Chesapeake Bay Foundation: Nitrogen Emissions at Chesapeake Bay

Executive Summary

A detailed ammonia emissions factors for poultry will be conducted. The 2015 Census of Agriculture data will be used to obtain the number of broilers, chickens (laying hens, young and mature pullets) animals per county for the Delmarva Peninsula (USDA 2015). The Carnegie Mellon University (CMU) Ammonia Emissions Model Version 3 (Davidson, 2006) will be used to compare calculated emission rates (based on the US EPA latest National Emissions Inventory and published values) with model estimates (Aneja et al., 2012).

We propose to use the U.S. EPA’s regulatory model, AERMOD, to simulate ammonia dispersion and deposition from an existing or proposed new facility. AERMOD is a widely accepted local and mesoscale dispersion and deposition model, which is also recommended by the U.S. EPA for regulatory applications. We can also model the combined contributions of all the poultry facilities spread over the desired area of Delmarva Peninsula to the Chesapeake Bay. We will choose an appropriate horizontal grid size, depending on the source and the receptor areas of interest. We will work with the CBF staff to identify the desired modeling scenarios available, the meteorological/climatological data as input to the model and model assumptions. We will provide results of of modeling scenarios including, but not limited to, annual, monthly and daily estimates of dry and wet deposition concentration and deposition patterns and transport distances and estimates of annual nitrogen deposition to nearby waterways (Chesapeake Bay). Based on these modeling results, we will make recommendations for a cost effective monitoring approach that could be used to estimate deposition of nitrogen/ammonia from new poultry houses to local bodies of water.

The sampling strategy will be arrived at in consultations with The Chesapeake Bay Foundation. However, emissions of NH3 may be monitored for 1 month during each of the four predominant seasons at the poultry houses (Blunden et al., 2008). The monitoring setup, methodology, and data calculation will be as reported by Aneja et al. (2008b). Temperatures (barn locations and ambient), relative humidity, and room static pressures will also be measured. A weather station and ultrasonic anemometers (Model 81000 R.M. Young) will be used to collect wind direction and velocity data. Concentrations of NH3 will be analyzed using a chemiluminesence continuous ammonia analyzers (TECO 17C Ammonia Analyzer). An air conditioned mobile laboratory will be deployed at the sampling location. It will house all the measurement instruments. The QA/QC program for the project will ensure that all data collected be complete, representative, accurate, precise, and comparable. It will aim to minimize the loss of data due to out-of-control conditions. Where possible, we will follow guidelines for the establishment, operation, maintenance, and quality assurance testing per US EPA specifications. For calibration of ammonia analyzer, ammonia certified standard gas will be used.4