Environmental Compliance
TVA’s role in regional air quality
TVA has spent more than $4.4 billion to reduce emissions of sulfur dioxide (SO2) and nitrogen oxides (NOX) and will spend another $1.3 billion on announced and ongoing projects. Expenditures for emission control equipment were $411 million in 2004 and $202 million in 2005.
In May 2005, TVA broke ground on the construction of a scrubber to further reduce SO2 at Bull Run Fossil Plant in east Tennessee. This is TVA’s eighth scrubber, and its construction further demonstrates that TVA is a national leader in the installation and operation of emission control equipment.
TVA’s financial investments and efforts have produced results in emission reductions. Over the past decade, TVA has contributed substantially to regional air quality improvements, as evidenced by the Change in Regional Utility Emissions charts below. Emissions of SO2 in some southeastern states have been increasing, yet TVA has significantly reduced its SO2 emissions in its service territory, as well as its NOX emissions.
TVA's Clean Air Progress
|
In March 2005, the Environmental Protection Agency (EPA) issued the Clean Air Interstate Rule (CAIR), which sets targets for reducing utility emissions of SO2 and NOX. The rule is intended to help counties in the eastern U.S. meet new EPA standards for ozone and fine particle emissions. By 2015, the targets call for a 73 percent reduction in sulfur dioxide and a 61 percent reduction in nitrogen oxides below 2003 levels. These goals will require all utilities in the region to undertake the kinds of emission reduction efforts that TVA has been carrying out for some time.
Change in annual regional utility emissions,
|
| Nitrogen oxides |
|
| Click charts for data. |
The new demands imposed by CAIR will be a challenge for TVA and other utilities and will most likely put severe strains on the region’s material and labor resources. For compliance with CAIR regulations, TVA estimates a further investment of $3 billion to $3.5 billion.
Mercury emissions
Besides issuing the Clean Air Interstate Rule in early 2005, EPA also presented its first regulation requiring reductions in mercury emissions from coal-fired power plants, called the Clean Air Mercury Rule (CAMR).
TVA has been monitoring mercury levels in fish and sediment in TVA reservoirs for the past 30 years. Despite increased power production, which entails burning more coal, the data show that mercury is declining in sediments and remaining stable or declining in fish across the Valley. Where mercury levels from past industrial releases were high, they are now lower, and where they have historically been low, they remain low. More facts on mercury emissions and TVA:
• During 2004, an estimated 1.5 metric tons (3,370 pounds) of mercury were emitted to the environment by TVA plants. Mercury emissions from all U. S. coal-fired power plants nationwide represent 8 percent of total man-made emissions.
• Reductions in mercury emissions are provided by the technologies that TVA has installed to control NOX, SO2, and particulates. This co-benefit should reduce TVA’s mercury emissions by an additional 35 percent by 2010.
• Research at several TVA fossil plants indicates that units with both NOX and SO2 controls have the potential to lower mercury emissions by 85 percent or more depending on boiler configuration and coal types. TVA believes that mercury removal systems and measurement techniques will have to be improved before reductions beyond 85 percent are achieved.
• In one research project conducted during the spring and summer of 2004, TVA analyzed the presence of different types of mercury and trace gases at the Look Rock monitoring site in the Great Smoky Mountains National Park in east Tennessee. The research will provide a better understanding of mercury speciation chemistry and its relationship to wet and dry deposition of mercury in the region. This is important in developing workable methods of controlling mercury levels in the environment. However, much remains to be learned about the conversion of mercury from one form to another and the effect this has on mercury deposition into soil and water.
Read more about mercury research at TVA and EPA’s Clean Air Mercury Rule.
Clean air standards
EPA issued stricter National Ambient Air Quality Standards in 1997 for ozone and fine particles, and in 2005 it reclassified several counties in the Knoxville and Chattanooga area to “nonattainment” status for fine particles, meaning they failed to meet the new, more stringent standards. Previously the Valley had no nonattainment areas.
In calendar year 2005, TVA’s annual SO2 emissions, NOX emissions, and summer ozone season NOx emissions were the lowest at any time since all 59 coal units began operation. These low emissions are even more impressive considering that fossil generation in 2005 was 3.5 percent greater than in 2004 and was the third-highest calendar-year generation on record. But it’s clear that reducing power plant emissions alone won’t solve the new nonattainment problems. In 2005, TVA’s summertime NOX emissions in Tennessee were estimated to be only 11 to 12 percent of the total summertime NOx emissions in the state. TVA will further reduce its emissions, and reductions from other source sectors are expected and will need to occur to meet the ambient air quality standards.
