USDA Forest Service

Chemistry of Lakes, Streams, Bulk Deposition, and Ambient Ozone Monitoring on and near National Forests

USDA Forest Service Air Resource Management
Natural Resources Research Center
2150 Centre Ave., Bldg. A
Fort Collins, CO 80526
(970) 295-6012

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Welcome to the Air Resource Management Surface Water, Bulk Deposition, and Ozone Data Website


The USDA Forest Service is responsible for protecting watersheds on the national forests from the adverse effects caused by atmospheric deposition.  Thus, the Forest Service Air Program has been actively inventorying and monitoring hundreds of lakes and streams since the early 1980’s. We also have obtained hourly ambient ozone data from hundreds of monitoring sites across the United States in locations that may be representative of the national forests. Our purposes have been to characterize:
1) Watersheds (lakes and streams) that are sensitive to the effects of acidic deposition and/or base cation depletion.
2) Long term trends in surface lake chemistry.
3) Ozone concentrations within the National Forests especially those that are unhealthy for people.

We refresh the water database on or about the first of every month, while the ozone data are updated once each year.


We use the water data to help us determine whether changes in lake and stream chemistry are due to: changes in air quality, certain sources of air pollution, changes in weather, climate or land use, or other factors.  Ozone data are used to determine to what extent sensitive vegetation or people in the national forests are at risk. This information will be used to make informed decisions related to land management planning, air pollution source permitting, and statewide air quality strategies.


Much of the water chemistry data at this website are provisional; that is, first order quality assurance has yet to be performed by the Forest Service. Additionally, the earliest of these data were collected with varing field protocols and so they deserve additional scrutiny. Recent data (in the last five years) were collected using consistent field protocols. We have good confidence that the laboratory physical and chemical analyses are generally of high quality. Although, we are active in evaluating and improving the quality of these data, we urge caution when drawing conclusions from them. Contact us for more details.

The ozone data have been subject to quality assurance and control by the Environmental Protection Agency (EPA) who operate the Clean Air Status and Trends Network (CASTNET), or air regulatory agencies that input the data into the EPA's Air Quality System (AQS). However, the data could be subject to correction in the future by the appropriate agency and probably will not be updated on this website.

Source of Data 

Today much of the water data available at this website are analyzed in the US Forest Service Air Resource Management Laboratory (ARML) in Fort Collins, CO. Should you want samples that were collected on or are representative of locations on the national forests to be analyzed by this laboratory, please contact us for details.

The hourly ozone data were obtained from the EPA CASTNET (, or Air Quality System (

Database Analyst

Questions about the water data or findings about quality or content should be directed to:
Barb Gauthier - Water Data Analyst
Office: (970) 295-6012
Cell: (970) 213-9103
Fax: (970) 295-5988

Questions about the ozone data should be directed to:
Bill Jackson
Office: (828) 257-4815

Additional Contacts

Ann Mebane
National Air Program
Office: (307) 578-8241

Last modified: Monday, 16-Dec-2013 14:19:04 CST
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