Full opinion text
FINDINGS OF FACT & CONCLUSIONS OF LAW WAVERLY D. CRENSHAW, JR., CHIEF UNITED STATES DISTRICT JUDGE The Tennessee Clean Water Network and Tennessee Scenic Rivers Association (“Plaintiffs”) filed a Complaint against the Tennessee Valley Authority (“TVA”) alleging numerous violations of the Clean Water Act (“CWA”) related to TVA’s operation of a coal-fired power plant about five miles south of the city of Gallatin, Tennes-sée (“Gallatin Plant”). (Doc. No. 1.) On September 9, 2016, the Court dismissed a portion of Plaintiffs’ claims on the merits and a portion of the claims on the ground that the Court was barred from considering the allegations at issue in light of an ongoing State of Tennessee enforcement proceeding. (Doc. No. 139.) On January 30 through February 2, 2017, the Court held a bench trial on the remaining claims. For the reasons discussed herein, the Court will direct the Clerk to enter judgment for the Plaintiffs on Claims A, C, D, E.b, and E.e. It will direct the Clerk to enter judgment for TVA on Claims E.c and E.d, as well as Claims' B and E.a, which were dismissed by earlier Order of the Court. (Doc. No. 140.) TVA shall be ordered to excavate the Ash Pond Complex and Non-Registered Site and move the coal ash waste currently therein to a lined impoundment. In light of the substantial costs TVA is likely to incur in remediating its ash pond disposal areas, the Court declines to . assess penalties on top of its injunctive relief. I.CLAIMS 1. The following claims are before the Court: • Claim A alleges generally that TVA unlawfully discharged pollutants into the waters of the United States from a point source or point sources through hydrologic flow from its ash ponds to the Cumberland River. • Claim C alleges specifically that TVA is responsible for unpermitted point source discharges from the abandoned ash pond area known as the “Non-Registered Site.” • Claim D alleges specifically that TVA is responsible for unauthorized point source discharges from its currently active ash ■ pond complex, known as the “Ash Pond Complex.” • Claim E,b alleges that TVA violated Part I.A(cj of its NPDES permit. • Claim E.c alleges that TVA violated Part II.A(4.a) of its NPDES permit. • Claim E.d alleges that TVA violated Part II.C(2) of its NPDES permit. • • • Claim E.e alleges' that TVA violated Part II.C(3.b) of its NPDES permit. 2. In light of the Court’s September 9, 2016 ruling and the ongoing State proceedings, the above claims are limited to two types of alleged discharges from the Galla-tin Plant: discharges from the Non-Registered Site into the Cumberland River; and discharges from the Ash Pond Complex via hydrologic flows that are not seeps alone. By the terms of the Court’s Order, this limitation applies not only to claims A, C, and D—which explicitly allege unauthorized discharges—but also to claims E.b through E.e, insofar as those claims are premised on. allegations related to leaks. (Id.) II. NATURE OF FINDINGS AND CONCLUSIONS 3. After reviewing the parties’ proposed findings and conclusions, their arguments, the record, the exhibits received in evidence, and the testimony of the witnesses and consideration of their interests and demeanor, the Court enters the following Findings of Fact and Conclusions of Law in accordance with Rule 52(a) of. the Federal Rules of Civil Procedure. Except where the Court discusses differing testimony on a specific issue, any contrary testimony on that matter has been considered and rejected in .favor of the specific fact found. Finally, to the extent that a finding of fact constitutes a conclusion of law, the Court so concludes; to the extent that a conclusion of law constitutes a finding of fact, the Court so finds. III. FINDINGS OF FACT 4. Trial in this case involved the presentation of the often conflicting testimony of numerous experts on a number of closely related topics. The Court’s Findings of Fact, below, are a reflection of the information presented as well as the Court’s contemporaneous observation and assessment of the witnesses’ credibility. The omission of any particular detail from the below findings of fact should not be construed as the Court’s failure to consider that detail or inferences it would support, but rather merely an indication that, in the process of condensing a voluminous record, some details were omitted in the interest of conveying a manageably concise presentation of the relevant evidence and limiting the Findings of Fact to the details that the Court considered ultimately dispositive. A. Background 1. General Principles of Hydrology 5. This case is about water. Water comes in various forms and can be found in various places. 6. In its liquid form, water may pool or flow on top of the surface of the earth—for example, in the - Cumberland River. Because these bodies, of water can be found on the surface of the earth, they are categorized as “surface waters.” SURFACE WATER, Merriam-Webster Dictionary (online ed. 2017). 7. Water is also present below the surface of the earth, in what is- known as “groundwater.” GROUNDWATER, Merriam-Webster Dictionary (online ed. 2017). Liquid groundwater tends to flow-through the earth, from places of high elevation to places of lower elevation, eventually joining surface waters and flowing to the sea. (See Doc. No. 227-1 (Groves Wr. Test.) at ¶ 27.) 8. Not all earth, though, is created equal when it comes to the flow of groundwater. In some types of earth, such as gravel or loose soil, water may seep broadly through pores. In other types of earth, such as fractured rock, water may instead pass quickly but. narrowly through fissures. In yet other types of earth, such as tightly packed clay, water may not pass well at all, because there is no' space for the water to occupy. Portions of earth that readily transmit water are called “aquifers.” Portions of earth that do not readily transmit water are .called “aquitards.” Most groundwater environments include a mixture of the two, (See Doc, No. 230-1 (Perry Wr. Test.) at 4-5.) 9. Generally speaking, water that penetrates the earth will, due to the pull of gravity, flow downward until it penetrates what is known as the “water table.” (See Doc. No. 227-1 (Groves Wr. Test.) at ¶ 27.) The water table is the top of an area of earth totally saturated with groundwater. .Beneath the water table, at least as relevant to this case, is the continuous flow of groundwater through the earth toward surface waters. (Id.) The párticular elevation of the water table in any given area may fluctuate over time in response: to precipitation. ( See Doc. No. 230-1 (Perry Wr. Test.) at 14.) 10. Liquid or solid water falls to the earth in the form of precipitation—rain, sleet, or snow. If precipitation falls immediately upon a preexisting surface water, the precipitation will join that surface water. Water that falls upon the earth will either pool there—as surface water—or it will penetrate the earth and join the groundwater. (See Doc. No. 227-1 (Groves Wr. Test.) at ¶ 45.) 