Bear Creek IA 03-SSK-958

Assessment Comments

Assessment is based on IDNR/UHL biological (biocriteria) monitoring in 1997: FIBI = 38 (fair), BMIBI = 84 (excellent). Non-riffle habitat FIBI BIC = 32, BMIBI BIC = 62.

Basis for Assessment

[Note:  Prior to the current (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.com/water/standards/files/06mar_swc.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 (2008) assessment, the available water quality monitoring data will be compared to the applicable Class A1 and Class B(WW2) water quality criteria.]

SUMMARY:  The presumptive Class A1 (primary contact recreation) uses are "not assessed" due to the lack of information upon which to base an assessment.   The Class B(WW2) aquatic life uses are assessed (evaluated) as "fully supported" based on results of IDNR/UHL biological (biocriteria) sampling in 1997.   This is the same assessment as that developed for the 2004 reporting cycle except the data are now too old for the assessment to be considered monitored; therefore, the assessment is considered evaluated.

EXPLANATION:  The assessment of the Class B(WW2) aquatic life uses was based on the 1997 data and the aquatic life use support was assessed as Fully Supported (=FS), based on a comparison of the FIBI and BMIBI scores with biological impairment criteria (BIC) established from a statistical analysis of data collected at stream ecoregion reference sites from 1994-2004.   The non-riffle habitat FIBI BIC for this ecoregion is 32 and the BMIBI BIC for this ecoregion is 62.   The FIBI score was 38 (fair) and the BMIBI score was 84 (excellent).