MIL-HDBK-1005/16
Choices depend on severity of freezing, ice cover, and available
sunshine. Check lagoon size for detention time as listed.
For facility layout with multiple ponds in series or
parallel, limit the first stage pond to 40 lb/day/acre
(45 kilogram per day per hectare [kg/day/ha]) for odor control
in areas where the average winter air temperature is 32F (0C)
or less. For areas where the average winter air temperature is
50F (10C) or greater, the first cell in a series of cells may
be loaded as high as 90 lb/day/acre (100 kg/day/ha). Proportion
the remainder of the total required area based on BOD5 loading
equally among remaining cells.
Table 13
Facultative Lagoon Sizing Criteria
Minimum BOD Loading in
Climate
lb/day/acre (kg/day/ha)
Detention (d)
Minimum
Maximum
Cold (extended
15 (17)
20 (22)
150 - 180
ice cover)
Temperate
20 (22)
50 (56)
40 - 150
(short ice cover)
Subtropical
50 (56)
100 (112)
10 - 40
and tropical
(no ice cover)
7.3.1.1
Depth. Provide an operating depth of 6 feet
(1.8 m),
allowing varying depth between 3 to 8 feet (0.9 to 2.4
m) for
flow and load variations and insect and weed control.
The ponds
will slowly accumulate solids over time, so convenient
access
should be provided so equipment can dredge the ponds.
This
normally is not required more frequently than every 10
years.
7.3.1.2
Design Equations. Refer to EPA-625/1-83-015 for
discussion and application of rational design equations.
7.3.2
Location. Locate the lagoon at least 0.25 mile
(0.4 km) downwind from populated areas if the pond receives ice
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