Origins and development - Introduction to Environmental Impact Assessment - page 33

A “lead agency” is designated that co-ordinates the EIA process. The lead agency first
determines whether the proposal requires the preparation of a full EIS, no EIS at all, or a
“finding of no significant impact” (FONSI). This is done through a series of tests. A first
test is whether a federal action is likely to individually or cumulatively have a significant
environmental impact. All federal agencies have compiled lists of “categorical
exclusions” which are felt not to have such impacts. If an action is on such a list, then no
further EIA action is generally needed. If an action is not categorically
Figure 2.1 Process of EIA under
NEPA. (Adapted from Legore 1984.)
excluded, an “environmental assessment” is carried out to determine whether a full EIS
or a FONSI is needed. A FONSI is a public document which explains why the action is
not expected to have a significant environmental impact.