[Code of Federal Regulations]

[Title 40, Volume 24]

[Revised as of July 1, 2006]

From the U.S. Government Printing Office via GPO Access

[CITE: 40CFR230.11]



[Page 262-264]

 

                   TITLE 40--PROTECTION OF ENVIRONMENT

 

         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)

 

PART 230_SECTION 404(b)(1) GUIDELINES FOR SPECIFICATION OF DISPOSAL SITES 

FOR DREDGED OR FILL MATERIAL--Table of Contents

 

                Subpart B_Compliance With the Guidelines

 

Sec.  230.11  Factual determinations.



    The permitting authority shall determine in writing the potential 

short-term or long-term effects of a proposed discharge of dredged or 

fill material on the physical, chemical, and biological components of 

the aquatic environment in light of subparts C through F. Such factual 

determinations shall be used in Sec.  230.12 in making findings of 

compliance or non-compliance with the restrictions on discharge in Sec.  

230.10. The evaluation and testing procedures described in Sec.  230.60 

and Sec.  230.61 of subpart G shall be used as necessary to make, and 

shall be described in, such determination. The determinations of effects 

of each proposed discharge shall include the following:

    (a) Physical substrate determinations. Determine the nature and 

degree of effect that the proposed discharge will have, individually and 

cumulatively, on the characteristics of the substrate at the proposed 

disposal site. Consideration shall be given to the similarity in 

particle size, shape, and degree of compaction of the material proposed 

for discharge and the material constituting the substrate at the 

disposal site, and any potential changes in substrate elevation and 

bottom contours, including changes outside of the disposal site which 

may occur as a result of erosion, slumpage, or other movement of the 

discharged material. The duration and physical extent of substrate 

changes shall also be considered. The possible loss of environmental 

values (Sec.  230.20) and actions to minimize impact (subpart H) shall 

also be considered in making these determinations. Potential changes in 

substrate elevation and bottom contours shall be predicted on the basis 

of the proposed method, volume, location, and rate of discharge, as well 

as on the individual and combined effects of current patterns, water 

circulation, wind and wave action, and other physical factors that may 

af fect the movement of the discharged material.

    (b) Water circulation, fluctuation, and salinity determinations. 

Determine the nature and degree of effect that the proposed discharge 

will have individually and cumulatively on water, current patterns, 

circulation including downstream flows, and normal water fluctuation. 

Consideration shall be given to water chemistry, salinity, clarity, 

color, odor, taste, dissolved gas levels, temperature, nutrients, and 

eutrophication plus other appropriate characteristics. Consideration 

shall also be given to the potential diversion or obstruction of flow, 

alterations of bottom contours, or other significant changes in the 

hydrologic regime. Additional consideration of the possible loss of 

environmental values (Sec. Sec.  230.23 through 230.25) and actions to 

minimize impacts (subpart H), shall be used in



[[Page 263]]



making these determinations. Potential significant effects on the 

current patterns, water circulation, normal water fluctuation and 

salinity shall be evaluated on the basis of the proposed method, volume, 

location, and rate of discharge.

    (c) Suspended particulate/turbidity determinations. Determine the 

nature and degree of effect that the proposed discharge will have, 

individually and cumulatively, in terms of potential changes in the 

kinds and concentrations of suspended particulate/turbidity in the 

vicinity of the disposal site. Consideration shall be given to the grain 

size of the material proposed for discharge, the shape and size of the 

plume of suspended particulates, the duration of the discharge and 

resulting plume and whether or not the potential changes will cause 

violations of applicable water quality standards. Consideration should 

also be given to the possible loss of environmental values (Sec.  

230.21) and to actions for minimizing impacts (subpart H). Consideration 

shall include the proposed method, volume, location, and rate of 

discharge, as well as the individual and combined effects of current 

patterns, water circulation and fluctuations, wind and wave action, and 

other physical factors on the movement of suspended par ticulates.

