Geology topics
Source-linked reports with geographic coverage including Minnesota.
Streptococcus zooepidemicus was isolated from the interstinal tract of an adult male bald eagle ( Haliaeetus leucocephalus ) found dead in Minnesota in 1974.
From Feb. 1975-May 1978, 104 wolves ( Canis lupus ) captured at or near Minnesota farms where depredations on livestock had been reported were translocated northward and eastward for 50-317 km into extensive forests; 3 others were released westward. Nine wolves were translocated twice, and 1 three times. Information on movements was obtained by radiotracking 17 wolves and by recovery of 16 others. All radio-tagged wolves left the release areas; adults left quickly, but pups generally remained longer, behaved less decisively, and settled nearby temporarily. Wolves released together did not remain together. Initial travel of most radio-tagged adults was between south and west, the general direction to their original location. Final directions were primarily to the west and northwest, due in part to physiographic barriers. Eight adults homed, 1 twice, to capture areas that were < 64 km from release sites. Nonhoming wolves were radiotracked and/or recovered 32-351 km from their capture sites and 23-302 km from their release sites. Translocation was largely unsuccessful at keeping problem wolves out of lifestock production areas. The problem of initial travel away from release sites in wolf reintroductions probably could be minimized by transport and release of 6-9 mo. old wolves.
Buried-drift aquifers are stratified sand and (or) gravel aquifers in glacial deposits that cannot be seen or inferred at the land surface. During the Pleistocene Epoch, four continental glaciations advanced and retreated across Minnesota, blanketing the bedrock surface with drift as much as 700 feet thick (fig. 1). Most of the drift consists of till, an unsorted, un-stratified mixture of clay silt, sand, and gravel that usually is not considered to be an aquifer. Permeable, stratified sand and gravel, deposited as outwash, alluvium, and (or) ice-contact deposits usually during an earlier glacial episode and subsequently covered (buried) with till, form the buried-drift aquifers.
No abstract available.
Research on the hydrology of Williams Lake, north-central Minnesota includes study of evaporation. Presented here are those climatic data needed for energy-budget and mass-transfer studies,including: water-surface temperature, dry-bulb and wet-bulb air temperatures, wind speed, precipitation, and solar radiation. Data are collected at raft and land stations.
Annual ground-water use in the Twin Cities Metropolitan Area from 1970-79 is presented by aquifer and type of use. The data show that most ground water is withdrawn from wells in the Prairie du Chien-Jordan aquifer and that major uses of the water are for self-supplied industry and public supplies. Annual ground-water-use data are presented by county for each of the five major aquifers; Prairie du Chien-Jordan, Mount Simon-Hinckley, Ironton-Galesville, St. Peter, and drift. The data also are presented by county for each major use type, including public supply, self-supplied industry, commercial air-conditioning, irrigation, lake-level maintenance, and dewatering. The data were collected initially by the Minnesota Department of Natural Resources and were supplemented by data collected by the U.S. Geological Survey.
