COMPARATIVE EFFECTS OF POULTRY AND SWINE WASTE LAGOON SPILLS ON THE QUALITY OF RECEIVING STREAMWATERS

During July 1995, a poultry waste lagoon ruptured in Duylin County, No rth Carolina, sending 32.6 million L of chicken waste effluent into a nearby creek and the Northeast Cape Fear River. In August 1995 a breac h of a hog waste lagoon released approximately 7.6 million L of waste into a system of blackwater creeks in Brunswick County, North Carolina . The poultry waste spill occurred under high rainfall-high river now conditions, while the swine waste lagoon spill occurred during dry con ditions. Both spills caused high turbidity and low dissolved oxygen (D O) in receiving waters, and DO levels in the Northeast Cape Fear River displaced a ''sag curve'' 10 d after the poultry waste spill, reachin g a minimum of 1.0 mg L-1 90 km downstream. Both spills delivered high N loads to receiving waters (maxima of 92.1 mg L-1 from the poultry s pill and 47.0 mg L-1 from the swine waste spill). Phosphorous concentr ations reached 6.0 and 11.5 mg L-1 in receiving waters of the poultry and swine waste spills, respectively. Dense phytoplankton blooms (>100 mu g chlorophyll a L-1) were measured in the blackwater creeks after the swine spill. High fecal coliform concentrations were delivered by both spills, and concentrations of the pathogenic bacterium Clostridiu m perfringens ranged up to 40 000 colony-forming units (CFU) mL(-1) in the receiving waters after the poultry spill. In 1995 and 1996 more t han 30 animal waster lagoon breaches, overtoppings, and inundations we re reported in North Carolina, demonstrating the major pollution poten tial of these treatment systems.