Water-quality assessment of the Indiana Dunes National Lakeshore, 1973-74
Arihood LD. 1975. Water-quality assessment of the Indiana Dunes National Lakeshore, 1973-74. Water-Resources Investigations 14-75. USGS. Indianapolis, IN
Precipitation samples collected at the National Lakeshore had average inorganic ion concentrations ranging from 0 to 7.0 milligrams per litre. Streams generally had a specific conductance ranging from 300 to 600 micromhos, an alkaline pH, and a dissolved oxygen concentration near saturation. The bogs and marshland contained water with a specific conductance ranging from 40 to 150 micromhos, an acid pH, and dissolved oxygen ranging from 0.2 to 4.0 milligrams per litre. Ground water was usually a calcium magnesium bicarbonate type and moderately to very hard (71 to 390 milligrams per litre).