crude oils.

Comment: One commenter thought

that the proposed 10 percent mortality

rate for terrestrial mammals was too

high.

Response: The Department agrees that

the proposed mortality rate of 10

percent was too high and has reduced

it to 0.1 percent. The Department

considers this revised rate to be

reasonable as compared to the mortality

rate for seals. The NRDAM/CME

assumes a seal mortality rate of 1.0

percent based on hindcast projections

using Exxon Valdez data. Seals

continuously inhabit open waters and

shorelines, whereas terrestrial wildlife

inhabit shorelines only a portion of the

time. Therefore, terrestrial mammals

would be expected to have lower rates

of encountering spills and, thus, lower

mortality rates.

Comment: Commenters suggested the

models grossly overestimate fish

mortality from oil spills by

overestimating dissolved hydrocarbon

concentrations. These commenters

particularly took issue with the

Department’s assumption that total

aromatic hydrocarbon content of a spill

remains the same by percentage before

and after the spill. These commenters

cited studies showing that weathering

results in little of the hydrocarbon

content entering the water column.

Response: The Department does not

think that the models overestimate fish

mortality resulting from oil spills.

Aromatics in oils are known to cause

the most acute toxicity. See Section

4.2.3, Volume I of the NRDAM/CME and

NRDAM/GLE technical documents. The

physical fates submodel separately

tracks dissolved aromatics of two

molecular weight size classes: (1)

monoaromatic benzenes and (2)

diaromatic compounds. These aromatics

do volatilize rapidly in the models.

Thus, relatively little of these aromatics

end up in the water column and cause

toxicity. See Section 3.5, Volume I of

the NRDAM/CME and NRDAM/GLE

technical documents.

Also, the models do not assume that

the percent composition of total

aromatic hydrocarbons remains constant

in the spilled substance. The

Department has clarified the text of the

technical documents on this point. See

Section 4.2.3, Volume I of the NRDAM/

CME and NRDAM/GLE technical

documents.

Comment: Commenters asserted that

it is too simplistic to use a mean LC50

(the concentration at which 50 percent

of test organisms die within a defined

time period) for the whole taxonomic

class of fish or for all plants, algae, or

angiosperms. Further, commenters

maintained that the Department failed

to provide information sufficient to

evaluate the statistical relationships

involved.

Response: The NRDAM/CME and

NRDAM/GLE technical documents

contain detailed descriptions of the

process the Department used to derive

average toxicity parameters. Researchers

have found that the LC50 for one

species is a reasonable predictor of

toxicity for other species within the

same family and that, in many cases,

cross-family correlations are also

significant. See Sections 4 and 7,

Volume I of the NRDAM/CME and

NRDAM/GLE technical documents.

Also, the administrative record for this

rulemaking includes additional material

on the derivation of average toxicity

parameters.

Available information is insufficient

to disaggregate further the toxicity

values used in the models.

Disaggregation of the few data available

would increase the error in the model

result because of the uncertainties

associated with individual data points.

For plants, algae, or angiosperms,

available data in EPA’s AQUIRE

database support the use of a mean

LC50 value. There are insufficient data

to quantify differing values by plant

group. The Department does not believe

that use of more specific plant values

would significantly improve the

reliability of the model damage figure

because the model damage figures are

not sensitive to the value assumed,

within the range of observed data for a

given chemical.

Comment: A few commenters

generally criticized the Department’s

approach to assessing fish mortality

from toxicity data using statistically

averaged values, asserting that

information necessary to review the

adequacy of such an approach was not

included in the proposed technical

documents. One of the commenters

noted apparent inconsistencies between

the values used in the models and the

values in the AQUIRE database. Another

commenter asserted that unless the

Department could demonstrate that the

oil toxicity algorithms in the revised

NRDAM/CME were more accurate than

those in the original NRDAM/CME

issued in 1987, the Department should

return to the original algorithms.

Response: The Department believes it

has provided sufficient information and

opportunity to review the approaches

used to calculate fish mortality and to

derive the toxicity data contained in the

databases. Section 4, Volume I of the

NRDAM/CME and NRDAM/GLE

technical documents explains how the

models calculate fish mortality. Section

2, Volume III of the NRDAM/CME and

NRDAM/GLE technical documents

provides toxicity values for each

substance contained in the chemical

databases and the source of information

used to derive those values. Due to the

volume of material, the Department has
20594 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

not included in the technical documents

all of the raw data and statistical

analyses that were compiled for each

toxicity value. However, the sources of

the raw data, such as AQUIRE, are

available to the public. Also the

methods used to derive the statistically

averaged toxicity values are consistent

with those commonly used in aquatic

toxicology. The toxicity values used in

the model are based on all literature in

the AQUIRE database as of November

1991. The AQUIRE database has not

been updated since that time. The

commenter appears to have reviewed

only a limited range of data in the

AQUIRE database.

Finally, the Department believes that

the revised NRDAM/CME is an

improvement over the original NRDAM/

CME and more accurately calculates oil

toxicity. The technical documents

explain all oil toxicity values used in

the models. See Section 4.2.3, Volume

I, and Section 2, Volume III of the

NRDAM/CME and NRDAM/GLE

technical documents. The toxicity

parameters are for dissolved aromatic

hydrocarbons of less than 200 molecular

weight, which is what the models

calculate as the toxic material.

Literature estimates are for whole oil,

total petroleum hydrocarbons, or water

soluble fractions, and thus are

inapplicable to and higher than those

for the dissolved low molecular weight

fraction.

Comment: One commenter noted that

the susceptibility of developing fish

eggs and larvae to toxic substances

changes over time and sought

clarification whether the models

account for seasonal variations in

toxicity.

Response: The Department recognizes

that the susceptibility of fish eggs and

larvae to toxic substances may change

with age. However, the Department does

not think that sufficient research data

have been compiled to quantify a

change in toxicity by age of eggs and

larvae for all the species groups and

chemical substances contained in the

chemical database. Therefore, the

models have not been revised to account

for this potential effect.

Comment: Some commenters,

including one of the independent

technical reviewers, criticized the

models for failing to account for the

effects of avoidance of a spill by fish.

Response: The Department

acknowledges that some portion of fish

populations may avoid spills of some

types of chemicals. However, the

Department was unable to identify

adequate quantitative data on this

phenomenon to include it in the models

at this time.

Comment: One of the independent

technical reviewers thought the

NRDAM/CME should account for the

fact that fish and macroinvertebrates

may be exposed to intertidal

contamination when the tide is in.

Response: The model does account for

tidal inundation in its calculation of the

water column plume. Contamination in

the water may move into intertidal areas

when water is present over them. When

the tide goes out, the plume is

transported out as well.

Comment: One of the independent

technical reviewers thought the fish

swimming speeds used in the proposed

models were extremely low.

Response: The Department believes

that the swimming speeds incorporated

in the models are appropriate for the

time step involved. The models use

these speeds as distance moved in a

single direction in an individual time

step. Direction is randomized, so that

after many time steps, motion is

random. The rates are low because of

the time step used. Otherwise, there is

too much migration of fish in the

models. For further discussion, see

Section 4.3.1, Volume I of the NRDAM/

CME and NRDAM/GLE technical

documents.

Comment: One commenter questioned

the accuracy of the statement in the

proposed NRDAM/GLE technical

document that short duration

disturbances of biota are not evaluated

in light of the fact that the model

specifically focuses on acute injury.

Response: The statement in the

technical document to which the

commenter refers simply addresses the

model assumption that seasonal

biological abundances do not change for

reasons other than the spill. See Section

4.1.2, Volume I of the NRDAM/GLE

technical document.

Comment: One commenter stated that

the Department had made an

unsubstantiated assumption that, for

wildlife, death of parent animals will

necessarily lead to death of immature

animals. However, other commenters

stated that, according to the equations in

the proposed technical documents, the

models fail to account for lost future

harvest of young that are killed as a

result of the death of their parents. A

few commenters thought the models

assumed that the spill occurred at the

time of fledging and that the time of

fledging is constant for all species. Some

commenters also thought that the

hatching and fledging times presented

in the database were excessive.

Response: The models assume that if

adult birds or mammals are killed while

their young are dependent upon them,

then the young will be lost as well. See

Section 4.5.2, Volume I of the NRDAM/

CME and NRDAM/GLE technical

documents. The models do not assume

that the spill occurs at the time of

fledging or that the time of fledging is

constant for all species. The wildlife life

history parameters used by the models

include the age (in months) at which

young are fledged or weaned, not the

month of the year in which they are

fledged or weaned. The fledging and

weaning ages in the database are the

ages at which young become

independent. See Section 4, Volume IV

of the NRDAM/CME technical

document, and Section 3.6, Volume III

of the NRDAM/GLE technical

document.

A substantial volume of literature

addresses the parental care of young

birds and mammals and the inability of

those young to survive without parents.

See Section 4, Volume IV of the

NRDAM/CME technical document, and

Section 3.8.4, Volume III of the

NRDAM/GLE technical document. The

Department believes it has provided

ample documentation to substantiate

that the death of parent animals does

result in the death of young that are

dependent on them.

H. Loss of Production

Comment: One of the independent

technical reviewers stated that direct

oiling can kill seagrass and thereby

reduce habitat function. The technical

reviewer suggested that the models

account for the effect of oiling on

submerged macrophytes such as

seagrass and kelp.

Response: The NRDAM/CME

calculates the sublethal loss of

production and the acute lethal effects

to subtidal seagrasses and other

submerged macrophytes exposed to

concentrations of dissolved oil in the

water. However, evidence of oil coating

and smothering macrophytes that are

under water or in floating beds, does not

appear to be available. The Department

does not consider smothering of

subtidal seagrass to be likely given that

oil slicks float on the water surface and

wave action would flush the oil from

floating beds. Therefore, the Department

has not included the coating and

smothering of subtidal macrophytes as

an injury calculated by the model.

Intertidal seagrass habitats have been

added to the NRDAM/CME as a new

habitat type. The Department recognizes

that intertidal seagrass can be coated by

oil and smothered. Research studies

have shown saltmarsh plant mortalities

to occur from exposure to oil

thicknesses of 14 millimeters. As a

result, oiling of intertidal seagrass beds

over a threshold thickness of 14
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20595

millimeters is considered lethal to

seagrass, which is consistent with the

model’s treatment of oiling effects on

other intertidal habitat types. See

Section 4.3.3.2, Volume I of the

NRDAM/CME technical document.

Comment: One commenter thought

that the proposed method of estimating

post-spill recovery of macrophyte

primary production was adequate for

the purposes of the NRDAM/CME.

However, the commenter suggested that

the Department consider adjusting the

sigmoidal function used to estimate the

rate of biomass production so that the

maximum rate of production occurs at

one-half of the pre-spill biomass level.

Response: The Department

acknowledges the limitations of

available data to specifically define the

shape of the recovery curve for

macrophyte production. However, the

model results are not sensitive to the

specific shape of the recovery curve;

therefore, further effort to refine the

curve is not likely to result in

significantly improved reliability.

Comment: A few commenters,

including one of the independent

technical reviewers, thought the models

should consider the effects of

compensatory growth (i.e., enhanced

production due to the removal of interand intra-species density-dependent

growth-limiting factors). These

commenters stated that the models

would overestimate production losses

unless compensatory growth were

considered. The commenter also

suggested that, for lower trophic levels,

the models should use the upper 75th

percentile of the available LC50 or EC50

(i.e., the concentration at which growth

is reduced by 50 percent) values rather

than the mean of the LC50 and EC50

values.

Response: The Department

acknowledges that compensatory

growth is not addressed within the

models. However, the Department does

not believe that production losses are

overestimated as a result. For the small

spills for which the models were

designed, density-dependent growth

and survival effects are likely to be

insignificant. Further, densitydependent effects of large changes in

fish population sizes have been difficult

to quantify because of large natural

variations and other ecological forces.

The known disturbances that enhance

productivity in ecosystems are natural

events to which the ecosystem adapts

rather than hazardous substance spills.

The selection of only the upper 75th

percentile of the LC50 and EC50 data

would arbitrarily exclude toxicity data

that may be representative of all

sensitive and nonsensitive organisms in

the field. Instead, the use of only the

higher LC50 data would likely be

representative of only the direct

mortality to nonsensitive organisms.

Comment: One of the independent

technical reviewers recommended that

the Department adopt a habitat-based

approach to calculating the loss of

production. Under this approach, each

grid would have an associated biomass

per unit area, and if that grid were oiled,

an assumed percent of yield would be

lost.

Response: The models do use a

habitat-based approach in the

calculation of lost production. Each

contiguous grid cell of the same habitat

type within the grid has an associated

biomass per unit area. The models

calculate a percentage loss of biomass

for the defined habitat type based on

concentration and time of exposure.

Biomass losses are summed and

multiplied times the fishing mortality

rate within the habitat type to calculate

the lost yield. See Sections 4.3 and 6.2,

Volume I of the NRDAM/CME technical

document, and Sections 4.3 and 8.2.2,

Volume I of the NRDAM/GLE technical

document.

Comment: Several commenters stated

that the models rely on assumptions

about ecological and exposure processes

that are inconsistent with actual

environmental conditions and could

result in inflated damage estimates.

Some commenters thought that the

models inappropriately assume that

ecological communities are evenly

distributed both temporally and

spatially. Several commenters disagreed

with the model assumption that all

demersal young-of-the-year are attached

to the bottom and thought that this

assumption would overestimate injury.

Some commenters stated that the

assumption that the depth of

bioturbation is always 10 centimeters

would also lead to overestimates of

injuries. One of the independent

technical reviewers thought that the

models should account for vertical

migration.

Response: Ecosystems have the

resilience to adapt to a number of

unpredictable disturbances. Further,

most small spills do not appear to

significantly alter ecosystem structure or

the temporal distribution of

populations. The purpose of the models

is to evaluate effects of spills small

enough that they do not significantly

alter ecosystem structure and dynamics.

The Department believes it is reasonable

to assume stable temporal distributions

and that such an assumption is not

inconsistent with actual environmental

conditions during small spills.

Therefore, the models continue to

assume temporal distribution is

constant by season for fish and shellfish

and by month for young-of-the-year.

