Sierra Club, Inc. and Conservation Law Foundation, Inc. v. Granite Shore Power LLC; GSP Merrmack LLC; and Public Service Company of New Hampshire d/b/a Eversource Energy
This text of 706 F. Supp. 3d 257 (Sierra Club, Inc. and Conservation Law Foundation, Inc. v. Granite Shore Power LLC; GSP Merrmack LLC; and Public Service Company of New Hampshire d/b/a Eversource Energy) is published on Counsel Stack Legal Research, covering District Court, D. New Hampshire primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.
Opinion
UNITED STATES DISTRICT COURT FOR THE DISTRICT OF NEW HAMPSHIRE
Sierra Club, Inc. and Conservation Law Foundation, Inc.
v. Civil No. 19-cv-216-JL Opinion No. 2023 DNH 149P Granite Shore Power LLC; GSP Merrmack LLC; and Public Service Company of New Hampshire d/b/a Eversource Energy
ORDER AND VERDICT AFTER BENCH TRIAL This case requires the court to assess a power plant’s compliance with a National
Pollutant Discharge Elimination System permit issued by the Environmental Protection
Agency in 1992. After denying a motion to dismiss and two summary judgment motions,
and partially denying a third summary judgment motion, the court conducted a bench trial
on the remaining claims that spanned roughly fourteen days.
The plaintiffs and defendants each submitted a set of proposed findings and
rulings and a trial brief before trial; the parties also jointly submitted a pre-trial statement
of agreed facts. Following trial, the parties each filed post-trial briefs and re-filed their
proposed findings and rulings with citations to the evidence in the record. With the
assistance of these materials, the court makes the following findings of fact and rulings of
law, see Fed. R. Civ. P. 52(a), resulting in judgment for the defendants on all five Counts. I. Factual Background
The following findings of fact are generally drawn from the parties’ statement of
agreed facts1 and, where indicated, the witness testimony adduced at trial or the
documents admitted into evidence.
This lawsuit concerns the operation of Merrimack Station, a steam-electric power
plant located in Bow, New Hampshire, on the western bank of the Merrimack River.2
Before delving into the details of the lawsuit, the court begins with some background
facts about the Station and its interaction with the surrounding water body.
Merrimack Station has two electrical generating units, referred to as Unit 1 and
Unit 2.3 When in operation, Merrimack Station draws water from the Merrimack River,
which it uses to cool and condense the steam it produces while generating electricity.4
The Station then discharges the heated water through a cooling canal back into the river.5
The cooling canal contains Power Spray Modules which, in the EPA’s words, “are
designed to increase the evaporative cooling of the water in the canal and, thereby, to
1 The agreed-to facts were submitted in the Joint Pretrial Submission of Agreed and Disputed Facts (doc. no. 93). Agreed-to facts are referred to as “AF” along with the associated paragraph number. 2 Doc. no. 93 at AF ¶ 1. 3 Id. at AF ¶ 2. 4 Id. at AF ¶ 3. 5 Id. at AF ¶ 5.
2 reduce the plant’s ultimate thermal discharge into the river.”6 The Station’s cooling
system is referred to as a “once-through” or “open-cycle” cooling system.7
The Station releases heated water into the Hooksett Pool—a roughly 5.8-mile long
section of the river that ranges between six and ten feet in depth.8 The Hooksett Pool is
bounded by two dams—the Garvins Fall Dam at the head of the pool, and the Hooksett
Dam at the tail of the pool.9 When released, the heated water forms a thermal “plume,”
or “an ever changing volume of water which has elevated temperature.”10 Thermal
plumes released from the Station are surface-oriented, and may vary in depth.11
The EPA describes the potential effects of the addition of heat to the river as
follows.
Depending on the amount of heat being discharged and conditions in the receiving water, thermal discharges can have a variety of adverse ecological effects because aquatic organisms and water quality may be affected in many ways by water temperature. For example, fish have optimal temperatures for growth. They also display preferences for certain water temperatures and may, if possible, leave or
6 Id. 7 Id. at AF ¶ 3. 8 Id. at AF ¶¶ 3, 5. 9 Id. at AF ¶ 6. 10 Applied Science Associates, Inc., Modeling of Thermal Plume from Merrimack Station (Pls.’ Ex. 14) at 2. 11 See, e.g., id. at 3 (temperature readings gathered during “early spring until fall 2009” from “fixed thermistor strings that monitored the top, middle[,] and bottom water temperatures at west, center[,] and east locations at various transects (stations) along the [Merrimack] River” showed that ”the observed elevated temperatures” from the Station’s thermal plumes “were primarily contained between the west and center of the River in the top to middle of the water column and not . . . on the bottom”); Responses to Comments, Public Review of Merrimack Station NPDES Permit No. NH0001465 (“2020 Response to Comments”) (Defs.’ Ex. 9) at 246 (describing the “Station’s surface-oriented thermal plume, which can hug the banks and extend down three-feet”).
3 avoid an area if water temperatures exceed their preferred levels. Furthermore, altered water temperatures may benefit certain species at the expense of other species, causing shifts in the make-up of the community of organisms in the affected water. Finally, increasing water temperatures can also affect water quality in many ways, such as by promoting algal growth or contributing to reduced levels of dissolved oxygen.12 The Federal Water Pollution Control Act, or the Clean Water Act, “established a
National Pollution Discharge Elimination System [“NPDES”] . . . that is designed to
prevent harmful discharges[,]” such as heat, “into the Nation’s waters.” Nat’l Ass’n of
Home Builders v. Defenders of Wildlife, 551 U.S. 644, 650 (2007). Since 1992, the
Station has operated under the same NPDES permit (“1992 Permit”), issued by the EPA
pursuant to the CWA. The 1992 Permit authorizes the Station’s discharge of heated water
into the Merrimack River.13
Public Service Company of New Hampshire owned and operated Merrimack
Station, and was subject to the Station’s NPDES Permit, until 2018.14 The defendant
companies, GSP Merrimack LLC and Granite Shore Power LLC, were formed in 2017
for the purpose of purchasing Merrimack Station.15 In January 2018, GSP Merrimack
purchased and assumed operations of the Station, at which point the EPA transferred the
12 EPA -New England Clean Water Act NPDES permitting Determinations for the Thermal Discharge and Cooling Water Intake Structures at Merrimack Station in Bow, New Hampshire NPDES permit No. NH 0001465 (“2011 Determinations Document”) (Pls.’ Ex. 3) at 4; see also infra Section III.D.1. 13 Doc. no. 93 at AF ¶ 8. 14 Id. at AF ¶ 9. 15 Id. at AF ¶ 10. Granite Shore Power is the sole member of GSP Merrimack. Id. at AF ¶ 14.
4 operative 1992 Permit to GSP Merrimack.16 In 2019, the plaintiffs, Sierra Club, Inc. and
Conservation Law Foundation, Inc., two environmental organizations, filed the instant
lawsuit under the citizen suit provision of the CWA, see 33 U.S.C. § 1365(a)(1). The
plaintiffs allege that the defendants have violated, and are continuing to violate, the 1992
Permit.
Five claims remain, and were the subject of the bench trial. In Counts 1-3, the
plaintiffs allege ongoing violations of each of the three elements of Part I.A.1.g of the
1992 Permit. Part I.A.1.g sets forth the following narrative thermal discharge limitation:
“The combined thermal plumes for the station shall (a) not block zone of fish passage, (b)
not change the balanced indigenous population of the receiving water, and (c) have
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UNITED STATES DISTRICT COURT FOR THE DISTRICT OF NEW HAMPSHIRE
Sierra Club, Inc. and Conservation Law Foundation, Inc.
v. Civil No. 19-cv-216-JL Opinion No. 2023 DNH 149P Granite Shore Power LLC; GSP Merrmack LLC; and Public Service Company of New Hampshire d/b/a Eversource Energy
ORDER AND VERDICT AFTER BENCH TRIAL This case requires the court to assess a power plant’s compliance with a National
Pollutant Discharge Elimination System permit issued by the Environmental Protection
Agency in 1992. After denying a motion to dismiss and two summary judgment motions,
and partially denying a third summary judgment motion, the court conducted a bench trial
on the remaining claims that spanned roughly fourteen days.
The plaintiffs and defendants each submitted a set of proposed findings and
rulings and a trial brief before trial; the parties also jointly submitted a pre-trial statement
of agreed facts. Following trial, the parties each filed post-trial briefs and re-filed their
proposed findings and rulings with citations to the evidence in the record. With the
assistance of these materials, the court makes the following findings of fact and rulings of
law, see Fed. R. Civ. P. 52(a), resulting in judgment for the defendants on all five Counts. I. Factual Background
The following findings of fact are generally drawn from the parties’ statement of
agreed facts1 and, where indicated, the witness testimony adduced at trial or the
documents admitted into evidence.
This lawsuit concerns the operation of Merrimack Station, a steam-electric power
plant located in Bow, New Hampshire, on the western bank of the Merrimack River.2
Before delving into the details of the lawsuit, the court begins with some background
facts about the Station and its interaction with the surrounding water body.
Merrimack Station has two electrical generating units, referred to as Unit 1 and
Unit 2.3 When in operation, Merrimack Station draws water from the Merrimack River,
which it uses to cool and condense the steam it produces while generating electricity.4
The Station then discharges the heated water through a cooling canal back into the river.5
The cooling canal contains Power Spray Modules which, in the EPA’s words, “are
designed to increase the evaporative cooling of the water in the canal and, thereby, to
1 The agreed-to facts were submitted in the Joint Pretrial Submission of Agreed and Disputed Facts (doc. no. 93). Agreed-to facts are referred to as “AF” along with the associated paragraph number. 2 Doc. no. 93 at AF ¶ 1. 3 Id. at AF ¶ 2. 4 Id. at AF ¶ 3. 5 Id. at AF ¶ 5.
2 reduce the plant’s ultimate thermal discharge into the river.”6 The Station’s cooling
system is referred to as a “once-through” or “open-cycle” cooling system.7
The Station releases heated water into the Hooksett Pool—a roughly 5.8-mile long
section of the river that ranges between six and ten feet in depth.8 The Hooksett Pool is
bounded by two dams—the Garvins Fall Dam at the head of the pool, and the Hooksett
Dam at the tail of the pool.9 When released, the heated water forms a thermal “plume,”
or “an ever changing volume of water which has elevated temperature.”10 Thermal
plumes released from the Station are surface-oriented, and may vary in depth.11
The EPA describes the potential effects of the addition of heat to the river as
follows.
Depending on the amount of heat being discharged and conditions in the receiving water, thermal discharges can have a variety of adverse ecological effects because aquatic organisms and water quality may be affected in many ways by water temperature. For example, fish have optimal temperatures for growth. They also display preferences for certain water temperatures and may, if possible, leave or
6 Id. 7 Id. at AF ¶ 3. 8 Id. at AF ¶¶ 3, 5. 9 Id. at AF ¶ 6. 10 Applied Science Associates, Inc., Modeling of Thermal Plume from Merrimack Station (Pls.’ Ex. 14) at 2. 11 See, e.g., id. at 3 (temperature readings gathered during “early spring until fall 2009” from “fixed thermistor strings that monitored the top, middle[,] and bottom water temperatures at west, center[,] and east locations at various transects (stations) along the [Merrimack] River” showed that ”the observed elevated temperatures” from the Station’s thermal plumes “were primarily contained between the west and center of the River in the top to middle of the water column and not . . . on the bottom”); Responses to Comments, Public Review of Merrimack Station NPDES Permit No. NH0001465 (“2020 Response to Comments”) (Defs.’ Ex. 9) at 246 (describing the “Station’s surface-oriented thermal plume, which can hug the banks and extend down three-feet”).
3 avoid an area if water temperatures exceed their preferred levels. Furthermore, altered water temperatures may benefit certain species at the expense of other species, causing shifts in the make-up of the community of organisms in the affected water. Finally, increasing water temperatures can also affect water quality in many ways, such as by promoting algal growth or contributing to reduced levels of dissolved oxygen.12 The Federal Water Pollution Control Act, or the Clean Water Act, “established a
National Pollution Discharge Elimination System [“NPDES”] . . . that is designed to
prevent harmful discharges[,]” such as heat, “into the Nation’s waters.” Nat’l Ass’n of
Home Builders v. Defenders of Wildlife, 551 U.S. 644, 650 (2007). Since 1992, the
Station has operated under the same NPDES permit (“1992 Permit”), issued by the EPA
pursuant to the CWA. The 1992 Permit authorizes the Station’s discharge of heated water
into the Merrimack River.13
Public Service Company of New Hampshire owned and operated Merrimack
Station, and was subject to the Station’s NPDES Permit, until 2018.14 The defendant
companies, GSP Merrimack LLC and Granite Shore Power LLC, were formed in 2017
for the purpose of purchasing Merrimack Station.15 In January 2018, GSP Merrimack
purchased and assumed operations of the Station, at which point the EPA transferred the
12 EPA -New England Clean Water Act NPDES permitting Determinations for the Thermal Discharge and Cooling Water Intake Structures at Merrimack Station in Bow, New Hampshire NPDES permit No. NH 0001465 (“2011 Determinations Document”) (Pls.’ Ex. 3) at 4; see also infra Section III.D.1. 13 Doc. no. 93 at AF ¶ 8. 14 Id. at AF ¶ 9. 15 Id. at AF ¶ 10. Granite Shore Power is the sole member of GSP Merrimack. Id. at AF ¶ 14.
4 operative 1992 Permit to GSP Merrimack.16 In 2019, the plaintiffs, Sierra Club, Inc. and
Conservation Law Foundation, Inc., two environmental organizations, filed the instant
lawsuit under the citizen suit provision of the CWA, see 33 U.S.C. § 1365(a)(1). The
plaintiffs allege that the defendants have violated, and are continuing to violate, the 1992
Permit.
Five claims remain, and were the subject of the bench trial. In Counts 1-3, the
plaintiffs allege ongoing violations of each of the three elements of Part I.A.1.g of the
1992 Permit. Part I.A.1.g sets forth the following narrative thermal discharge limitation:
“The combined thermal plumes for the station shall (a) not block zone of fish passage, (b)
not change the balanced indigenous population of the receiving water, and (c) have
minimal contact with the surrounding shorelines.” In Count 4, the plaintiffs claim
ongoing violations of Part I.A.1.b of the 1992 Permit, which provides that “[t]he
discharges [from the Station] shall not jeopardize any Class B use of the Merrimack
River and shall not violate applicable water quality standards.” Finally, Count 5 focuses
on ongoing violations of the annual reporting requirements in Part 1.A.13 of the 1992
Permit: “All biological and hydrological monitoring program data shall be submitted to
the [New Hampshire Department of Environmental Services], [New Hampshire Fish and
Game Department], [United States Fish & Wildlife Service], and the [EPA] Regional
Administrator by December 31 of the following year.”
16 Id. at AF ¶ 10.
5 A. Statutory framework
“Congress’ purpose as reflected in the language of the CWA is to ‘restore and
maintain the . . . integrity of the Nation’s waters.’” Cnty. of Maui, Hawaii v. Hawaii
Wildlife Fund, 140 S. Ct. 1462, 1468 (2020) (quoting 33 U.S.C. § 1251(a)). To that end,
the CWA provides that “the discharge of any pollutant by any person shall be unlawful,”
unless it complies with one of the statute’s exceptions. Id. §§ 1311(a), 1342. As one
exception, the CWA enables the EPA or an authorized state agency to issue a NPDES
permit for the discharge of pollutants, including heat, into the Nation’s waters. Id.
§ 1342(a); see also id. at § 1362(6) (identifying heat as a pollutant).
The permitting authority, in this case the EPA, is tasked to design a NPDES permit
that “assure[s] compliance with . . . applicable requirements,” consisting of technology
and water quality-based standards. See id. §§ 1342(a)(1), 1341(a)(1)-(2), 1311(b)(1)-
(b)(2). The EPA can adopt pollutant discharge limitations that deviate from those
required under technology and water quality-based standards if the “owner or operator of
the [source of the discharge] . . . can demonstrate to the satisfaction of the Administrator .
. . that any effluent limitation proposed for the control of the thermal component of any
discharge . . . [is] more stringent than necessary to assure the projection and propagation
of a balanced, indigenous population of shellfish, fish, and wildlife in and on the body of
water into which the discharge is to be made . . . .” Id. § 1326(a). This deviation is
referred to as a § 316(a) variance.
When issuing a NPDES permit, the EPA begins with a draft permit, which it issues
alongside a fact sheet “set[ting] forth the principal facts and the significant factual, legal,
6 methodological and policy questions considered in preparing the draft permit.” 40 C.F.R.
§ 124.8(a). Following that “the EPA publishes a public notice of the draft permit,” and “
[t]he public comment period opens.” City of Taunton, Massachusetts v. United States
Env’t Prot. Agency, 895 F.3d 120, 124 (1st Cir. 2018).
The EPA then reviews the comments and issues a final decision “to issue, deny,
modify, revoke and reissue, or terminate a permit.” 40 C.F.R. § 124.15(a). Along with
the final permit decision, the EPA provides a “response to comments” that “specif[ies]
which provisions . . . of the draft permit [were] changed in the final permit decision . . .
[and] [b]riefly describe[s] and respond[s] to all significant comments on the draft permit .