Continued improvements in regional air quality will occur only when emissions from other common sources, including passenger vehicles and diesel trucks and buses, are decreased. EPA has adopted additional federal requirements to lower emissions from these sources, and the effects of these controls should become noticeable in time. TVA participates in numerous local partnerships to improve regional air quality, such as the Regional Clean Air Coalition, which supports efforts to reduce emissions and bring counties into attainment. Read about various local efforts at the Clean Air Council site.
TVA also supports a regional air quality monitoring and forecasting program for ozone and fine particles to help communities predict when air quality will or will not meet EPA criteria for public health. Overall, air quality is acceptable more than 95 percent of the time. Read about the Southeastern States Air Quality Toolkit, a resource to help local officials deal with air quality issues.
New Source Review lawsuits
TVA and other utilities continue to be involved in lawsuits alleging that maintenance projects at power plants in the past 25 years have required a New Source Review (NSR) permit under the Clean Air Act. One lawsuit was dismissed in TVA’s favor, and the dismissal has been appealed to the Sixth Circuit Court of Appeals. The other lawsuit, which involved TVA’s Colbert Fossil Plant Unit 5 in north Alabama, was also dismissed in TVA’s favor and has been appealed to the Eleventh Circuit Court. EPA is involved in lawsuits against other utilities in the East, but has also adopted or proposed changes to its NSR rules that would help clarify requirements. The proposed changes generally confirm that routine projects needed for the safe and reliable operation of generating units do not require NSR permits. In addition, TVA is involved in ongoing litigation alleging that Colbert Fossil Plant is in violation of the applicable opacity limit.
Effects of cooling water intakes on fish
TVA’s coal-fired and nuclear plants withdraw water from the river system to cool power plant components, and then in most cases return virtually all of the water to the river. Because cooling water intake structures can cause harm to fish, EPA has issued new regulations requiring power-producing facilities to minimize the adverse impact from these structures. Existing facilities must meet certain requirements for reducing the number of organisms affected by the plant's cooling systems or compensate for such occurrences by restoring habitat or pursuing other options, such as hatcheries, that produce fish or shellfish. TVA is conducting assessments at all of its generating plants and developing compliance strategies for each facility to meet the new rules.
Reportable environmental events
TVA continually strives to meet and surpass environmental standards. As with any organization of TVA’s size and complexity, however, events occasionally occur that trigger a notification to or enforcement action by a regulatory agency. The events occurring in 2004 and 2005 that had the greatest impact on the environment are described below.
1. At Paradise Fossil Plant, the failure of a seal oil system vacuum pump caused the release of about 950 liters (250 gallons) of turbine oil to the roof of the powerhouse, which drains into the plant’s discharge embayment. Absorbent pads soaked up much of the oil on the roof, but 190 to 380 liters (50 to 100 gallons) reached the discharge embayment, which connects to the Green River. Most of this amount was contained in the embayment behind the plant’s skimmer boom although enough material escaped to create a sheen on the river. Quick and effective action by the plant’s spill team and TVA’s Environmental Response Team limited the effects of the spill. Absorbent booms and pads were placed in the embayment and deflector booms were deployed on the river while the cleanup was in progress. To prevent a recurrence, TVA instituted a process for testing the system’s liquid level indicator and float-operated valve and has made modifications to the pump’s operation switch.
Reportable environmental events
|
Click chart for data. |
2. Actions that produce beneficial environmental effects can carry unintended consequences. That was the case at Widows Creek Fossil Plant when selective catalytic reduction (SCR) equipment was installed to control nitrogen oxide emissions and the plant’s scrubber was upgraded to further reduce SO2 emissions. In 2004, the new SCR on Unit 8 and improvements to the scrubber combined to increase the opacity of emissions from the stack, causing TVA to be above the limit set by opacity regulations. TVA used a hydrated lime injection technology to address the situation. Although the technology demonstrated the ability to reduce opacity, there were problems with the system’s reliability. An improved system is scheduled to be installed by July 2006.
3. After constructing the new Livingston-Jamestown transmission line, TVA carried out the final restoration work on the right-of-way. An inspection by the Tennessee Department of Environment and Conservation showed that control measures were not effective enough to keep sediment in one section of the right-of-way from migrating into a nearby stream and that a stream crossing had been temporarily modified without the appropriate permit. TVA revised the reclamation plans to address the problems, planting grasses and installing erosion control blankets and straw bales to better control sediment in water flowing across the area. The stream crossing was returned to its original condition. To help prevent similar incidents and to meet expanded state requirements for storm-water discharges resulting from construction activities, TVA hired three field technicians to inspect transmission line projects and ensure that erosion and sediment controls are properly installed and maintained.
