A large animal farm can generate a large amount of animal sewage. One way this may be managed is to place it in a large pond where it accumulates.
Large pig farms are the most common locations for a manure lagoon but they may be associated with any concentrated animal feeding operation (CAFO).
The typical manure lagoon consists of a large, shallow depression which may be lined by a polyethylene liner. A liquid slurry is easier to pump into the lagoon but has a high water content. A large open area helps to water in the slurry to evaporate and more solid components to settle..
Uses of manure lagoon:
(1) methane gas generation
(2) fertilizer
Hazards of a manure lagoon:
(1) accumulation of pathogenic bacteria or parasites
(2) accumulation of antibiotic-resistant bacteria
(3) anaerobic liquid which can be toxic to fish if it leaks into lakes or streams
(4) smell
(5) methane gas which can ignite if it concentrates
(6) other chemicals such as ammonia and hydrogen sulfide
(7) flood potential if a retaining wall is breached
(8) fecal contamination of ground water if it leaks into water table
Release of the lagoon waste can occur if:
(1) there is flooding or a heavy rain
(2) earthquake
(3) break in liner
(4) collapse of a retaining wall
(5) overflow from excessive inflow
