Shell Rock River IA 02-SHL-787
from confluence with Rose Cr. (NW 1/4 S8 T97N R19W Cerro Gordo Co.) to the Iowa/Minnesota state line.
- Cycle
- 2022
- Release Status
- Final
- Overall IR
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Unknown
- Created
- 12/28/2021 2:45:59 PM
- Updated
- 3/30/2022 9:33:03 AM
The Class A1 use remains assessed as “not supported” based on the 2006 monitoring results for indicator bacteria. The Class BWW1 use was assessed as “fully supported” based on biological sampling data and water quality monitoring data. The Class HH (fish consumption) use was assessed as "fully supported" based on fish tissue sampling data. Note: A TMDL for the bacteria impairment in the Cedar River basin was prepared and was approved by EPA in February 2010. However, this segment was not included in the TMDL; therefore, the bacteria impairment of the Class A1 primary contact recreation use for this segment remains in IR Category 5a (TMDL needed).
Data Sources: Data
Source Data
Source ID Data
Type Data
Age Site
ID Site Name Site
Description MNPCA 15 WQ CY
2018-2020 99990013 Shell Rock
River
Iowa
DNR 6 BIO See
Below 331 Shell Rock River Kensett – REMAP #23 Iowa
DNR 6 FT See
Below 110 Shell Rock River S of Northwood Site
ID Data
Source ID #
Samples / # Years 2006
Geometric Mean Annual
Geometric Mean Violation #
Violations %
Violations Significantly
>10% Violations Assessment
Type Support
Level 99990013 15 12 / 1 198 Yes 6 50% Yes Evaluated Not Site
ID Data
Source ID #
Samples / # Years 2009
Geometric Mean 2010
Geometric Mean Annual
Geometric Mean Violation #
Violations %
Violations Significantly
>10% Violations Assessment
Type Support
Level 99990013 15 15 / 2 78 84 No 2 13% No Evaluated Full Site
ID Data
Source ID #
Samples / # Years Minimum
Value Maximum
Value Mean
Value #
Violations Violations
needed for impairment Violates
Significantly >10% Rule? Assessment
Type Support
Level 99990013 15 63 / 3 6.84 9.12 8.16 1 10 NO Monitored Full Class BWW1 -
Conventional Parameters: Site
ID Data
Source ID Parameter
Name #
Samples / # Years Minimum
Value Maximum
Value Mean
Value #
Violations #
Acute / Chronic Violations Violations
needed for impairment Violates
Significantly >10% Rule? Assessment
Type Support
Level 99990013 15 Dissolved
Oxygen 65 / 3 2.7 16.5 10.3 1 NA /
NA 11 NO Monitored Full 99990013 15 pH 63 / 3 6.84 9.12 8.16 1 NA /
NA 10 NO Monitored Full 99990013 15 Temperature 66 / 3 -0.01 27.96 15.23 0 NA /
NA 11 NO Monitored Full Site
ID Date Drainage
Area (mi2) Ecoregion Major
Drainage BM
Sample Gear BMIBI
score BMIBI
Class 47c
BMIBI BIT BMIBI
Pass/Fail 331 9/17/20 306.4 47c MS Floating
Art Sub 50 Fair 52 Pass Fish: Site
ID Date Drainage
Area (mi2) Ecoregion Major
Drainage Riffle
Stream? FIBI
score FIBI
Class 47c
FIBI BIT FIBI
Pass/Fail 331 9/17/20 306.4 47c MS Yes 68 Good 65 Pass Overall: Community Assessment
Type Assessment
Result Support
Level IR
Category Reason Benthic Macroinvertebrates Evaluated Pass
(1/1) Full
Fish Evaluated Pass
(1/1) Full
Overall Evaluated Pass Full 1 Assessment was evaluated because it was based on a
single sample. Class
BWW1- Continuous DO Monitoring:
Site ID Data Source ID # Days Monitoring (2016/2017/2018/ 2019/2020) DO Criteria Type # 2016 violations /
Violations needed for impairment # 2017 violations /
Violations needed for impairment # 2018 violations
/ Violations needed for impairment # 2019 violations /
Violations needed for impairment # 2020 violations /
Violations needed for impairment Violates Annual Significantly >10% Rule? Assessment Type Support Level
24 hr NA NA NA NA 6/5 Yes
331 6 0/0/0/0/21 16 hr NA NA NA NA 1/5 No Evaluated WINOFI
Site ID Biopart Year Species # in sample / # of samples Avg Length (cm) (Avg) Hg (ppm) Chlordane (ppm) Sum PCBs (ppm) 110 fillet 2015 common carp 5 46.6 0.19 0.02 0.06 110 tissue plug 2015 walleye 5 44.5 0.218
Support Level Full
Class A1 - Indicator Bacteria: 2006
Class A1 - Indicator Bacteria: 2009-2010
Class A1 – pH:
Benthic Macroinvertebrates:
Class HH - Fish
Tissue Sampling: