# Tennessee Clean Water Network v. Tennessee Valley Authority

> District Court, M.D. Tennessee · August 4, 2017 · 273 F. Supp. 3d 775

URL: https://www.frixlaw.com/law-library/cases/7245118

## Case

- **Full name:** TENNESSEE CLEAN WATER NETWORK and Tennessee Scenic Rivers Association v. TENNESSEE VALLEY AUTHORITY
- **Court:** District Court, M.D. Tennessee
- **Decided:** August 4, 2017
- **Citations:** 273 F. Supp. 3d 775
- **Precedential status:** Published
- **Opinion:** Opinion of the court by Crenshaw
- **Judges:** Crenshaw
- **Cited by:** 3 later opinions in the Frix Law Library

## Citator (automated)

- No negative treatment found by the automated citator. That is not the same as a confirmation that the case is good law; read the citing cases.
- Full citator and citing cases: https://www.frixlaw.com/law-library/cases/7245118

## Opinion text

*781 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 *782 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 1
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.) *783 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:
*784 [[Image here]]
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 Coun *785 ty, 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:
*786 Additional monitoring requirements and conditions applicable to Outfalls 001 ... include: .
[[Image here]]
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 *787 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 *788 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.)
*789 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 *790 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 *791 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 *792 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 imple *793 menting 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, 2 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 *794 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 *795 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 lo *796 cated 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 3 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.
*797 • 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 concen *798 tration 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, *799 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, albeit with the caveats that' (1) the Court considered his opinion's in the context of his having been retained by Plaintiffs in this matter, and (2) the Court acknowledges Quarles’ apparent history of frustrations with and hostility toward TVA. The Court also notes that TVA demonstrated that Quarles’ testimony failed-to cite some aspects of TVA’s historical studies and records that could be read as undermining aspects of his conclusions. Quarles’ omissions, though relevant to the credibility and completeness of his opinions, did not wholly undermine his conclusions. Given the extensive nature of TVA’s historical documentation, it is not necessarily fatal that his-analysis failed to include all relevant citations.
130. TVA did not significantly undermine or contradict Quarles’ testimony that his sediment tests established the presence of heightened concentrations of chemicals associated with coal ash waste.
3. Testimony of Vojin Janjic
131. Vojin Janjic is a manager of the water-based systems unit of TDEC. Jan-jic’s responsibilities include overseeing the preparation and review of NPDES permits. (Doc. No. 235 (Tr. Day 2) at 30-31.).
132. Janjic received his chemical engineering degree from the University of Belgrade before studying environmental and water resources at 'Vanderbilt University. After completing his education, Janjic began work at TDEC, where he did field work for, four years before moving to the agency’s central office. (Id. at 31.)
133.: Janjic testified that he has been involved in the evaluation and issuance of thousands of NPDES permits. (Id. at 33.)
.134, Janjic described the permitting process for NPDES permits issued to individual permittees. The applicant first submits an application based on EPA-designed forms providing the required information to begin the permit application process. TDEC then prepares a draft permit, which it publishes publicly for comments. A permit is accompanied by a permit rationale, a separate document that explains TDEC’s process and reasoning for the terms, of the permit, If there are public comments in response to the draft permit, TDEC issues an addendum to rationale, which summarizes and responds to the comments, and makes any permit revisions that it deems necessary or justified based on the comments. (Id. at 33-34.)
135. Janjic testified that the rationale and addendum to rationale do not modify *800 the terms of the permit. Rather, they merely describe the process and basis for the permit. (Id. at 35.) On cross examination, in particular, Janjic repeatedly stressed that the addendum to rationale was distinct from the permit and was not itself an “enforceable” legal document, but rather merely an explanation of the reasoning and process behind the actually enforceable terms of the permit. (Id. at 56.)
136. The Gallatin Plant’s most recent NPDES Permit went into effect on July 1, 2012, and was set to expire on May 31, 2017. (J. Ex. 102 at 001.) Its previous permit had gone into effect on January 1, 2006, and was set to expire on November 29, 2009 (J. Ex. 136 at TSRA-GAF011526), but the terms of the permit were administratively continued from November 29, 2009, until the effective date of the 2012 permit (Doc. No. 235 (Tr. Day 2) at 38).
137. Janjic was involved in reviewing TVA’s permit renewal application for the Gallatin Plant, as well as drafting the permit itself. (Id. at 36.)
138. Janjic described generally the waste treatment anticipated to be performed at the Ash Pond Complex under the permit. Water mixed with coal ash waste is sluiced to the Complex. As it passes through the Complex, a process of settling occurs, whereby coal ash constituents settle out of the water. Finally, water is released at Outfall 001—the only outfall identified by the NPDES permit as being authorized for the discharge of coal ash wastewater. (Id. at 39-40.) Neither the 2012 nor the 2005 version of the permit authorizes discharge of coal ash wastewa-ter from anywhere other than Outfall 001. (Id. at 41-42, 48.)
139. It is undisputed that the leaks and seeps at issue in this case are not discharges from Outfall 001.
140. Janjic was asked how, if at all, the 2012 permit addresses the issue of seeps. Janjic pointed to a section of the permit labeled “Other Requirements,” and its subsection labeled “Dike Inspections.” (J. Ex. 102 at 025.) That subsection requires daily inspections including “observations of dams, dikes, and toe areas for obvious changes in erosion, cracks, or bulges, subsidence, seepage, wet or soft soil, changes in geometry, the depth in the elevation of the impounded water, sediment or slurry, freeboard, changes in vegetation such as overly lush, obstructive vegetation and trees, outlet controls, drains, and any other further changes which may indicate a potential compromise to impoundment integrity.” (Id. at 026.) Janjic characterized this requirement as at least in part directed toward identifying and addressing seeps. He explained that seeps raise two sets of concerns: first, that they could signify a compromise of the structural integrity of the impoundment; and second, that the seeps themselves could negatively affect water quality. (Doc. No. 235 (Tr. Day 2) at 43 - 45.)
141. The 2012 permit requires TVA to begin remediation procedures within twenty-four hours of discovering changes that indicate a potential compromise of the structural integrity of the impoundment. (J. Ex. 102 at 026.)
142. The 2006 permit was less demanding with regard to self-inspection, requiring TVA only to visually inspect the dikes for seepage on at least a quarterly basis. (J. Ex. 136 at TSRA-GAF011550.)
143. Janjic was asked whether he considered either permit to authorize discharges from seeps. He responded first that the permit speaks for itself, but added that the permits do not permit any “discharges from seeps that would be discernible flow of water.” (Doc. No. 235 (Tr. Day 2) at 46-48.)
144. Janjic did testify, however, that “[ejvery impoundment that is not [a] lined impoundment is going to have a certain *801 amount of seepage .... So -we realize that any earthen impoundment[s] are going to have a certain amount of seepage.” Janjic added, though, that “that seepage per se is not authorized or identified in an NPDES ■ permit.” (Id. at 48.)
