United States Court of Appeals

FOR THE DISTRICT OF COLUMBIA CIRCUIT

Argued February 24, 2014 Decided June 6, 2014

No. 13-1015

DELAWARE RIVERKEEPER NETWORK, ET AL.,

PETITIONERS

v.

FEDERAL ENERGY REGULATORY COMMISSION,

RESPONDENT

TENNESSEE GAS PIPELINE COMPANY, LLC AND STATOIL 

NATURAL GAS, LLC,

INTERVENORS

On Petition for Review of an Order

of the Federal Energy Regulatory Commission

Aaron Stemplewicz argued the cause for petitioners. With 

him on the briefs was Susan Kraham. Jane P. McClintock

entered an appearance.

Karin L. Larson, Attorney, Federal Energy Regulatory 

Commission, argued the cause for respondent. With her on 

the brief were David L. Morenoff, Acting General Counsel, 

and Robert H. Solomon, Solicitor.

John F. Stoviak argued the cause for intervenors. With 

him on the brief were Pamela S. Goodwin, Thomas S. 
2

Schaufelberger, William G. Myers III, and Kirstin Elaine 

Gibbs. Christopher M. Heywood entered an appearance.

Before: BROWN, Circuit Judge, and EDWARDS and 

SILBERMAN, Senior Circuit Judges.

Opinion for the Court filed by Senior Circuit Judge

EDWARDS.

Opinion filed by Circuit Judge BROWN concurring in part 

and concurring in the judgment. 

Concurring opinion filed by Senior Circuit Judge 

SILBERMAN.

EDWARDS, Senior Circuit Judge: In May 2012, the 

Federal Energy Regulatory Commission (“Commission” or 

“FERC”) issued a certificate of public convenience and 

necessity to Tennessee Gas Pipeline Company, L.L.C. 

(“Tennessee Gas”), authorizing it to build and operate the 

Northeast Upgrade Project (“Northeast Project”). The project 

included five new segments of 30-inch diameter pipeline, 

totaling about 40 miles, and modified existing compression 

and metering infrastructure. Petitioners, Delaware 

Riverkeeper Network, New Jersey Highlands Coalition, and 

Sierra Club, New Jersey Chapter (collectively, 

“Riverkeeper”), contend, inter alia, that in approving the 

Northeast Project, FERC violated the National Environmental 

Policy Act (“NEPA”), 42 U.S.C. §§ 4321-4370h, by: (1) 

segmenting its environmental review of the Northeast Project 

– i.e., failing to consider the Northeast Project in conjunction 

with three other connected, contemporaneous, closely related, 

and interdependent Tennessee Gas pipeline projects – and (2) 

failing to provide a meaningful analysis of the cumulative 
3

impacts of these projects to show that the impacts would be 

insignificant. 

The Northeast Project upgraded a portion of a much 

longer natural gas pipeline known as the 300 Line. Taken 

together, the Northeast Project and the three other connected, 

closely related, and interdependent Tennessee Gas upgrade 

projects on the 300 Line constituted a complete upgrade of 

almost 200 miles of continuous pipeline. FERC was 

responsible for the environmental review of these projects 

because, under the Natural Gas Act, any party seeking to 

construct a facility for the transportation of natural gas in 

interstate commerce must first obtain a certificate of public 

convenience and necessity from the Commission. 15 U.S.C. 

§ 717f(c)(1)(A). And before FERC may issue such a 

certificate, it must satisfy the requirements of NEPA by 

identifying and evaluating the environmental impacts of the 

proposed action. This means that FERC was required to 

prepare an Environmental Assessment (“EA”) and, if 

significant impacts were found, to prepare a more 

comprehensive Environmental Impact Statement (“EIS”). 40 

C.F.R. § 1501.4.

The 300 Line carries natural gas from wells in western 

Pennsylvania to points of delivery east of Mahwah, New 

Jersey. When it was first constructed in the 1950s, the entire 

pipeline was built of 24-inch diameter pipe, with compressor 

stations located every several miles to keep the gas moving 

through the pipeline. The 300 Line has a Western Leg and an 

Eastern Leg. Expansions to the Western Leg of the pipeline 

added 30-inch diameter pipe and allowed it to accommodate 

skyrocketing natural gas production in the Marcellus Shale 

region, a drilling area that spreads across western 

Pennsylvania and neighboring states. By 2010, the Western 

Leg consisted of parallel, connected 24-inch and 30-inch 
4

pipes, while the Eastern Leg consisted almost entirely of 24-

inch pipe. 

In 2010, the pipeline’s owner, Tennessee Gas, 

commenced construction of what has turned out to be a 

complete overhaul of the Eastern Leg of the 300 Line. 

Tennessee Gas’s upgrades to the Eastern Leg have included 

construction of new 30-inch pipe segments, as well as 

renovations to compression and monitoring infrastructure. As 

with the Western Leg, the improvements to the Eastern Leg 

produced parallel and connected 24-inch and 30-inch pipes. 

The result was fifteen interlocking loop segments of new 

pipeline that completed a full and continuous upgrade of the 

Eastern Leg of the 300 Line.

Tennessee Gas submitted four separate project proposals 

to FERC for the upgrade work on the Eastern Leg. The four 

upgrade projects – the third being the Northeast Project –

were reviewed separately by FERC, approved, and then 

constructed in rapid succession between 2010 and 2013.

In November 2011, FERC completed the EA for the 

Northeast Project – the project that is the subject of the 

petition for review in this case – and recommended a Finding 

of No Significant Impact. FERC’s NEPA review of the 

Northeast Project did not consider any of the other upgrade 

projects, even though the first upgrade project was under 

construction during FERC’s review of the Northeast Project, 

and even though the applications for the second and fourth 

upgrade projects were pending before FERC while it 

considered the Northeast Project application. In May 2012, 

the Commission approved the Northeast Project, 

incorporating its EA and the Finding of No Significant Impact 

and issuing a certificate of public convenience and necessity 
5

to Tennessee Gas. Tenn. Gas Pipeline Co., 139 FERC 

¶ 61,161, 2012 WL 1934728 (May 29, 2012) (“Order”). 

