(b) For each EQ resource attribute, planners 

 should specify one or more indicators. The number 

 of indicators specified should be sufficient to ade- 

 quately measure or otherwise describe changes in 

 the quantity or quality of an EQ attribute. Since indi- 

 cators are the primary' factors that will determine 

 the amount and level of detail of information collec- 

 tion, care must be exercised to ensure that the 

 number of indicators is not so large that information 

 requirements are unreasonably demanding. See 

 3.2.1 for examples of indicators. 



(c) For each indicator, planners should specify a 

 unit of measurement or description. Units will usual- 

 ly be readily identifiable from the nature of an indi- 

 cator. For example, the indicator "area" could be 

 described in terms of the unit "acres" or "square 

 miles." See 3.2.1 for other examples of units. 



(d) For each indicator, planners should specify a 

 guideline. 



(1) Guidelines should be based on institutional, 

 public, or technical recognition. Examples of institu- 

 tional guidelines are State air and water quality 

 standards and the access criterion for Federally 

 designated wild rivers. Examples of guidelines 

 based on public recognition are preservation of a 

 locally valued natural viewscape and the protection 

 of a regionally popular reach of white water river. 

 Examples of guidelines based on technical recogni- 

 tion are a minimum dissolved oxygen concentration 

 of five parts per million for brown trout and the 

 preservation of an archeological site's association 

 with an important event. 



(2) The decision to use a guideline based on 

 technical or public recognition instead of an existing 

 institutional guideline, or to use one institutional 

 guideline instead of another, should be justified. Ex- 

 amples of this situation are the choice of a more 

 restrictive suspended solids standard based on a 

 recent limnological study (technical recognition) 

 over a less restrictive State suspended solids 

 standard (institutional recognition); and the choice 

 of a more restrictive, locally established noise level 

 standard over a State or federally established 

 standard. 



(3) Planners should recognize recent and antici- 

 pated future changes in guidelines based on chang- 

 ing institutional, public, and technical concerns. The 

 phased implementation of State water quality 

 standards developed pursuant to Pub. L. 92-500 is 

 an example of a change that could be anticipated. 



(4) Planners should also recognize that guide- 

 lines may differ for a given indicator among local- 

 ities and regions. For example, air quality standards 

 vary among the States and often vary for areas 

 within a given State. 



(5) Guidelines that are stated in a word or phrase 

 may, in some cases, be translated into a number. 



(i) For example, the guideline "protection of a 

 popular reach of white water river" could be restat- 

 ed in terms of the physical dimension of the reach, 

 such as "two miles," that provides a specific work- 

 ing definition of "protection". 



(ii) Examples of words that may provide a basis 

 for a guideline are enhancement, improvement, 

 preservation, protection, conservation, mainte- 

 nance, creation, restoration, repair, and rehabilita- 

 tion. 



(6) Guidelines may be expressed as a single 

 level (example: habitat suitability index of 1.0); as a 

 range between two levels (example: pH between 

 6.5 and 8.0 for fish); or as a threshold level (exam- 

 ple: total dissolved solids not greater than 500 

 parts per million). 



(7) In cases where several seemingly conflicting 

 guidelines have been proposed, planners should at- 

 tempt to specify a single guideline by determining 

 the specific reasons why each proposed guideline 

 is desirable. 



(i) For example, the Blue River has an indicator 

 "water flow," which is described in "cubic feet per 

 second (cfs)" units; a local agricultural cooperative 

 that uses the river for irrigation water proposes a 

 guideline of "X cfs;" a homeowners association 

 that enjoys the view of the river proposes a guide- 

 line of "Y cfs;" and a fishenes biologist proposes a 

 "Z cfs" based on the needs of the river's anadro- 

 mous fish populations. 



(ii) In this example the "Y cfs" guideline would be 

 appropriate for the river's visual aesthetic attribute, 

 but would not be used for its ecological or cultural 

 attributes. Similarly, the "Z cfs" guideline would be 

 appropriate for the river's fishery ecological attri- 

 bute. The "X cfs" guideline would not be appropri- 

 ate for EQ evaluation since it is not related to an 

 EQ attribute. 



(e) For each indicator, planners should specify a 

 tectinique for measuring or otherwise describing 

 current and future conditions of the indicator in 

 terms of the indicator's specified unit. Table 3.4.4 

 lists examples of techniques currently used in water 

 resources planning. Regardless of the technique 

 used to measure or othenwise describe an indicator, 

 agencies should ensure the professional and scien- 

 tific integrity of techniques and their resultant analy- 

 ses, as required by the CEO NEPA regulations (40 

 CFR 1502.24). 



(f) Although the parts of the evaluation frame- 

 work are presented in a specific order, planners 

 may, after first selecting indicators, select units, 

 guidelines, and techniques in any sequence 



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