Loading...
HomeMy WebLinkAboutTVA PEIS SummarySummary of Tennessee Valley Authority's Draft Programmatic Ash Impoundment Closure Environmental Impact Statement In late December 2015, Tennessee Valley Authority (TVA) issued its Draft Ash Impoundment Closure Environmental Impact Statement (DEIS) to address the closure of CCR impoundments at its coal-fired power plants. The document is required by the National Environmental Policy Act, which requires federal agencies to prepare an Environmental Impact Statement (EIS) when proposing a major federal action significantly affecting the quality of the human environment.' TVA—a federally owned corporation—determined that the closure of its surface impoundments pursuant to the federal CCR rule triggered NEPA and the need for an EIS. The DEIS is organized in two parts: (1) a programmatic EIS (PEIS)2, which programmatically considers the environmental effects of closure -in-place (CI P)3 and closure -by -removal (CBR); and (2) an integrated analysis of ash impoundment closures at the six coal-fired generating stations within TVA's system. TVA's public and agency involvement for the DEIS includes a public notice and a 45 -day public review. During the public comment period on the DEIS, TVA expects to conduct 10 public meetings at fossil plants across the Tennessee Valley. Once the public and other agencies have reviewed the document, TVA will make any necessary revisions and issue a final EIS. This document summarizes only the PEIS and does not address TVA's CCR unit -specific analyses. The draft PEIS references the Electric Power Research Institute's (EPRI) model results showing that both CIP and CBR would have positive effects on groundwater and surface water. The model concludes that CBR would improve surface water and groundwater quality more than CIP, especially if the bottom of a CCR impoundment is in an aquifer. In contrast, EPRI concluded that CBR has significantly greater risks to public and worker safety, air quality impacts, and greenhouse gas (GHG) emissions than does CIP. Relying on the EPRI modeling results, TVA concludes that "in most situations, [CIP] likely will be more environmentally beneficial than [CBR], especially when the amount of borrow and CCR material that must be moved to and from a site is substantial.... The conclusions from EPRI's model helps [sic] to confirm EPA's assertion that either [CIP] or [CBR] can be equally protective if conducted properly...." The following chart summarizes important environmental impacts analyzed in the draft PEIS: 1 An EIS is a comprehensive public document that analyzes and discloses the environmental impacts of a federal action that will have a significant effect on the human environment. 2 Federal agencies rely on programmatic or broad -scale analyses to focus the scope of alternatives, environmental effects analysis, and mitigation in subsequent tiered levels of documentation (e.g., in site-specific analyses). For example, conclusions reached in the TVA PEIS are generally applicable to any CCR ash impoundment in the TVA system. Site-specific analysis for closure activities at individual ash impoundments will tier off (i.e., rely on) the programmatic analysis, re-evaluate the reasonableness of alternatives under consideration, and result in the identification of a preferred closure alternative at each site. 3 The CIP analysis includes CCR surface impoundments located both above and in aquifers. Issue Area CIP CBR Air Quality Temporary minor impacts from fugitive • Notably greater emissions than under the dust and emissions from equipment and CIP alternative vehicles during construction and transport • For sites with large volumes of CCR, of borrow material magnitude of impact would be greater due to increased operation of on-site equipment and increased duration and frequency of off-site trucking Climate Change and GHG Construction and trucking operations of For sites with large volumes of CCR, borrow material contributes to GHG magnitude of impact would be greater due emissions to increased operation of on-site equipment and increased duration and frequency of off- site trucking Groundwater • CIP activities will reduce risk to • Relying on EPRI's model, TVA explains in groundwater and improve water the draft PEIS that CBR has an quality—even in cases where the "incrementally more positive impact" elevation of the uppermost aquifer is relative to CIP (ranging from a 1.4 to 21.7- unknown, CIP provides the following fold increase in positive impact); however, benefits: for units containing larger volumes of CCR, o elimination of process water reduces "the extended duration of removal (up to the hydraulic head, therefore 70 years) would effectively diminish reducing the pressure of water benefits to groundwater quality forcing ash contaminants into improvement relative to [CIP]" groundwater; • Depending on the volume of CCR to be o installing a cover system improves removed, the impacts of CBR on groundwater quality by virtually groundwater are beneficial and could be eliminating rainfall infiltration considerable, as it eliminates subsurface through the impoundment and discharges and eliminates contaminants reducing downward migration of from the former CCR impoundment upon contaminants into groundwater; completion of the project; however, "until o NPDES outfall water quality improves the project is completed, which could take as contact with ash would cease up to 70 years, the benefit to following installation of a cover groundwater quality is expected to be less system, and the receiving river water than the [CIP] alternative because water quality would also improve; and infiltration through the CCR would o natural groundwater quality would essentially be stopped much earlier when eventually be reestablished the final cover system is in place" • CIP with a geomembrane "is considered to be one of the best options for improving groundwater quality beneath or downgradient of an ash impoundment or landfill" • "Considering the beneficial effects of removal of the hydraulic head from ash impoundments, the associated reduction in potential subsurface discharges from ash impoundments and the commitment to supplemental mitigative measures such as groundwater monitoring, as appropriate, the impacts of this alternative on groundwater would be beneficial and considerable...." Surface Water Because surface water flow and potential . Any pathways for transport of seepage to surface waters would be contaminants as a result of berm greatly reduced, potential direct and underseepage or groundwater discharge indirect adverse impacts to surface waters to adjacent surface waters would be Issue Area CIP CBR would be negligible and effect on surface eliminated over time water quality should be beneficial • Compared to CIP, any ongoing surface water impacts would be reduced more slowly because precipitation events would continue to influence flows from the CCR facility until the end of the closure process Transportation Temporary minor impacts from transport • Impact magnitude dependent upon CCR of borrow material volume and removal duration—for sites with large volumes of CCR, magnitude of impact would be greater due to increased duration and frequency of off-site trucking resulting in additional impacts to local traffic and increased need for roadway maintenance • Impacts on level of service of roadway network notably greater for sites having large CCR volumes and short removal durations, resulting in increased risk of injuries and deaths Public Health and Safety Temporary potential for impacts during • Potential for impacts during construction construction activities and transportation activities and transportation of borrow of borrow material material and CCR—increased risk associated with deep excavation of CCR impoundments • Notably greater risk to worker safety and traffic -related safety associated with sites having high CCR volumes Cumulative Effects' • Overall beneficial cumulative impact to • Overall beneficial cumulative impact to groundwater quality from closure of groundwater quality from removal of CCR CCR impoundments from impoundments • May result in air emissions and noise • Adverse cumulative impact to traffic that may potentially be adverse, but operations associated activities generally would • Cumulative impacts to air quality, GHG have a minor, short-term impact and contribution, noise, land use, natural localized effects that would not resources, socioeconomics, environmental contribute to cumulative impacts justice communities, and public health and safety would generally be expected to be greater than under the CIP alternative due to greater trucking and secondary effects on regional landfill capacity • Expected to result in more particulate matter emissions (PM10 and PMZ,$) due to the larger number of emission sources and the closer proximity of some emission sources, such as roadways, to residential communities 4 Cumulative effects are defined under NEPA regulations as the incremental environmental impact or effect of the action under analysis, plus impacts of past, present, and reasonably foreseeable future actions, regardless of what agency or person undertakes such other actions.