TM 5-814-8
oxygen in a stream to a point where other aquatic
(10) Suspended solids produce a variety of
life cannot, exist.
detrimental effects. Turbidity and its associated
problems are increased by suspended solids addi-
(3) Toxic materials and heavy metals such as
cadmium, lead, mercury and zinc may severely
tion to a stream. The high organic content of
inhibit or kill organisms in the receiving waters.
some suspended solids exerts a high BOD on the
Many of these substances may concentrate in
water and creates oxygen depletion problems.
aquatic organisms. Small concentrations in the
Sedimentation of suspended solids results in an
stream can be stored up in aquatic animals (bioac-
accumulation of solids on the bottom of the
cumulation) to extremely high levels which may
receiving body of water. This sludge bank may
eventually be passed to man through the food
alter the habitat of the bottom dwelling (benthic)
chain. Occurrence of this type of toxic migration
organisms sufficiently to decrease or eliminate
has been documented for several toxic compounds
some species populations. Additionally, biological
such as polychlorinated biphenyls (PCB's).
activity within the sludge bank may produce
(4) The major problem associated with addi-
gases which lift masses of decomposing sludge to
tions of color and turbidity to natural waters is
the surface creating an unsightly and malodorous
that these parameters reduce light penetration
situation.
into the water. This, in turn, decreases the rate of
(11) Discharge of wastewaters having temper-
photosynthesis and causes a decrease in the
atures significantly higher than the receiving
stream population of algae and aquatic plants.
stream may elevate the temperature of the
The food supply for animals feeding on algae and
stream. This will subsequently decrease the dis-
aquatic plants is then reduced, possibly resulting
solved oxygen content, since oxygen is less solu-
in growth inhibition or death of the higher forms
ble in water at higher temperatures. Increased
of life.
biological activity resulting from higher tempera-
(5) Nutrients, although necessary to aquatic
tures further accelerates oxygen depletion. Ther-
life, may, when present at too high a concentra-
mal pollution can therefore result in suffocation
tion, cause algal blooms (where algae reproduce
of aquatic life.
extremely quickly, covering water surfaces in
c. Ocean disposal. Within environmental con-
large floating colonies). Although algae produce
straints either barge transport or an outfall pipe
oxygen in sunlight by photosynthesis, at night
can be used for ocean disposal of industrial
they utilize oxygen in much the same manner as
w a s t e s . The former is primarily used for the --
other microorganisms do. When they reach a
disposal of low volume concentrated wastewater
harmful level, the lake or reservoir is considered
whereas the latter is more suitable for large
eutrophic. This is offensive in recreational facili-
volumes of diluted wastewater.
ties and may inhibit future uses of impounded
(1) Developing an ocean outfall solution for a
waters unless treatment is provided.
particular waste should include the following
(6) Refractory materials, such as some syn-
steps:
thetic detergents, may cause foaming which is
--Define the beneficial uses of the marine
aesthetically displeasing.
waters at the disposal site and its vicin-
(7) Oil and floating materials are aesthetically
ity. Beneficial uses may include commer-
undesirable, typically high in BOD, and may
cial fishing, marine recreation, navigation,
suffocate aquatic life by blanketing gills, leaves
fishery propagation and migration, and
and other oxygen transfer surfaces. Floating
industrial use.
substances may also have a capping effect on the
--Define the water quality criteria pertinent
stream decreasing or destroying the natural
to the relevant beneficial uses. Areas of
stream reaeration abilities.
concern include public health, aesthetic
(8) Acids and alkalis may shock (rapid or
nuisances, toxicity to marine biota, stim-
localized change in conditions which is detrimen-
tal to aquatic life) receiving streams if the pH of
ulation of planktonic blooms, and oxygen
the waste is sufficiently different from the exist-
depletion.
ing pH in the stream. Most localities require that
--Define the oceanographic characteristics
discharges to natural waters be neutralized to
of the disposal site. This includes water
within a pH range of 6.0 to 9.0. Some restrictions
circulation patterns, currents and disper-
are even more stringent,
sion, density and temperature profiles,
(9) Substances resulting in atmospheric
and submarine topography.
odors, such as sulfides, are aesthetically unappeal-
Design wastewater disposal system to
ing and should be eliminated before discharge.
meet required quality criteria.
5-12
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