145. On cross examination, Janjic confirmed that, when the 2012 permit was issued, TDEC was aware that the Ash Pond Complex experienced seeps. (Id. at 55.) -■
146. Janjic testified that the anticipated seepage to which he referred did not include flows through-sinkholes and fissures. (Id. at 49.) He testified that the seepage foreseen at the time of the 2012 permit’s issuance was de minimis, with inconsequential impacts. (Id. at 62.)
147. Janjic was asked about Part I.A(c) of the 2012 permit, which addresses removal of sludge 'or other materials removed from treatment works. (J. Ex. 102 at Oil.) He confirmed that the “sludge” referred to included coal ash that settled as part of the ash pond process, and that the 2006 permit contained a similar provision. (Doc. No. 235 (Tr. Day 2) at 49-50.)
148. Janjic was next asked about the sanitary sewer overflow provision of the 2012 permit, Part II.C(3.b). (J. Ex. 102 at 022.) Janjic explained that, in the context of the Gallatin Plant, that provision referred to “any wastewater at -the facility that is authorized by this permit.” (Doc. No. 235 (Tr. Day 2) at 51-52.) He conceded that the definition of the term as used in the Gallatin Plant’s permit differs from the definition used in the EPA’s NPDES Permit Writers’ Manual (J. Ex. 251), which is narrower. (Doc. No. 235 (Tr. Day 2) at 265.)
149. On cross examination, Janjic was asked about the Non-Registered Site. Jan-jic testified that the Non-Registered Site and the closed ash disposal area therein are “not a part of the NPDES permit.” (Id. at 57.) He agreed, though, that if the Non-Registered Site hypothetically discharged pollutants into navigable waters, that discharge would need to be authorized by TDEC. (Id. at 57-58.)
150. The 2012 addendum to rationale, in response to a comment, states, “Seepage is more similar to a nonpoint source discharge, as it is diffused over a wide area.” It is difficult to tell from the statement whether TDEC is referring to seepage frorh the Ash Pond Complex, seepage from the Non-Registered Site, or seepage generally. (J. Ex. 102 at 048.)
151. Based on its direct observation of his demeanor, candor, and responsiveness, the Court found Janjic to be credible and to credibly present his understanding of TVA’s permits and the permitting process,
4. Testimony of Barry Sulkin
152. Barry Sulkin .is a self-employed environmental consultant. He holds a B.A. from the University of Virginia with a major in Environmental Science, and an M.S. in Environmental Engineering from Vanderbilt University. Sulkin has worked as a consultant for over twenty-five years, prior to which he held several positions at the Tennessee Department of Health and Environment (now TDEC), including statewide manager of enforcement investigations for the Division of Water Pollution Control. (Doc. No. 161-1 (Sulkin CV) at 1-3.) He has amassed numerous publications on topics related to water pollution. (Id. at 5-9.)
153. Sulkin testified that he has significant experience and expertise in collecting and evaluating water samples. (Doc. No. 227-3 (Sulkin Wr. Test.) at ¶¶ 11-12.)
154. He also has significant training and experience related to the NPDES permitting system. (Id. at ¶¶ 13-14.)
155. Sulkin was retained by Plaintiffs to perform water and sediment sampling, as *802 well as provide his opinion, in this case. (Id. at ¶ 1.) . > •
156. The parties have stipulated and agreed that Sulkin is qualified as an expert by knowledge, skill, experience, training, or education pursuant to Federal Rule of Evidence 702. (Doc, No. 221.)
157. Sulkin took part in the collection of water and sediment samples on various dates from May 7, 2014, to August 3, 2016. He testified that all samples were collected in accordance with standard and customary state and EPA protocols for investigating leaking waste or unpermitted discharges. Samples were collected in laboratory-provided containers, with supplied preservatives included as specified by the lab. (Doc. No. 227-3 (Sulkin Wr. Test.) at ¶¶ 18-19.)
158. The purpose of Sulkin’s sampling was to identify the existence and composition of leaks—not; for example, to determine the ambient water quality ■ of the Cumberland River as a whole. Accordingly, samples were taken at locations close to the suspected leaks. Sulkin identified this as the proper protocol for his stated objective. (Id. at ¶ 21.)
159. Sampling locations were identified by analysis of historic maps and drainage patterns, as well as visual observations and conductivity readings. Conductivity—that is, the ability of water to pass an electrical current—is an indication of mineral or pollutant content of water, and commonly used as a reliable scientific method to identify potential areas of contamination such as from the ash disposal areas. Sulkin described the visual observations that led to sampling as the presence of an observable flowing discharge, wet soil, and discolored water or sediment. (Id. at ¶¶ 33-36.)
160. Sulkin testified that background or uncontaminated areas generally have eon-ductivity in the range of 50 to 250 |xS/cm, 4 while water contaminated by an ash waste discharge would have conductivity of greater levels. (Id. at ¶ 38.)
161. Sulkin’s characterization of the rela: tionship between an NPDES permit and its rationale mirrored Janjic’s: in particular, that the permit is binding and not modified by the rationale. (Id. at ¶ 61.)
162. Sulkin first discussed sampling he performed at, locations identified as APC 1 and APC 2. APC 1 and 2 are on the western bank of the peninsula adjacent to Pond E, near two seeps identified as part of the State Enforcement Action. (Id, at ¶ 62.) Sulkin has provided a photo of. APC 2 (J. Ex. 10) that he characterizes as depicting a discharge into the fiver. (Doc. No. 227-3 (Sulkin Wr. Test.) at ¶ 63.)
' 163. As part of his sampling, Sulkin took a baseline conductivity reading at a location across the river, away from any alleged coal ash discharges, and found a conductivity of 209 ps/cm, The conductivity at APC 1 was 768 ps/cm, and at APC 2 was 1,019 |xs/em. (Id. at ¶¶ 63-64.) Later testing showed still elevated, but lower, conductivity levels. (Id. at ¶ 65.)
164. Eventually, after Plaintiffs filed their 60-day notice of violation in this case, TVA apparently covered'the allegedly visible discharge at APC 2 with rip-rap. Sul-kin’s expert opinion was that this coverage did not stop the discharges, but instead merely made them harder to document and observe. (Id. at ¶¶ 66-67.) Testing showed continued elevated conductivity near the rip-rap cover. (Id. at ¶ 67.) When cross-examined about his assessment of the addition of the rip-rap, however, Sulkin conceded that he was not a professional engineer. (Doc. No. 235 (Tr. Day 2)-at 122.)
*803 165. Sulkin tested a third site in that general vicinity, APC 3. APC 3 was further from the shore and corresponded with a cloudiness and white coloration observed by Sulkin. (Doc. No. 227-3 (Sulkin Wr. Test.) at ¶ 65.)
166. Constituent testing from APC 1, 2, and 3 showed numerous chemicals suggestive of coal ash contamination at levels above- background values, including several at APC 2 that exceeded TDEC’s Domestic Water Supply Criterion. (Id. at ¶ 71; PI. Ex. 1.) Background values were calculated using the average values of publicly available state data from two water quality monitoring stations located 19.9 miles upstream of the Gallatin Fossil Plant. (Doc. No. 227-3 (Sulkin Wr. Test.) at ¶71.) TDEC has conducted regular testing to determine the ambient water quality of the Cumberland River, including the Old Hickory Lake area. (Id. at ¶ 41.)
