ES-1 Executive Summary

EXECUTIVE SUMMARY

The staff of the Federal Energy Regulatory Commission (FERC or Commission) has prepared 

this final Environmental Impact Statement (EIS) to fulfill requirements of the National Environmental 

Policy Act of 1969 (NEPA) and the Commission’s implementing regulations under Title 18 of the Code 

of Federal Regulations Part 380 (18 CFR 380). On February 7 and 8, 2013, Sierrita Gas Pipeline LLC 

(Sierrita) filed applications with the Commission pursuant to sections 3 and 7 of the Natural Gas Act 

(NGA) and Parts 153, 157, and 284 of the Commission’s regulations for: 1) authorization to construct and 

operate facilities necessary for the exportation of natural gas, a Presidential Permit to allow construction 

of facilities at the U.S.-Mexico border, and a Blanket Certificate for limited future activities and services; 

and 2) a Certificate of Public Convenience and Necessity (Certificate) to construct, operate, and maintain 

a natural gas pipeline and associated ancillary and aboveground facilities, collectively known as the 

Sierrita Pipeline Project (Project). The purpose of this document is to inform the public and the 

permitting agencies about the potential adverse and beneficial environmental impacts of the Project and 

its alternatives, and to recommend mitigation measures that would avoid or reduce adverse impacts. 

The FERC is the federal agency responsible for authorizing interstate natural gas transmission 

facilities under the NGA, and is the lead federal agency for the preparation of this EIS in compliance with 

the requirements of NEPA. The U.S. Fish and Wildlife Service (FWS) – Arizona Ecological Services 

Office, the FWS – Buenos Aires National Wildlife Refuge (BANWR), the Arizona Game and Fish 

Department, and the U.S. Customs and Border Protection (CBP) are cooperating agencies for the 

development of this EIS. A cooperating agency has jurisdiction by law or has special expertise with 

respect to environmental resource issues associated with a project. The U.S. Border Patrol, the law 

enforcement arm of the CBP, has been working closely with us1in drafting the border-related components 

of the EIS.

PROPOSED ACTION

The purpose of the Project is to transport 200,846 dekatherms per day (Dth/d) of natural gas from 

a tie-in with El Paso Natural Gas Company’s (EPNG) existing South Mainline System at milepost (MP) 

0.0 near Tucson, Arizona south to MP 59.12 on the U.S.-Mexico border near the Town of Sasabe, 

Arizona. At the border, the pipeline would interconnect with the Sásabe-Guaymas Pipeline in Mexico, 

which is proposed to be constructed, owned, and operated by IENova, an affiliate of Sempra Energy. In 

Mexico, the 338-mile-long Sásabe-Guaymas Pipeline would extend from the U.S.-Mexico border near El 

Sásabe, Mexico to electric generation facilities near the Cities of Puerto Libertad and Guaymas, Mexico. 

Mexico is proposing to convert or replace fuel oil thermal generation plants into natural gas-fired 

combined-cycle generation plants. The Sásabe-Guaymas Pipeline, in conjunction with the Project, would 

provide both natural gas and pipeline infrastructure to deliver gas for this purpose. 

Dependent upon Commission approval, Sierrita would seek approval to begin construction as 

soon as possible after receiving all necessary federal authorizations and meeting any and all preconstruction environmental conditions. Sierrita proposes to place the facilities into operation on or about 

the end of September 2014. Sierrita proposes to construct and operate: 

 

1

“We,” “us,” and “our” refer to the environmental staff of the Federal Energy Regulatory Commission’s Office of 

Energy Projects.

2 The pipeline route ends at MP 59.1. However, due to a route modification adopted by Sierrita in March 2013 

between MPs 25.7 and 36.3, and a route modification adopted by Sierrita subsequent to the draft EIS between 

MPs R35.2 and R36.4, an additional 1.8 miles of pipeline was added to the Project, resulting in a total pipeline 

length of 60.9 miles. 
Executive Summary ES-2

 60.9 miles of 36-inch-diameter natural gas transmission pipeline in Pima County, 

Arizona;

 two new meter stations;

3

 six mainline valves (MLVs);

4

and 

 two pig launcher and two pig receiver facilities.

