Which neighbors are at greatest risk for odor and dust?

Wind direction and speed affect dust and odor risk. The first step is to identify the prevailing downwind directions. Different wind speeds cause different challenges. High wind speed increases risk for dust, while low wind speeds and cooling conditions (typically, nighttime conditions) increase the risk of odor impacting neighbors.

Information on the prevalence of wind direction is available for many locations and may be illustrated as a ‘wind rose’. The visual presented in Figure 1 shows downwind direction – where dust and odorous air are most likely to go – using the same rose concepts; the longer the petal, the more often air will head in that direction (Figure 1). Frequencies are summarized for 21 Nebraska locations.

Wind Rose Graphic
Figure 1. Downwind direction frequency for assessing dust risk (left) and odor risk (right, low wind speed) for West Point. Reference: High Plains Climate Center wind data for 1996-2012. Note that this graphic illustrates only the direction of risk, not separation distance. Tools such as the Nebraska Odor Footprint Tool provide information on separation.

Downwind direction frequency can be used to evaluate sites for a new or expanding livestock facility – as dust and odor risk depend largely upon downwind direction frequency and separation distance. Note for some locations that higher-risk directions for dust (all wind speeds) may differ from those for odor (low speeds). Using these plots along with satellite images or plat maps can assist in initial screening of facility locations. Considering alternative sites along a line 90 degrees from the prevailing winds (East and West for Figure 1) can reveal preferred alternative building sites.