The models do not assume even

spatial distributions of ecological

communities. The abundance data

contained in the biological database

were developed assuming evenly

distributed species abundances within a

particular habitat and biological

province occupied by the species, and

within a given season or month. The

species abundance data are assigned to

the models’ biological computational

particles. Abundances of young-of-the

year change monthly between habitats,

provinces, and portions of the water

column (pelagic, demersal or benthic),

as appropriate to the species’ life

history. Therefore, the particles do not

represent abundances that are evenly

distributed spatially.

The Department acknowledges that a

small portion of demersal young-of-theyear are potentially carried by currents.

However, for the purposes of these

models, the Department believes it is

reasonable to assume that all demersal

young-of-the-year are attached to the

bottom. See Section 4.3.2, Volume I of

the NRDAM/CME and NRDAM/GLE

technical documents. If any demersal

young-of-the-year did in fact drift with

the current, they would likely be more

exposed to the released substance,

which would also be moving with the

current. Therefore, if the assumption

that all demersal young-of-the-year are

attached to the bottom is not reasonable

in a particular case, the models are

likely to underestimate rather than

overestimate damages.

Also, simulation of vertical migration

would require substantial additional

modeling. The Department does not

believe that adding such complexity

would substantially improve the

reliability of the final damage figure.

In some contaminated, and thus

ecologically stressed, habitats, the depth

of bioturbation may be less than 10

centimeters. However, for most regions

covered by the models, the Department

believes it is reasonable to assume a

depth of 10 centimeters, since most

estuarine and marine sediments are

relatively uncontaminated. Contrary to

the commenters’ assertion that this

assumption may cause an overestimate

in pore water concentrations in areas

where bioturbation is small, the dilution

of contaminants over the assumed depth

of 10 centimeters could underestimate

pore water concentrations and injuries.

Comment: Some of the commenters,

including one of the independent

technical reviewers, thought the food

web model was crude. For example, the

independent technical reviewer
20596 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

questioned the assumption that all biota

are equivalent as food sources. Another

commenter stated that the model

provided only a rough approximation of

upper trophic-level production losses

attributable to spill-related reductions in

primary productivity.

Response: The Department

acknowledges that the food web model

is generalized for all aquatic habitats,

but believes it is reasonable for the

purposes of the NRDAM/GLE and

NRDAM/CME. The food web model

provides a reliable approximation of

spill-related upper trophic-level

production losses due to lost primary

productivity. The Department believes

that development of a more

sophisticated, geographic-specific food

web model would not significantly

improve the reliability of the final

damage figure.

Comment: One of the independent

technical reviewers thought that the

consumption rate parameters contained

in the food web model should vary

seasonally.

Response: Seasonal changes in lower

trophic-level production rates and in

temperature already partially provide a

seasonal effect in the models. The

Department does not believe that further

refinement would significantly improve

the reliability of the final damage figure.

I. Catch and Bag Losses

Comment: Several commenters

addressed the methods used to translate

fish mortality and wildlife mortality

into reductions in catch and bag.

Commenters noted that a correct

translation was needed because

mortality is not a sufficient basis for

damages if it does not result in a

quantifiable reduction in the services

provided by the resources. Some

commenters thought the proposed

single-species approach to modeling

fishery complexes and ecosystems was

simplistic but adequate for the purposes

of the type A models. Other commenters

argued that predictions of catch and bag

losses were wholly unreliable and

resulted in inflated estimates of service

losses.

Some commenters stated that the

models sometimes predict a catch loss

that exceeds the prediction of total

mortality. These commenters asserted

that inaccurately high fishing rates in

the proposed NRDAM/GLE lead to the

estimation that 50 to 70 percent of some

fish species would be caught in a single

year. Commenters complained that lost

wildlife bag predictions failed to

account for regional differences. Some

commenters thought that failure to

consider hunting regulations would

inappropriately result in the calculation

of losses even when hunting is

prohibited. Commenters also criticized

the use of uniform annual hunting

mortality rates that do not assume any

particular underlying daily patterns that

would produce such rates.

Response: The type A models

calculate lost catch based on a standard

fisheries model. See Section 4.5.1,

Volume I of the NRDAM/CME and

NRDAM/GLE technical documents.

Fishing mortality is an instantaneous

rate, the coefficient of an exponential,

first-order ‘‘decay’’ curve. The nature of

this equation is that an instantaneous

fishing mortality rate of one corresponds

to an annual harvest of 63 percent of the

standing stock abundance present at the

beginning of the year. The models

account for growth of animals over the

year they are harvested. Thus, the

harvest may exceed the standing stock

biomass present at any given time if the

growth rate of the species is high. An

annual harvest rate of 63 percent of

standing stock abundance at the

beginning of the year is not equivalent

to a 63 percent catch of all the fish

species stock cumulatively available

throughout the year. The fishing

mortality rates assumed in the database

are based on best available fisheries

statistics estimated by NMFS and State

fisheries management agencies.

The models apply hunting mortality

rates to a population, i.e., a stock or

group of interbreeding animals. See

Section 4.5.3, Volume I of the NRDAM/

CME and NRDAM/GLE technical

documents. The hunting mortality rate

in the models is simply the probability

of being hunted successfully at some

time and place over one year of life.

Therefore, the models need not consider

exactly where or when the animals are

actually taken during a given year or

whether hunting seasons are open or

closed at the spill site. The Department

derived the hunting mortality rates from

tagging studies. A considerable amount

of literature shows that birds and

mammals have similar hunting

mortality rates per animal (or per 100

animals) throughout North American

populations due to migratory behavior

and biological limits on productivity.

See Section 4, Volume IV of the

NRDAM/CME technical document.

Therefore, the models use per-animal

rates that are justifiably constant in time

and space.

Comment: Some commenters thought

it was inconsistent for the models to

assume that a fish species may be

present or absent in certain seasons

while also assuming that fishing and

natural mortality rates are constant and

act continuously on the population

throughout the year.

Response: The models include fishing

and natural mortality rates that apply to

stocks, which may move seasonally. The

rates apply to the entire population of

fish within the provinces occupied by a

given stock no matter whether they are

present or absent from particular

locations at different times of the year.

Comment: One commenter thought

that the fish biomass figures used in the

calculation of predation rates should

reflect the entire stock, not just the

exploitable stock biomass.

Response: The models do, in fact, use

the total stock biomass in these

calculations.

Comment: A few commenters noted

that the yield model assumes that the

biomass of each fish species is

uniformly distributed over the entire

province in which it is found, while the

figures in the database reflect the actual

distribution of the stock. The

commenters further noted that if a

species did not extend throughout the

entire province, then this assumption

would lead to an overestimate of loss of

yield.

Response: The Department chose

province boundaries to minimize this

source of error in the models.

Additionally, there are three sub-areas

(habitats) within each province with

unique fishery biomasses. See Section

6.3, Volume I of the NRDAM/CME

technical document.

Comment: A few commenters raised

questions about the interplay between

the user-supplied information on

closures and the models’ spill-related

mortality predictions. The commenters

noted that the models do not adjust

fishing mortality rates when there is a

closure. Commenters suggested that

users be allowed to make such an

adjustment to avoid underestimating

recovery periods.

Response: The Department believes

the assumption of a constant fishing

mortality rate is reasonable for purposes

of calculating recovery periods after

minor spills. Only very large changes in

fishing would be measurable in the

population over the long term. For

minor releases, it is unlikely that

extended closures will occur.

Comment: One commenter questioned

the yield formulas in the proposed

NRDAM/CME technical document and

offered alternative formulas. The

commenter noted that the proposed

equations appeared to be missing the

final year’s contribution to yield.

Response: The Department has

reviewed the alternative formulas

offered by the commenter and has

concluded that they are more precise.

The Department has modified the final

versions of the models accordingly. The
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20597

models continue to calculate losses

through the last year after the spill

effects where killed individuals would

have lived and died naturally. The

Department has clarified the language of

the technical documents on this point.

See Section 4.5.1, Volume I of the

NRDAM/CME and NRDAM/GLE

technical documents.

J. Habitat Restoration

Comment: Several commenters

thought that the proposed methodology

for calculating habitat restoration costs

was so flawed that the Department

should eliminate such damages from the

models. These commenters identified

four major flaws in the methodology

that, taken together, render it invalid: (1)

The models’ acute toxic threshold is

unrealistically low, leading the models

to overestimate the size of the areas

needing restoration; (2) the models often

overestimate the time necessary for

natural recovery; (3) the models select

specific physical restoration measures

without regard to their feasibility; and

(4) the Department overestimated the

fixed costs for small spills.

Response: As discussed in more detail

below, the Department believes that the

methodology for calculating habitat

restoration costs is reliable. Therefore,

the Department has retained the

methodology in the final versions of the

NRDAM/CME and the NRDAM/GLE

subject to the revisions described in

Section VI.B of this preamble.

Comment: Several commenters said

the Department had failed to consider

adequately the feasibility or the costeffectiveness of the specific restoration

actions included in the models. For

example, commenters argued that

sediment capping in deep water is not

a proven technique and that the cost of

such capping is highly site-specific.

Therefore, these commenters thought

that deep-water capping should be

eliminated from the models.

Commenters also thought that the

Department had failed to substantiate its

claim that the types of habitat

restoration actions considered by the

models are in fact the most costeffective. Some commenters, including

one of the independent technical

reviewers, thought the Department had

unduly limited the range of restoration

actions the models consider, and should

have included off-site restoration,

partial rehabilitation, and other

mitigating actions.

Response: The Department has

concluded, based on an extensive

literature review, that all restoration

options considered by the models are

technically feasible. For additional

discussion see Sections 5 and 12,

Volume I of the NRDAM/CME technical

document, and Sections 5 and 9,

Volume I of the NRDAM/GLE technical

document.

Sediment capping in deep water is

technically possible. The models

calculate damages based on the cost of

capping only if toxicity in sediments of

an entire grid cell is so persistent that

recovery following capping would be

faster than natural recovery. The

Department believes that in such cases,

sediment capping is appropriate. The

Department has attempted to account

for site-specific factors relating to

offshore capping by including cost

figures that take into consideration the

different distances that equipment and

sediments must be transported.

The Department also carefully

evaluated a wide range of possible

habitat restoration actions, including

replacement of the affected resources

with other resources, acquisition of

equivalent resources, natural recovery,

and other technologies. Based on this

evaluation, the Department believes that

it has identified the most cost-effective

types of habitat restoration that can

reasonably be included in models of this

type.

With regard to off-site restoration, the

Department acknowledges that after

recovering damages through the use of

a type A procedure, trustees may well

decide that the recoveries are best spent

on off-site actions, such as the purchase

and enhancement of nearby property to

provide equivalent habitat to that lost.

However, the availability of nearby land

of the same habitat type as that injured,

the cost of any available land, and the

need for and feasibility of any actions to

make the land equivalent in quality to

that lost are all highly site-specific

factors. The Department does not

believe that adequate data are currently

available to include off-site restoration

among the list of restoration actions

evaluated by the models. With regard to

partial rehabilitation, the Department

has improved the resolution of the

NRDAM/CME by a factor of four, which

allows the restoration submodel to

consider restoration of much smaller

geographic areas.

Comment: One commenter noted that

techniques for reestablishing freshwater

macrophyte beds of wild celery have

been well demonstrated and should be

separately included in the NRDAM/

GLE.

Response: The NRDAM/GLE does

evaluate actions to restore wild celery

beds but does so through consideration

of a single type of restoration action for

all aquatic bed habitats. The Department

does not think the differences between

the techniques for restoring various

types of aquatic beds necessitate the

development of distinct per-unit

restoration costs for each type.

Comment: Several commenters said

that the models grossly overestimate the

size of the areas to be restored because

they use unrealistically low toxicity

thresholds. To illustrate this point,

commenters noted that the models

assign a toxicity threshold to cupric

chloride that is less than 1/40th its

normal concentration in saltwater.

These commenters argued that a spill of

cupric chloride would have to spread

over a huge area before it would

dissipate below the toxic threshold,

which would then necessitate

restoration over a similarly huge area.

Response: The toxicity thresholds

included in the models merely serve as

switches to end a model run. When the

physical fates submodel determines that

concentrations of the released substance

are below the threshold level for that

substance in all locations, it stops

running. The threshold is the

concentration that would cause one

percent mortality at 30 degrees Celsius

after 96 or more hours of exposure in

the most sensitive species group. When

calculating habitat restoration costs, the

restoration submodel will examine all

areas over which the spill has spread

but will only calculate the cost of active

restoration if it would result in lower

compensable value than natural

recovery. Compensable value is

generated only when there is mortality

or loss of production. The biological

effects submodel calculates mortality

and loss of production not on the basis

of the toxicity thresholds but rather on

the basis of mean LC50 and EC50

values. Therefore, the toxicity

thresholds do not determine the extent

of habitat restoration. Further, the

models will only include the cost of

active restoration in the final damage

figure if such active restoration passes

the cost-benefit test discussed below.

Comment: There were several

comments concerning the models’

predictions of recovery times. One of

the independent technical reviewers

suggested that the recovery times be

modified. Another commenter noted

that recovery times are very uncertain

and that relatively small adjustments

can have significant effects on estimates

of total losses. Several commenters said

the proposed restoration submodel

generally overestimated the time

required for natural recovery. Some

commenters stated that the NRDAM/

CME appeared to incorporate recovery

times for seagrass beds and coral reefs

that exceeded the literature values listed

in the proposed NRDAM/CME technical

document. Other commenters
20598 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

questioned the lack of data for saltmarsh

wetlands and mudflats and criticized

the Department’s use of identical

recovery times for mudflats and sandy

beaches.

Response: The Department believes

that the scientific literature supports the

recovery times for seagrass beds, coral

reefs, saltmarsh wetlands, and mudflats

contained in the NRDAM/CME. Further,

the recovery periods included in the

NRDAM/CME for seagrass beds and

coral reef are consistent with the

literature cited in the technical

document. See Section 4.3.3.2, Volume

I of the NRDAM/CME technical

document.

Comment: One commenter questioned

the Department’s assumption that

reproduction of fish and wildlife species

resumes normal levels as soon as

toxicity is no longer present.

Response: The Department recognizes

that substances may cause sublethal or

chronic injuries that affect reproduction

after concentrations have dropped

below acutely toxic levels. However, the

models do not attempt to address the

effects of such sublethal or chronic

injuries. If trustees believe such injuries

are likely to be significant, they should

consider conducting type B studies

instead of, or in addition to, a type A

procedure.

