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Research about Minnesota

Source-linked reports with geographic coverage including Minnesota.

At least 667 records · Page 37Linked to original sources
USGS1986

Hydrogeologic and water-quality characteristics of crystalline-rock aquifers of Archean and Proterozoic age, Minnesota

Five aquifers in crystalline rocks of Archean and Proterozoic age in Minnesota include in descending order the North Shore Volcanic, Sioux Quartzite, Proterozoic metasedimentary, Biwabik Iron formation and undifferentiated Precambrian aquifers. The North Shore Volcanic aquifer generally yields < 15 gal/min to wells from interflow sediments and fractures in the basaltic lava flows along the northern shore of Lake Superior and along the upper St. Croix River. Dissolved solids concentrations range from 91 to 74,300 mg/L, and the water is of several chemical types. The Sioux Quartzite aquifer yields from 1 to 450 gal/min to wells open to joints and fractures and loose sand zones in the predominantly pink orthoquartzite in southwestern Minnesota. Dissolved solids concentrations range from 237 mg/L in water from wells in outcrop areas to 2,300 mg/L from wells where the Sioux Quartzite aquifer underlies Cretaceous rocks or thick Des Moines drift. The water generally is a calcium sulfate type. The Proterozoic metasedimentary aquifer generally yields < 20 gal/min to wells in weathered regolith and fractures in thin-bedded gray to black argillite in north-central Minnesota. Dissolved solids concentrations generally range from 126 to 340 mg/L, and the water is a calcium magnesium bicarbonate type. The Biwabik Iron formation aquifer yields 1,000 gal/min to wells in leached zones in the ferruginous chert and interbedded hematite and magnitite iron ore in north-central Minnesota. Dissolved solids range from 157 to 388 mg/L in water that is a calcium magnesium bicarbonate type. The undifferentiated Precambrian aquifer generally yields < 25 gal/min to wells from fractures and the weathered regolith developed on a variety of crystalline-rock types. Wells have been developed in parts of the aquifer throughout the State except in the southeast where it is too deeply buried. Dissolved solids concentrations average < 400 mg/L in central and northeastern Minnesota, but average about 700 mg/L in the northwest and 900 mg/L in the south west. The water is a calcium magnesium bicarbonate type in central and northeastern Minnesota and a variety of mixed water types in northwestern and Southwestern Minnesota.

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USGS1986

Hydrogeology of confined-drift aquifers near the Pomme de Terre and Chippewa rivers, western Minnesota

Confined-drift aquifers in a 1,380-square-mile area of western Minnesota range in thickness from less than 10 feet to 114 feet. Transmissivities range from less than 1,000 square feet per day to over 16,000 square feet per day and theoretical well yields range from less than 100 gallons per minute to more than 1,800 gallons per minute. Regional ground water flow in the confined-drift aquifers is toward the Minnesota River and locally toward smaller streams, lakes, wetlands, and wells. Water levels near high-capacity pumping wells generally fluctuate 5 to 10 feet annually, compared to annual fluctuations of 2 to 3 feet in the surficial aquifers. Water from confined-drift aquifers generally is suitable for most uses. The water is hard to very hard and contains locally elevated concentrations of some chemical constituents. Dissolved-solids concentrations ranged from about 400 to 1,800 milligrams per liter. A ground-water-flow model indicated that increased pumping from two of the confined aquifers simulated, the Appleton and Benson-middle aquifers, would not adversely affect water levels. The addition of 30 hypothetical wells in the Benson-middle aquifer, pumping a total of approximately 792 million gallons per year, resulted in regional water-level declines of as much as 1.4 and 2.7 feet in the surficial and Benson-middle aquifers, respectively. The addition of 28 hypothetical wells in the Appleton aquifer, pumping a total of approximately 756 million gallons per year, lowered water levels as much as 5 feet in the surficial and Appleton aquifers. Simulations of reduced recharge and increased pumping, which could represent a 3-year drought, probably would lower water levels 2 to 6 feet regionally in the surficial and confined aquifers and as much as 11 feet near aquifer boundaries. Ground-water discharge to the Pomme de Terre and Chippewa Rivers in the southern part of the study area probably would be reduced by approximately 15.2 and 7.4 cubic feet per second, respectively, as a result of the simulated drought. Mean discharge of the Pomme de Terre and Chippewa Rivers is 104 and 267 cubic feet per second, respectively.

