Hoosier Creek IA 02-IOW-6378

Assessment Comments

Assessment is based on information from IDNR staff and from news media.

Basis for Assessment

[Note:  Prior to the 2008 Section 305(b) cycle, this stream segment was classified only for general uses.   Due to changes in Iowa’s surface water classification that were approved by U.S.   EPA in February 2008, this segment is now presumptively designated for Class A1 (primary contact recreation) uses and for Class B(WW1) aquatic life uses.   According to the Iowa Water Quality Standards, all perennial rivers and streams and all intermittent streams with perennial pools that are not specifically listed in the Iowa surface water classification are designated as Class A1 and Class B(WW1) waters.   Thus, for the current (2012) assessment, perennial flow is presumed, and the available water quality monitoring data will be compared to the applicable Class A1 and Class B(WW1) water quality criteria.]

SUMMARY:  In addition to the general uses classified for this stream, the presumptive Class A1 primary contact recreation uses and the presumptive Class B(WW1) aquatic life uses are assessed (evaluated) as "partially supported" (IR 3b) based reports of degraded water quality conditions due runoff of de-icers used at the Eastern Iowa Airport in Cedar Rapids.   The sources of information for this assessment include (1) IDNR stormwater coordinator, (2) IDNR Field Office 1, and (3) local (Cedar Rapids) news media.  

EXPLANATION:  Information from IDNR Field Office 1 at Manchester, the IDNR stormwater coordinator (Griffin), and from local news media (KGAN-TV) demonstrated severe water quality degradation in the upper portion of this segment of Hoosier Creek in spring 2009.   These conditions were attributed to runoff of de-icing agents (propylene glycol and ethylene glycol) from the Eastern Iowa Airport at Cedar Rapids.   The presence of high concentrations of glycols in surface waters can create high levels of oxygen demand such that levels of dissolved oxygen are too low to support the expected types of aquatic life (fish; aquatic macroinvertebrates).   In addition, the hypoxic and anoxic conditions can results in aesthetically objectionable conditions such as unpleasant odors.   As conditions existed spring 2009, and based on information from IDNR staff and from a media report, this segment of Hoosier Creek was likely in violation of two of Iowa's narrative water quality standards (IAC 61.3(2)) designed to protect general uses of Iowa's surface waters (e.g., livestock and wildlife watering, aquatic life and non-contact recreation):

1.   such waters shall be free from materials from wastewater discharges or agricultural practices producing objectionable color, odor, or other aesthetically objectionable conditions;

2.   such waters shall be free from substance attributable to wastewater discharges or agricultural practices in concentrations or combinations which are acutely toxic to human, animal, or plant life.  

In addition to impairment of general uses, these conditions also suggest impairment of the presumptive Class A (primary contact recreation) uses and Class B(WW1) aquatic life uses for this stream segment.  

More recent (fall 2010) information, however, suggests significant improvement in the water quality conditions in this segment of Hoosier Creek.   According to IDNR field staff, a collection system for de-icers was installed at the Eastern Iowa Airport in summer 2009 and the resultant reduction in the amount of de-icers moving to the stream has improved water quality.   Due to the potential for ongoing water quality impacts, and due to the lack in in-stream monitoring data for either chemical/physical or biological parameters, this assessment segment will be added to Iowa’s list of waters in need of further investigation.