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Interstate 11 Corridor Tier 1 Environmental Impact Statement, Nogales to Wickenburg
Interstate 11 Corridor Tier 1 Environmental Impact Statement, Nogales to Wickenburg

Environmental Process

The Tier 1 Environmental Impact Statement (EIS) Process

The Tier 1 EIS is following a process outlined by NEPA. It is designed to ensure that reasonable transportation alternatives are considered, that community input plays a key role, and that the environmental and community effects are fully disclosed.

The process includes:

A Notice of Intent (NOI) to prepare a Tier 1 EIS was published in the Federal Register on May 20, 2016. A copy of the NOI is available on the Documents page. General information regarding the proposed action was shared, along with notification of the scoping process and related meetings and input opportunities. As part of the NOI, FHWA and ADOT invited all interested individuals, organizations, public agencies, and Native American Tribes to comment on the scope of the Tier 1 EIS, including the purpose and need, alternatives to be studied, impacts to be valuated, and evaluation methods to be used. The formal scoping period spanned 45 days from publication of the NOI through July 8, 2016.

Potential issues, opportunities, and concerns were solicited from various agencies, the community, and others to understand the scope of topics to address during the study. Scoping activities included a total of nine agency and public meetings across the I-11 Corridor study area, combined with an online survey and solicitation of comments via mail, email, and telephone for those unable to attend the meetings in person. The online survey requested the same information as the comment form distributed at the meetings. Comments were welcomed at any point in the process, but only those submitted through the end of the scoping period (July 8, 2016) were integrated into the Scoping Summary Report as formal documentation of community issues, opportunities, and concerns. A copy of the Scoping Summary Report is included on the Documents page.

Following scoping, a wide range of corridor alternatives were developed. For the purposes of the alternatives development and screening, the I-11 Corridor study area is divided into three sections – South, Central and North, with the ultimate goal to piece together a set of corridor-wide alternatives. The alternative corridor options were screened based on a series of criteria, including consistency with the Purpose and Need. The screening has enabled FHWA and ADOT to refine and further consider corridor alternatives that best meet the overall Purpose and Need of the I-11 Corridor, as well eliminate corridor options that do not adequately meet the Purpose and Need. Ultimately, the screening process will yield a reasonable range of corridor alternatives, along with a No Build alternative – or “do nothing” scenario – that will advance into the Tier 1 EIS document for more detailed study.

The evaluation process is outlined below.

The 2,000-foot study corridor is not meant to represent the full footprint of the I-11 Corridor, meaning the proposed transportation facility is not intended to be 2,000 feet wide. Depending on the number of lanes required, a highway facility is likely to use less than a quarter of this width for the right-of-way, which includes travel lanes, shoulders, median, and other possible improvements like frontage roads. Additional area within this 2,000 feet could be used for other transportation facilities in the future, like rail or utilities, as demand warrants.

Identifying a preferred 2,000-foot corridor as the main outcome of Tier 1 EIS advances the study process of better identifying the location for an I-11 Corridor. In the Tier 2 environmental reviews, instead of reviewing a study area that ranges five to 25 miles in width, multiple alternatives can be evaluated within the 2,000-foot area.

A. Initial Range of Corridor Options

An initial range of corridor options for each of the three study area sections is developed based on four primary sources:

  • Prior I-11 Study: The 2014 IWCS performed an alternatives analysis and consensus-building exercise to recommend I-11 corridor alternatives for further analysis in this environmental review process.
  • Agency Scoping Input: During scoping, agencies and tribal communities provided feedback on potential corridor alternative preferences, considerations, and/or constraint areas, including potential locations for a transportation facility or areas to avoid.
  • Public Scoping Input: During scoping, the general public also provided feedback on potential corridor alternative preferences, considerations, and/or constraint areas, including potential locations for a transportation facility or areas to avoid.
  • Technical Analysis: A software tool will be used that simultaneously considers engineering factors and avoids sensitive resources to both identify and screen out corridor alternatives that potentially have substantial impacts and other issues.

To promote comprehensive coverage of the I-11 Corridor Study Area, the information and suggestions from these four sources will be used to identify reasonable potential corridor alternatives to be screened during the preparation of the ASR.