Comment: There were a few

comments about the inclusion of fixed

restoration costs in the models. Some

commenters, including some of the

independent technical reviewers,

thought that the fixed cost figure was

too low; other commenters thought it

was too high. One of the independent

technical reviewers thought different

fixed costs should be applied depending

on the type of habitat affected.

Response: Trustees who use a type A

procedure will have to develop a

restoration plan once they obtain

compensation for the natural resource

injuries. See 43 CFR 11.93(a). The

proposed models included a fixed cost

of $18,300 to cover restoration planning

costs. The Department recognizes that

the extent of the restoration planning

costs for each particular case may vary

dramatically. Such costs depend on

whether the trustees intend to

implement the restoration actions

chosen by the model or develop other

restoration actions. The costs also vary

depending on the complexity of the

selected restoration actions. In light of

the highly site-specific nature of

restoration planning costs, the

Department has chosen to eliminate

them from the models.

Nevertheless, § 11.15(a)(3) of the

regulations, which is not changed by

this rulemaking, allows trustees to

recover the reasonable and necessary

costs of an assessment. These costs

include ‘‘[a]dministrative costs and

expenses necessary for, and incidental

to * * * restoration, rehabilitation,

replacement, and/or acquisition of

equivalent resources planning.’’ 43 CFR

11.15(a)(3)(ii). Therefore, trustees who

use a type A procedure and wish to

recover restoration planning costs may

develop their own estimates of such

costs and include them as assessment

costs in the demand presented to the

PRPs under revised § 11.91(a).

Comment: One commenter was

generally concerned about the quality of

the Department’s information-gathering

efforts on habitat restoration techniques,

noting the lack of current references in

the technical documents. The

independent technical reviewers

recommended that the Department

update the per-unit restoration cost data

included in the models.

Response: NOAA conducted an

extensive literature search on natural

resource restoration while developing

guidance documents in connection with

its natural resource damage assessment

rulemaking under OPA. The Department

has updated the per-unit restoration

costs included in the models based on

information compiled through this

NOAA effort as well as other recent

information. Also, as discussed below,

the Department has revised the habitat

restoration actions evaluated for

structured habitats (i.e., wetlands,

seagrass, macroalgal, coral, mollusk, and

reef).

Comment: A few commenters thought

that the costs of upland disposal of

sediments in the proposed NRDAM/GLE

inappropriately failed to factor in longterm operation and maintenance.

Response: The model includes the

per-unit costs that a commercial facility

would charge to accept sediment for

disposal. These costs are one-time costs

charged by the commercial facility and,

thus, should include the facility’s

anticipated long-term operation and

maintenance costs. Trustees would not

incur any additional long-term costs.

Comment: Some of the independent

technical reviewers thought that the

NRDAM/CME incorrectly assumed that

seagrass replanting and oyster reef

seeding would entail destruction and

subsequent reestablishment of the entire

habitat. These technical reviewers also

thought this assumption would produce

a bias against invoking habitat

restoration because habitat restoration of

this nature will generally result in

compensable value in excess of that

which would occur under natural

recovery.

Response: The Department has

reevaluated the habitat restoration

actions included for seagrass beds,

invertebrate reefs, and other structured

habitats and decided that in certain

circumstances it would be technically

feasible and more cost-effective to

perform restoration actions that are less

invasive than replacement of substrate.

Therefore, the Department has revised

the NRDAM/CME to include two

potential restoration actions for such

habitats. Where the sediments are

sufficiently contaminated, the

restoration submodel evaluates substrate

replacement or capping followed by

replanting or reseeding of the vegetation

or invertebrate structure. Where

sediments are not contaminated but

mortality of the structural habitat has

occurred, the submodel evaluates

replanting or reseeding alone. The

submodel evaluates each affected grid

cell. See Section 12.2, Volume I of the

NRDAM/CME technical document.

Comment: One commenter thought

that the Department had inappropriately

based freshwater wetland restoration

alternatives for hazardous substance

releases on oil-related experiences.

Response: The Department did not

base freshwater wetland restoration for

hazardous substance releases on data

relating to oil spills. In fact, data on

freshwater wetland restoration arises

almost entirely out of non-oil

experiences. See Section 5.7, Volume I

of the NRDAM/GLE technical

document.

Comment: One commenter noted that

removal and replacement of soils and

vegetation is subject to failure and, even

if ‘‘successful,’’ results in different

habitat.

Response: The Department agrees that

removal of substrate and replanting can

result in failures and the emergence of

different habitats. The Department

developed recovery rates and per-unit

restoration costs that account for such

risks.

Comment: One commenter objected to

the inclusion of washing and steam

cleaning as restoration alternatives,

noting that such actions caused injury

during the Exxon Valdez response.

Response: The Department has

retained washing and steam cleaning as

a potential shoreline habitat restoration

alternative in the NRDAM/CME. The

Department agrees that washing and

steam cleaning cause injury but believes

that inclusion of such alternatives in the

model is appropriate subject to the

decision criteria used by the models.

When the model evaluates these

alternatives, it assumes that the actions

will destroy the habitat. The model will

only select these alternatives if,
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20599

notwithstanding their deleterious

effects, they nonetheless result in lower

compensable value than natural

recovery. In coastal and marine

environments, the tidal flux creates a

distinct shoreline habitat that is not

present in the Great Lakes. Therefore,

the NRDAM/GLE does not include

shoreline washing and steaming.

Comment: One commenter disagreed

with the statement in the proposed

NRDAM/GLE technical document that

fish production is not negatively

affected by dredging.

Response: The Department

acknowledges, and the models

recognize, that dredging of a habitat

reduces egg and larval fish production

in the dredged habitat to zero initially,

and then production follows vegetative

and benthic recovery. The models

simply assume that adult fish

production is unaffected.

K. Assimilative Capacity Restoration

Comment: Several commenters argued

that assimilative capacity restoration

costs are not legally recoverable. A

number of commenters thought that

inclusion of damages for lost

assimilative capacity was overly

speculative. These commenters stated

that the presence of a spilled substance

only causes a meaningful reduction in

assimilative capacity if the resource will

be required to assimilate more of a

similar substance in the same area

before the spilled substance degrades.

The commenters argued that the type A

models merely assume that assimilative

capacity has been reduced. Some of

these commenters thought that the

assumption of an actual reduction in

assimilative capacity is particularly

troubling in the case of minor spills.

The commenters noted that if type B

procedures are used, trustees would be

required to demonstrate an actual

reduction in assimilative capacity. One

commenter noted that Ohio v. Interior

had stated that a procedure that

permitted unduly speculative

assessments would not constitute a best

available procedure under CERCLA. 889

F.2d at 462.

Response: The issue of whether lost

assimilative capacity is a legally

permissible category of damages was

decided and resolved by the Department

in 1986 and is beyond the scope of this

rulemaking. The only issues that the

Department is considering in this

rulemaking are: whether the type A

models adequately demonstrate a loss of

assimilative capacity; and, if so,

whether the models accurately compute

the costs for restoring that loss. The

Department believes that the

assimilative capacity restoration costs

computed by the final NRDAM/CME

and the NRDAM/GLE are based on

demonstrable, rather than speculative,

losses.

Assimilative capacity is an

ecosystem’s ability to repair itself by

digesting, degrading, transforming,

absorbing, or otherwise eliminating the

pollutants placed in it. The Department

recognizes that there are contrasting

views of the nature of assimilative

capacity. The purist position is that no

materials placed in aquatic

environments will ever simply

disappear. Some substances cannot be

broken down and will reenter and

recycle through the ecosystem even if

they have no detrimental effects. Other

substances may be completely digested

in the ecosystem and transformed into

harmless or naturally occurring

elements. This digestion, however, will

consume some of the ecosystem’s

resources (e.g., dissolved oxygen) at the

expense of natural processes and

components of the system. Thus,

following this purist approach, all

additions to a water body will change it

to a greater or lesser degree, and the

only way to ensure restoration of the

equilibrium in the ecosystem is to

eliminate or remove all introduced

material.

Recognizing, however, that absolute

removal of a discrete spilled substance

can be impractical, if not impossible,

some experts have adopted a more

pragmatic approach. Under this

approach, the assimilative capacity of a

water body is usually viewed in relation

to some water quality standard or level

of service. In other words, assimilative

capacity is the ability of a water body to

absorb a particular pollutant up to the

point where certain detrimental effects

are realized.

The Department carefully considered

both the purist and pragmatic

approaches to assimilative capacity.

Based on this consideration, the

Department included in the proposed

type A models a methodology for

computing assimilative capacity

restoration. After reviewing the public

comments, the Department has modified

that methodology to ensure that the

models more accurately quantify

assimilative capacity losses. The

Department believes that the modified

methodology is appropriate for

inclusion in the models.

The Department does not believe that

recovery of damages for lost assimilative

capacity using the type A models is

speculative. Trustees are authorized to

recover damages to restore injured

resources to their baseline conditions.

Baseline is measured in terms of the

services that the injured resources

would have provided in the absence of

the release. See 43 CFR 11.70(a). The

assimilation of pollutants is a real

service provided by natural resources

and is well-founded in scientific

literature. Assimilative capacity will be

reduced whenever a release occurs.

Releases use some of the assimilative

capacity of aquatic environments and so

long as the pollutants remain in the

environment, some portion of

assimilative capacity—a service

provided by the natural resource—is

lost. The Department does not agree that

reduction in assimilative capacity is

dependent on a subsequent release of

the exact same substance in the exact

same area. A release reduces

assimilative capacity regardless of

subsequent spill events.

Nevertheless, the Department

recognizes that there are practical

limitations on measuring and

addressing assimilative capacity loss,

particularly in the context of a

standardized procedure for minor

releases. The issue, then, is not whether

there is a reduction in assimilative

capacity but, rather, the extent of the

reduction and the type of actions that

are appropriate to restore the lost

assimilative capacity. As discussed

above, assimilative capacity can be seen

as the ability to absorb pollutants up to

a threshold where detrimental effects

occur. The type A models focus on

injury to biological resources. Therefore,

the threshold for meaningful loss of

assimilative capacity now built into the

models is mortality or loss of

production resulting in compensable

value. Releases that generate

compensable value related to mortality

or loss of production have, by

definition, exceeded the assimilative

capacity of the ecosystem. In the case of

such releases, the models estimate the

cost of restoring assimilative capacity.

The cost is based on the removal of a

mass equivalent in toxicity to the

amount of the spilled substance that

remains after concentrations have fallen

below acute toxicity thresholds and

after any habitat restoration actions are

completed. Such removal will return the

aquatic system to a state that is

functionally equivalent to its baseline

condition. When there has been no

acute mortality or loss of productivity,

the models do not calculate any

assimilative capacity restoration costs.

Comment: Some commenters asserted

that the models fail to take into account

how spatial, temporal, and chemical

factors affect the assimilative capacity

and function of a resource.

Response: The Department has

modified the models to account more

fully for the factors affecting
20600 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

assimilative capacity. The extent of

assimilative capacity reduction depends

on how long a substance remains in the

environment. The proposed versions of

the type A models did not consider

degradation rates when computing lost

assimilative capacity. The Department

has modified the models to correct for

the degradation rate of the released

substance relative to the degradation

rates of the contaminants found in the

sediment at the sites at which dredging

is presumed to occur. See Section 5.4.4,

Volume I of the NRDAM/CME and

NRDAM/GLE technical documents. The

Department believes that this

modification, along with the models’

methodology for ensuring that the

removed mass is equivalent in toxicity

to the released substance, adequately

account for the different factors affecting

assimilative capacity.

Comment: Several commenters

objected to basing assimilative capacity

restoration costs on the cost of dredging

projects outside the area affected by the

release. The commenters complained

that there was no relationship between

these dredging projects and the injured

resources. One commenter asserted that

inclusion of these damages was

motivated by a desire to circumvent the

normal appropriations process for

funding dredging projects unrelated to

the spill. Commenters, including one of

the independent technical reviewers,

observed that at dredging sites with

heavy contamination, less material

would have to be dredged than at sites

with lower levels of contamination.

These commenters noted that this

method generates dramatically different

figures for different geographic areas

and that such differences were unfair

because they were unrelated to the spill.

A few commenters stated that since the

Department seems to believe that

assimilative capacity is affected over

extremely large areas, the models

should base damages on the lowest

dredging cost for any of the provinces.

Some commenters, including one of

the independent technical reviewers,

also argued that it would be more costeffective to calculate damages based on

prevention of wastewater discharges

from point sources, such as publicly

owned treatment works (POTWs).

Another commenter suggested that the

rule allow PRPs the option of

determining and implementing more

cost-effective methods of restoring lost

assimilative capacity rather than paying

the damages calculated by the models.

Response: The Department agrees that

the method for restoring lost

assimilative capacity should be

reasonably related to the actual release

and cost-effective. The Department

believes that the methodology included

in the final type A models meets both

these standards. Biota are potentially

exposed to the released substance

throughout an entire biological

province; therefore, the Department

evaluated potential dredge sites on a

province-wide basis. Within each

province, the Department focused on

National Status and Trends (NST) sites

and International Joint Commission (IJC)

areas of concern because there are

considerable data available on the sites

and because they are heavily

contaminated. The higher the toxic mass

per volume at a site is, the cheaper is

the cost of dredging sediment equal in

toxicity to the remainder of the released

substance. Therefore, for each province,

the Department determined which NTS

site or IJC area of concern had the

highest toxic mass per volume and used

that site to develop assimilative capacity

restoration costs. See Section 13,

Volume I of the NRDAM/CME technical

document, and Section 9.4, Volume I of

the NRDAM/GLE technical document.

Had the Department restricted

dredging to areas closer to the site of the

release, the costs would likely have

increased significantly, because the

levels of contamination in those areas

would be lower than at NST sites and

IJC areas of concern. On the other hand,

had the Department considered NST

sites and IJC areas of concern well

beyond the boundaries of the province

in which the release occurred, the

dredging would be less clearly related to

the actual release.

The Department considered using the

cost of preventing discharges from point

sources, such as POTWs, as a possible

basis for assimilative capacity

restoration costs. However, the

Department was unable to locate

adequate data on point source

discharges for toxic chemicals.

Commenters presented no additional

information that would enable the

Department to develop assimilative

capacity restoration costs based on

reducing point source discharges.