. . raised during the public comment period[.]” Id. § 124.17(a). Once the EPA issues a
NPDES Permit, it remains in effect for up to five years. 33 U.S.C. § 1342(a)(3),
(b)(1)(B). The permittee may apply for renewal before the Permit expires. Relevant
here, “[a]ny person who filed comments on the draft permit or participated in a public
hearing on the draft permit may file a petition for review” of a final permit decision with
the Environmental Appeal Board, contesting or raising a “specific challenge to the permit
decision . . . .” 40 C.F.R. § 124.19(a).
B. The Station’s permitting history
The EPA first issued a NPDES permit for Merrimack Station in the 1970s, and it
renewed the permit in 1985, 1992, and, most recently, in 2020.17 Each of these permits
17 Id. at AF ¶ 8.
7 focused, in relevant part, on controlling the Station’s intake of water from the river and its
release of “waste heat” or “thermal discharges” back into the river.18
In the EPA’s words, Merrimack Station underwent “different stages of permit
development, which evolved over a number of years, were driven by factual and legal
developments that altered development of the permit[,] and took time to address.”19 The
development of the 1992 Permit, the 2011 Draft Permit, and the 2020 Permit is most
pertinent to the issues in this case.
According to the EPA, the “1992 Permit set thermal discharge requirements based
on a combination of a CWA § 316(a) variance and water quality-based requirements.”20
In 1997, the then-owner of Merrimack Station, PSNH, applied for renewal of the 1992
Permit “with thermal discharge conditions matching those in the existing [1992]
[P]ermit”—that is, “conditions . . . compatible with continued year-round open-cycle
cooling at Merrimack Station.”21 The EPA administratively continued the 1992 Permit
after PSNH’s timely request for renewal, and the 1992 Permit remained “fully effective
and enforceable.”22 See 40 C.F.R. § 122.6.
18 2011 Determinations Document (Pls.’ Ex. 3) at 2; 2020 Response to Comments (Defs.’ Ex. 9) at 12 (“These three areas of regulation (i.e., setting permit requirements for cooling water withdrawals, discharges of waste heat, and discharges of other types of steam electric power plant pollutant discharges) comprise the primary areas that EPA, the State of New Hampshire, the Permittee, and the public focused on throughout permit development.”). 19 2020 Response to Comments (Defs.’ Ex. 9) at 11. 20 Id. at 12. 21 Doc. no. 93 at AF ¶ 37. 22 2011 Determinations Document (Pls.’ Ex. 3) at 2, 34.
8 In September 2011, the EPA issued a draft NPDES permit for public comment,
along with a fact sheet. Components of the fact sheet were entered into evidence at trial,
including a “Draft Permit Determinations Document,” which “present[ed] and
explain[ed] certain determinations made by EPA in support of the [2011] draft NPDES
permit.”23 The court refers to this document as the 2011 Determinations Document
throughout this Order.
The 2011 Draft Permit did not renew the same thermal limits and CWA § 316(a)
variance as in the 1992 Permit. In the 2011 Determinations Document, the EPA
explained that PSNH no longer satisfied the requirements for a § 316(a) variance, in part
because the evidence demonstrated that Station’s thermal discharge had “caused, or
contributed to, appreciable harm to Hooksett Pool’s balanced, indigenous community of
fish.”24 The EPA “instead[ ] decided that [the permit] should base thermal discharge
limits on technology-based and water quality-based requirements.”25 In particular, the
EPA concluded that one “available alternative” to the 1992 Permit conditions was to
“convert[ ] Merrimack Station’s open-cycle cooling system to a closed-cycle cooling
system using . . . mechanical draft cooling towers.”26 The cooling towers would “chill
the cooling water so that it can be re-used for condensing steam” and could potentially
23 Id. at 2. 24 Id. at 154; see also infra Section III.E.1. 25 2020 Response to Comments (Defs.’ Ex. 9) at 12. 26 2011 Determinations Document (Pls.’ Ex. 3) at 10.
9 “reduce the thermal discharges and water withdrawals by approximately 95 percent as
compared to an open-cycle system.”27
In explaining its determinations, the EPA discussed the Station’s operations. It
noted that Units 1 and 2 function as “‘baseload’ generating units,” meaning that “[o]nce
connected to an electrical grid, [each] unit’s operating parameters [is] maintained to keep
its electrical output as close as possible to its nameplate rating[,]” and “[t]he utility’s
objective is to operate the generating unit continuously at a constant electrical
output . . . .”28 In other words, baseload facilities “generally . . . operate or near full load
and on a near-constant basis.”29
Some time after the issuance of the 2011 Draft Permit, the EPA observed that the
Station had converted from a baseload facility to a peaking facility, which operates
“intermittent[ly] . . . in the winter and summer months”30 in order “to meet periods of
higher demand for electricity.”31 In August 2017, the EPA issued a “Statement of
Substantial New Questions for Public Comment,” reopening the public comment period
to address, among other questions, whether the thermal discharge limits should change
27 Id. at 3, 49 (emphasis in original). 28 Doc. no. 93 at AF ¶ 39 (quoting 2011 Determinations Document (Pls.’ Ex. 3) at 165). 29 Id. at AF ¶ 88. 30 Id. at AF ¶ 58 (quoting 2020 Response to Comments (Defs.’ Ex. 9) at 53). 31 Id. at AF ¶ 88.
10 based on the Station’s impending sale to the defendants and its “reduced” operations as a
peaking facility.32
Finally, in May 2020, the EPA issued a new NPDES Permit for Merrimack Station,
which was intended to take effect in September 2020 and “supersede[]” the 1992
Permit.33 As required, the EPA also issued Responses to Comments with the Permit.
Throughout this Order, the court refers to this document, which forms part of the trial
record, as the 2020 Response to Comments.
Roughly one month prior to the 2020 Permit’s effective date, the defendants and
the plaintiffs timely filed petitions for review before the Environmental Appeals Board,
with each party contesting different conditions in the 2020 Permit.34 A request for review
of an NPDES permit has the initial effect of staying the new permit entirely.35 Following
the submission of a request for review, the Regional Administrator determines and
notifies the parties which of the new permit’s provisions are (i) uncontested, (ii)
contested, or (iii) uncontested but inseverable from contested conditions.36 Under EPA
regulations, the uncontested conditions “become fully effective enforceable obligations of
the permit” 30 days after the Regional Administrator’s notification.37 The other two
32 Id. at AF ¶ 44; id. at AF ¶ 58 (quoting 2020 Response to Comments (Defs.’ Ex. 9) at 53). 33 See 2020 Permit (Defs.’ Ex. 8) at 1. 34 Doc. no. 93 at AF ¶ 45. 35 Id. at AF ¶ 46. 36 Id. 37 Id. at AF ¶ 47.
11 categories of conditions remain “stayed . . . pending final agency action,” and the
permittee must continue to comply with the corresponding conditions of the old permit.38
In this case, the Regional Administrator notified the parties of its determination
regarding contested conditions on September 1, 2020.39 Several of the 1992 Permit
conditions, including all of the conditions that feature in the plaintiffs’ complaint,
correspond with the contested conditions and accordingly remain in place for the duration
of the appeals process, until there is a final agency action.40 The Regional Administrator
determined that the other conditions within the 2020 Permit were uncontested and
severable, rendering those conditions effective as of October 1, 2020.41 The EAB
remanded the contested conditions to EPA Region 1 on August 3, 2021.42
C. Relevant features of the 1992 and 2020 Permits
Certain features of the 1992 and 2020 Permits, as well as differences between the
two permits, factor into the parties’ evidence and theories of the case. First, and
particularly important, Part I.A.11.a of the 1992 Permit—which remains in effect—
requires the defendants to monitor the water temperature in three locations of the river,
38 Id. 39 Id. at AF ¶ 48. 40 Id.; see also Pls.’ Ex. 71. at 3 (“As required by 40 C.F.R. § 124.16(c)(2), to the extent that conditions of the Permit are stayed, the Permittee must comply with the conditions of its existing permit (i.e., the 1992 Permit) that correspond to the stayed conditions listed above. The 1992 Permit conditions that remain in effect are: Part I.A.1.b, Part I.A.1.c, Part I.A.1.f, Part I.A.1.g, Part I.A.4.f, Part I.A.11.a-b and Part I.A.13.”). 41 Id. at AF ¶ 49. 42 Id. at AF ¶ 50; see also Pls.’ Ex. 72.
12 referred to as “N10,” “S0,” and “S4.”43 The N10 location is upstream from the Station
and captures ambient river temperatures; the S0 location is at the end of the Station’s
cooling canal; and the S4 location is .4 miles, or about 2,000 feet, downstream from the
end of the cooling canal and about two miles upriver from the lower end of the Hooksett
Pool.44 GSP has placed a single temperature probe at each of these locations, which
“record open-river surface water temperatures” at those spots.45 The probes at N10 and
S4 are removed each fall and replaced each spring, consistent with the 1992 Permit
requirement.46
Next, Ihe 1992 Permit contains narrative thermal limits, as previously noted. By
contrast, the 2020 Permit sets forth numeric thermal limits, which change over the course
of the year. According to the EPA, these limits are based on the life stage and thermal
tolerance of fish that are present in the Hooksett Pool at that time.47 Specifically, the
2020 Permit includes year-round temperature limits, including weekly average (chronic)
and daily maximum (acute) temperature limits applicable to the S4 location at specific
times of the year.48 These limits are all stayed due to the appeals process.49
43 Doc. no. 93 at AF ¶ 22. 44 Id. at AF ¶ 24. 45 Id. at AF ¶ 23. 46 Id. at AF ¶ 25. 47 See infra Section III.E.1. 48 Id. at AF ¶ 52. 49 Id.
13 The permittee is not in violation of the 2020 Permit if the thermal limits are
exceeded when the Station is not operating.50 The 2020 Permit also sets forth three
conditions (which the court refers to as “Alternative Compliance Conditions”) under
which the Station will remain in compliance, even if the Station is operating and the
temperature readings at S4 exceed the Permit’s numeric limits. The Alternative
Compliance Conditions are presently stayed, as well.51
The first two Alternative Compliance Conditions relate only to the weekly average
temperature limits. Under what the court refers to as the Capacity Factor Alternative
Compliance Condition, the Station is considered to be in compliance if its 45-day average
capacity factor is less than 40%.52 Capacity factor is a “measure of a power plant’s level
of output,” and it is “defined as the ratio of the actual production of the plant divided by
the potential production of the plant.”53 The permittee is not required to report the weekly
average temperature at Station S4 for the periods in which the capacity limitation is satisfied.54
This Alternative Compliance Condition applies from May through September.55
Under the next Alternative Compliance Condition, if the ambient temperature is
above the weekly average temperature limit, the Station remains in compliance as long as
50 Id. at AF ¶ 56. 51 Id. at AF ¶¶ 53-55. 52 Id. at AF ¶ 53. 53 Id. at AF ¶ 89. 54 Id. at AF ¶ 53. 55 Id.
14 the weekly average temperature at S4 does not exceed the temperature at N10 by more
than 2˚ C.56 A difference in temperature is referred to in shorthand as a “Delta-T”;
accordingly, the court refers to this condition as the Delta-T Alternative Compliance
Condition.
The third Alternative Compliance Condition pertains only to the daily maximum
temperature limit. If the hourly average temperature reading at S4 is found to be greater
than the daily maximum limit, the defendants are required to reduce operations or take
other measures to ensure that the temperatures at S4 comply with the numeric limits
within three hours.57
In adopting the numeric thermal limits in the 2020 Permit, the EPA explained that
the 1992 Permit’s narrative limits (which are the subject of the instant suit) were no
longer needed. Specifically, the EPA determined:
The additional backstopping provisions made some sense for the 1992 permit because a CWA § 316(a) variance was being granted in the absence of detailed thermal data and analysis, as the commenter has noted farther above. ...
Now, for the Final Permit, EPA has set stringent, specific thermal discharge limits based on a CWA § 316(a) variance that recognizes and is premised on the Facility’s much reduced operations over the last several years. EPA has also determined after an extensive, detailed analysis that these thermal discharge limits will assure the protection and propagation of the Hooksett Pool’s [balanced indigenous population]. As a result, EPA concludes that the additional narrative, water quality-based provisions are no longer needed. The Final Permit also requires significant thermal and biological monitoring. If it turns out that the Final
56 Id. at AF ¶ 54. 57 Id. at AF ¶ 55.
15 Permit’s thermal discharge limits are not adequately protective, they can be appropriately tightened in the future.58
II. Applicable Legal Standard59
As previously noted, the plaintiffs bring this suit under the CWA’s citizen suit
provision. This portion of the statute provides that “a suit to enforce any limitation in an
NPDES permit may be brought by any ‘citizen,’ defined as ‘a person or persons having
an interest which is or may be adversely affected.’” Friends of the Earth, Inc. v. Laidlaw
Env’t Servs. (TOC), Inc., 528 U.S. 167, 174 (2000) (quoting 33 U.S.C. § 1365(a), (g)).
Citizen suits may not be premised on “wholly past violations,” however. Gwaltney of
Smithfield, Ltd. v. Chesapeake Bay Found., Inc., 484 U.S. 49, 64 (1987). Rather,
plaintiffs can bring suit under this provision to redress “either continuous or intermittent
violation—that is, a reasonable likelihood that a past polluter will continue to pollute in
the future.” Id. at 57.
Moreover, as stated supra Section I, it is undisputed that the defendants assumed
ownership of the Station on January 10, 2018. Thus, the defendants were not subject to
the Permit requirements, nor liable for Permit violations, prior to January 10, 2018.
In order to prevail at this stage, the plaintiffs must prove their claims by a
preponderance of the evidence. See Carr v. Alta Verde Indus., Inc., 931 F.2d 1055, 1064
(5th Cir. 1991) (once a citizen suit under the CWA proceeds to trial, the court must
58 2020 Response to Comments (Defs.’ Ex. 9) at 332; see also infra Sections III.D, III.E, III.G. 59 The statements in this Section are rulings of law.
16 “actually decid[e] the issue[s] based on a preponderance of the evidence.”). “The burden
of showing something by a preponderance of the evidence, the most common standard in
the civil law, simply requires the trier of fact to believe that the existence of a fact is more
probable than its nonexistence before he may find in favor of the party who has the
burden to persuade the [judge] of the fact’s existence.” Concrete Pipe & Prod. of
California, Inc. v. Constr. Laborers Pension Tr. for S. California, 508 U.S. 602, 622
(1993) (internal quotations omitted).
III. Analysis60
Below, the court analyzes and makes rulings on the key legal issues in this case—
standing, the deference owed to the EPA’s relevant determinations as the agency that
issued the NPDES permit, and the merits of each of the plaintiffs’ claims.
A. Standing
The defendants assert lack of standing as an affirmative defense. To have standing
to sue, a plaintiff must have “such a personal stake in the outcome of the controversy as
to assure that concrete adverseness which sharpens the presentation of issues upon which
the court so largely depends for illumination of difficult . . . questions.” Dubois v. U.S.
Dep’t. of Agric., 102 F.3d 1273, 1280 (1st Cir. 1986) (quoting Baker v. Carr, 369 U.S.
186, 204 (1962)). In order to satisfy this requirement, “a plaintiff must show (1) it has
suffered an ‘injury in fact’ that is (a) concrete and particularized and (b) actual or
imminent, not conjectural or hypothetical; (2) the injury is fairly traceable to the
60 This Section contains both findings of fact and rulings of law, as indicated in the text.
17 challenged action of the defendant; and (3) it is likely, as opposed to merely speculative,
that the injury will be redressed by a favorable decision.” Laidlaw, 528 U.S. at 180-81.
Of relevance here, associations or organizations, like the plaintiffs, “ha[ve] standing to
bring suit on behalf of [their] members when [their] members would otherwise have
standing to sue in their own right, the interests at stake are germane to the organization’s
purpose, and neither the claim asserted nor the relief requested requires the participation
of individual members in the lawsuit.” Id. at 181.
The parties agree that certain elements of organizational standing are satisfied
here. It is undisputed that the plaintiffs “are asserting . . . their interest in protecting the
Merrimack River and its aquatic species from thermal discharges from [the] Station[,]
[and] [t]hose interests are germane to [the] [p]laintiffs’ purposes to protect the health of
New England’s and New Hampshire’s water resources.”61 The defendants’ challenge
centers instead on the injury-in-fact element of standing. According to the defendants,
none of the plaintiffs’ members has demonstrated a sufficient injury stemming from the
Station’s challenged conduct—its thermal discharges.62 The court disagrees.
The United States Supreme Court has held that “environmental plaintiffs
adequately allege injury in fact when they aver that they use the affected area and are
persons ‘for whom the aesthetic and recreational values of the area will be lessened’ by
the challenged activity.” Id. at 183. Further, “[t]he injury need not be significant; a small
61 Doc. no. 93 at AF ¶ 108. 62 Defs.’ Post-Trial Conclusions of Law (doc. no. 154) at ¶ 16.
18 stake in the outcome will suffice, if it is direct.” Dubois, 102 F.3d at 1281 (internal
quotation omitted).
