National Lakes Assessment Project (NLAP)
Minnesota’s participation in the U.S. Environmental Protection Agency’s (USEPA) 2012 NLA involved a collaborative approach that included USEPA, U.S. Forest Service (USFS), MN Department of Natural Resources (MDNR), MN Department of Health (MDH), MN Department of Agriculture (MDA) and the Red Lake and White Earth Native American Bands. A total of 1,000 lakes was included in the national survey. Minnesota drew 42 lakes as a part of the initial draw for this statistically based national survey effort and added 8 lakes to allow for state-based assessment. All 50 lakes received the national level of assessment and contributed to both the state-based and national assessments. In addition, 100 lakes were added from USEPA’s randomized list of lakes to allow for ecoregion-based assessments (50 per major ecoregion) in Minnesota.
This collaboration and the various survey add-ons were the basis for several “value-added” topics.
- Emerging contaminant analysis in 50 lakes (MPCA)
- Pesticide analysis in 50 lakes and triazine analysis in all 150 lakes (MDA)
- Zooplankton analysis in all 150 lakes (MDNR)
- Blue-green algal toxin (microcystin) in all 150 lakes (lab analysis by MDH, reporting by MPCA)
- Water chemistry and profiles in all 150 lakes, including comparisons among 2007 and 2012 results (MPCA)
NLA 2012 statewide reports
A series of reports is being drafted based on the 2012 NLA. These reports or their links will be posted here as they are completed. The following reports are now available:
- Overview of Minnesota’s 2012 Survey
MPCA’s plan to sample 150 lakes as a part of the 2012 NLA was ambitious. Weather conditions in summer 2012 were challenging and included record rainfall events in June and transitioned to severe drought over much of the state by mid-summer. This resulted in numerous lakes being dry or too shallow to sample over much of the state.
- Pharmaceuticals and Endocrine Active Chemicals in Minnesota Lakes
Many previous studies have established that a variety of pharmaceuticals, personal care products (PPCPs), and other chemicals are commonly detected at low concentration in rivers and lakes. However, this was the first study to analyze this suite of chemicals in randomly-selected lakes. Forty-seven of the 50 lakes sampled had at least one of the chemicals that were tested for. The insect repellent DEET was found in 76 percent of the lakes sampled, making this chemical the most frequently discovered.
- Pesticides in Minnesota Lakes  (Minn. Dept of Agriculture)
Minnesota was the only state in the 2012 NLA to include comprehensive testing for pesticides as a part of the study. Fifty-two lakes were analyzed using the MDA laboratory’s gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) advanced methods for 132 different pesticide compounds. Nineteen different pesticide compounds were detected, with atrazine being discovered most frequently in 67 percent of samples. A comparison of 2012 and 2007 pesticide data notes a decrease in the detection frequency of atrazine and related compounds.
NLA lake-specific reports
These brief reports summarize data for one or more lakes that were included in the study. These reports are prepared as a service to study collaborators, including property owners that have granted access to the lakes. This page will be populated as reports are created.
- Lakes on the White Earth Reservation
- Lakes on the Red Lake Reservation
- Lakes in Tamarac Wildlife Refuge
- Lakes in Northeastern Minnesota
For more details on the national study: National Lakes Assessment (U.S. EPA)
For additional information about this project, please contact Steve Heiskary at 651-757-2419, or toll-free at 800-657-3864.
NLAP archived statewide reports
This report series will examine statewide patterns in various chemical, physical and biological parameters based on data collected during the NLAP survey.
- Microcystin Concentrations in Minnesota Lakes
- Aquatic Macrophytes in Minnesota Lakes
- Water Mercury Concentrations in Minnesota Lakes
- Fish-based Index of Biotic Integrity (IBI) for Minnesota Lakes
- Pesticides in Minnesota Lakes  (Minn. Dept. of Agriculture)
- An overview of water chemistry in Minnesota lakes
NLAP archived survey reports for select Minnesota lakes
These lake information sheets contain a brief description of each lake sampled for the Environmental Protection Agency National Lake Assessment Program: general information about lake area and depth, watershed area and land use composition, lake dissolved oxygen and temperature profiles, and water quality data from the survey. The typical range of water quality values for each ecoregion is provided as a basis for comparison. Data tables will be periodically updated as more data becomes available.
|Blue Earth||Eagle (North)|
|Crow Wing||Crow Wing|
|Itasca||Long (Main Bay)|
|Le Sueur||Upper Sakatah|
|Otter Tail||West Leaf|
|Otter Tail||Maine (Round)|