With regard to allowing PRPs to

develop alternative methods of restoring

lost assimilative capacity, the objective

of the type A models is to provide a sum

certain on an inexpensive, expedited

basis. Allowing PRPs to develop

alternative restoration methods,

providing trustees with an appropriate

opportunity to evaluate the feasibility

and adequacy of the PRPs’ proposal, and

giving the public a chance to review the

proposal could undermine this

objective. Where the models predict

significant assimilative capacity

restoration costs, PRPs who believe that

they could restore lost assimilative

capacity in a more cost-effective manner

than that predicted by the type A

models would have the option of

funding type B procedures or pursuing

an appropriate settlement with the

trustees.

Comment: One commenter thought

that loss of assimilative capacity was a

legitimate basis for recovery but stated

that damages for the loss should be

characterized as compensable value

rather than restoration costs.

Response: The Department believes

that the damages for lost assimilative

capacity are correctly categorized as

restoration costs rather than

compensable value. Under the existing

regulations, compensable value is the

economic value that the public loses

until the injured resources recover. See

43 CFR 11.83(c)(1). The type A models

calculate damages for lost assimilative

capacity based not on economic value

lost to the public but rather the cost of

restoring baseline services.

Comment: One commenter noted that

the proposed NRDAM/CME in some

cases predicts that more of the

substance will remain in the

environment than was spilled in the

first place.

Response: This result was caused by

a coding error that the Department has

corrected in the final version of the

NRDAM/CME.

Comment: Commenters noted that,

contrary to assertions in the August 8,

1994, and the December 8, 1994, notices

of proposed rulemaking, the models do

compute habitat restoration costs and

assimilative capacity restoration costs

for the same release.

Response: The models compute

assimilative capacity restoration costs

for any toxic mass that remains in the

environment either because no habitat

restoration action is taken or because

habitat restoration does not fully remove

the toxic mass. The preamble and

technical documents have been

clarified. See Section 5.4.4, Volume I of

the NRDAM/CME and NRDAM/GLE

technical documents.

Comment: One commenter noted that

there are now 43, not 42, IJC areas of

concern in the Great Lakes.

Response: At the time that the

proposed NRDAM/GLE was being

developed, there were only 42 IJC areas

of concern. As more IJC areas of concern

and NST sites are identified, the

Department will consider updating the

models in future biennial reviews.

However, it was not feasible for the

Department to revise the NRDAM/GLE

to account for this one additional site

within the available time frame.

Comment: One commenter questioned

the use of standardized sediment LC50s
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20601

based solely on bulk sediment

concentrations.

Response: The LC50s used in the

models are for pore water

concentrations, not bulk sediment

concentrations.

Comment: One commenter stated that

the proposed NRDAM/GLE generated

inappropriately high assimilative

capacity restoration costs for releases of

metals. The commenter thought these

inappropriate costs resulted from

underestimating the rate at which

metals attenuate in the Niagara River

and Lake Ontario. The commenter

stated that metals fall to the bottom, are

buried, and pose no toxicity threat.

Response: As discussed in Section

VII.G of this preamble, the Department

has eliminated all pure metals from the

chemical database. For metal

compounds, the Department believes

that the NRDAM/GLE adequately

accounts for attenuation. The model

calculates the fate of the released

substance by partitioning the dissolved

fraction from the particulate fraction in

both the water and the sediments. The

LC50s used in the model for

assimilative capacity calculations are

limited to those for dissolved chemicals.

L. Restocking

Comment: Several commenters

questioned the reasonableness of the

methodology for invoking and

calculating restocking costs. A few

commenters thought that the proposed

NRDAM/CME should not include

restocking costs for species, such as

dolphins, polar bears, eagles, and

alligators, that have never been and are

unlikely to be restocked after a spill.

These commenters stated that including

restocking costs for such species was

particularly troubling in light of the

weakness of the model’s underlying

estimates of mortality for these species.

Further, the commenters thought the

Department’s restocking cost estimates

for captive breeding programs, in some

cases, came from unpublished sources

and lacked real-world precedent. The

commenters noted, for example, that

there was no reason to assume that

osprey and raptors cost the same to

restock as eagles. Finally, another

commenter considered the salmon

restocking costs included in the

proposed NRDAM/CME to be

unrealistically high.

Response: The Department agrees that

it is highly unlikely that trustees would

restock polar bears and, thus, has

deleted polar bear restocking costs from

the NRDAM/CME. The Department has

limited the rest of the restocking

component to those species that are

actually available from hatcheries or

commercial suppliers and used the

actual market prices of acquiring such

species. The Department believes that

this approach adequately ensures that

the restoration costs in the model are

realistic and reasonable. The

Department has added Table 12.7 to

Volume I of the NRDAM/CME technical

document to present the data obtained

from the International Animal

Exchange, Inc.

Bald eagles and other raptors have

been restored by hand-rearing

hatchlings in a number of States. The

models use the same costs for all raptors

because the activities and effort required

are similar for all species. The eagle

restocking cost may be considered a

general figure for all raptors.

The Department has revised the

calculations for fish restocking costs in

the NRDAM/CME. The proposed

NRDAM/CME used an average size for

all salmon species. The final model uses

species-specific parameters for salmon

in each of the three applicable

provinces. See Table 12.6, Volume I of

the NRDAM/CME technical document.

Comment: One commenter questioned

the assumed source of restocked

animals, noting that simply moving

animals from one location in the wild to

another would still leave the public

with a net loss.

Response: The Department believes

that translocation of animals in the wild

may, under some circumstances, be an

appropriate restoration action. However,

for purposes of the type A procedures,

the Department chose to consider only

restocking of captive-bred animals, the

cost of which is generally lower than the

cost of translocation in the wild. See

Table 12.7, Volume I of the NRDAM/

CME technical document.

Comment: One commenter thought

that it would be more appropriate to

consider predator control than

restocking for canvasback and redhead

ducks in the Great Lakes.

Response: After recovering damages

through the use of a type A procedure,

trustees may well decide that the

recoveries are better spent on predator

control rather than restocking. However,

the feasibility, effectiveness, and

methods of predator control are highly

site-specific. The Department does not

believe that adequate data are currently

available to include predator control

among the list of restoration actions

evaluated by the models.

Comment: One of the independent

technical reviewers thought the

restocking scenario described in the

proposed NRDAM/CME technical

document would result in a net loss of

fish and wildlife.

Response: The scenario does not

result in a net loss of fish and wildlife

because the model calculates a loss and

allows only one-to-one replacement,

with correction for restocking survival,

of missing individuals. The Department

has clarified the technical document.

See Section 5.4.3, Volume I of the

NRDAM/CME technical document.

Comment: One of the independent

technical reviewers noted that the

proposed NRDAM/CME technical

document stated that only fish that

would be caught are restocked in the

model. The technical reviewer thought

that all fish killed should be restocked,

not just those ultimately caught.

Response: The models assume that all

fish and shellfish killed are restocked, if

stocks are available. The technical

document has been clarified. See

Section 5.4.3, Volume I of the NRDAM/

CME technical document.

Comment: One of the independent

technical reviewers thought that the

models should grant habitat restoration

priority over restocking.

Response: The models decide whether

to invoke habitat restoration

independently from the decision

whether to restock. Therefore,

prioritization is not necessary.

M. Consideration of Costs and Benefits

of Active Restoration

Comment: Numerous commenters,

including some of the independent

technical reviewers, criticized the

models for failing to consider whether

the various active restoration

alternatives were warranted in light of

the relationship between the benefits of

those actions and the costs of the

alternatives. Some commenters offered

examples where the models computed

restoration costs that were millions of

dollars or hundreds of times greater

than estimated compensable values.

Many commenters thought that the

models should incorporate a decision

rule to screen out restoration actions

that would impose grossly

disproportionate costs.

Response: As it indicated in the

March 25, 1994, type B rulemaking, the

Department believes that the

relationship between costs and benefits

is an important factor in selecting an

appropriate restoration action. See 59

FR at 14271. The Department

acknowledges that the proposed rules

and models did not explicitly address

this factor. After careful consideration,

the Department has revised the models

to perform a cost-benefit analysis of

habitat restoration and restocking

actions.

If the relevant active habitat

restoration alternative would reduce
20602 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

compensable value or if restocking is

possible, then the submodel performs a

cost-benefit test of these forms of active

restoration. The submodel compares the

total costs of active habitat restoration

and restocking against the measured

benefits of such restoration (i.e.,

compensable value assuming natural

recovery minus compensable value

assuming active restoration). If the costs

exceed ten times the measured benefits,

then the submodel assumes, for

purposes of generating a damage figure,

that natural recovery, rather than active

restoration, will be used to reestablish

baseline conditions. If the costs do not

exceed the measured benefits by ten

times, then the submodel assumes, for

purposes of generating a damage figure,

that habitat restoration and restocking

will be implemented.

The Department determined in the

March 25, 1994, rulemaking that

although cost-benefit considerations are

an important factor in selecting an

appropriate restoration action when a

trustee uses type B procedures, the exact

determination of how to evaluate this

factor should be resolved on a case-bycase basis. Therefore, 43 CFR 11.82(d)

lists the relationship between costs and

benefits as one of several factors that

trustees must evaluate before selecting a

restoration action when using type B

procedures. The Department continues

to believe that this is the most

appropriate approach in the type B

context. However, in the type A context,

where a model, rather than the trustees,

determine the range and type of

restoration actions on which to base the

damage claim, and where the intent is

to minimize the level of analysis that

trustees must conduct, the Department

believes it is appropriate to impose a

bright-line standard.

The Department has concluded that

the evaluation of the costs and benefits

of active habitat restoration and

restocking versus natural recovery

should focus on incremental costs and

benefits. Therefore, the models compare

the total costs of active habitat

restoration and restocking against

compensable value assuming natural

recovery minus compensable value

assuming active restoration.

When determining what an

appropriate cost-benefit ratio would be

in the type A context, the Department

considered the dicta in Ohio v. Interior

suggesting three-to-one as a possible

ratio. See 880 F.2d at 443–44, n. 7.

However, the NRDAM/CME and

NRDAM/GLE quantify only a very

narrow range of compensable values.

Thus, the Department does not believe

that a three-to-one ratio is appropriate.

Therefore, the Department was left to

make this policy determination without

the benefit of clear empirical standards

or legal precedents. The Department has

selected a ratio of ten-to-one based on

its sense of fairness and reasonableness.

Although the models do impose a

uniform standard, the Department

continues to believe that a truly

‘‘correct’’ cost-benefit ratio depends on

site-specific factors. The standard

contained in today’s models is not

intended to suggest that a similar ratio

is appropriate in a type B context but

rather has been included in recognition

of the unique nature of the type A

procedures. Even when trustees use

type A procedures, if the ratio is

exceeded, they may nevertheless

conclude that compensable values

assuming natural recovery as

determined by the models will not

provide adequate funding for necessary

restoration actions. In such cases,

trustees are free to calculate damages

using type B procedures.

Finally, the Department has chosen

not to apply the cost-benefit test to

assimilative capacity restoration. The

Department believes that assimilative

capacity does have an economic value.

However, the Department is unaware of

any economic study that calculates the

consumer surplus or economic rent

associated with assimilative capacity.

Accordingly, the Department has not

included assimilative capacity in the

cost-benefit test since its inclusion does

not affect the calculation of

compensable values.

N. Damages for Fishing and Hunting

Losses

Comment: Some of the independent

technical reviewers noted that closures

to recreational fishing represent a

change in access rather than in catch

rate. These technical reviewers thought

that random utility models (RUMs)

should be used to value both the

changes in catch rates and in access,

noting that RUMs are designed to

capture substitution across sites.

Response: The Department

acknowledges that recently evolved

techniques for resource valuation could

potentially improve the calculation of

damages in the models. However,

inclusion of such techniques would

require considerable additional work,

including the development of a RUM

describing recreational choices across

the broad geographic regions covered by

the models and a database containing

the parameters required as inputs to the

RUM. The Department has concluded

that such additional work is not feasible

at this time. The Department may

reconsider this issue in future biennial

reviews of the models.

Comment: Commenters objected to

the calculation of damages for lost

recreational fishing on the grounds that

the Department had failed to link the

injury to a reduction in services by

using trip values rather than marginal

(per fish) values. Other commenters,

including some of the independent

technical reviewers, noted that all

species are assigned to a single mode of

recreational fishing. They stated that

data are available on percentage caught

by each mode, and recommended these

data be included in the models to

weight the recreational fishing values.

Response: Though not fully explained

in the proposed NRDAM/CME and

NRDAM/GLE technical documents, the

Department established the link

between the injury and a reduction in

services by calculating average trip

values (dollars of trip value per

kilogram of fish caught) and then

adjusting these values by applying ratios

of average trip values to marginal values

(additional trip value per fish caught)

that were obtained from studies that

have compared these values. The

Department has revised the technical

documents. See Section 9.3.4, Volume I

of the NRDAM/CME technical

document, and Section 6.3, Volume I of

the NRDAM/GLE technical document.

The Department acknowledges that

additional data on percentage of fish

caught by different modes of fishing are

becoming available. However, due to the

fact that the majority of species in a

particular area tend to be caught by a

dominant mode of fishing and that there

are not always major differences

between values in the various modes of

fishing, the Department does not believe

that weighting recreational fishing

values using data on percentages caught

by each fishing mode would

significantly improve the reliability of

the final damage figure. As additional

data become available, the Department

will reconsider this issue in future

biennial reviews.

Comment: One commenter noted that,

in an attempt to maximize total utility,

anglers tend to reduce the number of

fishing trips they take as the marginal

utility from fishing falls in response to

a reduction in the catch rate. This

commenter argued that the models

should, therefore, account for

reductions in participation in addition

to reductions in catch. The commenter

suggested that the models estimate

reductions in participation for spills

that exceed some given threshold

volume.

Response: The Department believes

that, while participation in fishing

activities may be affected by moderate

or large-scale spills, small spills are
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20603

likely to affect primarily the quality of

such activities. Specifically, the

Department believes that the principal

effect of small spills on recreational

anglers is a reduction in catch rather

than a reduction in fishing trips. The

commenter appears to agree with this

position by suggesting that the models

account for reductions in participation

for spills over a given threshold size.

However, where participation is

reduced, trustees may conduct

supplemental type B studies.

Comment: One commenter thought

that the models inappropriately

assumed that species that lacked catch

data had no recreational value.

Response: The Department recognizes

that there may be species for which

catch data are not available that

nevertheless have recreational value.