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USGS1985

Partitioning studies of coal-tar constituents in a two-phase contaminated ground-water system

Organic compounds derived from coal-tar wastes in a contaminated aquifer in St. Louis Park, Minnesota, were identified, and their partition coefficients between the tar phase and aqueous phase were determined and compared with the corresponding n-octanol/water partition coefficients. Coal tar contains numerous polycyclic aromatic compounds, many of which are suspected carcinogens or mutagens. Groundwater contamination by these toxic compounds may pose an environmental health hazard in nearby public water-supply wells. Fluid samples from this aquifer developed two phases upon settling: an upper aqueous phase, and a lower oily-tar phase. After separating the phases, polycyclic aromatic compounds in each phase were isolated using complexation with N-methyl-2-pyrrolidone and identified by fused-silica capillary gas chromatography/mass spectrometry. Thirty-one of the polycyclic aromatic compounds were chosen for further study from four different classes: 12 polycyclic aromatic hydrocarbons, 10 nitrogen heterocycles, 5 sulfur heterocycles, and 4 oxygen heterocycles. Within each compound class, the tar/water partition coefficients of these compounds were reasonably comparable with the respective n-octanol/water partition coefficient.

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USGS1985

Hydrocarbon source rock evaluation of Middle Proterozoic Solor Church Formation, North American Mid-Continent Rift System, Rice County, Minnesota

Hydrocarbon source rock evaluation of the Middle Proterozoic Solor Church Formation (Keweenawan Supergroup) as sampled in the Lonsdale 65-1 well, Rice County, Minnesota, shows that: (1) the rocks are organic matter lean (24 of 25 samples have less than 0.8% organic carbon); (2) the organic matter is thermally post-mature, probably near the transition between the wet gas phase of catagenesis and metagenesis (dry gas zone); and (3) the rocks have minimal potential for producing additional hydrocarbons (genetic potential < 0.30 mg HC/g rock). Although no direct evidence exists from which to determine maximum burial depths, the observed thermal maturity of the organic matter requires significantly greater burial depths, a higher geothermal gradient, or both. It is likely, t least on the Saint Croix horst, that thermal maturation of the organic matter in the Solor Church took place relatively early, and that any hydrocarbons generated during this early phase were probably lost prior to deposition of the overlying Middle Proterozoic Fond du Lac Formation (Keweenawan Supergroup).

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USGS1985

Trends in municipal-well installations and aquifer utilization in southeastern Minnesota, 1880-1980

Water distributed by municipal systems has been the largest off-stream use of water in southeastern Minnesota for the past 100 years. Water pumped by these systems in 1980 totaled 102.3 billion gallons, with 60.1 billion gallons supplied by ground water. Ground water supplies 294 of the 309 municipal systems in the area. The development of ground-water supplies for municipal use in southeastern Minnesota began around the 1880's as an alternative to supplies from lakes and rivers. After about 4,500 Minnesotans died from typhoid from 1891 to 1900, deep wells became widely used in order to avoid contaminated surface water. An inventory of 1,244 wells drilled for municipal systems from 1880 to 1980 has been completed. Of the five bedrock aquifers in the study area, the Prairie du Chien-Jordan is the most extensively used for water supply; 537 municipal wells tap it. About half of these wells were drilled in the Twin Cities Metropolitan Area since 1945 to accommodate suburban growth. The undifferentiated drift aquifer ranks second in use with 294 municipal wells tapping it. Most of these wells are completed in aquifers buried in thick drift deposits in the western part of the study area. Aquifer preference was analyzed to determine whether municipal wells were completed in the shallowest bedrock aquifer present in an area, in a deeper bedrock aquifer, or in a drift aquifer above the bedrock. Until 1950, there was a strong preference to complete municipal wells in the Upper Carbonate aquifer. Because of poor water quality in parts of the aquifer, most municipal wells drilled in the area since 1950 are cased through the Upper Carbonate and completed in deeper aquifers. The St. Peter aquifer is little used for municipal wells because wells completed in it often pump sand. About 96 percent of the municipal wells drilled in the St. Peter aquifer subcrop area since 1950 were cased through the St. Peter and completed in deeper aquifers. About 64 percent of the municipal wells drilled in the Mount Simon-Hinckley aquifer subcrop area are completed in drift aquifers. The Prairie du Chien-Jordan and Ironton-Galesville aquifers are preferred for municipal wells in their respective areas of occurrence. Water appropriation in Minnesota is regulated through a permit system based on five water-use priorities. Domestic water supply, excluding industrial and commercial uses of a municipal water supply, is the highest priority (Minnesota Statutes, Chapter 105.41). Under the regulations, uses of a lower priority are not permitted to adversely affect uses of a higher priority. Identification of the aquifer(s) used for municipal supplies is also necessary to safeguard these supplies from adverse effects of competing water users and contamination, and to evaluate the consequences of each.

