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USGS - science for a changing world


Acid Rain, Atmospheric Deposition and Precipitation Chemistry

picture of twirling vines in rain forest picture of water on rust dripping down picture of bluish abstract reflection in water picture of rain dripping in shallow water with granite bottom


Soil acidification from acid rain that is harmful to plant and aquatic life has now begun to reverse in forests of the northeastern United States and eastern Canada

Reduced acid rain levels resulting from American and Canadian air-pollution control measures have begun to reverse soil acidification across this broad region," said Gregory Lawrence, a USGS soil and water chemist and lead study author. "The start of widespread soil recovery is a key step to remedy the long legacy of acid rain impacts on terrestrial and aquatic ecosystems," according to Lawrence. The study is available at:

Estimates of Inorganic Nitrogen Wet Deposition from Precipitation for the Conterminous United States, 1955-84

The U.S. Geological Survey's National Water-Quality Assessment program requires nutrient input information for analysis of national and regional assessment of water quality. Historical data are needed to lengthen the data record for assessment of trends in water quality. This report provides estimates of inorganic nitrogen deposition from precipitation for the conterminous United States for 1955-56, 1961-65, and 1981-84. The estimates were derived from ammonium, nitrate, and inorganic nitrogen concentrations in atmospheric wet deposition and precipitation-depth data. A copy of this report, tabular datasets, and raster datasets of nitrogen from wet deposition are now available at:

USGS Measures Fallout from Fukushima in U.S. NADP Precipitation Samples

USGS and the National Atmospheric Deposition Program (NADP) networks measured fission-product isotopes in the U.S. from the Fukushima Dai-ichi nuclear power facility atmospheric release incidents, which occurred March 12 and 14, 2011 near Sendai, Japan.  This project added to the body of knowledge about radioactive fallout from the March 12-14, 2011 incident and exhibited the capabilities of the USGS and NADP to respond to an unexpected atmospheric release. Details and publications on the results are now available at

USGS Scientists Lead and Contribute to Major Report To Congress on Acid Rain

USGS scientists Douglas Burns and Jill Baron led and contributed to a major report to Congress released January 19, 2012 on the effects of acid rain on sensitive ecosystems and progress towards minimizing those impacts in the United States. A summary and copy of the full report is now available at:


The U.S. Geological Survey (USGS) is the lead federal agency for the monitoring of wet atmospheric deposition (chemical constituents deposited from the atmosphere via rain, sleet, and snow) in the United States. The USGS atmospheric deposition program provides: 1) participation and leadership in the National Atmospheric Deposition Program (NADP) and 2) scientific research and assessment to evaluate trends and the effects of atmospheric deposition on aquatic and terrestrial ecosystems.

      image of fact sheet Atmospheric Deposition Program, U.S. Geological Survey Fact Sheet, 2000, 112-00: 27:36

National Atmospheric Deposition Program (NADP)
The NADP monitors wet atmospheric deposition at approximately 300 locations  throughout the United States. The USGS supports 76 of the roughly 250 NADP National Trends Network sites which measure acidity, nutrients and other major ions in precipitation. The USGS also supports 1 of the approximately 100 sites in the NADP Mercury Deposition Network which measure total and methyl mercury in precipitation. A fundamental NADP program objective is to provide scientists, resource managers and policy-makers world-wide with a long-term, high-quality database of atmospheric deposition to support research and decision-making in the areas of air quality, water quality, agricultural effects, forest productivity, materials effects, ecosystem studies, watershed studies, and human health.

NTN map
NADP - National Trends Network (Feb.19, 2015)
NADP - Mercury Deposition Network (Feb. 23, 2015)

red dots = USGS supported sites
black dots = Other sites

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Page Last Modified: 02/09/2012