5

In addition to Sierrita’s proposed facilities, non-jurisdictional power lines would be constructed 

by Tucson Electric Power Company or Trico Electric Cooperative, Inc. to supply power to the meter 

stations, MLVs, and a contractor yard. The power supply lines do not fall under the FERC’s jurisdiction, 

but are discussed in our cumulative impacts analysis. 

PUBLIC INVOLVEMENT

On May 2, 2012, the FERC began its pre-filing review of EPNG’s planned Sasabe Lateral 

Project, a precursor to the proposed Project, and established a pre-filing docket number (PF12-11-000) to 

place information related to the Project into the public record. 

EPNG hosted two public open houses in communities in the vicinity of the Project on June 5 and 

6, 2012. These open houses were conducted to inform landowners, government officials, and the general 

public about the Project. Attendees were invited to ask questions and submit any concerns. We

participated in the open houses and provided information regarding NEPA and the FERC’s environmental 

review process. 

As part of our pre-filing review, we issued a Notice of Intent to Prepare an Environmental Impact 

Statement for the Planned Sasabe Lateral Project and Request for Comments on Environmental Issues

(NOI) on August 1, 2012. The NOI was published in the Federal Register and sent to our environmental 

mailing list that includes affected landowners; federal, state, and local government agencies; elected 

officials; environmental and public interest groups; Native American tribes; local libraries; newspapers; 

and other interested parties. We subsequently issued a Notice of Public Scoping Meetings for the Planned 

Sasabe Lateral Project on September 24, 2012, that announced public scoping meetings to be held on 

October 18 and 20, 2012. On February 7 and 8, 2013, the FERC received applications from Sierrita, an 

affiliate of EPNG, for the Project, now named the “Sierrita Pipeline Project.” The Project was assigned 

FERC Docket Nos. CP13-73-000 and CP13-74-000. On March 25, 2013, Sierrita filed a route change to 

address stakeholder concerns about routing the pipeline closer to Highway 286. We subsequently issued 

a Supplemental Notice of Intent to Prepare an Environmental Impact Statement for the Sierrita Pipeline 

Project and Request for Comments on Environmental Issues on April 12, 2013, that announced the 

opening of a supplemental scoping period to gather input from the public and interested agencies due to a 

change in the Project route; and issued a Notice of Public Meeting for the Sierrita Pipeline Project on 

May 30, 2013, that announced a meeting held on June 18, 2013, to discuss Sierrita’s plans for restoring 

the Project’s right-of-way. We also participated in various interagency meetings. 

 

3 A meter station is an aboveground facility on a pipeline that has equipment for measuring the volume of gas 

flowing in the pipeline.

4 A mainline valve is an aboveground facility on a pipeline with valves for controlling the flow of gas in the 

pipeline. The valves act as gateways that can be open and closed.

5 A pipeline “pig” is a device used to clean or inspect the pipeline. A pig launcher/receiver is an aboveground 

facility where pigs are inserted or retrieved from the pipeline.
ES-3 Executive Summary

We issued a Notice of Availability of the Draft Environmental Impact Statement for the Proposed 

Sierrita Pipeline Project on October 25, 2013. The draft EIS was sent to our environmental mailing list. 

The draft EIS was filed with the U.S. Environmental Protection Agency (EPA) and a formal notice of 

availability was issued in the Federal Register, which established a 45-day comment period on the draft

EIS that ended on December 16, 2013. We held public comment meetings for the draft EIS on December 

12 and 14, 2013. 

