The goal of the NADP/NTN is to characterize the nation's chemical climate through precipitation collection and analysis. The program is a nationwide network of monitoring stations designed to measure atmospheric depositions and study its effects on the environment. It provides a long term record of precipitation chemistry across the United States.

When sulfur dioxides and nitrogen oxides are released into the atmosphere, they may react with oxidants, oxygen, and water forming compounds which fall to earth in the form of rain, fog, or snow (acid rain).

The human health concerns associated with acid rain include a variety of respiratory maladies such as damage to lung tissue, cancer, and premature death. In addition to health matters., acidification also endangers aquatic ecosystems, crop yields, buildings, historical monuments, and high elevation forests.

The Glacier National Park monitoring station (MT05) has been in operation continuously since 1980. Station operators collect weekly samples, which are sent to the Central Analytical Laboratory (CAL) at the Illinois State Water Survey for analysis. The CAL measures concentrations of calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), ammonium (NH4+), sulfate (SO42-), nitrate (NO3-), and chloride (Cl-). The hydrogen ion concentration (usually measured as pH) is also measured.

Belfort Rain Gauge

Aerochem collector