In an effort to establish the requisite injury, the plaintiffs entered into evidence
affidavits from three standing witnesses, and they presented testimony from two of those
witnesses at trial. The parties agree that the standing witnesses were members of one or
both of the plaintiff organizations when the complaint was filed, and that they remain
members of the organization(s).63 Specifically, two of the witnesses, Lucinda Reid and
Benjamin MacBride, are members of Sierra Club and Conservation Law Foundation,
while the third witness, Mark Feigl, is a member of Conservation Law Foundation.64 The
court focuses its analysis on the two witnesses who testified—MacBride and Feigl—
since it was able to judge their credibility in person.
MacBride credibly testified as follows. MacBride has lived in Concord, New
Hampshire since 2013.65 Throughout his time in Concord, he has enjoyed hiking and
walking on trails along the Merrimack River with his family, including his children.66
Over the past seven years, he has also swum in the river with his family on occasion.67
MacBride learned from Sierra Club that the Station is dispensing heated water into the
river, and it “concerns” him that the discharges have “been altering the natural state of the
63 Id. at AF ¶ 108. 64 Id. at AF ¶¶ 109-10. 65 Id. (MacBride) at 32:23. 66 Id. (MacBride) at 35:17-36:4, 36:17-24. 67 Id. (MacBride) at 37:3-9.
19 river at that location.”68 He recreates in the areas upstream of the Station, and not in or
along the Hooksett Pool, because of “[g]eneral concern . . . about the presence of [the
Station] . . . and the possible effects that it has on both the river as well as the native
species and inhabitants of the river and the surrounding area.”69 According to MacBride,
“if the station were required to reduce the impact that [it is] having on the natural
environment,” his “enjoyment . . . of the river would be improved and enhanced.”70
Feigl persuasively testified to his involvement in recreational activities in and
around the river and pool, and the impact of the Station’s discharges on the same, as
follows. Feigl has lived in Concord, New Hampshire for 26 years and has an “interest in
rivers.”71 He visits the Merrimack River multiple times each week to walk, duck hunt,
canoe, kayak, and photograph the area.72 He engages in similar activities at the Hooksett
Pool portion of the river, both upstream and downstream of the Station, roughly 20 to 30
times a year.73 He also “enjoy[s] seeing . . . fishermen [and] sportsmen” fishing in the
river and would be “crush[ed]” . . . if . . . the fish were affected” or “if there were no fish”
there.74
68 See id. (MacBride) at 42:22-43:14. 69 Id. (MacBride) at 42:14-21. 70 Id. (MacBride) at 46:12-15. 71 Trial Tr. 10.21.22 AM (Feigl) 5:5-8, 6:1-2. 72 Id. (Feigl) 6:8-12. 73 See id. (Feigl) at 8:5-9:4, 9:25-10:10, 25:15-20. 74 Id. (Feigl) at 22:1-6.
20 For Feigl, it is “important . . . that the river is clean and healthy[,]” given that he
has an interest in the river and surrounding activities, his daughter and he swim in the
river, his dog drinks from and plays in the river, and he consumes ducks that eat the fish
in the river.75 Feigl “ha[s] concerns about what the discharge from the [Station] may be
doing to the health and quality of the river[,]” and he “think[s]” that he “would feel better
about walking and canoeing and hunting along the river if [he] knew that the . . . [S]tation
were in full compliance” with the NPDES Permit.76
With this testimony, the plaintiffs have established that MacBride and Feigl
personally recreate in and around the river and/or pool and would enjoy these activities
more if they knew that the Station was not harming the health and natural state of the
water body. The witnesses’ concerns regarding the Station’s discharges are reasonable,
given their knowledge of the Station’s discharges, personal interests, and recreational
activities, and these concerns credibly limit their enjoyment and use of the river and pool.
This is sufficient to establish an injury in fact that is fairly traceable to the Station’s
discharges and redressable, at least in part, through the requested remedies, which seek to
limit the Station’s discharges and ensure compliance with the NPDES Permit. See, e.g.,
Laidlaw, 528 U.S. at 184 (finding “nothing improbable about the proposition that a
company’s continuous and pervasive illegal discharges of pollutants into a river would
cause nearby residents to curtail their recreational use of that waterway and would subject
75 See id. (Feigl) at 10:21-11:19. 76 Id. (Feigl) at 14:18-20, 15:20-22.
21 them to other economic and aesthetic harms” that constitute an injury in fact); Dubois,
102 F.3d at 1283 (finding, at the motion to dismiss stage, that a plaintiff had standing to
challenge the expansion of a skiing facility based on the allegations that his “family home
is located squarely within the geographical area allegedly directly affected by the
proposed project, [he] visits the area regularly, [he] drinks the water which will allegedly
be tainted by pollutants, and [he] will allegedly be deprived of his environmental,
aesthetic and scientific interests in ways directly tied to the project he challenges”).
B. Deference to EPA findings and determinations
Resolution of the plaintiffs’ claims turns on the meaning of, and the defendants’
record of compliance with, various provisions in the 1992 Permit. As previously noted,
the EPA is authorized under the CWA to develop NPDES permit provisions with the goal
of ensuring compliance with technology and water quality-based standards. In carrying
out this role, the EPA has assessed and opined on some of the same issues presently
before the court, as well as related matters, including the nature and extent of the
Station’s thermal discharge and its effect on the population and the conditions in the
Hooksett Pool.
The EPA’s analysis and conclusions on these matters form part of the trial record.
In particular, the parties entered into evidence and repeatedly referenced the EPA’s 2011
Determinations Document and 2020 Response to Comments, both of which the EPA
issues as part of its regulatory role under the CWA. See supra Section II.A. In order to
weigh this evidence, the court must determine the degree of deference owed to the EPA’s
findings and determinations. The parties agree that the agency’s conclusions are not
22 entitled to judicial deference under Chevron v. U.S.A. Inc. v. Natural Resources Defense
Council, Inc., 467 U.S. 837 (1984), and should instead be assessed under the standard set
forth in Skidmore v. Swift & Co., 323 U.S. 134 (1944).
These two theories of agency deference differ in application and effect. Chevron
deference generally applies “when it appears that Congress delegated authority to the
agency . . . to make rules carrying the force of law, and that the agency interpretation
claiming deference was promulgated in the exercise of that authority.” United States v.
Mead Corp., 533 U.S. 218, 226-27 (2001). Where applicable, Chevron requires courts to
“give effect to an agency’s regulation containing a reasonable interpretation of an
ambiguous statute.” Christensen v. Harris Cnty., 529 U.S. 576, 586-87 (2000).
In Skidmore, the Supreme Court held “that an agency’s interpretation may merit
some deference whatever its form, given the ‘specialized experience and broader
investigations and information’ available to the agency . . . , and given the value of
uniformity in its administrative and judicial understandings of what a national law
requires.” Mead, 533 U.S. at 234 (quoting Skidmore, 323 U.S. at 139-40); see also
Lovgren v. Locke, 701 F.3d 5, 30 (1st Cir. 2012) (“where an agency’s interpretation is
announced in a manner that lacks the force of law, Chevron deference may be
inappropriate[,] . . . [but] [s]uch interpretations are generally subject to review under
Skidmore . . . .” (internal citations omitted)). Relevant here, the argument for applying
the Skidmore standard is likely strengthened where the regulatory scheme at issue is
detailed. See Mead, 533 U.S. at 235 (“There is room at least to raise a Skidmore claim
23 here, where the regulatory scheme is highly detailed, and [the relevant agency] can bring
the benefit of specialized experience to bear on the subtle questions in this case”).
In determining the amount of deference owed to agency findings under the
Skidmore standard, courts consider a number of factors, including “the thoroughness
evident in [the agency’s] consideration, the validity of its reasoning, its consistency with
earlier and later pronouncements, and all those factors which give it power to persuade, if
lacking power to control.” Skidmore, 323 U.S. at 140. The First Circuit Court of
Appeals has held that the most “salient of the factors that inform an assessment of
persuasiveness” under Skidmore is “the validity of the agency’s reasoning.” Doe v.
Leavitt, 552 F.3d 75, 82 (1st Cir. 2009). “This inquiry does not focus on the [agency’s]
interpretation per se but, rather, on whether the agency has consulted appropriate sources,
employed sensible heuristic tools, and adequately substantiated its ultimate conclusion.”
Id.
Several of the Skidmore factors weigh in favor of deference to the EPA’s relevant
findings, discussed more fully below, across the board.
First, some degree of deference is proper in recognition of the EPA’s expertise in
promulgating NPDES permits and administering the CWA. Indeed, “issuing a permit and
determining its terms lie at the heart of EPA’s assigned task” under the CWA.
Conservation L. Found., Inc. v. Exxon Mobil Corp., 3 F.4th 61, 72 (1st Cir. 2021) (citing
33 U.S.C. § 1342); see also Arkansas v. Oklahoma, 503 U.S. 91, 105 (1992) (“Congress
has vested in the [EPA] Administrator broad discretion to establish conditions for NPDES
permits.”). It follows that the EPA’s reasonable interpretations of its own permits should
24 also be afforded deference. See Mead, 533 U.S. at 227-28 (“considerable weight should
be accorded to an executive department’s construction of a statutory scheme it is
entrusted to administer.”). Further, as described supra Section I.B, the EPA has been
issuing NPDES Permits for Merrimack Station since the 1970s. As part of this process,
the EPA has analyzed the Station’s operations and the Hooksett Pool environment for
decades, and engaged in data review and multiple notice-and-comment periods. This
decades-long engagement with the Station adds to the EPA’s expertise and reflects a level
of thoroughness that further warrants deference.
Finally, the EPA’s findings merit deference because of their detailed and technical
nature. For example, the EPAs determinations require analysis of data concerning water
temperature, river flow, and the characteristics of the pool’s fish population; studies
regarding different fish species’ tolerance and response to heat at various life stages; and
the physical dynamics of how heat pollutants disperse and travel in water.
All of these factors counsel the court against substituting its own judgment for the
reasoned determinations of the EPA regarding the meaning of the relevant Permit
provisions and the Station’s compliance with them. But the court’s Skidmore analysis
does not conclude here. The court also analyzes the EPA’s reasoning below, infra
Sections III.D-III.G, when reviewing the EPA’s individual findings regarding specific
Permit provisions. As discussed further below, the court finds that the EPA’s reasoning is
largely thorough, consistent, and well-supported, which further (and conclusively)
convinces this court that the EPA’s findings warrant significant deference. The court now
proceeds to the heart of the analysis—the merits of each of the plaintiffs’ claims.
25 C. Minimal contact with the shorelines (Count 3)
In Count 3, the plaintiffs allege continuing violations of Part I.A.1.g(c) of the 1992
Permit, which prohibits the Station’s “[c]ombined thermal plumes” from having more
than “minimal contact with the surrounding shorelines.” The court begins its analysis of
this Count with a few foundational findings of fact regarding this Permit provision and
the nature of the plaintiffs’ evidence of its violation.
First, the parties agree that the Permit does not define or otherwise provide
quantitative parameters for the minimal contact requirement. It is also undisputed that
the plaintiffs have not monitored the temperature at any point along the shorelines of the
Hooksett Pool.77 Instead, the plaintiffs’ evidence in support of this claim consists of a
model developed by engineer Matthew Hodge, to identify when the Station’s discharges
created an “extensive thermal plume”—that is, a plume with size and temperature
characteristics that he considers to be the “opposite” of “minimal contact with the
surrounding shorelines.”78 The court summarizes Hodge’s opinion below, and then
proceeds to assess a foundational flaw within it, which renders his opinion insufficient to
prove an ongoing violation of the minimal contact requirement by a preponderance of the
evidence.
77 Doc. no. 93 at AF ¶ 90. 78 Expert Report of Matthew Hodge (“Hodge Expert Report”) (Pls’ Ex. 16) at 5.
26 1. Hodge’s opinion
Hodge defined an extensive thermal plume by its temperature as well as its three-
dimensional shape. His extensive thermal plume has “a lateral extent (i.e., width across
the river), a vertical extent (i.e., depth into the water column), and a longitudinal extent
(i.e., distance downstream).”79 First, the plume must be at least 1° C (1.8° F) warmer
than the ambient river water, which is measured at Station N10, a monitoring station
approximately one mile upstream from the plant’s point of discharge.80 As noted above, a
difference in temperature is referred to throughout this Order in shorthand as a Delta-T.
Second, the extensive thermal plume must “contact[ ] the shoreline from bank to bank”
at least for the distance between Station S4 (again, located .4 miles downstream of the
discharge point) and a monitoring station 1.6 miles downstream from the discharge point,
referred to as S16.81 Third, the plume “extends below the surface to the bottom of the
river” at monitoring station A00, which is more than 2.5 miles downstream from the
discharge point; according to Hodge, this point is at the Hooksett Dam.82
In order to determine the presence of an extensive thermal plume in 2018 and
afterwards, the relevant period for this litigation, Hodge needed to identify the water
temperature at points that represent the boundaries of his extensive thermal plume—S4,
S16, and A00. Hodge used river flow data and temperature data from 2009 to develop a
79 Expert Rebuttal Report of Matthew Hodge (Pls.’ Ex. 17) at 20. 80 Hodge Expert Report (Pls’ Ex. 16) at 4. 81 Id. 82 Id.
27 linear regression model that can predict the downstream river temperatures during
“periods when there is no temperature monitoring” at those locations.83 The
“comprehensive” 2009 temperature dataset Hodge used for this model was collected at
six cross-sections of the river, including A00 and points near the monitoring stations
identified in the 1992 Permit—N10, S0, and S4. Nine probes were installed at each
cross-section except for A00; these probes were placed on the east, center, and west
portions, as well as the top, middle and bottom depths, of each cross-section.84
Hodge used his regression model to predict downstream river temperatures during
seven of the thirteen periods when Merrimack Station was operating from May through
October of 2018 and 2019.85 Hodge determined that these seven periods lent themselves
to such evaluation based on the nature of the Station’s operation and the reliability of the
surrounding data; in particular, he only considered periods in which the Station operated
for more than 37 hours, as “[s]table temperatures are present downstream of the discharge
during these periods of extended operation.”86 Of these seven periods, Hodge identified
four periods during which the Station’s discharge created an extensive thermal plume:
August 27-30, 2018; July 18-22, 2019; August 27-30, 2019; and September 2-4, 2019.87
83 Id. at 9, 26, 31, 42. 84 Id. at 19. See id. at 31; see also id. at 38 (identifying the predictor variables in the linear regression 85
model and listing the input and output values for 2018-19 linear regression). 86 Id. at 15-16, 31. 87 See id. at 38-39.
28 One conclusion that Hodge drew from his regression results was “that the thermal
plume is more likely to go bank to bank and violate the minimal contact requirement
when Unit 2 is in operation and flow is less than 2,000 [cubic feet per second].”88 He
reasoned in part that, of the seven periods he considered, an extensive thermal plume
arose in “[a]ll three of the periods when flow was below 2,000 cfs and Unit 2 was in
operation.”89 He further explained that only Unit 1 was operating when the fourth
extensive thermal plume arose, but this was also the period with “the second lowest
flow.”90
Building off of this conclusion, Hodge calculated the likelihood of an extensive
thermal plume occurring in the future, based on the probability of two independent events
taking place at the same time—low-flow conditions (which he defined as less than 2,000
cfs) and the operation of Unit 2. He assessed decades of flow data to determine that the
likelihood of low-flow conditions occurring from June through October (the “driest time
of the year”) is 51%.91 Hodge calculated that, if Unit 2 operates four or more times
during that same period, there is a greater than 90% chance that an extensive thermal
plume will develop, and the minimal contact condition will be violated, that year.92
Extrapolating from the fact that Unit 2 operated at least four times during those months in
88 Id. at 39. 89 Id. 90 Id. 91 Id. at 11-12, 44. 92 Id. at 44.
29 2016, 2018, and 2019, Hodge projected that “it is very likely that Merrimack Station will
cause extensive thermal plumes and violate the minimal contact condition . . . in 2020
and future years.”93
2. A core flaw in Hodge’s model
The defendants set forth evidence critiquing several aspects of Hodge’s concept of
an extensive thermal plume and his regression model. The challenges to Hodge’s
temperature criteria for the extensive thermal plume—the 1˚ C Delta-T threshold—are
particularly persuasive and dispositive, as explained further below.
