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SCEA Training
Training Modules / Interactive Presentation

Introduction :: Presentation Format & SCEA Overview
Module 1 :: How to Determine Which Resources Should be Considered in a SCEA
Module 2 :: How to Establish the SCEA Geographical Boundary
Module 3 :: How to Determine SCEA Time Frames
Module 4 :: How to Develop SCEA Land Use Information
Module 5 :: How to Prepare the Analysis & Reach SCEA Conclusions
Module 6 :: Presentation of SCEA in the Environmental Documentation


Slide 1 SCEA Introduction

Maryland State Highway Administrations Secondary and Cumulative Effects Analysis Guidelines

For Environmental Impact Statements and Environmental Assessments

Rev. 07/21/99

Slide 2 Module Overview

(Module 1) How to determine which resources should be considered in a SCEA .
(Module 2) How to establish the SCEA Geographical Boundary.
(Module 3) How to determine SCEA time frames.
(Module 4) How to develop SCEA land use information.
(Module 5) How to prepare the analysis & Reach SCEA Conclusions.
(Module 6) Presentation of SCEA in the Environmental Documentation

Slide 3 Training Goals

Provide SHA employees, federal and state resource agencies, local governments and consultants:

  • Consistent procedures in conducting a secondary and cumulative effects analysis.
  • A clear definition of direct impacts, secondary impacts and cumulative effects.
  • A clear understanding of how SCEA applies to project development.
  • Knowledge to facilitate the review of SCEA documentation.

Slide 4 SHA Case Studies (Project Locations)

map D-link

Slide 5 SCEA Background

  • NEPA and CEQ regulations
  • Secondary versus cumulative effects
  • SHAs SCEA Guidelines
  • SCEA and the SHA Project Planning Process
  • Levels of Environmental Documentation

Slide 6 NEPA & CEQ Regulations

Compliance with the National Environmental Policy Act (NEPA) and Council on Environmental Quality (CEQ) regulations require that the secondary and cumulative effects of a project be examined along with direct impacts (40 CFR 1508.25 (c)).

Slide 7 Secondary versus Cumulative Effects

Secondary Effects Effects which are caused by the action and are later in time or farther removed in distance, but are still reasonably foreseeable. Secondary effects may include growth inducing effects and other effects related to induced changes in the patterns of land use, population density or growth rate, and related effects on air and water and other natural systems, including ecosystems (40 CFR 1508.8(b)).
Secondary effects are a subset of cumulative effects. An example of secondary effects is:

  • Commercial and residential development following construction of a highway or the addition of new access points to a highway.

Slide 8 Secondary versus Cumulative Effects (continued)

Per SHA's SCEA Guidelines, secondary effects may occur:

  • When local governments or developers identify planned development that will not proceed without a specific project or transportation alternative.
  • Zoning or land use changes that may occur (based upon professional judgement) as a result of each project alternative retained for detailed study.

Slide 9 Secondary versus Cumulative Effects (continued)

Cumulative Effects The impact on the environment which results from the action when added to other past, present and reasonably foreseeable future actions regardless of what agency (federal,or nonfederal) or person undertakes such actions (40 CFR 1508.7, 1997). Some examples of cumulative effects include:

  • Incremental loss of wetlands under the Nationwide permit program.
  • Forest fragmentation related to roadway rightofway construction and other development over time.
  • Population declines in nesting birds from multiple tree harvests over time.
  • Increase in stormwater peak flows and pollutant loadings from commercial and residential development.
  • Decrease in active farmlands due to development pressures.

Slide 10 NEPA & CEQ Regulations (continued)

Federal agencies have routinely addressed direct, and, to a lesser extent, secondary effects of their proposed actions on the environment.

Analyzing cumulative effects was more challenging because of the difficulty of defining geographic and time boundaries.

As a result, very little attention has been given to cumulative effects until recently. The availability of data, particularly agency published resource reports/ inventories, coupled with the development of GIS technology, have contributed to the increase in feasibility of incorporating secondary/cumulative effects analysis in the NEPA process.

Slide 11 SHA Guidelines

Provide general purpose procedures and a consistent framework for preparing a SCEA . This includes:

  • Introduction
  • Scoping/Initial SCEA activities
  • Analysis
  • Mitigation

Slide 12 SHA Guidelines (continued)


  • Definitions Secondary and Cumulative
  • Combinations of Direct, Secondary and/or Cumulative Effects
  • Levels of Environmental Documentation

Scoping/Initial SCEA Activities

  • Resource Identification/Data Availability.
  • Setting the SCEA Geographical Boundary.
  • Setting SCEA Time Frames Past and Future.

Slide 13 SHA Guidelines (continued)


  • Refinement of Geographical Boundaries and Resources
  • Data Collection and Mapping
  • Analysis Methodologies Trends, Overlays, Matrices, Interviews


  • Preparing the Written SCEA Summary
  • Responsibilities of SHA, agencies and locals
  • Existing regulations and protective measures

Slide 14 SHA Guidelines (continued)

Do not apply a cookie cutter approach

Each SCEA is unique based upon its Project Purpose and Need and its Alternatives Retained for Detailed Study. Do not apply a cookie cutter approach!

Slide 15 SHA Guidelines (continued)

The following combinations of direct, secondary and/or cumulative impacts of an alternative on a resource may be encountered in transportation projects:

Direct, Secondary and Cumulative Impacts
Typically, larger capacityadding or economic development projects. SHA examples include MRECAS, Hickory Bypass and US Route 1.

Direct and Cumulative Impacts Only
Typically, smaller improvementtype projects, such as bridge replacements and widenings to alleviate congestion/improve safety, but can include larger projects. SHA examples include US 113 Planning Study, MD 4 and MD 5.

Secondary and Cumulative Impacts only
Probably not encountered often.

If project alternatives do not result in direct or secondary impacts upon a resource, then no further analysis of that resource is required.

Slide 16 SCEA & the SHA Project Planning Process

STAGE I Preliminary Alternatives Development through the Public Alternates Workshop.
STAGE II Detailed Environmental and Engineering Studies through circulation of the Draft Environmental Document and the conducting of the Location/Design Public Hearing.
STAGE III Identification of the selected alternative and preparation of the decision document.

Slide 17 SCEA & the SHA Project Planning Process (continued)

See SHA Project Planning Stages graphicD-link

IRM Interagency Review Meeting

Slide 18 Levels of Environmental Documentation

SHA's SCEA Guidelines apply to:

  • Environmental Impact Statements (EIS), including Supplemental Environmental Impact Statements (SEIS's)
  • Environmental Assessments (EA's)

Exercise 1 | Back to top

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