11. As water passes through the earth on its way to surface waters, it may pick up chemicals from the material it passes through and then carry those chemicals with it on its path to surface waters. (See Doc. No. 230-1 (Perry Wr. Test.) at 6.) If the water passes through an, area filled with pollutants—for example, a .large im-poundment of coal ash waste—it may pick up some of those pollutants and then convey them to nearby surface waters, 12. Water that penetrates a particular patch of earth directly from above—such as rain penetrating directly- into the earth it fell upon—is said to have penetrated that earth vertically. Water that penetrates a particular patch of earth via groundwater flow, on the other hand, is said to have penetrated it laterally. Generally speaking, if a particular patch of earth is wholly above the water table, it will be penetrated only vertically, when precipitation falls upon it or immediately near it. If the patch of earth extends past the water table and into a continuous groundwater flow, however, the patch will be penetrated both vertically, by immediate precipitation, and also laterally, by groundwater that could include water that first fell to earth a significant distance away. (See Doc. No. 227-2 (Quarles Wr. Test.) at ¶ 45.) , 13. For example, the below figure shows one zone of earth penetrated only vertically,- and one penetrated both vertically and laterally: 14. Because zone A terminates before breaching the water table, it is penetrated only vertically. Precipitation enters zone A at the surface of the earth, passes through it, then eventually joins the groundwater level below zone A’s lower boundary. 15. But because zone B extends past the water table, zone B is penetrated both vertically and laterally. Some water penetrates via precipitation at the surface, then flows down and joins the groundwater. Yet other water, already part of the groundwater flow, penetrates zone B from the side. 16. Although both hypothetical zones are penetrated by water, and the water from each eventually ends up in the same groundwater flow, a key difference exists in how one might shield the respective zones from future water flow. A simple surface cap would largely protect zone A by blocking precipitation. Pollutants from zone A then would be unlikely to join the groundwater flow in significant levels. A cap alone, however, would not keep out pollutants from zone B, because the cap would do nothing to impede the lateral flow of groundwater through those pollutants, even in the absence of penetration by immediate precipitation. If one truly wished to keep the pollutants from zone B out of the groundwater, one would need to either install a lining around its entire perimeter or ■ permanently excavate the pollutants. 17. In summary, these basic principles form the foundation of this case: (1) water, in the form of precipitation, penetrates the ground and becomes groundwater; (2) groundwater generally flows through the earth toward surface waters that ultimately connect to the sea; (3) as waters pass through the earth, they pick up chemicals, including potentially harmful pollutants, that they then convey to the surface waters; and (4) passage of water through a particularly toxic area can be prevented either by blocking the water or removing the toxins. 2. The Gallatin Plant 18. The Gallatin Plant is a four-unit coal-fired power plant located in Sumner County, Tennessee, about five miles south of the city of Gallatin on the Odom’s Bend Peninsula formed by the Old Hickory Lake portion of the Cumberland River between River Miles 242.5 and 246. (Doc. No. 226 (J. Stip.) at ¶ 1.) Old Hickory Lake is a reservoir created by the construction of the Old Hickory Lock and Dam. (Id. ■ at ¶ 5.) 19. Odom’s Bend Peninsula is situated over some karst geological features, with sinking streams, shallow bedrock, and sinkholes. (Id. at ¶ 17.) The Central Basin, in which the Gallatin Plant is located, is one of several major areas of karst development in Tennessee. (Doc. No. 227-1 (Groves Wr. Test.) at 1182.) 20. The Gallatin Plant commenced operation in 1956. (Doc. No. 226 (J. Stip.) at ¶ 3.) 21. From 1956 until 1970, the Gallatin Plant sluiced . coal combustion . residual (“CCR”) material to a 65-acre surface im-poundment on the western edge of the plant site known then as Ash Disposal Areas No. 1 and No. 2 but now typically referred to as the Non-Registered Site. The Non-Registered Site has been out of operation since 1970. (Id. at ¶ 7.) 22. TVA constructed the Non-Registered Site with unlined perimeter containment dikes made of earth and ash. (Id. at ¶ 11.) 23. In the mid-1990s, the Tennessee Department of Environment & Conservation (“TDEC”) asked TVA to formulate a closure plan for the Non-Registered Site, which TVA did. (Id at ¶ 8.) Construction work related to the closure was apparently completed in or around 1998. (Doc. No. 234 (Tr. Day 1) at 192.) 24. Since April 1970, TVA has been sluicing coal ash waste to the approximately 476-acre Ash Pond Complex, which is alsó unlined. (Doc. No. 226 (J. Stip.) at If 12.) The Ash Pond Complex is located just to the north and to the northeast of the Non-Registered Site along the bank of the Cumberland River. (Id. at ¶ 13.) 25. The Ash Pond Complex consists of the following ponds: Ash Pond A, Ash Pond E, Bottom Ash Pond, Middle Pond A, and a stilling pond complex consisting of Stilling Ponds B, C, and D. In 2015, TVA ceased sluicing ash to Ash Pond E and began, dewatering that pond. Stilling Pond D discharges effluent into the Cumberland River at a site known as Outfall 001. (Id. at ¶¶ 14-16.) 3. The Gallatin Plant’s Permit 26. On April 30, 1976, the U.S. Environmental Protection Agency (“EPA”) issued the first NPDES Permit to TVA for Galla-tin (Permit No. TN0005428). (Id. at ¶ 19.) The Ténnessee Department of Environment and Conservation (“TDEC”), which now administers Tennessee’s NPDES system on delegation from the federal government, re-issued the Gallatin Plant’s NPDES Permit No. TN0005428 on January 1,2006. (Id. at ¶ 21.)' 27. In May 2009, TVA submitted to TDEC an application for renewal of Galla-tin’s NPDES Permit No. TN0005428. TDEC reissued the Gallatin Plant’s NPDES Permit No., TN0005428 for a five year period beginning July 1, 2012, and ending May 31, 2017. (Id. at ¶¶ 22-23.) When the permit recently expired, it was administratively continued until the issuance of a new permit, currently under consideration. (Doc. No. 251 at 2 (citing Tenn. Comp. R. & Regs. 0400-40-05-.05(3)(b)-(4), 0400-40-05-.1K2)).) 28. The current permit expressly authorizes the discharge of coal ash waste from one location, Outfall 001. (J. Ex. 102 at 1.) 29. Part I.A(c) of the NPDES permit,known as the “Removed Substances” provision, provides: Additional monitoring requirements and conditions applicable to Outfalls 001 ... include: . c. Sludge or any other material removed by any treatment works must be disposed of in a manner, which prevents its entrance into or pollution of any surface or subsurface waters. Additionally, the disposal of such sludge or other material must be in compliance with the Tennessee Solid Waste Disposal Act, TCA § 68-31-101 et seq, and the Tennessee Hazardous Waste Management Act, TOA 68-46-101 et seq. (Id. at 11.) 30. Part II.A(4.a) requires TVA to “at all times properly operate and maintain all facilities and systems (and related appurtenances) for collection and treatment which are installed or used by the permittee to achieve compliance with the terms and conditions of the permit.” (Id. at 19.) 31. Part II.C.2 creates an obligation to inform regulators within twenty-four hours of certain events: In the case of any noncompliance which could cause a threat to public drinking supplies, or any other discharge which could constitute a threat to human health or the environment, the required notice of non-compliance shall be provided to the Division of Water Pollution Coiitrol in the appropriate regional Field Office within 24-hours from the time the permittee becomes aware of the circumstances. (Id. at 22.) 