B. Comparative Evaluation

Alternative corridor options will be screened based on a series of criteria and specific measures to ensure they meet and achieve the underlying purpose of the I-11 Corridor and supporting needs. A qualitative (high/medium/low) approach is used to decide which corridor options are more effective at meeting the Corridor’s Purpose and Need. The alternatives will be compared against how well each option:

  • Addresses population and employment growth
  • Mitigates congestion and improves travel times
  • Improves system linkages and interstate mobility
  • Improves access to economic activity centers
  • Minimizes direct impacts on sensitive environmental resources

The best-performing options within each section (North, Central, and South) will be advanced into the Tier 1 EIS, where they will be subject to more detailed analysis. At this point, the corridor options will be pieced together to create a series of end-to-end alternatives that stretch from Nogales to Wickenburg. These alternatives are intended to represent the full series of ideas obtained during scoping. Public informational meetings are scheduled to review and comment on the alternatives evaluation process.

C. Detailed Definition of Alternatives

The final step in the alternatives analysis process will be to provide more detailed definition of the Corridor Build Alternatives and the No Build Alternative recommended for further analysis in the Tier 1 EIS phase. They will be described in sufficient detail to identify limits of the 2,000-foot corridor alternatives, as well as the potential right-of-way requirements to accommodate the typical cross section of a high capacity transportation facility from Nogales to Wickenburg. This information will be the basis for determining potential impacts on the human and natural environments during the Tier 1 EIS.

The Draft Tier 1 EIS is an official document issued during the NEPA process that documents the detailed analysis of the alternatives. The results of this analysis will identify a Recommended Corridor Alternative (expected to be 2,000’ wide), including a phased implementation plan, which thoughtfully divides the 280-mile corridor into smaller segments that may advance as separate, independent projects following completion of the Tier 1 EIS process.

In the Draft Tier 1 EIS, alternatives identified through the Alternatives Evaluation process, known as the Build Corridor Alternatives, will be compared against a No Build Alternative (i.e., do-nothing option). The Draft Tier 1 EIS will consider possible effects that alternatives might have on a variety of social, environmental, and economic resources, as well as understanding their direct, indirect, and cumulative effects on the surrounding environment. These resources may include:

  • Land use
  • Socioeconomic and Environmental Justice
  • Economic Impacts
  • Historical, Archaeological, Architectural, or Cultural Resources
  • Section 4(f) Evaluation
  • Noise and Vibration
  • Visual and Aesthetics
  • Air Quality
  • Hazardous Materials
  • Geology, Soils, and Farmlands
  • Waters Resources
    • Water Quality
    • Flood Hazards, Floodplains and Wetlands
  • Biological Resources
    • Vegetation and Wildlife Habitat
    • Threatened and Endangered Species

The Draft Tier 1 EIS document will be circulated for public and agency comment over a 45-day review period, where the public and agencies will have an opportunity to review and comment. Public hearings will be held to present the information and encourage formal comments. Locations for viewing the document as well as public meeting dates will be announced and included under the Community Outreach and Public Meetings page. When the Draft Tier 1 EIS document is completed, it will be available on the Documents page.

Upon completion of the public hearing process, the project team will respond to comments received on the Draft Tier 1 EIS, conduct additional analysis, and coordinate with stakeholders, as needed, in preparation of finalizing the Tier 1 EIS.

FHWA and ADOT will complete the environmental review process with the preparation of a Final Tier 1 EIS. The Final Tier 1 EIS will respond to comments received on the Draft Tier 1 EIS and identify the Preferred Corridor Alternative for the I-11 Corridor between Nogales and Wickenburg. The Final Tier 1 EIS will be made available online on the Documents page.

The Final Tier 1 EIS will be made available for a designated public review period. The Final Tier 1 EIS will be made available online on the Documents page.

ADOT and FHWA will complete the environmental review process with preparation of a Record of Decision (ROD). The ROD will confirm the Selected Corridor Alternative (Build or No Build); present the basis for the decision; describe the alternatives considered; and provide strategies to avoid, minimize, and compensate for environmental impacts. FHWA would ultimately approve the ROD as the Federal Lead Agency under NEPA. The ROD will be made available online on the Documents page.

Community Outreach

A continuous community outreach process has been integrated into every step of the project to provide residents, businesses, the traveling public and other interested parties with multiple opportunities for meaningful participation in the process. Public meeting information is identified on the Community Outreach and Public Meetings page.