OFR14-02, Geologic controls on groundwater and surface water flow in southeastern Minnesota and its impact on nitrate concentrations in streams

Not fully edited to MGS publication standards.This report summarizes the results of a Minnesota Geological Survey (MGS) investigation conducted for the Minnesota Pollution Control Agency (MPCA) designed to support watershed planning efforts in southeast Minnesota. Specifically it provides better understanding of the geologic controls on nitrate transport in the region, including nitrate in groundwater that is the source of baseflow to streams. Nitrate contamination of surface water and groundwater is a long- standing issue in southeastern Minnesota. We focused much of our investigation on an evaluation of nitrate (NO3 ion) transport in the Root River watershed because of the relatively advanced understanding of the karstic conditions in that area. However, the overall scope of the project includes the entire bedrock-dominated landscape of southeast Minnesota. Our results therefore support a broader MPCA watershed planning effort that directly pertains to the Root River, as well as to other watersheds within the Lower Mississippi River Basin in Minnesota.This report is a contract deliverable summarizing work conducted by the Minnesota Geological Survey for the Minnesota Pollution Control Agency, Contract number B50858 (PRJ number PRJ07522), entitled “Geologic Controls on Nitrate in Southeast Minnesota Streams

C-45, Geologic Atlas of Hennepin County, Minnesota

Plate 1, Data Base, Plate 2, Bedrock Geology, Plate 3, Surficial Geology, Plate 4 Quaternary Stratigraphy, Plate 5 Sand Distribution Model, Plate 6 Bedrock Topography and Depth-to-Bedrock, Scale 1:100,000, 1:300,000 (sand model imagery). April 2, 2019 -- Uploaded new rasters for the bedrock surfaces and an update of the County Geologic Atlas Users Guide for 2019 (Updated Files) These replace the files in the Supplemental Digital and GIS data zip file.A County Geologic Atlas project is a study of a county's geology, and its mineral and ground-water resources. The information collected during the project is used to develop maps, data-base files, and reports. This same information is also produced as digital files for use with computers. The map information is formatted as geographic information system (GIS) files with associated data bases. The maps and reports are also reproduced as portable document files (PDFs) that can be opened on virtually any computer using the free Acrobat Reader from Adobe.com. Note: Bedrock surfaces rasters and the Atlas Users guide were updated (updated_files.zip) 04/01/19.Hennepin County Board of Commissioners, Minnesota Environmental and Natural Resources Trust Fund as recommended by the Legislative - Citizen Commission on Minnesota Resources, Minnesota Legacy Amendment's Clean Water Fund

C-47, Geologic Atlas of Rock County, Minnesota

The printed Rock County Geologic Atlas is comprised of 6 Plates. Plate1, Database Map; Plate2, Bedrock Geology; Plate3, Surficial Geology; Plate4, Quaternary Stratigraphy; Plate5, Sand-Distribution Model; and Plate6, Bedrock Topography and Depth to Bedrock. Digital files are included in the Supplemental digital and GIS data available for download or via DVD from the Minnesota Geological Survey.A County Geologic Atlas project is a study of a county's geology, and its mineral and ground-water resources. The information collected during the project is used to develop maps, data-base files, and reports. This same information is also produced as digital files for use with computers. The map information is formatted as geographic information system (GIS) files with associated data bases. The maps and reports are also reproduced as portable document files (PDFs) that can be opened on virtually any computer using the free Acrobat Reader from Adobe.com.Prepared and Published with the Support of THE ROCK COUNTY BOARD OF COMMISSIONERS, THE MINNESOTA DEPARTMENT OF NATURAL RESOURCES, THE MINNESOTA ENVIRONMENTAL AND NATURAL RESOURCES TRUST FUND AS RECOMMENDED BY THE LEGISLATIVE-CITIZEN COMMISSION ON MINNESOTA RESOURCES

C-48, Geologic Atlas of Nobles County, Minnesota

The printed Nobles County Geologic Atlas is comprised of 6 Plates. Plate1, Database Map; Plate2, Bedrock Geology; Plate3, Surficial Geology; Plate4, Quaternary Stratigraphy; Plate5, Supplemental Quaternary Stratigraphy and Sand-Distribution Model; and Plate6, Bedrock Topography and Depth to Bedrock. Digital files are included in the Supplemental digital and GIS data available for download or via DVD from the Minnesota Geological Survey.A County Geologic Atlas project is a study of a county's geology, and its mineral and ground-water resources. The information collected during the project is used to develop maps, data-base files, and reports. This same information is also produced as digital files for use with computers. The map information is formatted as geographic information system (GIS) files with associated data bases. The maps and reports are also reproduced as portable document files (PDFs) that can be opened on virtually any computer using the free Acrobat Reader from Adobe.com.Prepared and Published with the Support of THE NOBLES COUNTY BOARD OF COMMISSIONERS, THE MINNESOTA DEPARTMENT OF NATURAL RESOURCES, AND THE MINNESOTA ENVIRONMENT AND NATURAL RESOURCES TRUST FUND AS RECOMMENDED BY THE LEGISLATIVE-CITIZEN COMMISSION ON MINNESOTA RESOURCE

OFR14-04, Hydrogeologic Properties of the St. Lawrence Aquitard, Southeastern Minnesota

Results are synthesized into a conceptual model of flow through the lower Jordan Sandstone, St Lawrence Formation, and upper Tunnel City Group in variable geologic conditions. This provides a better understanding of the “aquitard integrity” of these and other bedrock units inferred to protect deeper groundwater in southeastern Minnesota.To better understand the properties of bedrock aquitards, we initiated a project that utilizes widely ranging methods to gain insights into the properties of the St Lawrence Formation and adjacent strata of the upper Tunnel City Group (Mazomanie and Lone Rock Formations) and lower Jordan Sandstone. The St Lawrence Formation has been traditionally regarded as an aquitard in the Paleozoic bedrock hydrogeologic system.Our investigation addresses hydraulic properties at site-specific as well as sub-regional (square miles) scales. Specific activities included drilling, testing and instrumentation of a borehole in the eastern Twin Cities Metro area (TCMA), the Afton multilevel system (MLS) hole, that has provided us with detailed multi-level measurements of hydraulic characteristics above, below and within the St. Lawrence Formation. We also analyzed the distribution of fractures in bedrock outcrops, in an effort to understand the controls these fractures might have on borehole hydraulic conditions. Borehole and outcrop scale data are augmented with ground-water tracer experiments that provide horizontal and vertical travel times at the sub-regional scale. Compilation of existing published and unpublished hydraulic and water chemistry data provide additional insights into the properties of the St Lawrence Formation and adjacent units across a wider extent of southeastern Minnesota.Funded through the Environment and Natural Resource Trust Fund as recommended by the Legislative and Citizen’s Commission on Minnesota Resources (LCCMR)