MERCURY: Air Emissions and Proposed Utility Rules

Indiana Department of

Environmental Management

September 2004

Mercury and Health Effects

• Mercury in Indiana’s environment is a public health and environmental concern. Mercury—especially in its organic form, methylmercury—can affect the central nervous system of adults and children.

• The primary route of human exposure to methylmercury is dietary, and unborn children are as much as 10 times more susceptible than adults to methylmercury’s detrimental effects.

• Mercury has been detected in nearly all fish-tissue samples collected in Indiana since 1983, often prompting health officials to issue advisories that warn about human consumption of these fish.

Mercury and Air Emissions

• Precipitation (wet deposition) is the primary mechanism for transporting airborne gaseous or particulate mercury from the atmosphere to surface water and land.

• Mercury in the atmosphere can be from manmade sources (coal-fired power plants, municipal incinerators, industrial boilers) or from natural sources (forest fires, geologic formations, volcanoes).

• Manmade sources of mercury emissions to the atmosphere have been implicated for causing the increased concentrations of methylmercury found in fish.

• Mercury is a global pollutant.

Mercury Emissions in Indiana

• 2002 emissions: 9745 lbs. ( 4.9 tpy)

• Breakdown by source category– Coal utilities 4398 lbs.– Other point sources 4920 lbs.– Area sources 426 lbs.

Note: Other point sources include electric arc furnaces, cement kilns and foundries.

IDEM/USGS Mercury Monitoring Program

• Monitoring began at four wet deposition sites in Indiana in 2001, and a fifth site plus dry deposition sites were added in 2003. The goals were:

– to measure base-line concentrations and deposition rates for mercury prior to the start of new regulatory controls

– to use the monitoring data to help calculate a Total Maximum Daily Load (TMDL) for mercury in selected watersheds

– to evaluate progress on reducing mercury emissions; and

– to identify future needs for protecting human health and wildlife from mercury exposure.

• Sites were chosen to represent rural, urban, and potential transport areas, and areas potentially impacted by large power plants and industrial sources.

Mercury Monitoring Sites

Findings

• Full report due in late 2004

• Preliminary data show higher values in spring and summer, lower in fall and winter.

• Values do not vary greatly from site to site.

• Mercury deposition may be influenced by mercury emissions near the monitoring station.

Mercury Deposition and Emissions

Indiana’s Mercury Efforts

• Numerous statewide, free mercury collection programs

• Numerous thermometer exchanges

• Outreach to the dental profession regarding use of mercury

• State law that bans the use of mercury in schools and certain consumer products

EPA’s Proposed Utility Rule

• Clean Air Act requires EPA to consider regulating hazardous air pollutants, including mercury, from power plants.

• In 2001, USEPA found that mercury and nickel from power plants poses a public health risk.

• After extensive study, EPA proposed a rule for public comment on January 30, 2004.

• The proposed rule has generated a significant response, including substantial opposition.

• EPA extended original 90-day public comment period until June 29, 2004. EPA must issue a final rule by March 2005, per court order.

EPA’s Proposed Rule

The proposed rule applies to plants > 25 MW and has two options

Option 1:

• applies technology-based emission limits applicable to all affected plants

• would reduce emissions nationally by 14 tons (29%) by 2007, from 48 to 34 tpy

• no cap on emissions

EPA’s Proposed Rule

Option 2• Market-based cap and trade program• Caps applied in two phases:

– 2010 - amount of cap to be decided– 2018 - 15 tpy cap (70% reduction)

• States would allocate allowances from a state “budget” to plants on a lbs/year basis

• plants may install controls or purchase allowances

How will power plants monitor their mercury emissions?

• Fuel analysis and mass balance calculations can be used to estimate emissions– EPA used this methodology to develop the

mercury inventory for the proposed rule

• Continuous emission monitors for mercury are being developed– Many expect the technology to catch up with the

rulemaking and be available by the compliance date

Multipollutant Legislation Proposals Clear Skies Jeffords Carper Chaffee (2002) (2002) (2002) (2002)

Mercury 26 tpy in 5 tpy in 24 tpy in 24 tpy inCap 2010; 15 2008 2008, unit 2008; 7.5

tpy in cap of tpy in 2018 50% Hg 2012, unit

in coal; in cap of2012, unit 30% Hgcap of in coal30%

Other Pollutants SO2 SO2 SO2 SO2

NOx NOx, CO NOx, CO NOx, CO

Issues raised by Indiana and others

• EPA’s options may be legally vulnerable; federal legislation is preferable, addressing multiple pollutants from these sources

• Rule is not fuel neutral; it favors western coal over midwestern coal

• Option 1 emission limits appear higher than what EGUs can achieve; Option 2 cap and trade program could create mercury “hot spots”

• EPA proposed only to regulate mercury and nickel but should continue to study chromium, cadmium and arsenic

Mercury Reduction Technologies

• Selective Catalytic Reduction (SCR)

– converts Hg to removable (oxidized) form, which can be removed by FGD

– $80/kW

• Flue Gas Desulfurization (FGD)

– removes oxidized Hg by absorbing it in a lime slurry

– $159/kW for 700 mw; $541/kW for 100 mw

• Activated Carbon Injection (ACI)

– absorbs Hg on activated carbon particles, then removed by electrostatic precipitator or fabric filter (avail. 2010)

– $15/kW (costs will vary depending on size, operation)

Potential Control Technology for Other HAP

• Some of the controls for the Clean Air Interstate rule and the mercury rule will address emissions of other toxics

• Baghouses and FGDs will control some species of chromium, cadmium and arsenic

• Sorbent injection, combined with a baghouse, may control others

• Since these HAP have both gas and PM phases, there is no one-size-fits-all control technology

Next Steps for Indiana

• States must adopt rules at least as stringent as EPA’s once federal rule is final

• Citizens Petition filed with Indiana Air Pollution Control Board in June 2004 asking board to hold public hearings and begin state rule

Next Steps for Indiana

• Workgroup process will commence this month, in anticipation of state rulemaking

• Monthly meetings to share and discuss information on topics relevant to future rulemaking– Health and environmental impacts – Technology– Costs and benefits

Next Steps for Indiana

• Process open to all interested parties

• IDEM welcomes suggestions for resource materials and/or experts

Next Steps for Indiana

• Air Board has scheduled a public hearing on the citizen’s petition for the October 6 Board meeting

• Additional hearings may be scheduled• IDEM contact: Susan Bem

317-233-5697

sbem@dem.state.in.us www.in.gov/idem/air/