Renville Co. groundwater resources mapped
OLIVIA — Icelandic Glacial bottled water calls itself “super-premium” and boasts that it is sourced from the 4,500-year-old Ӧlfus Spring in Iceland.
There are residents in Renville County who could be drinking water that old too, right from their own taps and at a fraction of the cost.
Now they will have an opportunity to find out.
Letters are going out to domestic well owners in the county from the Minnesota Department of Natural Resources. It is looking for permission to test the water at 90 wells across the county as part of the Renville County Geologic Atlas project.
Those who participate will learn the age of their water, as well as information on its chemical make-up.
It’s all part of a project launched in 2009 to map the geologic and groundwater resources of the county. Maps will be developed showing the county’s aquifers and their depths. Staff from the Minnesota Geological Survey and the DNR’s Ecological and Water Resources Division are collecting and analyzing the data.
The sand and gravel aquifers that most of us rely on were laid at different times by the glaciers, explained Jan Falteisek, supervisor, DNR county atlas program.
Determining the age of the water in aquifers can help determine the rate at which those aquifers recharge.
Many aquifers in the state have recharge rates of 50 years or less.
It’s easy to identify the relatively “young” water. The geologic atlas project will test the Renville County groundwater samples for tritium, an isotope of hydrogen. It rained on the Minnesota landscape like an invisible dust collecting in the attic when above ground nuclear testing occurred 50 and 60 years ago.
The age of groundwater varies according to the underlying geology and the permeability of the soil above. There are aquifers in the state with water 10,000 years and older. In Carver County, the DNR identified an aquifer with 30,000 year-old water.
Falteisek said DNR personnel hope to collect the needed water samples from participating well owners yet this summer and autumn. Laboratory work will follow, and it will take at least 1½ to two years before all of the data can be analyzed and maps created.