TM 5-814-3/AFM 88-11, Volume III
x
=
a+b
(eq 4-1)
Where
x
=
Total flow to sewage plant
a
=
Flow from population (effective population 100 gpcd capacity factor
b
=
Infiltration + industrial wastewater + stormwater (4 dry-weather flow)
4-7. Wastewater characteristics.
a. Normal sewage. The wastewater at existing facilities will be analyzed to determine the characteristics and
constituents as required in paragraph 4-5. Analytical methods will be as given in the current edition of American
Public Health Association (APHA) publication, Standard Methods for the Examination of Water and
Wastewater and as approved by the Environmental Protection Agency (EPA). For treatment facilities at new
installations which will not generate any unusual waste, the treatment will be for normal domestic waste with
the following analysis:
pH
7.0 std units
Total solids
720 mg/L
Total volatile solids
420 mg/L
Suspended solids
200 mg/L
Settleable solids
4 ml/L
BOD
200 mg/L
Total nitrogen
30 mg/L
Ammonia nitrogen
15 mg/L
Oils and grease
100 mg/L
Phosphorus
10 mg/L
Chloride
50 mg/L
Concentrations are presented above in milligrams per liter; which is equivalent to parts per million (ppm). These
values represent an average waste and therefore should be used only where detailed analysis is not available.
When the water supply analysis for the installation is known, the above analysis will be modified to reflect the
normal changes to constituents in water as it arrives at the wastewater treatment plant. Changes will be as
follows:
P in water supply + 12 mg/L = P in plant influent;
Cl in water supply + 8 mg/L = Cl in plant influent;
b. Nondomestic loading. Nondomestic wastes are stormwater; infiltration, and industrial contributions to
sewage flow. Stormwater and infiltration waste loadings can be determined by analyses for the constituents of
normal sewage, as presented in the previous section. For these types of flows, the major loading factors are
suspended solids, biochemical oxygen demand, and coliform bacteria.
c. Industrial loading. Industrial waste loadings can also be characterized to a large extent by normal sewage
parameters. However; industrial waste contains contaminants not generally found in domestic sewage and is
more more variable than domestic sewage. This is evident in terms of pH, biochemical oxygen demand, chemical
oxygen demand, oil and grease, and suspended solids; other analyses (e.g., heavy metals, thermal loading, and
dissolved chemicals) may also be necessary to characterize an industrial waste fully. Each industrial wastewater
must be characterized individually to determine any and all effects of treatment processes.
4-5
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