Overview and Initiating the Environmental Impact Analysis and Assessment - Environmental Impact Analysis: Process and Methods - page 158

environmental analysis on viable alternatives and conserving the resources
available for the analysis. Common examples of fatal flaws used in alterna-
tive screening are:

r Exceedance of an environmental resource standard or criteria
(e.g., water-quality standards for one or more contaminants)
r Nonconformance with environmental permitting requirement
(e.g., involving the fill of more than the threshold area for a neces-
sary wetlands permit)
r Economically infeasible (e.g., more than double the estimated cost of
any other alternative or far in excess of available funds)
r Not implementable (e.g., not able to acquire the land or implement
within a mandatory schedule)
r Unacceptable level of anticipated impact to a critical environmental
resource, particularly as defined during scoping (e.g., destruction of
critical endangered species habitat)
r Technology not proven or accepted standard practice (e.g., if technol-
ogy failure results in catastrophic unacceptable consequences such
as for bridge construction methods or water treatment)

Side-by-side comparison is another accepted method of alternative screen-
ing for complex projects, plans, and programs. This approach requires an
early, generally qualitative, and relative evaluation of each alternative for each
critical factor, such as economic viability, implementability, impact to envi-
ronmental resources potentially at risk, etc. If an alternative is predicted to
have relatively severe adverse impacts or significant economic/engineering
limitations and there is another alternative that has less impact in these areas
and equal or greater attributes in all other areas, the inferior alternative can
be eliminated at the screening stage. For example, in the USCG DCR EIS alter-
native screening process, there were numerous initial alternatives for collect-
ing the spilled DCR on the vessel decks. One was an industrial grade mini
street sweeper stored on the ship's deck and another was a broom and shovel
combination. Preliminary analysis concluded that the mini street sweeper
would be very expensive; prone to maintenance issues; difficult to empty
while the ship was underway; require operator training; and relatively inef-
fective in collecting DCR around the hatches. In comparison, the broom and
shovel combination was cheap, required little training, could easily be emp-
tied, and was maintenance free. Thus the mini street sweeper was eliminated
at the screening stage and never subjected to detailed analysis.

4.5.4 Comparison and Selection of Proposed Action

The final selection of a preferred alternative is accomplished only after the full
evaluation of impacts because the comparison is centered on a comparison