To begin, in his report, Hodge provides some reasoning for his selection of a 1˚ C
Delta-T threshold. Hodge asserted that his “Delta-T threshold value is within the range
of values used by Merrimack Station consultants in the past and within the range of
values used by other states in US EPA Region 1.”94 He further explained:
My threshold value is higher than the value used by [Merrimack Station’s environmental consultant] Normandeau [Associates, Inc.] . . . when they identified “the potential area available to migrating salmon smolts” as the area that experiences a Delta-T of less than 0.5˚ C (0.9˚ F). . . . On the other hand, my threshold value is lower than the value used by [another Merrimack Station environmental consultant] when they defined a “significant” thermal plume as an increase above background of 2˚ C (3.6˚ F) or more. It is logical to conclude that the threshold value for the thermal plume should be less than the threshold value for a significant thermal plume. Similarly, of the six states within US EPA Region 1, three (Vermont, Connecticut, and Rhode Island) have water quality standards that include quantitative limits to the increase in water temperature relative to ambient temperatures. Vermont limits the increase in temperature for warm water fish habitat from 0.6˚ C (1˚ F) to 2.8˚ C (5˚ F) depending on the ambient temperature . . . Connecticut limits the increase in temperature to 2.2˚ C (4˚ F) and may be further limited to 0.8˚ C (1.5˚ F) depending on the classification of the
93 Id. 94 Id. at 18.
30 water body . . . . Rhode Island limits the increase in temperature for fresh waters to less than 2.2˚ C (4˚ F) . . . .95
This discussion raises more questions than it answers regarding Hodge’s Delta-T
selection. Hodge did not explain why it is reasonable to place his Delta-T threshold value
at a point between the other threshold values he cites, nor why he selected the precise
threshold of 1˚ C, from the range of values he described. Further, unlike the states of
Vermont and Connecticut, which adjusted their Delta-T values based on the
“classification of the water body” or the “ambient temperature,” Hodge did not assert that
he grounded his Delta-T value in biological criteria, thermal conditions, or other
surrounding circumstances. Hodge’s testimony at trial did not resolve this gap in his
reasoning. He testified that he selected the Delta-T threshold value “based on [his]
professional experience working on NPDES permitting of thermal discharges.”96
The importance of Hodge’s precise Delta-T selection became apparent during his
cross-examination, when he testified that he would have only found one extensive
thermal plume if he had selected a Delta-T greater than 1.2˚ C.97 Importantly, this higher
threshold value would pass muster under the general criteria that Hodge set forth in the
above excerpt from his report. Indeed, a Delta-T of 1.25˚ C (for example) would also
“fall within the range of values used by Merrimack Station consultants in the past and
95 Id. 96 Trial Tr. 10.18.22 AM (Hodge) at 14:12-17. The court cites to the transcripts from trial with the date; an “AM” or “PM” designation for morning and afternoon sessions, respectively; the witness’s last name; and the page and line numbers. 97 Id. (Hodge) at 100:1-12.
31 within the range of values used by other states in US EPA Region 1.”98 This means that
one of Hodge’s key findings—that four extensive thermal plumes arose in 2018 and
2019—is highly sensitive to small changes in his Delta-T threshold value, a number that
he selected for reasons that are not clear from the record.
The relative absence of support and reasoning for Hodge’s Delta-T selection also
taints the remainder of Hodge’s opinion, as it all flows from his definition of the
foundational concept of an extensive thermal plume. Indeed, each of Hodge’s ultimate
conclusions—regarding the occurrence of extensive thermal plumes in 2018 and 2019;
the relationship among low-flow conditions, the operation of Unit 2, and extensive
thermal plumes; and the probability of extensive thermal plumes occurring in the
future—all lack weight and meaning since his definition of the extensive thermal plume
is not sufficiently substantiated and credible. Given that their evidence supporting this
claim consists entirely of Hodge’s opinion, the plaintiffs have not sustained their burden
to prove a violation of the minimal contact requirement by a preponderance of the
evidence. The court accordingly rules in the defendants’ favor on Count 3.
D. Blocking the zone of fish passage (Count 1)
In Count 1, the plaintiffs allege violations of Part I.A.1.g(a) of the Permit, which
provides that “[t]he combined thermal plumes for the [S]tation shall . . . not block the
zone of fish passage.” In a previous Order on a summary judgment motion, the court
98 Hodge Expert Report (Pls.’ Ex 16) at 18.
32 determined that this provision bars the Station’s thermal plumes from blocking the
zone—that is, region or area—through which fish passage occurs.99
The court has not previously determined the meaning of “block” or the scope of
the “zone of fish passage,” however. At trial, the parties propounded differing
interpretations of these operative terms. They also presented evidence attempting to
prove Permit violations or compliance, consistent with their individual interpretations of
the provision.
In assessing this claim, the court begins with factual findings that provide context
for the remainder of the analysis. Then, the court summarizes each party’s position and
evidence before concluding that the plaintiffs have not proven an ongoing Permit
violation by a preponderance.
1. Foundational factual findings
To begin, this claim centers on two species of fish that migrate through the
Hooksett Pool—alewife and American shad.100 It is undisputed that these fish are
anadromous, meaning that they live in both freshwater and saltwater, at different points in
their life cycles.101 The fish spawn in freshwater such as the Hooksett Pool, remain there
for a period to grow and gain strength, and then migrate to the ocean during their first
99 Dec. 30, 2021 Summary Judgment Order (doc. no. 81) at 15. 100 Doc. no. 93 at AF ¶ 92. 101 Id. at AF ¶ 94.
33 year of life.102 They then return years later to spawn in the freshwater again.103 A series
of dams in the Merrimack River inhibit upstream migration of these fish at various
locations; thus, alewife and American shad are only able to migrate downstream through
the Hooksett Pool.104 The subject Permit provision accordingly concerns blockage of
these species’ downstream migration through the pool.
Both parties offered expert witness opinions from biologists to support their
positions. The defendants’ expert, Lawrence Barnthouse, Ph.D., has “been involved in
assessments of the impacts of power plants on fish populations since 1977.”105 The
plaintiffs’ expert, Adrian Jordaan, Ph.D., is an Associate Professor of Fish Population
Ecology and Conservation at the University of Massachusetts Amherst, with “past and
present research experience on temperature effects on fish, as well as movement
associated with fish passage structures, and impact of lost fish passage, on fish
species.”106
Both experts, as well as the EPA, agree that heat can have detrimental effects on
fish health, survival, and propagation. Indeed, Dr. Jordaan described temperature as a
“master variable” that “controls organization of aquatic system from cellular systems to
102 Id. at AF ¶ 95. 103 Id. 104 See id. at AF ¶¶ 96, 98. Expert Report of Larry Barnthouse (“Barnthouse Expert Report”) (Defs.’ Ex. 35) at 2; 105
Resume of Lawrence Barnthouse (Defs.’ Ex. 34) at 1. 106 Expert Report of Adrian Jordaan (“Jordaan Expert Report”) (Pls.’ Ex. 19) at 2.
34 ecosystem functioning.”107 The EPA further explained that “[w]ater temperature affects
virtually all biochemical, physiological, and life history activities of fishes[,] . . .
[including] metabolic rate, energy reserves, growth, reproduction, migration of fish, egg
maturation, incubation success, inter- and intraspecific competitive ability and resistance
to parasites, diseases, and pollutants.”108
The experts and the EPA refer to various thermal tolerance levels, or thermal
benchmarks, to describe how fish respond to different temperatures. Fish have optimal
temperature ranges, in which they function most efficiently.109 As temperatures rise
above these optimal ranges, they can reach avoidance levels, at which point fish respond
(as the name suggests) by avoiding the water, if they can. This behavior is an “adaptation
that allows fish to escape harmful temperatures.”110 Above avoidance levels are lethal
thermal limits, which can result in fish mortality. 111 In general, fish suffer worse effects
107 Id. at 4. 108 2011 Determinations Document (Pls.’ Ex. 3) at 62. 109 See Trial Tr. 12.2.22 AM (Barnthouse) at 39:24-40:2 (“Q. Now, each species of fish has evolved to have an optimum temperature at which they grow most effectively, correct? A. Correct.”), Jordaan Expert Report (Pls.’ Ex. 19) at 7 (fish “tend to be found within a range of temperatures that avoid both lower and upper thermal limits, a sweet spot where growth is maximized and the species are most likely to persist . . . .”). 110 Barnthouse Expert Report (Defs.’ Ex. 35) at 30; accord Jordaan Expert Report (Pls.’ Ex. 19) at 19, 22 (referencing fish “avoidance strategy” and noting that, where plumes reach alewife avoidance temperatures, this “would suggest [the alewife’s] avoidance of plumes.”). 111 Jordaan Expert Report (Pls.’ Ex. 19) (“Although fish (and other organisms) have tools to cope with a range of temperatures, each fish species has an upper thermal limit – a lethal temperature”); accord Trial Tr. 12.2.22 AM (Barnthouse) 40:23-41:9 (agreeing that above avoidance levels, fish “reach[] what is called the upper incipient lethal temperature . . . [,] the temperature at which for any given period of time half the fish in the population are expected to die,” and as temperatures rise beyond that, they would all die).
35 as temperatures approach and then exceed their thermal tolerance levels, and as they
experience longer periods of exposure to such temperatures.112
These thermal benchmarks vary across fish species and developmental stages.113
Particularly relevant here, the avoidance temperature for alewife is 28.9˚ C, and the
avoidance temperature for juvenile shad is a bit higher, at 29.4˚ C (according to the
plaintiffs)114 or 30˚ C (according to the defendants).115 The court adopts this avoidance
temperature for alewife because Dr. Barnthouse and the EPA rely on it,116 and Dr. Jordaan
agrees to ascribe to it, at least for his analysis in this case.117
112 See Trial Tr. 12.2.22 AM (Barnthouse) at 42:2-43:5 (agreeing, on cross-examination, that fish suffer increasing harm as temperatures rise from their optimal ranges and as they experience longer periods of exposure); 2020 Response to Comments (Defs.’ Ex. 9) at 68 (“Thermal stress that extends for prolonged periods during a season, particularly the critical summer season when many fish utilize thermal conditions to optimize their ability to grow in length and weight, and to mature, can cause adverse effects to fish populations sensitive to those conditions.”). 113 Jordaan Expert Report (Pls.’ Ex. 19) at 5; accord Barnthouse Expert Report (Defs.’ Ex. 35) at 24 (acknowledging that thermal tolerance levels vary by fish species and life stage, citing lower thresholds for larval fish, and noting that the EPA considered these variations when developing temperature limits for the 2020 NPDES Permit); 2020 Response to Comments (Defs.’ Ex. 9) at 74-85 (discussing the various thermal tolerance levels, including avoidance levels and lethal limits, for different fish species and life stages present in the Hooksett Pool). Pls.’ Post-Trial Findings of Fact (doc. no. 156) at ¶ 27t (citing EPA 2020 Response to 114
Comments (Defs.’ Ex. 9) at 77). 115 Barnthouse Expert Report (Defs.’ Ex. 35) at 6. 116 See Barnthouse Expert Report (Defs.’ Ex. 35) at 30 (“The avoidance temperature used by [the] EPA” in the 2011 Draft Permit and the 2020 Permit “(28.9°C) is consistent with the summer avoidance temperature derived from Wismer and Christie (1987), and is the most defensible of the available values.”). 117 Trial Tr. 10.19.22 AM (Jordaan) at 93:24-94:5 (expressing some hesitation about adopting a single number as an avoidance level, but agreeing that “the avoidance temperature of 28.9 is used repeatedly by the literature related to this case. So I will use that temperature and just say that at [higher plume] temperatures the alewife will no longer have access to the surface.”).
36 The court need not select between the parties’ definitions of juvenile shad
avoidance temperatures, given that its ruling remains the same under both alternatives.
This is because, as described more fully below, the lower avoidance threshold of alewife
is more central to the parties’ arguments and evidence.
2. The parties’ competing theories and evidence
Below, the court summarizes each party’s position, beginning with the plaintiffs.
The plaintiffs’ position. The plaintiffs assert, primarily through their expert
witness Dr. Jordaan, that the surface waters constitute the zone of passage for American
shad and alewife in the Hooksett Pool. Dr. Jordaan testified that laboratory research
indicates that alewife and shad “use the upper part of the water to move,” and they “move
quickly in groups to avoid being preyed upon.”118 He also testified that the fish migrate
at the surface of the water over the channel, or “the deepest part of the river,” which is
sometimes located in the center of the river, but also “meanders across the river” at
certain points.119
According to Dr. Jordaan, fish passage is blocked when the water temperature in
this specific zone reaches or exceeds avoidance levels. Dr. Jordaan testified that under
these circumstances, the fish are left with “a lot of bad options”—they may (1) stop upon
encountering the plume and potentially accumulate, leaving them more vulnerable to
predation; (2) “swim down or around [the plume] to near the benthic zone, which is the
118 Id. (Jordaan) at 62:5-16. 119 Trial Tr. 10.19.22 PM (Jordaan) at 94:2-8; Trial Tr. 10.20.22 AM (Jordaan) at 87:1-17.
37 bottom of the river . . . [,] an area where there are lots of predators[;]” (3) “turn around
and swim back upstream”; or (4) swim into the heated water “against their best
judgment.”120 On top of these specific scenarios, Dr. Jordaan also opined that elevated
temperatures generally increase predation threats by taxing the metabolic efficiency of
fish. As a result of this biological response, Dr. Jordaan asserts, predators consume more
food, and prey (such as alewife) have less energy to devote to predator avoidance.121
In Dr. Jordaan’s opinion, each of the “bad options” he described block alewife and
shad from migrating, “either because of mortality, predation by the suite of species that
will eat them, or because they avoided the temperatures altogether and stopped their
movements downstream.”122 In other words, under the plaintiffs’ theory, fish passage is
blocked when the Station’s surface-oriented thermal plume reaches avoidance levels,
regardless of whether fish swim through the plume or avoid it. Dr. Jordaan testified that
this blocking effect occurs once the duration of the thermal plume “start[s] crossing into
minutes . . . [or] tens of minutes.”123
As evidence of past and ongoing violations, Dr. Jordaan opined that “[t]he zone of
fish passage has been blocked by the bank-to-bank and top-to-bottom plumes on the dates
120 Trial Tr. 10.19.22 AM (Jordaan) at 94:12-95:6, 97:10. 121 See Jordaan Expert Report (Pls.’ Ex. 19) at 19 (noting that “alewives are bait fish that experience high mortality” and discussing the additional predation risks that alewife and shad face in warm water due to higher metabolic requirements). 122 Trial Tr. 10.19.22 AM (Jordaan) at 97:14-17. 123 Trial Tr. 10.25.22 AM (Jordaan) at 17:15-18:2
38 identified by Hodge . . . as having extensive thermal plumes.”124 As discussed supra
Section III.C.1, Hodge identified extensive thermal plumes during four periods—August
27-30, 2018; July 18-22, 2019; August 27-30, 2019; and September 2-7 2019. According
to Dr. Jordaan, these extensive thermal plumes overlapped with the period of
outmigration for juvenile alewife and American shad, which he defined as mid-June
through October.125
In an additional attempt to prove blockage, the plaintiffs also pointed to 15-minute
temperature data gathered by the defendants at S4 in July and August of 2018, 2019, and
2022. The plaintiffs identified that at certain times during those months, temperatures at
S4 consistently exceeded alewife avoidance levels for hours or days at a stretch.126 The
plaintiffs also uncovered two periods between July 19 and August 10, 2022 when the
ambient temperatures at N10 approached or exceeded alewife avoidance levels, and the
124 Jordaan Expert Report (Pls.’ Ex. 19) at 19. 125 Trial Tr. 10.19.22 AM (Jordaan) at 60:4-11. 126 See, e,g., Pls.’ Post-trial Findings of Fact (doc. no. 156) at ¶¶ 38k, 38m, 38n, 38v. In a post- trial submission, the plaintiffs also presented calculations of average temperatures during selected portions of 2018, 2019, and 2022, which they did not present at trial. More specifically, the plaintiffs calculated periods when average temperatures at Station S4 exceeded 28.9˚ C for a day or longer. See, e.g., id. at ¶¶ 38f, 38g, 38l. The selected periods began and ended on seemingly arbitrary times and dates. For instance, the plaintiffs calculated the average temperature at S4 from July 2, 2018 at 3:30 p.m. through July 6, 2018 at 6:30 a.m. Id. at ¶ 38f. The plaintiffs did not explain the rationale behind the start and stop times that they selected, or how sensitive their results were to those selections. The defendants appropriately assert in a post-trial brief that these calculations should not be considered because they were not entered into evidence or subject to cross-examination at trial. Doc. no. 159 at 12-13. The court agrees and accordingly does not consider the plaintiffs’ averaging calculations which were not presented at trial.
39 temperatures at S0 and S4 were higher than that.127 When questioned at trial about these
periods, Dr. Barnthouse agreed with the plaintiffs’ understanding of the temperature
readings during the July 19-August 10 period.128 He also agreed that these thermal
conditions indicated that for about five days during each of those months, alewife would
have experienced unsuitable temperatures if traveling through, under, or around the
plume, as all of these areas would have been at or above avoidance levels when
temperatures at N10 were that high.129
The defendants’ position. The defendants ascribe to a broader and more flexible
interpretation of the zone of fish passage. As a general matter, Dr. Barnthouse agreed that
the surface waters over the channel are a common zone for passage. He testified that
migrating alewife and shad are “not always, but often” located at the surface of the river
during migration,130 and that “their preferred route” is at the surface over the channel.131
But the defendants do not consider the surface water to be the only zone of fish passage.
127 See Pls. Ex. 61 (15-minute temperature data in 2022); Pls.’ Ex. 85 (line graph representing the 2022 data and reflecting the temperature exceedances in July and August of 2022). 128 Trial Tr. 12.2.22 AM (Barnthouse) at 72:3-4, 72:16-73:16, 74:20-24. When questioning Dr. Barnthouse, the plaintiffs showed him graphs depicting the temperatures during certain periods. Plaintiffs’ counsel had not previously provided those graphs to defense counsel. The plaintiffs sought to admit the graphs into evidence as demonstratives of raw temperature data listed in Plaintiffs’ Exhibit 61. The court permitted counsel to use the graphs when questioning Dr. Barnthouse but did not admit the graphs into evidence. Id. at 57:9-58:8. In rendering its decision, the court relied on the graphs only inasmuch as they were used to question Dr. Barnthouse. 129 Id. (Barnthouse) at 73:18-74:19. 130 Trial Tr. 10.25.22 AM (Barnthouse) at 94:21-25. 131 Trial Tr. 10.25.22 PM (Barnthouse) at 23:4-8.
