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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

Module 5

Slide 1 How to Prepare Analysis and Reach SCEA Conclusions

Slide 2 Overview


  • Levels of SCEA
  • Data Collection
  • Regulations/Laws
  • Map Environmental Resources and Land Use (Module 4)
  • Identify Methodologies/Conduct Analysis
  • How to Reach SCEA Conclusions

Slide 3 Introduction

  • The analysis phase begins following SHAs request for concurrence on Alternatives Retained for Detailed Study.
  • Varying levels of analysis (detail) may be used for different types of projects.
  • Analysis results may be quantitative and/or qualitative.
  • It is important to consider regulatory programs in the analysis.
  • The SCEA results for Alternatives Retained for Detailed Study are included in the draft and final environmental document.

Slide 4 Introduction (continued)

Do not develop predictive models to fill in data gaps. Instead, use existing readily available data.

Slide 5 Introduction (continued)

Developing SHA's SCEA Consultant Team

  • It is recommended that the consultant responsible for conducting direct impact analyses also conduct the SCEA to ensure compatibility of findings for direct, secondary and cumulative impacts.

(Particularly important for SocioEconomic Resources).

  • If different natural environmental, cultural and socioeconomic consultants are used, it is important that land use data layers be transmitted by the socioeconomic consultant to the other consultants for analysis consistency.

Slide 6 Introduction (continued)

Developing SHA's SCEA Consultant Team (continued)

  • Conduct an early team coordination meeting if multiple consultants are being used to conduct the SCEA . This will avoid duplication of the work effort and help ensure consistency.
  • In situations where there are multiple consultants, the consultant should be clear in which past, present and future land use scenarios to analyze.

Slide 7 Introduction (continued)

  • Refinement of SCEA Boundaries
    • Prior to conducting the SCEA technical analysis, it may be necessary to adjust the SCEA geographical boundary based upon agency coordination and/or new information learned collecting land use information.
    • Any adjustments to the SCEA geographic boundary should be completed prior to undertaking any of the analytical methodologies proposed to assess impacts within the SCEA boundary.

Slide 8 Levels of SCEA

The level of SCEA analysis should be tailored to the project type. The following factors are considered in determining the level of analysis:

Availability of Data

  • Limit quantitative analysis to resources having readily available quantitative data.
  • Conduct qualitative analysis for resources lacking readily available quantitative data.
  • Document the rationale for the level of analysis conducted.

Slide 9 Levels of SCEA (continued)

  • Presence of Direct or Secondary Impacts
    • If project alternatives do not result in direct or secondary impacts on a resource, no further analysis is necessary although documentation must occur.
  • Resources within the SCEA Boundary
    • If secondary or cumulative effects for a resource are not relevant to decisions about the proposed action, it is not necessary to perform SCEA for that resource (e.g. soils and geology).

Slide 10 Data Collection

  • Collect Appropriate Data

Slide 11 Regulations & Laws

  • Regulatory Programs
    • Certain regulatory programs, (i.e., wetlands and public parklands) essentially provide a degree of protection from direct impacts to applicable resources due to the fact that they have teeth and contain mitigation requirements. This is especially important when conducting trends analysis. Predicting a future condition based on a past trend should factor in how recent laws and regulations will alter the trend of impacts to a particular resource. These programs should be considered in the analysis portion of the SCEA .

Slide 12 Regulations & Laws

Regulatory Program

Agency Having Jurisdiction

Applicable Resource

County Flood Management Ordinances

County Planning Offices or Departments of Environmental Resources


1991 State Forest Conservation Act

DNR administered by local government


County Forest Conservation Act

County Planning Offices or Department of Environmental Resources


1973 Endangered Species Act (Federal)

USFWS, DNR Wildlife and Heritage Division


1973 Maryland Endangered Species Act (State)

Counties (private lands within Critical Areas)