However, the only fish-related

compensable value that the models

compute is for lost harvests. Without

catch data, the models cannot determine

lost harvests and, thus, cannot compute

compensable value. If an injured fish

species has values unrelated to harvest,

then trustees may conduct supplemental

type B studies to capture those values.

Comment: A few commenters,

including some of the independent

technical reviewers, thought that the

lost recreational fishing and hunting

values used in the models were

outdated.

Response: The Department has not

updated the recreational fishing and

hunting values in the models. The

Department will revisit this issue during

the next biennial review.

Comment: One of the independent

technical reviewers questioned why the

hunting values included in the

proposed models did not account for the

effects of changes in effort.

Response: The Department is not

aware of any evidence that effort

changes in cases of minor spills.

Comment: Some of the independent

technical reviewers recommended that

the Department include habitat

equivalency analysis (HEA) in the

models.

Response: HEA is a method of

determining damages for interim losses

that does not require the explicit

calculation of the economic value lost

by the public. Instead, HEA bases

damages on the cost of obtaining or

creating additional acreage that would

provide the same habitat services as that

lost pending recovery of the injured

resources. While HEA has merit, the

Department has elected not to pursue its

inclusion in the type A models at this

time. The use of HEA to compute

compensation for interim losses is an

issue that extends beyond this

rulemaking. HEA is currently not listed

as one of the type B methodologies for

calculating compensable value,

although the regulations do allow use of

additional unlisted methodologies if

they meet certain criteria. The

Department is conducting a biennial

review of the type B methodologies and

will be examining the use of HEA in

that context. The Department believes

that inclusion of HEA in a type A

procedure should await the resolution

of the biennial review of the type B

procedures. Also, the availability and

cost of obtaining habitat equivalent to

that injured is highly site-specific. The

Department currently does not have

adequate data to incorporate HEA into

the models.

Comment: Commenters objected to

the method used to value lost

subsistence fishing. The commenters

stated that the proposed NRDAM/CME

does not clearly define subsistence

anglers and inappropriately assumes

that the full value of the subsistence

resource is lost without considering

substitutes. In addition, the commenters

argued that the proposed NRDAM/CME

measures subsistence loss by the gross

cost of an alternate food supply (rather

than considering net subsistence losses)

and adjusts the costs to account for

supposed differences in protein between

store-bought and wild-harvested fish

based on a study of birds, not fish.

Several commenters thought that

inclusion of damages for lost

subsistence fishing was legally

impermissible. On the other hand, one

of the independent technical reviewers

noted that subsistence hunting, not only

subsistence fishing, is significant in

Alaska and should be included in the

model.

Response: The Department

acknowledges that the proposed

NRDAM/CME failed to clearly define

subsistence anglers, failed to consider

substitutes, and inappropriately

measured subsistence loss as the gross

cost of an alternate food supply. All of

these shortcoming raise significant

questions about the reliability of the

model’s calculation of compensable

value for subsistence loss. Data are

unavailable at this time to correct these

problems. Therefore, the Department

has decided to delete subsistence losses

from the NRDAM/CME. Because the

Department has decided to delete

subsistence losses for technical reasons,

it is not necessary for the Department to

address the legal permissibility of

trustees recovering natural resource

damages for subsistence losses.

Comment: Some commenters,

including some of the independent

technical reviewers, objected to the

inclusion in the models of damages for

loss of commercially harvested fish and

furbearers. These commenters rejected

the explanation that inclusion of

damages for such losses was designed to

compensate the public for lost economic

rent. The commenters noted that the

government does not in fact charge rent

for commercial harvests and concluded

that the public, therefore, does not incur

any loss of economic rent. Commenters

argued that the models were not

capturing the public’s lost economic

rent but rather were inappropriately

calculating the commercial users’

private losses, which are not recoverable

as natural resource damages under

CERCLA. The commenters cited Satsky

v. Paramount Communications, Inc. for

the proposition that trustees may only

bring claims ‘‘for injuries to interests

which all citizens hold in common.’’ 7

F.3d 1464, 1470 (10th Cir. 1993). The

commenters argued that private

economic interests, such as commercial

losses, are not interests that all citizens

hold in common. Citing various floor

debates on the Superfund Amendments

and Reauthorization Act, the

commenters argued that Congress

intended the double recovery

prohibition to bar natural resource

damage claims for losses that are subject

to private recovery. Commenters also

noted that if damages for such losses are

retained in the models, then serious

double recovery problems arise because

commercial users will assert

overlapping claims.

Response: The type A models include

damages for lost commercial harvests in

order to capture lost economic rent. The

issue of whether lost economic rent is

a legally permissible category of

damages was decided and resolved by

the Department in 1986 and is beyond

the scope of this rulemaking. The only

issues that the Department is

considering in this rulemaking are:

whether economic rent is, in fact,

generated by commercially harvested

species; if so, whether the type A

models correctly calculate any loss of

that economic rent resulting from

releases covered by the models; and

whether the rule adequately protects

against double recovery.

In the preamble to the original type B

rule, economic rent is defined as ‘‘the

excess of total earnings of a producer of

a good or service over the payment

required to induce that producer to

supply the same quantity currently

being supplied.’’ 51 FR at 27691. In

other words, economic rent for

commercially harvested resources is the

fee that commercial harvesters could

pay to the government and still find

harvesting economically feasible.
20604 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

Commercial harvesters invest capital

in equipment (e.g., gear, traps, and

boats). This capital could have been

liquidated and put to another use, such

as investment in a bank. Therefore,

commercial harvesting is worthwhile

only if the harvester receives a price for

the harvest that both covers labor and

fuel costs as well as provides a

reasonable return on capital. To the

extent that the harvester receives a price

that exceeds costs plus a reasonable

return on capital, the government could

charge a fee and the harvester would

continue to engage in harvesting. Thus

economic rent is generated.

The Department believes that

economic rent is being generated by

commercially harvested fish and

wildlife. The one situation in which

economic rent is clearly eliminated is

when natural resources are exploited to

the point that all profits, including

economic rent, have been competed

away. This situation arises when

commercial harvests are not regulated

and, thus, harvesters have free and

unlimited access. Economic theory

predicts that in such cases harvesters

will ignore both the value of the

resources for future use as well as the

costs of crowding. Fisher, A.C.,

Resource and Environmental

Economics, New York: Cambridge Univ.

Press, 1981.

One way of preventing this situation

and generating economic rent, is to

charge fees. Currently, resource

managers do not generally charge fees

except to cover administrative costs of

processing permits. See, e.g., Magnuson

Act, 16 U.S.C. 1854(d). However,

resource managers do regulate

commercial harvesting through limits

on the gear that may be used, limits on

the length of the harvest season, catch

restrictions, tradeable permits for

limited entry or individual catch quotas,

and other programs. For example,

NMFS has recently established a pilot

program to buy back fishing permits to

restore stocks of cod, haddock, and

flounder in the Atlantic Ocean. These

programs are designed to protect the

resources for future use. The

Department believes that these programs

do in fact curb overexploitation of

stocks and thus prevent profits

(including economic rent) from being

driven down to zero. For example,

Alaska salmon and herring fisheries are

regulated with tradeable entry permits.

The aggregate value in 1988 of all

permits in the salmon, herring, and

herring roe fisheries was $925 million.

Market prices are largely set on a

national or international basis.

Therefore, in the case of minor spills, it

is unlikely that market prices will

change. Also, total biomass effects

should be limited for minor spills, thus

it is unlikely that there will be long-term

effects on the catchability of resources.

Finally, the Department believes it is

reasonable to assume for minor spills

that the same number of commercial

harvesters will continue to expend the

same amount of economic resources to

conduct harvests and that the markets

for the necessary labor and capital

inputs to commercial fishing are

competitive. Therefore, the type A

models compute damages based on the

harvesters’ forgone revenue, which is

the market price the harvesters could

have received at the time the resources

would have been harvested. The

Department believes that this figure will

capture lost economic rent.

With regard to potential double

recovery, the Department acknowledges

that in some cases commercial

harvesters may bring private causes of

action that include economic rent. As

noted above, resource managers

generally do not charge fees to capture

economic rent; therefore, when

commercial harvesters sell their

harvests they obtain a profit that

includes economic rent. Under OPA,

commercial harvesters have a specific

private cause of action. CERCLA does

not grant commercial harvesters a

private cause of action. However, some

commercial harvesters, such as

commercial fishermen in coastal waters,

probably do have private causes of

action for hazardous substance-related

injuries under State law or common

law. When commercial harvesters bring

a claim for lost profit it will most likely

include economic rent. Therefore, if

trustees also bring a claim for lost

economic rent there will be a potential

double recovery problem.

The governmental regulation of

commercial fish and wildlife harvest

implies a public concern that these

resources be managed in order to

sustain their contribution to economic

productivity. The public’s value for

commercial harvesting is further

reflected in express policy statements

that the government is committed to

promoting resources’ contribution to

economic productivity. See, e.g., Fish

and Wildlife Act of 1956, 16 U.S.C.

742a. Therefore, when there are

reductions of commercial harvests, the

public suffers a loss.

If commercial harvesters can and do

bring a private cause of action, then the

harvesters may be fully compensated

and the public’s interest in promoting

commercial harvests may be satisfied. If

harvesters are compensated for full

social losses, then trustees should not

recover separate damages for lost

economic rent. However, in some cases

commercial harvesters may not have a

private cause of action or their

recoveries may be subject to geographic

or temporal limitations. For example,

commercial harvesters may be limited to

recovering damages incurred during the

period of formal closure, or incurred in

the area closed or in the area in which

fish were directly exposed to the

released substance. See, e.g., Golnoy

Barge Co. v. M/T Shinoussa, Civ. No. H–

90–2414, 1993 WL 735038 (S.D. Tex.

Aug. 17, 1993). In other cases,

commercial harvesters may choose not

to bring private causes of action. If

commercial harvesters do not obtain

direct full compensation, then the

public’s interest is not satisfied and the

trustees may bring a claim for lost

economic rent.

For minor releases where damages

may be relatively low and data

establishing injury and causation may

be difficult to obtain, the Department

believes that it is unlikely that

commercial harvesters will go to the

expense and trouble to pursue a legal

claim. Therefore, the Department has

retained the calculation of lost

economic rent in the models. However,

to prevent double recovery, § 11.44(d)

provides that if the trustee is aware of

reliable evidence that a private party has

recovered damages for commercial

harvests lost as a result of the release,

the trustee must eliminate from his or

her claim any damages for such lost

harvest that are included in the lost

economic rent calculated by the model.

When the Assessment Plan is made

available for public review and

comment, PRPs and commercial

harvesters will have an opportunity to

alert trustees to any private actions for

lost commercial harvests.

Comment: A few commenters,

including some of the independent

technical reviewers, thought that the

prices used to calculate damages for lost

commercial harvests were invalid

because they did not account for

seasonal and regional variations.

Commenters also stated that the data

used were from 1984 through 1988 and

should be updated.

Response: The models account for

seasonal and regional differences in

commercial prices to the extent possible

given available data. In the Great Lakes,

pelt prices were available on a State-byState basis. The Department used these

prices to develop average prices for each

of the Great Lakes. In the coastal areas,

pelt prices were available only on a

regional basis.

At the time the Department performed

the bulk of the work on the commercial

fisheries component, 1984 through 1988
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20605

was the most recent 5-year period for

which final statistics were available for

the offshore zone in which the catch

occurred (rather than ports where

harvest was taken). The Department

decided to average the figures over a

five-year period to eliminate short-term

variability. The Department believes

that the commercial fishing statistics

currently incorporated in the models are

reliable. However, as additional data

become available, the Department will

consider updating the models during

future biennial reviews.

O. Damages for Lost Wildlife Viewing

Comment: One commenter supported

the proposed approach for calculating

damages for lost wildlife viewing as

reliable and reasonable. However, most

commenters criticized the approach.

Commenters noted that the Department

itself appeared to have serious

reservations about the approach. A

number of commenters thought that the

approach would consistently

underestimate damages; others thought

that damages would be overestimated.

Some commenters stated that the

Department’s methodology for

calculating wildlife viewing losses was

so unreliable that such losses should be

deleted from the models.

Several commenters thought it was

incorrect to assume that a given

reduction in wildlife population would

produce a comparable reduction in the

wildlife seen. Thus, the commenters

concluded that the Department was

unable to link the injury to a reduction

in services. The commenters further

stated that the calculation used

inappropriate assumptions and studies

to calculate the value of a wildlife

viewing trip on a per-animal basis.

A few commenters thought the values

appear arbitrary since they vary so

widely by province. One commenter

suggested that the wide variations in

province values be eliminated either

through the use of uniform average

values or through the deletion of

extreme values. On the other hand,

some commenters thought the models

did not adequately account for the

variable characteristics of affected sites.

Response: In the notices of proposed

rulemaking, the Department solicited

comment on a number of aspects of the

proposed methodology for determining

damages for lost wildlife viewing. 59 FR

at 40328–29 and 63311–12. Based on its

careful consideration of the comments it

received, as well as its own

reexamination of the models, the

Department has modified the

methodology and believes that it is

sound.

Wildlife viewing is one of the most

significant direct use services that

wildlife provide to humans. Inclusion of

lost wildlife viewing damages in the

type A models necessitated that the

Department draw conclusions about the

relationship between changes in

wildlife populations and changes in the

perceptions of wildlife by viewing

participants. There is no known

empirical research that indicates how

participants perceive changes in

wildlife populations. The proposed

models assumed that a given percentage

reduction in wildlife populations results

in the same percentage reduction in the

wildlife seen by participants.

The Department has determined that

percentage reductions in wildlife

viewing perception could be lower or

higher than the percentage reduction in

wildlife populations. For example, a

wildlife population may consist of 100

animals yet the public may only

perceive, on average, 50 of those

animals. If a spill were to kill 50 percent

of the population, then the public’s

perception of the population would be

reduced by 20 percent if the 50 killed

animals included only 10 of the animals

the public normally sees. However, if

the 50 killed individuals included 30 of

the animals the public normally sees,

then the change in perception would be

60 percent. Therefore, in the absence of

empirical evidence on the subject, the

Department has decided to assume that

percentage reductions in wildlife

viewing perception are equal to

percentage reductions in wildlife

populations.