40 They contend that fish can also pass below or around the Station’s surface-oriented
thermal plume when it is sufficiently limited in size, temperature, and/or duration.
The defendants rely on several EPA findings to support their position. First, the
record shows that the EPA has acknowledged for years that the size, temperature,
duration, and configuration of the Station’s thermal plumes are relevant when evaluating
the plumes’ effect on fish passage. Indeed, the EPA has repeatedly noted that, if the
plume is sufficiently limited under these parameters, the water under or around the
Station’s thermal plume can provide a suitable area for fish passage. The EPA has also
found that such conditions are likely present when the Station operates as a peaking
facility. The court describes these findings in more detail below.
An earlier pronouncement of the possibility of fish passage under or around a
limited thermal plume in the Hooksett Pool appears in a 1991 memorandum written by an
EPA Senior Permit Engineer regarding the Station. The engineer wrote that “[w]ith the
arrival of the anadromous fish in a couple of years” the agency needed more “information
on the correlation” between the Station’s operations and the “in-stream thermal plume
configuration and the concomitant fish blockage/passage . . . .”132 The engineer added
that zones of fish passage may exist “under or around the [Station’s] thermal plume,” but
it was “not possible to determine” the existence of such passage ways at that time
because “the regulatory agencies[ ] lack[ed] data that would define the plume
132 Defs.’ Ex. 2 at 3.
41 configuration (temperature distribution) in several vertical river cross-sections (fish
passage ways).”133
Years later, in the 2020 Response to Comments, the EPA was able to test this
theory of fish passage with the benefit of a “three-dimensional, hydrothermal computer
model developed” by environmental consultants in 2010 “to predict the behavior of the
thermal plume at baseload operations under ‘average’ and ‘extreme’ conditions based on
[river] flow and upstream river temperatures.”134 Upon reviewing the model’s
predictions as well as temperature data, the EPA found that “an adequate zone of fish
passage is likely available” under or around the Station’s thermal plumes during the
periods when alewife and American shad are migrating. Specifically, the EPA determined
that
[t]emperature data and thermal modeling indicate that in spring, when certain anadromous species, such as American shad, may be moving past the Facility, low ambient temperatures and higher river flows combine to ensure that an adequate zone of passage is likely available beneath the surface-oriented plume and on the eastern side of the river. Similarly, an adequate zone of passage exists under most conditions in fall when juvenile alewives may be migrating past the Facility. Under current operations (i.e., more like a peaking plant), the Facility operates at low capacity during spring and fall. However, neither the thermal modeling nor the actual temperature data clearly demonstrate that an adequate zone of passage is available under conditions when the Facility is operating at full capacity and ambient temperatures are highest (e.g., summer), particularly during years with low river flow. ...
Since 2012, however, the Facility operates infrequently in July and August and, when it does operate, it is typically for short durations (one week or less). If the Facility operates at high capacity during July and August in years with low flow
133 Id. 134 2020 Response to Comments (Defs.’ Ex. 9) at 109.
42 and high ambient temperatures, resident fish may avoid moving past the Facility due to temperatures in the thermal plume. However, the Final Permit’s operational limits will ensure that the duration of the event is limited such that protection and propagation of the BIP is assured.135
The EPA also reviewed daily temperature data under peaking operations during the
migration period for alewife and shad. As part of this analysis, the EPA identified a
shorter, and later, migration period than Dr. Jordaan did. As noted above, Dr. Jordaan
opined that these fish migrate downstream from mid-June through October. The EPA, on
the other hand, maintained that alewife and shad in the Merrimack River typically
migrate from late August through October.136
The EPA did find that temperatures exceeded avoidance levels at Station S4
occasionally under peaking operations during the migration period, but these exceedances
were sufficiently limited to permit fish passage, as well. Specifically, the EPA identified
that mean and maximum daily temperatures at Stations S4 and S0 occasionally exceeded
28.9˚ C in August and September 2016, when the “capacity of the Station was, on
average, 9%,” but those “[e]xcursions of protective temperatures for juvenile alewives
[we]re limited in duration and extent.”137 According to the EPA, “[t]his data suggests
that, under current [peaking] operations, the thermal plume is unlikely to impact juvenile
135 Id. at 111. 136 Id. at 75. 137 Id. at 77.
43 alewives because juveniles can avoid the plume and will not be excluded from potentially
suitable habitat for extended periods of time.”138
As for juvenile shad, the EPA considered mean and maximum daily temperature at
Station S4 in 2018, “which is representative of average operation in August and
September,” and found that temperatures at S4 “rarely reached or exceeded protective
temperatures for juvenile American shad[,] and exceedances that did occur were limited
in duration.”139 The EPA subsequently concluded that “the thermal plume under current
[peaking] operations is unlikely to impact juvenile American shad because juveniles are
likely to avoid the plume for the limited period when it is present downstream of the
discharge and will not be excluded from potentially suitable habitat for extended periods
of time.”140 The EPA added that “American shad juveniles are mobile, and will likely
avoid extreme temperatures that may occur in the relatively limited segment from S0 to
S4.”141
Dr. Barnthouse agreed with the EPA’s definition of the migration period, as well as
its conclusions regarding the availability of fish passageways under or around the thermal
plume during peaking operations.142 Dr. Barnthouse also offered quantitative evidence in
support of the EPA’s latter opinion. This evidence focused on the four periods when
138 Id. 139 Id. at 78. 140 Id. 141 Id. 142 See Trial Tr. 10.25.22 AM (Barnthouse) at 20:12-21:22, 35:3-5.
44 Hodge identified an extensive thermal plume—periods during which Dr. Jordaan also
believed that fish passage was blocked. For each of these periods, Dr. Barnthouse used
Hodge’s linear regression model to calculate the average and maximum river
temperatures at nine points on the transect, or cross-section, where the S4 temperature
probe is placed—on the center, east, and west sides of the transect, and at the top, middle,
and bottom depths. In other words, he calculated the average and maximum temperature
on either side and below the S4 probe during each of the extensive thermal plume
periods.
Dr. Barnthouse found that, for every period modeled, the average temperature on
the east side of the S4 probe was always lower than avoidance levels, and “the maximum
east side surface temperature at Station S4 exceeded the [a]lewife avoidance temperature
only during [one] period[,] July 18-22, 2019.”143 Finally, Dr. Barnthouse determined that,
during each period modeled, the average temperature at the middle and bottom depths of
the S4 transect were always below avoidance temperatures.144 With this evidence, Dr.
Barnthouse concluded that, during each extensive plume, “at the surface of the river, a
migration corridor for [a]lewife and shad would have been available on the east side of
the river except on rare occasions,” and alewife and shad could migrate in the middle or
bottom of the river “unimpeded” by unfavorable temperatures.145
143 Barnthouse Expert Report (Defs.’ Ex. 35) at 9 (emphasis added). 144 Id. 145 Id.
45 Weighing the evidence. Having summarized the parties’ positions, the court now
considers which is more persuasive. The court begins with the parties’ competing
interpretations of the meaning of the subject Permit provision, as this will determine what
activity is violative of the Permit. When interpreting the meaning of NPDES permits,
contract interpretation principles apply. Piney Run Pres. Ass’n v. Cty. Comm’rs of
Carroll Cty., 268 F.3d 255, 269 (4th Cir. 2001). Accordingly, the court must “first
determine whether [the provision] is ambiguous.” Id. at 269-70. “Contract language is
usually considered ambiguous . . . where the phraseology can support reasonable
differences of opinion as to the meaning of the words employed and obligations
undertaken.” Fashion House, Inc. v. K mart Corp., 892 F.2d 1076, 1083 (1st Cir. 1989)
The court considers the subject Permit provision ambiguous for at least three
reasons. First, the Permit does not define the phrase “the zone of fish passage.” Further,
the term “block” has a relatively broad meaning, including “[t]o obstruct or close with
obstacles (a passage),”146 or to “make unsuitable for passage.”147 Finally, the court finds
that both parties’ interpretations of these terms are reasonable.
Indeed, the plaintiffs’ narrow interpretation of the provision is based on Dr.
Jordaan’s credible expert opinion. He grounded his opinion in theories about fish biology
that are both logical and not seriously refuted by the defendants—essentially, in
146 Oxford English Dictionary, available at https://www.oed.com/dictionary/block_v1?tab=meaning_and_use#18033746. Merriam-Webster Dictionary, available at https://www.merriam- 147
webster.com/dictionary/block.
46 attempting to avoid temperatures that are unfavorable, fish may stop migrating or face a
delay or alteration in their migration route which could increase predation threats by
slowing them down, forcing them to swim in areas where predators are more prevalent,
and/or taxing their metabolism and ability to avoid predators. Dr. Jordaan’s conclusion
that these outcomes constitute blockage of fish passage is sound.
Meanwhile, the defendants source their interpretation of the Permit provision from
the EPA itself—the permitting agency. The EPA’s conclusion that fish passage is not
blocked when fish are able to swim under or around the Station’s surface-oriented plume
is also rational and consistent with the experts’ shared opinion that fish can respond to
unfavorable temperatures through avoidance tactics. The EPA’s opinion is also
persuasive because it has been consistent over time, and it relies on relevant data and
evidence. Specifically, the EPA acknowledged the possibility of fish passage below and
around the Station’s thermal plumes as early as 1991, and it confirmed the theory in
2020, using thermal modeling and temperature data reflecting the Station’s more recent
peaking operations.
Where, as here, a NPDES Permit provision is ambiguous, the court “must turn to
extrinsic evidence to determine the intent of the permitting authority.” Piney Run, 268
F.3d at 270. Naturally, when engaging in this inquiry, courts “give significant weight to
any extrinsic evidence that evinces the permitting authority’s interpretation of the
relevant permit.” Nat. Res. Def. Council, Inc. v. Cnty. of Los Angeles, 725 F.3d 1194,
1207 (9th Cir. 2013). Consistent with these principles, the court places significant weight
on the EPA’s interpretation of the Permit provision. Such deference is also warranted
47 under the Skidmore standard, due to the persuasiveness of the EPA’s interpretation, as
discussed in the previous paragraph, and for the reasons stated supra Section III.B.
The court now weighs the plaintiffs’ evidence against the EPA’s definition of the
Permit provision. In other words, the relevant inquiry at this stage is whether the
plaintiffs have proven, by a preponderance, that the Station’s thermal discharges are
likely to block the zone of fish passage by creating thermal conditions in, around, and
under the thermal plume that are inhospitable to the migrating juvenile alewife and shad.
First, the court cannot find a Permit violation based on the plaintiffs’ evidence of
exceedances of thermal tolerance limits at S4 because the record indicates that these
temperature readings are not informative of the thermal conditions beyond the probe
itself. As previously noted, supra Section I.C, the S4 temperature probe captures surface
water temperatures about 2,000 feet downstream of the of the Station’s discharge point.
When asked during cross-examination, Dr. Jordaan agreed that the data gathered at the S4
probe did not provide him with information about the temperature of the water beyond
the specifical location of the probe.148 He further testified, without further elaboration,
that he “assume[d] . . . , based on all the information that [he] viewed,” that the S4
probe’s monitoring area “covers enough space to create a blockage of the zone of fish
passage.”149
148 Trial Tr. 10.19.22 PM (Jordaan) at 93:7-9. 149 Id. (Jordaan) at 93:14-22.
48 The plaintiffs did not attempt to strengthen this limited testimony with evidence
suggesting that the S4 probe’s monitoring area extends a meaningful distance across or
beneath the pool’s surface. Instead, the plaintiffs pointed to excerpts of the 2020
Response to Comments in which the EPA discussed the temperatures at the S4 probe as
an indicator of whether or not the pool’s thermal conditions were protective of migrating
fish. This argument misrepresents the EPA’s statements.
While the EPA did assert that repeated, high temperatures at S4 were “consistent”
with the conclusion that the river conditions were not protective of migrating fish, it
followed that assertion by “acknowledg[ing]” that fish “could potentially avoid higher
temperatures [at S4] if the plume were sufficiently limited to allow areas of passage.”150
Further, as discussed above, the EPA repeatedly stated that fish passage was possible
when S4 temperatures exceeded avoidance levels for limited durations. Based on the
evidence before it, the court cannot conclude that the S4 temperatures reflect the thermal
conditions under or around the Station’s thermal plume and are thus indicative of the
availability of fish passage through those areas.
The plaintiffs did provide evidence of two distinct week-long periods between July
19 and August 10, 2022, however, when S4 temperatures exceeded avoidance levels, and
the cooler water was likely not available under or around the plume because ambient
temperatures also reached or exceeded avoidance levels. This is compelling evidence
that fish passage ways were not available under or around the Station’s thermal plume
150 See, e.g., 2020 Response to Comments (Defs.’ Ex. 9) at 76.
49 during those periods. This is not adequate evidence of a Permit violation, however, if it
occurred outside of the alewife and shad outmigration period. Thus, in order to
determine the weight of this evidence, the court must first decide whether to credit the
EPA’s definition of the outmigration period (late August through October) over Dr.
Jordaan’s definition (mid-June through October).
In substantiating its definition of the outmigration period, the EPA acknowledged
that juvenile alewife migrate “between June and November” in “most Atlantic coast
populations.”151 The EPA found that the outmigration period in Merrimack River was
later, however, based on data that was largely drawn from the Hooksett Pool—a United
States Fish & Wildlife Service study; “historical fisheries data” that “suggest[ed] that
young-of-year and adult alewives generally are not common in Hooksett Pool except during
periods of out-migration, which typically occur in September or October”; and fish sampling
data collected by Normandeau in 2006, which demonstrated that juvenile alewife were
present in the pool in late August.152 Dr. Jordaan, on the other hand, cited a few scientific
studies to support his assessment of the alewife outmigration period, two of which
pertained to trends in water bodies in Connecticut and Massachusetts.153 The court finds
the EPA’s reasoning more convincing, as it is focused on the Hooksett Pool, instead of
other water bodies. The court also credits the EPA’s position due to its expertise,
consistent with Skidmore. Thus, the plaintiffs’ evidence of heightened temperatures in
151 Id. at 75. 152 Id.; EPA 2011 Determinations Document (Pls.’ Ex. 3) at 121-22, 239-40. 153 Rebuttal Report of Adrian Jordaan (“Jordaan Rebuttal Report”) (Pls.’ Ex. 20) at 19.
50 the July 19-August 10, 2022 period does not effectively prove a Permit violation because
this period likely did not overlap with the outmigration of alewife and shad.
Finally, the court is not persuaded by Dr. Jordaan’s opinion that fish passage is
blocked when the Station’s discharges create what Hodge considers an extensive thermal
plume, for at least two reasons. First, as discussed supra Section III.C, the court does not
find Hodge’s concept of an extensive thermal plume to be sufficiently credible to prove a
Permit violation. Second, Dr. Jordan’s conclusion was at least partially disproven by Dr.
Barnthouse’s determinations that whenever an extensive plume was present according to
Hodge, the water below or around the S4 probe was almost always cooler and hospitable
to fish passage. Critically, Dr. Barnthouse based this conclusion on the results of a
regression model developed by Hodge, the plaintiffs’ own expert. Accordingly, the
plaintiffs do not meaningfully challenge Dr. Barnthouse’s approach for estimating the
temperatures surrounding the S4 probe.
The court recognizes that Hodge’s model may present flaws that weigh against the
reliability of the regression results. Dr. Barnthouse calculations nevertheless provide
some evidence that further weakens Dr. Jordaan’s already unadorned and insufficiently
persuasive opinion on this matter. The court concludes that the purported past or future
presence of extensive thermal plumes does not meaningfully support a finding of ongoing
violations of the Permit as alleged in Count 1.154
154 Dr. Jordaan provided one more opinion regarding fish blockage and the impact of temperature on the fish in the pool, but the court finds it wholly unpersuasive. Nevertheless, the court takes this opportunity to briefly describe the opinion and its pitfalls. Dr. Jordaan selected four periods “with adequate data . . . to illustrate the consequences of the thermal plume.” Jordaan Expert 51 Conclusion. In sum, the plaintiffs have not provided evidence that persuades the
court, by a preponderance, that the Station is likely to violate the Permit by blocking the
zone of fish passage under the EPA’s definition of the subject Permit provision. The
plaintiffs accordingly do not prevail on Count 1.
