South River IA 04-LDM-1074
mouth (Warren Co.) to confluence with Squaw Cr. in S2 T75N R24W Warren Co.
- Assessment Cycle
- 2020
- Release Status
- Final
- Data Collection Period
- Overall IR Category
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Unknown
- Created
- 9/11/2020 1:28:31 PM
- Updated
- 10/16/2020 12:07:53 PM
Assessment Summary
The presumptive Class A1 use was assessed as "partially supported" due to levels of indicator bacteria (E. coli) that violated state water quality criteria. The Class BWW2 use was assessed as "partially supported” based on biological sampling data.
Assessment Explanation
Sources of
Data: Data Source Data Source ID Data Type Data Age Site ID Site Name Site Description Iowa DNR 6 WQ CY 2016-2018 10910003 South River near Ackworth Iowa DNR 6 BIO See Below 931 South River Ackworth Presumptive Class A1 -
Indicator Bacteria: Site ID Data Source ID # Samples / # Years 2016 Geometric Mean 2017 Geometric Mean 2018 Geometric Mean Annual Geometric Mean Violation # Violations % Violations Significantly >10% Violations Assessment Type Support Level 10910003 6 16 / 3 858.08 204.25 528.06 Yes 9 56% Yes Monitored Partial Site ID Data Source ID # Samples / # Years Maximum Value Mean Value Median Value # Violations % Violations Significantly >10% Violations Assessment Type Support Level 10910003 6 36 / 3 8.4 7.8 7.9 0 0% No Monitored 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 10910003 6 Ammonia 36 / 3 0.24 0.05 0.02 0 / 0 0% / 0% No Monitored Full 10910003 6 Chloride 36 / 3 32 13 12 0 / 0 0% / 0% No Monitored Full 10910003 6 Dissolved oxygen 36 / 3 16.9 10.3 9.8 NA / 0 NA / 0% No Monitored Full 10910003 6 pH 36 / 3 8.4 7.8 7.9 0 / NA 0% / NA No Monitored Full 10910003 6 Sulfate 36 / 3 53 35.7 38 0 / NA 0% / NA No Monitored Full 10910003 6 Temperature 36 / 3 30.4 12.9 13.5 0 / 0 0% / 0% No Monitored Full Class BWW2 -
Toxic Parameters: Site ID Data Source ID Parameter Name # Samples / # Years Maximum Value Mean Value Median Value # Acute / Chronic Violations % Acute/ Chronic Violations >1 Acute / Chronic Violation Assessment Type Support Level 10910003 6 Aluminum 9 / 2 51 8.059 0.45 0 / 0 0% / 0% No Evaluated Full 10910003 6 Arsenic 9 / 2 2 1.1 1 0 / 0 0% / 0% No Evaluated Full 10910003 6 Cadmium 9 / 2 0.07 0.037 0.025 0 / 0 0% / 0% No Evaluated Full 10910003 6 Chromium 9 / 2 0.97 0.63 0.65 0 / 0 0% / 0% No Evaluated Full 10910003 6 Copper 9 / 2 3 1.52 1.3 0 / 0 0% / 0% No Evaluated Full 10910003 6 Lead 9 / 2 0.58 0.147 0.09 0 / 0 0% / 0% No Evaluated Full 10910003 6 Nickel 9 / 2 9.4 4.6 4.4 0 / 0 0% / 0% No Evaluated Full 10910003 6 Selenium 9 / 2 1.7 0.95 0.82 0 / 0 0% / 0% No Evaluated Full 10910003 6 Zinc 9 / 2 3 1.62 1.7 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 931 8/2/18 474 47f MS/WW Float ArtSub 17 Poor 51 Fail 931 9/23/15 474 47f MS/WW Float ArtSub 51 Fair 51 Pass Overall: Community Assessment Type Assessment Result Support Level Earned IR Category Actual IR Category Reason Benthic
Macroinvertebrates Evaluated Fail (1/2) Partial 3bc 3bc Assessment
is evaluated because even though both the samples were collected in the last
five years, the results were inconclusive.
Assessment Key Dates
| 1/11/2016 | Fixed Monitoring Start Date |
| 12/4/2018 | Fixed Monitoring End Date |
| 9/23/2015 | Biological Monitoring |
| 8/2/2018 | Biological Monitoring |
Methods
| 230 | Fixed station physical/chemical (conventional plus toxic pollutants) |
| 315 | Regional reference site approach |
| 320 | Benthic macroinvertebrate surveys |
| 420 | Indicator bacteria monitoring |