Langlade County depends almost exclusively on ground water pumped from the glacial sand and gravel deposits for its water needs. Well yields of 10 to 20 gallons per minute can be obtained from these deposits throughout most of the county. Yields of 500 to 1,000 gallons per minute are obtained for irrigation of crops from glacial outwash deposits in some areas of the county and particularly in the extensive 125-square-mile outwash plain in south-central Langlade County. Very low yields of less than 5 gallons per minute are obtainable for private domestic use from Precambrian crystalline rocks in areas of the county where overlying glacial material is thin. Glacial deposits are more than 400 feet thick in glacial moraine areas of east-central Langlade County; saturated thicknesses exceed 250 feet in the north-central part of the county.

Horizontal hydraulic conductivity values of glacial material range from less than 1 foot per day in fine-grained glacial tills in western parts of the county to approximately 145 feet per day in outwash deposits. The transmissivity of glacial deposits ranges from essentially zero in areas of unsaturated glacial material to more than 40,000 feet squared per day in the outwash plain of southcentral Langlade County.

Most surface and ground water originates from precipitation falling within the county. Streams and ground water flow into the county only in areas along its northern edge. Ground water supplies about 70 percent of the annual streamflow.

Ground-water composition in Langlade County is similar to most ground water in the State and is of suitable quality for most uses. It is a calcium magnesium bicarbonate type. Concentrations of total dissolved solids are relatively low and range from 71 to 369 milligrams per liter, with a median value of 144 milligrams per liter. Dissolved iron and manganese concentrations exceeded secondary (aesthetic) standards in about 30 percent of all ground-water analyses. Values for total hardness as calcium carbonate ranged from 48 to 280 milligrams per liter for all samples. Ground water classified as very hard was confined to the southern part of the county where glacial deposits are higher in carbonate mineral content.

An average of about 4.7 million gallons of water was pumped daily in Langlade County in 1983. Irrigation and fish rearing are the major ground-water uses in the county. An average of about 4.2 million gallons per day was pumped for irrigation during the months of June, July, and August. Results of this study show that present irrigation pumpage rates have little effect on groundwater levels in the Antigo Flats area.