Operation of a coal-tar distillation and wood-preserving facility in St. Louis Park, Minnesota, during 1918-72 contaminated ground water with coal-tar derivatives and inorganic chemicals. Coal-tar derivatives entered the groundwater system through three major paths: (1) Spills and drippings that percolated to the water table, (2) surface runoff and plant process water that was discharged to wetlands south of the former plant site, and (3) movement of coal tar directly into bedrock aquifers through a multiaquifer well on the site. In the drift, Platteville, and St. Peter aquifers, ground water flows laterally from west to east and vertically downward. Near the former plant site, creosote-like organic fluids have migrated vertically downward through the drift and are being partially dissolved by ground water. Ground water has preferentially mobilized low-molecular-weight compounds such as phenolic compounds, alkyl-benzenes, and naphthalene, although polynuclear aromatic hydrocarbons as heavy as benzo(a)pyrene have been mobilized at low concentrations. Sorption of high-molecular-weight compounds has retarded their migration down the hydraulic gradient compared to low-molecular-weight compounds in the plume. Some simple phenolic compounds are being degraded to methane and carbon dioxide by bacteria under anaerobic conditions in the drift-PlattevilleSt. Peter aquifer system. Other low-molecular-weight aromatic compounds are apparently being degraded by aerobic bacteria at the periphery of the plume where oxygen is available. Intermediate degradation products such as volatile fatty acids are likely present, but complete conversion of the organic contaminants to innocuous inorganic substances has not been demonstrated. Near and south of 36th and Wooddale Avenues, contaminants enter the St. Peter aquifer where the Glenwood confining unit has been eroded in a buried bedrock valley. Contaminants previously entered the Prairie du Chien-Jordan aquifer through at least one multiaquif er well (W38). Other sources of contaminants and the low concentrations of contaminants hamper delineation of the maximum areal extent of contaminants that are resistant to biologic degradation. These biorefractory compounds will probably continue to migrate down the hydraulic gradients in the drift and Platteville and St. Peter aquifers. Of particular concern with respect to the health risk to humans are the polynuclear aromatic hydrocarbons, which are a major constituent of coal tar and are found in municipal wells near the site that are completed in the Prairie du Chien-Jordan aquifer. The Prairie du Chien-Jordan aquifer lies 250 to 500 feet below land surface and is relatively well protected from nearsurface sources of contamination by overlying rocks. However, the aquifer has been contaminated since at least 1932 because coal-tar derivatives have entered the aquifer through multiaquifer wells. The most significant single source of contamination in the aquifer is a well drilled on the site in 1917 (well W23) that has contained liquid coal-tar since at least 1958. The introduction, dissolution, and movement of this coal-tar in ground water has contaminated nearby municipal wells. The composition of the tar in well W23, and the ratio of concentrations of individual compounds in water from well W23 to those in municipal well SLP15, are consistent with known hydrologic, chemical, and biologic processes, and the conclusion that contaminants in well SLP15 are due primarily to contaminants introduced at well W23. Most of the major polynuclear aromatic hydrocarbons in the tar, although slightly soluble in water and strongly sorbed by aquifer materials, have moved greater distances at higher concentrations than have the lower-molecular-weight, more soluble compounds such as phenolic compounds and naphthalene. The latter are apparently being degraded by bacteria. The direction and rate of contaminant movement within the Prairie du Chien-Jordan aquifer changes with time because the ground-water-flow system continually adjusts to hydraulic stresses caused by ground-water withdrawals and flow through multiaquifer wells. Contaminants can move rapidly through the Prairie du Chien-Jordan because the upper part of the aquifer is a carbonate rock having fracture and solution-channel permeability, low effective porosity, and relatively small surface area for sorption. Consequently, the concentration and composition of contaminants in water pumped from individual industrial and municipal wells completed in the aquifer fluctuate with time. Although contaminants have been in the aquifer for at least 50 years and their spatial distribution is complex, concentrations remain highest near their points of introduction through multiaquifer wells near and on the site of the former plant. Contaminants reached the Ironton-Galesville aquifer through at least two deep multiaquifer wells (W23 and W38), but the extent of contamination in this aquifer, and in the underlying Mount Simon-Hinckley aquifer, is not known.
Outwash deposits consisting of medium to very coarse sand constitute a major aquifer in Todd County and in parts of Cass and Morrison Counties. The outwash ranges in thickness from 0 to 150 feet. Depth to water is generally less than 15 feet, and annual water-level fluctuations are less than 5 feet. Aquifer-test results indicate that transmissivities range from 4,600 to 18,500 feet squared per day and storage coefficients range from 0.10 to 0.25. Yields of more than 2,000 gallons per minute can be obtained locally from properly constructed wells. Average annual precipitation is 25.93 inches, and average annual recharge to the aquifer is estimated to be 8 inches. Base-flow measurements of the Long Prairie River between Long Prairie and Motley during October 1978 and October 1979 indicate average net gains of 0.85 and 1.3 cubic feet per second per river mile. The water is a calcium bicarbonate type and is generally suitable for most uses. However, elevated concentrations of selected chemicals in local areas may require treatment of the water for specialized uses. The water is hard to very hard with dissolved-solids concentrations ranging from about 200 to 400 milligrams per liter. Locally, nitrate concentrations are as much as 6.4 milligrams per liter. Residuals of pesticides are present but do not exceed recommended limits as established by the U.S. Environmental Protection Agency for domestic consumption. Results from numerical modeling experiments indicate that, with proper development, the ground-water system can accommodate additional withdrawals. One experiment indicated that reduction in recharge from 8 to 4 inches annually over 4 years, and anticipated increases in pumping from 2.1 million gallons per day (1978 pumpage) to 7.7 million gallons per day, would cause water levels to decline regionally only about 9 feet and ground-water discharge to streams to decline only about 20 percent.