When determining how a given

reduction in the number of animals

viewed affects the value the public

derives from viewing, the Department

relied on the only available studies that

identified a marginal value for wildlife

viewing (Loomis et al. (1989) and

Cooper and Loomis (1991)). The

Department believes that these studies

are reliable. The Department

acknowledges that one of the studies

dealt with trips that were not taken

primarily for the purpose of wildlife

viewing. However, contrary to the

assertions of some commenters, the

studies specifically examined how

changes in the number of animals seen

affected the value of the trips. Therefore,

the wildlife viewing values used in the

type A models do not reflect any other

non-viewing aspects of recreational

trips.

The biological effects submodel

quantifies wildlife mortality in terms of

the number of animals killed. Therefore,

the Department needed to develop peranimal viewing values. The Department

developed such per-animal values by

using Loomis et al. (1989) and Cooper

and Loomis (1991) to establish the

relationship between changes in

wildlife seen and changes in value and

by using FWS’ National Survey of

Fishing, Hunting, and WildlifeAssociated Recreation to establish total

viewing values for particular species.

The Department first estimated the total

value of wildlife viewing at ocean- or

lake-side for an entire State. Then the

Department allocated this total value

among species and wildlife individuals

within species that reside along the

State’s ocean- or lake-side. For further

discussion of this methodology, see

Section 8.4, Volume I of the NRDAM/

CME technical document, and Section

6.4.1, Volume I of the NRDAM/GLE

technical document.

The Department recognizes that the

per-animal viewing values assigned by

the models for some species vary widely

by province. However, the Department

has concluded that these variances are

not errors that need to be corrected but,

rather, reflect actual and relevant

regional differences. The value that the

public derives from viewing a particular

animal in a particular area depends on

how many people engage in wildlife

viewing in that area and how many

animals of that type there are to view in

that area. Therefore, the models

appropriately contain relatively low peranimal values for species that are

abundant and for areas with low

participation in wildlife viewing.

Conversely, the models contain higher

per-animal values for less abundant

species and for areas with higher

wildlife viewing participation.

Not only are the regional variances in

per-animal values appropriate, but also,

such variances do not lead to unrealistic

differences in the damage figures

calculated by the models for particular

releases. When determining damages for

a particular release, the models

calculate damages for lost wildlife

viewing based on the probability that

the release will kill wildlife. The

probability that an animal will come

into contact with, and be killed by, a

release is directly related to the wildlife

abundance in the area affected by the

release. In areas with low wildlife

abundance, minor releases would have

a low probability of killing wildlife.

Therefore, although the per-animal

values in these areas may be

significantly higher than in areas of high

abundance, the actual damage figure

may not be.

Comment: Some commenters

contended that the methodology for

calculating viewing damages relies on

assumptions that overstate the number

of wildlife viewing trips to affected
20606 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

areas. Some commenters also claimed

that the Department had used unreliable

survey data to derive per-animal

viewing values. Several commenters

thought the models used outdated data.

Response: The Department has

revised the wildlife viewing damage

component of the models to reflect more

recent data. When developing the

proposed models, the Department used

FWS’ 1985 National Survey of Fishing,

Hunting, and Wildlife-Associated

Recreation. This survey was updated in

1991. The Department has revised the

final models to reflect this update. FWS

has conducted wildlife-related

recreation surveys roughly every 5 years

since 1955. The results of these surveys

are widely disseminated and are relied

upon both by governments and by

private individuals for a range of

purposes. The Department believes it is

appropriate to use these surveys to

determine participation rates for

wildlife viewing as well as the value of

wildlife viewing trips.

Comment: A few commenters,

including some of the independent

technical reviewers, suggested that the

proposed models be expanded to

account for viewing losses incurred by

individuals other than residents of

coastal counties. One commenter stated

that in Michigan, regional populations

are not concentrated either in lake shore

counties or at substantial distances

inland and suggested that the NRDAM/

GLE incorporate lost wildlife viewing

on a two-county deep basis. One of the

independent technical reviewers noted

that the absence of damages for lost

viewing by out-of-State tourists was a

significant problem in Alaska.

Response: The Department has

revised the NRDAM/CME to account for

impacts on the populations of coastal

States rather than just coastal counties.

See Section 8.4, Volume I of the

NRDAM/CME technical document.

Wildlife viewing damage calculations in

the NRDAM/CME rely on State-level

estimates of participation rates for

wildlife viewing at the ocean. The

Department believes that it is more

appropriate to apply these State-level

participation rates to State populations

than to county populations in the

NRDAM/CME.

The Department has not applied the

participation rates in the final NRDAM/

GLE to the entire State population due

to the existence of alternative recreation

sites in other parts of the Great Lakes

States. Instead, the Department has

generally limited the participation rate

to the populations of lake-side counties

in the NRDAM/GLE. In a few instances

involving very narrow counties, the

Department has gone beyond the lakeside county to include residents of areas

within an average one-way trip distance

from the provinces where injury

occurred. Statewide average

participation rates were used in the

NRDAM/GLE due to a lack of reliable

data at the county level.

The Department recognizes that out-of

State visitors may experience viewing

losses; however, adequate data are not

currently available to incorporate such

losses into models. As more data

become available, the Department may

reconsider this issue in future biennial

reviews. Meanwhile, the rule allows

trustees to conduct supplemental type B

studies to assess damages for such

losses.

Comment: Some commenters,

including a few of the independent

technical reviewers, suggested including

viewing losses incurred by individuals

under the age of 18. One commenter

noted that the Department had relied on

wildlife participation survey data

supplied by individuals 16 years or

older but used population data that only

included individuals 18 years or older.

Response: The Department has

revised the models to include viewing

losses experienced by individuals 16

years of age and older.

Comment: Some commenters,

including a few of the independent

technical reviewers, thought that spills

could affect not only the quality of the

wildlife viewing trips but also the

number of trips taken. These

commenters thought the models should

account for this effect.

Response: Adequate data are not

currently available to incorporate

damages for lost participation in

wildlife viewing. Further, while

participation in wildlife viewing may be

affected by moderate or large-scale

releases, minor releases, for which the

type A models are designed, are likely

to affect primarily the quality of such

activity. As more data become available,

the Department may reconsider this

issue in future biennial reviews.

Comment: A few commenters thought

the models did not account for all

species that had viewing value.

Response: The Department believes

that the species addressed by the

models account for the vast majority of

viewing values.

Comment: One commenter noted that

the deaths of migratory species could

result in viewing losses in locations

beyond the spill site and thought that

the models should account for such

losses.

Response: The Department

acknowledges that releases can result in

off-site viewing losses; however,

adequate data are not currently available

to incorporate such losses into models.

As more data become available, the

Department may reconsider this issue in

future biennial reviews. Meanwhile, the

rule allows trustees to conduct

supplemental type B studies to assess

damages for such losses.

Comment: Some commenters asked

whether the models considered the

effect of closures on wildlife viewing

losses.

Response: The models do not address

the effect of closures on wildlife

viewing. The models only compute

mortality-related wildlife viewing

losses.

P. Damages for Beach and Boating

Closures

Comment: The Department received

several comments on the proposed

NRDAM/CME’s methodology for

calculating damages for beach closures.

A few commenters thought that the

Department had made unsubstantiated

and questionable assumptions in

estimating beach visitation. Some

commenters, including one of the

independent technical reviewers,

claimed that the Department had failed

to account adequately for differences in

visitations and values associated with

different beach types and different

seasons. One independent technical

reviewer stated that beach visitation is

highly variable within provinces, and

that more localized visitation data could

be mapped in a GIS from survey data.

Response: The Department could not

locate adequate data to develop separate

per-person values for visiting Federal

beaches versus non-Federal beaches.

However, the Department believes the

NRDAM/CME adequately accounts for

differences between the two types of

beaches through the use of different

visitation figures. A sample of monthly

visitation data was taken from

representative beaches in each

economic province. This sampling was

designed to account for differences in

visitation that exist between economic

provinces. The Department also

collected separate visitation data for

National Seashores and other public

beaches. The user is required to enter

the type of beach affected (National

Seashore or other public beach) as an

input to the NRDAM/CME. Further,

before the compensable value submodel

applies an average beach use value to

the estimated loss in beach use, the

submodel adjusts the value to account

for seasonal variations. The NRDAM/

CME uses seasonal variations in the

duration of beach visits as a reasonable

approximation of the seasonal variations

in beach use values. Data on the

duration of beach visits were available
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20607

for National Seashores, but not for other

public beaches. Therefore, the

Department applied the National

Seashore duration data to other public

beaches. For further discussion, see

Section 10, Volume I of the NRDAM/

CME technical document.

Comment: Several commenters raised

concerns about valuation of beach

closures in the proposed NRDAM/GLE.

Some commenters criticized the use of

studies of saltwater beaches to value

Great Lakes beach use. A few

commenters stated that the studies the

Department used to value Great Lakes

beach use were outdated. Other

commenters complained that the

NRDAM/GLE used the same values for

Federal and non-Federal beaches.

Response: In the NRDAM/GLE, the

per-day value of beach recreation is

based on the average of several values

reported for general beach recreation.

The Department acknowledges that

basing beach-related recreation values

on studies carried out exclusively at

Great Lakes locations would have been

ideal. However, no such studies were

available. Intuitively, beach recreation

on the Great Lakes combines some

aspects of seashore beach recreation

with some aspects of freshwater beach

recreation. Therefore, the Department

used a range of studies, including both

studies of saltwater beach recreation as

well as studies of freshwater beach

recreation.

The Department believes that the data

used are still the best available. If

additional data on the value of beachrelated recreation in the Great Lakes

become available, the Department will

consider incorporating such data in the

NRDAM/GLE during future biennial

reviews.

Data limitations required that the

Department make assumptions

concerning the distribution of monthly

trips to non-Federal lake shores. The

NRDAM/GLE assumes that the

distribution is identical to the

distribution of monthly trips to National

Lake shores. See Section 6.4.2, Volume

I of the NRDAM/GLE technical

document.

The Department could not locate

adequate data to develop separate perperson values for visiting Federal

beaches versus non-Federal beaches.

However, the Department believes the

NRDAM/GLE adequately accounts for

differences between the two types of

beaches because the per-person values

translate into different per-meter values

for Federal and non-Federal beaches.

Comment: Some of the independent

technical reviewers were confused by

the discussion in the proposed technical

documents on consideration of

substitutes when valuing beaches. They

recommended that values from

appropriate studies be selected based on

an understanding of the welfare

economics of substitutes. Specifically,

they expressed concern over the

Department’s use of studies of loss of

beach use over large regions. The

technical reviewers thought that such

studies would not account for

individuals’ ability to substitute one

beach for another within a given region

and, thus, would not correctly capture

the value of particular beaches.

Response: The Department did use

studies that account for the effect of

substitution. See Section 10.3.2, Volume

I of the NRDAM/CME technical

document.

Comment: One of the independent

technical reviewers suggested that

losses on private beaches should be

included.

Response: CERCLA authorizes

trustees to pursue claims only for

injuries to public resources, namely

those resources ‘‘belonging to, managed

by, held in trust by, appertaining to or

otherwise controlled by’’ the United

States, a State, or an Indian tribe.

CERCLA sec. 101(16). Private beaches

will generally not constitute public

resources. Therefore, the rule only

allows trustees to use the type A models

for public beaches.

Comment: One of the independent

technical reviewers stated that the

NRDAM/CME should be modified to

allow for the recovery of damages for

lost use of rocky shoreline.

Response: The Department was

unable to identify sufficient data on the

relative value of recreation on different

shoreline types in coastal and marine

environments to permit distinctions

between rocky and sandy shorelines.

Therefore, the models compute damages

for lost use of all types of closed Federal

or State beaches; however, the models

assign the same values regardless of

habitat type. The Department believes

that this approach is reasonable in light

of the geographic breadth of the studies

used to develop the beach values in the

models. Further, although the August

1994 proposed rule required trustees

who used the NRDAM/GLE to specify

whether a closed beach was rocky or

sandy, the model itself did not assign

different values based on that

designation. Therefore, the Department

has revised the final rule to remove the

requirement.

Comment: Several commenters

thought the models used unreliable

boating area coefficients that were likely

biased upward. The commenters

complained about the use of freshwater

boating studies to determine a boating

value for coastal and marine waters in

the proposed NRDAM/CME. The

commenters stated that marine boating

is different from freshwater boating.

Some commenters, including some of

the independent technical reviewers,

thought that the coastal regions of the

United States were so heterogenous that

applying one boating value to the entire

coastline of the United States was not

appropriate.

Further, the commenters stated that

the proposed NRDAM/GLE

inappropriately assumed that all boat

trips were evenly distributed along the

Great Lakes shoreline, which would

result in an overestimate of damages.

These commenters also thought the

studies used to derive boating value in

the NRDAM/GLE were unpublished and

outdated, and inappropriate for the

transfer of values.

Response: The Department was

unable to establish the similarity of

marine boating to freshwater boating for

the NRDAM/CME. Therefore, the

Department has eliminated the

calculation of lost boating values from

the NRDAM/CME.

As to the NRDAM/GLE, the density of

recreational boating is higher near ports.

Thus, due to the greater likelihood of

spills occurring near port facilities, the

Department believes the even allocation

of boating trips used in the model could

tend to underestimate the number of

boating trips that would be affected by

a small spill rather than overestimate

the value.

The Department does not agree that

the models calculate only upwardly

biased boating damages. In the NRDAM/

GLE, lost trips are estimated using a

formula that distributes the estimated

number of trips across the total area of

water covered by the near shore

forecast. In some areas this may result

in underestimates of the number of

affected boating trips. For example,

areas near major ports or marina

facilities are likely to have a higher

density of boating trips than is assumed

in the NRDAM/GLE. Nevertheless, the

Department believes that in those areas

when type B procedures cannot be

performed at a reasonable cost, trustees

should have the option of using the

NRDAM/GLE.

Q. Judicial Review and the Rebuttable

Presumption

Comment: Some commenters

supported proposed § 11.91(c)(2), and

the Department’s related statements

regarding which elements of a type A

damage assessment can be challenged

following application of the NRDAM/

CME or NRDAM/GLE in a specific case,

and which aspects of the rule (which
20608 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

incorporates the models) must be

challenged within 90 days of

promulgation, as provided by section

113(a) of CERCLA. Proposed

§ 11.91(c)(2) states that judicial review

of a type A damage assessment shall be

limited to the trustee’s decision to use

the type A procedure and the incidentspecific data supplied by the trustee. It

further states that the decision to use the

type A procedure and the incidentspecific data collected by the trustee

receive CERCLA’s rebuttable

presumption. The commenters

supporting this proposed provision

suggested that it would reduce the

potential for litigation and attendant

delays to restoration, although they

conditioned their support on how the

Department responded to their other

comments.