Petitioners contend that FERC violated NEPA when it 

segmented its review of the Northeast Project, giving no 

consideration to that project in conjunction with the three 

other connected, contemporaneous, closely related, and 

interdependent Eastern Leg projects. Petitioners also claim 

that FERC failed to provide a meaningful analysis of the 

cumulative impacts of these projects to show that the impacts 

would be insignificant. 

FERC argues that because each project resulted in a 

measurable increase in the pipeline’s overall capacity, the 

agency was justified in completing the NEPA analysis of the 

Northeast Project separately from the other projects. But 

FERC’s position cannot be squared with the record, which 

shows that by May 2012, when FERC issued the certificate 

for the Northeast Project, it was clear that the entire Eastern 

Leg was included in a complete overhaul and upgrade that 

was physically, functionally, and financially connected and

interdependent. During the pendency of Tennessee Gas’s 

Northeast Project application, the other three projects that 

would constitute the revamped Eastern Leg were either under 

construction or were also pending before the Commission for 

environmental review and approval. Given the self-evident 

interrelatedness of the projects as well as their temporal 

overlap, the Commission was obliged to consider the other 

three other Tennessee Gas pipeline projects when it conducted 

its NEPA review of the Northeast Project.

Under applicable NEPA regulations, FERC is required to 

include “connected actions,” “cumulative actions,” and 

“similar actions” in a project EA. 40 C.F.R. § 1508.25(a). 

“Connected actions” include actions that are “interdependent 
6

parts of a larger action and depend on the larger action for 

their justification.” Id. § 1508.25(a)(1)(iii). The four pipeline 

improvement projects are certainly “connected actions.” 

There is a clear physical, functional, and temporal nexus 

between the projects. There are no offshoots to the Eastern 

Leg. The new pipeline is linear and physically interdependent; 

gas enters the system at one end, and passes through each of 

the new pipe sections and improved compressor stations on its 

way to extraction points beyond the Eastern Leg. The upgrade 

projects were completed in the same general time frame, and 

FERC was aware of the interconnectedness of the projects as 

it conducted its environmental review of the Northeast 

Project. The end result is a new pipeline that functions as a 

unified whole thanks to the four interdependent upgrades. 

FERC has not shown that there are logical termini 

between the new segments of the Eastern Leg or that each 

project resulted in a segment that has substantial independent 

utility apart from the other parts of the Eastern Leg. Rather, 

FERC merely argues that one terminus was “no more logical 

than another,” Br. of Resp’t at 25, and that the capacity added 

by each project was contracted separately. These explanations 

are insufficient to address Riverkeeper’s segmentation claim. 

On the record before us, we hold that in conducting its 

environmental review of the Northeast Project without 

considering the other connected, closely related, and 

interdependent projects on the Eastern Leg, FERC 

impermissibly segmented the environmental review in 

violation of NEPA. We also find that FERC’s EA is deficient 

in its failure to include any meaningful analysis of the 

cumulative impacts of the upgrade projects. We therefore 

grant the petition for review and remand the case to the 
7

Commission for further consideration of segmentation and 

cumulative impacts.

I. BACKGROUND

A. Applicable Statutory and Regulatory Framework

The Natural Gas Act grants FERC jurisdiction over the 

transportation and wholesale sale of natural gas in interstate 

commerce. 15 U.S.C. § 717(b)-(c). Any person seeking to 

construct or operate a facility for the transportation of natural 

gas in interstate commerce must first obtain a certificate of 

public convenience and necessity from the Commission. Id. 

§ 717f(c)(1)(A). FERC is authorized to issue such a certificate 

to any qualified applicant upon finding that the proposed 

construction and operation of the pipeline facility is required 

by the public convenience and necessity. Id. § 717f(e).

NEPA requires that federal agencies fully consider the 

environmental effects of proposed major actions, including 

actions that an agency permits, such as pipeline construction.

42 U.S.C. § 4332(2)(C); see also La. Ass’n of Indep. 

Producers & Royalty Owners v. FERC, 958 F.2d 1101 (D.C. 

Cir. 1992). FERC is therefore responsible for the NEPA 

review associated with natural gas pipeline construction. 

Midcoast Interstate Transmission, Inc. v. FERC, 198 F.3d 

960, 967 (D.C. Cir. 2000).

After determining the scope of the federal action, an 

agency produces an EA, which is a “concise public 

document” that “provide[s] sufficient evidence and analysis 

for determining whether to prepare an environmental impact 

statement or a finding of no significant impact.” 40 C.F.R. 

§ 1508.9. The scope of an agency’s NEPA review must 

include both “connected actions” and “similar actions.” Id. 
8

§ 1508.25(a)(1), (3). Actions are “connected” if they trigger 

other actions, cannot proceed without previous or 

simultaneous actions, or are “interdependent parts of a larger 

action and depend on the larger action for their justification.” 

Id. § 1508.25(a)(1). And actions are “similar” if, “when 

viewed with other reasonably foreseeable or proposed agency 

actions, [they] have similarities that provide a basis for 

evaluating their environmental consequences together, such as 

common timing or geography.” Id. § 1508.25(a)(3).

NEPA is “essentially procedural,” designed to ensure 

“fully informed and well-considered decision[s]” by federal 

agencies. Vt. Yankee Nuclear Power Corp. v. NRDC, 435 U.S. 

519, 558 (1978). “‘NEPA itself does not mandate particular 

results’ in order to accomplish [its] ends. Rather, NEPA 

imposes only procedural requirements on federal agencies 

with a particular focus on requiring agencies to undertake 

analyses of the environmental impact of their proposals and 

actions.” Dep’t of Transp. v. Pub. Citizen, 541 U.S. 752, 756-

57 (2004) (quoting Robertson v. Methow Valley Citizens 

Council, 490 U.S. 332, 350 (1989)). “The procedures required 

by NEPA . . . are designed to secure the accomplishment of 

the vital purpose of NEPA. That result can be achieved only if 

the prescribed procedures are faithfully followed . . . .” 