167. A May 7, 2014 sample from APC 1 showed the following contaminants at levels elevated compared to background: chloride, cobalt, iron, manganese, nickel, sulfate, and vanadium. An APC 2 sample from the same date showed elevated levels of chloride, cobalt, iron, manganese, nickel, and sulfate. (Id. at ¶ 74.) ■
168. An August 25, 2014 sample from APC 2 showed even greater evidence of contamination, with elevated levels of aluminum, arsenic, barium, cadmium, calcium, chloride, chromium, cobalt, copper, iron, lead, magnesium, manganese, nickel,’selenium, sodium, sulfate, thallium, vanadium, and zinc. Of these, arsenic, barium, cadmium, lead, nickel, selenium, and thallium all exceeded TDEC’s Domestic Water Supply Criterion. (Id. at ¶¶ 76-77.)
169. For example, water upstream from the plant showed an average arsenic concentration of 0.00045 mg/L. The Domestic Water Supply Criterion for arsenic is 0.01 mgy/L. Sampling at APC 2 on August 25, 2014, showed arsenic at a concentration of 0.13 mg/L, thirteen times the criterion level'. (PI. Ex. 1.) -
170. At sample location APC 3 on August 25,' 2014, the following parameters exceeded background levels: aluminum, arsenic, barium, cadmium, chloride, chromium, cobalt, coppér, iron, lead, magnesium, manganese, molybdenum, sodium, sulfate, and zinc. (Doc. No. 227-3 (Sulkin Wr. Test.) at 178.)
171. Most recently, on August 3, 2016, a sample collected adjacent to the rip-rap that had been placed over top of the visible discharge identified as location APC 2 contained the following parameters above background: aluminum, antimony, arsenic, barium, calcium, chloride, cobalt, copper, iron, lead, manganese, nickel, sodium, sulfate, vanadium, and zinc. (Id. at ¶ 79.)
172. Samples taken from East Side 1 and East Side 2 also showed elevated levels o'f several contaminants. An August 25, 2014 sample from East Side 1 showed concentrations of the following contaminants in excess of the average upstream background- levels: aluminum, arsenic, barium, calcium, chloride, chromium, cobalt, copper, iron, lead, magnesium, manganese, molybdenum, nickel, sodium, sulfate, vanadium, and zinc. Compared to background levels, a sample taken from East Side 2 on the same date showed elevated levels of arsenic, calcium, chloride, manganese, and molybdenum. (PI. Ex. 1.)
173. For example, the East Side 1 sample showed an arsenic concentration of 0.0019 mg/L, over four times the background average of 0.00045 mg/L. The East Side 2 sample showed an arsenic concentration of 0.001 mg/L, over twice the average upstream level. (Id.),
174. Sulkin testified that, in his expert opinion, the surface water- samples and the sediment samples from the. waters adja *804 cent to the Ash Pond Complex demonstrate continuing leakage from the ash storage facilities at the Ash Pond Complex. (Doc. No. 227-3 (Sulkin Wr. Test.) at ¶ 83.)
175. He also testified that, in his expert opinion, this leakage is not the result of a slow seep from the walls of the ash ponds, but rather is the continuing flow of drainage and waste water through the natural drainage channel of Sinking Creek and outlets of the former Sinking Creek em-bayment of the lake, as well as through discharge of contaminated groundwater to the river. (Id. at ¶ 84.) On cross examination, however, Sulkin conceded that he was not a geologist or expert on karst. (Doc. No. 235 (Tr. Day 2) at 112.)
176. Sulkin testified that he considered the leaks from the Gallatin Plant’s coal ash storage facilities to be a significant threat to public drinking water, because there is a drinking water facility a mile and a half down river from the Plant. (Doc. No. 227-3 (Sulkin Wr. Test.) at ¶ 86.) He also testified that the Old Hickory Lake area is heavily used for recreation. (Id. at ¶40.)
177. In addition to the sampling from the Cumberland River, Sulkin reviewed groundwater monitoring reports from four groundwater monitoring wells in the vicinity of the Ash Pond Complex, identified as wells 17, 23, 24, and 25. (Id. at ¶ 92.) Sulkin testified that, based on TVA’s reports, all four of these wells are downgradient of the groundwater flow from the Ash Pond Complex. (Id. at ¶ 94.)
178. Sulkin testified that TVA’s historical groundwater monitoring data showed elevated levels of several chemical indicators in each of the wells. (Id. at ¶¶ 94-97; see PL Ex. 2.)
179. Sulkin, TVA, and TDEC took part in joint sampling of the wells in July and September of 2015. This testing also showed elevated contaminant levels that, in Sulkin’s opinion, were indicative of groundwater contamination. (Doc. No. 227-3 (Sulkin Wr. Test.) at ¶ 98; see PI. Ex. 3.)
180. Data from offsite drinking wells was, in Sulkin’s analysis, similarly corroborative of groundwater contamination. (Doc. No. 227-3 (Sulkin Wr. Test.) at ¶¶ 103-08; see PI. Ex. 3.)
181. Like Quarles, Sulkin testified that aerial photography of the Cumberland River near the Non-Registered Site showed coloration indicative of coal ash contamination. (Doc. No. 227-3 (Sulkin Wr. Test.) at ¶ 115.)
182. In February of 2015, Sulkin performed water and sediment sampling at NRS 1 and NRS 4, adjacent to the Non-Registered Site. He sampled NRS 4 and NRS 6 in August of 2016. (PI. Ex. 1.) Sulkin compared the constituent levels in the water samples to the same upstream values he used for his analysis of the samples taken from adjacent to the Ash Pond Complex. (Doc. No. 227-3 (Sulkin Wr. Test.) at ¶ 122.)
183. NRS 1, 4, and 6 all had several contaminants in concentrations greater than the upstream average. The 2015 NRS 4 sample also had lead in a concentration exceeding the domestic water supply criterion. (J. Ex. 1.)
184. The 2015 NRS 4 sample showed the following contaminants at levels above the comparison level: aluminum, arsenic, barium, beryllium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, nickel, sodium, sulfate, vanadium, and zinc. The sample level for aluminum was 10 mg/L—100 times the average background level. (Doc. No. 227-3 (Sulkin Wr. Test.) at ¶ 124.)
185. A 2016 NRS 4 sample showed the following contaminants at levels above the comparison level: aluminum, antimony, calcium, cobalt, copper, iron, magnesium, *805 manganese, nickel, selenium, sulfate, and zinc. (Id. at ¶ 125.)
186. The 2016 NRS 6 sample showed the following contaminants at levels above the comparison level: aluminum, antimony, arsenic, barium, calcium, copper, iron, manganese, vanadium, and zinc. (Id. at ¶ 126.) Sulkin also examined material from the river bottom at NRS 6 with a microscope. He observed eenospheres, which he testified demonstrated the presence of coal ash in the river. (Id. at ¶¶ 129-30.) On cross examination, however, Sulkin conceded that he had offered no opinion with regard to when that ash was deposited. (Doc. No. 235 (Tr. Day 2) at 115.)