Numerous other commenters strongly

objected to proposed § 11.91(c)(2), as

beyond the Department’s authority and

as contrary to the two provisions in

CERCLA interpreted and applied in

proposed § 11.91(c)(2). These

commenters asserted that proposed

§ 11.91(c)(2) is outside of the

rulemaking authority provided by

section 301(c)(1) of CERCLA, and

therefore beyond the Department’s legal

authority. These commenters stated that

while the Department has authority to

promulgate regulations for assessments,

it does not have authority to prescribe

what effect those assessments will have

in future judicial proceedings.

These commenters also asserted that

the Department’s proposed rule

language that judicial review of a type

A assessment in a specific case would

be limited to the trustee’s decision to

use the type A procedure and the

incident-specific data supplied by the

trustee is contrary to sections 113 and

107(f)(2)(C) of CERCLA and the

Administrative Procedure Act (5 U.S.C.

551 et seq.). These commenters stated

that because CERCLA provides a

rebuttable presumption to assessments

performed in accordance with the

regulations, CERCLA allows a PRP to

introduce any relevant evidence that

may rebut the presumption. In the view

of these commenters, proposed

§ 11.91(c)(2) would deny PRPs any

meaningful opportunity to rebut the

rebuttable presumption, effectively

rendering the presumption irrebuttable.

These commenters interpreted section

113(a) of CERCLA as only barring future

judicial review of whether the

regulations are valid and meet statutory

requirements. Section 113(a) does not,

according to these commenters,

preclude judicial consideration of all

relevant evidence in an assessment not

performed at the time the regulations

are reviewed—e.g., evidence in a

particular case that the computer model

grossly overstates the number of affected

fish and wildlife. Some commenters

suggested that application of proposed

§ 11.91(c)(2) would raise constitutional

due process questions.

Finally, some of these commenters

objected to the provisions in proposed

§ 11.91(c)(2) that the rebuttable

presumption applies to the trustee’s

decision to use the type A procedure

and the data inputs. These commenters

stated that CERCLA’s rebuttable

presumption is granted only to the final

results of an assessment, not to

intermediate steps such as the decision

to use the type A procedures and the

data input selections. These

commenters also asserted that the

Department had provided no criteria for

ensuring the accuracy and reliability of

site-specific data inputs, and that absent

such regulatory criteria, the inputs

would not be entitled to the rebuttable

presumption. The commenters cited the

absence of a rebuttable presumption for

the statement of trusteeship as an

example where the Department

concluded that the absence of guidance

resulted in the absence of a rebuttable

presumption.

Response: The Department has given

this issue careful consideration, and

decided not to include proposed

§ 11.91(c)(2) in today’s final rule.

Whether or not a court ultimately would

uphold the authority of the Department

to promulgate proposed § 11.91(c)(2),

and the interpretation of CERCLA

reflected in it, the Department has

concluded that there is sufficient

uncertainty about the precise effect of

sections 107(f)(2)(C) and 113(a) of

CERCLA, as applied in a specific case,

to warrant leaving proposed

§ 11.91(c)(2) out of the rule at this time.

The Department recognizes that there

are numerous scenarios giving rise to

natural resource damage claims.

Whether or not proposed § 11.91(c)(2) as

applied would be overly broad could

depend on the specific circumstances of

a given case. Aside from whether the

commenters objecting to this provision

are legally correct, the questions raised

have convinced the Department that this

issue is best addressed outside the

rulemaking context, at least until

additional experience has been gained

through case-specific application of

these simplified procedures. Therefore,

the Department has concluded for now

that the precise delineation of

CERCLA’s preclusive review and

rebuttable presumption provisions to

type A damage assessments is best left

to specific cases. As a result, the

Department need not address whether it

has the legal authority under section

301(c)(2) to promulgate proposed

§ 11.91(c)(2), nor whether that section

accurately interprets CERCLA.

The Department does note that some

of the comments interpreting CERCLA’s

rebuttable presumption provision

appear largely to read CERCLA’s

preclusive review provision out of the

statute. Undoubtedly, Congress

intended that PRPs have a meaningful

opportunity to rebut specific aspects of

a trustee’s case, but not if it is a ‘‘matter

with respect to which review could

have been obtained’’ in a challenge to

the regulations. CERCLA sec. 113(a). In

the case of the type A rules, the validity

of the regulations themselves is closely

related to the content and workings of

the incorporated computer models. The

Department believes that section 113(a)

of CERCLA requires that challenges to

aspects of the rule that are clearly

discernible from the rule language, the

models, the incorporated technical

documentation, and this Federal

Register notice be brought within 90

days after promulgation. Sections

107(f)(2)(A) and 113(a) of CERCLA

should be read in harmony with one

another.

Also, contrary to the view of some

commenters, the statutory language of

CERCLA does not limit the effect of the

rebuttable presumption to the ‘‘final

results’’ of an assessment. Rather,

section 107(f)(2)(C) of CERCLA provides

that ‘‘[a]ny determination or assessment

of damages * * * made * * * in

accordance with the regulations * * *

shall have the force and effect of a

rebuttable presumption.’’ Although the

Department has decided not to

promulgate regulatory language

delineating the scope of the rebuttable

presumption, the statute appears to be

worded more broadly than was

recognized by these commenters.

Furthermore, the rule does provide

procedures requiring trustees to include

data inputs in the Assessment Plan,

which is subject to public review and

comment. As such, the rule does

contain procedural criteria to ensure the

accuracy and reliability of data inputs

through a public review and comment

process. The commenters also failed to

recognize a primary reason for the

Department declining to afford the

rebuttable presumption to the statement

of trusteeship. Unlike a statement of

trusteeship, which is in essence a

legally-founded assertion, data inputs

are factual in nature and can be

checked, reviewed, and verified through

the public comment process.
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20609

National Environmental Policy Act,

Regulatory Flexibility Act, Paperwork

Reduction Act, and Executive Orders

12866, 12630, 12778, and 12612

The Department has determined that

this rule does not constitute a major

Federal action significantly affecting the

quality of the human environment.

Therefore, the Department has not

prepared any further analysis pursuant

to section 102(2)(C) of the National

Environmental Policy Act (43 U.S.C.

4332(2)(C)).

The Department certifies that this rule

will not have a significant economic

effect on a substantial number of small

entities under the Regulatory Flexibility

Act (5 U.S.C. 601 et seq.). The rule

provides technical procedural guidance

for the assessment of damages to natural

resources. It does not directly impose

any additional cost. As the rule applies

to natural resource trustees, it is not

expected to have an effect on a

substantial number of small entities.

This rule does not contain

information collection requirements that

require approval by the Office of

Management and Budget (OMB) under

the Paperwork Reduction Act (44 U.S.C.

3501 et seq.).

OMB has reviewed this rule under

Executive Order 12866. This rule does

not have takings implications under

Executive Order 12630. The Department

has certified to OMB that this rule meets

the applicable standards provided in

Sections 2(a) and 2(b)(2) of Executive

Order 12778. This rule does not have

federalism implications under Executive

Order 12612.

List of Subjects in 43 CFR Part 11

Coastal zone, Environmental

protection, Fish, Hazardous substances,

Incorporation by reference, Indian

lands, Marine resources, National

forests, National parks, Natural

resources, Public lands, Recreation

areas, Sea shores, Wildlife, Wildlife

refuges.

For the reasons set out in the

preamble, Title 43, Subtitle A of the

Code of Federal Regulations is amended

as follows:

PART 11—NATURAL RESOURCE

DAMAGE ASSESSMENTS

1. The authority citation for Part 11

continues to read as follows:

Authority: 42 U.S.C. 9651(c), as amended.

Subpart A—Introduction

2. Section 11.15 is amended by

revising the heading and paragraph

(a)(1) to read as follows:

§ 11.15 What damages may a trustee

recover?

(a) * * *

(1) Damages as determined in

accordance with this part and calculated

based on injuries occurring from the

onset of the release through the recovery

period, less any mitigation of those

injuries by response actions taken or

anticipated, plus any increase in

injuries that are reasonably unavoidable

as a result of response actions taken or

anticipated;

* * * * *

3. Section 11.18 is amended by

revising paragraph (a)(4) and adding a

new paragraph (a)(5) to read as follows:

§ 11.18 Incorporation by reference.

(a) * * *

(4) The CERCLA Type A Natural

Resource Damage Assessment Model for

Coastal and Marine Environments,

Technical Documentation, Volumes I–

VI, dated April 1996, prepared for the

U.S. Department of the Interior by

Applied Science Associates, Inc., A.T.

Kearney, Inc., and Hagler Bailly

Consulting, Inc. (NRDAM/CME

technical document). Interested parties

may obtain a copy of this document

from the National Technical Information

Service, 5285 Port Royal Road,

Springfield, VA 22161; PB96–501788;

ph: (703) 487–4650. Sections 11.34 (a)

(b) and (e), 11.35(a), 11.36(b), 11.40(a),

and 11.42(a), and Appendix II refer to

this document.

(5) The CERCLA Type A Natural

Resource Damage Assessment Model for

Great Lakes Environments, Technical

Documentation, Volumes I–IV, dated

April 1996, prepared for the U.S.

Department of the Interior by Applied

Science Associates, Inc., and Hagler

Bailly Consulting, Inc. (NRDAM/GLE

technical document). Interested parties

may obtain a copy of this document

from the National Technical Information

Service, 5285 Port Royal Road,

Springfield, VA 22161; PB96–501770;

ph: (703) 487–4650. Sections 11.34 (a)

(b) and (e), 11.35(a), 11.36(b), 11.40(a),

and 11.42(a), and Appendix III refer to

this document.

* * * * *

4. Section 11.19 is removed and

reserved.

Subpart C—Assessment Plan Phase

5. Section 11.30 is amended by

revising the heading and paragraphs (a)

and (c)(1)(vi) to read as follows:

§ 11.30 What does the authorized official

do if an assessment is warranted?

(a) If the authorized official

determines during the Preassessment

Phase that an assessment is warranted,

the authorized official must develop a

plan for the assessment of natural

resource damages.

* * * * *

(c) * * *

(1) * * *

(vi) Any other Assessment Plan costs

for activities authorized by §§ 11.30

through 11.38.

* * * * *

6. Section 11.31 is amended by

revising the heading and paragraphs

(a)(1), (b), (c) introductory text, (c)(1),

and (d) to read as follows:

§ 11.31 What does the Assessment Plan

include?

(a) General content and level of detail.

(1) The Assessment Plan must identify

and document the use of all of the type

A and/or type B procedures that will be

performed.

* * * * *

(b) Identification of types of

assessment procedures. The Assessment

Plan must identify whether the

authorized official plans to use a type A

procedure, type B procedures, or a

combination. Sections 11.34 through

11.36 contain standards for deciding

which types of procedures to use. The

Assessment Plan must include a

detailed discussion of how these

standards are met.

(c) Specific requirements for type B

procedures. If the authorized official

plans to use type B procedures, the

Assessment Plan must also include the

following:

(1) The results of the confirmation of

exposure performed under § 11.37;

* * * * *

(d) Specific requirements for type A

procedures. If the authorized official

plans to use a type A procedure, the

Assessment Plan must also contain the

information described in subpart D.

7. Section 11.32 is amended by

revising the heading and paragraph

(c)(1) and adding a new paragraph (f)(3)

to read as follows:

§ 11.32 How does the authorized official

develop the Assessment Plan?

* * * * *

(c) Public involvement in the

Assessment Plan. (1) The authorized

official must make the Assessment Plan

available for review by any identified

potentially responsible parties, other

natural resource trustees, other affected

Federal or State agencies or Indian

tribes, and any other interested member

of the public for a period of at least 30

calendar days, with reasonable

extensions granted as appropriate. The

authorized official may not perform any
20610 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

type B procedures described in the

Assessment Plan until after this review

period.

* * * * *

(f) * * *

(3) Paragraphs (f)(1) and (f)(2) of this

section do not apply to the use of a type

A procedure.

8. Section 11.33 is revised to read as

follows:

§ 11.33 What types of assessment

procedures are available?

There are two types of assessment

procedures:

(a) Type A procedures are simplified

procedures that require minimal field

observation. Subpart D describes the

type A procedures. There are two type

A procedures: a procedure for coastal or

marine environments, which

incorporates the Natural Resource

Damage Assessment Model for Coastal

and Marine Environments, Version 2.4

(NRDAM/CME); and a procedure for

Great Lakes environments, which

incorporates the Natural Resource

Damage Assessment Model for Great

Lakes Environments, Version 1.4

(NRDAM/GLE).

(b) Type B procedures require more

extensive field observation than the type

A procedures. Subpart E describes the

type B procedures.

9. Sections 11.34 and 11.35 are

redesignated as §§ 11.37 and 11.38 and

new §§ 11.34 through 11.36 are added to

read as follows:

§ 11.34 When may the authorized official

use a type A procedure?

The authorized official may use a type

A procedure only if:

(a) The released substance entered an

area covered by the NRDAM/CME or

NRDAM/GLE. Section 3.4, Volume III of

the NRDAM/CME technical document

(incorporated by reference, see § 11.18)

identifies the areas that the NRDAM/

CME covers. Section 6.2, Volume III of

the NRDAM/GLE technical document

(incorporated by reference, see § 11.18)

describes the areas that the NRDAM/

GLE covers;

(b) The NRDAM/CME or NRDAM/

GLE cover the released substance. Table

7.1, Volume I of the NRDAM/CME

technical document lists the substances

that the NRDAM/CME covers. Table 7.1,

Volume I of the NRDAM/GLE technical

document lists the substances that the

NRDAM/GLE covers;

(c) The released substance entered

water at or near the surface;

(d) At the time of the release, winds

did not vary spatially over the area

affected by the release in a way that

would significantly affect the level or

extent of injuries;

(e) The authorized official is not

aware of any reliable evidence that, for

species that are likely to represent a

significant portion of the claim, the

species biomass is significantly lower

than the species biomass assigned by

the NRDAM/CME or the NRDAM/GLE

Tables IV.2.1 through IV.2.115 and

IV.5.1 through IV.5.77, Volume III of the

NRDAM/CME technical document list

the species biomasses in the NRDAM/

CME. Tables III.3.17 through III.3.27 and

III.3.40 through III.3.50, Volume III of

the NRDAM/GLE technical document

list the species biomasses in the

NRDAM/GLE ; and

(f) Subsurface currents either: are not

expected to significantly affect the level

or extent of injuries; or are reasonably

uniform with depth over the water

column in the area affected by the

release.