Rare, Threatened and Endangered Species

1975 Maryland Nongame and Endangered Species Conservation Act (State)



Maryland Agricultural Land Preservation Program and Transfer of Development Rights (TDR) Program


County Planning Offices or Department of Environmental Protection

Active Farmland

County Agricultural Land Preservation Ordinances

1966 National Historic Preservation Act (Section 106)


Historic and Archaeological Sites

1966 National Historic Preservation Act(Section 110)

Maryland Historical Trust


Archeological and Historic Preservation Act

Advisory Council on Historic Preservation


Archeological Resources Protection Act



Maryland Historic Preservation Act



* U.S. Department of Transportation Act of 1966, Section 4(f)


Public Parks, Historic Sites, Recreational Areas and Wildlife Refugees

*Note that Section 4(f) only applies to federally funded transportation projects

Slide 13 Regulations & Laws (continued)

Regulatory Program

Agency Having Jurisdiction

Applicable Resource

Code of Maryland Regulations (COMAR) 26. 08. 02

Maryland Department of the Environment (MDE)


Stormwater Management Program

MDE delegated to Counties

Surfacewater Quality

Soil Erosion and Sediment Control Act

Soil Conservation Districts


Individual Well and Septics Program


Groundwater Quantity (withdrawl) and Quality (discharges)

Individual Onsite Sewage Systems and Private Wells

County Health Department

1970 Tidal Wetlands Act


Tidal Wetlands

1989 Nontidal Wetlands Protection Act


Nontidal Wetlands

Water Quality Certification Program (Section 401 of the CWA)



1972 Coastal Zone Management Act



1972 Federal Water Pollution Control Act, as amended by 1977 CWA (Section 404)

US Army Corps of Engineers (ACOE) and US Environmental Protection Agency (USEPA)


1899 Rivers and Harbors Act (Section 10)



Slide 14 Map Environmental Resources & Land Uses

  • Mapping Resources and Land Uses
    • Mapping environmental resources and land uses within the SCEA boundary provides a base from which many of the analytical methodologies can be performed. As highlighted in Module 4, land use mapping should be prepared for past, present and future time frames. This step must be conducted prior to performing the analyses.

Slide 15 Identify Methodologies & Conduct Analysis

  • Four basic SCEA methodologies:
    • trends analysis
    • overlay analysis
    • matrices
    • interviews

Slide 16 Identify Methodologies & Conduct Analysis (continued)

  • Integrating different SCEA methodologies for different resources can be used within a SCEA geographical boundary. For example:
    • Trends (qualitative analysis) for wetland losses in a watershed or subwatershed basin can be applied to the SCEA boundary to assess past, and possibly future, impacts to wetlands.
    • Overlays (quantitative analysis) of existing land use/land cover maps can be combined with future land use maps to assess future forest impacts. Note that it is possible to perform qualitative and quantitative analysis on the same resource.
  • These methodologies can be used together to assess cumulative effects to a single resource. For example:
    • For example, quantitative GIS and qualitative trend results from different years can be compared to identify past, present, and future resource loss trends.

Slide 17 Identify Methodologies & Conduct Analysis (continued)

Rationale for determining SCEA Methdologies

The methodologies to use for a particular resource should be based on:

  • availability of data (use existing, readily available data).
  • appropriateness of the data to the SCEA study area. Document what scale or geographical unit is available for each data source (i.e., state level, county level, census tract level, etc.)
  • ease of manipulating mapped data (overlays).
  • past or future impacts (overlays often cannot be used to assess past impacts because mapping of past resources may not be available).
  • impact of regulatory programs (especially regarding future impacts).

Slide 18 Identify Methodologies & Conduct Analysis (continued)

Trends Analysis

  • Trends analysis is the comparison of historic data to determine the historic loss and/or projected future resource impacts.
  • Reports and studies gathered from various sources may have important information on past effects to resources within the SCEA boundary. Note: Care must be taken in application of regional/statewide trends data to a smaller SCEA boundary.

