When we talk about water quality, we are looking at the chemical, physical and biological attributes of a stream. The Bioassessment program pairs traditional chemical data with a Qualitative Habitat Evaluation Index (QHEI) score and fish and macroinvertebrate community data. This approach allows us to assess the health of the stream system and to identify stressors to aquatic life.
The Lower DuPage River Watershed Coalition Bioassessment Program started in 2012 at a sub-set of stations on the mainstem DuPage River and a few tributaries. The effort was expanded in 2015 to include more tributaries and smaller sites for a total of 42 stations. Sampling is completed every 3 years and in 2018 the data collected was incorporated into the update of the IPS Model.
In addition to the Bioassessment monitoring, an Expanded Dissolved Oxygen Program will be implemented in 2021 to further support the development of the Nutrient Assessment and Reduction Plan. This program incorporates week long deployments of multi-parameter probes that collect dissolved oxygen, temperature, pH and specific conductivity data every 15 minutes. During the deployment an expanded suite of water chemistry parameters are collected including sestonic (in the water column) chlorophyll-a. A benthic chlorophyll-a sample is also collected by scraping algae off of rocks for other substate in the stream. The stream cross section and flow are also measured. This information will help us to better understand how nutrients are functioning in the stream. Sites for this analysis are located downstream of wastewater treatment plants and in a few headwater areas. This program will continue for all future sampling seasons.