Assessment Comments

Assessment is based on (1) results of water quality monitoring conducted for the Sny Magill / Bloody Run project and (2) IDNR summary of trout reproduction (2002).

Basis for Assessment

SUMMARY:  The Class B(CW) coldwater aquatic life uses are assessed (monitored) as "fully supported" based on results of ambient water quality monitoring conducted from 2000-02.   Fish consumption uses remain "not assessed" due to the lack of fish contaminant monitoring in this coldwater stream.   Sources of data for this assessment include (1) an updated summary of trout reproduction in Iowa streams prepared by the DNR Fisheries Bureau in April 2002 and (2) results of water quality monitoring conducted from January 2000 through September 2001 at three sites on Bloody Run Creek:  Site 1 (IDNR station 10220003), Site 2 (IDNR station 15220001), and the Spook Cave site (IDNR station 15220002).

EXPLANATION:  Based on the updated summary of trout reproduction in Iowa streams prepared by the DNR Fisheries Bureau in April 2002, the Class B(CW) uses remain assessed as "fully supported" (see assessment for the 2002 report).   According to this summary, this reach of Bloody Run Creek is in the category of Iowa trout streams that have fairly consistent natural reproduction and are capable of maintaining a viable population for the target trout species without any stocking.   This assessment is supported by results of chemical water quality monitoring conducted from 1996 through 1999 (see assessment for the 2000 report).  

The Class B(WW) aquatic life uses were also assessed as "fully supported" based on results of water quality monitoring at three monitoring sites on Bloody Run Creek conducted at Bloody Run Creek since 1992 as part of the Sny Magill Creek Nonpoint Source Pollution Monitoring Project.   The period of record and monitoring frequency varies for each of these stations:  Site 1 was monitored from January 2000 to December 2002; during most of this period, the monitoring frequency was weekly; Site 2 was sampled weekly from January 2000 through September 2001; the Spook Cave site was monitored monthly from January 2000 through September 2001.   Of the 212 samples analyzed for dissolved oxygen, only one violated the Class B(CW) water quality criterion of 7.0 mg/l:  the sample collected on June 19, 2001 contained 6.0 mg/l, thus violating this criterion.   None of the 216 samples violated Class B(CW) criteria for temperature.   None of the 15 samples analyzed for pH (Site 1 only) violated the respective Class B(CW) criteria.   None of the 15 samples analyzed for ammonia nitrogen violated the respective Class B(CW) criteria.

Fish consumption uses remain "not assessed" due to lack of fish tissue monitoring in this stream reach.

For more information on the Sny Magill Creek Nonpoint Source Pollution Monitoring Project visit the DNR-Geological Survey Bureau web site at http://www.igsb.uiowa.edu/inforsch/waterag.htm.