Water Quality Status and Trends in Minnesota

Abstract

The approach taken was to examine the chemical data available on public water supplies based upon sample analyses by the Minnesota Department of Health. To utilize the published data and to establish relationships between some of the parameters, the data available were placed into a computer for easier retrieval. To characterize the quality of the various waters used as sources of supply in the State of Minnesota, a system for comparing existing quality with some accepted standards or criteria was developed. The chemical quality criteria used were based upon the U.S. Public Health Service Drinking Water Standards (USPHS/DWS) published in 1962, the Water Quality Goals Recommended by the American Water Works Association (AWWA), and the U.S. Environmental Protection Agency National Interim Primary Drinking Water Regulations (USEPA/NIPDWR). These comparison permitted as indication of the number of supplies and the populations they served that met various selected concentrations. Quality comparisons are indicated for hardness (as CaCo3), iron, manganese, chlorides, sulfates, nitrates, sodium, and filterable reside (total solids). Attempts were made to use some of the analytical data to identify specific aquifers supplying water and these results are reported in a subsequent section as are data obtained in the application of a simplified additive approach for calculating a water quality index for each supply.