Publications

Electrical-resistivity logs and water-quality data were used to delineate the fresh water/saline-water interface in a 22,000-square-mile area of the central Michigan Basin, where Mississippian and younger geologic units form a regional system of aquifers and confining units. Pleistocene glacial deposits in the central Lower Peninsula of Michigan contain freshwater, except in a 1,600...

No abstract available.

Jackson Creek Wetland a 95-acre shallow prairie marsh containing three sediment retention ponds was constructed in 1992 to reduce sediment and nutrient in- flow to eutrophic Delavan Lake. The function of the wetland as a retention system for suspended sediments and nutrients (total and dissolved phosphorus, total ammonia plus organic nitrogen, dissolved ammonia, and nitrite plus nitrate...

Polychlorinated Biphenyls (PCBs) in the Great Lakes Despite being banned since the 1970's, polychlorinated biphenyls (PCBs) continue to pose a threat to the environment because of their persistence and toxicity to organisms ranging from minute algae to fish, waterfowl, and human beings. PCBs, a set of 209 related chlorinated organic compounds, had various industrial uses such as in...

In 1986, Congress appropriated funds for the U.S. Geological Survey (USGS) to develop the pilot phase of the National Water-Quality Assessment (NAWQA) Program. The long-term goals of this program are to (1) provide a nationally consistent description of current water-quality conditions for a large part of the Nation's water resources; (2) define. long-term trends (or lack of trends) in...

No abstract available.

The sand and gravel aquifer in the vicinity of the Wild Rose State Fish Hatchery is approximately 200 feet thick. The aquifer consists mostly of sand that was deposited as glacial till and outwash approximately 15,000 years ago. Hydraulic conductivity of the aquifer at the hatchery, calculated from slug tests, is approximately 18 feet per day. Ground water recharges west of the hatch ery...

In 1990, the U.S. Geological Survey (USGS) completed a study of the hydrogeology of Huron County, Michigan (Sweat, 1991). In 1993, Huron County and the USGS entered into an agreement to continue collecting water levels at selected wells throughout Huron County. As part of the agreement, the USGS has provided training and instrumentation for County personnel to measure, on a quarterly...

Water resources data for the 1995 water year for Michigan consists of records of stage, discharge, and water quality of streams; stage and contents of lakes and reservoirs; and ground water levels. This report contains discharge records for 148 streamflow-gaging stations; stage only records for 2 stream-gaging stations and 19 lake-gaging stations; stage and contents for 4 lakes and...

Sedimentary rocks of Mississippian age form the lower part of a regional aquifer system in the central Lower Peninsula of Michigan. Strata of the Michigan Formation, the Marshall Sandstone, and the Coldwater Shale were subdivided into an aquifer and two confining units on the basis of hydraulic properties. The Michigan confining unit consists of shale, limestone, dolomite, gypsum...

In 1991, the U.S. Geological Survey (USGS) began full implementation of the National Water-Quality Assessment (NAWQA) Program. The goals of the NAWQA program are to (1) provide a nationally consistent descrip- tion of water-quality conditions for a large part of the Nation's water resources, (2) define long-term trends (or lack of trends) in water quality, and (3) identify, describe, and...

This report summarizes aquatic biological studies relevant to water-quality assessment that have been done in the Western Lake Michigan Drainages from 1891 to 1996. The objective of the summary was to compile sources of biological data for the U.S. Geological Survey's National Water-Quality Assessment Program. The studies are divided into four categories: (1) populations and community...