32. Part II.C.3.b forbids “Sanitary Sewer Overflows” at the Gallatin Plant, which the permit defines as “the discharge to land or water of wastes from any portion of the collection, transmission, or treatment system other than through permitted outfalls.” (Id.) 4. Plaintiffs’ Notice and State Court Proceedings 33. On November 10, 2014, Plaintiffs, through counsel, issuéd a 60-day Notice of Violation Letter to TVA, TDEC, and the EPA under the citizen suit provision of the Clean Water Act, 33 U.S.C § 1365 (“CWA” or “Act”), alleging multiple violations of the Act at the Gallatin Plant. See 33 U.S.C §§ 1251-1387. The Notice stated that Plaintiffs intended to file a complaint in federal court against TVA to enforce requirements of the CWA and the Permit. (Doc. No. 226 (J. Stip.) at ¶ 24.) 34. On January 7, 2015, the State of Tennessee (“State”) and TDEC filed an original enforcement action against TVA in Davidson County Chancery Court under applicable state statutes (“State Enforcement Action”). (Doc. No. 13-5 at PagelD 320-21.) The complaint in the State Enforcement Action specifically refers to ten seeps from the Ash Pond Complex, and the parties have identified those ten seeps to the Court. (Doc. No. 234 (Tr. Day 1) at 14.). 35. As part of the State Enforcement Action, which remains pending, TVA is in the process of completing and executing an Environmental Investigation Plan (“EIP”) that is intended to better investigate and understand the environmental features of the Gallatin Plant site. Plaintiffs, who are intervenors in the State Enforcement Action, as well as TDEC have been involved in the process of reviewing the EIP. 5. Proceedings in this Court 36. Plaintiffs filed their Complaint in this action on April 14, 2015.. (Doc. No. 1.) 37. The parties filed various dispositive motions, and on September 9, 2016, the Court issued an Order dismissing Plaintiffs’ Claims B and E.a. The Court also dismissed the remaining claims except as they applied to two sets of allegations: “discharges from the Non-Registered Site into the Cumberland River; and discharges from the Ash Pond Complex via hydro-logic flows that are not seeps alone.” (Doc. No. 140 at 1.) Finally, the Court struck Plaintiffs’ demand for a jury trial, on the ground that, because TVA is a creature of the federal’ government, the Seventh Amendment does not guarantee Plaintiffs a right to a jury trial. (Id.) 38. Accordingly, the claims that had not been dismissed were considered by the Court in a bench trial held from January 30 through February 2, 2017.. By agreement of the parties and pursuant to Local Rule 39.01(c)(6), direct testimony of expert witnesses was provided in written form, which was accepted into evidence. Key portions of the written testimony were read in Court, after which the expert witnesses were made subject to cross examination. B. Plaintiffs’ Evidence at Trial 1. Testimony of Dr. Chris Groves 39. Dr. Chris Groves holds' the position of University Distinguished Professor of Hydrogeology at Western Kentucky University (“WKU”). He has a B.S. degree in Geology and an M.S. degree in Geography from WKU, as well as a Ph.D. in Environmental Sciences (Geology) from the University of Virginia. He is currently serving as a member of the steering committee of the Karst Commission of the International Geographic Union and has amassed a lengthy resume of' professional service, honors, grants, and publications indicative of accomplishment and expertise in the field of hydrogeology. (Doc. No. 163-1 (Groves CV).) Groves is licensed as Kentucky Professional Geologist No. 2585. (Doc. No. 227-1 (Groves Wr. Test.) at ¶3.) 40. Groves described hydrogeology as the science of how underground water is distributed and how it moves through the soil as soil water, and through rocks beneath the surface as groundwater. (Id. at ¶ 28.) 41. Hydrogeology includes examination of issues related to water quality and how water’s chemical ■ composition is impacted by interactions with rocks, gases, biological processés, surface waters, and human sources of contamination. (Id.) 42. Groves testified that he has more than thirty years of professional experience in the study of landscape and aquifer systems, and that this case was the first matter in which he had been retained as an expert witness in a lawsuit or testified in court as an expert witness. .(Id. at ¶¶ 2-3.) . 43. The parties have stipulated and agreed that Groves is qualified as an expert by knowledge, skill, experience, training, or education pursuant to Federal Rule of Evidence 702. (Doc. No. 221.) 44. Groves stated his opinion that, based on his review of historic maps, borings, and TVA’s own internal reports, as well as his own knowledge and understanding of hydrogeological formations in the Central Basin and Odom’s Bend Peninsula, he considered the Gallatin Plant coal ash disposal sites “unsuitable for the containment of coal ash.” (Id. at ¶ 7.) 45. Specifically, he opined that the Ash Pond Complex does not and cannot effectively contain coal ash waste, and in particular was constructed on top of highly porous limestone with numerous existing sinkholes and .an.associated underground karst flow system. He stated that these features permit the waste to migrate into groundwater and to the adjacent and hy-drologically connected Cumberland River. (Id. at ¶ 8.) 46. Groves testified that, in his opinion, both the Non-Registered Site and. the Ash Pond Complex were constructed at least partially below the water table and are thus in contact with the groundwater. (Id. at ¶ 9.) 47. Groves testified that, in general, water flows from high areas to low areas of the water table, and that, in this case, the groundwater flows from the peninsula, including from the Ash Pond Complex, to the Cumberland River. (Id. at ¶ 27.) Groves presented a 2012 water table map showing the water table reducing in level from the interior of Odom’s Bend Peninsula toward the river, tending to suggest that, generally speaking, water flows radially from the interior of the peninsula to the river, passing through both the Ash Pond Complex and Non-Registered Site. (Id. at ¶¶ 106-07.) Groves noted that TVA’s historical documents acknowledged this general groundwater flow pattern numerous times. (Id. at ¶ 110.) 48. He described the Central Basin as a relatively simple geologic setting consisting of nearly horizontal sedimentary rock layers, with each rock layer being distinguishable by various properties, including porosity and permeability. (Id. at ¶ 33.) The nearly horizontal aquifers that underlie the Central Basin include layers of Carters and Ridley Limestones. Water flows relatively easily through these rocks because, compared to the adjacent layers, they are purer limestones, which dissolve easily and thus contain fractures that have been enlarged by dissolution as groundwater moves through. (Id. at ¶ 35.) ■ 49. Groves discussed in particular an April 2008 document prepared by TVA titled “Final Environmental Impact Statement Rutherford-Williamson-Davidson Power Supply Improvement Project Rutherford Williamson and Maury Counties Tennessee, TVA Project Number 2005-107” (“2008 FEIS”). (Id. at ¶¶ 36-37 (discussing J. Ex. 49)). 