Lathan v. Brinegar, 506 F.2d 677, 693 (9th Cir. 1974). In 

preparing an EA or EIS, an “agency need not foresee the 

unforeseeable, but . . . [r]easonable forecasting and 

speculation is . . . implicit in NEPA, and we must reject any 

attempt by agencies to shirk their responsibilities under NEPA 

by labeling any and all discussion of future environmental 

effects as ‘crystal ball inquiry.’” Scientists’ Inst. for Pub. 

Info., Inc. v. Atomic Energy Comm’n, 481 F.2d 1079, 1092 

(D.C. Cir. 1973). While the statute does not demand 

forecasting that is “not meaningfully possible,” an agency 

must fulfill its duties to “the fullest extent possible.” Id.
9

B. Factual and Procedural History

Both the Eastern and Western Legs of the 300 Line were 

initially constructed with 24-inch pipe. To accommodate 

increased production and demand in the natural gas market, 

however, Tennessee Gas embarked on upgrades installing 

what is known as “looped” pipeline. In a looped structure, the 

old pipeline is left in place, while a larger pipeline is installed 

in parallel, connecting to the old pipe so that the two lines 

function as one system. As the overall system structure 

expands, each additional length of 30-inch pipe or 

compression horsepower results in increasing returns to the 

pipeline’s capacity. For example, the first upgrade to the 

Eastern Leg (which commenced in 2010 and was completed 

in 2011) resulted in the installation of approximately 130

miles of new 30-inch pipe and added 350,000 dekatherms per 

day to the pipeline’s capacity (with each dekatherm roughly 

equivalent to 1,000 cubic feet of gas). The Northeast Upgrade,

in comparison, added only 40 miles of new pipe but added 

636,000 dekatherms per day to the system. Abbreviated Appl.

of Tenn. Gas Pipeline Co. for a Certificate of Public 

Convenience and Necessity at 2 n.1, 4, reprinted in Joint 

Appendix (“J.A.”) 188, 190 ( “Application”); Br. of Resp’t at 

21.

Between 2010 and 2013, Tennessee Gas commenced four 

upgrade projects along the Eastern Leg. In chronological 

order, they are: (1) the 300 Line Project; (2) the Northeast

Supply Diversification Project; (3) the Northeast Project; and

(4) the MPP Project. In May 2010, FERC certified the 300 

Line Project, which placed eight sections of 30-inch pipeline 

along the Eastern Leg of the 300 Line, and upgraded various 

facilities and compressor stations along the entire line. The 

new pipe segments were also looped, or connected, to the 
10

existing 24-inch pipeline, and covered approximately 130 

miles of the Eastern Leg, leaving seven sections of the 

pipeline with only the decades-old 24-inch pipe. 

As construction of the 300 Line Project was underway, 

Tennessee Gas initiated the three additional projects

mentioned above to fill in the gaps that would be left by the 

300 Line Project. Specifically, in November 2010, the 

company applied for certification of the Northeast Supply 

Diversification Project to add a 6.8-mile segment to the 

pipeline, connecting two of the 300 Line Project sections; in 

March 2011, it applied for certification of the Northeast 

Project to add five segments (40 miles in total) of new 

pipeline as well as compression upgrades and various 

infrastructure improvements; and in December 2011, four 

months after soliciting contracts for the project, it applied for 

certification of the MPP Project, which would cover the only 

remaining 7.9-mile segment that was still served solely by 24-

inch pipe. In November 2011, the company completed 

construction on the 300 Line Project.

As each of the four projects was planned, the expected

increased capacity on the 300 Line (measured in dekatherms 

per day) was contracted to natural gas shippers through a 

binding open season bidding process. See, e.g., Application at 

10, reprinted in J.A. 196. All of the gas transported through 

the Eastern Leg, however, uses all of the now-complete 

sections from the four projects, passing from one segment to 

the next on its way to the pipeline’s delivery point in New 

Jersey. In other words, even though each project’s 

incremental increase in pipeline capacity was contracted for 

separately, all of the projects function together seamlessly.

The 24-inch pipeline is buried underground in a corridor 

that is maintained and kept accessible by keeping major tree 
11

growth cleared. In general, the new 30-inch pipe was added 

by widening the original corridor by 25 feet, clearing and 

grading this strip, blasting or digging a trench, installing the 

pipe in the trench, covering the pipe, and then restoring the 

vegetation. As new segments of pipe were added, they were 

connected to the old pipe, to adjacent sections of new pipe, 

and to the compressor stations between the sections.

In its challenge to the Northeast Project, Riverkeeper is 

concerned with habitat fragmentation, hydrology impacts to 

wetlands and groundwater, and “edge effects” of 

deforestation. See Br. of Pet’rs at 29, 37, 42-43. Riverkeeper 

claims that the Northeast Project alone cleared 265 acres of 

forest and impacted 50 acres of wetlands, and that the four 

projects together permanently deforested 628 acres. Id. at 4.

Riverkeeper and other commenters raised these concerns 

before the Commission. 

In July 2010, Tennessee Gas invoked FERC’s pre-filing 

process for the Northeast Project, and in October 2010 the 

agency issued a Notice of Intent to prepare an EA. Petitioners 

submitted comments on the Notice of Intent in November

2010, arguing, inter alia, that

[i]t is clear that the 300 Line Project and the Project at 

issue here are all part of a larger development plan, as 

they involve interlocking loop upgrades of the same 

pipeline. [Tennessee Gas] must not be allowed to 

circumvent heightened environmental scrutiny by 

segmenting their upgrades in such a way. The cumulative 

consequences of all these projects, many of them 

previously subject to FERC approval, must be assessed 

in the NEPA document.
12

Response to Notice of Intent to Prepare Environmental 

Assessment on Behalf of Delaware Riverkeeper et al., Nov. 

