Source Identification of Ammonia Inputs to the Wastewater Treatment Holding Pond at International Paper Franklin Mill

While nitrogen is an essential nutrient in aquatic systems, elevated levels of nitrogen can be fatal to many aquatic organisms including fish and other organisms that are in the river. Elevated levels of ammonia have been recently (2001-2002) detected in the water released from a wastewater treatment system holding pond at International Paper Franklin, Virginia and are a concern for the receiving system. The elevated ammonia concentrations observed in previous years were not observed in 2003, due likely to increased precipitation and the occurrence of a major hurricane (Hurricane Isabel) during the sampling period that may have influenced the observations. Sediment, vegetation and water column were studied in the holding pond from April to November 2003 and compared to a reference pond to determine the major contributors of ammonia to the treatment pond and whether recent changes in vegetation may have contributed to the elevated ammonia concentrations. Approximately 85% of the nitrogen in the ponds is in the sediment, 10% contained in the vegetation and Phragmities spp. adding ammonia to the sediment through the roots and the detritus which can then be transported into the water column. Besides the sediment, the Phragmities spp. represents the dominant source of nitrogen in the pond and senescence, death and decomposition in the water and on the surface of the sediment could result in substantial input of nitrogen into D-pond. The Lemna spp. fronds buildup at a boom located at the discharge point of D-pond and deprive some fronds from light causing them to die and decompose and release concentrations ammonia into the D-pond water column near the regulatory sampling point. Ammonia is contributed to the water column from the sediment and the vegetation in the pond. D-pond is substantially undersaturated with dissolved oxygen which likely inhibits conversion of ammonia to nitrate