Assignment No. 5: Thresholds of Significance

Scope

Prepare a memorandum for your supervisor and team mates' benefit, using appropriate evidence, scientific methodology, and supporting arguments to establish thresholds of significance for each of the indicators you studied in Assignment No. 3, Indicators and Indices.

This memorandum must allow an educated but uninformed reader to understand the proposed threshold(s) of significance associated with the resource under study and compare the indicators for your particular setting to these thresholds.  Each member of the project team must study different indicators (the same ones you worked on earlier) and produce an individual report.
 

Preparation of the Document

For each of the indicators studied in Assignment No. 3, consult the literature and propose thresholds of significance.  A given indicator may be subject to several thresholds (e.g., warning level, alert level, serious harm level); in this case, indicate clearly which level you propose to use as a threshold for determining significant effects or impacts, as described under NEPA and CEQA.  The others may be used later to help compare and rank alternatives.

Thresholds of significance may be based on legal enforceable standards (e.g., National Ambient Air Quality Standards  or NAAQS, Federal Drinking Water Standards), on accepted professional recommended standards (e.g., NIOSH Recommended Exposure Limits or RELs), on known damage levels (e.g., toxicity levels established by scientific studies), etc.  As mentioned above, it is not infrequent to have several possible thresholds applying to a single indicator.  Discuss the various possible thresholds, citing your sources, and explain your reasoning clearly in picking a threshold of significance for the indicator.  Discuss the sensitivity and value of the proposed thresholds of significance.

Compare the values obtained for your particular environmental setting versus each indicator (Assignment No. 3) to the thresholds of significance you are proposing in the current memorandum.  Discuss the implications for your setting and project.
 

Format

Your document should be 4 to 6 pages long (1.5 line spacing in a reasonable 10 pts to 12 pts font), excluding any tables, figures, and appendices, and presented in memorandum format.  Be clear, concise, and specific.  Style, grammar and spelling will be considered.  This is an individual assignment.

Include at least:
 

  • memorandum heading, including date, author, subject, and routing information
  • identifying headers and footers, including page numbers
  • summary and explanation of the information presented
  • methodology and reasoning used in establishing the proposed thresholds
  • short conclusion evaluating the sensitivity of the proposed thresholds and implications for your project
  • appropriate tables, figures and supporting appendices
  • list of references
  • supporting evidence (in appendix)
    •


    Due date: Monday, March 29, 1999 (by 5:00 PM).

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