50. Groves approvingly cited the 2008 FEIS’s statement that, in the Central Basin aquifer system, “most of the groundwater resides in and flows through fractures, bedding planes, small solution openings, and large open conduits.” (Id. at 1137 (quoting J. Ex. 49 at 67)). 51. The 2008 FEIS further states that “[ljimestone is susceptible to erosion and dissolution, which produces fissures, sinkholes, underground streams, and caverns forming vast karst areas.” (J. Ex. 49 at 67.) It states that the “project area” is located in karst terrain, and that [kjarst landforms result from mildly acidic rainwater dissolving bedrock such as limestone or dolostone. Over time, these fractures enlarge as the bedrock continues to dissolve. Openings in the rock increase in size, and an underground drainage system begins to develop, allowing more water to pass through and accelerating the formation of underground karst features. (⅛) 52. Groves testified that in karst landscapes, tributary networks combine with one another, leading to larger and larger flows. (Doc. No. 227-1 (Groves Wr. Test.) at ¶ 39.) Consistently with Groves’ assessment, the 2008 FEIS states that Groundwater flows from the recharge areas through fractures and conduits and eventually discharges to springs and gaining streams. Large conduits or interconnected conduit systems may consolidate groundwater flow similar to the way surface water flows from small tributaries to larger streams. These interconnected, open conduits (the groundwater conduit system) can transmit water rapidly and can act as important local and regional drains of the groundwater system. (Id. (quoting J. Ex. 49 at 67).) “Recharge” refers to water that has infiltrated into the ground. (Id. at ¶ 38.) 53. The 2008 FEIS farther observes that “[groundwater in karst terrains is readily susceptible to contamination, as the water can travel long distances through conduits with no chance for the natural filtering processes of soil or bacterial action to diminish the contamination.... Karst features in the project area include sinkholes, disappearing streams, . reappearing streams (springs), and caves.” (J. Ex. 49 at 68.) 54. Groves described the aquifer framework in karst landscapes as “colander-like” due to the abundance of passages through which water can move. (Doc. No. 227-1 (Groves Wr. Test.) at ¶41.) He testified that the' hydrogeological literature describes many examples of situations where karst limestone aquifers of Tennessee’s Central Basin, and the rivers into which they drain, have been polluted by accidental spills and other releases of contaminants. (Id. at ¶ 43.) 55. Groves testified to his opinion, based on his review of literature and case materials, that at the Gallatin Fossil Plant, underground water primarily flows through openings that have been enlarged by the flow of water within the purer limestones. (Id. at ¶ 44.) In particular, the Carters Limestone that underlies the Ash Pond Complex transmits groundwater-comparatively easily and rapidly through fractures and other conduits that have been enlarged by dissolution of the limestone bedrock by groundwater flowing through it. (Id. at ¶ 46.) 56. Groves explained that the karst-en-abled drainage in the ash ponds themselves was obscured from view by coal ash waste, but that if the area had not been covered by. coal ash waste, one would expect to see rainfall landing on the, ground and quickly sinking underground into the highly porous bedrock. (Id. at ¶ 45.) 57. Groves discussed TVA’s historical documentation of the geology of the area before TVA built the ash pond disposal sites. The documentation showed numerous limestone sinkholes in the area that is now the Ash Pond Complex. It also showed numerous lineaments—naturally occurring, linear features of the landscape that provide insight into the subsurface fracture patterns and magnitude. (Id. at ¶¶ 48-52.) Based on Groves’ review of TVA’s map, he concluded that the subsurface fractures in Odom’s Bend Peninsula are extensive and would allow water and any waste in the wáter to drain into the groundwater. (Id. at ¶53.) Groves stated that he had never seen any TVA documentation that these fractures were repaired, and that he believed any such repair to be nearly impossible in light of the fractures’ extensive nature. (Id.) - 58. Based on the foregoing, Groves stated that it was his professional opinion that fractures and related solutionally enlarged conduits under the coal ash disposal areas transport coal ash waste to the groundwater. (Id.) 59. Groves also noted that his review of the Tennessee Cave Survey showed at least nine explorable caves in the area including Odom’s Bend Peninsula, and that it was his opinion that because there are so many caves in this area, there is a high probability that other caves were present on Odom’s Bend that have been covered by coal ash waste and slurry water.. (Id. at ¶ 55.) 60. Groves. next discussed logs of bor-ings performed by TVA and its contractors in the vicinity of the Ash Pond Complex. As Groves read the logs, the borings identified at least seventy “voids” or “apparent voids” in the earth, ranging from 4 to 18.6 feet in height, many of which were connected to the groundwater flow system. (Id. at ¶ 59.) 61. Groves also opined that, based on his review of historical documents, the Ash Pond Complex was located on top of a sinking stream referred to ■ as “Sinking Creek.” Sinking streams are streams that sink underground into the highly permeable limestone beneath and drain through the karst aquifer system to the nearest base level river, in this case the Cumberland River. Groves described sinking streams as among the most classic of karst features. (Id. at ¶¶ 60-65.) 62. Sinking streams disappear underground at “swallets”—holes into which the stream disappears into the subsurface. The water continues flowing underground to the relevant, river, here the Cumberland. Groves’ opinion, based on the historical documentation, was that the swallets of Sinking Creek are currently underneath the Ash Pond Complex. (Id. at ¶¶ 63-65.) 63. Groves opined that, because the former surface of the valley of Sinking Creek is, based on his reading, now the base of the Ash Pond Complex, he would assume that the coal ash waste water now moves directly into the subsurface under the Ash Pond Complex to the Cumberland River, just as water moved through the bottom of Sinking Creek to the Cumberland River before it held the Ash Pond Complex. (Id. at ¶ 101.) 64. Groves reviewed numerous TVA findings and reports regarding the groundwater and/or geology around the Gallatin IPlant, including reports from 1982, 1987, 1989, 1992, 1999, 2002, and 2009. (Id. at ¶ 68.) He testified that many of the reports reached conclusions supportive of or similar to his own. (Id. at ¶ 69.) For example, the “1982 Groundwater Report” stated, “In the vicinity of Gallatin Steam Plant, most of the surface streams flow a short distance across the ground, then disappear into sinkholes and drain into underground channels in the limestone bedrock.” (J. Ex. 44 at 35.) 65. The 1982. Groundwater Report also states. that “[w]ater-table elevations are probably within the ash disposal pond.” (J. Ex. 44 at 35.) 66. The 1987 Groundwater Report similarly acknowledges thht the “[w]ater table is believed to be within the waste pond.” (J. Ex. 45 at 27). • 67. Groves’ review showed that during the early years of the Ash Pond Complex’s operation, as TVA does not appear to dispute, the complex suffered significant leakage through hydrological connections to the Cumberland River. (Doc. No. 227-1 (Groves Wr. Test.) at ¶¶ 74-79.) By Groves’ estimate, between April 1970 and December 1978, approximately 27 billion gallons of coal ash wastewater flowed directly from the Ash Pond Complex into the karst aquifer and then into the Cumberland. (Id. at ¶ 79.) 