AASHTO PG12-2011 AASHTO Practitioner's Handbook - Assessing Indirect Effects and Cumulative Impacts under NEPA.pdf

1、iAssessing Indirect Effects and Cumulative Impacts under NEPAAASHTO PrAcTiTiOnerS HAndbOOkThe Center for Environmental Excellence by AASHTO produces the Practitioners Handbooks. The Handbooks provide practical advice on a range of environmental issues that arise during the planning, development, and

2、 operation of transportation projects. Each Handbook is developed by the Center in cooperation with an advisory group that includes representatives of the Federal Highway Administration (FHWA), the Federal Transit Administration (FTA), State departments of transportation (DOTs), and other agencies a

3、s appropriate.The Handbooks are primarily intended for use by project managers and others who are responsible for coordinating compliance with a wide range of regulatory requirements. With their needs in mind, each Handbook includes: A background briefing; Key issues to consider; and Practical tips

4、for achieving compliance.In addition, key regulations, guidance materials, and sample documents for each Handbook are posted on the Centers web site at http:/environment.transportation.orgASSeSSing indirecT effecTS And cumulATive imPAcTS under nePAThis Handbook is intended to assist practitioners in

5、 assessing indirect effects and cumulative impacts in the evaluation of transportation proj-ects under the National Environmental Policy Act (NEPA).Issues covered in this Handbook include: Understanding the definitions of direct effects, indirect effects, and cumulative impacts Gathering the informa

6、tion needed for the analysis Deciding the appropriate scope and level of detail Carrying out the analysis Identifying mitigation opportunities Documenting the analysis Using the transportation planning process to support NEPA-level studies of indirect effects and cumulative impactsAmerican Associati

7、on of State Highway and Transportation Officials12April 2011Center for Environmental Excellence by AASHTOii Using the Transportation Planning Process to Support the NEPA ProcessCopyright 2011, Center for Environmental Excellence by AASHTO (American Association of State Highway and Transportation Off

8、icials). All Rights Reserved. This book, or parts thereof, may not be reproduced in any form without written permission of the publisher. Printed in the United States of America.This material is based upon work supported by the Federal Highway Administration under Cooperative Agreement No. DTFH61-07

9、-H-00019. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the Author(s) and do not necessarily reflect the view of the Federal Highway Administration. 2009 by the American Association of State Highway and Transportation Officials. All rights rese

10、rved. Duplication is a violation of applicable law.1Assessing Indirect Effects and Cumulative Impacts under NEPAThe requirement to assess indirect and cumulative impacts of proposed federal actions was established in the Council on Envi-ronmental Quality (CEQ) regulations implementing the National E

11、nvironmental Policy Act (NEPA). Indirect effects are caused by the project or plan, but are separated from direct effects by time and/or distance. Indirect effects include induced growth and related environmental impacts. Cumulative impacts are the aggregate result of the incremental direct and indi

12、rect effects of a project or plan, the effects of past and present actions, and effects of reasonably foreseeable future actions by others on resources of concern.This Handbook focuses primarily on the assessment of indirect effects and cumulative impacts for individual transportation proj-ects. Thi

13、s Handbook also briefly describes a range of approaches for using the statewide or metropolitan transportation planning process to address indirect effects and cumulative impacts for a region or corridor.A consistent theme throughout this Handbook is the importance of maintaining a clear distinction

14、 between an indirect effects analysis and a cumulative impacts analysis. For that reason, those analyses are addressed separately in the Practical Tips sec-tion of the Handbook.Overview 2009 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication i

15、s a violation of applicable law.2 Assessing Indirect Effects and Cumulative Impacts under NEPAbackground briefingThis section introduces the key terms and concepts used in the assessment of indirect effects and cumulative impacts in the NEPA process. It also briefly describes key guidance documents

16、and reference materials, which are discussed in more detail in the Practical Tips section.Key Terms and ConceptsDirect Effects. The CEQ regulations state that direct effects are “caused by the action and occur at the same time and place” (40 C.F.R. 1508.8). Direct effects are typically well understo

