Morgan Creek IA 02-CED-513
mouth (S14 T83N R8W Linn Co.) to confluence with unnamed tributary in SW 1/4 S22 T83N R8W Linn Co.
- Cycle
- 2022
- Release Status
- Final
- Overall IR
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Unknown
- Created
- 12/30/2021 10:50:37 AM
- Updated
- 12/30/2021 10:51:43 AM
The presumptive Class A1 use remains 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 water quality monitoring data.
Data Sources: Data
Source Data
Source ID Data
Type Data
Age Site
ID Site Name Site
Description CRWQ 23 WQ CY
2018-2020 99990089 Morgan Creek
USGS 11 WQ CY
2018-2020 5464475 Morgan Creek
near Covington, IA
Presumptive Class A1 -
Indicator Bacteria: Site
ID Data
Source ID # Samples
per Year (2018/ 2019/2020) 2018
Geometric Mean 2019
Geometric Mean 2020
Geometric Mean Violates
Annual Geometric Mean? # 2018
SSM violations / SSM Violations needed for impairment # 2019
SSM violations / SSM Violations needed for impairment # 2020
SSM violations / SSM Violations needed for impairment Violates
Annual SSM Significantly >10% Rule? Assessment
Type Support
Level 99990089 23 5/5/5 748 634 413 YES 5 / NA 5 / NA 3 / NA NA Evaluated Not Presumptive Class A1 –
pH: 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 5464475 11 33 / 3 7.5 8.4 7.9 0 7 NO Monitored Full 99990089 23 15 / 3 7.65 8.08 7.87 0 4 NO Monitored Full Class BWW2 -
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 5464475 11 Ammonia 32 / 3 0.005 0.41 0.04 NA 0 / 0 6 NO Monitored Full 99990089 23 Chloride 15 / 3 18.2 34.8 28.1 NA 0 / 0 4 NO Monitored Full 5464475 11 Dissolved
Oxygen 33 / 3 7.3 17.7 11.5 0 NA /
NA 7 NO Monitored Full 99990089 23 Dissolved
Oxygen 15 / 3 6.3 15.3 9.3 0 NA /
NA 4 NO Monitored Full 5464475 11 pH 33 / 3 7.5 8.4 7.9 0 NA /
NA 7 NO Monitored Full 99990089 23 pH 15 / 3 7.65 8.08 7.87 0 NA /
NA 4 NO Monitored Full 99990089 23 Sulfate 15 / 3 22.4 44 30 0 NA /
NA 4 NO Monitored Full 5464475 11 Temperature 33 / 3 0.1 30.6 11 0 NA /
NA 7 NO Monitored Full 99990089 23 Temperature 15 / 3 8.7 22.3 17.7 0 NA /
NA 4 NO Monitored Full