ADBNet

Assessment Comments

Assessment based on: (1) results of IDNR/SHL biological sampling near Teeds Grove in 2012 & 2013 and (2) results of routine water quality monitoring conducted at station ER02.4 from 2002 through 2004 by IDNR staff of the Upper Mississippi River "Long-Term Resource Monitoring Program (LTRMP) at Bellevue, IA). Only one sample was collected during the 2010-2012 period.

Basis for Assessment

Note:  Prior to the 2008 Section 305(b) cycle, this stream segment was designated only for Class B(WW) 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, and due to the completion of a Use Attainability Analysis, this segment is also now 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).]

SUMMARY:  The Class A1 (primary contact recreation) uses remain “not assessed” (IR 3a) due to the lack of information upon which to base an assessment.   The Class B(WW) aquatic life uses are assessed (monitored) as "fully supported" (IR 2a) based on results of biological sampling in 2012 & 2013.   Results of routine water quality monitoring conducted from 2002-2004 as part of LTRMP monitoring also do not suggest problems with chemical / physical water quality.   None of the parameters analyzed in the one sample collected during the 2010-12 period (DO, pH, and temperature) violated the respective Class B(WW1) criteria.   Fish consumption uses remain "not assessed" (IR 3a) due to the lack of fish contaminant monitoring in this stream reach.   The sources of data for this assessment include (1) results of IDNR/SHL biological sampling near Teeds Grove in 2012 & 2013 and (2) results of routine water quality monitoring conducted at station ER02.4 from 2002 through 2004 by IDNR staff of the Upper Mississippi River "Long-Term Resource Monitoring Program (LTRMP) at Bellevue, IA.  

EXPLANATION:  The Class A1 uses remain “not assessed” due to the lack of water quality information upon which to base an assessment.   LTRMP monitoring does not include sampling for indicator bacteria.  

This monitored aquatic life assessment was based on data collected in 2012 and 2013 as part of the IDNR/SHL stream biological sampling project.   A series of biological metrics which reflect stream water quality and habitat integrity were calculated from the biological sampling data.   The biological metrics are based on the numbers and types of benthic macroinvertebrate taxa and fish species 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 2012 FIBI score was 53 (good) and the BMIBI score was 52 (fair).   The 2013 FIBI score was 53 (good) and the BMIBI score was 56 (gppd).   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 FIBI BIC for this ecoregion is 36 and the BMIBI BIC for this ecoregion is 51.   This segment passed the FIBI BIC 2/2 times and passed the BMIBI BIC 2/2 times in the last five years.   The biological impairment criteria were determined from a statistical analysis of biological data collected at stream ecoregion reference sites from 1994-2008.  

This aquatic life assessment is now considered "monitored" because this segment had two or more biological samples collected in multiple years over the last five-year peiod.  

In addition to biological monitoring, this assessment is based on chemical/physical water quality data for 45 samples collected from Elk River at station ER02.4M during the period January 2002 through September 2004 as part of the Long-Term Resource Monitoring Program.   Samples were collected approximately every two weeks; samples were collected during all months of the year.   The parameters analyzed included dissolved oxygen, pH, ammonia-nitrogen, total phosphorus, total nitrogen, total suspended solids, and chlorophyll.   A summary of these data show no violations of the Class B(WW) water quality criteria for temperature, pH, dissolved oxygen, or ammonia-nitrogen in the 45 samples collected.   LTRMP monitoring has not been conducted at this station since 2004.  

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