Land Treatment of Food Processing Wastewaters

At Paris, Tex., a surface filtration system is constructed on land that is relatively impervious and will not permit high infiltration rates. This is a new concept of spray irrigation by overland flow wherein the wastewater is spread in a thin sheet to have a good interaction zone with soil humus. The microbiological activity of the soil organisms purifies the water to achieve 99% BOD reduction in a travel of approx 225 ft. The preferred slopes are approx 2–6%. At Sumter, S. Car., there is a 5–7-ft layer of sandy soil with a high rate of infiltration. This is underlain by a relatively dense substrata. The water after pretreatment is sprayed through the sprinkler system, falls on the land which has been planted to special grasses, and infiltrates through the ground and is picked up by the underground perforated pipe and conducted to the final polishing pond and savanna. This pond has become a wildlife sanctuary harboring many kinds of fish, wild egrets, blue herons, ducks, geese, coots, and other wildlife.