Ballard Creek IA 03-SSK-952

The results of the DNR/SHL follow-up biological monitoring in 2007 and 2013 suggest that the Class B(WW2) aquatic life uses should be assessed (evaluated) as “partially supporting.” 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 2007 FIBI score was 43 (fair) and the BMIBI scores were 65, 61 (good). The 2013 FIBI score was 26 (fair) and the BMIBI score was unavailable. The aquatic life use support was assessed (evaluated) 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. The non-riffle habitat FIBI BIC for this ecoregion is 32 and the BMIBI BIC for this ecoregion is 62. This segment passed the FIBI BIC 1/2 times and passed the BMIBI BIC 2/2 times inthe last 10 years. One of the BMIBI samples (61) was an artificial substrate sample where the samples quality was poor due to exposed plates on the artificial substrates. Even though the BMIBI score of 61 is lower than the BMIBI BIC of 62, due to the actual score being 61.43 and sampling conditions, DNR considers it a passing score. 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 "evaluated" based on a change in the 2010 DNR assessment methodology. DNR 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 multiple BMIBI samples collected in 2007 and multiple FIBI samples in the last 10 years. According to DNR’s assessment/listing methodology, impairments based on “evaluated” assessments are of lesser confidence and are thus not appropriate for Section 303(d) listing (Category 5 of the Integrated Report). DNR does, however, consider these impairments as appropriate for listing under either Category 2b or 3b of the Integrated Report (waters potentially impaired and in need of further investigation). This evaluated assessment of partial support was erroneously added to the 2016 Section 303(d) listing (Category 5 of the Integrated Report). Until the 2016 IR cycle, the biological sampling data indicated "full support" of the Class B(WW2) aquatic life uses. The 2013 FIBI score failed and the assessment changed to "partially supporting" based on an evaluated assessment. Thus, this waterbody should have been placed in Category 3b-c (potentially impaired) but was placed in Category 5b-t.

For the 2004 cycle, a 5b fishkill impairment was identified in this segment. However, after DNR reviewed all the fish kill data in 2019, that 2002 fish kill originated and affected only the Ballard Creek IA 03-SSK-3053 segment. For more information on that fish kill, see the 2018 assessment for Ballard Creek IA 03-SSK-3053. That 5b fish kill impairment was de-listed in this segment for the 2018 IR cycle.