17、od and predictable. Direct effects are action-focused effects. Ex-amples of common direct effects for transportation projects include residential and business displacements, the fill of wetlands to construct a roadway, or the removal of a historic structure. Indirect Effects. Indirect effects are th

18、ose effects that “. . . are caused by the action and are later in time and farther removed in distance, but are still reasonably foreseeable.” Indirect effects “may include growth-inducing effects and other effects related to induced changes in the pattern of land use, population density or growth r

19、ate, and related effects on air and water and other natural systems, including ecosystems.”(40 C.F.R. 1508.8). Indirect effects are action-focused effects.There are two primary types of indirect effects: induced growth (or growth-influencing) effects and encroachmentalteration effects. Induced-Growt

20、h Effects. Induced-growth effects are changes in the location, magnitude, or pace of future development that result from changes in accessibility caused by the project. An example of an induced-growth effect is commercial development occurring around a new interchange and the environmental impacts a

21、ssociated with this development. EncroachmentAlteration Effects. Encroachmentalteration type indirect effects are physical, chemical, or biological changes in the environment that occur as a result of the project but are removed in time or distance from the direct ef-fects. An example of an encroach

22、ment-alteration type indirect effect is a long term decline in the viability of a population of a particular species as a result of habitat fragmentation caused by the project. These types of effects are sometimes described as direct effects. The categorization is not important as long as the NEPA d

23、ocument demonstrates that the effects have been considered.Cumulative Impacts. A cumulative impact is “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

24、 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).Distinctions between Direct, Indirect, and Cumulative ImpactsType of effecT DirecT inDirecT cum

25、ulaTiveNature of Effect Typical/Inevitable/Predictable Reasonably Foreseeable/ProbableReasonably Foreseeable/ProbableCause of Effect Project Projects Direct and Indirect EffectsProjects Direct and Indirect Effects and Effects of Other ActivitiesTiming of EffectProject Construction and Implementation

26、At Some Future Time other than Direct EffectIn the Past, at Time of Project Construction, or in the FutureLocation of Effect At the Project LocationWithin Boundaries of Systems Affected by the ProjectWithin Boundaries of Systems Affected by the ProjectSource: NCHRP Report 403, Guidance for Estimatin

27、g the Indirect Effects of Proposed Transportation Projects (1998).“But-For” Relationship. As a general rule, a project may be considered to cause an impact if the project is necessary for the impact to occur. This relationship is sometimes described as a “but-for” relationship: that is, the developm

28、ent would not have occurred but for the transportation project. A but-for condition can exist as a matter of lawe.g., if an action cannot take place without a permit. A but-for condition can also exist as a matter of facte.g., if a developer would choose not to build a shopping mall unless a nearby

29、road is expanded. 2009 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.3Assessing Indirect Effects and Cumulative Impacts under NEPANecessary vs. Sufficient. Even when a project is a necessary condition for

30、an impact to occur, there may beand often areother conditions that also need to be present in order for the impact to occur. Thus, while the transportation project may be a necessary condition, it may not be a sufficient condition for the impact to occur. Other conditions that may be necessary for a

31、 development project typically include but are not limited to: suitable, available land for development or redevelopment. economic conditions that support development, e.g., markets, acceptable rate of return on investment in land pur-chase, design, construction, and other costs. zoning and other la

32、nd use controls and policies suitable for the type of development suggested by market conditions. other infrastructure that supports development, e.g., water and sewer service. amenities, e.g., schools, access to recreational opportunities.“Reasonably Foreseeable.” Indirect effects and cumulative im

33、pacts must be considered if they are reasonably foreseeable. Impacts that are merely possible, or that are considered “speculative,” are not reasonably foreseeable. In one of the leading court decisions on this topic, the U.S. Court of Appeals for the First Circuit explained the legal standard as fo

34、llows: Only those effects that are “likely” (or “foreseeable” or “reasonably foreseeable”) need be discussed, and, as in other legal contexts, the terms “likely” and “foreseeable,” as applied to a type of environmental impact, are properly interpreted as meaning that the impact is sufficiently likel

