Adirondack Long-Term Lakes Monitoring (ALTM)

Click Here for an interactive network map with links to site water quality data

The Adirondack Long-Term Lakes Monitoring Lakes (ALTM) project began in 1982 with the objective of tracking changes in the water chemistry of selected Adirondack lakes that are representative of lake types present throughout the Adirondacks. The network began by measuring the water chemistry at 17 lakes in the Adirondack Mountains. In 1992, the project was expanded to include 52 lakes sampled monthly with a goal of assessing the effectiveness of Title IV of the Clean Air Act Amendments of 1990 to reduce acidic deposition through the regulation of sulfur and nitrogen emissions from fossil fuel burning power plants. From 1992 to 2016 the Adirondack Lake Survey Corporation (ALSC) laboratory analyzed samples for the ALTM. Since 2018, routine monitoring of 58 lake sites (51 lakes and 7 outlets) has followed a seasonal or annual collection frequency depending on the lake. Seasonal sampling is conducted in February, April, May, July, September and November, and annual sampling is conducted in July or August.

In 2016 the New York Water Science Center Soil and Low Ionic Strength Laboratory took over ALTM sample analyses. Currently, ALTM sampling and analyses are funded by the New York State Energy Research and Development Authority (NYSERDA) and the US Environmental Protection Agency (EPA). The New York State Department of Environmental Conservation (NYSDEC) has supported the program throughout its history by providing cost-sharing for transportation for lake sampling, facilities and laboratory equipment for ALSC and guidance for the ALTM program.

The second edition of the Compendium of Adirondack Long-Term Monitoring Lakes was published by NYSERDA in 2019. The report is a compendium of site descriptions, lake chemistry and recent research results for the 52 ALTM Lakes. The site descriptions include lake watershed maps, lake bathymetry, drainage classification and acid sensitivity as well as detailed lake characteristics such as elevation, depth, volume, surface area, watershed area, hydraulic retention time and land use classification. The compendium is also available for download below in the attached file section.


Site Locations:

The sampling locations of all ALTM lakes are included in a map to the upper right of this page. Clicking on the map will bring up a map viewer or the data can be downloaded in Google Earth file format (KML). Spatial Services are also enabled for the spatial data under the heading “Spatial Services”; click the button to the right of the spatial service desired (ArcGIS Mapping Service, WMS Service, or WFS Service) to copy the link and then paste that link into your browser. 

Data Availability: