Little Bear Creek IA 02-IOW-705
mouth (S16 T80N R13W Poweshiek Co.) to confluence with unnamed tributary in SE 1/4 NW 1/4 S29 T80N R14W Poweshiek Co.
- Cycle
- 2020
- Release Status
- Final
- Overall IR
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Unknown
- Created
- 9/3/2020 2:22:23 PM
- Updated
- 10/12/2020 1:04:33 PM
The presumptive Class A1 use remains assessed as “not supported” due to levels of indicator bacteria that exceeded state water quality standards. The Class BWW2 use remains assessed as “partially supported" based on biological sampling data. Note: A TMDL covering the bacteria impairments for all segments, with the segment code prefix "IA 02-IOW" in the Iowa River Basin, was approved by EPA in 2018. Due to the completion of the TMDL, the IR category for the Class A1 use was changed from 5p (impaired; TMDL needed) to 4a (impaired; TMDL approved). Because not all impairments identified for this segment are covered by the TMDL, this segment remains in Category 5 of Iowa's Integrated Report (impaired; TMDL needed).
Sources of
Data: Data Source Data Source ID Data Type Data Age Site ID Site Name Site Description Iowa DNR 6 WQ CY 2012-2014 15790004 Little Bear Creek at S Orchard LB4 Iowa DNR 6 WQ CY 2012-2014 15790006 Little Bear Creek at 285 Ave LB6 Iowa DNR 6 BIO See Below 523 Little Bear Creek Brooklyn – REMAP #290 Presumptive Class A1 - Indicator Bacteria: Site ID Data Source ID # Samples / # Years 2012 Geometric Mean 2013 Geometric Mean 2014 Geometric Mean Annual Geometric Mean
Violation # Violations % Violations Significantly >10%
Violations Assessment Type Support Level 15790004 6 25 / 3 1082 749 1105 Yes 24 96% Yes Evaluated Not 15790006 6 25 / 3 1266 1283 1429 Yes 24 96% Yes Evaluated Not
Class A - pH: Site ID Data Source ID # Samples / # Years Maximum Value Mean Value Median Value # Violations % Violations Significantly >10%
Violations Assessment Type Support Level 15790004 6 20 / 2 8.4 7.8 7.8 0 0% No Evaluated Full 15790006 6 20 / 2 8.2 7.8 7.9 0 0% No Evaluated Full
Class BWW2 - Conventional Parameters: Site ID Data Source ID Parameter Name # Samples / # Years Maximum Value Mean Value Median Value # Acute / Chronic
Violations % Acute/ Chronic
Violations Significantly >10%
Violations Assessment Type Support Level 15790004 6 Ammonia 10 / 1 0.2 0.09 0.07 0 / 0 0% / 0% No Evaluated Full 15790006 6 Ammonia 10 / 1 0.24 0.1 0.05 0 / 0 0% / 0% No Evaluated Full 15790004 6 Chloride 15 / 2 55 35 32 0 / 0 0% / 0% No Evaluated Full 15790006 6 Chloride 15 / 2 55 35 33 0 / 0 0% / 0% No Evaluated Full 15790004 6 Dissolved oxygen 20 / 2 14.9 8.2 7.7 NA / 2 NA / 10% No Evaluated Full 15790006 6 Dissolved oxygen 20 / 2 15 8.5 8.1 NA / 1 NA / 5% No Evaluated Full 15790004 6 pH 20 / 2 8.4 7.8 7.8 0 / NA 0% / NA No Evaluated Full 15790006 6 pH 20 / 2 8.2 7.8 7.9 0 / NA 0% / NA No Evaluated Full 15790004 6 Temperature 20 / 2 23.5 15.1 16.8 0 / 0 0% / 0% No Evaluated Full 15790006 6 Temperature 20 / 2 23.1 15.2 16.8 0 / 0 0% / 0% No Evaluated Full Class
BWW2 - Biological Sampling: Benthic
Macroinvertebrates: BioNet Site ID Date Drainage Area (mi2) Ecoregion Major Drainage/Thermal BM Sample Gear BMIBI score BMIBI Class 47f BMIBI BIT BMIBI Pass/ Fail 523 8/24/10 44 47f MS/WW ArtSub 52 Fair 51 Pass 523 8/18/05 44 47f MS/WW Surb 39 Fair 51 Fail Fish: BioNet Site ID Date Drainage Area (mi2) Ecoregion Major Drainage/Thermal Riffle Stream? FIBI score FIBI Class 47f FIBI BIT FIBI Pass/ Fail 523 8/24/10 44 47f MS/WW NA 35 Fair 36 Fail 523 8/18/05 44 47f MS/WW NA 34 Fair 36 Fail
Overall: Community Assessment Type Assessment Result Support Level Earned IR Category Actual IR Category Reason Benthic
Macroinvertebrates Evaluated Fail (1/2) Partial Fish Evaluated Fail (0/2) Partial Overall Evaluated Fail Partial 3bc 5bt Assessment
is evaluated because it included samples not collected in the last five years.