35、y to occur that a person of ordinary prudence would take it into account in reaching a decision.1The CEQ provides a similar interpretation, requiring agencies to consider the “uncertain, but probable” indirect effects of their actions: The EIS must identify all the indirect effects that are known, a

36、nd make a good faith effort to explain the effects that are not known but are “reasonably foreseeable.” If there is total uncertainty about the identity of future land owners or the nature of future land uses, then of course, the agency is not required to engage in speculation or contemplation about

37、 their future plans. But, in the ordinary course of business, people do make judgments based upon reasonably foreseeable occurrences. It will often be possible to consider the likely purchasers and the development trends in that area or similar areas in recent years; or the likelihood that the land

38、will be used for an energy project, shopping center, subdivision, farm or factory. The agency has the responsibility to make an informed judgment, and to estimate future impacts on that basis, especially if trends are ascertainable or potential purchasers have made themselves known. The agency canno

39、t ignore these uncertain, but probable, effects of its decisions.2Other Terminology Issues. Just as it is important to understand when similar terms have different meanings, it also is important to understand when different terms have the same meaning. There is no substantive distinction in the CEQ

40、regulations between “effect” and “impact,” nor is there a substantive distinction between “indirect” and “secondary.” To avoid confusion, it is good practice to use these terms consistently within a NEPA document. Effects vs. Impacts. The CEQ regulations use the terms “indirect effects” (40 C.F.R. 1

41、508.8) and “cumulative impacts” (1508.7). To be consistent with usage in the CEQ regulations, this Handbook also uses the terms “indirect effects” and “cumulative impacts.” This terminology is a matter of convention, and does not reflect a substantive distinction between the meaning of “effects” and

42、 “impacts,” which are described as synonymous in the CEQ regulations.3The CEQ itself has not been consistent in its use of these terms: while the regulations refer to cumulative impacts, several CEQ guid-ance documents refer to “cumulative effects,” including the CEQs handbook on this topic. In prac

43、tice, it is acceptable to refer to effects or impacts, as long as the terms are used consistently.1 Sierra Club v. Marsh, 976 F.2d 763, 767 (1st Cir. 1992).2 CEQ, Forty Most Asked Questions Concerning CEQs National Environmental Policy Act Regulations, 46 Fed. Reg. 18026 (March 16, 1981), Response t

44、o Question 18.3 40 C.F.R. 1508.8 (“Effects and impacts as used in these regulations are synonymous. Effects includes ecological (such as the effects on natural resources and on the components, structures, and functioning of affected ecosystems), aesthetic, historic, cultural, economic, social, or he

45、alth, whether direct, indirect, or cumulative. Effects may also include those resulting from actions which may have both beneficial and detrimental effects, even if on balance the agency believes that the effect will be beneficial.”). 2009 by the American Association of State Highway and Transportat

46、ion Officials. All rights reserved. Duplication is a violation of applicable law.4 Assessing Indirect Effects and Cumulative Impacts under NEPA Indirect vs. Secondary. The term “secondary effects” is sometimes used as a substitute for “indirect effects.” While use of this term does not affect the le

47、gal adequacy of the analysis, the CEQ regulations refer only to “indirect effects” and do not use the term “secondary effects.” For consistency with the CEQ regulations, this Handbook exclusively uses the term “indirect effects.”Key Reference DocumentsThere are many guidance documents and reference

48、materials that provide advice for practitioners on how to conduct indirect effects and cumulative impacts analyses. See the References section of this Handbook for additional information on these guid-ance documents. CEQ. In 1997, the CEQ issued the handbook, Considering Cumulative Effects under the

49、 National Environmental Policy Act. This handbook is non-binding and is not considered a guidance document, but has been widely followed. There is no comparable CEQ handbook or guidance document for indirect effects. In 2005, the CEQ issued a memorandum on consideration of “past actions” in cumulative impacts analyses. FHWA. In 2003, FHWA issued an interim guidance document, Questions and Answers Regarding the Consideration of Indirect and Cumulative Impacts in the NEPA Process. This interim guidance has never been finalized. It remains F