South Fork Chariton River IA 05-CHA-1327
mouth (at Rathbun Lake) to confluence with Ninemile Cr. in S4 T69N R22W Wayne Co.
| Cycle Added | Class | Cause | Data Source | Rationale |
|---|---|---|---|---|
| 2008 | Class A1 | Bacteria: Indicator Bacteria- E. coli | TMDL monitoring: Iowa DNR | TMDL preparation and approval |
The presumptive Class A1 use remains assessed as "not supported" due to levels of indicator bacteria (E. coli) that exceeded state water quality criteria. The Class BWW2 use was assessed as “not supported” based on biological sampling data. Note: A TMDL for indicator bacteria was approved by EPA in March 2025 for this segment. The approval of this TMDL moved the bacterial impairment for this segment from Iowa's Impaired Waters List (Category 5a of the IR) to IR Category 4a (impaired; TMDL completed). Because not all impairments identified for this segment are covered by the TMDL, this segment remains in Category 5 of Iowa's Integrated Report (impaired; TMDL needed).
Data Sources: Data Source Data Source ID Data Type Data Age Site ID Site
Name Site
Description USACE 12 WQ CY 2010-2012, CY 2024 915930001 South
Fork Chariton River at CR S50/200th St. (site RA-12)
Iowa DNR 6 BIO See Below SF5 South
Fork Chariton River
Iowa DNR 6 BIO See Below SF7 South
Fork Chariton River
Iowa DNR 6 BIO See Below SF8 South
Fork Chariton River
Iowa DNR 6 BIO See Below SF9 South
Fork Chariton River
Site ID Data Source ID # Samples / # Years 2010 Geometric Mean 2011 Geometric Mean 2012 Geometric Mean Annual Geometric Mean Violation # Violations % Violations Significantly >10% Violations Assessment Type Support Level 915930001 6 19 / 3 794 1368 576 Yes 13 68% Yes Evaluated Not 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 915930001 12 6 / 1 7.47 7.81 7.68 0 3 NO EVALUATED FULL 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 915930001 12 Dissolved Oxygen 6 / 1 7.7 9.4 8.3 0 NA / NA 3 NO EVALUATED FULL 915930001 12 pH 6 / 1 7.47 7.81 7.68 0 NA / NA 3 NO EVALUATED FULL 915930001 12 Temperature 6 / 1 12.2 31.9 22.1 0 NA / NA 3 NO EVALUATED FULL Site ID Data Source ID Parameter Name # Samples / # Years Maximum Value Mean Value Median Value # Acute / Chronic Violations >1 Acute / Chronic Violation Assessment Type Support Level 915930001 12 Ammonia 6 / 1 0.134 0.06 0.02 0 / 0 NO EVALUATED FULL Fish: BioNet Site ID Date Drainage Area (mi2) Ecoregion Major Drainage Riffle Stream? FIBI score FIBI Class 40a FIBI BIT FIBI Pass/Fail SF8 7/25/02 NA 40a MO NA 21 Poor 33 Fail SF7 7/31/02 NA 40a MO NA 24 Poor 33 Fail SF5 8/26/02 NA 40a MO NA 22 Poor 33 Fail SF9 8/26/02 NA 40a MO NA 28 Poor 33 Fail Community Assessment Type Assessment Result Support Level IR Category Reason Fish Evaluated Fail (0/4) Not Assessment was
evaluated because it was based on samples Overall Evaluated Fail Not 5bt collected in a single year and not collected in a recent five-year
period.
Presumptive Class A1 -
Indicator Bacteria: 2010-2012
Presumptive Class A1 – pH:
Class BWW2 - Binomial Parameters:
Class BWW2 - Toxic Parameters:
Class BWW2 -
Biological Sampling:
Overall: