Are environmental impact statements imperfect

[Gary Anweiler]

This is kind of like asking if reality is real.  Depends eh

As someone who DID a lot of impact assessments (mainly vertebrate) in my
time - and as concientiously as I could - I can say this.  It IS possible
for a contractor to obtain much of the knowledge he/she needs to work on a
specific project (i.e. I would have contacted whoever I could find who was
considered an expert on a particular issue or organism and asked for their
input - read everything about the organism in question I could locate - and
put together a plan that addressed the concerns to be investigated. 
HOWEVER, I don't think it is very possible to not be somewhat biased
towards the view of whoever is funding the project.  There are, after all,
many ways to look at and interpret data - especially when one is working
under time, funding and other constraints.  At best I think the limitations
of a particular study can be pointed out in the report. I think many
consultants do the best they can - otherwise they would soon lose any
credibility.

I am sure all this varies greatly with jurisdiction and other factors. 
Bottom line is I am no longer doing that work.  Got tired of being the last
one out before the bulldozers pulled in.