12, 2010 at 13, reprinted in J.A. 162; see also Pa. Dep’t of 

Conservation & Natural Res. Comments on Notice of Intent, 

Nov. 23, 2010 at 7, reprinted in J.A. 184 (noting that the 

Bureau of Forestry “previously urged FERC to evaluate the 

entire corridor parallel to the existing . . . line”).

On March 31, 2011, Tennessee Gas submitted its 

certificate application for the Northeast Project. Application, 

reprinted in J.A. 186. On November 21, 2011, FERC issued 

an EA that recommended a Finding of No Significant Impact. 

Northeast Upgrade Project Environmental Assessment at 4-1, 

reprinted in J.A. 580 (“Northeast Project EA”). Petitioners

and other interested parties intervened and submitted timely 

comments. These comments reiterated the concern that the 

Project’s NEPA analysis was improperly segmented and 

deficient in its cumulative impacts inquiry:

Remarkably, the EA fails to assess the additive effect of 

the Project together with the effects of existing or 

reasonably foreseeable gas development activities in the 

Project area, including . . . compressor stations, and other 

infrastructure. . . . 

The EA is likewise inadequate in considering the 

combined environmental impacts of related existing and 

reasonably foreseeable pipelines within the 

Commission’s Jurisdiction. The EA identifies ten 

existing or proposed pipelines within fifty miles of the 

Project area, totaling at least 240 miles of new or 

improved pipeline construction. EA at 2-123-124. Five of 

these projects will either connect or be adjacent to the 

Project. EA at 2-126. However, the EA provides 

absolutely no detailed information or analysis relating to 
13

the additive environmental impacts of these past, present, 

and proposed actions.

Comments on Environmental Assessment at 13, 17, reprinted 

in J.A. 699, 703; see also Hay & Newman Comments, Aug. 

25, 2011 at 2, reprinted in J.A. 390 (“The fact that the ‘300 

Line’ gas pipeline project was approved by FERC the same 

year of the submission of the subject application raises 

concerns of impermissible segmentation. It seems unlikely the 

approved . . . projects are not related segments to a broader 

phased development plan. . . .”); Pike Cnty. Conservation 

Dist. Comments, Dec. 20, 2011 at 3, reprinted in J.A. 746

(raising the same concerns).

On May 29, 2012, FERC issued the Order including a 

Finding of No Significant Impact and certificate approval for 

the Northeast Project. Order, 2012 WL 1934728, at *1, *11. 

On June 28, 2012, Petitioners submitted a request for 

rehearing. Petitioners claimed that:

The Commission violated NEPA by granting the 

Certificate for construction of the [Northeast Project]

without properly applying the NEPA regulations in 

evaluating the significance of the Project’s impacts, 

without ensuring an adequate review of the Project’s 

cumulative impacts, and without ensuring that necessary 

mitigation measures would be fully implemented and 

complied with to minimize and avoid significant negative 

environmental impacts. Moreover, the Commission 

violated NEPA by unlawfully segmenting consideration 

of the [Northeast Project’s] impacts from other 

interdependent and inter-related projects on the Eastern 

Leg of the 300 Line.

Request for Reh’g at 3-4, reprinted in J.A. 837-38. 
14

FERC denied this request for rehearing. It reiterated the 

position it took in the May 29 Order, stating that it “found that 

each project is a stand-alone project and designed to provide 

contracted-for volumes of gas to different customers within 

different timeframes.” Tenn. Gas Pipeline Co., 142 FERC 

¶ 61,025, 2013 WL 240878, at *10 (Jan. 11, 2013) (“Reh’g 

Order”). Petitioners timely filed the instant petition for review 

in this court.

II. ANALYSIS

A. Standard of Review

Judicial review of agency actions under NEPA is 

available “to ensure that the agency has adequately considered 

and disclosed the environmental impact of its actions and that 

its decision is not arbitrary or capricious.” Baltimore Gas & 

Elec. Co. v. NRDC, 462 U.S. 87, 97–98 (1983); see also Nat’l 

Comm. for the New River, Inc. v. FERC, 373 F.3d 1323, 1327 

(D.C. Cir. 2004). Courts may not use their review of an 

agency’s environmental analysis to second-guess substantive 

decisions committed to the discretion of the agency. Where an 

issue “requires a high level of technical expertise,” we “defer 

to the informed discretion of the [Commission].” Marsh v. Or. 

Natural Res. Council, 490 U.S. 360, 377 (1989) (internal 

quotation marks omitted). 

Although the standard of review is deferential, we have 

made it clear that “[s]imple, conclusory statements of ‘no 

impact’ are not enough to fulfill an agency’s duty under 

NEPA.” Found. on Econ. Trends v. Heckler, 756 F.2d 143, 

154 (D.C. Cir. 1985). The agency must comply with 

“principles of reasoned decisionmaking, NEPA’s policy of 

public scrutiny, and [the Council on Environmental Quality’s] 
15

regulations.” Id. at 154 (citations omitted). And under the 

applicable arbitrary and capricious standard of review,

the agency must examine the relevant data and articulate 

a satisfactory explanation for its action including a 

rational connection between the facts found and the 

choice made. In reviewing that explanation, we must 

consider whether the decision was based on a 

consideration of the relevant factors and whether there 

has been a clear error of judgment. Normally, an agency 

rule would be arbitrary and capricious if the agency has 

relied on factors which Congress has not intended it to 

consider, entirely failed to consider an important aspect 

of the problem, offered an explanation for its decision 

that runs counter to the evidence before the agency, or is 

so implausible that it could not be ascribed to a 

difference in view or the product of agency expertise. 

The reviewing court should not attempt itself to make up 

for such deficiencies: We may not supply a reasoned 

basis for the agency’s action that the agency itself has not 

given.

Motor Vehicle Mfrs. Ass’n of the U.S., Inc. v. State Farm Mut.

Auto. Ins., 463 U.S. 29, 43 (1983) (internal quotation marks 

and citations omitted). In sum, an agency action will be set 

aside as arbitrary and capricious if it is not the product of 

“reasoned decisionmaking.” Id. at 52.

