Water Resources of Minnesota

News from the MNWSC

Report Published: Presence of Selected Chemicals of Emerging Concern in Water and Bottom Sediment from the St. Louis River, St. Louis Bay, and Superior Bay, Minnesota and Wisconsin, 2010

The lower St. Louis Bay between Duluth, Minnesota and Superior, Wisconsin receives substantial urban runoff, wastewater treatment plant effluent, and industrial effluent-leading to its designation as a "Great Lakes Area of Concern" by the International Joint Commission. Concerns exist about the potential effects of certain chemicals on aquatic biota because many of these chemicals have been shown to have detrimental effects on fish and other aquatic life. These chemicals are called Chemicals of Emerging Concern and may be toxic or pose some health risk to living organisms. These chemicals include pharmaceuticals, hormones, and other organic chemicals-some of which may cause endocrine disruption.
More Information | Full Report

Report Published: Relations between Retired Agricultural Land, Water Quality, and Aquatic-Community Health, Minnesota River Basin

The U.S. Geological Survey is pleased to announce the release of Relations between Retired Agricultural Land, Water Quality, and Aquatic-Community Health, Minnesota River Basin, published in the September 2012 issue of the Journal of Environmental Quality. The study demonstrates importance of agricultural land retirement on water quality and aquatic-community health in the Minnesota River Basin.
More Information | Full Article

Freshwater Society Lecture on 'Confounding Problem' of Nitrogen Pollution

Nitrogen. It makes up three-fourths of the air all around us. It cascades through our environment between land, water and the atmosphere. It is critical to agricultural production that feeds the world. And it is a byproduct of all the fossil fuels we consume.
In the United States, we put five times more nitrogen into the environment than is deposited or released naturally. That excess nitrogen causes a variety of environmental and health problems - pollution of ground and surface waters, smog, increased emissions of greenhouse gases.
On Oct. 4, 2012, the Freshwater Society and the University of Minnesota College of Biological Sciences will present an important lecture by Purdue University professor Otto Doering on the problem of excess nitrogen. It is an issue that the National Academy of Engineering has called one of the "grand challenges" facing this country in the 21st Century.
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Summer 2012 Newsletter Released

The Summer 2012 newsletter highlights some exciting projects, recaps the flooding in northern Minnesota, and introduces some upcoming conferences.

Areas of Elevated Contaminants in Groundwater Determined from Regional Assessment in the Midwest

At least one contaminant was found at levels of human-health concern in about one third of untreated groundwater samples collected from wells in the Cambrian-Ordovician aquifer system, according to a recent report by the U.S. Geological Survey. When radon concentrations greater than 300 picocuries per liter are included, 64 percent of wells sampled contain a contaminant concentration above a human-health benchmark.

The Cambrian-Ordovician aquifer system is ranked ninth in the nation for public supply water withdrawals from principal aquifers. The aquifer supplies water to many parts of the northern Midwest, including areas of Minnesota, Wisconsin, Illinois, Iowa, Missouri, and the Upper Peninsula of Michigan, as well as the major cities of Minneapolis, Rockford and Chicago.

Many of the public and private wells sampled contain natural or manmade contaminants, including; radium, radon, boron, strontium, manganese, barium, nitrate, pesticides, and volatile organic compounds. Radon and radium are naturally occurring radioactive elements and known carcinogens. The deeper parts of the aquifer system in Illinois, Iowa, and eastern Wisconsin are vulnerable to high concentrations of radium, boron, and strontium. The shallow areas of the aquifer system in Minnesota, Wisconsin, and the Upper Peninsula of Michigan are vulnerable to radon and manganese. The study was conducted as part of an ongoing systematic assessment of some of the Nation's most important aquifer systems by the USGS National Water-Quality Assessment (NAWQA) Program. Results are available online.
Full Press Release

New Report: Seasonal Patterns in Nutrients, Carbon, and Algal Responses in Wadeable Streams within Three Geographically Distinct Areas of the United States, 2007-08

The U.S. Geological Survey determined seasonal variability in nutrients, carbon, and algal biomass in 22 wadeable streams over a 1-year period during 2007 or 2008 within three geographically distinct areas in the United States. The three areas are the Upper Mississippi River Basin (UMIS) in Minnesota, the Ozark Plateaus (ORZK) in southern Missouri and northern Arkansas, and the Upper Snake River Basin (USNK) in southern Idaho. Seasonal patterns in some constituent concentrations and algal responses were distinct. Nitrate concentrations were greatest during the winter in all study areas potentially because of a reduction in denitrification rates and algal uptake during the winter, along with reduced surface runoff. Decreases in nitrate concentrations during the spring and summer at most stream sites coincided with increased streamflow during the snowmelt runoff or spring storms indicating dilution. The continued decrease in nitrate concentrations during summer potentially is because of a reduction in nitrate inputs (from decreased surface runoff) or increases in biological uptake. In contrast to nitrate concentrations, ammonia concentrations varied among study areas. Ammonia concentration trends were similar at UMIS and USNK sampling sites with winter peak concentrations and rapid decreases in ammonia concentrations by spring or early summer. In contrast, ammonia concentrations at OZRK sampling sites were more variable with peak concentrations later in the year. Ammonia may accumulate in stream water in the winter under ice and snow cover at the UMIS and USNK sites because of limited algal metabolism and increased mineralization of decaying organic matter under reducing conditions within stream bottom sediments. Phosphorus concentration patterns and the type of phosphorus present changes with changing hydrologic conditions and seasons and varied among study areas. Orthophosphate concentrations tended to be greater in the summer at UMIS sites, whereas total phosphorus concentrations at most UMIS and USNK sites peaked in the spring during runoff and then decreased through the remainder of the sampling period.
Full Report