187. Sulkin’s expert opinion was that the elevated contaminant levels in the River adjacent to the Non-Registered Site were the result of continuing discharge of contaminated groundwater into the river or of possible direct discharge into the Cumberland River from the Site. (Doc. No. 227-3 (Sulkin Wr. Test.) at ¶ 144.)
188. Sulkin also reviewed TVA’s groundwater monitoring data for the area surrounding the Non-Registered Site and took part in further groundwater sampling. The sampling found a number of contaminants in levels higher than TVA’s comparison wells. (Id. at ¶¶ 138-39.)
189. Sulkm’s expert opinion was that the elevated contaminant levels in the groundwater surrounding the Non-Registered Site were the result of leaks and discharges from the unlined sides and bottom of the Site. (Id. at ¶ 143.)
190. On cross examination, Sulkin conceded that, prior to the Court’s ruling that it would not consider claims based on purely seep-based discharges, he had referred to his sampling locations as “seeps.” By the time of trial, he did not use that terminology. Sulkin explained that he had been using “seep” to refer generieally to discharges. (Doc. No. 235 (Tr. Day 2) at 114-15.) Although the Court notices this discrepancy, it also notes that, prior to the Court’s ruling, there had been little reason for Plaintiffs’ experts to draw express distinctions between discharges that were seeps alone and those that were not. Accordingly, the Court finds Plaintiffs’ experts early use of imprecise terminology relevant but not' dispositive. The Court also notes that, as TVA itself has emphasized, Sulkin is not a geologist or expert in karst.
191. TVA’s cross examination also focused on Sulkin’s decision- to use “judgmental sampling”—targeted sampling based on professional judgment—as opposed to “probabilistic sampling,” which would have been more conducive to drawing broad inferences from the resultant data, such as inferences about the" general ambient water quality of the river in the relevant area. Sulkin explained that he had used his professional judgment to design a sampling methodology with his particular objective—identifying discharges—in mind. (Id. at 118-20.) The Court found Sulkm’s explanation convincing, but notes that that explanation does significantly limit the uses to which his sampling can be put. Because Sulkin’s samples wer,e targeted and not part of a probabilistic model, they provide only snapshots of particular moments and particular locations on--the river.
192. Based on its direct observation of his demeanor, candor, and responsiveness, the Court .found Sulkin to be generally credible, albeit with the caveat that the Court considered his opinions in the context of his having been retained by Plaintiffs in this matter. The Court also noted that TVA- effectively demonstrated - that Sulkin’s sampling strategy was targeted at the narrow purpose of identifying or confirming leaks, and therefore provided limited basis for drawing conclusions about *806 the extent or severity of the leaks, or their effect on the water quality of the river.
5. Testimony of Albert Hudson, Jr.
193...Albert Hudson, Jr., is a retired pipefitter living on Odom’s Ben Road, near the Gallatin Plant. He testified that he relies on well water. Hudson testified that he was made aware that his well had become contaminated and would require filtration. (Doc. No. 235 (Tr. Day 2) at 125-30.) The Court found Hudson credible, although his testimony had minimal relevance to the contested issues in this case.
6. Testimony of Dr. Avner Vengosh
194. Dr. Avner Vengosh is a tenured professor in the Division of Earth and Ocean Sciences of the Nicholas School of Environment at Duke University, where he teaches courses including Introduction to Hydrogeology and International Water Resources. He holds a Ph.D. in Environmental Geochemistry from Australian National University and previously received M.Sc. and B.Sc. degrees from Hebrew University of Jerusalem. He serves on’the editorial board of the international journal Environmental Science and Technology and as an associate editor of the international journal Applied Geochemistry. (Doc. No. 160-1 (Vengosh CV) at 1-2, 24.) Ven-gosh has amassed a body of honors, grants, and publications indicative of significant expertise in the fields of hydro-geology, geochemistry, and environmental science. (Id. at 2-29.)
195. Vengosh was asked by Plaintiffs to provide analysis and opinion related to this proceeding. Vengosh stated that he has never testified as an expert witness in a legal proceeding before and was not compensated for his opinions in this case. He stated that his motivation for involvement ■in the matter was to conduct scientific research for publication. Counsel for Plaintiffs did, however, contribute funding to Vengosh’s laboratory that was used to compensate graduate students for their work under his supervision and to pay laboratory costs for the research. (Doc. No. 228-1 (Vengosh Wr. Test.) at ¶¶ 1-6.)
196. The parties have stipulated and agreed that Vengosh is qualified as an expert by knowledge, skill, experience, training, or education pursuant to Federal ■Rule of Evidence 702. (Doc. No. 221.)
197. Vengosh testified that it is his expert opinion, based on review of data regarding groundwater and surface water quality, on the analyses performed by his laboratory under his supervision, and on his knowledge and experience, that coal ash from both seeps and groundwater conduits has contaminated water at the Galla-tin Fossil Plant and is discharging to surface water arid into the groundwater at the site at, locations other than Outfall 001. (Doc. No. 228-1 (Vengosh Wr. Test.) at ¶7.)
198. Vengosh testified that the presence of boron has been utilized in many studies as a reliable indicator of coal ash pollution. There are, however, other potential sources of boron. Accordingly, Vengosh explained, identifying coal ash contamination can be aided by identifying certain isotopic ratios that are in particular indicative of coal ash. (Id. at ¶¶ 11-22.)
199. Vengosh’s laboratory has sampled coal ash effluents from ten coal fired power plants in North Carolina and Tennessee. All of the coal ash effluents exhibited elevated boron concentrations and similar ratios between the two naturally occurring stable isotopes of boron, B-10 and B-11. (Id. at ¶¶ 14, 24.)
200. Vengosh and co-authors have published their research on boron and strontium isotopic fingerprints of coal combustion residuals. (Id. at ¶¶ 27-28 & n.1.)
201. Under Vengosh’s direction, a member of-his laboratory collected surface wa *807 ter samples from the area around the Gallatin Plant in June of 2015. One groundwater sample was also collected from Hudson’s private well. (Id. at ¶¶ 32-33.) A member of Vengosh’s lab also trained Sulkin in taking groundwater samples, and Sulkin sent groundwater samples to Vengosh for analysis. (Id. at ¶34.) All samples were analyzed at Ven-gosh’s laboratory, under his supervision and consistently with EPA methodology. (Id. at ¶ 35.)
. 202. One of Vengosh’s samples, which he referred to as GT-6, was in the location of East Side 2. Based on its low strontium and boron levels, as well as its boron and strontium isotopic ratios, Vengosh concluded that this sample was unimpacted by coal ash and adopted it as a reference sample. (Id. at ¶ 43.)
203. Another sample, GT-7, was in the location of East Side 1. It also had a low boron concentration, leading’Vengosh to conclude that the sample showed no evidence of contamination from coal ásh. (Id. at ¶ 53.)
204. Sample GT-2 was taken on the west side of the peninsula, significantly to the north of/downstream from most of the samples taken in this case, but still to the south of/upstream from Outfall 001. Its boron concentration was also low, which Vengosh concluded showed no evidence of contamination from coal ash. (Id.)