B. Segmentation

An agency impermissibly “segments” NEPA review 

when it divides connected, cumulative, or similar federal 

actions into separate projects and thereby fails to address the 

true scope and impact of the activities that should be under 

consideration. The Supreme Court has held that, under NEPA, 
16

“proposals for . . . actions that will have cumulative or 

synergistic environmental impact upon a region . . . pending 

concurrently before an agency . . . must be considered 

together. Only through comprehensive consideration of 

pending proposals can the agency evaluate different courses 

of action.” Kleppe v. Sierra Club, 427 U.S. 390, 410 (1976). 

Regulations promulgated by the Council on 

Environmental Quality in 1978 dictate the appropriate scope 

of a NEPA document. The regulations state, in relevant part, 

that:

To determine the scope of environmental impact 

statements, agencies shall consider 3 types of actions

. . . . They include:

(a) Actions (other than unconnected single actions) which 

may be:

(1) Connected actions, which means that they are 

closely related and therefore should be discussed 

in the same impact statement. Actions are 

connected if they: 

* * * 

(iii) Are interdependent parts of a larger action 

and depend on the larger action for their 

justification. 

(2) Cumulative actions, which when viewed with 

other proposed actions have cumulatively 

significant impacts and should therefore be 

discussed in the same impact statement. 

(3) Similar actions, which when viewed with other 

reasonably foreseeable or proposed agency 

actions, have similarities that provide a basis for 

evaluating their environmental consequences 
17

together, such as common timing or 

geography. . . . 

40 C.F.R. § 1508.25.

The justification for the rule against segmentation is 

obvious: it “prevent[s] agencies from dividing one project into 

multiple individual actions each of which individually has an 

insignificant environmental impact, but which collectively 

have a substantial impact.” NRDC v. Hodel, 865 F.2d 288, 

297 (D.C. Cir. 1988) (internal quotation marks omitted).

NEPA is, “in large measure, an attempt by Congress to instill 

in the environmental decisionmaking process a more 

comprehensive approach so that long term and cumulative 

effects of small and unrelated decisions could be recognized, 

evaluated and either avoided, mitigated, or accepted as the 

price to be paid for the major federal action under 

consideration.” NRDC v. Callaway, 524 F.2d 79, 88 (2d Cir. 

1975). 

Thus, when determining the contents of an EA or an EIS, 

an agency must consider all “connected actions,” “cumulative 

actions,” and “similar actions.” 40 C.F.R. § 1508.25(a); see

also, e.g., Am. Bird Conservancy, Inc. v. FCC, 516 F.3d 1027, 

1032 (D.C. Cir. 2008) (reviewing the agency’s application of 

the regulations in its preparation of an EA); Allison v. Dep’t of 

Transp., 908 F.2d 1024, 1031 (D.C. Cir. 1990) (reviewing the 

agency’s application of the regulations in its preparation of an 

EIS). As noted above, in their claims before FERC, 

Petitioners and other commenters argued that, in the NEPA 

review of the Northeast Project, FERC was obliged to 

consider the impacts from other connected actions on the 

Eastern Leg of the 300 Line, and to assess the cumulatively 

significant impacts of the four closely related and interrelated 

projects. In our view, these claims are meritorious.
18

The disputed Northeast Project was the third of the four 

pipeline construction projects completed in quick succession 

on the Eastern Leg of the 300 Line. As noted above, when 

FERC issued the certificate for the Northeast Project, it was 

clear that the entire Eastern Leg was included in a complete 

overhaul and upgrade. During the course of FERC’s review of 

the Northeast Project application, the other three upgrade 

projects were either under construction (as with the 300 Line 

Project) or were also pending before FERC for environmental 

review and approval (as with the Northeast Supply 

Diversification Project and the MPP Project). The end result 

is a single pipeline running from the beginning to the end of 

the Eastern Leg. The Northeast Project is, thus, indisputably 

related and significantly “connected” to the other three 

pipeline upgrade projects. 

It is noteworthy that FERC does not at all address the 

requirements of 40 C.F.R. § 1508.25(a)(1) or § 1508.25(a)(3) 

in defending its determination that the four projects should be 

treated separately. Indeed, FERC never even cites the 

applicable regulations which form the basis of Petitioners’ 

claims in this case. See Br. of Resp’t at ix (nowhere citing 40 

C.F.R. § 1508.25). Instead, FERC relies on the four factors 

we announced in Taxpayers Watchdog v. Stanley, 819 F.2d 

294 (D.C. Cir. 1987), to argue that it did not impermissibly 

“segment” its NEPA analysis. But as we made clear in 

Coalition on Sensible Transportation, Inc. v. Dole, 826 F.2d 

60, 68 (D.C. Cir. 1987), an agency’s consideration of the 

proper scope of its NEPA analysis should be guided by the 

governing regulations. There, we stated that “[i]n considering 

the proper scope of the . . . project, the district court quite 

properly referred to Federal Highway Administration 

regulations.” Id. We then quoted the agency-specific scoping 

regulations that govern in the context of a federal highway 
19

project. Id. (quoting 23 C.F.R. § 771.111(f)). We then 

remarked that Taxpayers Watchdog relied on “the same or 

closely similar factors.” Id. But even if the analyses were 

closely related, the point remains: the agency’s determination 

of the proper scope of its environmental review must train on 

the governing regulations, which here means 40 C.F.R. 

§ 1508.25(a). In any event, as we explain below, FERC’s 

position fails even on its own terms.

In Taxpayers Watchdog we stated that “[t]he rule against 

segmentation . . . is not required to be applied in every 

situation.” 819 F.2d at 298. It is possible, in some 

circumstances, for an agency to determine that physically 

connected projects can be analyzed separately under NEPA.

Taxpayers Watchdog, for example, involved a NEPA review 

of a subway construction project in which plans for a large 

project were abandoned in favor of a shorter length of rail. 

