4.0 CUMULATIVE IMPACTS - Sacramento District - U.S. Army

4.0 Cumulative Impacts
that is not consistent with the intensity of development presented in a General Plan or if
it was not previously accounted for, it is assumed that the emissions associated with that
development are unaccounted for in the SIP, which could hinder the region’s ability to
come into compliance with State and federal air pollutant standards. Although many
criteria air pollutants within the Sacramento Valley Air Basin were accounted for in the
SIP, current growth forecasts for the Roseville area with approval of the Proposed Action
would be higher than what was projected when the existing plans were prepared.
Therefore, emissions associated with operation and occupancy of the Proposed Action
and buildout of cumulative development would cause direct adverse effects to the
region’s ability to achieve compliance with air quality standards.
Compliance with the City’s Transportation Systems Management Ordinance and
implementation of Mitigation Measure AQ-2, which requires implementation of a
number of measures to reduce vehicular traffic and energy use, would reduce the
amount of emissions generated by the Proposed Action. The Proposed Action would also
be subject to a variety of policies that would promote the use of alternative forms of
transportation and pedestrian access to commercial and office uses within the project site.
However, because the operational air emissions associated with the Proposed Action are
not accounted for in regional air quality attainment plans, even with mitigation, the
emissions would be considered significant and the Proposed Action would make a
significant contribution to the cumulative impact on regional air quality.
CO Concentrations
Background CO concentrations in Roseville are low, and despite anticipated increases in
traffic volumes, future roadside CO concentrations are expected to decrease from existing
concentrations due to improved fuel combustion efficiency (City of Roseville 2010a).
Therefore, the Proposed Action, in conjunction with buildout of reasonably foreseeable
development in the area, would have a less than significant effect related to CO
concentrations.
All Alts. All alternatives would result in some development on the project site or the Alternative 4
site. The intensity of development would be generally comparable to, or slightly less
than, that under the Proposed Action, and the contribution of the alternatives to
cumulative effects on air quality would be generally similar to that of the Proposed
Action. Therefore despite mitigation, operational emissions from all alternatives would
result in a significant contribution to the cumulative impact on air quality.
Impact Sciences, Inc. 4.0-29 Sierra Vista Specific Plan Draft EIS
USACE #200601050 July 2012