In response to our notices and at our agency and public meetings, we received numerous 

comments from landowners, public officials, non-governmental organizations, the public, and 

government agencies regarding the Project. These comments expressed concerns with the purpose and 

need of the Project, FERC’s approach to NEPA, alternatives to the Project (including alternative routes 

and border tie-in locations), the proposed location of the pipeline, and the effects of the Project on 

resources, including waterbodies, wildlife, vegetation, threatened and endangered species, and 

unauthorized right-of-way uses. Although the comment period formally ended on December 16, 2013, all 

timely environmental comments on the draft EIS are addressed in this final EIS. 

PROJECT IMPACTS AND MITIGATION

Construction and operation of the Project could result in numerous impacts on the environment. 

We evaluated the impacts of the Project, taking into consideration Sierrita’s proposed mitigation, on

geology, soils, groundwater, surface water, wetlands, vegetation, wildlife, fisheries, special status species, 

land use, visual resources, unauthorized right-of-way uses, socioeconomics, cultural resources, air quality, 

noise, and safety. Where necessary, we are recommending additional mitigation to appropriately 

minimize or avoid these impacts. Cumulative impacts of this Project with other past, present, and 

reasonably foreseeable actions in the Project area were also assessed. In section 3 of this EIS, we also 

evaluated various alternatives to the Project, such as the No Action Alternative, system alternatives, and 

route alternatives and variations.

Based on scoping comments, agency consultations, and our independent evaluation of resource 

impacts, the major issues identified in our analysis are in regard to: waterbodies, vegetation, wildlife 

habitat, federally listed species, and illegal immigration and unauthorized right-of-way uses. Our analysis 

of these issues is summarized below and is discussed in detail in the appropriate resource sections in 

section 4. Sections 5.1 and 5.2 of this EIS contain our conclusions and a compilation of our 

recommended mitigation measures, respectively. 

Geology, Paleontology, and Soils

Potential geologic hazards in the Project area include seismicity, landslides, and subsidence. 

Sierrita would design its pipeline facilities for these hazards through the use of special construction 

materials within seismically active areas. Pipeline installation techniques effectively insulate the pipeline 

from minor earth movements. Further, pipeline and aboveground facilities associated with the Project

must be designed, constructed, operated, and maintained in accordance with U.S. Department of 

Transportation (DOT) Minimum Federal Safety Standards in 49 CFR 192. These regulations are intended 

to ensure adequate protection for the public and to prevent natural gas facility accidents and failures.

The Project would not affect known fossil locations and, based on the types of deposits

underlying the Project area, the likelihood of encountering and disturbing paleontological resources 

during Project construction is considered to be low. 

To appropriately minimize general construction-related effects on soils, Sierrita would implement 

the measures described in its Upland Erosion Control, Revegetation, and Maintenance Plan (Plan); 
Executive Summary ES-4

Wetland and Waterbody Construction and Mitigation Procedures (Procedures); Reclamation Plan; PostConstruction Vegetation Monitoring Document; Spill Prevention, Control, and Countermeasure Plan;

and Noxious Weed Control Plan. These measures would reasonably minimize erosion and increase the 

potential success of revegetation efforts. We reviewed Sierrita’s Plan and Procedures and find them 

acceptable (see appendices E and F, respectively). In response to our recommendation in the draft EIS, 

Sierrita also provided clarification as to how it would protect topsoil during construction in order to 

adequately minimize impacts related to erosion during heavy rains or flash flooding, and from wind.

Waterbody Crossings, Water Use, and Wetlands

The pipeline would cross one perennial and 206 ephemeral waterbodies. The perennial 

waterbody, the Central Arizona Project (CAP) Canal, would be crossed using the horizontal directional 

drill (HDD) method. In response to our recommendation in the draft EIS, Sierrita provided the results of 

its geotechnical investigation at the CAP Canal crossing, which documents that conditions appear 

favorable for an HDD crossing of the canal. 

Project-related impacts associated with ephemeral wash crossings are of particular concern to 

local agencies and stakeholders. Because the HDD method can avoid disturbing the bed and banks of a

wash, including riparian vegetation adjacent to the wash, we recommended in the draft EIS that Sierrita 

evaluate the use of the HDD method at certain locations along the route. Based on Sierrita’s evaluation, 

use of the HDD method would not be feasible (other than at the CAP Canal) based on one or more 

engineering and constructability factors. We reviewed Sierrita’s evaluation and agree with the findings. 

