Jordan Creek IA 05-CHA-1330
mouth (S1 T70N R21W Wayne Co.) to confluence with unnamed tributary in E 1/2 NW 1/4 S26 T70N R21W Wayne Co.
- Cycle
- 2020
- Release Status
- Final
- Overall IR
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Stable
- Created
- 9/30/2020 10:52:00 AM
- Updated
- 10/12/2020 12:57:36 PM
The presumptive Class A1 use remains assessed as "not supported" due to levels of indicator bacteria (E. coli) that exceeded state water quality criteria. The Class BWW2 use remains assessed as “not supported” based on biological sampling data and “partially supported” based on continuous dissolved oxygen and temperature monitoring data.
Data
Sources: Data Source Data Source ID Data Type Data Age Site ID Site Name Site Description USACE 12 WQ CY 2010-2014 15930004 Jordan Creek at CR J32 (Site RA-37) Iowa DNR 6 BIO See Below 907 Jordan Creek Millerton Presumptive
Class A1 - Indicator Bacteria: 2010-2012 Site ID Data Source ID # Samples / # Years 2010 Geometric Mean 2011 Geometric Mean 2012 Geometric Mean Annual Geometric Mean Violation # Violations % Violations Significantly >10% Violations Assessment Type Support Level 15930004 12 16 / 3 1317 251 656 Yes 14 88% Yes Evaluated Not Presumptive
Class A1 - pH: 2012-2014 Site ID Data Source ID # Samples / # Years Maximum Value Mean Value Median Value # Violations % Violations Significantly >10% Violations Assessment Type Support Level 15930004 12 36 / 3 8.3 7.7 7.7 0 0% No Evaluated Full Class
BWW2 - Conventional Parameters: 2012-2014 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 15930004 12 Ammonia 22 / 3 0.67 0.09 0.05 0 / 0 0% / 0% No Evaluated Full 15930004 12 Chloride 15 / 3 16 7.7 7.6 0 / 0 0% / 0% No Evaluated Full 15930004 12 Dissolved oxygen 36 / 3 13.5 9.2 9 NA / 0 NA / 0% No Evaluated Full 15930004 12 pH 36 / 3 8.3 7.7 7.7 0 / NA 0% / NA No Evaluated Full 15930004 12 Temperature 36 / 3 28.2 17.3 18.9 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 40a BMIBI BIT BMIBI Pass/ Fail 907 9/12/12 18 40a MO/WW ArtSub 13 Poor 41 Fail Fish: BioNet Site ID Date Drainage Area (mi2) Ecoregion Major Drainage/ Thermal Riffle Stream? FIBI score FIBI Class 40a FIBI BIT FIBI Pass/ Fail 907 9/12/12 18 40a MO/WW NA 24 Poor 33 Fail Overall: Community Assessment Type Assessment Result Support Level Earned IR Category Actual IR Category Reason Benthic
Macroinvertebrates Evaluated Fail (0/1) Not
Fish Evaluated Fail (0/1) Not
Overall Evaluated Fail Not 3bc 5bt Assessment
was evaluated because it was based on an old single sample. Class BWW2 – Continuous
Monitoring Data: However,
the results of additional continuous monitoring for dissolved oxygen (DO) and
temperature do suggest impairment of the Class BWW2 uses. Continuous monitoring
data collected in 2012 by DNR/SHL for TMDL/SI purposes were examined for DO and
stream temperature criteria violations. The lowest DO concentration recorded in
29 days of continuous monitoring was 1.6 mg/L. The daily DO minimum
concentration failed to meet the 24-hour DO criterion (4 mg/L) in 19 of 29 days
and the 16-hour DO criterion (5 mg/L) in 9 of 29 days. The percentages
exceeding the 24-hour and 16-hour DO criteria (65.5% and 31.0%, respectively)
were greater than (failing) the 10% impairment threshold used to assess
conventional water quality parameters. The associated statistical analysis
confidence level was high (>90%). The maximum stream temperature recorded
during the sensor deployment period was 34.9 degrees (C). The temperature
criterion for warmwater interior streams (32 C) was exceeded in 14 of 29 days.
The percentage exceeding (48.3%) was greater than (failing) the 10% impairment
threshold with high statistical confidence (>90%). Based on these data, the
BWW2 aquatic life use is assessed as impaired for DO and temperature. The
assessment type is “evaluated” because it is based on data collected from a
single year within the current data assessment period. In order to meet the
requirements for a “monitored” assessment, the DNR’s continuous monitoring
assessment methodology requires monitoring data from two or more years within
the assessment period.