Environmental Stewardship at Gallatin
TVA takes environmental stewardship seriously; it is an important part of our mission of service. At Gallatin—as with every other fossil plant—that means assuring air and water quality are maintained at high levels.
TVA has taken a number of steps to improve air quality at Gallatin Fossil Plant and is moving forward to complete a $1 billion investment in air quality measures:
- The plant has historically used low-sulfur blend coal, which limits emissions of sulfur dioxide. In the future, when all environmental controls are in place, TVA will have the ability to burn a wider range of coal and still meet permit requirements.
- The plant is equipped with pulsejet fabric filter bag houses.
- Low-NOx burners on site limit the production of nitrogen oxides.
- In support of environmental agreements and to comply with regulations, TVA committed to add scrubbers and selective catalytic reduction (SCR) units on all four units at Gallatin by Dec. 31, 2017. All four scrubber units went into full operation in February of 2016.
- The new air quality measures at Gallatin Fossil Plant will significantly reduce emissions of sulfur dioxide and nitrogen oxides.
These actions will meet or exceed current U.S. Environmental Protection Agency (EPA) requirements. Read more about air quality efforts at Gallatin—and view all the supporting data—on our Gallatin Fossil Plant Emissions page.
TVA periodically collects and analyzes biological data upstream and downstream of its power plants, including Gallatin, to assess the health and structure of the aquatic communities that our operations could possibly impact. These data include monitoring of the fish and benthic macroinvertebrate (aquatic insect) communities and wildlife visual encounter surveys along the shoreline.
Fish community data are analyzed using the Reservoir Fish Assemblage Index, a series of 12 ecological health-assessment measures. Benthic samples are analyzed using the Reservoir Benthic Index, a similar series of seven health-assessment measures. For each analysis, the individual measures are scored and summed, and these totals provide comparative determinations of the ecological health of the respective fish and aquatic insect communities.
Since 2001, the fish communities in the areas upstream and downstream and within the potential influence zone of Gallatin operations have rated "good or "fair." The health of the benthic community at downstream sites was demonstrated to be similar or more favorable than upstream sites for each sample year. These results indicate that Gallatin operations are not having an adverse impact on the aquatic community in the Cumberland River near the plant.
TVA operates its Gallatin facility in compliance with water quality standards and permits issued by the State of Tennessee. Water quality samples show that this stretch of Old Hickory Reservoir meets all requirements for domestic and industrial purposes; propagation and maintenance of fish and other aquatic life; recreation in and on the water, including the safe consumption of fish and shellfish; livestock watering and irrigation; navigation; generation of power; propagation and maintenance of wildlife; and the enjoyment of the scenic and aesthetic qualities of water.
Gallatin also holds permits that guide the handling of its wastewater and stormwater; read more about them here.
In 2009, TVA committed to convert all of its wet coal ash management facilities to dry ash management at a potential cost of $1.5 to $2 billion.
At Gallatin, TVA is constructing a new dry ash landfill (the photo above shows liner installation for the new landfill), and is working toward closure of the active wet pond ash management system to comply with U.S. EPA’s new Coal Combustion Residuals rule. Read more about Gallatin Coal Combustion Residuals.
In accordance with its discharge permit issued by the state, TVA regularly performs maintenance inspections. The ash pond dikes have been thoroughly evaluated, and there are no issues with the stability or integrity of the plant’s current ash ponds.
Some environmental advocacy groups have sampled sediment in the Cumberland River immediately adjacent to historical ash ponds that TVA ceased using in 1970. In the late 1960s and early 1970s, there was erosion of minor amounts of ash from one spillway associated with these ponds. In 1975, TVA closed the spillway, sealed it with concrete and vegetated the area to prevent further erosion. These historical ash ponds were formally closed with approval from Tennessee Department of Environment and Conservation (TDEC) in 1998. The presence of localized ash in the river near this spillway is related to this historical erosion and is not related to TVA's current operations at Gallatin. There is no evidence that the localized presence of this decades-old ash has resulted in in impacts to public health or to the environment.
TVA has undertaken studies of groundwater in the area surrounding Gallatin Fossil Plant. These studies conclude that groundwater impacts are limited, and are predicted to remain limited in the future.
Two environmental advocacy groups have made public the results of TDEC’s sampling of two private wells near the Gallatin plant that found levels of hexavalent chromium slightly above a screening level for tap water that U.S. EPA uses in some regulatory programs; however, this screening level is not a federal drinking water standard. This screening level is based on a 2010 draft toxicity value that has not been finalized by U.S. EPA.
Though the results from the two wells were very low, TVA supports TDEC’s decision to retest those two wells—as well as several other wells in the region—so that a background level for naturally occurring hexavalent chromium in the area can be established.
More on Hexavalent Chromium
The U.S. EPA has yet to set federal drinking water standard for hexavalent chromium. Hexavalent chromium is a form of the element chromium and can occur naturally in soil, and therefore groundwater, depending on the type of rock formation.
It is only recently that state and federal programs have begun to test for low levels of hexavalent chromium in groundwater, surface water and drinking water; thus, our understanding of naturally occurring background levels is still developing. Data available from U.S. EPA indicate that hexavalent chromium is present in low levels of drinking water supplies across the country, including Tennessee. U.S. EPA reports that the average concentration of hexavalent chromium in drinking water in Tennessee is 0.00013 mg/L. The range of concentrations of hexavalent chromium in drinking water in Tennessee is 0.000015 to 0.0015 mg/L.
Hexavalent chromium is also generated by many different industries. Industrial sources include chromated pigments in dyes, paints, inks and plastics; chromates added as anti-corrosive agents to paints, primers and other surface coatings; chrome plating; chrome particles released during the smelting of ferro-chromium ore; the manufacture of stainless steel; and components of wood production.
TVA will be working with TDEC to identify potential sources of hexavalent chromium in the groundwater. Read more about TVA's environmental programs here.