Ephemeral washes are anticipated to be dry at the time of crossing and would be crossed using 

standard upland crossing methods in accordance with all federal and state regulations and permit 

requirements, and using the measures included in Sierrita’s Plan and Procedures. Sierrita consulted with 

the Pima County Regional Flood Control District to identify the erosion hazard setback and depth of 

cover at each waterbody crossing. Certain ephemeral washes are connected to and upstream of a 

livestock tank that could support the federally threatened Chiricahua leopard frog and proposed northern 

Mexican gartersnake during monsoon season rainfalls. In response to our recommendation in the draft 

EIS, Sierrita identified ephemeral washes crossed by the Project that are also connected to and upstream 

of a livestock tank. Sierrita would adopt the construction measures (e.g., erosion control) listed in its Plan 

and Procedures at these features, which would avoid or reduce impacts on ephemeral washes. The Project 

would not affect wetlands.

Sierrita proposes to withdraw approximately 17 million gallons of water from the CAP Canal for 

hydrostatic testing, dust suppression, fire suppression, and equipment cleaning associated with noxious 

weed management. Sierrita would not use chemicals for any water withdrawals, and discharges would be 

in accordance with applicable Arizona Department of Environmental Quality Arizona Pollutant Discharge 

Elimination System permit requirements.

Vegetation, Wildlife, Fisheries, and Federally Listed and State-Sensitive Species

In response to comments on the draft EIS, we updated the Project’s vegetation impacts based on 

Natural Resources Conservation Service Ecological Site Descriptor data. The Project would affect about 

475.7 acres of Sonoran Desertscrub and 473.1 acres of Scrub-Grassland vegetation communities during 

construction, and Sierrita would maintain a permanent right-of-way and aboveground facilities, affecting 

about 200.8 acres of Sonoran Desertscrub and 178.2 acres of Scrub-Grassland. Project impacts on 

vegetation would range from short to long term to permanent due to the varied amount of time required to 

reestablish certain community types (an average of 2 to 13 years for Scrub-Grassland communities, and 

an average of 76 years for Sonoran Desertscrub communities). The Project would also affect vegetation 
ES-5 Executive Summary

communities of special concern, including monitoring tracts, the BANWR (access roads), designated 

jaguar critical habitat, and proposed northern Mexican gartersnake critical habitat. Over 34,000 protected 

plants and other Arizona native plants, including the endangered Pima pineapple cactus, were identified 

during Sierrita’s native plant surveys. In addition, 11 non-native species, including 5 species identified 

by the Arizona Department of Agriculture as prohibited, regulated, and/or restricted noxious weeds, were 

identified during Sierrita’s noxious weed surveys. Sierrita would update the number of all Arizona native 

plants prior to construction. We are recommending that Sierrita file the results of pre-construction 

surveys for Arizona native plants within the construction and permanent right-of-way.

Sierrita would construct, restore, revegetate, and monitor the right-of-way in accordance with its 

Plan, Procedures, Reclamation Plan, and Post-Construction Vegetation Monitoring Document to 

reasonably minimize impacts on vegetation. In response to our recommendations and stakeholder 

comments, Sierrita filed its revised Reclamation Plan and Post-Construction Vegetation Monitoring 

Document to include and/or clarify information regarding seeding, vegetation monitoring, and 

survivability of saguaro cactus and Palmer’s agave. Sierrita also agreed to adopt several additional 

measures in response to comments on the draft EIS regarding its Reclamation Plan and Post-Construction 

Vegetation Monitoring Plan. We agree with these modifications and are recommending that Sierrita file 

final revised versions of these plans prior to construction.

