[Note:  Prior to the 2008 Section 305(b) cycle, this river segment was designated only for Class B(WW1) aquatic life uses, including fish consumption uses.   Due to changes in Iowa’s surface water classification that were approved by U.S.  EPA in February 2008 (see http://www.iowadnr.com/water/standards/files/06mar_swc.pdf), this segment is presumptively designated for Class A1 (primary contact recreation) uses.   This segment remains designated for warmwater aquatic life use (now termed Class B(WW1) uses), and for fish consumption uses (now termed Class HH (human health/fish consumption uses).]

The presumptive Class A1 (primary contact recreation) uses are assessed (monitored) as "partially supported" based on levels of indicator bacteria that exceeded state water quality criteria.  The geometric means of indicator bacteria (E. coli) in the 23 samples collected during the recreational seasons of 2012 through 2014 at Soldier River near Pisgah were as follows: the 2012 geometric mean was 395 orgs/100 ml, the 2013 geometric mean was 306 orgs/100 ml, and the 2014 geometric mean was 240 orgs/100 ml.  All three recreation season geometric means exceeded the Class A1 geometric mean criterion of 126 orgs/100 ml.  Ten of the combined 23 samples (43%) exceeded Iowa’s Class A1 single-sample maximum criterion of 235 orgs/100 ml.  According to U.S. EPA guidelines for Section 305(b) reporting and IDNR’s assessment/listing methodology, if the geometric mean is greater than 126 orgs/100 ml., the primary contact recreation uses should be assessed as "impaired" (see pgs 3-33 to 3-35 of U.S. EPA 1997b).  Thus, because at least one recreation season geometric mean exceeded criteria for Class A1 uses, these uses are assessed as "partially supported".

Monitoring at the IDNR/SHL ambient water quality monitoring station near Pisgah showed no violations of Class B(WW1) water quality criteria for 36 Ammonia samples (maximum = 0.6 mg/L), 36 Dissolved Oxygen samples (minimum = 7 mg/L), 36 pH samples (range = 7.4 to 8.6), 36 Temperature samples (maximum = 30.2° c), 36 Chloride samples (maximum = 20 mg/L), or 36 Sulfate samples (maximum = 50 mg/L) occurred during monitoring from January 2012 to December 2014.   According to U.S.  EPA guidelines for Section 305(b) water quality assessments (U.S.  EPA 1997b, page 3-17), the EPA guidelines allow up to 10% violations of these conventional parameters before impairment of water quality is indicated. Thus, these results thus suggest “full support” of the Class B(WW1) aquatic life uses.

However, the results of IDNR/SHL biological monitoring in 2000, 2012 and 2013 suggest “partial support” of the aquatic life uses of this stream.   This assessment was based on data collected in 2000, 2002 and 2012 as part of the IDNR/SHL stream biocriteria project.   A series of biological metrics which reflect stream water quality and habitat integrity were calculated from the biocriteria sampling data.   The biological metrics are based on the numbers and types of benthic macroinvertebrate taxa and fish species that were collected in the stream sampling reach.   The biological metrics were combined to make a fish community index of biotic integrity (FIBI) and a benthic macroinvertebrate index (BMIBI).   The indexes rank the biological integrity of a stream sampling reach on a rising scale from 0 (minimum) to 100 (maximum).   The 2000 FIBI score was 39 (fair).   The 2012 BMIBI score was 33 (fair) and the 2013 BMIBI score was 59 (good).   The aquatic life use support was assessed (evaluated) as "partially supporting”, based on a comparison of the FIBI and BMIBI scores with biological impairment criteria (BIC) established for previous Section 305(b) reports.  The biological impairment criteria were determined from a statistical analysis of data collected at stream ecoregion reference sites from 1994-2008.   The FIBI BIC for this ecoregion is 31 and the BMIBI BIC for this ecoregion is 54.   This segment passed the FIBI BIC in 2000 and passed the BMIBI BIC 1/2 times in the last five years.

This aquatic life assessment is still considered "evaluated" even though IDNR now requires a segment have two or more biological samples collected from the segment in multiple years in a recent five year period to be considered “monitored”.   There were two BMIBI samples collected in the last five years; however, one of the samples passed and one failed, therefore the assessment is inconclusive.  There were additional BMIBI samples collected in 1999 and 2002 in this segment; however, those samples were collected outside of the current IDNR index period (7/15-10/15).  According to IDNR’s assessment/listing methodology, impairments based on “evaluated” assessments are of lesser confidence and are thus not appropriate for Section 303(d) listing (Category 5 of the Integrated Report).   IDNR does, however, consider these impairments as appropriate for listing under either Category 2b or 3b of the Integrated Report (waters potentially impaired and in need of further investigation).

Fish consumption uses remain "not assessed" due to the lack of recent fish contaminant monitoring in this river segment.