Conducting the Environmental Impact Analysis and Assessment - Environmental Impact Analysis: Process and Methods - page 191

r Management of fly ash (i.e., waste from coal fired plants)
r Fish passage for hydroelectric generation
There have been standard techniques of impact prediction for other indus-
tries and actions, such as wastewater treatment (as described in Section 5.3.3),
transportation, and land-use planning. When embarking on an environmental
analysis of a project, plan, or program in one of these areas, review of impact
prediction for similar actions can result in not only efficiency but also improved
technical quality of the analysis, and use of previously successful impact predic-
tions can support acceptance among stakeholders. In order to successfully apply
previously employed impact prediction methods, the environmental analysis
team, relying on appropriate expertise within the team, must determine the
applicability of previous methods to the action under consideration, scale the
approach to the current action, and then develop and quantify as appropriate
the input for the various variables in the impact prediction procedure.
Evaluation of impacts centers on predicting what the environmental con-
ditions would be if a particular action were taken. Similar to predicting the
weather (but hopefully with more success and public acceptance), impact
prediction frequently involves models. Such models can range from the most
simple (conceptual impact models, Figure 5.10) to very sophisticated math-
ematical models such as the one used in the Boston Harbor Cleanup EIS (see
Section 5.3.5). The models can also be empirical and based on measurement of
past similar actions as in the USCG DCR EIS (see Section 5.3.4). In most disci-
plines, models are available for predicting future conditions given a set of input
values, and the experts on the environmental analysis team and/or TAC should
be familiar with the models available and their appropriate application to spe-
cific situations. However, having the model is the easy part of impact prediction,
and the hard parts, identifying and providing the input variables, interpreting
the results, and understanding the uncertainty require the hands-on participa-
tion of the environmental analysis team members with appropriate expertise.
It is beyond the scope of this topic, or in fact any topic, to even attempt an
identification of models or other impact prediction methods applicable to all,
or even many, specific combinations of environmental conditions, types of
actions, and locations. However, the general approaches summarized above
can be applied by environmental professionals with the appropriate techni-
cal expertise to most specific situations. Case studies are presented for the
USCG DCR management EIS and the Boston Harbor Cleanup, which can
serve as food for thought in designing impact prediction approaches for
other actions and environmental resources. Common and critical to each of
the case studies and methods presented earlier is the use of significance cri-
teria; so once predicted the impacts and other changes in existing conditions
can be judged, compared, and used as input to decision making. As dis-
cussed immediately below, a comprehensive understanding of impact sig-
nificance criteria is essential to adapting expertise in various environmental
disciplines to successful, meaningful, and useful impact prediction.