Sullivan Environmental's Fumigant Emissions Modeling System (FEMS)

Sullivan Environmental developed the Fumigant Emissions Modeling System (FEMS), software that utilizes Monte Carlo simulations to more accurately predict airborne exposures to agricultural fumigants. This system manages the initiation of an application, calculates emission rates over time, and incorporates weather conditions as variables. 

It is designed to integrate with EPA models ISCST3, CALPUFF5, and CALPUFF6 (which offer sub-hourly capabilities) to assist in fumigation processes. The FEMS system received review and approval from the EPA Science Advisory Panel. 

Additionally, a primary objective in creating the FEMS software was to establish a user-friendly platform that integrates the ISCST3, CALPUFF5, and CALPUFF6 models, aiding users in predicting near-field effects of pesticide applications in agricultural areas nationwide. See this link for additional background information on EPA regulatory models.  

The model’s output assists in estimating buffer zones based on predicted concentration levels concerning health-based regulatory thresholds. More information about the FEMS system is available by contacting Sullivan Environmental.

Additionally, the Fumigant Emissions Modeling System (FEMS) structures to simulate between 200 and 100,000 years of operation in each model run.  Furthermore, this allows for precise consideration of uncertainties in both emission and weather data.  Emission distribution formulation uses a land method to generate confidence intervals for natural log-normal medians. 

 

For various geographic locations reflecting agricultural areas, uncertainties in wind direction, speed, and atmospheric stability model the same.  This is based on the emissions distribution and user-selected options. In every scenario, a probability density function is established using expert judgment methods, valuable when direct data for defining probabilities is limited.

 

The application probability function can indicate how frequently applications occur annually and the expected interval between them. Users can also incorporate a fraction of the maximum application rate for reduced application rates per acre. 

 

Additionally, there are options for application types, including standard rectangular and circular configurations. This information is thoroughly accessed in the FEMS Users Guide. Contact Sullivan Environmental for a copy of the Fumigant Emissions Modeling System.