Draft Environmental Impact Report - California Off Highway Vehicle ...

3.2 Air Quality
the project area, the congestion could result in a localized CO concentration (often referred to as a
“CO hotspot”) that could exceed NAAQS or CAAQS for this pollutant, and concentrations could
reach unhealthy levels at nearby sensitive land uses such as residences.
Localized CO concentrations near roadway intersections are a function of traffic volume, speed,
and delay. Transport of CO is extremely limited because it disperses rapidly with distance from the
source under normal meteorological conditions.
Butte County AQMD recommends using a screening approach to determine whether long‐term
project operations would have the potential to violate the CO standard (Butte County AQMD
2008). Based on Butte County AQMD guidance, the General Plan would result in a significant CO
concentration if:
a traffic study for the project indicates that the peak‐hour LOS on one or more streets or at
one or more intersections would be reduced to LOS E or F or
a traffic study indicates that the project would substantially worsen a traffic delay
(i.e., increase delay by 10 or more seconds) on one or more streets or intersections that are
already at a LOS F.
The traffic impact study prepared for the General Plan (see Section 3.1 of this DEIR) states that:
Traffic generated by implementing the General Plan is projected to have a very minor
effect on operations at each of the study intersections during either the weekday or
Saturday peak hours (Table 3.1­11). Satisfactory LOS C or better operations are
projected to continue at all locations with the exception of the southbound approach
at the SR 162/Larkin Road intersection. Increased traffic at this location is projected
to result in LOS F at the southbound approach under [future] weekday conditions with
or without the addition of project­generated traffic. All other approaches to this
intersection are projected to experience satisfactory LOS A or B delays. An analysis of
forecasted volumes in comparison with California Manual of Uniform Traffic Control
Devices for Streets and Highways thresholds (Warrant 3, Figure 4C­4) (Caltrans
2010) indicates that the intersection would not warrant the installation of a traffic
signal. A peak­hour volume of 87 vehicles is projected at this approach (Figure 3.1­11),
while a threshold of 190 vehicles would be required to consider the installation of a
traffic signal.
Because the projected LOS F volume would not be a result of implementing the General Plan, but
rather, would occur with or without the addition of project‐generated traffic, and because traffic
generated by implementing the General Plan is projected to have a very minor effect on traffic
operations, the project would not be responsible for creating a CO hotspot and this impact would
be less than significant.
Clay Pit State Vehicular Recreation Area
Draft EIR 3.2-17 February 2012