Geology topics

Research about Hollandale Embayment

Source-linked reports with geographic coverage including Hollandale Embayment.

3 recordsLinked to original sources

USGS1986

Hydrogeologic framework and properties of regional aquifers in the Hollandale Embayment, southeastern Minnesota

In 1977, the U.S. Geological Survey began a series of investigations of regional aquifer systems in the United States. These studies will provide quantitative information for use in developing and managing regional ground-water supplies. One of these studies, the Northern Midwest Regional Aquifer-System Analysis (RASA) project, concerns the Cambrian and Ordovician age aquifers that occur in southeastern Minnesota and in parts of five other states: Illinois, Indiana, Iowa, Missouri, and Wisconsin (Steinhilber and Young, 1979). This report describes the hydrogeologic framework and properties of the regional aquifers in the Hollandale embayment in southeastern Minnesota (fig. 1). Two other reports describing different aspects of the regional aquifers in southeastern Minnesota were also prepared. Delin and Woodward (1984) mapped the potentiometric surface of each regional aquifer, and described the regional flow regimes; and Woodward (1985) presented a summary of 100 years of water use in southeastern Minnesota based upon trends in municipal-well installations and aquifer utilization.

Minnesota↗

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.

Minnesota↗

USGS1984

Hydrogeologic setting and the potentiometric surfaces of regional aquifers in the Hollandale Embayment, southeastern Minnesota, 1970-80

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.

Minnesota↗