Volga River IA 01-VOL-296
confluence with Little Volga R. (S2 T92N R9W Fayette Co.) to confluence with unnamed tributary in SE 1/4 S24 T93N R10W Fayette Co.
- Assessment Cycle
- 2024
- Release Status
- Pending
- Data Collection Period
- Overall IR Category
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Unknown
- Created
- 11/1/2023 8:12:24 AM
- Updated
- 2/6/2024 10:55:36 AM
Assessment Summary
The presumptive Class A1 use was assessed as “not supported” due to violations of Iowa water quality criteria for indicator bacteria (E. coli). The Class BWW2 use was assessed as “fully supported” based on biological sampling data, water quality monitoring data, and on continuous dissolved oxygen monitoring data. This segment is not designated for the Class HH use in the Iowa Surface Water Classification Document. However, a one meal/week smallmouth bass consumption advisory for mercury exists on this segment of the Volga River – see https://www.iowadnr.gov/Environmental-Protection/Water-Quality/Water-Monitoring/Fish-Tissue
Assessment Explanation
Data Sources: Data Source Data Source ID Data Type Data Age Site ID Site Name Site Description Iowa DNR 6 WQ CY 2012-2014 15330013 Volga River at Q Ave VR-40 Iowa DNR 6 BIO/WQ See Below 39 Volga River Maynard – Twin Bridges
County Park Iowa DNR 6 BIO See Below 265 Volga River Randalia – VO003 Iowa DNR 6 BIO See Below 1024 Volga River US Twin Bridges Park –
VO002 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 15330013 6 24 / 3 259 701 239 Yes 16 67% Yes Evaluated Not Site ID Data Source ID # Samples / # Years Maximum Value Mean Value Median Value # Violations % Violations Significantly >10% Violations Assessment Type Support Level 15330013 6 16 / 2 9.1 8.17 8.1 1 6.3% No Evaluated Full 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 15330013 6 Ammonia 16 / 2 0.16 0.08 0.05 0 / 0 0% / 0% No Evaluated Full 15330013 6 Chloride 16 / 2 33 31 30 0 / 0 0% / 0% No Evaluated Full 15330013 6 Dissolved oxygen 16 / 2 10 8.4 8 NA / 0 NA / 0% No Evaluated Full 15330013 6 pH 16 / 2 9.1 8.17 8.1 1 / NA 6.3% / NA No Evaluated Full 15330013 6 Temperature 15 / 2 28.2 14.8 14.2 0 / 0 0% / 0% No Evaluated Full Site ID Date Drainage Area (mi2) Ecoregion Major Drainage BM Sample Gear BMIBI score BMIBI Class 47c BMIBI BIT BMIBI Pass/Fail 39 7/25/22 53.8 47c MS Hess 76 Excellent 70 Pass 265 7/26/22 22.2 47c MS Hess 77 Excellent 70 Pass 39 7/30/18 53.8 47c MS Hess 76 Excellent 70 Pass 265 7/30/18 22.2 47c MS Hess 76 Excellent 70 Pass Site ID Date Drainage Area (mi2) Ecoregion Major Drainage Riffle Stream? FIBI score FIBI Class 47c FIBI BIT FIBI Pass/Fail 265 7/26/22 22.2 47c MS Yes 72 Excellent 65 Pass 39 7/25/22 53.8 47c MS Yes 79 Excellent 65 Pass 1024 8/28/19 56 47c MS Undetermined 80 Excellent 44/65 Pass 265 8/16/19 22.2 47c MS Yes 72 Excellent 65 Pass 1024 8/29/18 56 47c MS Undetermined 76 Excellent 44/65 Pass 265 8/22/18 22.2 47c MS Yes 72 Excellent 65 Pass 39 7/31/18 53.8 47c MS Yes 76 Excellent 65 Pass 265 7/30/18 22.2 47c MS Yes 81 Excellent 65 Pass Community Assessment Type Assessment Result Support Level IR Category Reason Benthic
Macroinvertebrates Monitored Pass (4/4) Full Fish Monitored Pass (8/8) Full 1 Assessment was monitored because multiple samples collected in Overall Monitored Pass Full a recent five year period were used to complete the assessment. Class BWW2 - Continuous
DO Monitoring: Site ID Data Source ID # Days Monitoring (2017) DO Criteria Type # 2017 violations / Violations needed for impairment Violates Annual Significantly >10% Rule? Assessment Type Support Level 24 hr 0/15 No 39 6 15 16 hr 0/15 No Evaluated Full
Presumptive Class A1 – Indicator Bacteria: 2012-2014
Presumptive Class A1 - pH: 2012-2014
Class BWW2 - Binomial Parameters: 2012-2014
Class BWW2 – Biological Sampling:
Benthic Macroinvertebrates:
Fish:
Overall:
Assessment Key Dates
| 4/4/2012 | Monitoring Start |
| 11/5/2014 | Monitoring End |
| 7/25/2022 | Biological Monitoring |
| 7/26/2022 | Biological Monitoring |
| 7/30/2018 | Biological Monitoring |
| 7/31/2018 | Biological Monitoring |
| 8/22/2018 | Biological Monitoring |
| 8/29/2018 | Biological Monitoring |
| 8/16/2019 | Biological Monitoring |
| 8/28/2019 | Biological Monitoring |
| 7/10/2017 | Monitoring Start |
| 7/24/2017 | Monitoring End |
Methods
| 150 | Monitoring data more than 5 years old |
| 200 | Physical/Chemical Monitoring |
| 315 | Regional reference site approach |
| 320 | Benthic macroinvertebrate surveys |
| 330 | Fish surveys |
| 420 | Indicator bacteria monitoring |