Animal Waste

Several times a day, hog waste is flushed with water from the hog house, carried through pipes, and dumped into an open-air pit, called a waste lagoon. Waste is held in the lagoons for up to six months, where it receives minimal treatment. Older waste lagoons are not lined -- they are simply holes dug into the earth. Newer waste lagoons are required to use a clay liner to reduce the amount of waste which can leak out of the pit.

In the photo above, hog waste is stored in open air lagoons. Note white input pipes which bring waste from hog houses.
As of October 1998, North Carolina has over 4600 waste lagoons. These can threaten people and the environment in major ways:

Waste lagoons produce gases that contribute to pollution. Bacteria starts to break down the hog waste sitting in the lagoon, and produces a number of gases including ammonia (a form of nitrogen) and methane. Ammonia and methane are volatile, which means they turn into gases and rise out of the waste into the air. What goes up must come down, and most of this ammonia and methane eventually fall back to earth somewhere in the coastal plain of North Carolina or beyond.

Waste lagoons house toxic sludge that may pose serious clean up problems. In the waste lagoon, solids and liquids separate. The solids form sludge that sits on the lagoon bottom for 10 to 20 years, until it is removed and land-applied. The solids contain several compounds, including heavy metals (copper and zinc that are toxic to plants and animals), and phosphorus. As of October 1998, North Carolina has 643 "inactive" waste lagoons. These "inactive" lagoons contain toxic sludge and are awaiting clean out.

Waste lagoons can leak into the ground, contaminating groundwater and drinking wells. Waste lagoons are actually allowed by law to leak, so long as the waste lagoon surface does not drop by more than 0.036 inches a day. This may not sound like a large amount, but over the course of a year, a single three acre waste lagoon could leak up to a million gallons of waste. Studies show that shallow groundwater drinking wells below hog and chicken farms have major increases in nitrates, a form of nitrogen (Showers, 1998). High levels of nitrates are dangerous to humans, especially pregnant women and babies, and can cause abortions and "blue baby syndrome" (a disease affecting the blood's ability to absorb oxygen).

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