Odor Control 16
Lagoon Loading Rate
In order to minimize odor production anaerobic lagoons in South
Carolina should be sized based on a loading rate of 3.43 pounds
of volatile solids per 1,000 cubic feet of treatment volume. Appropriate
storage space must also be provided for the accumulation of sludge,
all wastewater, and precipitation. Treatment and sludge storage
volumes are given in the following table in terms of surface area
required for a 6 ft depth and equivalent total. The tabulated
values assume 10 years of storage for sludge.
Treatent and Sludge Storage Volume Parameters for Anaerobic Swine
Lagoons in South Carolina (SCS Standard 359).
Type of
Swine Facility |
Required Surface Area
for a 6 ft. Treatment
square feet / animal | Equivalent
Depth Volume
cubic feet / animal |
| Gestation | 70 / sow |
420 / sow |
| Farrowing | 83 / sow & litter
| 498 / sow & litter |
| Feeders (20 - 45 lb) | 25 / pig
| 150 / pig |
| Growing - Finishing (45 to 220 lb) | 50 / hog
| 300 / hog |
Avoid Slug Loading
A lagoon should be loaded on a continual basis. Slug loading,
(i.e. large amounts of manure relative to the biological capacity
of the lagoon) causes a rapid increase in volatile acids thereby
lowering the pH and creating a high odor level. If slug loading
cannot be avoided, add a covered surge holding tank which can
be slug loaded and then emptied gradually into the lagoon.
Manage Solids
The required treatment volume can not be provided if solids are allowed
to build up in the lagon. At this point the earthen basin ceases to
function as an anaerobic treatment lagoon and becomes a large uncovered
storage pond. Odor production can be high. The sludge must be removed
and applied to crop, pasture, or forest land to restore the required
treatment volume. Remove a portion of the sludge layer every 2 to 3
years to avoid excessive sludge buildup.
Plan Sludge Utilization Area in Advance
Many swine producers are surprised to find that the sludge in the bottom
of the lagoon is rich in nitrogen, phosphorous, and potassium. The land
that normally receives lagoon effluent will not be sufficient for proper
spreading of the sludge. Additional crop, or forest land will be needed
in order to spread sludge at agronomic rates.
