Trends of Mercury Emission Drivers for Southern Florida Janja D. Husar and Rudolf B. Husar Prepared for: State of Florida Department of Environmental Protection May 2001

Background Elevated mercury levels were found in the upper levels of the food chain in southern Florida. Recently, a significant decline of mercury in birds was observed. The cause of the sharp decline is not well understood.

Objectives: Estimate the major emission driving activities (emission drivers) that cause the emissions of mercury to the atmosphere over southern Florida. Combine the emission drivers with emission factors (contributed by others) to estimate the atmospheric emission trends of mercury over the 20 years.

Major source types of atmospheric mercury Fossil fuel combustion Municipal waste incineration Medical waste incineration Miscellaneous sources

Coal Consumption in Power Plants Power Plant Average/Month The coal consumption in power plants has remained constant during There is about 10% seasonal variation in the coal consumption, summer peaked. Most of the utility coal consumption was in the Tampa-Orlando corridor.

Oil Consumption in Power Plants The oil consumption in power plants between has varied by about factor of two from one year to another. No clear trend is evident. There is about factor of 2-3 seasonal variation with a strong summer peak. Most (>80%) of the utility oil consumption was in southern Florida Power Plant Average/Month

Natural Gas Consumption in Power Plants The natural gas consumption in power plants between has varied by about 50% from one year to another. The peak consumption was in There is about factor of 2 seasonal variation with a strong summer peak. Over >60% of the utility natural gas consumption was in South Florida Power Plant Average/Month

Southern Florida Municipal Solid Waste (MSW) Combustion The total capacity to burn MSW in Florida is about 7,000,000 t/yr. There are 13 Waste To Energy (WTE) facilities in the state, 12 located in coastal zones of southern Florida. Source: Florida DEP County MSW summary sheets Since 1989 there was an increase of waste combustion, followed by a sharp decline since 1995.

Biomedical Waste Generation (2000) Biomedical waste generation in Florida, in year 2000 was ~50,000 t/yr (DEP, FL, 2000). Small generators (<25lb/month) contribute about 5% of the medical waste. Larger generators (14,000 facilities) contribute 95% of the medical waste.

Medical Waste Incineration There are two previous mercury emission estimates for years 1990 (KBN, 1992), and 1996 (RMB, 1998). In 1990 in Dade and Broward counties >50,000 t/yr medical waste was incinerated in 33 facilities. In 1996 in Dade and Broward counties <20,000 t/yr medical waste was incinerated in only 9 facilities. In 1999 <8,000t/yr was incinerated only in 2 facilities. Change in medical waste handling or reporting?

Commercial Biomedical Waste Treatment Facilities Since 1990 there was a significant decline in number of hospitals that incinerate their own medical waste. Commercial biomedical waste treatment facilities took over the handling of medical waste. Commercial methods used are: –Incineration –Autoclave –Electron Beam In southern Florida incineration commercial facilities are located in only 2 counties: –Polk –Pinnelas

Summary (progress report) Fossil fuel consumption over southern Florida can be estimated with reasonable certainty (+/ %??). Municipal waste combustion data since 1989 are available, but need cross checking. Data prior to 1989 are not readily available. Medical waste incineration data are accessible through AORs; since 1990 the available data indicate a factor of 10 decline of medical waste incineration: the trend data need significant further verification. The combination of emission drivers and emission factors (supplied by others) as well as the examination of the resulting emission trends is to be conducted in June 2001.