Slide 19 Trends Analysis Process

SCEA Trends Analysis Process

Slide 20 Identify Methodologies & Conduct Analysis (continued)

Overlay Analysis

  • Quantitative or qualitative analysis which entails overlaying present and future land use maps over existing resources to determine present and future impacts. Can be used to determine past impacts, provided past resource mapping is available.
  • Overlays can be used to develop trends, which, in turn, can be used to project likely future effects. Remember to consider regulatory programs in projecting future impacts.
  • Sources of mapped data for determining past resource impacts include NWI/DNR wetlands mapping (wetlands), and aerial photography (forests, RTE species habitat, and active farmland).

Slide 21 Overlay Analysis

  • Overlay your future land use map upon an existing resource such as wetlands, floodplains, farmlands, woodlands and cultural resources. Identify where there is overlap between the resource and the future land use. The overlap between the resource and the future land use is your total impacted area.

Slide 22 Identify Methodologies & Conduct Analysis (continued)

See diagram for the Sample Overlay Analysis Process

Slide 23 Identify Methodologies & Conduct Analysis (continued)

Matrices Analysis

  • Matrices alone cannot quantify effects, but they are a useful means of presenting and manipulating quantitative results of trends analysis or overlay process.
  • Matrices can be used to show/illustrate trends of impacts to resources. For example, wetland impacts can be shown for pre and postregulation time frames to highlight the effects of regulatory programs.

Slide 24 Identify Methodologies & Conduct Analysis (continued)


  • Expert interviews are most useful where "hard" data is not readily available and may potentially be the most accurate and efficient method for assessing impacts to certain resources. Interviews can also be used to gather background data in the SCEA boundary.

Slide 25 Identify Methodologies & Conduct Analysis (continued)

Interviews (continued)

Expert Interview Sources

Information Provided

USGS Water Resource Specialists

groundwater quality problem areas, centralized sewer/water service areas, historic groundwater quality data, past and current stresses and impacts to groundwater resources.

County Health Dept Staff

USFWS and MD DNR Wildlife and Heritage Division

habitat requirements, sighting locations and critical habitat areas for R/T/E species and forest interior birds species, past, present and anticipated stresses and impacts to these species.

County Land Use Planners

existing and proposed centralized sewer/water service areas, future land use plans, open space proposals, demographic data and proposed developments.

USDA, SCS Soil Scientists/Agricultural Agents

trends in farmland acreage losses, information on farmland preservation programs.

County Engineers

trends in floodplain losses, information on County floodplain ordinances.

Local/County Historians

historic and archeological sites of local/county significance, past and current stress and impact to cultural resources.

Slide 26 How to reach conclusions

The SCEA should "count what counts." The SCEA "should not produce superficial analysis of a long laundry list of issues that have little relevance to the effects of the proposed action on the eventual decisions" (CEQ's Considering Cumulative Effects under the National Environmental Policy Act.)

Slide 27 How to reach conclusions (continued)

Be sure to document all secondary and cumulative effects. Concluding that there are secondary and cumulative effects is part of the overall SCEA process, so be sure to document when they occur. Keep the purpose of identifying and documenting, even if qualitatively, any of these effects at the forefront of your SCEA process.

Slide 28 How to reach conclusions (continued)

Factors to consider

  • Draw on experience of project team members to reach SCEA conclusions.
  • Document when there is not sufficient data to analyze effects on a particular resource.
  • Do not arbitrarily present data if no conclusions can be drawn.
  • Use tables (matrices) to help you interpret data.

Slide 29 How to reach conclusions (continued)

Additional Factors to Consider

  • Existing and proposed regulatory controls and how these controls will affect past, present and future impacts to resources.
  • Local, county and state planning initiatives. (Smart Growth, County Master Plans/Zoning)
  • Local preservation programs in place or proposed. (farmland preservation, open space preservation, etc.)
  • Future private development proposals and associated land use changes.

