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

3.2 Air Quality
may otherwise drive outside the area to other OHV recreation facilities, or who may operate OHVs
in non‐designated areas in the county. No other SVRAs are located within 80 miles of Clay Pit
SVRA and 4x4 recreationists routinely drive over 100 miles to reach recreation areas outside of
Butte County. By offering new on‐site facilities such as a 4x4 obstacle course and motorcycle
tracks, local user groups would be less likely to drive as far to participate in these activities, thus
reducing potential vehicle emissions.
TABLE 3.2­6. NET OPERATIONAL AIR EMISSIONS DURING A PEAK WEEKEND FOLLOWING
CONSTRUCTION OF VISITOR FACILITIES ENVISIONED IN THE GENERAL PLAN
(APPROXIMATELY 2017)
Area Sources
Mobile Sources
Source
Emissions (lbs/day) 1
ROG NOX CO PM10 PM2.5
Subtotal Area Sources 0.02 0.02 0.02 0.00 0.00
Visitor Vehicles 2 1.86 2.61 29.71 27.42 3.26
OHVs 17.52 0.69 85.17 ‐15.76 3 ‐1.55 3
Site Maintenance Activities
Subtotal Mobile Sources 21.26 3.30 114.88 11.66 1.71
Subtotal Site Maintenance 0.67 4.34 4.55 3.05 0.79
Total emissions 21.95 7.66 119.45 14.71 2.50
Butte County AQMD significance threshold 4 25 25 – 80 –
Exceeds project threshold? No No N/A No N/A
Notes: Butte County AQMD = Butte County Air Quality Management District; lbs/day = pounds per day; CO = carbon
monoxide; NOX = oxides of nitrogen; PM10 = particulate matter 10 microns in diameter or less; PM2.5 = particulate
matter 2.5 microns in diameter or less; ROG = reactive organic gases; SOX = oxides of sulfur.
The total emissions estimates shown are the highest values that would occur during the year. Totals may not add up
to individual values because the highest emissions for a pollutant from both area and mobile sources may not occur
in the same season.
Refer to Appendices B and C of this DEIR for detailed assumptions and modeling output files.
1 Emissions modeled for annual conditions for Butte County using the URBEMIS2007 (Version 9.2.4), EMFAC2007,
and OFFROAD2007 computer models.
2 Visitor vehicle PM10 emissions from travel on unpaved roads were calculated separately from URBEMIS2007
(Version 9.2.4) to provide a more precise estimate of visitor VMT onsite and on unpaved roads. Assumes an
average trip length of 50 miles on paved roads and 0.5 mile on unpaved roads (at Clay Pit SVRA) since, based on
existing data 80% of visitors reside within 50 miles of the Clay Pit SVRA.
3 PM10 and PM2.5 OHV emissions take into account on‐site watering of the tracks (up to 5 times per day) at Clay Pit
SVRA that would occur under the Clay Pit SVRA General Plan. The reduction in PM emissions from watering would
apply to existing trips under 2017 conditions.
4 Corresponds to Butte County AQMD’s Level B threshold Butte County AQMD 2008:2‐2.
Source: Data modeled by AECOM in 2011
Clay Pit State Vehicular Recreation Area
February 2012 3.2-14 Draft EIR