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Guidance for Determining De Minimis Impacts to Section 4(f) Resources

This guidance was superseded in July 2012. Current guidance is available at

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U.S. Department of Transportation
Federal Highway Administration
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Subject: ACTION: Guidance for Determining De Minimis Impacts to Section 4(f) Resources
December 13, 2005
From: Original Signed by:
Cynthia J. Burbank
Associate Administrator, Planning, Environment and Realty, FHWA
Brigid Hynes-Cherin, Associate Administrator
for Planning and Environment, FTA
Reply to Attn of:
To: FHWA Division Administrators
FTA Regional Administrators

Section 6009(a) of the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU), Pub. L. 109-59, amended existing Section 4(f) legislation at Section 138 of Title 23 and Section 303 of Title 49, United States Code, to simplify the processing and approval of projects that have only de minimis impacts on lands protected by Section 4(f). This is the first substantive revision of Section 4(f) legislation since passage of the U.S. Department of Transportation Act of 1966. This revision provides that once the U.S. Department of Transportation (DOT) determines that a transportation use of Section 4(f) property, after consideration of any impact avoidance, minimization, and mitigation or enhancement measures, results in a de minimis impact on that property, an analysis of avoidance alternatives is not required and the Section 4(f) evaluation process is complete.

Section 6009(c) of SAFETEA-LU requires the U.S. DOT to conduct a study and issue a report on the implementation of the new Section 4(f) provisions. The study will include evaluation of: 1) the implementation processes developed and the resulting efficiencies; 2) the post-construction effectiveness of any impact mitigation and avoidance commitments adopted as part of the projects; and 3) the number of projects determined to have de minimis impacts, including information on the location, size, and cost of the projects. The initial study and report will address the first three years of implementation. The Federal Highway Administration (FHWA) Division and Federal Transit Administration (FTA) Regional Offices should maintain a record of the projects for which de minimis findings were made and track the progress of those projects in order to facilitate the future evaluation of the post construction effectiveness of any commitments of mitigation made as part of the de minimis finding. Additional guidance and information regarding the study and report will be provided in the future.

For basic information regarding Section 4(f) applicability and compliance, please consult the March 1, 2005, FHWA Section 4(f) Policy Paper. This guidance will be incorporated in a future revision of the Section 4(f) Policy Paper. Although the Section 4(f) Policy Paper was developed by FHWA, FTA and other modal administrations generally follow the guidance, where appropriate and applicable to transit projects and other proposals. For additional information or assistance please contact Lamar Smith, FHWA at or 202-366-8994; or Joseph Ossi, FTA at or 202-366-1613.

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Updated: 1/17/2013
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