Slide 30 How to reach conclusions (continued)

Potential SHA SCEA Mitigation

If there are secondary and cumulative effects, it is important to balance impacts to resources with mitigation efforts.

Slide 31 Potential SHA SCEA Mitigation

  • Identification/development of potential mitigation measures for secondary/cumulative effects will result from consultation with appropriate resource agencies and local governments. When mitigation for a resource is warranted, the measures listed below are example of resource mitigation measures that may be considered.
    • Work with local/county government or resource agencies to develop/implement resource preservation plans.
    • Implement access controls that may minimize resource impacts


Exercise 1


Slide 32 Analysis Methodology used in MD 5 Transportation Improvement Project


Analysis Methodology





Water Resources















Forest Habitat





Endangered and Threatened Species





Active Farmlands





Historic & Archeological





Note: Interviews are generally used as a last resort

Slide 33 MD 5 Analysis Methodologies

Integrating Trends & Overlay Analyses

Trends analysis and overlays can be used together to assess past and future effects to the same resource. For the MD 5 project, trends were both extracted from existing published trends data and developed through overlay analysis of data sources.


  • Past wetland impacts (1972 to present) were assessed by review of statewide trends for the period of 1955 to 1978 as extracted from a USFWS publication.


  • Trends for 19811993 were developed by use of GIS (overlay) analysis.


  • Projection of past trends into the future with additional consideration of regulatory programs. Had a proper future land use scenario been developed, present wetlands could have been overlaid onto the future land use scenario to develop a conservative estimate of wetlands potentially impacted.

MD 5 Land Use Note: Please refer to the MD 5 example in Module 4.

Slide 34 MD 5 SCEA Analysis Methodologies (continued)

Description of Overlay Analysis

  • Past Impacts to Wetlands: Comparison of 1981 NWI mapping with 1993 DNR mapping.
  • Past Impacts to Forests: Comparison of 1973 and 1994 Land Use/Land Cover (LU/LC) maps from Maryland Office of Planning (MOP).
  • Future Impacts to Forests: Comparison of 1994 Forests per LU/LC maps with proposed development.
  • Past and Future Impacts to Active Farmlands: same as per Forests.
  • Future Impacts to Cultural Resources: Comparison of NRHP and Maryland Inventory of Historic Places site maps with proposed development (standing structures) and archeological site grid cells with proposed development (archeological resources).

MD 5 Land Use Note: Please refer to the MD 5 example in Module 4.

Slide 35 MD 5 SCEA Methodologies (continued)

Wetlands Integrating Overlay, Trends, & Matrix Analysis

MD 5 Land Use Note: Please refer to the MD 5 example in Module 4.

Slide 36 MD 5 SCEA Methodologies (continued)

See diagram for the Wetlands Possible Analysis Methodology following SHA SCEA Guidelines

Slide 37 MD 5 SCEA Analysis Wetlands

Comparison of 1981 NWI Wetlands (USFWS 1981) and 199394 DNR Wetlands

Wetland Classification



Net Difference

% Change


Estuarine Emergent





Estuarine Scrub Shrub



Total Vegetated Estuarine





Palustrine Emergent





Palustine Scrub Shrub





Palustrine Forested





Total Vegetated Palustrine





Combined Total Vegetated(Estuarine/Palustrine)





Palustrine Open Water










Slide 38 MD 5 SCEA Methodologies (continued)

Historic Properties Overlay Analysis

MD 5 Land Use Note: Please refer to the MD 5 example in Module 4.

Slide 39 MD 5 SCEA Methodologies (continued)

See diagram for the Historic Properties Possible Analysis Methodology following SHA SCEA Guidelines

Slide 40 MD 5 Transportation Improvement Project

See map for the National Register of Historic Places & Maryland Inventory of Historic Places

Slide 41 MD 5 Transportation Improvement Project (continued)

See map for the National Register of Historic Places & Maryland Inventory of Historic Places shown with Proposed Development

MD 5 Land Use Note: Please refer to the MD 5 example in Module 4.

