ADBNet

The Class A1 uses are assessed (evaluated) as "not supported" based on results of ambient monitoring for indicator bacteria (E.  coli).   The geometric mean level of indicator bacteria (E.  coli) in the 18 samples collected at the IDNR/UHL TMDL monitoring station at the Iowa/Minnesota state line during summer recreational seasons of 2002-2003 (180 orgs/100ml) slightly exceeds the Iowa Class A1 water quality criterion of 126 orgs/100ml.   Nine of the 18 samples (50%) exceed Iowa’s single-sample maximum criterion of 235 orgs/100 ml.   According to U.S.  EPA guidelines for Section 305(b) reporting and according to IDNR’s assessment/listing methodology, if the geometric mean level of E.  coli is greater than the state criterion of 126 orgs/100 ml., the primary contact recreation uses should be assessed as "not supported" (see pgs 3-33 to 3-35of U.S.  EPA 1997b).  

Regarding support of the Class B(WW2) aquatic life uses, results of chemical/physical water quality monitoring conducted by IDNR/UHL from March 2002 through December 2003 suggest relatively good water quality in this stream.   None of the 21 samples collected had levels of dissolved oxygen, pH, or ammonia-nitrogen that violated state water quality standards (these samples were not analyzed for toxic metals or pesticides).   These results, although somewhat limited in terms of parameter coverage, suggest "full support" of the Class B(WW2) aquatic life uses

[Note 1: Prior to the 2008 Section 305(b) cycle, this stream segment was designated only for Class B(LR) aquatic life uses.   Due to changes in Iowa’s surface water classification that were approved by U.S.  EPA in February 2008 (see http://www.iowadnr.gov/Portals/idnr/uploads/water/standards/files/swcdoc2.pdf), this segment is now presumptively designated for Class A1 (primary contact recreation) uses.   The stream remains designated for aquatic life uses (now termed Class B(WW2) aquatic life uses).   Thus, for the current assessment, the available water quality monitoring data will be compared to the applicable Class A1 and Class B(WW2) water quality criteria.]

[Note 2:  Prior to the 2016 Section 305(b) cycle, this segment was designated presumptively for Class A1 (primary contact recreation) uses.  Due to changes in Iowa’s surface water classification that were approved by then Iowa Department of Natural Resources on June 17, 2015 (seehttp://www.iowadnr.gov/Portals/idnr/uploads/water/standards/files/SWC%20-%20Final%206_17_15.pdf), this segment is now designated as Class A1 (primary contact recreation) uses and no longer considered as presumptive. Thus, for the current assessment, the available water quality monitoring data will be assessed under the Class A1 and Class B(WW2) water quality criteria.]

[Note 3:  Prior to the 2016 Section 305(b) cycle, this segment was designated presumptively for Class A1 (primary contact recreation) uses.  Due to changes in Iowa’s surface water classification that were approved by then Iowa Department of Natural Resources on June 17, 2015 (seehttp://www.iowadnr.gov/Portals/idnr/uploads/water/standards/files/SWC%20-%20Final%206_17_15.pdf), this segment is now designated as Class A1 (primary contact recreation) uses and no longer considered as presumptive. Thus, for the current assessment, the available water quality monitoring data will be assessed under the Class A1 and Class B(WW2) water quality criteria.]