USDA Forest Service

Pacific Southwest Research Station


Pacific Southwest Research Station
800 Buchanan Street
Albany, CA 94710-0011

(510) 559-6300

United States Department of Agriculture Forest Service. USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.

Sources of Particulate Matter

Atmospheric deposition is a major contributor to the decline in Lake Tahoe's water clarity. Understanding the sources contributing to air pollution in the Lake Tahoe basin is crucial for determining the impact of atmospheric deposition on water quality in the lake.

Full title: Lake Tahoe source attribution study: receptor modeling study to determine the sources of observed ambient particulate matter in the Lake Tahoe basin

This project was completed in December 2009. The principal investigators have provided the attached report and appendices for download:

LTADS SitesLead Researchers: Johann Engelbrecht and Alan Gertler, Desert Research Institute; Tony VanCuren, University of California, Davis


  1. Analyze the previously collected ambient results (LTADS) to distinguish subsets of site and seasonal data.
  2. Use multivariate statistical procedures such as principal components analysis and factor analysis to distinguish chemical species of relevance within the measured ambient data set.
  3. From previous studies and the DRI source profile data base, compile a set of chemical profiles applicable to the receptor modeling of the LTADS ambient results.
  4. Apply the chemical mass balance (CMB) model to the LTADS ambient and source profile data, to assess the source attribution to particulate matter (PM) in the Lake Tahoe basin.

Sites: Two-week samplers at 5 sites and MiniVol samplers at 13 sites on buoys/piers and on land

Timeframe: October 2007 through June 2010 (2.5 years)


  1. Data analysis with graphical representations of the most important species, seasonal trends over the sampling year, and spatial similarities and differences among the sites.
  2. A set of chemical source profiles applicable to the receptor modeling of the LTADS ambient results.
  3. A report delineating the polluting sources and their modeled contributions to PM in the ambient air, to better inform a management strategy for reducing air pollution.
Last Modified: Mar 28, 2013 02:52:07 PM