Slide 42 MD 5 Transportation Improvement Project (continued)

National Register of Historic Places and Maryland Inventory of Historic Properties Summary of Secondary and Cumulative Impacts

Historic Resource



Zoned Area

Cumulative Impact

National Register of Historic Places





Maxwell Hall

NR240, CH196

Teagues Point Rd



National Register Eligible Sites (Identified through SHA's Historic Inventory)





William Chappelear Property


8780 Leonardtown Road


Yes *

Quaker Cemetery


NE Corner of Leonardtown Road and Lukes Lane


Yes *

W.H. Winstead Company Inc. Property



8275 Leonardtown Road


Yes *

Jesse M. Herbert Property


15610 Prince Frederick Road



Caroline Christ Farm


7761 Leonardtown Road



Maryland Inventory of Historic Properties

Old Fields Chapel


Prince Frederick Hughesville Rd. (231)



Herbert House


Prince Frederick Hughesville Rd. (231)



Benedict Road House


Prince Frederick Hughesville Rd. (231)



Patuxent City House


Brandywine Rd (MD 381)



Benedict Hill House, site (Higdon House)


Center Street



Prior's Cleave (The Heights, Truman's Place)


Wilkerson Road








Hawkin's Log House


Teagues Point Rd





Teagues Point Rd



St. John AME Church


Prince Frederick Hughesville Rd. (231)



* Historic Properties within the direct impacts area of the MD 5 project

Slide 43 MD 5 Transporation Improvement Project SCEA Conclusions

Potential Cumulative Effects

Factors Which Should Minimize Cumulative Effects

Surface Water

The cumulative effects of all proposed and/or potential developments (highway and nonhighway) to fisheries and water quality of the watershed within the SCEA boundary would be a continued degradation of water quality and watershed stability, especially to Gilbert Creek and Swanson Creek.

Comprehensive implementation of BMP's such as stream buffer protection and enhancement, may partially offset impacts to streams during and after development.


It is anticipated that the percentages of future wetland loss/conversion within the SCEA boundary will be less as compared to the past data trends.

This anticipated decline in future wetland loss is based on the notion that government regulatory programs will minimize wetland destruction in the future.


Implementation of the MD 5 Hughesville Transportation Improvement Project will not adversely affect regulated 100year floodplains. Future cumulative effects to floodplains are expected to be negligible to none.

This rationale is based on the current County floodplain regulations per the Flookplain Management Ordinance. (1992).

Slide 44 MD 5 Transporation Improvement Project SCEA Conclusions (continued)

Potential Cumulative Effects

Factors Which Should Minimize Cumulative Effects

Forest Habitat

The estimated potential cumulative forest habitat impact is 1,496 acres. It should be noted that this figure represents the maximum estimated forest impact that would occur, based on the proposed development known at this time.

The cumulative effects of this highway project coupled with other highway or nonhighway development projects would likely be that certain species of concern (such as FIDS) would decrease from substantial declines in their populations due to continued loss or fragmentation of habitat. Because of current regulations and standards that protect forests/forest buffer zones, some of the unknown and/or potential forest habitat areas within the proposed development sites will remain undeveloped.

Active Farmland

The estimated potential agricultural land impact due to potential cumulative effects is 334 acres of existing (1994) agricultural land.

This figure represents the maximum impact based on proposed development within the SCEA boundary.

Historic and Archeological Sites

Potential impacts to 3 NRHP eligible properties and 4 sites on the Maryland Inventory of Historic Properties. No archeological grids within the SCEA geographic boundary were identified in areas having valid preliminary subdivision plans.

Section 106 of the National Historic Preservation Act along with Section 4(f) of the Department of Transportation Act will minimize effects t NRHP eligible properties in the project's direct impact area.


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© 2000 Maryland State Highway Administration.
Last modified: Friday September 15, 2000.

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