Sample Archive Disposal

The NADP Central Analytical Lab will begin disposal of NTN, AIRMoN and AMoN archived samples which have reached their active archive expiration holding period (NTN = 6 year anniversary, AIRMoN and AMoN = 3 year anniversary). On September 19th, 2019 these samples will no longer be available for request. The following samples are available prior to disposal:

  • NTN Archive Samples: 10 to 60 mL filtered precipitation (stored at 4°C)
  • AIRMoN Archive Samples: 10 to 200 mL unfiltered precipitation (stored at 4°C)
  • AMoN Extracts - ~5 mL of passive ammonia sampler extract (stored frozen)

Please contact the NADP Program Coordinator, Mike Olson at 608-263-9162 or at for sample archive requests.

Nr Deposition Science Needs White Paper

NADP's Total Deposition Science Committee (TDep) has released a white paper, Science needs for continued development of total nitrogen deposition budgets in the United States".

CAL Readiness Verification Report

The CAL Readiness Verification Report has been released

Happy 40th Anniversary to NADP!

The very first NADP samples on July 5, 1978 were from: NC25, Coweeta in Macon, NC; WV18, Parsens in Tucker, WV; MN16, Marcell Experimental Forest in Itasca, MN.

NADP has moved

The NADP Program Office (PO) and Central Analytical Lab (CAL) moved in 2018 from the University of Illinois (U of I) to their new home at the University of Wisconsin's State Laboratory of Hygiene (WSLH) in Madison, WI. The Mercury Analytical Lab (HAL) moved from Frontier-Eurofins in Seattle, WA to the WSLH in 2019.

NADP Impact Statement

The NADP is the State Agriculture Experiment Station (SAES) National Research Support Program 3 (NRSP-3). SAES recently published a 2-page Impact Statement that highlights NADP’s accomplishments for the period 2009-2014.

Total Deposition Maps now Available

NADP has just released a new series of maps, which are estimates of dry plus wet deposition for sulfur and nitrogen. The maps are based on a new hybrid method of determining total deposition, which was developed within the NADP Total Deposition Science Committee (TDEP) . Check out the website for more details and to see the maps!

Litterfall Mercury Monitoring Initiative

The National Atmospheric Deposition Program (NADP) has a new litterfall mercury monitoring initiative to complement the Mercury Deposition Network (MDN) monitoring for mercury in precipitation and the Atmospheric Mercury Network (AMNet) monitoring for mercury in air