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USGS1985

Rainfall-runoff relationships and water-quality assessment of Coon Creek watershed, Anoka County, Minnesota

Rainfall-runoff relationships and results of water-quality analyses were studied to develop an understanding of flooding problems and to assess present and potential water-quality problems in the 96.9-square-mile Coon Creek watershed, Anoka County, Minnesota. Rainfall, runoff, and water-quality data were collected from March 1979 to November 1980 at five continuously recording streamflow sites, seven crest-stage sites, and three continuously recording rainfall sites. During the study, eight storms occurred with sufficient rainfall to produce measurable runoff at most of the gages in the basin. The resulting hydrographs show, as expected, higher unit peaks, shorter times to peak, and shorter durations of high flows in streams draining urban areas than in streams draining rural areas. Constrictive culverts and bridges at roadways resulted in attenuation of hydrograph peaks in urban areas. Runoff amounts were nearly the same in all the subareas for storms with uniformly distributed rainfall. The greatest recorded rainfall during this study was 3.95 inches on August 7, 1980. The basin-weighted rainfall for that date was 3.56 inches, which resulted in the greatest observed peak flow for Coon Creek at Coon Rapids Boulevard of 185 cubic feet per second. The eight storms produced eight hydrographs suitable for model simulation of Sand Creek, seven hydrographs for simulation of Coon Creek, and four hydrographs for simulation'of County Ditch 58. The U.S. Army Corps of Engineers HEC-1, Flood Hydrograph Package computer model was used with the parameteroptimization routine to develop parameter values to closely match observed hydrographs. A multiple-linear-regression technique was used to develop linear equations for relating HEC-1 parameters to variations in rainfall and antecedent moisture. Tftiis procedure resulted in generalized models of the three principal subareas that reasonably simulated 10 of the 19 observed hydrographs. Water-quality characteristics were determined based on 14 water samples from 4 sites and 1 bottom-mate rial sample from each site. Results of the analyses indicated that streams draining urban areas carry the highest concentrations of most constituents sampled. Sand Creek at Xeon Boulevard, which drains the most urbanized area, had the highest mean concentration of metals, chloride, dissolved solids, and suspended sediment. Concentrations of total phosphorus ranged from 0.04 to 0.43 milligram per liter at the rural sites on County Ditch 58 at Andover Boulevard and Coon Creek at Raddison Road. Average phosphorus concentrations at the rural sites are comparable to concentrations at the urban sites.

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USGS1985

Fishery survey and related limnological conditions of Williams Lake, Hubbard County, Minnesota

Bluegill ( Lepomis macrochirus ), pumpkinseed sunfish ( Lepomis gibbosus ), largemouth bass ( Micropterus salmoides ), yellow perch ( Perca flavescens ) rock bass ( Amploplites rupestris ), black crappie ( Pomozis nigromaculatus ), and northern pike ( Esox lucius ) were found in Williams Lake, Hubbard County, Minnesota, during a fishery survey of the lake in late August 1982. The most abundant fish were the bluegills. These fish live in the large littoral zone of the lake; this zone underlies 55% of the surface area of the lake. The most ubiquitous benthic invertebrate in the littoral zone ( amphipods ) and the most abundant benthic invertebrate ( chironomid larvae ) were major food sources for the bluegill. Other organisms found in the stomach contents of fish collected in this survey were zooplankton, gastropods, Diptera larvae, odonates, terrestrial insects, and other fish. Daphnia were the only zooplankters of a diverse plankton community that were found in stomach contents. The abundance of fish other than bluegill was typical for a system in which northern pike is the major predator.

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USGS1985

Ground-water flow in the Prairie du Chien-Jordan aquifer related to contamination by coal-tar derivatives, St. Louis Park, Minnesota