205. Vengosh’s samples GT-3 and GT-4 were close to APC 1 through 4 and the two nearby seeps included' in the State Enforcement Action. These samples showed very high concentrations of boron arid strontium, as well as boron isotopic ratios indicating the presence of coal ash. (Id. at n 45-46.)
206. Vengosh’s sample GT-5 was collected from a discharge in the area of the Non-Registered Site, near NRS 3 and NRS 4. It showed high concentrations of boron and strontium, as well as boron and strontium isotopic ratios indicating the presence of'coal ash. (Id. at ¶ 47.) '
207. In addition to the elevated concentrations of boron and strontium, GT-3, GT-4, and GT-5 had relatively high levels of other elements known to be associated with coal ash, including sulfate, calcium, manganese, and iron. GT-4 was alsti high in arsenic. (|d. at ¶ 48.)
208. Vengosh’s analysis also found elevated levels , of coal ash. constituents in sampled wells. (Id. at ¶ 63.) Boron concentrations and isotopic rations indicating coal ash contamination were particularly pronounced in wells associated with the Non-Registered Site. (Id. at ¶¶ 66, 70.)
209. Vengosh’s results were published in an article entitled “Evidence for Coal Ash Ponds Leaking in the Southeastern United States” in the peer-reviewed journal Environmental Science & Technology in 2016. (Id. at ¶ 73.)
210. Based on his results, Vengosh concluded that water contaminated by coal ash from the Ash Pond Complex and the Non-Registered Site is. discharging into the groundwater and surface water at the Gallatin Fossil Plant. (Id. at ¶ 100.)
211. Finally, at the direction of the Court, Vengosh testified about the natural variability of water sampling. He explained, “Every day, every minute of sampling would you get absolute different concentration. It’s reflecting the different mixing relationship, mixing—[the] different dilution at the time of the sampling. It’s not like you get always the same num-bér. You can get different variation even the same site if you come back tomorrow ...(Doc. No. 235 (Tr. Day 2).at 163.) The attenuation of pollutants by the river itself can also account.for significant differences in concentrations: “[W]e have a huge dilution [by] the river. So because one sample had a half a percent more of *808 river water in this blend, you would have totally different numbers, totally different values.” (Id.) What is key, Vengosh explained, is to identify significant differences between a sample and the background sample. (Id.)
212. Based on its direct observation of his demeanor, candor, and responsiveness, the Court found Vengosh to be highly credible.
7. Testimony of Dr. Dennis Lemly
213. Dr. Dennis Lemly holds M.S. and Ph.D. degrees in Biology from Wake Forest University (“Wake Forest”). Until his retirement in 2016, he held dual appointments as a Research Fisheries Biologist with the United States Forest Service and as a Research Associate Professor of Biology at Wake Forest. Lemly has amassed a number of publications tending to demonstrate significant expertise in the impacts of pollution on aquatic life. (Doc, No. 162-1 (Lemly CV) at 1-27.)
214. Lemly was retained by the Plaintiffs to review and analyze information, provide his opinion, and testify in this matter. (Doc. No. 228-2 (Lemly Wr. Test.) at ¶1.)
215. The parties have stipulated and agreed that Lemly is qualified as an expert by knowledge, skill, experience, training, or education pursuant to Federal Rule of Evidence 702. (Doc. No. 221.)
216. Lemly reviewed the following documents: (1) TVA’s 2010-2012 Biological Monitoring Studies reports (J. Ex. 56, 57); (2) the Gallatin Fossil Plant NPDES Permit issued in 2012; (3) TVA’s Discharge Monitoring Reports for the Gallatin Fossil Plant, submitted to TDEC under its NPDES permit for the years 2005 through 2015; (4) TVA’s Gallatin Fossil Plant groundwater monitoring data for the year 2015, as submitted to TDEC; (5) the 2012 Groundwater Monitoring Report issued by ARCADIS (J. Ex. 55); (6) surface water, groundwater, and sediment sampling data provided by SELC (J. Ex. 8); and (7) a 2013 Environmental Integrity Project report titled “TVA’s Toxic Legacy,” which compiles public domain pollutant data for coal ash sites, including the Gallatin Fossil Plant. (Doc. No. 228-2 (Lemly Wr. Test.) at ¶ 6.)
217. Lemly testified that it was his expert opinion, based on review and analysis of the available data, that selenium is being released at the Gallatin Fossil Plant to surface waters and groundwater, and that there is a high likelihood that selenium toxicity is occurring in fish and aquatic life at the Gallatin Fossil Plant. (Id. at ¶9.)
218. Selenium is recognized by the United States Environmental Protection Agency as a primary pollutant in coal ash. (Id. at ¶ 11 (citing Fact Sheet, Aquatic Life Ambient Water Quality Criterion for Selenium in Freshwater 2016 (“EPA Fact Sheet”) (J. Ex. 58).)
219. The EPA has stated that that selenium “bioaccumulates in the aquatic-food chain and chronic exposure in fish and aquatic invertebrates can cause reproductive impairments (e.g., larval deformity or mortality). Selenium can also adversely affect juvenile growth and mortality.” (J. Ex. 58 (EPA Fact Sheet) at TSRA-GA076499-500.)
220. Lemly testified that the EPA has been influenced by his own research related to coal ash contamination in North Carolina. Those studies showed that concentrations of waterborne selenium less than 5 ug/L, released from coal ash, accumulates in lakes and poisons fish. Lemly explained that this bioaccumulation continued after the selenium discharges themselves had ceased. Lemly’s research was published in the journal Ecotoxicology and Environmental Safety. He credits the research as a major factor in the EPA’s 2016 decision to impose more stringent *809 freshwater criteria for selenium. (Doc. No. 228-2 (Lemly. Wr. Test.) at ¶¶ 14-15.)
221. Bioaccumulation occurs when an organism absorbs a substance at a rate faster than the rate at which the organism excretes the substance. Once consumed, dietary selenium readily accumulates in tissues, sometimes to levels several thousand times the initial waterborne concentration to which the organisms are exposed. Selenium is also passed from parent fish to their offspring in the eggs as- a consequence of the contaminated diet the parent fish consume. Selenium thén accumulates in the egg yolk of the fish embryo. Once eggs hatch, the selenium is absorbed into tissues, where it alters the formation of proteins, resulting in distorted and misshapen bones and other tissues. Affected embryos may die before they can hatch, or they may hatch alive but with identifiable deformities. (Id. at ¶¶ 21-26.)
222. Lemly presented.photographic examples of fish with skeletal deformities typical of selenium toxicity. Those examples, however, did not come from any waters affected by the Gallatin Plant. (Id. at ¶¶ 28-35.) On cross examination, he confirmed that he' had not identified any deformed fish at Old Hickory Lake. (Doc. No. 235 (Tr. Day 2) at 201.)
223. The examples Lemly provided did, however, provide general background about the potential risks associated with coal ash contamination in certain levels. For example, Lemly discussed coal ash contamination from unlined pits in North Carolina’s Belews Lake. He produced photographs of fish from--Belews Lake with significant skeletal deformities apparent to the naked eye. According to Lemly, the selenium toxicity at Belews Lake caused the total elimination from the lake of nineteen species of fish. Only three species remained. (Doc. No. 228-2 (Lemly Wr. Test.) at ¶¶ 30-34.)