The ground-water system in the Twin Cities Metropolitan Area includes five aquifers; two of these aquifers the Prairie du Chien-Jordan and the Mount Simon-Hinckley supply about 80 percent and 10 percent, respectively, of the ground water pumped for public supply. Water levels and changes in water levels in these two aquifers differ greatly in the Twin Cities Metropolitan Area. The Mississippi, Minnesota, and St. Croix Rivers are in hydraulic connection with and influence the pattern of flow in the upper aquifer, the Prairie du Chien-Jordan. Water generally flows toward these streams from water-level highs northeast, northwest, and south of Minneapolis and St. Paul. Consequently, heavy pumping has caused only localized cones of depression in the potentiometric surface of this aquifer. In contrast, the Mount Simon-Hinckley, which has only a slight hydraulic connection to the streams, is greatly influenced by pumping. Pumping in the urban centers of Minneapolis and St. Paul has caused a large cone of depression in the Mount Simon-Hinckley potentiometric surface. During 1971, the measurable cone was centered in eastcentral Hennepin County, was about 25 miles in diameter, and was as much as 150 feet deep at its center. Between 1971 and 1980, average water levels in the Prairie du Chien-Jordan aquifer changed less than 5 feet in most of the study area, but rose or declined as much as 25 feet locally in response to pumpage and recharge. During this period, seasonal declines of water levels from winter to summer lessened, and the area where these declines exceeded 10 feet decreased. In contrast, between 1971 and 1980, average water levels in the Mount Simon-Hinckley aquifer rose as much as 60 feet in the center of the cone of depression in response to decreased pumping. Also, the measurable cone of depression contracted from about 25 miles to about 15 miles in diameter. However, because of increased summer pumping due to below-average precipitation during 1980, seasonal water levels declined much more and over a wider area during 1980 than in 1971. Water-level data suggest that (1) little variation in annual pumpage between 1971 and 1980 from the Prairie du Chien-Jordan aquifer produced generally stable water levels in that aquifer, (2) decreased annual pumpage from the Mount Simon-Hinckley aquifer from 1971 to 1980 caused water levels in that aquifer to rise, and (3) a greater seasonal component of pumpage from the Mount Simon-Hinckley aquifer than from the Prairie du Chien-Jordan produced larger and more widespread seasonal water-level declines in the Mount Simon-Hinckley than in the Prairie du Chien-Jordan, particularly during dry years.
Water samples were collected periodically from 124 wells completed in sand-plain aquifers in Hubbard, Morrison, Otter Tail, and Wadena Counties, Minnesota, to determine baseline water quality, provide data for evaluation of trends, and to investigate seasonal variations in concentrations of selected chemical constituents during a 3-year study that began in October 1979. Results of the study show that the water is predominantly a calcium bicarbonate type with low to moderate concentrations of dissolved solids (77 to 710 milligrams per liter), and that it generally is suitable chemically for most uses. Concentrations of most constituents are below limits for domestic consumption recommended by the Minnesota Pollution Control Agency and the U.S. Environmental Protection Agency. Concentrations of nitrite plus nitrate nitrogen, iron, and manganese in localized areas, however, exceed the recommended limits. Comparison of current data to historical data indicates that concentrations of nitrite plus nitrate nitrogen and chloride have increased in local agricultural areas. Data indicate that concentrations of certain chemical constituents vary seasonally and annually with changes in ground-water levels. This relationship suggests that chemicals infiltrate the land surface and percolate to the water table during major recharge events. Site-specific investigations at the Staples Irrigation Center near Staples, Minnesota, indicate that, in addition to seasonal variation, nitrite plus nitrate nitrogen and chloride concentrations decreased with depth while iron concentrations increased. Although no direct quantifiable relationship between concentration and depth was found, mean nitrite plus nitrate nitrogen and chloride concentrations were both 15 milligrams per liter near the top of the aquifer and were 0.1 and 3.5 milligrams per liter, respectively, near the bottom; mean concentrations of dissolved iron were 460 ug/L near the top of the aquifer and 3840 ug/L near the bottom. Data show that the stratification with depth of nitrite plus nitrate nitrogen, chloride, and iron exists at least several hundred feet from the source area throughout most of the year. Chemical stratification appears to be greatest during periods of little recharge.
