ML092010055
| ML092010055 | |
| Person / Time | |
|---|---|
| Site: | Kewaunee  |
| Issue date: | 08/01/2008 |
| From: | Office of Public Affairs |
| To: | |
| References | |
| Download: ML092010055 (4) | |
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Factsheet on Rule to Control Mercury Emissions from Coal-Fired Power Plants Wisconsin Department of Natural Resources Bureau of Air Management Revised August 2008 Why is controlling mercury emissions in Wisconsin important?
Health effects experts worldwide have identified the reduction of mercury exposures as a major public health goal. All of Wisconsin's inland waters are under a general fish consumption advisory that recommends that people, particularly pregnant women and young children, limit the number of some fish species they eat because of elevated mercury levels. The Wisconsin Department of Health Services, federal governmental organizations and institutions have identified women of child-bearing age, infants and children as the populations at greatest risk from elevated mercury exposure. These risks include developmental effects such as lower performance on language, attention and memory tests and adverse effects in vision and motor functions. Recent research has identified mercury effects in the immune system and a potential role of mercury exposure in elevating the risks of heart attacks in adults.
Currently, mercury emissions from coal-fired power plants in Wisconsin account for over 60 percent of the annual mercury air emissions from state sources. However, the relative contribution from these power plants will increase to 86 percent of the annual mercury air emissions in Wisconsin when the ERCO chlor-alkali facility in Port Edwards eliminates its mercury cell technology by the end of 2009.
What sources does the mercury emissions reduction rule regulate?
The Department of Natural Resources (DNR) rule will regulate emissions from coal-fired power plants (electric generating units or EGUs) from seven utilities in Wisconsin. The rule covers forty-three units operated by Dairyland Power Cooperative, Madison Gas & Electric Company, Manitowoc Public Utilities, Northern States Power of Wisconsin, We Energies, Wisconsin Power & Light Company and Wisconsin Public Service
Corporation.
What does the rule do?
Under the rule, the state's large coal-fired power plants (those with a nameplate capacity of 150 Megawatts (MW) and greater) must achieve a 90% mercury emission reduction through one of two compliance paths. Small coal-fired power plants (> 25 MW and <
150 MW) must reduce their mercury emissions to a level defined as Best Available Control Technology (BACT). Wisconsin's four major utilities, Dairyland Power Cooperative, We Energies, Wisconsin Power & Light Company and Wisconsin Public Service Corporation, must reduce their mercury emissions 40% by January 1, 2010. This mercury reduction requirement is retained from the current state mercury rule.
Mercury emissions expected from the application of this adopted rule will reduce coal-fired power plant mercury emissions from 3,200 pounds per year to 500 pounds of mercury air emissions annually.
Large Power Plants By January 1, 2015 existing large coal-fired power plants must achieve a 90% mercury reduction or limit the concentration of mercury emissions to 0.0080 pounds of mercury
per gigawatt-hour. Compliance must be dem onstrated annually on a unit-by-unit basis. However, large units under common ownership or control can average to meet the mercury emission standard.
1 Large Power Plants Multipollutant Option A multipollutant alternative for large power plants requires nitrogen oxides (NO x) and sulfur dioxide (SO
- 2) reductions beyond those currently required by federal and state regulations, as well as attaining a delayed 90% mercury emission reduction standard. Owners and operators must designate which large units will follow the multipollutant option by December 31, 2010. Large units that are not designated for the multipollutant option will, by default, be required to achieve the large power plant mercury emission standard of a 90% reduction by 2015.
Under the multipollutant option, affected power plants must achieve a nitrogen oxides (NO x) emission standard of 0.07 pounds of NO x per million BTU and a sulfur dioxide (SO 2) emission standard of 0.10 pounds of SO 2 per million BTU by January 1, 2015. An additional six years to achieve a 90% mercury emission standard is provided to large power plants included in the multipollutant reduction approach. Compliance must be demonstrated annually on a unit-by-unit basis. However, large units under common ownership or control can average to meet the NO x , SO 2, or mercury emission standard.
An interim mercury reduction goal is established that targets January 1, 2015 to achieve a 70% mercury reduction or limiting the concentration of mercury emissions to 0.0190 pounds of mercury per gigawatt-hour. Beginning January 1, 2018 an 80% mercury reduction or limiting the concentration of mercury emissions to 0.0130 pounds of
mercury per gigawatt-hour must be achieved.
By January 1, 2021 a 90% mercury reduction or limiting the concentration of mercury emissions to 0.0080 pounds of mercury per gigawatt-hour is required. The percent reduction standard is measured from the mercury content in the coal combusted.