The court explained that the new plans could be properly 

analyzed without regard to potential further development

because the shorter segment “(1) has logical termini; (2) has 

substantial independent utility; (3) does not foreclose the 

opportunity to consider alternatives; and (4) does not 

irretrievably commit federal funds for closely related 

projects.” Id. The first two factors cited in Taxpayers 

Watchdog are relevant in this case.

Logical Termini

FERC has not articulated any viable reason why it 

completed its NEPA review of the Northeast Project without 

regard to the other three projects on the Eastern Leg of the 

300 Line. The agency does not contend that the four projects 

were properly divided pursuant to some “logical termini,” or 

rational end points. Rather, FERC simply asserts – in its brief 

to this court, not in the agency action under review – that its 
20

choice is not arbitrary and capricious if “one terminus is no 

more logical than another.” Br. of Resp’t at 25. This will not 

do. Under this line of reasoning, FERC could have certified 

pipeline construction in one-mile sections, or hundred-yard 

sections, or one-foot sections. 

FERC relies on a NEPA case that addressed highway 

construction, Coalition for Sensible Transp., 826 F.2d 60. But 

that case lends little support to the agency’s position.

Coalition for Sensible Transportation concerned a road 

construction project in Montgomery County, Maryland. Id. at 

62. The project was intended to widen approximately sixteen 

miles of Interstate 270 and modify five interchanges along the 

way. “The stretch of I-270 at issue runs north from the Spur 

connecting I-270 to I-495 (the Washington Beltway). It is a 

heavily travelled route for traffic entering and leaving the 

District of Columbia and also for local traffic between and 

within the various nearby towns.” Id. The opinion noted that 

“in the context of a highway within a single metropolitan area 

– as opposed to projects joining major cities – the ‘logical 

terminus’ criterion is unusually elusive. . . . Fully 45 percent 

of the traffic now using the road neither originates nor 

terminates at the Beltway. Thus the Beltway is no more 

logical as a terminus than the Spur.” Id. at 69. To the extent 

that the Eastern Leg pipeline is comparable to a highway, it is 

more analogous to a highway that connects two major points 

than one section of a web of metropolitan roadways for which 

the logical termini criterion loses significance.

In rejecting the appellants’ claims in Coalition for

Sensible Transportation, the court also noted that “it is 

inherent in the very concept of a highway network that each 

segment will facilitate movement in many others; if such 

mutual benefits compelled aggregation, no project could be 

said to enjoy independent utility.” Id. The same cannot be said 
21

about a single pipeline on which each newly constructed part 

facilitates service only within the bounds of the same start and 

end points. There are no spurs, interchanges, or corridors 

connected to the Eastern Leg. There is a single pipeline 

running from the beginning to the end of the Eastern Leg. The 

pipeline is linear and physically interdependent, and it 

contains no physical offshoots. In sum, Coalition for Sensible 

Transportation is inapposite.

Substantial Independent Utility

FERC has also failed to show that the Northeast Project 

had substantial independent utility separate from the other 

three pipeline renovation projects on the Eastern Leg of the 

300 Line. Tennessee Gas and FERC contend that the 

Northeast Project has independent utility because the 

company secured new shipping contracts in anticipation of the 

increased capacity that would come with the completion of 

the project. Br. of Resp’t at 20-24; Br. of Intervenors at 10-12. 

This argument is unpersuasive. 

First, FERC has a “threshold requirement” for pipelines 

proposing new projects: the “pipeline must be prepared to 

support the project financially without relying on 

subsidization from existing customers.” Order, 2012 WL 

1934728, at *4. As a result of this policy, Tennessee Gas was 

required to contract for increased capacity prior to upgrading 

the Eastern Leg of the pipeline. The commercial and financial 

viability of a project when considered in isolation from other 

actions is potentially an important consideration in 

determining whether the substantial independent utility factor 

has been met. FERC’s reliance on the shipping contracts in 

this case, however, is insufficient because the contracts do not 

show that the Northeast Project was driven by independent 

financial considerations apart from the other projects.
22

Indeed, it is clear from FERC’s Order that the upgrade 

projects on the Eastern Leg are financially interdependent. 

The Order states: 

Tennessee calculated this [Northeast Project capacity] 

rate using the costs and design capacities of both the 

proposed Northeast Upgrade Project and the . . . 300 Line 

Project. . . . The 300 Line Project makes it possible for 

Tennessee to achieve the capacity increase of the 

Northeast Upgrade Project at a much lower cost than 

would have been possible absent construction of the 300 

Line Project Market Component facilities.

Id. at *2.

It is also noteworthy that Tennessee Gas sought an 

“exception” to the normal policy of “incremental pricing for 

all projects” in its Northeast Project application. FERC 

explained this in its Order:

Tennessee maintains the inexpensive expansibility of the 

Northeast Upgrade Project facilities is a result of the 

earlier, more expensive capacity created by the 300 Line 

Project . . . . Although Tennessee is not proposing to roll 

the Northeast Upgrade Project costs into its general 

system rates, Tennessee contends its proposal to roll the 

project’s costs into the rates of the 300 Line Project . . . is 

consistent with the premise that such rolled-in rate 

treatment is appropriate in cases of inexpensive 

expansibility made possible because of earlier costly 

construction.

Tennessee further notes that in the precedent 

agreement that provided the market support for the 300 
23

Line Project, Tennessee and EQT Energy, LLC agreed to 

a rate adjustment to the negotiated rate “to the extent a 

subsequent project meeting certain criteria would be 

constructed and eventually placed in-service within a 

specified time period.” Tennessee also explains that the 

parties agreed to this negotiated rate adjustment in 

recognition that Tennessee would likely be able to 

construct a subsequent project (such as the Northeast 

Upgrade Project) at a lower cost than would have been 

possible without the 300 Line Project.