The surf icial sands in the Pomme de Terre and Chippewa River valleys in Grant, Pope, Stevens, and Swift Counties have been studied to determine the occurrence, availability, and quality of ground water in these aquifers. In the northern part of the Pomme de Terre and Chippewa River valleys, the aquifers consist of coarse sand and gravel ranging from 0 to 100 feet in thickness; transmissivities range from 0 to 35,000 feet squared per day in narrow, steep-sided erosional valleys. In the north, well yields commonly exceed 1,000 gallons per minute and may be as much as 4,000 gallons per minute locally. Farther south, the deposits are medium to fine grained, range from 0 to 90 feet thick, and reach a maximum width of 10 miles near Benson, Minnesota. Transmissivities range from 0 to 25,000 feet squared per day. Wells may yield as much as 1,500 gallons per minute locally. Southeast of Clontarf, well yields generally do not exceed 500 gallons per minute because the deposits are thinly saturated and fine grained. Ground water in the surf icial aquifer is a mixed calcium magnesium-sulf ate bicarbonate type that is chemically suitable for most uses. Concentrations of most constituents analyzed were below limits recommended by the Minnesota Pollution Control Agency for drinking water, but concentrations of manganese, iron, nitrite plus nitrate, and dissolved solids exceed recommended limits locally. Salinity, as indicated by the specific conductance (values ranged from 580 to 1,000 micromhos per centimeter) was in the medium to high range at several locations. An analytical model was used to estimate the effect on streamflow of pumpage from the surficial aquifer in the narrow, 50-mile reach of the Pomme de Terre River valley in Stevens and Grant Counties. The model indicates that the 43 existing wells pumping at maximum potential yields could reduce streamflow by 55 cubic feet per second. Addition of 23 wells also pumping at maximum potential yields could reduce streamflow by 77 cubic feet per second; this rate exceeds low base flow of the Pomme de Terre River. Finite-difference models were used to simulate flow in the surficial aquifer along the Pomme de Terre River near Appleton in Swift County and along the Chippewa River between Cyrus in Pope County and Danvers in Swift County. In the Appleton area/ model analyses indicate that pumping lowered water levels as much as 3 feet from 1973-80 and reduced streamflow by about 14 cubic feet per second. Additional regional water-level declines of 1 to 2 feet/ and up to 4 feet locally near aquifer-till boundaries, can be expected after about 4 years if pumping continues at the 1980 rate and area! recharge from precipitation is near normal. However/ simulation of increased pumping rates and decreased area! recharge during a 3-year drought indicates that water levels may decline as much as 9 feet near aquifer-till boundaries and streamflow may be reduced by about 41 cubic feet per second, which is about 95 percent of the available flow in the Pomme de Terre River at the 55-percent flow duration. Model results also suggest that/ during the first year of a drought/ the combined pumpage from wells operated during 1980 along the Pomme de Terre River in Stevens and Grant Counties and in the Appleton area could reduce streamflow to zero during base flow. Model-computed streamflow deficiencies are 48 and 60 cubic feet per second at the 55- and 70-percent flow duration/ respectively. Under such conditions/ pumping could not be sustained at the rates simulated unless there was sufficient water stored in the stream channel or streamflow was augmented. In the Cyrus-Benson area/ model results indicate that tinder 1980 development and average area! recharge/ dynamic equilibrium would be reached in less than 4 years and additional drawdown would be less than 2 feet. A 3-year drought coupled with increased pumping from irrigation wells operated during 1980 would lower water levels as much as 6 feet and reduce flow in the Chippewa River by about 26 cubic feet per second. At maximum hypothetical development in terms of the number of wells and normal area! recharge/ water levels would be lowered as much as 9 feet and streamflow would be reduced about 12 cubic feet per second. At maximum hypothetical development/ drought conditions and increased pumping would lower water levels as much as 12 feet and reduce flow in the Chippewa River by about 30 cubic feet per second/ which equals about 75 percent of available streamflow at the 70-percent flow duration.