§ 11.35 How does the authorized official

decide whether to use type A or type B

procedures?

(a) If the authorized official

determines under § 11.34 that a type A

procedure is available, the authorized

official must then decide whether to use

that procedure or use type B procedures.

The authorized official must make this

decision by weighing the difficulty of

collecting site-specific data against the

suitability of the averaged data and

simplifying assumptions in the type A

procedure for the release being assessed.

The authorized official may use type B

procedures if they can be performed at

a reasonable cost and if the increase in

accuracy provided by those procedures

outweighs the increase in assessment

costs. Section 1, Volume I of the

NRDAM/CME technical document

(incorporated by reference, see § 11.18)

lists the simplifying assumptions made

in the NRDAM/CME. Volumes III

through IV of the NRDAM/CME

technical document list the data in the

NRDAM/CME. Section 1, Volume I of

the NRDAM/GLE technical document

(incorporated by reference, see § 11.18)

lists the simplifying assumptions made

in the NRDAM/GLE. Volume III of the

NRDAM/GLE technical document lists

the data in the NRDAM/GLE.

(b) The authorized official must use

type B procedures rather than a type A

procedure whenever a potentially

responsible party:

(1) Submits a written request for use

of type B procedures along with

documentation of the reasons

supporting the request; and

(2) Advances all reasonable costs of

using type B procedures within a time

frame acceptable to the authorized

official.

(c) If there is no available type A

procedure, the authorized official must

use type B procedures to calculate all

damages.

(d) Except as provided in paragraph

(b) of this section, the authorized official

may change the type of procedure used

in light of comments received on the

Assessment Plan. [See § 11.32(e)(2) to

determine if the authorized official must

provide for additional public review.]

However, if the authorized official

decides to use type B procedures in lieu

of a type A procedure, and cannot

confirm exposure under § 11.37, the

authorized official may not then use a

type A procedure.

§ 11.36 May the authorized official use

both type A and type B procedures for the

same release?

(a) The authorized official may use

both a type A procedure and type B

procedures for the same release if:

(1) The type B procedures are costeffective and can be performed at a

reasonable cost;

(2) There is no double recovery; and

(3) The type B procedures are used

only to determine damages for injuries

or compensable values that do not fall

into the categories addressed by the type

A procedure. [Sections 11.14(v) and

11.62 define ‘‘injury.’’ Section

11.83(c)(1) defines ‘‘compensable

value.’’]

(b) The type A procedures address the

following categories of injury and

compensable value:

(1) Direct mortality of species covered

by the NRDAM/CME or NRDAM/GLE

resulting from short-term exposure to

the released substance. Volume IV of the

NRDAM/CME technical document

(incorporated by reference, see § 11.18)

lists the species that the NRDAM/CME

covers. Section 3, Volume III of the

NRDAM/GLE technical document

(incorporated by reference, see § 11.18)

lists the species that the NRDAM/GLE

covers;

(2) Direct loss of production of species

covered by the NRDAM/CME or

NRDAM/GLE resulting from short-term

exposure to the released substance;

(3) Indirect mortality of species

covered by the NRDAM/CME or

NRDAM/GLE resulting from disruption

of the food web by direct mortality or

direct loss of production;

(4) Indirect loss of production of

species covered by the NRDAM/CME or

NRDAM/GLE resulting from disruption

of the food web by direct mortality or

direct loss of production;

(5) Lost assimilative capacity of water

column and sediments;

(6) Lost economic rent for lost

commercial harvests resulting from any
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20611

closures specified by the authorized

official and/or from population losses;

(7) Lost recreational harvests resulting

from any closures specified by the

authorized official and/or from

population losses;

(8) For the type A procedure for

coastal and marine environments, lost

wildlife viewing, resulting from

population losses, by residents of the

States bordering the provinces in which

the population losses occurred. [A

province is one of the geographic areas

delineated in Table 6.1, Volume I of the

NRDAM/CME technical document.] For

the type A procedure for Great Lakes

environments, lost wildlife viewing,

resulting from population losses, by

residents of local areas bordering the

provinces in which the population

losses occurred. [A province is one of

the geographic areas delineated in Table

8.1, Volume I of the NRDAM/GLE

technical document.];

(9) Lost beach visitation due to

closure; and

(10) For the type A procedure for

Great Lakes environments, lost boating

due to closure.

(c) If the authorized official uses both

type A and type B procedures, he or she

must explain in the Assessment Plan

how he or she intends to prevent double

recovery.

(d) When the authorized official uses

type B procedures for injuries not

addressed in a type A procedure, he or

she must follow all of subpart E (which

contains standards for determining and

quantifying injury as well as

determining damages), § 11.31(c)

(which addresses content of the

Assessment Plan), and § 11.37 (which

addresses confirmation of exposure).

When the authorized official uses type

B procedures for compensable values

that are not included in a type A

procedure but that result from injuries

that are addressed in the type A

procedure, he or she need not follow all

of subpart E, § 11.31(c), and § 11.37.

Instead, the authorized official may rely

on the injury predictions of the type A

procedure and simply use the valuation

methodologies authorized by § 11.83(c)

to calculate compensable value. When

using valuation methodologies, the

authorized official must comply with

§ 11.84.

10. Newly designated § 11.37 is

amended by revising the heading and

paragraph (a) to read as follows:

§ 11.37 Must the authorized official

confirm exposure before implementing the

Assessment Plan?

(a) Before including any type B

methodologies in the Assessment Plan,

the authorized official must confirm that

at least one of the natural resources

identified as potentially injured in the

preassessment screen has in fact been

exposed to the released substance.

* * * * *

11. The heading of subpart D is

revised to read as follows:

Subpart D—Type A Procedures

12. Section 11.40 is amended by

revising the heading and paragraph (a),

removing paragraph (b), removing the

heading from paragraph (c), and

redesignating paragraph (c) as paragraph

(b) to read as follows:

§ 11.40 What are type A procedures?

(a) A type A procedure is a

standardized methodology for

performing Injury Determination,

Quantification, and Damage

Determination that requires minimal

field observation. There are two type A

procedures: the type A procedure for

coastal and marine environments; and

the type A procedure for Great Lakes

environments. The type A procedure for

coastal and marine environments

incorporates a computer model called

the Natural Resource Damage

Assessment Model for Coastal and

Marine Environments Version 2.4

(NRDAM/CME). The NRDAM/CME

technical document (incorporated by

reference, see § 11.18) includes and

explains the NRDAM/CME. The type A

procedure for Great Lakes environments

incorporates a computer model called

the Natural Resource Damage

Assessment Model for Great Lakes

Environments Version 1.4 (NRDAM/

GLE). The NRDAM/GLE technical

document (incorporated by reference,

see § 11.18) includes and explains the

NRDAM/GLE. The authorized official

must follow §§ 11.41 through 11.44

when using the type A procedures.

(b) * * *

13. Section 11.41 is revised to read as

follows:

§ 11.41 What data must the authorized

official supply?

(a) The NRDAM/CME and the

NRDAM/GLE require several data

inputs to operate. The authorized

official must develop the following data

inputs:

(1) The identity of the released

substance;

(2) The mass or volume of the

identified substance that was released;

(3) The duration of the release;

(4) The time of the release;

(5) The location of the release;

(6) The wind conditions;

(7) The extent of response actions;

(8) The extent of any closures;

(9) The implicit price deflator; and

(10) For the NRDAM/CME, the

condition of the currents and tides.

(b) The authorized official must

change the data in the NRDAM/CME

and the NRDAM/GLE for the following

parameters if he or she is aware of more

accurate data:

(1) Air temperature;

(2) Water temperature at the surface;

(3) Total suspended sediment

concentration;

(4) Mean settling velocity of

suspended solids; and

(5) Habitat type.

(c)(1) If the release occurred in Alaska

and the authorized official is not aware

of any reliable evidence that ice was

absent from the site of the release, then

he or she must turn on the ice modeling

function. Otherwise, the authorized

official must leave the ice modeling

function off.

(2) If the release occurred in the Great

Lakes and the authorized official is

aware of reliable evidence that ice was

absent from the site of the release, then

he or she must turn off the ice modeling

function.

(d) The authorized official must

develop the data inputs and

modifications and include them in the

Assessment Plan in the format specified

in Appendix II (for the NRDAM/CME)

or Appendix III (for the NRDAM/GLE).

14. New §§ 11.42 through 11.44 are

added to subpart D to read as follows:

§ 11.42 How does the authorized official

apply the NRDAM/CME or NRDAM/GLE?

(a) The authorized official must

perform a preliminary application of the

NRDAM/CME or NRDAM/GLE with the

data inputs and modifications

developed under § 11.41. Volume II of

the NRDAM/CME technical document

(incorporated by reference, see § 11.18)

describes how to apply the NRDAM/

CME. Volume II of the NRDAM/GLE

technical document (incorporated by

reference, see § 11.18) describes how to

apply the NRDAM/GLE. For cases

involving releases of two or more

substances or a release of a mixture of

substances, the authorized official may

only apply the NRDAM/CME or

NRDAM/GLE once using only one of the

substances.

(b) If the preliminary application of

the NRDAM/CME or NRDAM/GLE

indicates damages in excess of

$100,000, then the authorized official

must decide whether to:

(1) Limit the portion of his or her

claim calculated with the type A

procedure to $100,000; or

(2) Compute all damages using type B

procedures.
20612 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

§ 11.43 Can interested parties review the

results of the preliminary application?

After completing the preliminary

application of the NRDAM/CME or

NRDAM/GLE, if the authorized official

decides to continue with the type A

procedure, he or she must issue an

Assessment Plan for public comment as

described in § 11.32. The Assessment

Plan must include the information

described in § 11.31, the data inputs and

modifications developed under § 11.41,

and a summary of the results of the

preliminary application. The

Assessment Plan must also identify a

contact from whom a complete copy of

the printout of the preliminary

application can be obtained.

§ 11.44 What does the authorized official

do after the close of the comment period?

(a) The authorized official must

carefully review all comments received

on the Assessment Plan, provide

substantive responses to all comments,

and modify the Plan as appropriate. [See

§ 11.32(e)(2) to determine if the

authorized official must provide for

additional public review.]

(b) If, after reviewing the public

comments, the authorized official

decides to continue with the type A

procedure, he or she must then perform

a final application of the NRDAM/CME

or NRDAM/GLE, using final data inputs

and modifications based on § 11.41 and

any reliable information received during

the public review and comment period.

(c) After completing the final

application of the NRDAM/CME or

NRDAM/GLE, the authorized official

must prepare a Report of Assessment.

The Report of Assessment must include

the printed output from the final

application as well as the Preassessment

Screen Determination and the

Assessment Plan.

(d) If the authorized official is aware

of reliable evidence that a private party

has recovered damages for commercial

harvests lost as a result of the release,

the authorized official must eliminate

from the claim any damages for such

lost harvests that are included in the

lost economic rent calculated by the

NRDAM/CME or NRDAM/GLE.

(e) If the authorized official is aware

of reliable evidence that the NRDAM/

CME or NRDAM/GLE application covers

resources beyond his or her trustee

jurisdiction, the authorized official must

either:

(1) Have the other authorized

official(s) who do have trustee

jurisdiction over those resources join in

the type A assessment; or

(2) Eliminate any damages for those

resources from the claim for damages.

(f) If the final application of the

NRDAM/CME or NRDAM/GLE, adjusted

as needed under paragraphs (d) and (e),

calculates damages in excess of

$100,000, then the authorized official

must limit the portion of his or her

claim calculated with the type A

procedure to $100,000.

(g) After preparing the Report of

Assessment, the authorized official must

follow the steps described in subpart F.

15. The heading of subpart E is

revised to read as follows:

Subpart E—Type B Procedures

16. Section 11.73 is amended by

revising the second sentence of

paragraph (a) to read as follows:

§ 11.73 Quantification phase-resource

recoverability analysis

(a) * * * The time estimated for

recovery or any lesser period of time as

determined in the Assessment Plan

must be used as the recovery period for

purposes of § 11.38 and the Damage

Determination phase, §§ 11.80 through

11.84.

* * * * *

Subpart F—Post-Assessment Phase

17. Section 11.90 is amended by

revising the heading, paragraphs (a) and

(b), and the first sentence of paragraph

(c) as follows:

§ 11.90 What documentation must the

authorized official prepare after completing

the assessment?

(a) At the conclusion of an

assessment, the authorized official must

prepare a Report of Assessment that

consists of the Preassessment Screen

Determination, the Assessment Plan,

and the information specified in

paragraphs (b) and (c) of this section as

applicable.

(b) When the authorized official has

used a type A procedure, the Report of

Assessment must include the

information specified in subpart D.

(c) When the authorized official has

used type B procedures, the Report of

Assessment must include all

documentation supporting the

determinations required in the Injury

Determination phase, the Quantification

phase, and the Damage Determination

phase, and specifically including the

test results of any and all methodologies

performed in these phases. * * *

18. Section 11.91 is amended by

revising the heading and by removing

the first sentence of paragraph (a) and

inserting three new sentences in its

place to read as follows:

§ 11.91 How does the authorized official

seek recovery of the assessed damages

from the potentially responsible party?

(a) At the conclusion of the

assessment, the authorized official must

present to the potentially responsible

party a demand in writing for the

damages determined in accordance with

this part and the reasonable cost of the

assessment. [See § 11.92(b) to determine

how the authorized official must adjust

damages if he or she plans to place

recovered funds in a non-interestbearing account.] The authorized official

must deliver the demand in a manner

that establishes the date of receipt.

* * *

* * * * *

19. New Appendices II and III are

added to read as follows:

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 § 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
Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations 20613

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 northernand southern-most latitude, and the easternand 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:

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 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
20614 Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and Regulations

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.

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 § 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 § 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:

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.

Dated: April 25, 1996.

Bonnie R. Cohen,

Assistant Secretary—Policy, Management,

and Budget.

[FR Doc. 96–10747 Filed 5–6–96; 8:45 am]

BILLING CODE 4310–RG–P