Plant C slaughtered and processed swine. Samples tested with negative results included swine blood, raw well water, wastewater from sewer lines serving a spice-kitchen workers' locker room and a kill-floor workers' locker room, supernatant fluid from process wastewater, and packaged luncheon meat. The rate of intestinal infection of animals at the time of slaughter was found to be quite high. All the 10 fecal samples taken from holding pen floors on Monday, when the animals had been together for three days were positive. Three of these viruses were identified as reoviruses and the remaining seven were enteroviruses, of which six replicated only in swine cells, but one also replicated in monkey cells. A small, heat-stable agent that could not be sustained beyond two passages in swine cells was detected in sediment from process wastewater, in de-watered primary sludge, and in raw and cooked meat scraps. Follow-up sampling of swine feces and intestinal contents at the plant revealed a high incidence of enteroviruses, some of which replicated only in swine cells, while others replicated in both swine and monkey cells.