The 1976 outbreak of Hog Cholera in New Jersey: An application of geology to a biological emergency

Hog cholera is a highly contagious virus disease of swine. Since 1962, a Hog Cholera Eradication Program has replaced vaccination as the control mechanism in the U.S. Because the cholera agent requires a live host to thrive, quarantine and herd depopulation are ordered at every U.S. outbreak. The results have been positive and dramatic.The presence of hog cholera was confirmed in Gloucester County, New Jersey, on February 26, 1976. A cooperative State-Federal task force was mobilized to contain and eliminate the infection. Burial would be the disposal technique. For the first time a geologist was requested to augment outbreak control, with responsibility to pinpoint safe burial sites for thousands of animals. USDA emergency policy and procedures limited the options of the assisting geologist, but basic geologic judgments sufficed during appraisals of burial sites. Ultimately, 10 sites were needed and used; other locations proposed during the course of the outbreak were judged hydrogeologically unsuitable and were therefore rejected. Each excavation was sited to minimize potential impact on local aquifers, chiefly by maintaining maximum separation from the water table and by prudent siting within the hydrogeology of the outbreak area.From the first positive confirmation to the end of the active outbreak, a period of four weeks, 15,741 swine totaling over 1 million kg were destroyed and buried. The resulting indemnity was just under $3 million. Because of effective cooperative action during the New Jersey incident, geologic appraisal during large U.S. livestock depopulations now promises to become standard procedure.