Atmospheric Environment 42 (2008) 3291–3300 Characterizing ammonia emissions from swine farms in eastern North Carolina: Reduction of emissions from water-holding structures at two candidate superior technologies for waste treatment Viney P. Aneja a,Ã , S. Pal Arya a , Ian C. Rumsey a , D-S. Kim a , K.S. Bajwa a , C.M. Williams b a Department of Marine, Earth and Atmospheric Sciences, North Carolina State University, Raleigh, NC 27695-8208, USA b Animal and Poultry Waste Management Center, North Carolina State University, Raleigh, NC 27695-7608, USA Received 18 September 2006; received in revised form 11 July 2007; accepted 13 August 2007 Abstract Program OPEN (Odor, Pathogens, and Emissions of Nitrogen) was an integrated study of the emissions of ammonia (NH 3 ), odor and odorants, and pathogens from potential environmentally superior technologies (ESTs) for swine facilities in eastern North Carolina. This paper, as part of program OPEN, focuses on quantifying emissions of NH 3 from water- holding structures at two of the best ESTs and compares them with the projected emissions from two conventional lagoon and spray technologies (LSTs). The evaluated ESTs are: (1) Super Soils at Goshen Ridge; and (2) Environmental Technologies at Red Hill. The water-holding structures for these two ESTs contained no conventional anaerobic lagoon. A dynamic flow-through chamber was used to measure NH 3 fluxes from the water-holding structures at both the ESTs and at the conventional LST farms. In order to compare the emissions from the water-holding structures at the ESTs with those from the lagoons at the conventional sites under similar conditions, a statistical-observational model for lagoon NH 3 emissions was used. A mass-balance approach was used to quantify the emissions. All emissions were normalized by nitrogen-excretion rates. The percentage reductions relative to the conventional lagoons were calculated for the two ESTs. Results showed substantial reductions in NH 3 emissions at both ESTs. Super Soils had reductions of 94.7% for the warm season and 99.0% for the cool season. Environmental Technologies had slightly larger reductions of 99.4% and 99.98% for the cool and warm season, respectively. As a result of such large reductions in ammonia emissions, both technologies meet the criteria to be classified as ESTs for ammonia emissions. r 2007 Elsevier Ltd. All rights reserved. Keywords: Ammonia emissions; Ammonia flux; Water-holding structures; Environmentally superior technologies (ESTs); Lagoon and spray technologies (LSTs) 1. Introduction Atmospheric ammonia (NH 3 ) is a very important alkaline constituent, and has a significant influence ARTICLE IN PRESS www.elsevier.com/locate/atmosenv 1352-2310/$ - see front matter r 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.atmosenv.2007.08.037 Ã Corresponding author. Tel.: +1 919 515 7808; fax: +1 919 515 7802. E-mail address: viney_aneja@ncsu.edu (V.P. Aneja).