New Study Points to ORV Activity as Primary Source of Air Pollution & New Paper on Roads & Wildlife Mitigation

Posted on March 24, 2010

New Study Points to Off-Road Vehicle Activity as Primary Source of Air Pollution

The San Luis Obispo (CA) Air Control Board released a study Feb. 22 on the impacts of off-road vehicle use at the Oceano Dunes and the resultant air pollution at the nearby Nipomo Mesa.

A preliminary study was undertaken in 2004 to determine what was causing high levels of air pollution — and potentially significant health problems for the people in this community. That study was somewhat inconclusive, and a second phase was begun in 2008 to hone in on the source of the pollution, with two primary targets: a ConocoPhillips refinery and the Oceano Dunes State Vehicle Recreational Area. It turns out the refinery was exonerated in the study, while the ORV area was fully implicated.

Here’s the crux excerpt from the Executive Summary:

  • “The airborne particulate matter (PM) predominantly impacting the region on high episode days does not originate from an offshore source.
  • Neither the petroleum coke piles at the ConocoPhillips facility nor agricultural fields or activities in and around the area are a significant source of ambient PM on the Nipomo Mesa.
  • The primary source of high PM levels measured on the Nipomo Mesa is the open sand sheets in the dune areas of the coast.
  • The open sand sheets subject to OHV activity on the SVRA emit significantly greater amounts of particulates than the undisturbed sand sheets at the study control sites under the same wind conditions.
  • Vegetated dune areas do not emit wind blown particles; the control site dunes have significantly higher vegetation coverage than is present at the SVRA.
  • The major findings resulting from detailed analysis of the diverse and comprehensive data sets generated during the Phase 1 and Phase 2 South County PM Studies clearly lead to a definitive conclusion: OHV activity in the SVRA is a major contributing factor to the high PM concentrations observed on the Nipomo Mesa.”


The executive summary goes on to say that the primary cause of the pollution is not from sand/dust being kicked up by ATVs directly, or ATV exhaust (though these are contributing factors), but instead the destruction of the soil crust and of the vegetation, both of which stabilize the dunes and significantly reduce windblown particulates.

The full study, entitled: South County Phase 2 Particulate Study is more than 100 pages long, and is available at the San Luis Obispo Air Pollution Control District website, along with several appendices. The release of the study was also reported in several news outlets.

New Paper on Roads and Wildlife Mitigation Available

This recent paper looks at some economic issues surrounding mitigation of road impacts.

ABSTRACT. Wildlife-vehicle collisions, especially with deer (Odocoileus spp.), elk (Cervus elaphus), and moose (Alces alces) are numerous and have shown an increasing trend over the last several decades in the United States and Canada.

We calculated the costs associated with the average deer-, elk-, and moose -vehicle collision, including vehicle repair costs, human injuries and fatalities, towing, accident attendance and investigation, monetary value to hunters of the animal killed in the collision, and cost of disposal of the animal carcass. In addition, we reviewed the effectiveness and costs of 13 mitigation measures considered effective in reducing collisions with large ungulates. We conducted cost-benefit analyses over a 75-year period using discount rates of 1%, 3%, and 7% to identify the threshold values (in 2007 U.S. dollars) above which individual mitigation measures start generating benefits in excess of costs. These threshold values were translated into the number of deer-, elk-,or moose-vehicle collisions that need to occur per kilometer per year for a mitigation measure to start generating economic benefits in excess of costs. In addition, we calculated the costs associated with large ungulate-vehicle collisions on 10 road sections throughout the United States and Canada and compared these to the threshold values. Finally, we conducted a more detailed cost analysis for one of these road sections to illustrate that even though the average costs for large ungulate-vehicle collisions per kilometer per year may not meet the thresholds of many of the mitigation measures, specific locations on a road section can still exceed thresholds. We believe the cost-benefit model presented in this paper can be a valuable decision support tool for determining mitigation measures to reduce ungulate-vehicle collisions.

The full cite is:
Huijser, M.P., J.W. Duffield, A.P. Clevenger,R.J. Ament, and P.T. McGowen. 2009.
Cost–benefit analyses of mitigation measures aimed at reducing collisions with large ungulates in the United States and Canada; a decision support tool.
Ecology and Society 14(2): 15. http://www.ecologyandsociety.org/viewissue.php?sf=41