Id. at *6. Not only did Tennessee Gas acknowledge the 

functional interdependence of the 300 Line Project and the 

Northeast Project, it made clear that the projects are 

financially interdependent as well. Indeed, Tennessee Gas’s 

prior agreement with EQT Energy was made in express 

contemplation of the synergies to be obtained between the 

300 Line and the Northeast Project. Even if the Northeast 

Project has utility, it is plainly not independent utility.

FERC’s argument in this case that the “substantial 

independent utility” standard is satisfied when an individual 

project is “completed and in-service” and “meets specific 

customer demand,” Br. of Resp’t at 21, proves too much. 

Under this approach, Tennessee Gas could have proposed 

two-mile segments, or one-mile segments, or one-hundredyard segments for NEPA review, so long as it produced 

shipping contracts in anticipation of the increased capacity 

attributable to each of these new segments. To interpret the 

“substantial independent utility” factor to allow such 

fractionalization of interdependent projects would subvert the 

whole point of the rule against segmentation. 

The “specific customer demand” argument relied on by 

FERC paints a false picture. In truth, what happened is that 
24

Tennessee Gas had to justify its applications for pipeline 

upgrades by showing that there would be customers to 

purchase the increased gas volume that would come as a 

result of an upgrade. There are no “Northeast Project 

customers” as such. Gas does not enter and exit the pipeline 

between segments on the Eastern Leg of the 300 Line. See 

Application at 1, 15, reprinted in J.A. 187, 201; Tennessee 

Gas Pipeline Environmental Report at 10-5, reprinted in J.A. 

329. And customers do not take gas from the Northeast 

Project portion of the Eastern Leg. In this respect, the 

Northeast Project portion of the pipeline is not the equivalent

of a highway spur, interchange, or corridor that has utility 

independent of another highway to which it connects. The 

Northeast Project’s utility is inextricably intertwined with the 

other three improvement projects that, together, upgrade the 

entire Eastern Leg of the 300 Line.

Project Timing

FERC also argues that the timing of the project 

applications defeats Petitioners’ segmentation claim because 

NEPA analyses should not cover projects already completed 

or not yet proposed. Br. of Resp’t at 26. NEPA, of course,

does not require agencies to commence NEPA reviews of 

projects not actually proposed. E.g., Weinberger v. Catholic 

Action of Haw., 454 U.S. 139, 146 (1981). While 

Riverkeeper’s challenge is limited to FERC’s NEPA review 

of the Northeast Project, this challenge includes the question 

whether FERC was obliged to take into account the other 

“connected” or “similar” projects on the Eastern Leg when it 

conducted the NEPA review for the Northeast Project.

The temporal nexus here is clear. Tennessee Gas 

proposed the Northeast Project while the 300 Line Project 

was under construction, and FERC plainly was aware of the 
25

physical, functional, and financial links between the two 

projects. And FERC’s consideration of the Northeast Project 

application overlapped with its consideration of the remaining 

two projects. Indeed, FERC’s review of the Northeast Project 

overlapped with its review of the Northeast Supply 

Diversification Project for the first six months and with the 

MPP Project’s review for the final six months. Thus, FERC 

was obliged to take into account the condition of the 

environment reflected in the recently related and connected 

upgrades. The adjacent lands were recently disturbed, wildlife 

faced a larger habitat disruption, there was an increase in 

pressure and gas moving through the system, and wetlands 

and groundwater flow was disrupted. These effects could not 

be ignored in FERC’s NEPA review of the Northeast Project. 

Tennessee Gas states that it did not know at the time it 

commenced the 300 Line Project that it was embarking on a 

series of upgrade projects that would soon transform the 

entire pipeline. That may be so. But the important question 

here is whether FERC was justified in rejecting commenters’ 

requests that it analyze the entire pipeline upgrade project 

once the Northeast Project was under review and once the 

parties had pointed out the interrelatedness of the sequential 

pieces of pipeline which were, in fact, creating a complete, 

new, linear pipeline. Because of the temporal overlap of the 

projects, the scope and interrelatedness of the work should 

have been evident to FERC as it reviewed the Northeast 

Project. Yet FERC wrote and relied upon an EA that failed to 

consider fully the contemporaneous, connected projects.

We emphasize here the importance we place on the

timing of the four improvement projects. Separated by more 

time, the projects could have utility independent of the other 

projects. That is, the indications of the financial and 

functional interdependence of the projects might have been 
26

subsumed by the fact that Tennessee Gas constructed each 

project to be a standalone improvement for a substantial 

period of time. To take an obvious example, if the 300 Line 

Project had been placed into service a decade before FERC 

considered the Northeast Project application, the timing of the 

projects would support, rather than undermine, the conclusion 

that the projects had utility independent of each other. Here, 

however, the timing does not support the independence of the 

projects; rather, we are left with the fact that financially and 

functionally interdependent pipeline improvements were 

considered separately even though the there was no apparent 

logic to where one project began and the other ended. 

* * *

For the reasons explained above, we find that FERC’s 

NEPA review of the Northeast Project violated the 

segmentation rule. When FERC was reviewing the Northeast 

Project application, it was undeniably aware that the previous 

and following projects were also under construction or 

review, and that each phase of the development fit with the 

others like puzzle pieces to complete an entirely new pipeline. 

FERC has suggested that the Petitioners should have 

anticipated the future upgrades and raised their concerns 

during FERC’s NEPA review of the 300 Line Project. This 

argument rings hollow in light of Tennessee Gas’s and 

FERC’s assertions that they did not know of the future 

upgrades when FERC initially reviewed the 300 Line Project. 

Petitioners raised their objections to FERC’s segmented 

analysis of the connected projects once it became clear that 

there were going to be four connected and interrelated 

upgrade projects on the Eastern Leg of the 300 Line. When

the connections and interdependencies became clear and were 
27

brought to FERC’s attention, the agency was obliged to assess 

the entire pipeline for environment effects. 

On the record before us, we find that FERC acted 

arbitrarily in deciding to evaluate the environmental effects of 

the Northeast Project independent of the other connected 

actions on the Eastern Leg. There were clear indications in the 

record that the improvement projects were functionally and 

financially interdependent, and the absence of logical termini 

suggests that the four projects functioned as one unified 

upgrade of the Eastern Leg. And the temporal overlap serves 

to reinforce this conclusion. 