224. Lemly explained that a large-scale dying off of fish due to selenium toxicity often manifests subtly at first, because the deaths of unhatched embryos or newly hatched fish goes unnoticed. Accordingly, a fish population may be suffering significantly from selenium exposure without there ever being a large-scale, easily noticed fish kill event, such as the appearance of large numbers of dead fish on the surface of the water. (Id. at ¶ 38.)
225. Lemly testified that it is difficult to draw inferences about fish population levels in the Old Hickory Lake area, because it is an open aquatic system—meaning that fish pass freely into, through, and out of it—as w'ell as due to the effect of state and/or federal fish stocking programs intended to augment the population of sport fish. (Id. at ¶¶ 41-45.)
226. Lemly identified Old Hickory Lake as a “lentic” system, meaning a water habitat with slow-moving or standing water. In contrast, a “lotic” system is a system with more rapidly flowing water. Bioaccu-mulation of selenium is facilitated by lentic systems. For this reason, the EPA has imposed a more stringent selenium criterion for lentic systems than for lotic systems (Id. at ¶¶ 55-59.)
227. Lemly described - an appropriate methodology for determining the impact of selenium on fish in Old Hickory Lake based on detailed studies of newly hatched fish. It does not appear, however, based on Lemly’s testimony, that such an investigation had been performed at the time of his analysis. (Id. at ¶ 48.)
228. Lemly has, however, developed a hazard rating model for the evaluation of the aquatic hazard posed by selenium. That model has been published in peer-reviewed scientific literature. (Id. at ¶ 60.) As relevant to this case, Lemly evaluated the aquatic ecological hazard of selenium being discharged at the Gallatin Fossil *810 Plant by comparing the concentrations of selenium measured in site sampling data with toxic threshold values and biological effects criteria for fish and other aquatic life and aquatic-dependent wildlife. (Id. at ¶ 62.) Because the EPA and the states have not established biological effects criteria for wildlife, Lemly relied on peer-reviewed scientific literature for wildlife toxicity data. (Id. at ¶ 65.)
229. On cross examination, TVA pressed Lemly on whether his analysis in this case truly conformed ■ to the peer-reviewed methodology that he had previously developed. In particular, Lemly admitted that his protocol called for data not only from water and sediment but also certain organisms and both fish and bird eggs. While the model may still be used if only one of those three additional data sources is missing, a lack of two or. more contemplated data sources means that the analysis, under Lemly’s published model, is not complete. The analysis in this case relies only on surface water, groundwater, and sedi: ment sampling, which does not comply with Lemly’s published model. (Doc. No. 235 (Tr. Day 2) at 194-95.) On re-direct, Lemly explained that, although the published model1 does call for reliance on several factors, each factor does have its own hazard rating scale, and thus the factors are capable of being applied independently. (Id., at 217.)
230. Lemly’s model characterizes the degree of hazard for' a particular area as Low, Moderate, or High. These hazard ratings reflect Lemly’s assessment of the expected effects of acute and chronic waterborne exposure and acute and chronic dietary exposure to contaminants. A “Low Hazard” rating reflects contaminant concentrations that at least equal or exceed one-fourth of the chronically toxic concentration. A “Moderate Hazard” rating reflects concentrations that at least equal or exceed one half of the chronically toxic concentration. A “High Hazard” rating reflects concentrations that at least equal or exceed acutely or chronically, toxic levels. (Doc. No. 228-2 (Lemly Wr. Test.) at ¶¶ 66-68.)
231. Lemly’s analysis designated selenium as High Hazard in the area of the Gallatin Plant—meaning that he considered the selenium concentration to equal or exceed acutely or chronically toxic levels. He testified that this concentration of selenium would be expected to cause toxicity in a wide range of animals at all levels of the area’s ecosystem, including fish such as minnows, darters, sunfish, and bass; amphibians including toads, frogs, and salamanders; crustaceans such as amphi-pods and crayfish; mollusks such as mussels, clams, and snails; and inséets and worms. (Id. at ¶¶ 85-86.)
232. Specifically, Lemly concluded that selenium is present in the surface water discharges from the Gallatin'Fossil Plant at up to 75 parts per billion, 50 times what he identified as the threshold value for bioaccumulation to toxic levels in "the tissues of aquatic life. (Id. at ¶ 84.)
233. He similarly designated selenium as High Hazard in the area’s groundwater, concluding that the groundwater concentrations exceed up to 45 times the threshold for bioaccumulation in fish and aquatic life. (Id. at ¶¶ 90-92.)
234. In Lemly’s expert opinion, the polluted groundwater at the Gallatin Fossil Plant poses a grave threat to aquatic life when it reaches the surface. (Id at ¶ 93.)
235. Finally, Lemly’s analysis also gave a High Hazard designation to selenium in the sediment samples. Selenium is present in sediment at the Gallatin Fossil Plant at concentrations up to 130 parts per million, 65 times higher than the threshold concentration for toxic bioaccumulation in aquatic life. (Id. at ¶¶ 96-97.) Sediment, Lemly *811 explained, is a significant, route by which físh and aquatic life are exposed to coal ash pollutants, in-particular for sediment-dwelling creatures-such as catfish, frogs, and crayfish. (Id. at ¶ 98.) ;
236. On cross examination,- Lemly confirmed that, in reaching his conclusions, he relied on the highest .available concentration readings, not average or median concentration levels based on all of the available sampling. (Doc. No. 235 (Tr. Day 2) at 198.)
, 237. Lemly also conceded that the toxic concentration values he identified and relied upon were more stringent than Tennessee’s water quality criteria. (Id. at' 199-200.)
238. Based on its direct observation of his demeanor, candor, and responsiveness, the Court found Lemly to possess some general credibility on the foundational question of whether selenium presents risks of bioaccumulation and toxicity in fish and aquatic life, although the Court does note that Lemly appears to take an aggressive view of when that risk becomes significant. Although the Court did find Lemly’s hazard analysis relevant to this case, the Court found that the reliability of his conclusions was undermined significantly by the lack of corroborating data from fish tissues or eggs, as well.,as the lack of evidence from the morphology of any fish or aquatic life taken from the Old Hickory Lake area.
8. Testimony of Britton Dotson
239. Dotson is an environmental fellow at TDEC’s Division of Water Resources. He described his responsibilities as varied, but generally drawing on his experience and knowledge related to geology and/or waste management. Dotson has a bachelor’s degree in Geology and a master’s in Geography from WKU. (Doc. No. 236 (Tr. Day 3) at 4-5.) He testified that his education included an emphasis in karst, in particular in WKU’s graduate program, where Dotson worked with Dr. Nicholas Crawford at the- Center for Cave and Karst Studies. (Id. at 6.)
240. In the six months preceding the trial, the majority of Dotson’s work for TDEC involved TVA, with the bulk of it consisting of work related to the Gallatin Plant. He estimated that he had visited the Plant twenty to thirty times. (Id. at 6.)
