TM 5-814-8
waters. Before proceeding with combined treat-
used are aerated lagoons, rough trickling filters,
and rotating biological contactors. Examples of
ment of industrial and domestic wastes, several
factors should be considered.
pretreatment methods employed at military in-
(1.) Verification of waste compatibility. Non-
stallations before discharge to municipal sewers
are:
compatible industrial discharges can be identified
based upon physical and chemical wastewater
--Screens used for lint collection in laun-
parameters which could damage or make inopera-
dries.
tive the sewage treatment facilities. Industrial
--Removal of oil and grease from wash
discharges can reduce the biochemical reaction
rack wastes.
rates or decrease the sludge settling velocity for
--Sedimentation of solids from wash rack
biological treatment systems. Sludge handling
wastes.
problems commonly result from poor settleability
--Gravity separation of oils and wastes
a n d dewaterability of combined industrial/
from motor pool maintenance facilities.
Dilution in surface waterways. Discharge of
municipal sludges. Additionally, toxic compounds,
b.
such as heavy metals, may render the municipal
wastewaters to surface waterways is the most
plant's sludge unacceptable for common disposal
common ultimate disposal method. Both the loca-
.
methods.
tion of discharge point and the type of dispersion
(2) Loading variations. The contaminant con-
mechanism are important for protecting water
centrations of industrial wastes are usually much
quality. A properly designed subsurface disper-
more variable than that of domestic wastes.
sion system will allow maximum utilization of the
receiving water assimilative capacity.
Variations in the amount or type of the waste
generated can significantly impact the municipal
(1) Federal, State and local governments have
placed restrictions on wastewater discharge qual-
plant operation and performance. Batch processes
or changes in production methods result in or-
ity in order to control the detrimental effects of
ganic, hydraulic, and toxic loading variations
contaminants as described in chapter 2. These
which domestic systems have difficulty anticipat-
restrictions may require a certain type of treat-
ing and responding to.
ment system be used, or they may s p e c i f y
(3) Pretreatment technologies. The applicable
concentration limits on certain parameters regard-
pretreatment technologies can only be defined
less of the treatment system used to obtain these.
after a comprehensive assessment of the waste
Typically, the quality of the receiving stream or
characteristics, discharge limitations and consid-
body of water is taken into consideration along
eration of alternative generation and treatment
with the intended use of the water following the
techniques. Occasionally, non-compatible waste
wastewater discharge. Each state has classified
components c a n b e e l i m i n a t e d b y p r o c e s s
its major streams and bodies of water according
changes. Frequently, production or maintenance
to their own set of use classifications. Table 5-3
schedules can be adjusted to minimize discharges
lists some typical classifications and the associ-
or reduce the impact on municipal plants during
ated quality criteria and required treatment meth-
switching to new products or operations. Exam-
ods for each one. The regulations involved in
ples of in-plant and end-of-pipe techniques are
water quality control are discussed in chapter 4.
presented in table 5-2 for removal of potentially
(2) Of the various pollutants discharged to
non-compatible materials in industrial discharges.
surface waterways, oxygen-depleting compounds
(a) Selection of the pretreatment technol-
have received the most attention. These com-
ogy should also include consideration of reducing
pounds are primarily soluble organics, the dis-
the amount and concentration of compatible pol-
charge of which may be extremely damaging to
lutants. Such consideration can frequently result
the health of the receiving stream. Soluble organ-
in a substantial reduction in the sewer use for
ics are used as food by microorganisms. Microor-
industrial discharges. Installation of aerated la-
ganisms exist almost everywhere in our world
goons or anaerobic pretreatment systems can also
and most microorganisms utilize oxygen for respi-
result in significant savings. Biological systems
ration. Discharge of large quantities of organic
can be used to reduce waste loads discharged to a
physical-chemical treatment system.
material results in increased microorganism
(b) The most commonly used physical/
growth and oxygen consumption. Thus, the in-
creased organism activity resulting from d i s -
chemical pretreatment methods are screening,
charge of soluble organics exerts a "biochemical
emulsion breaking, oil/water separation, sedimen-
oxygen demand (BOD) on the receiving strewn.
tation, equalization, and neutralization. Biological
This natural phenomenon may deplete dissolved
pretreatment methods which are most commonly
5-9
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