Conducting the Environmental Impact Analysis and Assessment - Environmental Impact Analysis: Process and Methods - page 210

the population from any change in DCR management practices and
no adverse impact from invasive mussels in Lake Superior.
r Zebra and quagga mussels are present in Lakes Michigan and Huron
currently, but at least in some areas of the lakes they may not be at
maximum density or distribution. No specific factor limiting mussel
distribution or density has been identified and suitable attachment
substrate cannot be ruled out as one of the limiting factors. Thus
DCR discharge has the potential to increase the quality and extent
of suitable mussel habitat in these lakes. However, the natural cover-
ing of DCR with native sediment, limited mobility of adults, and the
presence of DCR on the lake bottom from over 100 years of dry cargo
transport indicate that any increase of mussel density or distribu-
tion resulting from the continued discharge of DCR would produce
only a minor, or insignificant impact from invasive mussels on the
aquatic ecosystem of Lakes Michigan and Huron.
Using the information developed from the invasive mussel investiga-
tions, the USCG concluded that the insignificant impact prediction of mussel
population expansion from ongoing DCR management practices in Lakes
Michigan and Huron was acceptable. The studies demonstrated that, at least
in the short term, the continuation of the current practice would not result
in the increase in invasive mussels to the extent that there would be any
ecosystem-wide adverse impacts. This decision did incorporate a degree of
judgment but the conclusion is based on hard scientific evidence and more
than fulfilled the “hard look” mandated by NEPA, as discussed in Chapter 3,
Section 3.7. The hard look at invasive mussel impact provided in the DCR EIS
differs from other approaches as summarized for the Hughes River environ-
mental impact analysis in the following section.
5.3.4.3 Comparison of DCR Impact Prediction to
North Fork of the Hughes River EIS
One might take issue with the interpretation of the invasive mussel investiga-
tions or the DCR management rule-making decision reached by the USCG.
But it is unarguable that the USCG took a “hard look” at the impacts related
to the invasive mussel situation before they issued the final EIS or rendered a
decision on the DCR management rule making. Thus they met the impact pre-
diction of NEPA mandate as interpreted by the courts. This was not the case
in another proposed federal action with potential invasive mussel impacts.
In the early 1990s, after years of consideration, the Natural Resources
Conservation Service (NRCS) and the U.S. Army Corps of Engineers pro-
posed a dam on the North Fork of the Hughes River in a mountainous area of
northwestern West Virginia (project history and court decision presented in
Hughes River Watershed Conservancy v Glickman , 81 F.3d 437, 445 [4th Cir. 1996]).