241. When asked if he had “seen karst features at the Ash Pond Complex,” Dotson replied, “I’ve seen karst features in that part of the facility.” (Id at 7.)
. 242. Dotson testified that he had seen karst features both to the north of the Ash Pond Complex and to the south of the Ash Pond Complex. (Id.) When asked if these features included sinkholes, fissures, vertical, joints, or caves, he replied, “All of the above.” (Id at 8.)
243. When asked if he had seen karst features within the Ash Pond Complex, he responded:
I have seen indications of solutionally developed bedrock in the western portion of Pond E. So—that’s not to say that I’ve seen open features or that sort of thing, but—but rock that develops in that form is typical of a’ karst process. So I have observed that within the— within Pond E.
(Id.) He testified that it would be difficult to directly observe karst features within the Ash Pond Complex because it is covered with ash.- (Id. at 11.)
244. Dotson testified that in November of 2016, he was at the Gallatin Plant and observed a geologic feature that concerned him in an exposed area of Pond E. Dotson described what he observed as a “scarp”— a type of feature formed by an abrupt change or drop'in materials. (Id. at 15-17.) He characterized the feature as “indicative of what I would expect if there’s been a *812 collapse of material.” (Id. at 16.) Dotson testified that it is common, in karst areas, for a void to develop underneath surface material, and for that material then to collapse into the void, leaving a “telltale scarp.” (Id. at 17.)
245. When asked if, to his knowledge, karst features had developed in the Ash Pond Complex in the past, Dotson replied that they had. When asked if those features had been repaired, he replied, “Some of them.” (Id. at 19.)
246. Dotson testified that he had been informed by TVA that some recent groundwater testing had found arsenic levels that exceeded EPA maximum contaminant levels (“MCLs”) in multiple wells. (Id. at 23-24.)
247. Dotson also testified about recent well water data he had reviewed. He testified that the water levels in the wells showed a “very immediate response” to changes in the Cumberland River suggestive of a direct hydrological connection such as a conduit, rather than merely through porous material. 5 (Id. at 29-30.)
248. On cross examination, Dotson conceded that he does not know whether or not Pond E is losing any water, from the potential karst feature he identified or otherwise. (Id. at 33.)
249. Based on its direct observation of his demeanor, candor, and responsiveness, the Court found Dotson to be generally credible.
C. TVA’s Evidence at Trial
1. Testimony of Gabriel Lang
250. Gabriel Lang is a program manager and senior engineer with TVA contractor AECOM. He has a Bachelor of Science degree from the University of South Florida, with a major in civil and geotechnical engineering, and has performed graduate studies in geotechnical engineering at the University of Pittsburgh. He is a licensed civil engineer in a number of states, including Tennessee. Lang has substantial professional experience with projects involving coal combustion residual impound-ments and landfills. Among the issues Lang has experience addressing is karst mitigation. (Doc. No. 229-1 (Lang Wr. Test.) at 1-2.)
251. Lang currently serves as the program manager of the coal combustion product management program for TVA. Lang’s job responsibilities include oversight of a team of civil and geotechnical engineers providing engineering services related to OCR storage, closure, and management. He has been working at the Gal-latin Plant since 2009, and his job duties at Gallatin have included serving as a lead engineer, project manager, and engineer of record for projects including OCR operations, stability improvements, dry storage, and impoundment closure evaluations. (Id. at 1.)
252. In connection with this case, Lang was asked by TVA to provide his professional evaluations' as a civil/geotechnical engineer regarding the OCR management and treatment facilities at Gallatin and to evaluate Plaintiffs’ Experts’ reports and allegations. (Id. at 3.) Lang relied on his personal observations and experience, as well as TVA, AECOM, and U.S. Army Corps of Engineers records. (Id. at 4.)
253. The parties have stipulated and agreed that Lang is qualified as an expert by knowledge, skill, experience, training, *813 or education pursuant to Federal Rule of Evidence 702. (Doc. No. 221.)-
254. Lang testified that, according to the records he reviewed, TVA reported erosion of minor amounts of ash from one spillway, associated with the ponds in the area now known as the Non-Registered Site. In 1975, TVA closed the spillway, sealed it with concrete and covered the area in vegetation to prevent further erosion. (Doc. No. 229-1 (Lang Wr. Test.) at 5.)
255. Photographs taken in connection with the 1978 inspection of the Non-Registered Site documented continued erosion of the perimeter dikes adjacent to. the Cumberland River, and references to potential erosion continue to appear in records into at least the early 1980s. (Id. at 6.)
256. Lang testified that it is his expert opinion, based upon the available historical information, that the presence of localized ash in the river near the NRS spillway is relatéd to that historical erosion and is not related to TVA’s current operations at Gal-latin. (Id. at 5.)
257. However, according to the documents on which Lang relied, the Non-Registered Site simultaneously experienced both erosion and percolation of water into groundwater. He quoted a 1981 inspection as follows:
These areas are abandoned. The only water into these areas is rainfall. There is no discharge from these areds. All rainfall is evaporated or percolates into the groundwater.
The steep outside slopes have no vegetation. Erosion of these slopes is being controlled by the construction of a ridge along the outside edge of the top of the dike and sloping the top of the dike to the inside.
(Id. at 6 (quoting J. Ex. 176 at 2) (emphasis added).) Lang’s discussion of efforts to remediate the erosion problem did not suggest that they would have also eliminated the percolation of rainfall through the Non-Registered Site and into the groundwater. (Doc. No. 229-1 (Lang Wr. Test.) at’ 4-5.)
258. Lang testified that TVA’s implementation of the 1997 Non-Registered Sité closure plan included improving drainage and regrading portions of the site to prevent ponding and “excess infiltration” from surface runoff. (Id. at '7.) He conceded in his direct testimony, however, that, under current engineering standards, the 1997 closure plan would not be considered sufficient to reduce surface water infiltration of the Ñon-Registered Site. (Id.)
259. He also conceded that there are saturated conditions within the subsurface of the Non-Registered Site as a result of groundwater and surface water infiltration/percolation, and that, under these conditions, it is possible for seepage to occur from the Non-Registered Site. Any earthen dam structure would be expected to experience' some seepage, he explained. (Id. at 8.) ' ' |
260. He also explained that seepage from the Non-Registered Site fluctuates seasonally, primarily due to the varied intensity of rainfall events. (Id.)
261. AECOM, Lang testified, has identified a total of twenty-two seep locations at Gallatin, including .nine which are on or adjacent to the embankments of the Non-Registered Site. (Id. (citing J. Ex. 157 at 13-21).) Lang characterized those nine seeps as .what AECOM refers to as “Level 1” seeps, meaning that they do not represent an imminent danger to the embankment in terms of erosion but may require additional monitoring. (Id. at 8-9.) None, of the seeps, however, are currently flowing, according to Lang. (Id. at 9.)
■ 262. Lang also testified that there is no record of coal ash flowing through an embankment seep directly into the Cumberland River. (Id.)