C. Cumulative Impacts

Many of the same points that support Riverkeeper’s 

segmentation claim also sustain its contention that FERC’s 

EA is deficient in its failure to include any meaningful 

analysis of the cumulative impacts of Tennessee Gas’s 

projects.

Cumulative effects are defined by the Council on 

Environmental Quality as “the impact on the environment 

which results from the incremental impact of the action when 

added to other past, present, and reasonably foreseeable future 

actions regardless of what agency (Federal or non-Federal) or 

person undertakes such other actions. Cumulative impacts can 

result from individually minor but collectively significant 

actions taking place over a period of time.” 40 C.F.R. § 

1508.7. We have explained that “a meaningful cumulative 

impact analysis must identify (1) the area in which the effects 

of the proposed project will be felt; (2) the impacts that are 

expected in that area from the proposed project; (3) other 

actions – past, present, and proposed, and reasonably 

foreseeable – that have had or are expected to have impacts in 
28

the same area; (4) the impacts or expected impacts from these 

other actions; and (5) the overall impact that can be expected 

if the individual impacts are allowed to accumulate.” Grand 

Canyon Trust v. FAA, 290 F.3d 339, 345 (D.C. Cir. 2002).

The three Eastern Leg upgrade projects preceding and 

following the Northeast Project were clearly “other actions –

past, present, and proposed, and reasonably foreseeable.” Id.

FERC’s Order approving the Northeast Project 

acknowledges that commenters requested that the agency 

consider the other upgrade projects on the Eastern Leg and the 

cumulative impacts of the projects viewed together. Order, 

2012 WL 1934728, at *49. In response, FERC summarily 

stated that the construction impacts “were temporary,” and 

“separated by time and distance” from the Northeast Project. 

Id. As we have explained, the record simply does not support 

this conclusion. 

FERC’s EA for the Northeast Project states, in 

conclusory terms, that the connected pipeline projects were 

“not expected to significantly contribute to cumulative 

impacts in the Project area.” Northeast Project EA at 2-127, 

reprinted in J.A. 557. This cursory statement does not satisfy 

the test enunciated in Grand Canyon Trust. The EA also 

contains a few pages that discuss potential cumulative impacts 

on groundwater, habitat, soils, and wildlife, but only with 

respect to the Northeast Project. It is apparent that FERC did 

not draft these pages with any serious consideration of the 

cumulative effects of the other project upgrades on the 

Eastern Leg of the 300 Line. In light of the close connection 

between the various sections of the line that have been 

upgraded with new pipe and other infrastructure 

improvements, FERC was obliged to assess cumulative 

impacts by analyzing the Northeast Project in conjunction 

with the other three projects.
29

III. CONCLUSION

For the foregoing reasons, we grant the petition for 

review insofar as it challenges FERC’s segmentation of its 

NEPA review of the Northeast Project, and its failure to 

adequately address the cumulative impacts of the four 

upgrade projects on the Eastern leg of the 300 Line. We 

hereby remand the case to FERC for further consideration of 

these two issues.
BROWN, Circuit Judge, concurring in part and concurring 

in the judgment: I join Part II.C of the majority opinion, 

granting the petition for FERC’s failure to adequately address 

the cumulative impacts of the four upgrade projects. As I see 

it, the practical effect of the Court’s segmentation holding—

now that several of the projects are complete—can only be 

FERC’s need for a more thorough cumulative impacts 

analysis. Therefore, I would have focused on that aspect of 

Petitioners’ wide-ranging and evolving challenges, and I 

would have declined to delve into the murky waters of 

backwards-looking segmentation review, especially since 

improper segmentation was raised only at the end of the 

lengthy approval process and scarce case law is available 

concerning gas pipelines, which, as the majority also explains, 

are distinct from highways and railways. 

Nevertheless, I agree with the majority that “[m]any of 

the same points [from] Riverkeeper’s segmentation claim . . . 

sustain its contention that FERC’s EA is deficient in its failure 

to include any meaningful analysis of the cumulative impacts 

of Tennessee Gas’s projects.” Maj. Op. at 27. The close 

timing, functional interdependence, and physical 

connectedness of the four upgrade projects inform the need 

for FERC to address the cumulative impacts of the other 

projects within the Northeast Project’s EA. Here, FERC 

utterly failed to explain why timing and distance—factors that 

actually show the connectedness of the projects—justify

excluding the other upgrade projects from the cumulative 

impacts analysis. See J.A. 554–57 (excluding consideration 

of the Northeast Supply Project because it was “at least 25 

miles from” the Northeast Upgrade Project). For this reason, 

I would grant the petition and remand the case to FERC for 

further consideration of the appropriate cumulative impacts. 
SILBERMAN, Senior Circuit Judge, concurring: I join Judge

Edwards’ opinion because of the emphasis he puts on the timing

of these different projects, but I do think Judge Brown has a

good point in suggesting that the “cumulative impact” issue is

a stronger ground upon which to base the decision. 

* * * 

Petitioner’s brief, unfortunately, was laden with obscure

acronyms notwithstanding the admonitions in our handbook

(and on our website) to avoid uncommon acronyms. Since the

brief was signed by a faculty member at Columbia Law School,

that was rather dismaying both because of ignorance of our

standards and because the practice constitutes lousy brief

writing. 

The use of obscure acronyms, sometimes those made up for

a particular case, is an aggravating development of the last

twenty years. Even with a glossary, a judge finds himself or

herself constantly looking back to recall what an acronym

means. Perhaps not surprisingly, we never see that in a brief

filed by well-skilled appellate specialists. It has been almost a

marker, dividing the better lawyers from the rest.

We have recently been rejecting briefs that do not adhere to

our instructions, and counsel should be warned that if a brief is

rejected and has to be rewritten, they will not be able to alter the

word limits.