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 24 samples collected during the recreational seasons of 2012 through 2014 at the monitoring station VR40 (15330013) were as follows:  the 2012 geometric mean was 259 orgs/100 ml, the 2013 geometric mean was 701 orgs/100 ml, and the 2014 geometric mean was 239 orgs/100 ml.  All three recreation season geometric means exceeded the Class A1 geometric mean criterion of 126 orgs/100 ml.  Sixteen of the combined 24 samples (67%) 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). 

The Class B(WW2) uses remain assessed as “fully supported” based on both biological sampling and on results of chemical/physical water quality monitoring.  Results of biological sampling in 1995, 2001, 2010 and 2013 conducted as part of the IDNR/SHL stream biocriteria project and 2010, 2011, 2013 and 2014 fish sampling conducted by IDNR Fisheries Bureau suggest that the Class B(WW2) aquatic life uses should be assessed as “fully supported”.  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 1995 BMIBI score was 90 (excellent) and the 2001 BMIBI scores were 73 (good) and 80 (excellent).  The 2010 BMIBI scores were 58 and 70 (good) and the 2013 BMIBI scores were 56 and 66 (both good).  The 2010 FIBI scores were 73 and 76 (excellent) and the 2013 FIBI scores were 67 (good) and 87 (excellent).  The Fisheries Bureau 2010, 2011, 2013 and 2014 FIBI scores (n=8) ranged from 70 (good) to 86 (excellent).  The aquatic life use support was assessed as fully supporting (=FS), 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 riffle habitat FIBI BIC for this ecoregion is 65 and the natural substrate BMIBI BIC for this ecoregion is 70.  This segment passed the FIBI BIC 12/12 times in the last five years (2010-2014) and passed the BMIBI BICs 4/7 times in the last 20 years.  This aquatic life assessment is now considered "monitored" based on a change in the 2010 IDNR assessment methodology.  IDNR now requires a segment have two or more biological samples collected from the segment in multiple years over a recent five-year period to be considered “monitored”.  This segment had 12 FIBI samples collected in the last five years.

Results of chemical/physical water quality monitoring at station VR 40 (STORET station 15330013) also suggest “full support” of the aquatic life uses.  No violations of Class B(WW2) water quality criteria for ammonia (8 samples), dissolved oxygen (24 samples), temperature (23 samples, or chloride (18 samples) occurred during monitoring from April 2012 to November 2014.  One of the 24 samples (4%) analyzed violated the Class B(WW2) the pH criterion of 9.0 pH units.  According to U.S. EPA guidelines (U.S. EPA 1997b, page 3-17), a violation frequency of greater than 10% for conventional parameters such as pH suggests impairment of aquatic life uses.  Because the frequency of violations for this parameters is not greater than 10 percent, these results do not suggest impairment of the Class B(WW2) aquatic life uses.