E. Balanced indigenous population (Count 2)
In Count 2, the plaintiffs allege continuing violations of Part I.A.1.g(b) of the
Permit, which prohibits the Station from “chang[ing] the balanced indigenous population
of the receiving water.” The parties agree that the phrase “balanced indigenous
population” (“BIP”) is defined in an EPA regulation as follows:
The term balanced, indigenous community is synonymous with the term balanced, indigenous population in the [CWA] and means a biotic community typically characterized by diversity, the capacity to sustain itself through cyclic seasonal changes, presence of necessary food chain species and by a lack of domination by pollution tolerant species. Such a community may include historically non-native
Report (Pls.’ Ex. 19) at 14. These periods spanned from June through September 2018 and July through September 2019. Id. For each multi-day period, Dr. Jordaan identified the maximum Delta-T value at A00 and the maximum temperature reached at N10. He then summed these values; according to Dr. Jordaan, the resulting number demonstrated the “impact [that] would have been experienced by every fish within the downstream section of the Hooksett Pool.” Id. For each of the four periods, Dr. Jordaan found that the sum of these values reached the lethal limit for adult and/or juvenile alewife. See id. at 15-19. Dr. Jordaan stated that “there’s a lot of opportunity for the two temperatures to converge, [though] perhaps not precisely.” Trial Tr. 10.19.22 PM (Jordaan) at 97:2-5. He did not credibly or definitively assert that the maximum N10 value and the maximum Delta-T value at A00 occurred at the same time, however, nor did he suggest the frequency or duration of such convergence(s). Id. (Jordaan) at 97:6-9 (“Q. Well, without knowing when A00 was at its max during this period, you don't know when [the maximum N10 and A00] temperatures may match up, if ever; is that right? A. That is true.”). Furthermore, Dr. Jordaan did not provide clarity on the purpose of his calculation at trial; instead he testified that this exercise “represent[ed] a worst-case scenario based on some assumptions.” Id. at 96:15-20. Thus, it is not clear how, if at all, the sum of these values is a realistic representation of the thermal conditions in the Hooksett Pool at any time during the selected periods. The court accordingly discounts this portion of Dr. Jordaan’s opinion.
52 species introduced in connection with a program of wildlife management and species whose presence or abundance results from substantial, irreversible environmental modifications. Normally, however, such a community will not include species whose presence or abundance is attributable to the introduction of pollutants that will be eliminated by compliance by all sources with section 301(b)(2) of the Act; and may not include species whose presence or abundance is attributable to alternative effluent limitations imposed pursuant to section 316(a).
40 C.F.R. 125.71(c).155 The court applies this agreed-upon definition when assessing this
claim.
The EPA discussed the impact of the Station’s discharges on the Hooksett Pool
BIP in the 2011 Determinations Document and the 2020 Response to Comments. In
2011, the EPA determined that the Station’s discharges caused “appreciable harm” to the
BIP. In 2020, however, the EPA observed that the status of the BIP had improved since
the Station reduced its operations and began functioning as a peaking facility. The EPA
concluded in 2020 that the Station’s discharges were protective of the BIP, and the 2020
Permit requirements would ensure continued protection of the BIP. The parties focused
heavily on the EPA’s analysis and conclusions on this matter during trial—specifically,
the plaintiffs relied on the EPA’s 2011 findings, and the defendants relied on the EPA’s
2020 findings. The plaintiffs also set forth a range of evidence that they argue indicated
that the Station continues to harm the pool’s BIP, while the defendants set forth evidence
that the Station has complied with the 2020 Permit, and thus continues to protect the BIP.
155 The parties agree that the Permit does not define the phrase “balanced indigenous population,” but the phrase “balanced indigenous community” is defined in the cited EPA regulation. See doc. no. 93 at AF ¶¶ 19-20.
53 The EPA’s conclusion in 2020, if credited, weighs heavily against the likelihood of
ongoing violations of this Permit provision. Accordingly, the fate of this claim largely
turns on the weight of the EPA’s determination in 2020, as compared to evidence that
(according to the plaintiffs) contradicts and undermines that determination.
The court begins by summarizing the EPA’s analysis and conclusions regarding the
status of the BIP in 2011 and 2020 and assessing the weight of these agency findings.
Then, the court describes and evaluates the strength of the defendants’ evidence of the
Station’s compliance with the 2020 Permit, and the plaintiffs’ evidence of harm to the
BIP. Based on a comparison of the competing evidence, the court finally concludes that
the plaintiffs have not sustained their burden to prove ongoing violations of this Permit
provision.
1. The EPA’s assessment of the status of the BIP
The EPA’s 2011 findings. In 2011, the EPA found that “compelling evidence
[shows] that [the Station’s] thermal discharge, possibly in combination with other impacts
on the affected species, has appreciably harmed the balanced, indigenous community in
Hooksett Pool.”156 The EPA largely relied on two categories of evidence to draw this
conclusion—data from sampling activities conducted in the Hooksett Pool over time, and
two decades of daily temperature data gathered from the monitoring stations at N10, S0,
and S4.
156 2011 Determinations Document (Pls.’ Ex. 3) at 149.
54 The EPA began with the premise “that the relevant balanced, indigenous
community is comprised of all species that existed in Hooksett Pool immediately prior to
the start-up of Unit 1 [of Merrimack Station], in 1960.”157 “[C]omprehensive biological
sampling” in the pool was first conducted in 1967, however—seven years after Unit 1
began operating and one year before the start-up of Unit 2.158 The EPA accordingly
decided that “the resident biotic community identified during sampling conducted from
1967 to 1969 [was the] best represent[ation] [of] the [pool’s] balanced, indigenous
community . . . because the 1967-1969 data [was] the earliest data available, and because
the volume of heated cooling water discharged into Hooksett Pool more than tripled in
1968 after Unit 2 came on line.”159
When the EPA made its 2011 determinations, it had access to fish sampling data
that was collected intermittently from the late 1960s and early 1970s through 2005. The
EPA compared the newest and oldest data, and it found “several conspicuous pieces of
evidence” demonstrating “appreciable harm” to the pool’s fish community over this
period.160 For example, the EPA found a 94 percent decline in the “[a]bundance for all
species combined that comprised Hooksett Pool’s balanced, indigenous community”
between the 1960s and the 2000s; “[a] calculated Bray-Curtis Percent Similarity Index161
157 Id. at 64. 158 Id. 159 Id. 160 Id. at 149. 161 In the 2011 Determinations Document, the EPA described, and credited, PSNH’s explanation of the Bray-Curtis index. This index “computes percent similarity among the fish taxa common 55 of 23.2 percent when comparing [the] Hooksett Pool fish community of the 1970s with
that of the 2000s,” meaning that “the fish communities of the 1970s and 2000s [were]
dissimilar by 72.8 percent”; and a shift from a mix of warm and coolwater fish in the
1960s and early 1970s “to a community dominated by thermally tolerant species . . . in
the 1990s and 2000s.”162 The EPA also noted a decline in the population abundance of
three “residential, indigenous species”—pumpkinseed, white sucker, and yellow perch.163
According to the EPA, pumpkinseed was “the most abundant fish species in 1967” but
had “virtually disappeared” by the mid-2000s;164 white sucker abundance fell from 18.2
percent in the 1970s to 2.1 percent in the 2000s;165 and yellow perch “abundance in
Hooksett Pool significantly declined between 1967 and 2005.”166
After identifying this shift in the pool population, the EPA reviewed thermal
studies analyzing the configuration of the Station’s thermal plumes, as well as
temperature data collected at N10, S0, and S4 from 1984 through 2004, to confirm
whether the population changes could be attributed to the Station’s discharges, as
opposed to the other “natural and anthropogenic stressors” that can cause “appreciabl[e]
in two sets of survey data . . . .” Id. at 104. “The closer the Bray-Curtis value is to 100%, the more similar the two communities are.” Id. at 105. 162 Id. at 150. 163 Id. at 66. 164 Id. at 133, 150. 165 Id. at 145. 166 Id. at 150.
56 harm.”167 Based on the thermal studies, the EPA concluded that the “capacity of the
[Station’s] thermal discharge to adversely impact the balanced, indigenous community of
Hooksett Pool is significant.”168 Specifically, the EPA noted that “[t]hermal studies
conducted by Merrimack Station since the 1960s” established that the “plume’s
configuration is affected by river flow.”169 “During summer low-flow conditions,
Merrimack Station’s thermal plume can extend” across “approximately 50 percent of the
surface area of Hooksett Pool.”170 Furthermore, “most, if not all, of the shallower areas
along the shorelines”—which are “widely recognized as important habitat for juvenile
fish”—“can be affected by the thermal plume downstream from the discharge.”171
Finally, the EPA compared daily temperature data against the thermal tolerance
levels of Hooksett Pool fish species at various times of year and life stages, as reported in
scientific literature. The EPA observed that the temperatures in portions of the pool
repeatedly exceeded certain fish species’ tolerance levels when those fish were present,
further supporting its conclusion that the Station’s discharges harmed the pool’s BIP. For
example, the EPA found that “American shad larvae drifting past Station [S0] as early as
May 26 could be exposed to temperatures” that can be lethal,172 and “ yellow perch larvae
167 Id. at 151. 168 Id. 169 Id. at 71-72. 170 Id. at 151. 171 Id. at 72, 152. 172 Id. at 125.
57 were [likely] exposed to potentially lethal temperatures within Merrimack Station’s
thermal plume” when they were likely present around May and June of some years.173
The EPA found further evidence of unfavorable thermal conditions prior to 2011 in “daily
temperature data from 2004 through 2011[,]” which “indicate[d] that the mean and
maximum S0 and S4 temperatures steadily exceed [the avoidance temperature for yellow
perch juvenile and adults] between June 15 and September 10 in most years.”174
The EPA’s 2020 findings. As previously discussed, the EPA did not issue the
2011 Draft Permit, and instead reopened the public comment period and drafted a new
Permit, in part to address the Station’s transition in 2012 from a baseload to a peaking
facility. As part of this process, the EPA re-assessed the effect of the Station’s thermal
discharges on the pool’s BIP and reported its findings in the 2020 Response to
Comments.
Once again, the EPA relied on fish sampling and temperature data for its analysis.
This time, the EPA had access to more recent, daily temperature data from 2004 through
2019, as well as fish sampling data collected by Normandeau each year from 2010 to
2013—a period that coincided with the Station’s transition from a baseload to a peaking
facility.175 The new fisheries data “provide[d] the first ever comparisons between the
Hooksett Pool fish community and that of the [upstream] Garvins Pool,” two “adjacent”
and “similar,” though “not . . . identical[,] waterbodies,” the latter of which does not
173 Id. at 137-38. 174 2020 Response to Comments (Defs.’ Ex. 9) at 80. 175 Id. at 97, 216.
58 receive thermal discharge from the Station.176 With this additional information, the EPA
had two “acceptable representation[s] of the proper [balanced, indigenous population]”—
the Hooksett Pool fish community of the 1970s as well as the Garvins Pool fish
community.177
According to the EPA, the new “fish community” data did not change its prior
“conclusions regarding the status of the BIP as of 2005,” but the new data did “suggest
[that] conditions [had] improved in Hooksett Pool.”178 For example, the EPA found that
the “proportion of coolwater to warmwater species in Hooksett Pool [ ] increased” from
the 1970s to the 2010-13 period, and “the balance of warmwater and coolwater fish
species . . . that comprise[d] the Hooksett Pool fish community [as of 2013] [was]
comparable to the community that existed in the 1970s.”179 Similarly, the “EPA reviewed
the breakdown in coolwater and warmwater species relative abundance for Garvins and
Hooksett Pools over the sampling period 2010-2013 and found, on average, the two pools
have very similar proportions of warmwater and coolwater species.”180 According to the
EPA, this finding was “consistent with” the conclusion that “the Hooksett Pool fish
community is in similar condition to the upstream Garvins Pool fish community.”181
176 Id. at 216. 177 Id. at 210. 178 Id. at 261. 179 Id. 180 Id. at 234. 181 Id.
59 Further, though the EPA found a “notable decline in fish abundance from both
temperature guilds between the 1970s and the 2010s,” it also noted that the sampling data
from 2010-13 did not indicate “a decreasing trend in abundance for coolwater species,”
further suggesting that “thermal conditions in Hooksett Pool may be improving for the
resident species most sensitive to elevated temperatures . . . .”182
According to the EPA, its review of “mean daily and maximum daily temperature
data during the years 2004 through 2019” revealed further evidence that thermal
conditions in the pool were improving under peaking operations.183 The EPA found that
“when operating as a baseload plant, the thermal plume from the Station frequently
exceeded protective temperatures over multiple days and in consecutive years”; by
contrast, “[t]emperature data from more recent years when the Facility has operated like a
peaking plant[] show[ed] lesser and less frequent instances of water temperatures
exceeding protective levels.”184 For example, “in 2016, which is representative of above
average operating capacity compared to recent summers[,] the mean and maximum daily
temperature at Station S0 only occasionally reached or exceeded avoidance temperatures
for yellow perch[,] and exceedances that did occur were limited to a few days.”185
Similarly, the EPA observed that, under peaking operations, “Merrimack Station operates
infrequently in August and September,” and “in August and September 2016[,] . . .
182 Id. at 235, 240. 183 Id. at 97. 184 Id. at 97-98. 185 Id. at 81.
60 [e]xcursions of protective temperatures for juvenile alewives [at S0 and S4] [we]re
limited in duration and extent.”186
The EPA concluded, based on the above “evidence of improvement, which
correspond[ed] with the [Station’s] reduced operations,” that “the Hooksett Pool BIP will
be protected now and in the future if the Final Permit includes a combination of
operational and temperature limitations that ensure Facility operations maintain current
operational levels . . . .”187 The EPA further found that the “combination of operational
and temperature limitations” in the 2020 Permit will “assure the [continued] protection
and propagation of the BIP.”188 The EPA specified that the 2020 Permit includes “limits
on operation, in combination with acute (maximum daily), water quality-based
temperature limits at Station S4, [which] will ensure that the impacts of the thermal
plume are limited in duration and severity such that the BIP is protected,” and that the
Station cannot “simply shift to higher level operations, such as baseload operations.”189
Deference owed to the EPA’s 2011 and 2020 findings. To begin, the EPA’s 2011
finding that the Station harmed the BIP in the past warrants significant weight and
deference under the Skidmore standard. Indeed, the EPA’s conclusion on this technical
matter is within its expertise. It is also persuasive, as it is the product of extensive
consideration and analysis of fish species’ thermal tolerance, temperature data, and
186 Id. at 77. 187 Id. at 261. 188 Id. at 39. 189 Id. at 105, 137.
61 fisheries data. Furthermore, during trial, the defendants’ expert, Dr. Barnthouse, agreed
with two of the EPA’s key conclusions from its 2011 BIP analysis. Dr. Barnthouse
testified that “the capacity of the [S]tation’s thermal discharge to adversely impact the
[balanced, indigenous community] [was] significant” as of 2011,190 and “there was a shift
from” the fish community present in the late 1960s or early 1970s to “what appears to be
a more heat-tolerant community” by 2011.191
The EPA’s findings regarding the status of the BIP in 2020 are also worthy of
significant deference, for the very same reasons—the findings concern technical matters
and are the product of the EPA’s expertise and reasoned analysis of relevant data. The
court is particularly persuaded by the EPA’s logical and comprehensive review of the data
available to it.
For example, when reviewing temperature data, the EPA focused on daily and
short-term averages instead of long-term averages. The EPA acknowledged that its
“consideration of the actual, daily temperature data is consistent with comments received
from” the plaintiffs in this case, which urged the EPA to “consider the long-term,
comprehensive continuous monitoring data for the three locations in the Merrimack River
[Stations N10, S0, and S4], instead of relying on high-level summaries that hide peak
temperatures and variation over time.”192 Further, the EPA reasonably took into
consideration the Station’s shift in operations in 2012 when assessing the relationship
190 Trial Tr. 10.25.22 PM (Barnthouse) at 82:3-7. 191 Id. (Barnthouse) at 82:8-17. 192 2020 Response to Comments (Defs.’ Ex. 9) at 62 n.6.
62 between the Station’s discharges and the BIP. The EPA did this by reviewing fish
sampling and temperature data from 2012 and afterwards, and comparing it with fish
sampling and temperature data from earlier periods. Finally, before setting temperature
limits for the 2020 Permit, the EPA considered a “wide range of studies to determine
appropriate temperatures for protecting the BIP.193 The temperature limits also complied
with the EPA’s “1986 Water Quality Criteria (“Gold Book”), which establishes a
maximum protective temperature for short exposures based on species-specific
equations.”194
In considering the persuasiveness of the EPA’s 2020 determinations, the court also
finds it noteworthy that Dr. Jordaan expressed agreement with at least one aspect of the
EPA’s analysis. He testified, consistent with the EPA’s opinion, that the Hooksett and
Garvins Pools “are reflective of each other,” and the similarities that the EPA found in the
fish communities in the pools “provides evidence on the side of supporting th[e] [EPA’s]
finding” that the BIP is currently protected.195 In sum, the EPA’s 2020 findings are well-
reasoned, thorough, supported by relevant data and evidence, and internally consistent,
and the court accordingly places significant weight on them.
In deferring to the EPA’s 2020 determinations, the court recognizes that they are
not necessarily final, nor are they impenetrable. For example, the plaintiffs raise at least
three reasonable challenges to the EPA’s conclusion that the 2020 Permit requirements
193 Id. at 95. 194 Id. 195 Trial Tr. 10.20.22 AM (Jordaan) at 99:21-100:12.
63 will ensure the protection of the BIP. These challenges bear some (though not
commanding) weight, and are thus worth noting in brief.
First, the plaintiffs suggest that the EPA’s 2020 determinations are based on
insufficient fish sampling data from the period following the Station’s transition to a
peaking facility. The court agrees that the EPA only had two years of fish sampling data
(from 2012 and 2013) on which to conclude that the status of the BIP was improving and
protected under peaking operations. This two-year period can be considered relatively
limited in duration, but that does not necessarily negate the accuracy or importance of the
observations that the EPA drew from the data.
