Impact/Purpose:

During August 1995, EPA and the State of Florida conducted a field study in which sample were collected from multiple ambient sites located in and near the Everglades and 3 sources (2 incinerators and a Portland cement operation). Extensive meteorological data was also collected. Analysis of these samples will be completed and the data analyzed to evaluate the performance of dispersion and receptor models in describing the impact of Hg emissions from the above sources in South Florida. Receptor modeling will include EPA's Chemical Mass Balance-7 model and a modified RAMS model will be employed for dispersion modeling. The data base developed as a result of these analyses will provide new information on the quantity and chemical form of Hg emitted by incinerators and will provide source signatures of some of the suspected major sources of Hg in South Florida. These models will use the observational data to apportion and characterize the impacts of these sources on the receptor sites and to estimate the transport of these emissions to the Everglades.

Description:

In 1995, the South Florida Atmospheric Mercury Monitoring Study was established to investigate several likely sources of Hg, as well as transport and deposition mechanisms. Field operations began on August 10, 1995, and ran continuously through September 6, 1995. Source sampling was conducted at three facilities suspected of emitting Hg. The source sampling component investigated the chemical form and magnitude of Hg emissions from a resource recovery incinerator, a medical waste incinerator, and a coal-fired Portland cement kiln. In-stack measurements also included PM2.5, elemental and organic carbon, trace elements, and trace gases. Field measurements were conducted at a network of five surface sites. Four surface sites were located in Dade County and one in Broward County. The monitor locations were chosen to represent a marine background site (Adams Key), three urban sites located near mercury emitting sources (Davie, Miami Springs and Dade County), and one site located west of the urban sites adjacent to the Everglades (Thompson Park). Day and night air samples were collected for PM2.5, elemental and organic carbon, trace elements, and trace gases. Extensive meteorological data were collected. This report focuses largely on data completeness and the spatial-temporal variability of ambient concentration data. Although the data presented are only a portion of that collected under the overall study, it constitutes a valuable source of information on the chemical composition of the South Florida atmosphere with respect to Hg and other related pollutants.

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