Camp Creek IA 04-LDM-1070

[Note 1:  A TMDL for siltation and nutrients in this segment of Camp Creek was prepared by IDNR and approved by EPA in 2005.  Because the Section 303(d) impairments identified for the 2006 assessment/listing cycle are believed addressed by the TMDL, this waterbody is placed into IR Category 4a (impaired; TMDL approved).] 

[Note 2:  Although IDNR/SHL monitoring was conducted in this segment during the 2004-2006 assessment period, only three samples were collected and analyzed.  These samples were collected at IDNR/SHL TMDL stations 11770001 and 11770002.  In addition, a sample was collected at IDNR/SHL TMDL station 11770005 near Mitchellville.  None of the three samples violated the respective Class B(WW2) criteria for ammonia, dissolved oxygen, or pH.  This amount of data is insufficient for developing an updated assessment of support of designated uses.] 

The Class B(WW2) aquatic life uses remain assessed (evaluated) as partially supporting based on results of biological sampling in 2005 and 2009.  The previous assessment of support for the Class B(WW2) aquatic life uses of this stream ("partially supported") was based on the results of IDNR biological sampling in November 1990 that suggested lower than expected diversity of aquatic life in this stream segment (see assessment developed for the 1998 report).  Results of follow-up biological and chemical monitoring conducted during the 2000-2001 biennial period suggested that, despite relatively good chemical water quality, the status of the biological community continued to suggest an impairment of the Class B(WW2) aquatic life uses. 

Results of biological sampling conducted in 2005 and 2009 as part of Section 305(b) follow-up activities suggested evaluated "partial support" of the Class B(WW2) uses.  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 2005 FIBI scores from the lower two TMDL sites located in the 47f ecoregion were 25 (poor), 39 (fair) and the BMIBI scores were 74, 75 (good).  The 2009 FIBI scores from the lower two TMDL sites located in the 47f ecoregion were 31, 39 (fair) and the BMIBI scores were 59, 68 (good).  The 47f FIBI BIC is 36 and the 47f BMIBI BIC is 51.  The upper biological sampling site is located in Thomas Mitchell County Park and is in the 47b ecoregion.  The upper site 2005 FIBI score was 30 (fair) and the BMIBI score was 73 (good).  The upper site 2009 FIBI score was 32 (fair) and the BMIBI score was 59 (good).  The 47b riffle habitat FIBI BIC is 53 and the 47b BMIBI BIC is 62.  The aquatic life use support was assessed as partially supporting (=PS), based on a comparison of the FIBI and BMIBI scores with biological impairment criteria (BIC) established for previous Section 305(b) reports.  This segment passed the FIBI BICs 2/6 times and passed the BMIBI BICs 5/6 times from 2005-2009.  The biological impairment criteria were determined from a statistical analysis of data collected at stream ecoregion reference sites from 1994-2008. 

These data are now considered too old (greater than five years) to accurately characterize current water quality conditions, the assessment category is considered “evaluated” (indicating an assessment with relatively lower confidence) as opposed to "monitored" (indicating an assessment with relatively higher confidence).