4. A ruptured oil flow indicator on a 500-kilovolt transformer at a substation in middle Tennessee caused 14,385 liters (3,800 gallons) of mineral oil to spill into a containment pond. When heavy rains occurred the following morning, a large amount of rainwater entered the pond, allowing up to 38 liters (10 gallons) of oil to be discharged into the Harpeth River. Absorbent booms were placed downstream of the discharge water to remove the oil, and a mobile oil-water separator was brought in to contain the oily discharges from the pond. TVA is constructing a new pond for the transformers along with a containment facility in the existing breaker yard that will allow for additional oil retention capacity and increased separation of oil and water before a normal discharge of rainwater.
Toxics Release Inventory
The Environmental Protection Agency requires industries and utilities to report the release of 650 chemicals defined as potentially hazardous to human health. This collection of data is called the Toxics Release Inventory (TRI). TVA files annual TRI reports on 26 substances emitted by its fossil plants in quantities large enough to require reporting. TVA reported approximately 31,487 metric tons (69.42 million pounds) of chemical emissions to the air, water, and land for calendar year 2004, an increase of 19 percent over 2003.
Toxics Release Inventory
|
Calendar year 2004. |
The increase was due to several factors:
• A 4 percent increase in fossil power generation coupled with a greater use of eastern coal, which generally has higher levels of TRI-reportable substances.
• An increase in the use of selective catalytic reduction technology to reduce emissions of NOX, which produced an unexpected increase in emissions of sulfur trioxide (SO3), reported as sulfuric acid on the TRI. The good news is that the SCRs have significantly lowered NOX emissions. TVA has installed devices to reduce SO3 emissions on two SCR-controlled units and will install additional devices where SO3-related opacity problems have been experienced or are expected. Read more about the Toxics Release Inventory.
Biodiesel fuel testing
McMinnville Electric System (MES), a distributor of TVA power, is testing the use of biodiesel fuel for generating power. Biodiesel can be made from renewable sources such as soybeans, animal fats, or waste frying oil. TVA, Caterpillar Inc., and EmeraChem are partners with MES in the multiphase project, which first tested a blend of petroleum-based and biodiesel oils and will subsequently test 100 percent biodiesel. NOx emissions were brought to acceptable levels in phase-one tests, but the emission control equipment is being redesigned for phase two to improve its reliability.
Low-level radioactive and hazardous waste
Low-level radioactive Waste generated
|
Click chart for data. View 2006 revisions of target figures. |
In fiscal year 2004, TVA generated about 867 cubic meters of low-level radioactive waste at its three nuclear plants, about 2 percent less than its target of 884 cubic meters. However, in 2005, it generated 34 cubic meters more than its target (920 cubic meters), an increase of nearly 4 percent. The increase was the result of a longer-than-anticipated refueling outage at Watts Bar Nuclear Plant, including work to reduce radioactive contamination in specific work areas, an expanded work scope, and preparation for future outages that will involve major component change-outs.
HAzardous waste generated
|
| Click chart for data. See text at left for an explanation of the 2004 and 2005 figures. |
Percentage of audit findings Compared with 1995 baseline
|
| Click chart for data. The 2004 figure reflects an increase in waste storage and documentation issues. These issues were identified and corrected. |
In calendar year 2004, the total disposal of hazardous waste was 85 percent (425,938 kilograms) below 2003 levels. The decrease was primarily due to the completion of remediation work at several sites in the previous year. Such work involves the disposal of large amounts of hazardous waste. Comparing the waste disposal associated with normal work processes, the amount of hazardous waste disposed of in 2004 was 75,116 kilograms, compared with 101,892 kilograms in 2003, a 26 percent decrease.
In 2005, TVA disposed of 108,976 kilograms of hazardous waste, all from normal work processes, a 45 percent increase over 2004. This was primarily attributable to two large projects. In one, paint-removal material was improperly used at Kentucky Hydro Plant. In the other, nonhazardous waste was pumped into suspected contaminated tanks at Widows Creek Fossil Plant, requiring reclassification of the waste as hazardous.
Audit findings
Internal audits at TVA are performed by a central staff of environmental specialists. These audits monitor the effectiveness of the Environmental Management System at TVA facilities and help ensure compliance with local, state, and federal regulations. Since 1995, the percentage of audit findings has decreased by 80 percent.