*814 263. Lang discussed a September 2011 assessment of the structural stability of the dams at the Ash Pond Complex, performed by EPA contractors at Dewberry Consultants LLC (“Dewberry”). The assessment, presented in final form in 2013, rated Pond E as “SATISFACTORY” and Ponds A, B, C, and D as “FAIR,” meaning that they would not be considered satisfactory unless certain remedial measures were taken. (Id. at 9-10 (quoting J. Ex. 126 at 1-3).)
264. The Dam Assessment Report also noted that “seepage areas are minor and are adequately monitored.” (J. Ex. 126 at 7-11.)
265. Lang testified that the EPA issued a “Request for Action Plan” regarding the recommendations in the 2013 report, and that TVA has since formulated and completed such á plan. (Doc. No. 229-1 (Lang Wr. Test.) at 11.)
266. Lang testified that TVA’s NPDES ' Permit for the Gallatin Plant required it to submit a closure plan for the Ash Pond Complex. (Id. (citing J. Ex. 102, Ex. 6 at 23).) TVA submitted the required closure plan on September 25, 2012. (Id. (citing J. Ex. 151).) Lang served as the engineer in charge of the Preliminary Ash Pond Closure Plan. (Id.)
267. The Preliminary Ash Pond Closure Plan calls for “closure in place” of Ponds A and E, meaning that they would be closed without the underlying coal ash waste being removed and relocated. Ponds B, C, and D would remain in operation for the management of storm water runoff from upstream drainage areas. (Id. at 12.)
268. Closure in place is one of two options for the closure of surface coal ash impoundments potentially available under the EPA’s Rule for Disposal of Coal Combustion Residuals from Electric Utilities (“CCR Rule”). See 80 Fed. Reg. 21,302 (Apr. 17, 2015). The other is “closure by removal,” which, as its name suggests, involves removal of waste and decontamination of the area, (Doc. No. 229-1 (Lang Wr. Test.) at 12.)
269. According. to Lang, the Gallatin Plant’s Closure Plan estimates that closure of Pond E will be completed in 2021 and closure of Pond A will be completed in 2025. Each closure will be followed by a thirty-year Post-Closure Period during which the Plan calls for certain regular monitoring and maintenance. ■ (Id. at 14-15.)
270. In contrast, Lang estimated that closure by removal, with the excavated coal ash being moved to an on-site landfill, would take twenty-four or more years before closure would be completed. (Id. at 23.) Closure by removal would also, according to Land, require a thirty-year post-closure monitoring period. (Doc. No. 236 (Tr. Day 3) at 146.)
271. On re-direct, Lang elaborated about the potential sites to which excavated coal ash could be moved. He said that the use of the on-site landfill had been considered, but that it presented some challenges. He testified that a landfill in or near 'Mur-freesboro had also been considered, but that it was “a distance away.” He described the truck traffic necessary to use an offsite landfill as substantial, specifically offering the figure of fifty to one hundred trucks on the road a day for a period of twenty years. (Id. at 134.)
272. Lang testified that closure in place was selected because it presented the most feasible means of expediting the closure of the ash ponds. (Doc. No. 229-1 (Lang Wr. Test.) at 15.) He noted in particular that the significant amounts of deeply buried ash in the Ash Pond Complex would present safety and environmental challenges for closure by removal. (Id. at 15.) In particular, Lang testified that excavation of coal ash would create increased potential for the formation of new sinkholes *815 during the excavation process. (Id. at 25.) The need to bring-in outside soil would also give rise to the ordinary environmental and safety risks associated with increased truck traffic, such as increased greenhouse gas emissions and risk of traffic accidents. (Id. at 24.)
273. Lang testified that closure by removal was not, in his opinion, feasible, in light of the size and conditions of the Ash Pond Complex. Lang cited both the risk of increased karst activity during the excavation process as well as the lengthy period of time that he estimated would be required for closure to be completed. He testified that AECOM was not aware of any completed ash pond removal projects of the magnitude that would be required for the Gallatin Plant, with the exception of the efforts required after the massive 2008 coal ash spill near Kingston, Tennessee. (Id. at 26-27.) On cross examination, however, he conceded that as many as 70% of the individual surface impoundments in South Carolina were being closed by removal. (Doc. No. 236 (Tr. Day 3) at 109.)
274. -Lang echoed EPA guidance that the choice between closure in place, and closure by removal must be made on a case-by-case basis. He testified that it was his opinion, within a reasonable degree of scientific certainty, that closure in place via inter alia placement of a geosynthetic cap would, in this instance, meet the minimum requirements of the CCR Rule. (Doc, No. 229-1 (Lang Wr. Test.) at 18-19.)
275. Lang testified that AECOM had developed a conceptual plan for further closure of the Non-Registered Site, intended to remedy deficiencies in the Site’s prior capping and closure. The centerpiece of that plan is the placement of a geosyn-thetic cap that, Lang estimated, would reduce surface water infiltration by 99.8%. (Id. at 30-31.)
276. On cross examination, Lang conceded that recent sampling of wells in the area of the Gallatin Plant -showed some exceedances of MCLs for arsenic. (Doc. No. 236 (Tr. Day 3) at 110-11.) He also conceded that there was a history of sinkholes in the Ash Pond Complex. (Id at 113.)
277. Lang admitted that the assumptions underlying his analysis of closure in place of the Ash Pond Complex assumed water infiltration only through direct vertical infiltration of rain from directly above the closed ponds or via runoff of stormwater from immediately adjacent areas. He did not, in other words, contemplate the potential for lateral infiltration of water via groundwater flowing from farther away coming into contact with coal ash because the ash itself was in contact with or below the water table. (Id. at 118-19.)
278. Lang conceded, on cross examination, that a March 2015 document created by AECOM, on which' he had worked, including the following statements regarding Ash Pond E: “A portion of the ash is below (up to 10 feet below) the elevation of the Cumberland River”; and “If the Pond is hydraulically connected to the Cumberland River, dewatering below river level would be virtually impossible (you cannot pump the river down)[.]” The latter of these two statements was identified as a “Potential Fatal Flaw” to the 'dewatering process. (Id. at 128-29; J. Ex. 113 at 7.)
279. Lang stressed, however, that, based on subsequent investigation from wells on the Gallatin Plant site, there was no evidence of a hydrologic connection between the Pond and the Cumberland River. (Doc. No. 236 (Tr. Day 3) at 13(1)
280. On re-direct, Lang discussed. the potential scarp feature that Dotson had observed. He stated that the feature appeared to him to be an “erosional feature” rather than a sinkhole. (Id. at 135.) He testified that the feature, was being monitored photographically and that some pho *816 tographs depicted standing water atop the feature. (Id. at 136-89.)
281. Based on its direct observation of his demeanor, candor, and responsiveness, the Court found Lang to be generally credible, with the caveat that it has considered his testimony in light of his close professional relationship with TVA and his past responsibility for TVA’s development of closure strategies for the ash ponds.
2. Testimony of Dr. Neil Carriker
282. Dr. Neil Carriker has a B.S. degree in Chemistry from the University of North Carolina-Charlotte and M.S. and Ph.D. degrees in Environmenta

[Text truncated at 120,000 characters. The full text is on the page linked above.]

---

Source: Frix Law Library, https://www.frixlaw.com/law-library/cases/7245118. Public record. Not legal advice.