The hydrologic effects of proposed impoundments in Sherburne National Wildlife Refuge were found to be insignificant with respect to both ground- and surface-water flow patterns and water quality. Monitoring of water levels in 23 observation wells and of discharge in the St. Francis River during 1980 and 1981 has shown that ground water in the surf icial aquifer responds quickly to areal recharge and subsequently discharges to the St. Francis River. The impoundment of surface water in the refuge was not found to affect water levels in the refuge significantly. The impoundments may affect ground-water-flow systems beneath and adjacent to the impoundments. Quality of ground and surface water was found to be similar except ground water contained higher concentrations of dissolved nitrite plus nitrate nitrogen than surface water. Phytoplankton removed dissolved nitrite plus nitrate nitrogen from surface water. The effects of impoundments on water quality are expected to be minor.
The U.S. Geological Survey has begun a research project to improve understanding of the mobilization, transport, and fate of petroleum contaminants in the shallow subsurface and to use this understanding to develop predictive models of contaminant behavior. The project site is near Bemidji in northern Minnesota where an accidental spill of 10,500 barrels of crude oil occurred when a pipeline broke on August 20, 1979. Regulatory and remedial actions have been completed. The site is in a remote area with neither man-made hydraulic stresses nor other anthropogenic sources of the compounds of interest. The spill is in the recharge area of a local flow system that discharges to a small closed lake approximately 1,000 feet down the hydraulic gradient. The aquifer is pitted outwash dissected by younger glacial channels and is underlain by poorly permeable till at a depth of about 80 feet. Ground water dissolves oil floating on the water table under the spill site and moves toward the lake. At the water table, ground water enters the lake through lacustrine sediments; at depth, flow may be underneath the lake through the outwash. Contaminant transport has been as rapid as 4 feet per day based on the rate of movement of contaminants monitored through wells installed within a few days of the spill, but average rates are undoubtedly much less.
The U.S. Geological Survey has begun a research project to improve understanding of the mobilization, transport, and fate of petroleum contaminants in the shallow subsurface and to use this understanding to develop predictive models of contaminant behavior. The project site is near Bemidji in northern Minnesota where an accidental spill of 10,500 barrels of crude oil occurred when a pipeline broke on August 20, 1979. Regulatory and remedial actions have been completed. The site is in a remote area with neither man-made hydraulic stresses nor other anthropogenic sources of the compounds of interest. The spill is in the recharge area of a local flow system that discharges to a small closed lake approximately 1,000 feet down the hydraulic gradient. The aquifer is pitted outwash dissected by younger glacial channels and is underlain by poorly permeable till at a depth of about 80 feet. Ground water dissolves oil floating on the water table under the spill site and moves toward the lake. At the water table, ground water enters the lake through lacustrine sediments; at depth, flow may be underneath the lake through the outwash. Contaminant transport has been as rapid as 4 feet per day based on the rate of movement of contaminants monitored through wells installed within a few days of the spill, but average rates are undoubtedly much less.
