Skip to content

Roseville Rail Yard Air Quality Study

The webpage is in chronological order. The most recent information is at the end.

Updated 2/15/12


On October 14, 2004, at the Placer County Air Pollution Control District’s (District) Board of Directors meeting, the District released findings of a study, the Roseville Rail Yard Study, conducted by the California Air Resources Board (ARB) on airborne particulate matter emissions from diesel-fueled locomotives at the Union Pacific J.R. Davis Yard in Roseville, California. The study was based upon locomotive diesel emissions at the facility and their related health risks from 1999 to 2000.

The District requested the study to:

  1. Determine the level of risk to the public from the emissions at the rail yard;
  2. What that risk meant in comparable terms to other sources of diesel emissions;
  3. What could be done to reduce the emissions, and thereby reduce the risks.

The ARB, in August 1998, had designated diesel particulate matter as a toxic air contaminant.

Diesel engines emit a complex mixture of air pollutants, composed of gaseous and solid material. The visible emissions in diesel exhaust are known as particulate matter, or PM, which includes carbon particles or "soot". The Study results indicated high concentrations of diesel PM in an area surrounding the Rail yard. The level of health risk associated with these PM emissions depends on length of exposure and proximity to the yard. Further questions regarding the Study can be found on the District Questions and Answers webpage.

October 14, 2004 APCD Board of Directors Meeting Information

On December 9, 2004 the District’s Board of Directors approved Resolution #04-21 authorizing the Chairman and the APCO to sign an Agreement with UPRR regarding mitigation measures and air monitoring for the Roseville Rail Yard. The Agreement that was signed has three main components:

  • Mitigation Plan
  • Grant Program
  • Monitoring Project

On April 14, 2005, the District’s Board of Directors received a briefing on the mitigation measures that were being evaluated for implementation at the rail yard. The mitigation measures were targeted for implementation over three calendar years (2005, 2006, 2007), and specific to the Agreement in §2A(iv) is the requirement that "progress reports towards achieving the emissions reductions specified in section A (i) shall be presented to the District Board and community by the end of the calendar years 2005, 2006, and 2007." The commitment is for at least a 10% reduction of particulate matter emissions by the end of 2007 from the baseline year (1999-2000).

April 14, 2005 APCD Board of Directors Meeting Information

On December 8, 2005, the District Board of Directors received a comprehensive review of District involvement with the rail related activities at the Roseville Rail Yard leading up to and including the current status of the various elements of our Agreement for mitigation and air monitoring with Union Pacific. The Board has been updated frequently regarding portions of elements, however this report combines all the information to date into one document.

December 8, 2005 APCD Board of Directors Meeting (Informational)

April 13, 2006 APCD Board of Directors Meeting Information

July 13, 2006 California Air Resources Board - Statewide Railroad Agreement Public Meeting

December 14, 2006 APCD Board of Directors Meeting Informations



April 5, 2007 - ALECS Final Report Released

April 12, 2007 - APCD Board of Directors Meeting Information

October 24, 2007 - The Supplemental Study of Elemental and Organic Aerosols Analysis for Roseville Rail Yard Monitoring Project

This report was prepared as an element of work sponsored by the United States Environmental Protection Agency via grant funding managed by the Placer County Air Pollution Control District. The purpose of this special study is to augment a more comprehensive elemental and organic analysis of aerosol samples collected during the summer of 2005 for locomotive diesel exhaust in Roseville, California. These samples were analyzed for particle sizes, metals, polycyclic aromatic hydrocarbons (PAHs), n-alkanes, sugars, and fatty acids. The results show that the particles collected by the samples were in the very fine to ultra-fine size fraction which is similar to diesel truck results presented in the literature. And the samples had higher concentration of PAHs than diesel truck emissions that are the basis of many risk assessments. The complete report can be downloaded below.

August 14, 2008 - APCD Board of Directors Meeting Information

October 9, 2008 - APCD Board of Directors Meeting Information

August 20, 2009 – APCD Board of Director Meeting Information

On August 20, 2009, the District Board of Directors approved a contract with Sierra Research, Inc. to conduct a project which will evaluate computer modeled diesel particulate matter (DPM) levels around the Union Pacific Railroad (UPRR) - Roseville Railyard in comparison to monitored DPM levels. This follow-up research study is based upon the Roseville Railyard Air Monitoring Project (RRAMP). The RRAMP was a four-year (2005-2008) air monitoring study of the air pollutant impacts emanating from the UPRR Roseville Railyard facility. The proposed project results will help to quantify the level of potential bias in the air dispersion model for future modeling analysis and provide useful information regarding the interpretation of data collected in the RRAMP.

December 10, 2009 – APCD Board of Director Meeting Information

On December 10, 2009, the District Board of Directors received a comprehensive final report for the Roseville Railyard Air Monitoring Project (RRAMP) along with the final updates of the 2004 UPRR/PCAPCD Agreement (Agreement) for mitigation plan, and the grant program with Union Pacific. This report is the culmination of four years of air monitoring and analysis of the data collected from the JR Davis Union Pacific Railyard site located in Roseville and the summary of mitigation measures and the grant program. The results of RRAMP confirm that mitigation measures agreed to by UPRR in a 2004 Agreement have been met.

October 13, 2011 - APCD Board of Director's Meeting

On October 13, 2011, the APCD Board were presented with a final report on the evaluation of air dispersion modeling results compared to air monitoring concentration measurements at the JR Davis Union Pacific Rail Yard. The complete report can be found at this link: UPRR Modeling Evaluation Study. The Board memo and accompanying documents can be found on the Board of Directors page.


Useful Links


To read a PDF document, you need the free Adobe Acrobat Reader PDF software on your computer. If you don't have it installed, you may download it from the Adobe website. Adobe provides detailed instructions on downloading and installing the free reader.

Top