A three-dimensional, ground-water-flow model of the Prairie du Chien-Jordan aquifer and associated hydrogeologic units was developed to evaluate the movement of coal-tar derivatives from a coal-tar distillation and wood-preserving plant in St. Louis Park, Minnesota. A finite-difference grid was superimposed on the modeled area, which includes most of eastern Hennepin County. The individual cells are 400-foot squares in the center of the grid (St. Louis Park area); the cells increase in dimension toward the outside limits of the grid. Five geologic units are represented by four layers in the model. These units include the Jordan Sandstone, the Prairie du Chien Group (dolomite and sandy dolomite), the basal confining unit of the St. Peter Sandstone (silty and sandy shale), the St. Peter Sandstone, and glacial deposits in bedrock valleys. The model was calibrated for steady-state conditions for a period before significant ground-water development (1885-1930) and for a period of significant pumping stress (winter conditions, 1970 fs). A transient calibration was accomplished by simulation of a period during which seasonal changes in potentiometric head in the Prairie du Chien-Jordan aquifer were significant (1977-80). Sensitivity testing indicated that leakage to the upper model layer and the vertical hydraulic conductivity of the basal confining unit of the St. Peter Sandstone were the model hydrologic properties which, when changed, resulted in the greatest changes in model-calculated water levels. The calibrated model generally calculates water levels that are within 10 feet of measured values. Model simulations indicate that the potentiometric surface of the Prairie du Chien-Jordan aquifer would be raised by as much as 3 feet in the area of the plant site by water introduced into the aquifer through wells open to more than one aquifer system. The cones of impression created at these wells could have a significant impact on the transport of contaminants in the Prairie du Chien-Jordan. The presence of coal-tar derivatives in the aquifer has been difficult to explain in wells located upgradient from the plant site to the north, west, and southwest. Simulations suggest that, during periods of heavy withdrawal from certain of these wells (SLP10, SLP15, and SLP5), local hydraulic gradients may have been altered, resulting in the potential for the movement of contaminants from the area of the plant site to the wells. Cones of impression at multiaquifer wells near the plant site contributed to the alteration of local gradients. Simulation of a proposed gradient-control plan, in which lateral homogeneity and isotropy of individual hydro geologic units was assumed, indicates that the actions would be effective in limiting expansion of the contaminated volume in the Prairie du Chien-Jordan aquifer. The plan includes the control of withdrawal from five wells. The simulations also show, however, that modelcalculated potentiometric surfaces are sensitive to changes in withdrawal rates at wells not intended to be under the control of the plan. Management of discharge from these wells also will be important to overall effectiveness of the remedial-action plan.

Minnesota↗
USGS1985

Seismic-refraction study of suspected drift-filled bedrock valleys in Ramsey County, Minnesota

Seismic-refraction surveys were made across suspected buried, drift-filled bedrock valleys believed to underlie two sites of known ground-water contamination the Twin Cities Army Ammunition Plant (TCAAP) near New Brighton and the former Koppers Coke Plant in St. Paul, Ramsey County, Minnesota. Refraction data were collected along two lines at each site; each line traversed the axis of a suspected valley. Drift-filled bedrock valleys were thought to incise the Prairie du Chien-Jordan aquifer to an altitude between 500 and 560 feet above sea level at the TCAAP site. The interpretation of one seismic profile indicates that a valley probably does not exist under the area surveyed; the modeled depth profile shows the bedrock surface ranging between altitudes of about 700 to 780 feet. Interpretation of a second seismic profile just south of the TCAAP indicates that a shallow valley may exist under the northern half of the line; the modeled depth profile shows that the bedrock surface declines from an altitude of about 780 feet to about 690 feet over a horizontal distance of 400 feet. A drift-filled bedrock valley was thought to incise the St. Peter aquifer to an altitude between 770 and 800 feet above sea level at the Koppers site. The interpretation of a seismic profile just east of the Koppers site is not conclusive, but suggests that a bedrock valley may be present near the middle of the line. The interpretation of a second seismic profile across the westward extension of the same suspected valley also is not conclusive, but suggests that a bedrock valley may be present at the north end of the line. The optimal field layout for each line at the site (longer shot offsets) could not be obtained because of limited space available in the densely developed residential neighborhoods.

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USGS1985

Effects of wetlands on quality of runoff entering lakes in the Twin Cities Metropolitan Area, Minnesota

Four wetlands were compared with respect to their effectiveness in decreasing suspended solids and nutrient concentrations in runoff to lakes immediately downstream from the wetlands. An artificial impoundment in one of the wetlands increased settling of suspended solids. A decrease of nutrients in this wetland was probably the result of high assimilation rates associated with a dense stand of cattails. Two of the other three wetlands consist of open water and land areas, both of which contain abundant vegetation. Drainage from land areas within the wetlands may have lowered the overall effectiveness of the wetlands in decreasing sediment and nutrient concentrations. The third wetland was a constructed wetland that was ineffective in decreasing sediment or nutrient concentrations because its storage capacity was too small to prevent frequent flushing of accumulated sediment. Sediment concentrations in discharge from this wetland were as much as 22 times greater than the already high sediment concentrations in the inflow. (Author 's abstract)

Minnesota↗
USGS1985

Hydrologic factors affecting lake-level fluctuations in Big Marine Lake, Washington County, Minnesota