Sierrita would reasonably reduce impacts on riparian vegetation at Brown Wash, which is 

included within the area that has been designated as jaguar critical habitat, by crossing the area using a 

specialized method to reduce the construction right-of-way width to 75 feet. As a result of Sierrita’s 

Scour and Lateral Bank Migration Analysis, Sierrita also clarified its proposed right-of-way widths and 

additional temporary workspace needs based on the pipeline depth of cover required by the Pima County 

Regional Flood Control District. 

Sierrita does not intend to construct or maintain permanent access roads for use during operation 

of the pipeline, has no plans to conduct routine vegetation mowing or clearing of the right-of-way during 

pipeline operation, and stated that it would not access the right-of-way with vehicles to complete normal 

operations. Since issuance of the draft EIS, Sierrita clarified that it would use existing roads to access the 

right-of-way and would conduct noxious weed control, vegetation monitoring, and general maintenance

activities by pedestrian means. The potential spread of weeds would be controlled by implementation of 

Sierrita’s Noxious Weed Control Plan. 

The Project would affect wildlife and wildlife habitats; these impacts would be temporary, short

term, long term, or permanent, depending on the habitat type impacted. Implementation of Sierrita’s 

revised Plan, Procedures, and Reclamation Plan would reasonably minimize the effects of the Project on 

wildlife in general. Sierrita would supplement its wildlife baseline data with information obtained during 

its pre-construction surveys. We are recommending that prior to construction Sierrita file a copy of its 

surveys for wildlife species and nest sites surveys within the construction and permanent right-of-way. 

The Project would not affect any perennial or intermittent waterbodies or wetlands that support fisheries 

resources.

Construction could cause direct and indirect impacts on raptors and other migratory birds. 

Sierrita would conduct pre-construction surveys to document local occurrences of nesting birds, including 

raptors, unless construction would occur outside of the nesting periods. During construction, Sierrita 

would implement species-specific buffers around identified active raptor nests, limit construction vehicle 

traffic around active raptor nests, and consult with the FWS on further mitigation measures if an active 

raptor nest is near a blasting location. 
Executive Summary ES-6

Based on Sierrita’s consultations with the FWS and our review of existing records, five federally 

listed threatened or endangered species; one designated critical habitat; three proposed, candidate, or

special interest species; and one species with proposed critical habitat are reported to potentially occur in 

the vicinity of the Project. We requested that the FWS consider the draft EIS as the Biological 

Assessment for the Project. We determined that construction and operation of the Project may affect, but 

is not likely to adversely affect the federally listed jaguar, lesser long-nosed bat, Chiricahua leopard frog, 

and masked bobwhite quail, and designated jaguar critical habitat. We determined that construction and 

operation of the Project is likely to adversely affect the federally listed Pima pineapple cactus. Thus, we 

entered formal consultation with the FWS for Pima pineapple cactus and requested that the FWS prepare 

a Biological Opinion as to whether or not the Project would likely jeopardize the continued existence of 

this species. The FERC’s consultations with the FWS would also assist the BAWNR and U.S. Army 

Corps of Engineers in fulfilling their Endangered Species Act obligations, as necessary. 

For the Pima pineapple cactus, Sierrita revised its Reclamation Plan and Post-Construction 

Vegetation Monitoring Document after the draft EIS to detail the methods it would implement to 

transplant and monitor Pima pineapple cacti that would be directly impacted by construction. 

The remaining species (northern Mexican gartersnake, Sonoran Desert tortoise, cactus 

ferruginous pygmy-owl) are proposed, candidate, or species of special concern; and critical habitat for the 

northern Mexican gartersnake is proposed in the Project area. With Sierrita’s proposed mitigation 

measures, we determined that construction and operation of the Project is not likely to jeopardize the

northern Mexican gartersnake. However, we are conferencing with the FWS on this species in the event 

that the gartersnake becomes listed prior to initiation or completion of the Project, and are making a 

conditional determination that the Project may affect, but is not likely to adversely affect this species.