68. Based on his review of TVA studies, Groves believed that this early leakage was occurring through some number of sinkholes—variously reported from between 59,101, and 111—but that TVA had ultimately been unable to identify the actual number of sinkholes that were leaking. (Id. at ¶ 86.) 69. In 1977, a TVA research engineer produced a report titled “Magnitude of Ash Disposal Pond Leakage Problem— Gallatin Steam Plant” (“1977 Leakage Memorandum”), which discussed TVA’s understanding, at the time, of the leakage from the pond. (J. Ex. 41.) The 1977 Leakage Memorandum explains: The actual number of sinkholes which are presently leaking to the subsurface cannot be determined without extensive field studies .... Based on examination of topography of the- pond which was taken in 1952 (before the impoundment of Old Hickory Lake), 1963 and 1977, several sink holes were wet weather ponds or were termination points for streams that flowed into the area now covered by the pond. Therefore it is likely that several sink holes in the present ash disposal pond leak to the subsurface. If the present leaks from the pond were plugged and the water level in the pond rose to the elevation of the outfall weir, one ■ or more of another 52 sink ’holes could begin to leak. In addition, sink holes which are not presently leaking could begin to leak because of increased hydrostatic pressure. From the previous discussion, it can be concluded that the network of solution cavities and crevices in the groundwater system under the pond is extensive. Therefore, identification of the sink holes which presently leak to this system would require extensive field studies. In addition, plugging the presently leaking sinkholes would give no, assurance that other sink holés would not begin to leak, as previously discussed. (Id. at TVGF-008091-92.) 70. Groves described steps taken to repair the Ash Pond Complex after its early leakage. As Groves described it, some sinkholes under the Ash Pond Complex were plugged, which caused the water level to rise to the outfall. The water rising, however, did not demonstrate that all leaks had been eliminated. The water level rising only meant that the inflow rate into the ponds exceeded the outflow rate. That outflow rate could still' have included outflow through karst drainage. (Doc. No. 227-1 (Groves Wr. Test.) at ¶ 89.) 71. TVA’s 1992 Groundwater Report echoes the conclusion that rising waters show only a reduction, not necessarily an elimination, of leakage: “Following the plugging of several sinkholes in the northwest end of the pond in 1978, the leakage rate was reduced and a point source discharge was established at the pond outfall.” (J. Ex. 47 at 5.) 72. Based on his review and the foregoing, Groves opined that most of the conduits below the Ash Pond Complex were never plugged or repaired and that, accordingly, coal ash waste is still within the groundwater and likely still flowing into the river. That drainage, however, cannot be directly seen because it is obscured by the coal ash waste itself. (Doc. No; 227-1 (Groves Wr. Test.) at ¶ 90.) 73. Groves’ expert opinion was that, given the hydrogeological conditions of Odom’s Bend, the evidence of leakage into the Cumberland River, and that groundwater on Odom’s Bend Peninsula is expected to flow into the Cumberland River, any suggestion that coal ash waste water is not currently going to the Cumberland River, or is going anywhere other than the Cumberland River,' is implausible. (Id. at ¶ 102.) 74. Groves performed an analysis based on historical groundwater flow reports and maps, as well as evidence from nearby ground wells, purporting to demonstrate that there is a major conduit and underground river parallel to, and north of, the axis of the Ash Pond Complex, likely terminating at a flow outlet into the Cumberland River. (Id. at ¶¶ 116-26.) 75. Groves also opined that dewatering and capping the ash disposal areas without a liner will not prevent contamination of groundwater or the Cumberland River by coal ash waste, because such’ steps would not eliminate ongoing drainage through karst features. (Id. at ¶ 132.) 76. On cross examination, Groves admitted that he had never personally been on the site of the Gallatin Plant. (Doc. No. 234 (Tr. Day 1) at 53.) 77. Groves further conceded that, in some portions of the Ash Pond Complex, there was a layer of clay between the ash and the karst underneath. (Id. at 65.) 78. TVA pointed out that a 2010 report created for TVA by Stantec Consulting Services Inc. (“2010 Stantec Report”) (J. Ex. 67) included the statement that “[t]he thickness of the native soils above the bedrock across the pond complex range from as little as about one foot or less to as much as twenty feet.” (Doc. No. 234 (Tr. Day 1) at 66-67.) Groves acknowledged the statement in the Report, but argued that it was inconsistent with the Report’s own data, which showed that there were some places in the Ash Pond Complex where waste was in direct contact with bare rock. (Id. at 67.) TVA also pointed out select borings that showed substantial clay cover at specific locations in the Ash Pond Complex. (Id. at 67-69.) 79. The 2010 Stantec Report also states that the Gallatin Plant “ha[d] not experienced any known ... karst-related problems within the ponds in recent years” other than the following: an area designated for the expansion of Pond E contained known sinkholes, which were mitigated during construction; a recent rain event had revealed a sinkhole to the north of Pond C; and in 1990, a sinkhole that had previously been isolated by a dike was repaired. (Id. at 70; J. Ex. 67 at 8.) 80. TVA’s cross examination also established that there are a number of techniques and mechanisms for identifying the relevant hydrogeology in karst systems that Groves, who relied primarily on historical documentation, did not rely on in this case. (Doc. No. 234 (Tr. Day 1) at 81-86.) On re-direct, Groves explained that he was confident in his conclusions despite not having used such methods. (Id. at 101.) 81. Finally, Groves admitted that the Non-Registered site was not located atop karst features, but rather alluvial deposits, defined as “unconsolidated sediment that has been deposited by a surface stream or river.” (Id. at 55-57.) 82. Based on its direct observation of Groves’ demeanor, candor, and responsiveness, the Court found Groves to be generally credible. The Court did, however, evaluate Groves’ opinions in the context of his having been retained by the Plaintiffs. His opinions, moreover, were rendered somewhat less persuasive because they were based primarily on his review of past literature and general understanding of karst terrains, rather than direct analysis of the coal ash disposal areas themselves. That deficiency, though relevant to the weight of his testimony, did not wholly negate its persuasive and explanatory value. 2. Testimony of Mark Quarles 83. Mark Quarles is a Tennessee-licensed professional geologist with a B.S. degree in Environmental Engineering Technology from WKU. He characterizes himself as a “[p]ublic interest environmental consultant.” Quarles testified that he has approximately thirty years of experience as an environmental consultant, including a substantial amount of experience consulting for industrial sector clients. (Doc. No. 227-2 (Quarles Wr. Test.) at ¶¶ 1, 3, 5.) 