A study by the U.S. Geological Survey from 1981 through 1984, in cooperation with the Carnelian-Marine Watershed District and the Minnesota Department of Natural Resources, investigated the causes of large lake-level fluctuations at Big Marine Lake. Historic records document that Big Marine Lake has changed substantially in surface area during the period 1847 through 1983; the maximum lake-surface area was 2,300 acres in 1847, and the minimum lake-surface area was 890 acres in 1938. A change in lake level of about 11 feet caused these changes in surface area. Serious flooding of lake-shore properties has occurred in recent years because residential development commonly took place during periods of relatively low-lake level during the 1950's and 1960's. Evaporation from the lake was estimated to be approximately equal to incident precipitation on the lake surface on an annual basis. Big Marine Lake does not have a surface-water inlet, and the outlet from the lake is at an elevation well above the stage at which lake-shore property is flooded. Hydrogeologic and geochemical data collected during the study show that (1) fluctuation of water levels at Big Marine Lake is controlled primarily by ground-water discharge to and seepage from the lake, (2) water in the drift aquifer and water in the lake are chemically similar, and (3) changes in the potentiometric surface of the bedrock aquifer have minor effects on changes in lake level. Long-term trends in cumulative departure from mean annual precipitation suggest that recharge to the drift aquifer in the area has been increasing since the 1940's. The increase in precipitation and recharge corresponds to the observed rise in lake level since 1965 when regular lake-level measurements began. Fluctuations in lake level in the future will depend on changes in recharge to the drift and bedrock aquifers, which is directly related to changes in long-term precipitation patterns.

Minnesota↗
USGS1985

Can relocated wolves survive?

Considerable interest has been expressed recently in establishing gray wolves ( Canis lupus ) into parts of their former range (Bailey 1978, Weaver 1978, Klinghammer 1979, Mech 1979, Henshaw 1982). However, the proper procedure for reintroductions is debatable (Klinghammer 1979). To date, wolf relocations have been conducted in Alaska, where 5 2-year-old captive-reared wolves were released into an area occupied by wolves, (Henshaw and Stephenson 1974, Henshaw et al. 1979) and in Michigan, where a pack 4 wolves was released in a relatively wolf-free area (Weise et al. 1975). Wolf reintroductions are expensive, controversial, and attract considerable public attention. The potential for success of an effort will greatly influence the willingness of agencies to attempt reintroductions. The 9 wolves released in Alaska and Michigan had a high rate of mortality, with humans being the major cause. The present study assessed the survival and behavior of relocated wolves. We hypothesized that relocated wolves, especially pups, would have poorer survival when moved outside a familiar territory.

Minnesota↗
USGS1984

Effects of an urban wetland on sediment and nutrient loads in runoff

An urban wetland in the Minneapolis-St. Paul Metropolitan Area was found to retain sediment and nutrient loads in runoff routed through the wetland. Sediment and nutrient loads in runoff were measured during 1982 at the inlet and outlet of the 6.4-bectare urban wetland. Comparison of annual loads entering and leaving the wetland showed that retention of incoming loads in the wetland was 97 percent of nonvolatile suspended solids, 76 percent of volatile suspended solids, 48 percent of total phosphorus, 4 percent of dissolved phosphorus, 3 percent of dissolved nitrite plus nitrate nitrogen, 1 percent of total ammonia nitrogen, and 47 percent of total organic nitrogen. Flow volume was increased on an annual average basis by 5 percent between the wetland inlet and oulet. Most retention of sediment and nutrient loads occurred between late April and mid-July. Retention of sediment and nutrient loads in the wetland was associated with sedimentation processes. Dissolved nutrients generally were not retained in the wetland because the residence time of water passing through was not long enough for removal by biological processes. Effectiveness of the wetland in retaining sediment and nutrient loads in runoff varies annually. Long-term and short-term impacts of the retention of sediment and nutrients in the wetland on wetland flora and fauna are unknown.

Minnesota↗
USGS1984

The variability of Holocene climate change: Evidence from varved lake sediments

Varved sediments from a lake near the present forest-prairie border in northwestern Minnesota provide an annual record of climate change for the last 10,400 years. Climate-sensitive mineral, chemical, and biological components show that the mid-Holocene dry interval between 8500 and 4000 years ago is asymmetrical and actually consists of two distinct drier pulses separated by a moister interval that lasted about 600 years. Cyclic fluctuations with periods of several hundred years were abrupt and persistent throughout the Holocene and are most clearly recorded within the two drier pulses.

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