Send a comment on this item to LII: Send a comment on this item to LII staff, who on weekdays will usually reply within 24 hours. National Atmospheric Deposition Program (NADP) The purpose of this national network is "to collect data on the chemistry of precipitation for monitoring of ... long-term trends." Weekly samples are analyzed to learn acid rain (also known as "atmospheric deposition") content. The site features links to data and reports. The NADP is located at the Illinois State Water Survey, and is a cooperative program of federal, state, and non-governmental groups.  http://nadp.sws.uiuc.edu Asterisk * indicates required field. Your Name Your Email Address * We will not sell or provide your email address to anyone else. Comment * Enter the verification code as it is shown in the box below. This helps prevent automated submissions. *