84. Quarles’ consulting company, Global Environmental, LLC, (“Global Environmental”) was retained by Plaintiffs to evaluate the conditions of the Gallatin Plant. (Id. at ¶ 1.) 85. Quarles testified that he has been trained in and is experienced in taking samples to determine the existence of and extent of contamination. (Id. at ¶ 3.) He claimed extensive experience evaluating groundwater movement in karst environments, particularly in Middle Tennessee, including work involving sinking creeks and sinkholes. (Id. at ¶ 5.) 86. Quarles also stated that he has many years of experience conducting hydrogeo-logical investigations related to siting and design of municipal and industrial waste landfills, developing closure plans for industrial landfills, designing and implementing groundwater monitoring programs for industrial landfills, completing investigations to define the nature and extent of industrial contamination in the environment, and completing coal combustion waste investigations. He has performed coal combustion-related investigations at over seventy sites located in twelve states. (Id. at ¶¶ 6-7.) 87. The parties have stipulated ■ and agreed that Quarles is qualified as an expert by knowledge, skill, experience, train-ingi or education pursuant to Federal Rule of Evidence 702. (Doc. No. 221.) • ■ 88. Quarles echoed Groves’ assessment that the Sinking Creek stream valley rendered the area of the Ash Pond Complex a poor choice for the disposal of coal ash waste, due to its karst features and the connectivity of the groundwater. (Doc. No. 227-2 (Quarles Wr. Test.) at ¶¶ 9-10.) • 89. Quarles gave his opinion that both the Ash Pond Complex and the Non-Registered Site contain coal ash waste that extends below the groundwater level. (Id. at ¶ 12) 90. Quarles testified that Global Environmental was able, through visual inspection and manual probing, to identify solid coal combustion wastes several feet thick in the Cumberland River along the shoreline of both the Ash Pond Complex and the Non-Registered Site. (Id. at ¶ 18.) 91. Quarles’ review of historical maps yielded conclusions similar to Groves’: that the Gallatin Plan was built on an area óf significant karst activity, including sinkholes and sinking streams on the Plant property. (Id. at ¶¶ 82-33.) 92. Quarles also echoed Groves’ conclusion that the Ash Pond Complex was constructed over a sinking stream known as Sinking Creek. (Id. at ¶ 34.) 93. Quarles also identified a large sinkhole complex northeast of the Plant (“Neighboring Sinkhole Complex”). (Id. at ¶33.) Quarles opined that, because the Neighboring Sinkhole Complex, does not have an obvious resurgence point where any flows reach the ground surface or discharge into a surface water stream, the Neighboring Sinkhole Complex may be connected by groundwater to the Ash Pond Complex. (Id. at ¶ 40.) 94. Quarles discussed the larger drainage basin from which natural precipitation runoff flows through the main discharge channel from the Ash Pond Complex and into the Cumberland River. Quarles cited a 2013 TVA report (J. Ex. 71) for the conclusion that the drainage basin is approximately 4,000 acres, with surface drainage flowing from at least three miles to the North of the Gallatin Plant. (Doc. No. 227-2 (Quarles Wr. Test.) at ¶ 41,) 95. For example, surface water overflow from the Neighboring ■ Sinkhole Complex flows across TVA property, flows into a catch basin, and discharges into the Ash Pond Complex. Quarles provided photo-, graphic evidence appearing to depict off-site drainage flowing into the Ash Pond Complex. (Id, at ¶ 43; J. Ex. 73 & 140.) 96. Global Environmental developed conceptual models for both the Non-Registered Site and the Ash Pond Complex, based on 1930 and 1952 topographic maps and the sites’ pre-development ground elevations. (Doc. No. 227-2 (Quarles Wr. Test.) at ¶ 44.) Those models were presented in the form of cross-sectional diagrams designed to demonstrate certain features of the sites and relevant hydrogeology. (J. Ex. 141 & 142.) The Court did not construe the models as presenting literal, to-scale representations of the ponds, but rather as conceptual illustrations intended to assist the Court in’its understanding of Quarles’ analysis. 97. Quarles testified that, although the conceptual models relied on some information from 1930 and 1952, he believed them to accurately reflect current conditions, in particular with regard to the elevation of the underlying bedrock and the level of the river. Quarles testified that he would not expect those values to have changed in the relevant intervening years. (Doc. No. 235 (Tr. Day 2) at 9-10.) 98. The conceptual model of the Ash Pond Complex depicts, among- other things, waste escaping through sinkholes in the bottom of the pond into a conduit flow through -the underlying limestone. The model also illustrates coal ash waste below the groundwater elevation as of May 23, 2012. (J. Ex. 141.) 99. The conceptual model of the Non-Registered Site depicts submerged coal ash .waste below the groundwater level, and groundwater passing through the Site to the Cumberland River. (J. Ex. 142.) ' 100. Quarles’ conceptual analysis concluded that the area’s elevated aquifer, the hydraulic connectivity of the underlying bedrock to the Cumberland River, and the original ground topography have resulted in solid wastes in both disposal areas that are saturated under natural groundwater and riyer water flow, conditions. (Doc. No. 227-2 (Quarles Wr. Test.) at ¶ 45.) Quarles testified that his review of TVA’s historical studies substantiates the conclusions of his conceptual models, in particular his conclusions that ash is buried within the groundwater at both the Ash Pond Complex and the Non-Registered Site; that the groundwater is hydrologically connected to the Cumberland River; and that TVA has discharged and will continue to discharge pollutants from the waste to the riyer. (Id. at ¶ 61.) 101. Quarles cited the 2010 Stantec Report (J. Ex. 67) and more recent studies performed for TVA by Arcadis U.S., Inc., (“2014 Arcadis Report”) (J. Ex. 59) as supporting his conclusion that both the Ash Pond Complex and Non-Registered Site contain coal combustion" wastes that are saturated with watér. (Doc. No. 227-2 (Quarles Wr. Test.) at ¶¶ 71-72.) The 2010 Stantec Report based its analysis on a geotechnical exploration plan involving borings at more than thirty, locations. (J. Ex. 67 at. 8.) The 2014 Arcadis Report assessed the Non-Registered Site through a combination of groundwater monitoring wells, soil data, and other hydrogeologic information. (J. Ex. 59 at TVGF_004702.) . 102. According to Quarles, that the Non-Registered Site still contains saturated ash forty-five years after waste placement ended demonstrates that groundwater continues to recharge the wastes from topographically and hydraulically upgradient areas that.flow into the wastes. (Doc. No. 227-2 (Quarles Wr. Test,) at ¶ 121.) 103. According to Quarles, Arcadis concluded that contaminated groundwater discharges into the Cumberland River along the Non-Registered Site shoreline. (Id. at ¶ 100.) 