The MET-Team    

EPA Targets Mercury Emissions From Power Plants

Electric Power is a driver of our nation's economy and critical in maintaining our high quality of life. Coal-fired power plants, however have been targeted for additional emissions reductions including sulfur dioxide, nitrogen oxides, and mercury.

Coal-fired power plants are targeted for mercury reductions to help reduce the airborne levels of mercury that may eventually be deposited in water or on land. Mercury concentrations in the air are low and of little direct concern. However, once mercury enters water, biological processes transform it into methyl mercury that bioaccumulates in fish and other animals that eat fish. Human exposure to mercury occurs primarily through consumption of contaminated fish.

EPA Initiatives

On March 15, 2005, EPA issued the Clean Air Mercury Rule (CAMR) to reduce and permanently cap mercury emissions from coal-fired power plants. This rule, in combination with EPA's Clean Air Interstate Rule (CAIR), will significantly reduce mercury emissions in this country. When fully implemented, these rules will reduce mercury emissions from coal-fired power plants by nearly 70%. For more information on EPA initiatives, see www.epa.gov/mercury.

Test Method

40 CFR, part 75-Continuous Emission Monitoring, Appendix K entitled "Quality Assurance and Operating Procedures for Sorbent Trap Monitoring Systems" provides for the measurement of total vapor-phase mercury, which represents the sum of elemental and oxidized forms of mercury.

With this method, known volumes of flue gas are extracted from a duct through paired spiked sorbent traps at a flow rate of 200-600 ml/min. The sampling period can vary from 30 minutes to several days in duration. After sampling, the sorbent is acid leached and the resulting leachate is analyzed by cold vapor atomic fluorescence spectrometry (CVAFS). Alternatively, analysis can be performed using cold vapor atomic absorption spectrometry (CVAAS).

40 CFR, part 75-Continuous Emission Monitoring, Appendix K issues the following cautions:

• Sorbent traps must be obtained from a reliable source such that high quality assurance and control ensure consistent reliability.
• Persons using this method should have a thorough working knowledge of other related sampling methods.

The Total Solution for Sorbent Trap Mercury Emissions Testing

Only the MET-Team offers an alliance of technical expertise from Clean Air Engineering, CONSOL Energy, and SKC Inc. to provide the sampling media, stack sampling systems, analysis, and services that make your sampling job easy and accurate.