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.
Facultative Lagoon Sizing Criteria
Minimum BOD Loading in
150 - 180
40 - 150
(short ice cover)
10 - 40
(no ice cover)
Depth. Provide an operating depth of 6 feet
allowing varying depth between 3 to 8 feet (0.9 to 2.4
flow and load variations and insect and weed control.
will slowly accumulate solids over time, so convenient
should be provided so equipment can dredge the ponds.
normally is not required more frequently than every 10
Design Equations. Refer to EPA-625/1-83-015 for
discussion and application of rational design equations.
Location. Locate the lagoon at least 0.25 mile
(0.4 km) downwind from populated areas if the pond receives ice