104. The 2014 Arcadis Report includes a figure titled “Site-Wide Potentiometric Contours” that depicts the “Inferred Flow Direction” of groundwater on Odom’s Bend Peninsula. (Id. at ¶ 74 (citing J. Ex. 59 at TVGF_004759 (Fig. 7)).) .The figure depicts water flowing from a high point in the center-east of the peninsula toward the river, including passage through both the Ash Pond Complex and the Non-Registered Site areas. The groundwater flows depicted include the flow of water through the Ash Pond Complex area toward a location near or upstream from the sediment sampling locations identified below as East Side 1 and East Side 2. (J. .Ex. 59 at TVGF_004759 (Fig. 7).) Groundwater is also depicted as flowing through the Non-Registered Site in the direction of points near or upstream from the sediment sampling locations identified below as NRS 1 through NRS 6. (Id.) 105. Quarles also summarized the 2014 Arcadis Report’s conclusions regarding the Non-Registered Site. Quarles interpreted the Report as concluding that, coal ash waste constituents, often in high concentrations, remain in the Non-Registered Site, migrating towards and beneath the main channel of the’ Cumberland River. (Doc. No. 227-2 (Quarles Wr. Test.) at ¶¶ 80-81.)’ 106. On cross examination, however, Quarles conceded that the 2014 Arcadis Report concluded that the uppermost groundwater at the Non-Registered Site occurred in alluvial deposits and residuum soil, not in ash. Quarles explained the conflict between his analysis and Arcadis’s as a result of Arcadis having relied on wells around the perimeter of the area, whereas his model relied on wells and borings through the ash.-(Doc. No. 234 (Tr. Day 1) at 197-98.) 107. Quarles also conceded that the 2010 Stantee Report had stated that the Plant “ha[d] not experienced any known additional karst-related problems in recent years.” (Id. at 200.) 108. Quarles identified, a- March 2015 PowerPoint presentation by TVA contractor AECOM stating that “[a] portion of the ash [in Ash Pond E] is below (up to 10 feet below) the elevation of the Cumberland River.” (Doc. No. 227-2 (Quarles Wr. Test.) at ¶ 73 (citing J. Ex. 113 at 7).) The presentation also acknowledges the possibility that the Pond could be hydrologically connected to the river, and specifically cites the possibility of karst activity, including sinkholes. According to the slide, if the Pond is hydrologically connected to the river, it would be effectively impossible to wholly dewater the Pond due to that connection. (J. Ex. 113 at 7.) 109. Quarles evaluated TVA’s groundwater monitoring program. Although he identified a number of what he considered deficiencies in the program, he nevertheless concluded that TVA’s monitoring had demonstrated/corroborated contamination of the groundwater with coal ash waste. (Doc. No. 227-2 (Quarles Wr. Test.) at ¶¶ 83-98.) 110. Quarles and Global Environmental also conducted a field investigation, with the cooperation of Barry Sulkin and others. (Id. at ¶ 46.) Quarles and others inspected the shoreline of the Cumberland River along the Gallatin Plant peninsula, looking for signs of coal and coal combustion waste, targeting portions of the shoreline that were (1) hydraulically downgradient of groundwater flow from ash disposal areas; (2) along bedrock joint trend lines that could be preferential groundwater flow pathways; (3) former valleys and hollows that are now fully or partially submerged by the impounded Cumberland River; and/or (4) areas of past impoundment dike failures. (Id.) 111. Global Environmental performed boat-based inspections of identified target sites, including sediment and water sampling, in October 2014 and August 2015. Quarles testified chiefly about the sediment sampling, leaving Barry Sulkin to discuss the water sampling. (Id. at ¶ 50.) 112. Quarles identified " fourteen sampling locations, which he characterized as follows: • East Side 1—We observed a diffuse flow spring located on the eastern peninsula at a public boat ramp along the shoreline of the Cumberland River. This site is hydraulically downgradient of the eastern portion of Ash Pond A and along the secondary bedrock joint pattern,, and is located in a pre-impoundment valley. The sample was collected from an opening in a submerged channel in fill material. • East Side 2—We observed a diffuse flow spring also located on the eastern peninsula at the shoreline of the Cumberland River. This site is down-gradient of the northeastern portion of Ash Pond A along the secondary bedrock joint pattern and is in the vicinity of former (apparently closed or no longer sampled) well GAF 13— a well with demonstrated coal combustion waste constituents and up to 2,100 mg/L sulfate. The sample was collected where the spring flows into the river. • Barton’s Creek Reference—This sample site is located off TVA property south of the Cumberland River along the shoreline of Barton’s Creek, an upstream tributary of the Cumberland River. The shoreline sediment sample was collected at the Barton’s Creek Boat Ramp, a public boat ramp on the tributary to Old Hickory Lake, located off of Coles Ferry Pike. • NRS 4—This shoreline sediment • sample was collected from the small southerly embayment adjacent to the NRS. It was collected outside of the submerged zone but below the high water mark of the river and within approximately 1 foot of the waterline of the Cumberland River. • NRS 3—This submerged sediment sample was collected approximately 50 feet from the shoreline (approximately 3-foot water depth) from the same southerly embayment adjacent to the NRS. It cqnsisted of an undetermined mixture of black sludge-like material and mud sediments that was at least 2 feet thick. • NRS 2—This shoreline sample was collected from the southerly embayment adjacent to the NRS, but from the area nearest well 27. It consisted of a coarse, reddish-brown to black, clayey sand. It was collected outside of the submerged zone but below the high water mark and within 1 foot of the waterline of the Cumberland River. • NRS 1—This submerged sample (approximately 3-foot water depth) was collected in the northerly embayment adjacent to the NRS, located approximately 10 feet from the shoreline. Consisted of an undetermined mixture of black sludge-like material and mud sediments that was at least 2 feet thick. • APC 1—This western shoreline sample was collected adjacent to a rip-rap repair of Ash Pond E. It was collected outside of the submerged zone but below the high water mark of the Cumberland River. • APC 4—This submerged sample (approximately 3-foot water depth) was collected approximately 75 feet from the shoreline adjacent to Ash Pond E. It consisted of black sludge-like material that was at least 2 feet thick. • NRS 5—This submerged sample (approximately 3-foot water depth) was collected from the northerly embayment near “NRS 1” sample. It is located approximately 60 feet from the shoreline near the barge unloaded conveyor belt. The sample consisted of black sludge-like material. • NRS 6—This submerged sediment sample was collected approximately ■ 20 feet from the shoreline (approximately 1.5 foot water depth) of the NRS. It consisted of a black sludge-like material that was at least 4 feet thick. • APC 2—This submerged sediment sample was collected approximately 40 feet from the shoreline of the Ash Pond Complex (approximately 3 to 4 feet of water). It consisted of a black sludge-like material that was approximately 2 feet thick. • NRS la—This submerged sediment sample was collected approximately 50 feet from the eastern shoreline (approximately 3 to 4 feet of water) of the northwest corner of the NRS and south of the Ash Pond Complex barge conveyor. It consisted of a black sludge-like material. that was at least 2 feet thick. • NRS 4a—This submerged sediment sample was collected from the small embayment along the south end of the NRS (approximately 1.5 feet of water). It consisted of black sludge-like material that was mixed with tan silt. The black sludge was at. least 2 feet thick. (Id. at ¶ 51.) The locations of the sampling sites were identified for the Court on the Agreed Map filed by the parties for use at trial, as were the locations of the ten seeps referred to in the complaint in the State Enforcement Action. (Doc. No. 220-1.) APC 1, APC 2, and APC 4 were in the general vicinity of two seeps at issue in the State Enforcement Action. (Id.) 113.The samples were analyzed for constituents considered to be good indicators of the presence of coal ash waste. Quarles conceded that the sampling program was designed to identify the presence of contamination, not to measure the extent of that contamination. ■ (Doc. No. 227-2 (Quarles Wr. Test.) at ¶ 55.) 