The Project may impact individual Sonoran Desert tortoise and cactus ferruginous pygmy-owl, 

but population level effects are unlikely and/or would not contribute to a trend towards federal listing. 

We determined that the Project is not likely to destroy or adversely modify proposed critical 

habitat for the northern Mexican gartersnake. However, we are conferencing with the FWS in the event 

that the proposed critical habitat becomes designated prior to initiation or completion of the Project, and 

are making a conditional determination that the Project may affect, but is not likely to adversely affect

proposed northern Mexican gartersnake critical habitat. 

In addition to the federally listed, proposed, candidate, and special interest species, Arizona 

Wildlife of Special Concern, Tier 1A and Tier 1B Species of Greatest Conservation Need, and plants 

protected by the Arizona Native Plant Law occur in Project area. We determined that, given the nature of 

the species occurrence and the measures that would be implemented as part of the Project, impacts on

state-sensitive species would be avoided or adequately minimized.

Land Use and Visual Resources

Construction and operation of the Project would result in impacts on about 995.1 and 380.2 acres, 

respectively, consisting of primarily open and developed land. About 20.9 miles of the pipeline route (35

percent) would be generally parallel to and within 250 feet of existing road or utility rights-of-way. 

Following construction, all affected areas outside the aboveground facility sites would be restored and 

allowed to revert to pre-construction conditions and uses. Sierrita would retain a 50-foot-wide permanent 

easement along the 60.9 miles of the Project route. 

The majority of land crossed by the Project (52.1 miles or about 86 percent of the Project total) is 

Arizona state trust land. Twelve roads proposed for use are located wholly or partially on the BANWR. 
ES-7 Executive Summary

Sierrita would be required to obtain an Appropriateness Determination and subsequently a Compatibility 

Determination from the FWS prior to receiving a special use permit for use of the roads, which is pending 

as of the issuance of this EIS. 

Visual resources along the pipeline route would be affected by the alteration of existing 

vegetative patterns associated with clearing of the construction and permanent pipeline rights-of-way. 

Sierrita conducted two visual assessments for areas determined to be most visible to passersby and users 

of the area. In order to effectively minimize visual impacts, Sierrita proposes to reseed disturbed areas in 

accordance with its Reclamation Plan to return the impacted vegetation to pre-existing conditions. 

Sierrita would also monitor affected areas in accordance with its Post-Construction Vegetation 

Monitoring Document for 5 years following construction. Based on the visual simulations from road 

viewpoints presented in a visual impact assessment, areas disturbed by pipeline construction would begin 

to resemble the surrounding area in about 20 years; however, some vegetation types would take as long as 

76 to 215 years to become fully re-established.

Illegal Immigration and Unauthorized Right-of-Way Use

Stakeholders have expressed their concern that the Project is a threat to security along the U.S.-

Mexico border and that the Project might exacerbate illegal activity already occurring within the Altar 

Valley. The amount of illegal activity at and near border crossings is dependent on many variables that 

are not directly measurable. We do not have any objective criteria to determine the level of significance 

of a project’s effect on or contributing to illegal activities. We acknowledge that the Project could 

provide a new pathway for existing illegal activity within the Altar Valley. 

To reduce the potential use of the right-of-way by unauthorized users, Sierrita would implement 

several construction and restoration measures and continue to work closely with land management 

agencies, private landowners, grazing lessees, and U.S. Border Patrol personnel to deter unauthorized 

access to and use of the right-of-way. In response to our recommendation in the draft EIS, Sierrita 

provided clarification describing the criteria for and sequential timing of each type of restoration measure 

to be installed following construction. We are also recommending that prior to construction Sierrita

provide a statement documenting its consultations with CBP and other applicable law enforcement 

agencies regarding its Right-of-Way, Security, and Access Control Plan6.

The U.S. Border Patrol is responsible for responding to any possible increase in human 

trafficking, narcotic trafficking, and cross border-related illegal activity resulting from the Project and, as 

a cooperating agency in the preparation of this EIS, has indicated that it has sufficient resources to 

respond to any additional illegal activity potentially induced by the Project.

