Supplemental Environmental Project

Supplemental Environmental Project (SEP)

The Mississippi and Rock Rivers are critical environmental resources for the Quad Cities’ economic and recreational life, and define the aesthetic characteristics of the entire community. Bounded on the north by the Mississippi River and on the south by the Rock River, the water supply for the cities of Moline and Rock Island (“Cities”) comes from Pools 15 and 16 of the Mississippi River.

In March 2005, the Cities began a Supplemental Environmental Project (“SEP”) to benchmark water quality conditions at various locations in the Mississippi and Rock Rivers. The project ran for 9 months (March - November) over a 2-year period (2005-2006) and documented present water quality conditions and subsequent changes that occurred in Pool 16 of the Mississippi River and the Rock River adjacent to the “Cities,” as the rivers flowed through these urbanized areas.

The goal of this study was to address the following:

  • Does water from the Mississippi and Rock Rivers meet appropriate Illinois State Water Quality Standards?
  • Is water quality on the Illinois side of the Mississippi River significantly different than water quality on the Iowa side of the Mississippi River?
  • Does water quality in the Mississippi and Rock Rivers degrade significantly as the rivers flow through the Cities?
  • Is the variability in constituent loads upstream and downstream significantly different of the Cities on the Mississippi and Rock Rivers?

The results of the SEP will supplement and enhance the findings of previous studies conducted in this area. The Quad Cities is the largest urbanized area on the Mississippi River between Minneapolis/Saint Paul, Minnesota, and Saint Louis, Missouri. The water quality data collected in the SEP is a good source of information for many agencies and could ultimately serve as the foundation to develop a comprehensive regional water quality monitoring program.

View the Supplemental Environmental Project study in its entirety.