Pacific Southwest Research Station

Using Fingerprinting to Determine Sources of Highway Sediment

This study will use chemical fingerprinting to identify and map highway and road sources of fine sediment that is entering and has historically entered Lake Tahoe through stormwater runoff and streams. Fingerprinting will use a full suite of major ions and trace elements, including rare earth elements (REEs), strontium (87/86), and lead (206/207/208) isotopes.

Full title: Determining sources of highway runoff fine sediment in stormwater, streams, and Lake Tahoe using fingerprinting techniques

Proposal [pdf]

Lead Researchers: Jim Thomas and Alan Heyvaert, Desert Research Institute

Goals

1. Determine the sources of fine sediment in highway and roadway runoff.
2. Distinguish relative contributions from traction sand, vehicle wear, tire wear, road surface wear, vehicle emission particulates, road shoulders, and slope cuts in highway and roadway runoff that reaches Lake Tahoe.
3. Develop a geographic information system (GIS) representation for highways and roadways showing high, medium, and low areas of potential fine sediment yield for highway runoff.

Methods

1. One hundred and twenty source samples will be analyzed for "fingerprinting" source materials. Some of the highway and road shoulder fine sediment will be obtained from the Tahoe Science roadway dust project.
2. Collect and analyze water samples from highway and road runoff, including, stormwater flowing directly into Lake Tahoe, streams entering Lake Tahoe, and Lake Tahoe itself.

Timeframe: July 2008 through June 2010 (2 years)

Products

1. Fingerprinting data for source material, water samples, and lake cores
2. A GIS tool that identifies highway and road sections throughout the Tahoe basin that have high, medium, and low potential to deliver fine sediment in highway runoff
3. Quarterly progress reports and final project report