Despite very low levels of indicator bacteria during the 2012-2014 monitoring period, the Class A1 (primary contact recreation) uses remain assessed (monitored) as “partially supported” due to a slight violation of the geometric mean criterion during the 2010 recreation season (179 org/100 ml).  The geometric means of indicator bacteria ( E. coli) in the 23 monthly samples collected during the recreational seasons of 2012 through 2014 at Bloody Run Creek, however, were very low and were below the geometric mean criterion of 126 orgs/100 ml:  the 2012 geometric mean was 45 orgs/100 ml, the 2013 geometric mean was 92 orgs/100 ml and the 2014 geometric mean was 119 orgs/100 ml.  Three of the 23 recreation season samples (13%) exceeded the Class A1 single-sample maximum criterion of 235 orgs/100 ml.  According to Iowa DNR’s assessment/listing methodology, this violation percentage is not significantly greater than 10% and thus does not indicate impairment of the Class A1 uses.

All three annual geometric means of the 35 samples collected in calendar years 2012 through 2014 (31, 49, and 54 orgs/100 ml, respectively) are far below the Class A2 geometric mean criterion of 630 orgs/100 ml.  Only one of the 36 samples (3%) exceeded the Class A2 single-sample maximum criterion of 2,880 orgs/100 ml.  These results suggest that the Class A2 uses should be assessed as “fully supporting”.  

Despite the very low levels of indicator bacteria during the 2012-2014 monitoring period, the Class A1 uses will remain assessed as “partially supporting” (IR 5p).  According to U.S. EPA guidelines for Section 305(b) reporting and IDNR’s assessment/listing methodology, if a recreation season geometric mean exceeds the respective water quality criterion, the contact recreation uses should be assessed as "impaired" (see pgs 3-33 to 3-35 of U.S. EPA 1997b).  In addition, Iowa DNR’s assessment/listing methodology states that if the violation frequency of the single sample maximum criterion for E. coli is significantly greater than 10%, then the contact recreation uses should be assessed as impaired.  The results of monitoring for indicator bacteria during the 2012-2014 period—during which all bacteria criteria were met—suggest “full support” of the Class A1 uses.  According to Iowa’s assessment/listing methodology, however, removal of an existing impairment due to violation of Iowa’s numeric water quality criteria requires that monitoring data show full support of the previously impaired beneficial use for two consecutive Integrated Report cycles.  Although results of monitoring for the current (2016) IR cycle do not suggest an impairment of the Class A1 uses due to indicator bacteria, this impairment will remain in effect due to the geometric mean violation in the previous IR cycle.  If monitoring results for the next (2018) IR cycle (i.e., monitoring years 2014-2016) also show non-impairment levels of bacteria, then this impairments should be removed.  Thus, based only on the 2010 recreation season geometric mean, the Class A1 primary contact recreation uses remain assessed (monitored) as “impaired.”  

The Class B(CW1) coldwater aquatic life uses are assessed (monitored) as “fully supported.”  This assessment is based in part on the updated summary of trout reproduction in Iowa streams prepared by the IDNR Fisheries Bureau in 2016.  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 (a Category I stream).  The Class B(CW1) aquatic life uses were also assessed (monitored) as "fully supported" based on results of water quality monitoring at Site 1 on Bloody Run Creek from 2012 through 2014.  None of the 36 monthly samples analyzed for dissolved oxygen, ammonia, temperature, pH, chloride and sulfate violated the respective Class B(CW1) aquatic life criteria. 

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