New Report: Occurrence of triclosan, triclocarban, and its lesser chlorinated congeners in Minnesota freshwater sediments collected near wastewater treatment plants

The antimicrobial agents triclosan (TCS), triclocarban (TCC) and their associated transformation products are of increasing concern as environmental pollutants due to their potential adverse effects on humans and wildlife, including bioaccumulation and endocrine-disrupting activity. Analysis by tandem mass spectrometry of 24 paired freshwater bed sediment samples (top 10 cm) collected by the U.S. Geological Survey near 12 wastewater treatment plants (WWTPs) in Minnesota revealed TCS and TCC concentrations of up to 85 and 822 ng/g dry weight (dw), respectively. Concentrations of TCS and TCC in bed sediments collected downstream of WWTPs were significantly greater than upstream concentrations in 58% and 42% of the sites, respectively. Dichloro- and non-chlorinated carbanilides (DCC and NCC) were detected in sediments collected at all sites at concentrations of up to 160 and 1.1 ng/g dw, respectively. Overall, antimicrobial concentrations were significantly higher in lakes than in rivers and creeks, with relative abundances decreasing from TCC > TCS > DCC > NCC. This is the first statewide report on the occurrence of TCS, TCC and TCC transformation products in freshwater sediments. Moreover, the results suggest biological or chemical TCC dechlorination products to be ubiquitous in freshwater environments of Minnesota, but whether this transformation occurs in the WWTP or bed sediment remains to be determined.
Full Report

Flooding in Northcentral and Northeast Minnesota, Duluth Area - June 22-29, 2012

Severe flooding had occurred in northcentral and northeast Minnesota resulting from 8-10 inches of rain that fell June 19-20 along a stalled warm front near Duluth, Minnesota. Rain fell across the divide of three major basins, including Lake Superior, Mississippi, and the St Croix.

Updates to major streamgages recently peaked or peaking soon:

• Knife River at Two Harbors (37 years of record)
   Peaked at 16.64 ft or approximately 0.5 feet higher than peak of record. This peak has an annual exceedence probability (AEP) of <1% or >100 years.
• St. Louis River at Scanlon (104 years of record).
   Peaked June 21, 45,300 cfs; approximately 7,000 cfs greater than previous peak of record. This peak has an AEP of <1% or >100 years.
• Mississippi River near Aitkin (112 years of record)
   Peaked June 28-29, 15,000 cfs; approximately 5,000 cfs less than peak discharge of record and second highest peak discharge of record with an AEP between 4 and 2%.
• Mississippi River at Brainerd (24 years of record)
   Peaked June 28, 18,000 cfs; AEP between 5 and 2%.
• Kettle River near Sandstone (46 years of record)
   Peaked June 22, >23,300 cfs; approximately 6,000 cfs and 2.5 feet greater the peak of record. This peak has an AEP between 1 and 0.2%.

Flooding has caused estimated tens of millions of dollars of damages in Duluth, with more in surrounding communities. Many state and federal highways remain closed and likely will remain so for major repairs at some locations. Parts of cities and a State Park have been evacuated. There has been no known loss of human life.

Pictures:
USGS Minnesota | Star Tribune | Minnesota Public Radio

New Report: Endocrine Disrupting Chemicals in Minnesota Lakes-Water-Quality and Hydrological Data from 2008 and 2010

Understanding the sources, fate, and effects of endocrine disrupting chemicals in aquatic ecosystems is important for water-resource management. This study was conducted during 2008 and 2010 to establish a framework for assessing endocrine disrupting chemicals, and involved a statewide survey of their occurrence in 14 Minnesota lakes and a targeted study of different microhabitats on a single lake. The lakes ranged in size from about 0.1 to 100 square kilometers, varied in trophic status from oligotrophic to eutrophic, and spanned a range of land-uses from wetlands and forest to agricultural and urban use. Water and sediment samples were collected from the near-shore littoral environment and analyzed for endocrine disrupting chemicals, including trace elements, acidic organic compounds, neutral organic compounds, and steroidal hormones. In addition, polar organic compound integrative samplers were deployed for 21 days and analyzed for the same organic compounds. One lake was selected for a detailed microhabitat study of multiple near-shore environments. This report compiles the results from the field measurements and laboratory chemical analysis of water, sediment, and polar organic compound integrative sampler samples collected during 2008 and 2010. Most of the organic compounds measured were not detected in any of the water samples, although a few compounds were detected in several of the lakes.
Full Report

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