The plaintiffs’ concerns about the limited fish sampling data reflecting peaking
operations are also mitigated by two facts that are apparent from the record. First, Part
I.C of the 2020 Permit is presently in effect and requires two consecutive years of fish
sampling.196 This sampling commenced in 2022 under a sampling plan that the
defendants developed and the EPA approved.197 Second, the EPA has shown a
willingness to adjust Permit requirements based on new data or changed circumstances.
Indeed, the EPA reopened the public comment period to address the Station’s operational
changes in 2012, and it stated in the 2020 Response to Comments that, “[i]f it turns out
196 2020 Permit (Defs.’ Ex. 8) at Part I.C; see also Pls.’ Ex. 71 at 3 (identifying the 2020 Permit provisions that are stayed, and those that are uncontested and fully effective as of October 1, 2020). 197 See Approved Sampling Plan (Defs.’ Ex. 97); Trial Tr. 11.2.22 AM (Tillotson) at 7:15-8:10 (confirming that the EPA reviewed and approved the defendants’ fish sampling plan); Trial Tr. 11.7.22 AM (Varney) at 49:4-22 (confirming that fish sampling as required under Part I.C of the 2020 Permit commenced in July 2022).
64 that the Final [2020] Permit’s thermal discharge limits are not adequately protective, they
can be appropriately tightened in the future.”198 These facts inspire at least some
confidence that the EPA will consider newly gathered fish sampling data and adjust
Permit requirements accordingly.
Next, the plaintiffs argue that the Delta-T and Capacity Factor Alternative
Compliance Conditions cannot be protective of the BIP because the former lacks a proper
foundation and the latter was remanded by the EAB because the EPA “failed to provide
adequate notice” of the condition before issuing the 2020 Permit.199 While these
arguments are not unreasonable, they do not persuade the court to significantly discount
the EPA’s 2020 determinations, for the reasons stated below.
To begin, the EPA provided at least some reasoning for both of these Alternative
Compliance Conditions in the 2020 Response to Comments. The EPA explained that the
Delta-T condition “provides the Permittee with flexibility to meet the effective permit
limits when ambient temperatures in the river may reach or exceed” them and also
“addresses” the possibility that fish have higher thermal tolerance levels than reflected in
laboratory studies.200 Relatedly, the EPA recognized that fish may sometimes withstand
higher temperatures than those reported in studies, as “laboratory studies of temperature
tolerance acclimate fish at a constant temperature, but under natural conditions fish are
198 2020 Response to Comments (Defs.’ Ex. 9) at 332. 199 EAB Remand Order (Pls. Ex. 72) at 37. 200 2020 Response to Comments (Defs.’ Ex. 9) at 157.
65 exposed to a range of temperatures,” including higher acclimation temperatures during
warm weather, which “typically correspond with higher temperature tolerances.”201
As for the Capacity Factor condition, the EPA explained that “[a] rolling, 45-day
average capacity factor of 40% from May 1 through September 30 allows the Facility to
continue to operate during the summer as it has in recent years (in fact, in most years the
45-day average capacity factor was less than 40%) while limiting the impacts of the
thermal plume on the aquatic community.”202 The EPA further explained why it selected
a 45-day period for the Capacity Factor condition, and not a longer or shorter period, as
follows. “A 45-day rolling average strikes a balance between limiting the number of days
a facility can operate in a row and requiring sufficient ‘downtime’ when the Facility is not
operating to allow the river to recover to ambient temperatures.”203 Neither of these
rationales are extensive, but they warrant some deference under Skidmore as products of
the EPA’s expertise on matters of a highly technical nature.
The plaintiffs, meanwhile, marshalled extremely limited evidence challenging the
substance of these conditions at trial. The plaintiffs questioned Dr. Barnthouse about the
Delta-T Alternative Compliance Condition, and he testified that he did not “have” a
biological or scientific basis for the 2˚ C buffer reflected in the condition, and he did not
know where the buffer “came from.”204 Aside from this testimony, the plaintiffs did not
201 Id. at 153. 202 Id. at 39 n.4. 203 Id. 204 Trial Tr. 12.2.22 PM (Barnthouse) at 47:2-9.
66 set forth any expert opinions critiquing the two conditions. Without more, and more
specific, expert opinions weighing against the validity of these two conditions, the
plaintiffs’ attempts to invalidate these aspects of the Permit are of limited persuasive
effect.
2. The defendants’ evidence
As previously noted, in countering the plaintiffs’ claim, the defendants rely in
large part on the EPA’s 2020 findings that the BIP will remain protected under the
Station’s peaking operations and the 2020 Permit requirements. The defendants also
presented credible evidence demonstrating that the Station has complied with the 2020
Permit requirements since 2020.
The defendants entered into evidence an exhibit that summarizes the Station’s
capacity factor as well as temperature data gathered at the monitoring probes in the pool,
and compares this data to the 2020 Permit’s thermal and operational limits. The chart
focuses on four compliance criteria in the 2020 Permit—the weekly average temperature
limits, the daily maximum temperature limits, the 45-day Capacity Factor Alternative
Compliance Condition, and the Delta-T Alternative Compliance Condition.205 The chart
also focuses on the periods of May through September of 2018 through 2021, as well as
May through June of 2022. These years reflect the period since the defendants assumed
ownership of the Station, and May through September covers the months when the
maximum daily temperature limits and the Capacity Factor Alternative Compliance
205 See Defs.’ Ex. 31.
67 Condition apply.206 The chart indicates that capacity factor data was not yet available for
the period beginning in July 2022, and certain temperature data was not yet available for
the period beginning in August 2022.207 Thus, the chart does not contain the necessary
information to determine compliance after June 2022.
Elizabeth Tillotson, the Vice President of the defendant organizations,208 testified
that she completed the calculations in chart,209 and she explained how she completed
them. She gathered data on the Station’s capacity factor from the EPA’s Clean Air
Markets Program Database, a publicly available database that catalogues power plant
emissions, including the variable she used, which captures gross generation.210 She
calculated the average weekly and maximum reported daily temperatures using the 15-
minute temperature data gathered at both stations.211 She also followed the 2020 Permit’s
instructions regarding how to calculate the Station’s 45-day average capacity factor,
weekly average temperatures, and daily maximum temperatures.212
The chart shows that the defendants have complied with the 2020 Permit’s thermal
limits from May through September of 2020 and 2021, as well as May through June of
206 Trial Tr. 11.2.22 AM (Tillotson) 12:8-14, 14:12-18. 207 See Defs.’ Ex. 31 at 6. 208 Doc. no. 93 at AF ¶ 11. 209 Trial Tr. 11.2.22 AM (Tillotson) at 10:23-24. See Clean Air Market Program Data, available at https://campd.epa.gov/data/custom-data- 210
download; Trial Tr. 11.2.22 AM (Tillotson) at 11:11-16. 211 Trial Tr. 11.2.22 AM (Tillotson) 11:9-10. 212 Id. (Tillotson) at 14:19-24, 15:11-17, 18:22-19:4, 20:4-12.
68 2022. During any period in which weekly temperature limits were exceeded, the Permit
conditions were still satisfied under the Capacity Factor or Delta-T Alternative
Compliance Conditions. The plaintiffs do not meaningfully challenge Tillotson’s
calculations or underlying data for these periods, and the court finds both to be
reasonable and reliable.
3. The plaintiffs’ evidence
The plaintiffs presented a variety of evidence in an attempt to prove that the
Station’s thermal discharge continues to harm the BIP, contrary to the EPA’s
determination in 2020. Below, the court summarizes the more substantial evidence
offered by the plaintiffs and assesses its persuasiveness.
First, Dr. Jordaan testified that the Station’s shift to peaking operations did not
bring about “an improvement in any way” because it “replaced one negative impact,
which was the chronic exposure to high temperatures[,]” with another—“frequent[,] very
high change[s] in temperature . . . in the summer and winter months while [ ] Merrimack
Station is running.”213 According to Dr. Jordaan, these “rapid thermal changes,” which
are referred to as heat or cold shock, “ha[ve] a range of physiological and behavioral
consequences from short term impairment to death.”214 Dr. Jordaan also asserted that
heat and cold shock favor thermally-tolerant fish species, as those species are best able to
“cope with [these] wild temperature changes.”215
213 See 10.19.22 PM Trial Tr. (Jordaan) at 23:2-10, 63:23-64:1. 214 Jordaan Expert Report (Pl. Ex. 19) at 6. 215 10.19.22 PM Trial Tr. (Jordaan) at 23:10-11; Jordaan Expert Report (Pl. Ex. 19) at 23.
69 Dr. Jordaan provided examples of these purportedly rapid temperature swings
during both summer and winter. For example, in the summer, Dr. Jordaan identified
“frequent changes of greater than 1˚ C [per hour] both in increases and decreases” at
Station S4 on July 19, 2019.216 He also opined that fish that enter the cooling canal when
the Station is not operating can face more severe temperature swings and lethal
temperatures when operations commence.217 As for the winter months, temperature data
recorded at Station S0 indicated that “plant operations during the winter cause
temperature spikes that frequently exceed[ed] 10˚ C[elsius]” in 2019.218
The court credits this sound evidence of occasional temperature swings, as well as
Dr. Jordaan’s opinion that they can create detrimental conditions for fish during peaking
operations. This evidence is minimally persuasive when it comes to demonstrating a
Permit violation, however, because the plaintiffs do not effectively establish that the
temperature swings affect, or are likely to affect, the BIP.
Indeed, several statements in Dr. Jordaan’s report indicate an uncertainty about
the impact of temperature swings on the fish in the pool. He wrote in his report that
“[t]he extent and impact of these rapid temperature changes has not been detailed in any
past work, nor have the extent or persistence of thermal plumes.”219 He also asserted that
the temperature swings “will impact coldwater species more,” and he provided examples
216 Jordaan Expert Report (Pl. Ex. 19) at 23. 217 Id. 218 Id. at 10. 219 Id. at 11.
70 of potentially harmful temperature swings in July and August of certain years, but he also
suggested that coolwater species may not be present in the Hooksett Pool during those
two months because the “background thermal conditions” would likely not “support”
them at that time of year.220
The effect of temperature swings in the winter is similarly unspecified. Dr.
Jordaan acknowledged that “[t]he impact of altered thermal regime,” including
temperature swings, “during the winter is far less certain, since no monitoring for the
extent of the plume has occurred” in the winter.221 He also wrote in his report that
“fluctuations in temperature during winter months are more severe,” but “research
suggests that absolute temperatures are more impactful for heat and cold shock effects,
thus the timing and background temperatures and which species are present will be
important in determining impacts. In short, while data is lacking, there is reason to think
that the rapid temperature swings caused by the Merrimack Station’s winter operations
harm native coldwater species such as brook trout and blacknose dace.”222
The EPA’s 2020 Response to Comments contains additional, credible evidence
that weakens the force of Dr. Jordaan’s opinion with respect to cold shock in the winter,
specifically. The EPA opined that the effect of cold shock in the winter is limited when
the Station operates as a peaking plant, since there is “minimal to no need for the facility
to operate during much of the fall[,] . . . [and] [t]his allows resident species to adjust
220 Id. 221 Id. at 23. 222 Id. at 11.
71 naturally to colder ambient temperatures throughout the Hooksett Pool.”223 As a result,
the EPA reasoned, “the potential for cold shock to occur would be limited to only those
fish within the [cooling] canal and not the Hooksett Pool proper where the plume’s
temperature drops fairly quickly as it comes in contact with the ambient river water and
dissipates.”224 Dr. Jordaan testified at trial that he agreed with this conclusion.225
In short, Dr. Jordaan’s opinion regarding the relationship between temperature
swings and the status of the BIP lacks clarity and borders on speculative. As a result, the
plaintiffs lack persuasive evidence that the occurrence of temperature swings in the
Hooksett Pool in the summer and winter constitutes a likely Permit violation.
Second, the plaintiffs contend that the Station’s discharges have changed or
harmed the BIP by bringing about an invasive Asian clam population in the thermally-
affected portions of the pool. As support for this argument, the plaintiffs point to the
EPA’s findings and comments within the 2020 Response to Comments. The EPA asserted
that the Asian clam is “an invasive species with an affinity for warmer water temperatures
than typically found in the Merrimack River under ambient conditions.”226 It also found
that “quantitative” and “semi-quantitative” sampling from 2014 and 2016 revealed that
Asian clams were “presen[t] throughout the thermally-influenced portion of Hooksett
223 2020 Response to Comments (Defs.’ Ex. 9) at 137. 224 Id. 225 See Trial Tr. 10.20.22 AM (Jordaan) at 74:24-75:20. 226 2020 Response to Comments (Defs.’ Ex. 9) at 269.
72 Pool,” and were “absen[t] in the ambient area directly upstream.”227 The EPA was
accordingly “convinced that the abundance of Asian clams in the thermally-influenced
portion of the Hooksett Pool . . . is directly related to the [the] Station’s thermal
discharge.”228
Critically, the EPA concluded that the “Asian clam has the potential to adversely
alter the BIP of the Hooksett Pool” by, for example, competing with “native fish and
shellfish species for food and space,” but “based on the information provided to date, it
appears that the effects associated with the Asian clams’ presence and abundance has not
caused appreciable harm to the . . . BIP.”229 The EPA partially based this conclusion on a
commenter’s analysis of the “differences in the abundance and species richness in native
invertebrates upstream and downstream of the Facility’s thermal discharge.”230 Finally,
the EPA noted that the effect of Asian clam population on the BIP will be monitored
under the 2020 Permit.231
As an initial matter, the EPA’s conclusions are entitled to deference based, at the
very least, on the EPA’s expertise, the technical nature of this matter, and the EPA’s
reliance on at least some relevant evidence. See supra Section III.B. On balance, the
EPA’s conclusions weigh heavily against the plaintiffs’ position. The EPA’s statements
227 Id. at 268, 271. 228 Id. at 271. 229 Id. at 270 (emphasis added). 230 Id. 231 Id. at 271.
73 regarding the Asian clam’s potential ability to harm the BIP and the importance of
monitoring the population lend some limited support to the plaintiffs’ argument. But
these statements are less definitive than the EPA’s determination that the clams are not
yet harming the BIP. Moreover, the plaintiffs do not offer expert testimony refuting the
EPA’s conclusion that the BIP remains protected currently, despite the presence of Asian
clams. Indeed, Dr. Jordaan does not provide any opinion on the Asian clam population in
the lower Hooksett Pool.232 Nor do the plaintiffs offer convincing evidence that the very
presence of the clams constitutes a change, or harm, to the BIP. As such, evidence of the
presence and abundance of the Asian clam population does not advance the plaintiffs’
Third, Dr. Jordaan considered a subset of the available fish sampling data to
conclude that “warm water fish are favored in the Hooksett Pool.”233 He stated that the
pool has a “low diversity of species . . . compared to other river reaches[,] and . . . [is]
domina[ted] by thermally tolerant non-native species, although cold water species are
present upstream and in tributaries.”234 Dr. Jordaan further noted that the “most abundant
fish in the Hooksett Pool are those with the highest thermal optimal and lethal limits.”235
According to Dr. Jordaan, these population characteristics indicate that the pool provides
232 See Jordaan Expert Report (Pls.’ Ex. 19) (containing no opinion on the Asian clam population); Jordan Expert Rebuttal Report (Pls.’ Ex. 20) (same). 233 Jordaan Expert Report (Pls.’ Ex. 19) at 21. 234 Id. at 11. 235 Id. at 7.
74 a “low quality environment in which [some fish species inhabiting the Merrimack River]
cannot survive and reproduce to become self-sustaining.”236
The court places little weight on this portion of Dr. Jordaan’s opinion because it
rests on less comprehensive and less recent fish sampling data than the EPA’s
contradictory findings. See Ferrara & DiMercurio v. St. Paul Mercury Ins. Co., 240 F.3d
1, 9 (1st Cir. 2001) (“When the factual underpinning of an expert opinion is weak, it is a
matter affecting the weight and credibility of the testimony—a question to be resolved by
the jury” (quoting Newell P.R., Ltd. v. Rubbermaid Inc., 20 F.3d 15, 21 (1st Cir. 1994))).
Specifically, Dr. Jordaan did not incorporate Normandeau’s 2010-13 fish sampling data
into his analysis. Instead, Dr. Jordaan drew his conclusions from fish sampling data
gathered by the New Hampshire Fish and Game Department and from Normandeau’s
2011 analysis, which was limited to sampling conducted during or before 2005.237
Dr. Jordaan testified about the differences among these data sources and the
relative superiority of Normandeau’s 2010-13 fish sampling data at trial. He agreed that
Normandeau’s 2010-13 sampling is “intensive,” and the NHF&GD sampling he relied on
was “extensive.”238 In Dr. Jordaan’s words, intensive sampling involves “significant
effort in a single location,” whereas extensive sampling involves “one pass or limited
sampling but in a larger extent of area.”239 He also testified that Normandeau’s 2010-13
236 Id. at 11. 237 Id. at 7. 238 Trial Tr. 10.20.22 AM (Jordaan) at 67:14-20. 239 Id. (Jordaan) at 66:16-21.
75 study was “the most intensive sampling available” and “the best [evidence,] of what has
been done thus far.”240
Nevertheless, Dr. Jordaan did not incorporate this evidence into his analysis of the
fish population in the Hooksett Pool.241 This oversight of admittedly reliable and
valuable data severely undermines Dr. Jordaan’s opinion because, based on the EPA’s
credible analysis, the 2012-13 sampling data reveals improvements in the BIP associated
with the Station’s peaking operations. In other words, Dr. Jordaan’s opinion lacks
credibility because he declined to confront important, relevant data that weighs against
his conclusions.