Early Mercury Emission Reduction Credits A large coal-fired power plant may request certification of early mercury emission reductions. Early emissions that qualify are: 1) reductions beyond 40% of the baseline requirement in 2010-2014; and 2) plants that select the multipollutant compliance pathway that achieve reductions beyond the 70% reduction requirement in 2015-2017 and the 80% reduction requirement in 2018-2020. These early emission reduction credits may be used to meet a portion of the annual allowable mercury emissions for the 70%, 80% and 90% emission limitations in the multipollutant compliance pathway.
Electric Reliability Compliance Extension A compliance extension, not to exceed two years from 2015, for large power plants to meet the mercury only or the multipollutant option may be granted if it is demonstrated that electric reliability could be disrupted without an extension. This extension option acknowledges that there may be circumstances where scheduling installation of control equipment to meet the requirements may take additional time. The Department would consult with the Public Service Commission on any electric reliability compliance
extension request.
Small Power Plants By January 1, 2015 existing small coal-fired power plants (those with a nameplate capacity greater than 25 MW but less than 150 MW) must achieve a level of mercury emissions defined as BACT. Owners or operators would propose BACT for small units by June 30, 2011 and the Department must respond within six months of a complete 2
proposal. Owners or operators have the option to decide if units in this size range are placed in the large unit compliance pathway.
New Power Plants After the effective date of the rule, new coal-fired power plants must achieve Maximum Achievable Control Technology (MACT) to reduce emissions of hazardous air pollutants, including mercury, as required under section 112 of the federal Clean Air Act. In no case shall the permitted mercury reduction be less than 90% removal of mercury from coal combusted.
What are the mercury emission reductions achieved under the rule?
If all large power plants elected to achieve a 90% mercury reduction by 2015, total mercury emissions would be approximately 536 pounds per year. If all large power plants elected to follow the multipollutant option, mercury emissions would still be reduced to 536 pounds however, this is not achieved until 2021. Substantial reductions in sulfur dioxide and nitrogen oxide emissions would however be achieved by 2015 under the multipollutant option. These reductions of pollutants other than mercury have significant health and welfare benefits to Wisconsin and address other critical air quality concerns including fine particles, haze, and ground level ozone.
What will the adopted rule achieve that the current rule does not?
The adopted rule will achieve more emission reductions, affect more coal-fired power plants in the state, and require that new coal-fired power plants meet a stringent mercury control technology standard. It also provides greater flexibility in achieving mercury reductions and includes a multipollutant option that provides regulatory certainty to electric utilities to cost effectively meet current and future air quality responsibilities.
How does the repeal of the federal Clean Air Mercury Rule (CAMR) affect this rule?
Now that federal CAMR is vacated, there is no federal mercury emission limit for existing coal-fired power plants.
What are the costs of the rule?
The costs of mercury control technology applicable to coal-fired power plants found in Wisconsin are reasonable and cost-effective. Technologies are commercially available and are capable of achieving 90% reduction. For example, the cost of sorbent injection with existing particulate control equipment is expected to range from 0.04 to 0.15 cents/kilowatt hour for all power plant sizes and a Toxecon system costs in the range of 0.12 to 0.24 cents/kilowatt hour for large power plants, with both approaches achieving 90% mercury removal. Similar control efficiencies can be achieved at lower cost when mercury control is integrated into a multipollutant control system.
Multipollutant approaches are preferred because environmental and public health benefits can be achieved at lower costs. The mercury portion of multi-pollutant control costs could be as low as 0.04 to 0.1 cents/kilowatt hour, while achieving mercury removal efficiencies in the range of 80% to 95%.
The cost of the rule is estimated by evaluating the type of control installations and costs that may be needed at individual plants to meet the proposed rule requirements. The resulting average cost across all of the affected power plants is expected to range from 0.06 to 0.14 cents/ kilowatt hour. The costs of sorbent injection for small plants and the mercury portion of multipollutant control costs for large plants will be at the lower end of 3
this range. For an average household (8,900 kilowatt hours per year), this range of electricity costs is $ 5 to $ 60 annually.
What is the timeline for the rule?
A public hearing was held on April 7, 2008. The DNR responded to comments and the Natural Resources Board adopted the revised rule on June 25, 2008. The rule is now under legislative review.
FOR MORE INFORMATION, CONTACT: Jon Heinrich, DNR Bureau of Air Management, (608) 267-7547 Publication AM-392 REV 8/2008 4