FLOOD08883

• County: Statewide
• Basin: Statewide
• Title: Federal Register EPA Guidelines for Specification of Disposal Sites for Dredged or Fill Material
• Date: 12/24/1980
• Prepared By: EPA
• Floodplain - Doc Type: Educational/Technical/Reference Information

Federal Register / Vol. 45. No. 249 / Wednesday. December 24. 1980 / Rules and Regulations 85351

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effects, objectionable tastes and orlors.
and other problems.

f 230.23 Current patterns and water
circulation.

(8) Current patterns and water
circulation are the physical movements
of water in the aquatic ecosystem.
Currents and circulation respond to
natural forces as modified by basin
shape and cover. physical and chemical
characteristics of water strata and
masses, and energy dissipating factors.
(b) Possible loss of environmental
characteristics and values: The
discharge of dredged or fill material can
modify current patterns and water
circulation by obstructing flow, changing
the direction or velocity of water flow.
changing the direction or velocity of
water flow and circulation. or otherwise
changing the dimensions of a water
body. As a result. adverse changes can
occur in: location. structure. and
dynamics of aqua tic communities;
shoreline and substrate erosion and
depositon rates: the deposition of
suspended particulates: the rate and
extent of mixing of dissolved and
suspended r.omponents of the water
body; and water stratification.

~ 230.24 Normal water fluctuations.

{a) Normal water fluctuations in a
natural aquatic system consist of daily.
seasonal. and annual tidal and flood
fluctuations in water level. Biological
and physical components of such a
system are either attuned to or
characterized by these periodic water
fluctuations.
(b) Possible loss of environmental
characteristics and values: The .
disc:harge of dredged or fill material can
alter the normal water-level fluctuation
pallern of an area. resulting in
prolonged peri cds of inundation.
exaggerated extremes of high and low
\\'ater. or a SIalic. nonflucluating water
level. Such \....i:der level modifications
m2)' change salinity palterns. alter
erosit'n cr sedimentation rates.
aggravate water temperature extremes.
amI upset the nutrient and dissolved
ox}"gen balance of the aquatic
ecosystem. In addition. these
modifIcations can alter or destroy
communities and populations of aquatic
animals and vegetation, induce
populations of nuisance organisms.
modify habitat. reduce food supplies.
restflct movement of aquatic fauna.
destroy spawning areas. and change
adjacent. upstream. and downstream
areas.

~ 230.25 Sollnl1y grodlon1a.

(a) Salinity gradients form where salt
water from the ocean meets and mixes
with fresh water from land.
[b) Possible loss of environmental
characteristics and values: Obstructions
which divert or restrict flow of either
fresh or salt water may change existing
salinity gradients. For example. partial
blocking of the entrance to an estuary or
river mouth that significantly restricts
the movement of the salt water into and
out of that area can effectively lower the
volume of salt water available for
mixing within that estuary. The
downstream migration of the salinity
gradient can occur. displacing the.
maximum sedimentation zone and
requiring salinity-dependent aquatic
biota to adjust to the new conditions.
move to new locations if possible. or
perish. In the freshwater zone. discharge
operations in the upstream regions can
have equally adverse impacts. A
significant reduction in the volume of
fresh water moving into an estuary
below that which is considered normal
can affect the location and type of
mixing thereby changing the
characteristic salinity patterns. The
resulting changed circulation pattern
can cause the upstream migration of the
salinity gradient displacing the maximim
sedimentation zone. -This migration may
affect those organisms that are adapted
to freshwater environments. It may also
affect municipal water supplies.

Note.-Possible actions to minimize
ad\'erse impacts regarding site characteristics
can be found in Subpart H.

Subpart D-Potentlallmpacts on
Biological CharacterlaUca oflhe
Aquatic Ecosystem

'Note.-The impacts described in this
subpart should be considered in making the
factual determinations and the findings of
complli:lnce or non-compliance in Subptlrl B.

~ 230,30 Threatened and endangered
species.

(a) An endangered species is a plant
or animal in danger of extinction
throughout all or a significant portion of
its range. A threatened species is one in
danger of becoming an endangered
species in the foreseeable future
throughout all or a significant portion of
its range. Listings of threatened and
endangered species as well as critical
habitats are maintained by sam....
individual States and by the U.S. Fish
and V~'ildlife Service of the Department
of the Interior (codified annually at 50
CFR ! 17.11). The Department of
Commerce has authority over some
threatened and endangered marine
mammals, fish and reptiles.

(b] Possible loss of values: The major
potential impacts on threatened or
endangered species from the discharge
of dredged or fill material include:
(1) Covering or otherwise directly
killing species;
(2) The impairment or destructioo of
habitat to which these species are
limited. Elements of the aquatic habitat
which are particularly crucial to the
continued survival of some threatened
or endangered species include adequate
good quality water. spawning and
maturation areas. nesting areas.
protective cover, adequate and reliable
food supply. and resting areas for
migratory species. Each of these
elements can be .adversely affected by
changes in either the normal water
conditions for clarity, chemical content.
nutrient balance. dissolved oxygen, pH.
temperature. salinity. current patterns.
circulation and fluctuation. or the
physical removal of habitat and
(3) Facilitating incompatible activities.
(c) Where consultation with the
Secretary of the Interior occurs under
Section 7 of the Endangered Species
Act. the conclusions of the Secretary
concerning the impact(s) of the
discharge on threatened and endangered
species and their habitat shall be -
considered final.

~ 230.31 Fish. crustaceans. mollusks and
other aquatic organisms In the food web.
(a) Aquatic organisms in the food web
include. but are not limited to. finfish.
crustaceans, mollusks, insects. annelids.
planktonic organisms. and the plants
and animals on which they feed and
depend upon for their needs. All forms
and life stages of an organism.
throughout its geographic range. are
included in this category.
[b) Possible loss of values: The
discharge of dredged or fill material can
variously affect populations of fish,
crustaceans. mollusks and other food
web organisms through the release of
contaminants which adversely affect
adults, juveniles. larvae, or eggs. or
result in the establishment or
proliferation of an undesirable
competitive species of plant or animal at
the expense of the desired resident
species. Suspended particulates settling
on attached or bur.ed eggs can smother
the eggs by limiting or sealing off their
exposure to oxygenated water.
Discharge of dredged and fill material
may result in the debilitation or death of
sedentary organisms by smothering.
exposure to chemical contaminants in
dissolved or suspended form. exposure
to high levels of suspended particulates.
reduction in food supply. or alteration of
the substrate upon which they are
dependent. Mollusks are psrticularly