Socioeconomics

Due to the large number of hotels/motels and vacant rental units available in Tucson, which is 

about 10 miles from the start of the Project, we anticipate that the majority of the 300 non-local workers

needed during Project construction would temporarily relocate to Tucson to avoid long commutes from 

other areas. During construction, the Project would benefit the state and local economies by creating a 

short-term stimulus to the affected areas through payroll expenditures, local purchases of consumables 

and Project-specific materials, and sales tax. Operational impacts of these benefits would be less. In its 

 

6 The Right-of-Way, Security, and Access Control Plan and other measures developed with law enforcement 

agencies contain sensitive security information that is intended to deter illegal activities. Therefore, this 

information would be made available to Project security personnel and law enforcement agencies only. 
Executive Summary ES-8

comments on the draft EIS, Pima County provided substantial information regarding the Project’s 

anticipated cost to the county’s public services, including but not limited to the Pima County Sheriff’s 

Department and Pima County medical examiner and public fiduciary. It cannot be determined whether 

the Project itself would cause an increase of or shift in illegal activities, deaths, etc. from what is already 

experienced throughout the Altar Valley as a result of undocumented immigrants or other unauthorized 

users. Therefore, these cost estimates are speculative. 

Cultural Resources

Cultural resource surveys are complete along the proposed pipeline route, at the aboveground 

facility sites, contractor yard locations, and along Project access roads. Cultural resource surveys 

identified 46 archaeological sites, including prehistoric and historic sites, and 180 isolated finds. Twelve 

of the sites and all of the isolated finds are recommended not eligible for listing in the National Register 

of Historic Places (NRHP) and no further work is recommended. Two sites (in-use natural gas pipelines 

on EPNG’s existing system) were determined to be exempt from section 106 of the National Historic 

Preservation Act (NHPA) review and no further work is recommended. Six NRHP eligible sites would 

be outside of the area of potential effect and, therefore, not affected by the Project. The remaining 26

sites are recommended eligible for listing in the NRHP. Impacts on 22 of the NRHP-eligible sites would 

be avoided during construction activities. Data recovery investigations would be completed at the 

remaining four NRHP-eligible sites. 

We and Sierrita contacted nine federally recognized Native American tribes. We participated in 

meetings with Native American tribes and are continuing consultations with Native American tribes. 

The review process under section 106 of the NHPA is not yet complete. To ensure that the 

FERC’s responsibilities under the NHPA are met, we are recommending that no construction activities 

begin until all required reports and any necessary treatment plans are reviewed, and the appropriate 

consultations are completed.

Air Quality and Noise

Construction of the Project would result in temporary impacts on air quality during construction. 

Because pipeline construction moves through an area quickly, air emissions caused by construction are 

typically intermittent and short term. Emissions from fugitive dust and construction activities would be 

controlled to the extent required by state and local agencies. Emissions from construction-related 

activities would not significantly affect local or regional air quality and would not cause nor contribute to 

an exceedance of the ambient air quality standards. Operation of the Project would not result in long-term 

impacts on air quality. 

Construction activity and its associated noise levels would vary depending on the phase of 

construction in progress at any one time. We conclude that there would be no significant noise impacts 

associated with construction of the Project. Based on noise attenuation calculations, the noise level 

increase attributable to HDD activities at the nearest noise-sensitive area to the CAP Canal would be 

perceivable. We are recommending that Sierrita file a noise survey after the initiation of HDD activities 

at the CAP Canal to ensure noise levels on the noise-sensitive area are mitigated. No new noisegenerating aboveground facilities are proposed for the Project. 

