Wapsipinicon River IA 01-WPS-354
from town of McIntyre (S34 T100N R15W Mitchell Co.) to north line of S20 T100N R15W Mitchell Co.
- Assessment Cycle
- 2022
- Release Status
- Final
- Data Collection Period
- Overall IR Category
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Unknown
- Created
- 12/17/2021 2:16:29 PM
- Updated
- 2/15/2022 2:37:47 PM
Assessment Summary
The Class A1 and the Class A2 uses were assessed as “not supported” due to levels of indicator bacteria (E. coli) that violated state water quality criteria. The Class BCW1 use was assessed as "not supported" based on biological sampling data, continuous dissolved oxygen and temperature monitoring data, and multiple fish kill investigations. All other designated uses were "not assessed."
Assessment Explanation
Data Sources: Data Source Data Source ID Data Type Data Age Site ID Site Name Site Description Iowa DNR 6 WQ CY2010 11660001 Wapsipinicon River Site Wap-1 Iowa DNR 6 WQ CY2010 11660002 Wapsipinicon River Site 75/Wap-2 Iowa DNR 6 WQ CY2010 12660005 Wapsipinicon River Wapsipinicon SWMA Iowa DNR 6 BIO See Below 58 Wapsipinicon River Wapsipinicon River SWMA - McIntire Iowa DNR 6 BIO See Below 689 Wapsipinicon River Wap1 - McIntire Iowa DNR 6 BIO See Below 760 Wapsipinicon River Wap2 - McIntire Site ID Data Source ID # Samples / # Years 2010 Geometric Mean Annual Geometric Mean Violation # Violations % Violations Significantly >10% Violations Assessment Type Support Level 11660001 6 29 / 2 4329 Yes 26 90% Yes Evaluated Not 11660002 6 16 / 2 920 Yes 13 81% Yes Evaluated Not 12660005 6 16 / 2 1596 Yes 15 9% Yes Evaluated Not Site ID Data Source ID # Samples / # Years 2010 Geometric Mean Annual Geometric Mean Violation # Violations % Violations Significantly >10% Violations Assessment Type Support Level 11660001 6 33 / 2 3324 Yes 13 39% Yes Evaluated Not 11660002 6 20 / 2 636 Yes 2 10% No Evaluated Not 12660005 6 20/0032 1306 Yes 3 15% No Evaluated Not Benthic
Macroinvertebrates: BioNet Site ID Date Drainage Area (mi2) Ecoregion Major Drainage/ Thermal BM Sample Gear CBI score CBI Class CBI BIT CBI Pass/ Fail 58 8/17/10 22 47c MS/CW ArtSub 37 NA 60 Fail 760 8/17/10 22 47c MS/CW Hess 43 NA 60 Fail 689 8/17/10 22 52b MS/CW ArtSub 33 NA 60 Fail 58 8/27/08 22 47c MS/CW ArtSub 37 NA 60 Fail 689 8/27/08 31 52b MS/CW ArtSub 37 NA 60 Fail Community Assessment Type Assessment Result Support Level IR Category Reason Benthic Macroinvertebrates Evaluated Fail (0/5) Not 5bv Assessment was evaluated because samples used
to complete the assessment weren’t collected in the last five years.
The 2010 combined results of continuous dissolved oxygen
(DO) and temperature monitoring at stations 11660001 (Wap-1), 11660002 (Wap-2),
and 12660005 (SWMA) do suggest impairment of Class BCW1 aquatic life uses. The
lowest DO concentration recorded in 51 combined days of continuous monitoring
at the three bioassessment sites was 3.8 mg/L. The daily DO minimum
concentration failed to meet the 24-hour DO criterion (5 mg/L) and the 16-hour
DO criterion (7 mg/L) in 7 of 51 days and 23 of 51 days, respectively. The
percentage exceeding the 24-hour criterion (14%) and was greater than (failing)
the 10% impairment threshold used to assess conventional water quality
parameters; however, the statistical analysis confidence level (< 90%) was
not high. The percentage exceeding the 16-hour criterion (45.1%) and was
greater than (failing) the 10% impairment threshold with high statistical
confidence (>90%). The maximum stream temperature recorded during the sensor
deployment period ranged from 23.3-25.7 degrees (C) among the three
bioassessment sites. The BCW1 temperature criterion of 20 (C) was exceeded in
50 of 51 days. The combined percentage exceeding (98%) was greater than
(failing) the 10% impairment threshold with high statistical confidence
(>90%). Based on these data, the BCW1 aquatic life use was assessed as
"WINOFI" due to 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. Given the extremely high frequency of temperature criteria
exceedances, follow-up continuous monitoring and an assessment of stream
thermal dynamics are strongly recommended. Class BCW1 - Fish kill Assessment: The
Class BCW1 use assessment based on the 2002 and 2016 fish kills placed this
segment in Category 5b. The fish kills were caused by a “pollutant” or was
suspected to be caused by a “pollutant”; therefore, the Class BCW1 use was
considered impaired. Because the source of the pollutant was not identified
and/or the enforcement actions taken against the responsible party have not
been resolved for all the historic fish kills, the Class BCW1 use was placed in
Category 5b. Due to uncertainty regarding the recovery of the aquatic life
following the fish kill, any existing fish kill 5b impairment will remain in
Category 5b until more recent sampling has shown recovery of the aquatic
community or the responsible party has paid restitution for all the historic
fish kills. Details
about the 2002 fish kill can be found here:https://programs.iowadnr.gov/fishkill/Events/530 Details about the 2016 fish kill can be found
here:https://programs.iowadnr.gov/fishkill/Events/917 Class HH - No Data
Class A1 - Indicator Bacteria:
Class A2 - Indicator Bacteria:
Class BCW1 - Biological Sampling:
Overall Assessment:
Class BCW1 - Continuous Monitoring:
Assessment Key Dates
| 7/29/2002 | Fish Kill |
| 8/27/2008 | Biological Monitoring |
| 3/3/2010 | Fixed Monitoring Start Date |
| 2/9/2011 | Fixed Monitoring End Date |
| 8/17/2010 | Biological Monitoring |
| 8/5/2010 | Non-fixed Monitoring Start Date |
| 9/1/2010 | Non-fixed Monitoring End Date |
| 4/28/2016 | Fish Kill |
Methods
| 140 | Incidence of spills and/or fish kills |
| 150 | Monitoring data more than 5 years old |
| 222 | Non-fixed-station monitoring (conventional during key seasons and flows) |
| 315 | Regional reference site approach |
| 320 | Benthic macroinvertebrate surveys |
| 420 | Indicator bacteria monitoring |