114. Quarles testified that constituents that are- commonly associated with coal combustion wastes .were detected in all solid waste and sediment samples that were collected from the eastern, southern, and western portions of the peninsula. Those indicators included silicon,,, boron, manganese, sulfate, iron, aluminum, barium, calcium, chromium, strontium,, arsenic, chloride, cobalt, lithium, selenium, sodium, and sulfur. (Id. at ¶ 57.) 115. By way of example, East -Side 1— located to the east of Ash Ponds A and B, not in the vicinity of any of the ten seeps mentioned in Tennessee’s State Enforcement Action complaint—exhibited what Quarles identified as elevated levels of aluminum, barium, boron, lithium, sodium, strontium, and sulfur. Among other chemicals, East Side 1 showed a boron concentration of 52 mg/kg, whereas the Bartons Creek Reference sample showed a boron concentration of <1.3 mg/kg. (Id at ¶ 58.) 116. East Side 2—-located downstream from East Side 1 and to the southeast of Ash Pond A, not in the vicinity of any of the ten seeps mentioned in Tennessee’s State Enforcement Action complaint—exhibited what Quarles identified as elevated levels of aluminum, barium, boron, chromium, iron, lithium, manganese, and strontium. For example, the Bartons Creek Reference sample showed a manganese concentration of 360 mg/kg, whereas East Side 2 showed a manganese concentration of 700 mg/kg. (Id.) ' 117. NRS 4—located immediately adjacent to the Non-Registered Site, not in the' vicinity of any seep mentioned in the State Enforcement Action complaint—exhibited what Quarles identified as elevated levels of arsenic, barium, boron, iron, sulfur, and sulfate. For example, the Bartons Creek Reference sample showed an iron concentration of 26,000 mg/kg, whereas NRS 4 showed an iron concentration of 230,000 mg/kg. (Id.) 118. The other sampling locations similarly showed what Quarles ■ identified as elevated levels' of chemicals tending to indicate the presence of coal ash waste. The particular chemicals present ■ in elevated levels and not present in elevated levels varied from location to location. (Id.) Boron, however, was present at elevated levels in all of the Gallatin Plant shoreline sediment samples, but was virtually nonexistent in the Bartons Creek Reference sample. Arsenic concentrations from the TVA shoreline samples were higher than the reference sample in over two-thirds of the on-site sediment samples. (Id. at ¶ 59.) 119. Sulfate concentrations from TVA shoreline samples were, in some instances, up to 180 times higher than the reference sample. Sulfur concentrations from TVA shoreline samples were, in some instances, up to 15 times higher than the reference sample. Iron concentrations from TVA shoreline samples were, in some instances, up to 10 times higher than the reference sample. (Id.) - ■ 120. Quarles also presented February 2015 aerial photography depicting reddish-brown coloration in the Cumberland River adjacent to the Non-Registered Site. Quarles testified that such coloration'can be indicative of coal combustion waste contaminants. (Id. at ¶ 49 & J. Ex. 78.) ‘ 121. Quarles concluded, based on the sediment sampling, that coal ash waste has been released from the Gallatin Plant at areas adjacent to both the Ash Pond Complex and the Non-Registered Site. (Doc. No. 227-2 (Quarles Wr. Test.) at ¶60.) 122. Quarles testified that he had reviewed and agreed with the written testimony of Groves and Sulkin. (Doc. No. 235 (Tr. Day 2) at 7.). 123. On cross examination, Quarles conceded that- his • sampling could not determine how long the materials he obtained had been-in the river or how they reached the river. (Doc. No. 234 (Tr. Day 1) at 186.) 124. Quarles also conceded that the flows he observed at East Side 1 and 2 were exiting to the river through porous soil, as opposed to a bedrock conduit visible from his vantage point. (Id. at 186-87.) He further conceded that he had previously referred to those locations as “seeps.” (Id. at 187-88.) 125. Regarding the Non-Registered Site, Quarles conceded that sampling locations NRS 2 and 6 were in the vicinity of a documented 1974 escape of coal ash. (Id. at 191.) 126. TVA also directed Quarles to a 1978 TVA memorandum discussing the repairs to the leaking Ash Pond Complex, which stated, “No correlation between the [water] levels or with rainfall could be found since early June 1978, apparently indicating that no hydraulic connection between the pond and the river presently exists. Similar data obtained for August 1977 (pri- or to the repair work) showed a strong correlation between pond and lake water levels.” (J. Ex. 89 at TVA_GAF_0011333.) Quarles conceded that he did not include that, conclusion in his testimony. (Doc. No. 234 (Tr. Day 1) at 207.). 127. Similarly, a: 1979 letter from the Director of Power Production for either TVA or the Plant, describing the 1978 repairs, claimed that “all the holes or low areas where leakage might be suspected were filled with either rock and clay or coarse ash or a combination of these materials,” and that ultimately “the progressive rising of the water ... leads us to believe the complete sealing of the pond has been achieved,” (J. Ex. 88 at TVA_GAF_0011330.) The same letter did, however, acknowledge the need to “closely watch the pond for any signs of further leakage.” (Id. at TVA_GAF_0011331.) Quarles conceded that he did not acknowledge the letter’s assessment in his testimony. (Doc. No. 234 (Tr. Day l)at 207.). On re-direct, ‘ he went into more detail and echoed Groves’ assessment that the 1978 repairs would have been inadequate to prevent additional sinkholes-from forming. He also suggested that water could potentially bypass the repairs. (Doc. No. 235 (Tr. Day 2) at 20-21.). 128. Finally, Quarles conceded that he had, in the past, used derogatory language to refer to' TVA and its attitude toward its environmental stewardship, including characterizing one TVA statement as suggesting TVA personnel were “[ejither ... idiots or ... lying.” (Doc. No. 234 (Tr. Day 1) at 214.) TVA also sought to undermine Quarles’ credibility with citation to' details surrounding other litigation in which he was involved, but, without sufficient context, the Court was unable to give significant weight to that evidence. (Id. at 220-28.) 129. Based on its direct observation of his demeanor, candor, and responsiveness, the Court found Quarles to possess some credibility, albe