Operation of a coal-tar distillation and wood-preserving plant from 1918 to 1972 in St. Louis Park, a suburb of Minneapolis, Minn., resulted in ground-water contamination. This preliminary evaluation presents an overview of the problem based on the results of the first year (1979) of an ongoing study. By 1932, water in the Prairie du Chien-Jordan aquifer, the region's major source of ground water, was contaminated 3,500 feet from the plant. It seems that this early contamination of the aquifer resulted in part from the introduction of coal tar directly into a multiaquifer well on the plant site. The Prairie du Chien-Jordan aquifer underlies the area at depths of 250 to 500 feet and is overlain by two bedrock aquifers (Platteville and St. Peter), two confining beds (Glenwood and the basal part of St. Peter), and 70 to 100 feet of drift. The upper part of the aquifer (the Prairie du Chien Group) is carbonate rock having fracture and solution-channel permeability and low effective porosity. Contaminants in the Prairie du Chien Group can move more rapidly than those in drift and sandstone aquifers having intergranular permeability. The aquifer characteristics, the long contamination history, and seasonal potentiometric-surface fluctuations owing to heavy municipal and industrial withdrawals combine to create a complex distribution of coal-tar derivatives in the Prairie du Chien-Jordan aquifer. In addition, at least 25 ungrouted or partly cased wells in the area may permit contaminated water from near-surface aquifers to flow downward into deeper bedrock aquifers along or through the well bores. Where possible, such wells have been geophysically logged and inspected by downhole television. Flow rates of 20 to 150 gallons per minute from the Platteville and St. Peter aquifers to the Prairie du Chien-Jordan aquifer were observed in five of nine wells. The water was contaminated in four of the five wells. Drift materials on and south of the site have been contaminated by surface spills and by infiltration of contaminated process water. Near the contamination source, a hydrocarbon fluid phase is moving vertically downward relative to movement of the aqueous phase. Fluid pumped from an observation well in this area contained 6,000 milligrams per liter total organic carbon. Dissolved coal-tar constituents in the drift and the uppermost bedrock unit over most of the area, the Platteville aquifer, have moved at least 4,000 feet downgradient to a drift-filled bedrock valley. At the valley, it seems that the Platteville aquifer and the Glenwood confining bed have been removed by erosion and that contaminants with a concentration of approximately 2 milligrams per liter dissolved organic carbon are entering the underlying St. Peter aquifer. Chemical analyses of fluid pumped from observation wells suggest that soluble, low-molecular-weight compounds are moving preferentially through the drift and the Platteville aquifer.
Sedimentary Paleozoic rocks in the Hollandale embayment in southeastern Minnesota are as thick as 2,000 ft. This sedimentary sequence, together with the Proterozoic Hinckley Sandstone and the Quaternary drift, is divided into six regional aquifers: undifferentiated drift, Upper Carbonate, St. Peter, Prairie du Chien-Jordan, Ironton-Galesville, and Mount Simon-Hinckley. Potentiometric-surface maps for each aquifer indicate that movement of ground water is predominantly toward the major rivers. The St. Croix, Minnesota, and Mississippi Rivers constitute regional discharge boundaries for ground-water flow. A major ground-water divide in the St. Peter, Prairie du Chien-Jordan, Ironton-Galesville, and Mount Simon-Hinckley aquifers in the south-central part of the Hollandale embayment separates ground-water flow northward toward the Twin Cities area and southward toward Iowa. The St. Peter and Prairie du Chien-Jordan aquifers in the southeastern part of the embayment contain ground-water mounds as high as 90 ft above the regional potentiometric surface. The mounds occur as a result of increased recharge where the Decorah-Platteville-Glenwood confining bed has been removed by erosion and the aquifers subcrop beneath drift that is about 20 ft thick. This head distribution produces a locally complex pattern of flow in which ground water moves southwesterly toward Iowa instead of directly toward the Mississippi River.
Watersheds are rural areas undergoing urbanization with current urban land use comprising 4 to 58 percent of the watershed area. The quantity and quality of storm runoff in the watersheds was tested for correlations (significance level of 0. 05) with various land-surface features and landuse characteristics. Quantity of storm runoff is not related to any single characteristic but is likely influenced by several watershed characteristics although this could not be substantiated statistically. Quality of runoff was determined by calculating the flow-weighted mean annual concentrations of four constituents - total suspended solids, total phosphorus, dissolved NO//2 plus NO//3 nitrogen, and total ammonia plus organic nitrogen.