Chapters 1 - U.S. Fish and Wildlife Service

5 Environmental Consequences
5.1 Introduction
This chapter provides an analysis and evaluation of the environmental consequences of
implementing the alternatives described in Chapter 3. Impact evaluation has been conducted for
each aspect of the environments described in Chapter 4 – Refuge Resources, including physical,
biological, cultural, and socio-economic resources. The adverse and beneficial effects of each
alternative are generally described under two main action categories – Wildlife and Habitat
Management (including habitat enhancement/restoration) and Public Use. Cumulative effects on
the environment of implementing the three alternatives are presented in Section 5.8.
5.2 Effects to the Physical Environment
Topics addressed under the physical environment section of this document include direct and
indirect effects to topography, visual quality, geology and soils, mineral resources, agricultural
resources, hydrology, and water quality, climate change and sea level rise, air quality, and
greenhouse gas emissions.
The criteria used in this document to determine if a particular impact represents a significant
adverse effect are present below for each topic.
Topography – An adverse topographic effect is considered significant if grading or other
land altering activity is proposed in a highly scenic area or would alter a locally or
regionally important topographic landmark, or if any proposed activities would
substantially alter the existing landform.
Visual Quality – An adverse visual impact would be considered significant if a proposal
would substantially alter the natural landform or block public views to a public resource
such as the Pacific Ocean or Anaheim Bay.
Geology/Soils – Impacts related to geology and soils would be considered significant if a
proposed action would trigger or accelerate substantial slope instability, subsidence,
ground failure, or erosion affecting onsite facilities or adjacent facilities, such as roadway
embankments and bridge abutments. Impacts would also be considered significant if any
proposed structures would be susceptible to geological hazards, such as liquefaction,
settlement, ground rupture, or lateral spreading.
Mineral Resources – Impacts to mineral resources would be considered significant if a
proposed action could result in the loss of availability of a known mineral resource that
would be of value to the region.
Agricultural Resources – A significant adverse effect on agricultural resources would occur
if a proposed Refuge action would impact adjacent Prime Farmland or cause the
conversion of Prime Farmland to non-agricultural uses.
Draft Comprehensive Conservation Plan/Environmental Assessment 5-1