Fourth and finally, the plaintiffs point to temperature data from 2018 through
2022, which they contend shows that the Station’s operations caused temperatures in the
pool to rise in a manner that taxes fish and is harmful to the BIP. For example, Dr.
Jordaan credibly asserted in his report that in July 2019, the Station operated for 140
hours, and the average difference in temperature between N10 and S4 was 1.41˚ C. 242 He
further explained that “[t]he biological consequences of a 1-2˚ C change in average
summer water temperatures are significant both as to lethal and sub-lethal impacts.”243
The plaintiffs pair this data with Dr. Jordaan’s opinion that background temperatures in
240 Id. (Jordaan) at 66:22-67:5, 68:24-69:5. 241 See id. (Jordaan) at 70:23-71:1 (“Q. And you didn't use the [Normandeau fish sampling] data that was more recent of the Hooksett Pool? A. I did not use it, no.”). 242 Jordaan Expert Report (Pls.’ Ex. 19) at 24. 243 Id.
76 the pool already approach or exceed the tolerance levels for various species in some
years, and at those times, the Station’s operations further endanger fish that are already
under threat.244
The plaintiffs also identified a period from July 8 through August 14, 2022, when
average temperatures at N10 exceeded optimal ranges for certain resident fish, and
temperatures at S0 and S4 were higher.245 When presented with these averages at trial,
Dr. Barnthouse concluded that “[i]f [he] had to make a determination only on
exceedances of [] laboratory-derived benchmarks,” as opposed to direct field data on the
composition of the fish population, he would conclude that these thermal conditions were
not consistent with the protection of the BIP.246
While this evidence could benefit from more specificity as to the frequency and
duration of temperature exceedances—parameters that the EPA repeatedly considered
relevant to the biological implications of heat for fish—the court nevertheless finds it
worthy of some weight. Indeed, Dr. Jordaan’s opinion is consistent with the accepted
principle that exceedances of preferred temperature ranges can harm the health and
survival of fish who are exposed to them. The court also finds it noteworthy that this data
244 See Trial Tr. 12.2.22 PM (Jordaan) at 106:1-13 (“I don’t doubt that in some cases in some years in the Merrimack River . . . the background temperatures[ ] are near the limits of certain species. The issue is that, by then adding more heat to it, you increase that impact quite substantially. . . . [B]ecause the species would be at a stressed, somewhat stressed level, they’re even less capable of dealing with those temperature changes, the swings, in particular, but also the increase as time moves on.”). 245 See Trial Tr. 12.2.22 AM (Barnthouse) at 76:12-77:25. 246 Id. (Barnthouse) at 79:7-17.
77 comes from recent years, some of which the EPA could not consider when rendering its
determinations in the 2020 Response to Comments.
The weight of this evidence is partially mitigated by one factor, however—water
temperature and thermal tolerance data are indirect indicators of the status of the BIP.
Indeed, during trial, Dr. Jordaan agreed with the proposition that “studies and fieldwork
in the Hooksett Pool,” such as fish sampling data, “would be the best evidence of what’s
happening out there.”247 Dr. Barnthouse similarly testified that “field data . . . gives a
better indication of what the fish community looks like than do[es] the thermal tolerance
data.”248 The court agrees with the logic of these statements, but, as previously stated,
still places some weight on the temperature data as evidence of potential harm to the BIP.
4. Conclusion (Count 2)
In sum, of the evidence that the plaintiffs have presented to demonstrate that the
Station is violating the Permit by changing the BIP, the court is persuaded, in part, by the
temperature data showing some exceedances of optimal temperatures from 2018 through
2022. The weight of this evidence is limited because it is an indirect measure of the
status of the BIP, and Dr. Jordaan has conceded that more direct and highly relevant data
(Normandeau’s fish sampling data from 2010-13) was available, but he did not consider
it.
247 Trial Tr. 10.20.22 AM (Jordaan) at 66:7-13. 248 Trial Tr. 12.2.22 AM (Barnthouse) at 79:12-17.
78 Meanwhile, the EPA’s determinations that the Station’s peaking operations are not
harming the BIP, and that the 2020 Permit requirements will assure the future protection
of the BIP, are worthy of considerable deference, as they rest on the EPA’s technical
expertise, sound reasoning, and recent and relevant data. The EPA’s conclusions
regarding the protective nature of the 2020 Permit requirements, however, must be
discounted to a limited extent given that they may be subject to change, and they present
other shortcomings in reasoning and evidentiary support, as discussed above.
On balance, the court concludes that the EPA’s 2020 determinations regarding the
BIP command more weight than the plaintiffs’ opposing evidence, given that the EPA’s
findings warrant deference under Skidmore and the plaintiffs’ strongest evidence
contradicting them is indirect and limited in quantity and quality. The EPA’s 2020
determinations, when combined with the Station’s record of compliance with the 2020
Permit requirements during the summer and fall months following the Permit’s issuance,
indicate that the Station current and ongoing operations are unlikely to violate the Permit
by changing the BIP. The court accordingly rules that the plaintiffs have not proven a
Permit violation as alleged in Count 2 by a preponderance of the evidence.249
249 The court emphasizes here that the burden of proof rests with the plaintiffs, and not the EPA or the defendants. Thus, even if the court further discounted the EPA’s 2020 findings for the reasons discussed in this Section, the defendants’ evidence of the Station’s compliance with this Permit provision would (at best) be in equipoise with the plaintiffs’ evidence of the Station’s violations of the provision, and the plaintiffs would still not prevail on this Count. See In re Brady-Zell, 756 F.3d 69, 72 (1st Cir. 2014) (“When the weight of the evidence is in equipoise, a party cannot plausibly be said to have carried the devoir of persuasion” under the preponderance of the evidence standard.).
79 F. State water quality standards (Count 4)
Count 4 is premised on continuing violations of Part I.A.1.b of the Permit, which
provides that “[t]he discharges shall not . . . violate applicable water quality standards.”
The plaintiffs primarily (though not necessarily exclusively) focus this claim on portions
of three New Hampshire statutes which require that the State’s waters support a balanced
community of organisms and recreational uses, particularly fishing.
Specifically, the first statute provides that “[a]ny stream temperature increase
associated with the discharge of . . . cooling water. . . shall not be such as to appreciably
interfere with the uses assigned to this class [of water].” N.H. RSA § 485-A:8(II). In
particular, the Merrimack River, which is designated as Class B water, must remain
“acceptable for fishing, swimming and other recreational purposes and, after adequate
treatment, for use as water supplies.” Id. The second statute provides that “[a]ll surface
waters shall be restored to meet the water quality criteria for their designated
classification including existing and designated uses and to maintain the chemical,
physical, and biological integrity of surface waters.” N.H. Code R. Env-Wq
§ 1703.01(b). Further, “[a]ll surface waters shall provide, wherever attainable, for the
protection and propagation of fish, shellfish and wildlife, and for recreation in and on the
surface waters.” Id. § 1703.01(c). The final statute similarly provides that “[a]ll surface
waters shall support and maintain a balanced, integrated, and adaptive community of
organisms having a species composition, diversity, and functional organization
comparable to that of similar natural habitats of a region,” with “[d]ifferences from
80 naturally-occurring conditions . . . limited to non-detrimental differences in community
structure and function.” Id. § 1703.19(a), (b).
This claim presents significant overlap, in both subject matter and evidence, as the
previous Counts—particularly Count 2. Essentially, the plaintiffs aver that the thermal
conditions within the pool favor warmwater and non-native fish, resulting in an
imbalanced community and an alteration in fishing opportunities, in violation of relevant
state water quality standards.250 The plaintiffs do not prevail on this claim because the
defendants’ evidence of compliance with state water quality standards is more persuasive
than the plaintiffs’ evidence of purported violations.
The court begins with a brief description of the evidence supporting the
defendants’ position. Under Section 401 of the CWA, before a NPDES Permit can be
issued, “the State in which the discharge originates” must certify that the Permit “will not
violate certain water quality standards, including those set by the State’s own laws.” S.D.
Warren Co. v. Maine Bd. of Env’t Prot., 547 U.S. 370, 374 (2006) (citing 33 U.S.C. §
1341(a)(1)); see also 33 U.S.C. § 1341(a)(1) ( “Any applicant for a Federal license or
permit to conduct any activity . . . which may result in any discharge into the navigable
water[s] shall provide the licensing or permitting agency a certification from the State in
which the discharge originates . . . .”). Consistent with this requirement, the New
Hampshire Department of Environmental Services submitted a letter to the EPA in May
250 See Pls.’ Post-trial Findings of Fact (doc. no. 156) at 47-48.
81 2020, in which it certified that the 2020 Permit satisfies the above state water quality
standards.
Specifically, the NHDES wrote that: [a]fter appropriate staff review of the Draft Permit, Fact Sheet, Statement, public comments, and EPA’s response to comments, State Certification is hereby granted pursuant to Section 401 of the Clean Water Act. The permit will ensure that the requirements of Title 50 RSA 485-4, and administrative rule Env-Wq 1700 (Surface Water Quality Regulations) are met.251
In their post-trial brief, the plaintiffs contend that the NHDES’ conclusion on this
matter is too conclusory to warrant deference under Skidmore. The court disagrees.
While the court cannot assess the persuasiveness of the NHDES’ reasoning based on the
record before it, some deference is still appropriate, given the technical nature of the state
water quality standards, the NHDES’ relevant expertise, and the agency’s designated role
in reviewing NPDES permits for compliance with relevant state law. See N.H. RSA 21-
O:1 (establishing the NHDES as the agency responsible for “[w]ater pollution control[,]”
“[w]ater supply protection[,]” and “[r]egulation of water disposal generally,” among other
tasks); see also supra Section III.B. The record does not indicate that the partial stay of
the 2020 Permit alters the NHDES’ conclusion, though the court acknowledges this
possibility and partially limits the weight it places on the NHDES certification
accordingly. In sum, the NHDES certification, along with the defendants’ evidence of
compliance with the 2020 Permit requirements, provides some convincing evidence that
the defendants are not violating the state water quality standards.
251 Defs.’ Ex. 87.
82 The plaintiffs’ evidence of violations of state water quality standards is
significantly less persuasive than the above proof of compliance. First, the plaintiffs do
not offer evidence suggesting that the state standards related to the maintenance of a
balanced community are more stringent than, or otherwise differ from, the 1992 Permit
provision prohibiting the Station from changing the BIP. Accordingly, the court’s
analysis and conclusions with respect to Count 2 apply to this portion of Count 4.
Next, the plaintiffs’ evidence of the Station’s interference with fishing
opportunities is also unconvincing, as it is scant and/or reliant on the unproven premise
that the Station’s discharges are meaningfully changing the BIP in the pool. For instance,
Dr. Jordaan opined in his report that “the [ ] Station’s discharges render the Hooksett Pool
unsuitable for native coldwater and coolwater species; therefore they also interfere with
recreational fishing for such species.”252 Dr. Jordaan added that “[t]he lack of coolwater
species, absence of coldwater species[,] and the presence of thermally tolerant species
that are, in the case of largemouth bass and bluegill, tolerant of degraded habitats (Utz et
al. 2010) are evidence that the water quality standards are not being met.”253
As discussed supra Section III.E.1, in 2020, the EPA came to different conclusions
regarding the status of the pool’s population. For example, the EPA found that, as of
2013, the proportion of coolwater to warmwater species in the Hooksett Pool was
“comparable to the community that existed in the 1970s”;254 the Hooksett and Garvins
252 Jordaan Expert Report (Pls.’ Ex. 19) at 23-24. 253 Id. at 24. 254 Id. at 261.
83 Pools had “very similar proportions of warmwater and coolwater species”;255 and the
2010-13 fisheries data did not demonstrate “a decreasing trend in abundance for
coolwater species.”256 Under these findings, the opportunities to fish for coolwater
species would not have materially changed due to the Station’s operations, as of 2013.
For the reasons stated supra Section III.E, the EPA’s findings regarding the relative
abundance of coolwater species in the pool bear more weight than the plaintiffs’
conflicting evidence, including Dr. Jordaan’s opinion. The plaintiffs accordingly have
not proven ongoing violations of state water quality standards by a preponderance of the
evidence and do not prevail on Count 4.
G. Annual reporting requirements (Count 5)
Count 5 is premised on alleged ongoing violations of Part I.A.13 (“Paragraph 13”)
of the 1992 Permit, which provides that “[a]ll biological and hydrological monitoring
program data shall be submitted to the NHDES, NHF&GD, USG&WS, and the [EPA]
Regional Administrator by December 31 of the following year.” Specifically, the
plaintiffs claim that the defendants continue to violate Paragraph 13 by providing the
agencies with summaries of dissolved oxygen and temperature monitoring data instead of
the entirety of the data, which the defendants collected in 15-minute increments. The
defendants, in turn, contend that they have continuously complied with Paragraph 13 by
submitting summary data.
255 Id. at 234. 256 Id. at 235.
84 The court previously denied the defendants’ motion for summary judgment as to
this Count after finding that each party’s interpretation of Paragraph 13’s reporting
requirements is reasonable under the plain language of the provision.257 Given that
Paragraph 13 is susceptible to differing, reasonable interpretations, the court concluded
that it is ambiguous.258 As noted supra Section III.D.2, when a permit provision is
ambiguous, the court must consider “extrinsic evidence to determine the intent of the
permitting authority,” Piney Run, 268 F.3d at 270, giving “significant weight to any
extrinsic evidence that evinces the permitting authority’s interpretation of the relevant
permit.” Nat. Res. Def. Council, 725 F.3d at 1207.
With these principles in mind, the court recites the undisputed facts relevant to this
inquiry. Paragraph 13 provides reporting requirements for hydrological and biological
data that the permittee is required to monitor under the Permit.259 Each year after the
1992 Permit went into effect, PSNH submitted an Environmental Monitoring Program
Annual Report to the four agencies listed in Paragraph 13.260 Once the defendants
assumed control of the Station in 2018, they began submitting the annual report to the
agencies.261 Each annual report presented temperature and dissolved oxygen data in the
257 See Nov. 25, 2020 Summary Judgment Order (doc. no. 65) at 17-21. 258 Id. at 21. 259 See doc. no. 93 at AF ¶ 100-01; see also 1992 Permit (Defs.’ Ex. 4) at Parts I.A.11-12. 260 Id. at AF ¶ 99. 261 Id.
85 same format.262 Each report contained the daily maximum, daily minimum, and daily
average values for each category of data, as captured at each of the required monitoring
stations.263 On some occasions, the EPA requested the monitoring data in 15-minute
increments for specific time periods, and PSNH or the defendants provided that
information separately from the annual reports.264 Finally, the EPA Fact Sheet issued
alongside the 1992 Permit does not discuss the addition of Paragraph 13 to the Permit.265
This set of facts reveals a consistent course of performance on the part of the
permittee—which submitted temperature and dissolved oxygen data in the same format
each year—and the permitting authority—which occasionally requested 15-minute
temperature data for limited periods but did not request that such data be incorporated
into each report. This undisputed extrinsic evidence uniformly contradicts the plaintiffs’
contention that Paragraph 13 requires the permittee to report the entirety of the 15-minute
monitoring data.
In an attempt to persuade the court otherwise, the plaintiffs suggest that the EPA’s
course of conduct reflects agency inaction, as opposed to the EPA’s interpretation of
Paragraph 13. The court declines to accept this unsubstantiated theory, which is
contradicted by record evidence demonstrating the EPA’s active involvement in
evaluating the Station’s discharges and the thermal conditions of the pool throughout the
262 Id. at AF ¶ 102. 263 Id. at AF ¶¶ 100-01. 264 Id. at AF ¶¶ 106. 265 Doc. no. 93 at AF ¶ 105.
86 permitting process. See, e.g., supra Section III.E.1. The plaintiffs also point to testimony
from Hodge and Dr. Jordaan regarding the utility of 15-minute data for assessing the
behavior of the Station’s thermal plume266 and understanding the “dynamics of what’s
actually happening” in the pool.267 The experts’ opinions about the value of 15-minute
data do not outweigh the EPA’s interpretation of Paragraph 13, as demonstrated by the
agency’s clear and consistent acceptance of the summary data presented in the annual
reports. The plaintiffs’ evidence on this Count accordingly falls far short of a
preponderance, and the court rules in the defendants’ favor on Count 5.
The clerk shall enter judgment and close the case.
SO ORDERED.
_________________________ Joseph N. Laplante United States District Judge
Dated: December 6, 2023
cc: Reed Super, Esq. Edan Rotenberg, Esq. Bridget Denzer, Esq. Julia Kathryn Muench, Esq. Meaghan A. Jepsen, Esq. Thomas F. Irwin, Esq. Wilbur A. Glahn, III, Esq. Amanda Ellen Quinlan, Esq. Jennifer L. Parent, Esq. P. Stephen Gidiere, III, Esq. Thomas G. DeLawrence, Esq.
266 See Trial Tr. 10.18.22 AM (Hodge) at 73:20-74:7. 267 See Trial Tr. 10.19.22 AM (Jordaan) at 108:15-109:4.
Related
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