The Owens Lake Scientific Advisory Panel (OLSAP) of the National Academies of Sciences, Engineering, and Medicine will evaluate off-lake sources of airborne dust in Owens Valley, California. Off-lake dust sources are those that are located at elevations above the 3,600 ft regulatory shoreline of Owens Lake. OLSAP will focus on those sources for which available data indicate they are potentially significant contributors to high PM10 concentrations in the Owens Valley Planning Area (OVPA). (PM10 refers to airborne particulate matter with an aerodynamic diameter of 10 micrometers or smaller.)

As part of its assessment, and to the extent sufficient data are available, OLSAP will summarize the overall nature and character of off-lake sources. The majority of the local off-lake sources fall within 2-3 km from the shoreline as used in the air modeling conducted for the 2016 State Implementation Plan (SIP) for achieving and maintaining the National Ambient Air Quality Standards (NAAQS) in the OVPA. In addition, the panel will address the following aspects with respect to off-lake dust sources:

• Develop a summary of previous research, studies, and available information on off-lake dust sources in the OVPA that synthesizes the overall character of off-lake dust sources, including (but not limited to):

A. Physical setting and other characteristics, such as geomorphological features.

B. Extent and distribution of off-lake sources.

C. PM10 impacts of off-lake sources, with impacts defined as causing or significantly contributing to exceedances of the PM10 NAAQS in the OVPA.

D. Past and expected future changes in off-lake dust sources over time. Consideration of changes may include emissivity, number, extent, and distribution of off-lake sources.

• Describe the origin of regulatorily significant off-lake dust sources and how they developed over time.

• Describe potential options and recommendations to better characterize, monitor, and track changes in the PM10 contributions of off-lake sources to exceedances of the PM10 NAAQS in the OVPA.

• Describe possible dust control measures that could be applied to significant off-lake sources, with consideration of feasibility.

• If appropriate, discuss the applicability of U.S. EPA’s Exceptional Events Policy for excluding air quality monitoring data affected by dust emissions from off-lake sources from use in determinations of whether the OVPA was in compliance with the NAAQS.