    (d) Contaminant determinations. Determine the degree to which the 

material proposed for discharge will introduce, relocate, or increase 

contaminants. This determination shall consider the material to be 

discharged, the aquatic environment at the proposed disposal site, and 

the availability of contaminants.

    (e) Aquatic ecosystem and organism determinations. Determine the 

nature and degree of effect that the proposed discharge will have, both 

individually and cumulatively, on the structure and function of the 

aquatic ecosystem and organisms. Consideration shall be given to the 

effect at the proposed disposal site of potential changes in substrate 

characteristics and elevation, water or substrate chemistry, nutrients, 

currents, circulation, fluctuation, and salinity, on the recolonization 

and existence of indigenous aquatic organisms or communities. Possible 

loss of environmental values (Sec.  230.31), and actions to minimize 

impacts (subpart H) shall be examined. Tests as described in Sec.  

230.61 (Evaluation and Testing), may be required to provide information 

on the effect of the discharge material on communities or populations of 

organisms expected to be exposed to it.

    (f) Proposed disposal site determinations. (1) Each disposal site 

shall be specified through the application of these Guidelines. The 

mixing zone shall be confined to the smallest practicable zone within 

each specified disposal site that is consistent with the type of 

dispersion determined to be appropriate by the application of these 

Guidelines. In a few special cases under unique environmental 

conditions, where there is adequate justification to show that 

widespread dispersion by natural means will result in no significantly 

adverse environmental effects, the discharged material may be intended 

to be spread naturally in a very thin layer over a large area of the 

substrate rather than be contained within the disposal site.

    (2) The permitting authority and the Regional Administrator shall 

consider the following factors in determining the acceptability of a 

proposed mixing zone:

    (i) Depth of water at the disposal site;

    (ii) Current velocity, direction, and variability at the disposal 

site;

    (iii) Degree of turbulence;

    (iv) Stratification attributable to causes such as obstructions, 

salinity or density profiles at the disposal site;

    (v) Discharge vessel speed and direction, if appropriate;

    (vi) Rate of discharge;

    (vii) Ambient concentration of constituents of interest;

    (viii) Dredged material characteristics, particularly concentrations 

of constituents, amount of material, type of material (sand, silt, clay, 

etc.) and settling velocities;

    (ix) Number of discharge actions per unit of time;

    (x) Other factors of the disposal site that affect the rates and 

patterns of mixing.

    (g) Determination of cumulative effects on the aquatic ecosystem. 

(1) Cumulative impacts are the changes in an aquatic



[[Page 264]]



ecosystem that are attributable to the collective effect of a number of 

individual discharges of dredged or fill material. Although the impact 

of a particular discharge may constitute a minor change in itself, the 

cumulative effect of numerous such piecemeal changes can result in a 

major impairment of the water resources and interfere with the 

productivity and water quality of existing aquatic ecosystems.

    (2) Cumulative effects attributable to the discharge of dredged or 

fill material in waters of the United States should be predicted to the 

extent reasonable and practical. The permitting authority shall collect 

information and solicit information from other sources about the 

cumulative impacts on the aquatic ecosystem. This information shall be 

documented and considered during the decision-making process concerning 

the evaluation of individual permit applications, the issuance of a 

General permit, and monitoring and enforcement of existing permits.

    (h) Determination of secondary effects on the aquatic ecosystem. (1) 

Secondary effects are effects on an aquatic ecosystem that are 

associated with a discharge of dredged or fill materials, but do not 

result from the actual placement of the dredged or fill material. 

Information about secondary effects on aquatic ecosystems shall be 

considered prior to the time final section 404 action is taken by 

permitting authorities.

    (2) Some examples of secondary effects on an aquatic ecosystem are 

fluctuating water levels in an impoundment and downstream associated 

with the operation of a dam, septic tank leaching and surface runoff 

from residential or commercial developments on fill, and leachate and 

runoff from a sanitary landfill located in waters of the U.S. Activities 

to be conducted on fast land created by the discharge of dredged or fill 

material in waters of the United States may have secondary impacts 

within those waters which should be considered in evaluating the impact 

of creating those fast lands.