ALTERNATIVES CONSIDERED

The No Action Alternative was considered for the Project. While the No Action Alternative 

would eliminate the environmental impacts identified in this final EIS, international markets would be 
ES-9 Executive Summary

denied the Project objective of delivering 200,846 Dth/d of natural gas from EPNG’s existing pipeline 

system to Mexico. This denial might result in greater reliance on alternative fossil fuels, such as coal or 

fuel oil, or both. Other fossil fuels are not as clean as natural gas; however, renewable sources such as 

solar and wind are not always reliable or available in sufficient quantities to support most market 

requirements, including baseload electric generating facilities, as is the case here.

A system alternative for the Project would need to be able to transport similar volumes of natural 

gas to Sasabe, Arizona. We did not identify any existing pipeline systems that could meet the purpose 

and need of the Project without expansion. Based on our knowledge of other systems, construction and 

operational impacts associated with system alternatives would be greater than those of the Project due to 

the amount of looping and new construction required to connect the systems to the Project terminus. 

Consequently, no system alternatives were identified that are environmentally preferable to the Project.

We evaluated eight major route alternatives to the Project route. Seven of these would not offer a 

significant environmental advantage over the Project route and, therefore, we eliminated them from 

further consideration. One of these route alternatives would meet the Project objectives, would be 

technically and economically feasible, and would offer an environmental advantage over the proposed 

route. However, this route alternative would be within the BANWR, which is managed by the FWS and

thus would be subject to FWS approval. The FWS has determined that this route alternative would not 

promote achievement of the mission of the National Wildlife Refuge System or the purposes for which 

the BAWNR was established. As a result, the FWS has indicated it cannot permit this alternative. 

Therefore, based on this land use conflict, we are not recommending this alternative. 

In response to comments on the draft EIS, we also discussed alternative delivery locations at the 

U.S.-Mexico border. We determined that alternative delivery points would not meet the Project 

objectives.

Since issuance of the draft EIS, Sierrita adopted a route variation to address a landowner request 

to move the pipeline to a more favorable location on his property and to avoid a water well. We agree. 

As such, Sierrita’s variation was analyzed as part of the proposed Project in section 4.0 of this EIS. 

We also analyzed two route variations based on landowner requests. We are not recommending 

either variation because they would result in more environmental impacts and would not offer any 

significant environmental advantages over the proposed route. 

MAJOR CONCLUSIONS

We determined that construction and operation of the Project would result in limited adverse 

environmental impacts. This determination is based on a review of the information provided by Sierrita 

and further developed from data requests; field investigations; scoping; literature research; alternatives 

analyses; and contacts with federal, state, and local agencies, Native American tribes, and other 

stakeholders. We conclude that the approval of the Project would have some adverse environmental 

impacts, but, with the exception of the Pima pineapple cactus, these impacts would be reduced to lessthan-significant levels. Although many factors were considered in this determination, the principal 

reasons are:

 Sierrita would adequately minimize impacts on natural and cultural resources during 

construction and operation of the Project by implementing its Plan and Procedures;

Reclamation Plan; Post-Construction Vegetation Monitoring Document; Noxious Weed 

Control Plan; Fugitive Dust Control Plan; Blast Plan; Site-Specific Horizontal 

Directional Drill Crossing Plan for the CAP Canal; HDD Contingency Plan and 
Executive Summary ES-10

Feasibility Assessment; Hydrostatic Testing Best Management Practices Plan; Spill 

Prevention, Control, and Countermeasures Plan; Fire Protection Plan; and 

Unanticipated Discovery Plan;

 the FERC staff would complete Endangered Species Act consultations with the FWS 

prior to allowing construction to begin;

 the FERC staff would complete the process of complying with section 106 of the NHPA 

and implementing the regulations at 36 CFR 800 prior to allowing construction to begin; 

and

 an environmental inspection and mitigation monitoring program would ensure 

compliance with all mitigation measures that become conditions of the FERC 

authorizations and other approvals.

In addition, we developed site-specific mitigation measures that Sierrita should implement to 

further reduce the environmental impacts that would otherwise result from construction of the Project.

We are recommending that these mitigation measures be attached as conditions to any authorization 

issued by the Commission. These recommended mitigation measures are presented in section 5.2 of the 

EIS.