More than 75% of Iowans rely on groundwater as their primary source of drinking water1. It's easy to see that ensuring the safety of this water supply is critical to our health and any number of quality of life issues, from economic development to the quality of food we produce.

That's why the State of Iowa has instituted a groundwater monitoring program based on three objectives:

  1. To characterize the quality of groundwater by aquifer and region
  2. To evaluate long-term trends in groundwater quality
  3. To assess new or emerging issues of groundwater quality concern

In all, there are seven major aquifer groups that provide water for Iowans:

  • alluvial aquifers;
  • sand & gravel aquifers;
  • Cretaceous (Dakota) sandstone;
  • Silurian-Devonian bedrock;
  • Mississippian bedrock;
  • Pennsylvanian bedrock; and
  • Cambrian-Ordovician bedrock (the Jordan Aquifer)


In pursuit of their objectives, the State monitored a set of municipal wells that were regularly sampled for 24 years, from 1982-2006, and again in 2012. Then, In late 2014 into 2015, additional samples were collected from selected wells in the group that were suspected to be vulnerable to surface contamination. These raw water samples were analyzed along basic water quality parameters as well as contaminants that included nutrients, pesticides, dissolved metals, volatile organic compounds (VOC’s), radionuclides, atrazine and chloroacetanilide herbicides and their degradates, and pharmaceutical compounds.

The data from these tests (and others) are readily available to the public via links on the IDNR website here.

Well-cutaway.jpgSuffice to say, the data suggests that groundwater monitoring is a necessary step in the pursuit of sustainably safe drinking water. That said, it's not the first step to be considered, nor is it as daunting a task as the casual reader might expect. The necessity for a monitoring well begins with an examination of surface water and general hydrology. Measuring and observations made in these steps contribute to a decision about the need for a monitoring well. (In most cases, these circumstances are well codified.) You can find NCRS standards here.

If a monitoring well is called for, you want a well that leaves nothing to chance in terms of compliance while keeping design and installation as efficient as possible. That suggests your first call should be to a water quality pro like MB Water. In the end, that will save you money and offer the best result.

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1Iowa Dept. of Natural Resources, 2018

2Groundwater quality data collected since 2002 from municipal water supply wells are now housed in an EQuIS database and are accessible to the public via the Iowa DNR’s Ambient Water Quality Monitoring Website, AQuIA, under the Iowa Groundwater data (IowaGW) facility. Results of grab sampling at Big Spring and St. Olaf Spring since 1993 are also available in AQuIA. Results of continuous monitoring at Big Spring and the Manchester Hatchery are available on University of Iowa’s Hydroscience and Engineering - IIHR’s Iowa Water Quality Information System (IWQIS). These and other historical groundwater data have also been included in a geodatabase which is available on the Iowa GEODATA website.