Assessment Comments
Assessment remains based on results of (1) EPA/IDNR fish contaminant (RAFT) monitoring near Algona in 2002 and 2008 and (2) an IDNR investigation of a fish kill in February 2004.
Basis for Assessment
[Prior to the 2004 assessment, this segment was referred to as IA 04-EDM-0010_3. Segment IA 04-EDM-0010_3 was broken into two smaller segments, now listed as IA 04-EDM-0010_2 and IA 04-EDM-0010_3 to reflect the location descriptions and classifications (HQR) as described in the Surface Water Classification. All previous assessments referring to this segment (previously known as IA 04-EDM-0010_3) can now be found listed in the documentation for segment IA 04-EDM-0010_4.]
[Note: Prior to the 2008 Section 305(b) cycle, this stream segment was designated only for Class B(WW) aquatic life uses, including fish consumption uses. Due to changes in Iowa’s surface water classification that were approved by U.S. EPA in February 2008, and due to the completion of a Use Attainability Analysis in 2007, this segment is also now designated for Class A1 (primary contact recreation) uses. This segment remains designated for warmwater aquatic life use (now termed Class B(WW1) uses), and for fish consumption uses (now termed Class HH (human health/fish consumption uses).]
SUMMARY: The Class A1 (primary contact recreation) uses remain "not assessed" (IR 3a) due to the lack of information upon which to base an assessment. The Class B(WW1) aquatic life uses remain assessed (evaluated) (IR 2b) as "partially supported" based on occurrence of a fish kill in February 2004. Previous assessments of the aquatic life uses were based on results of biological monitoring in 2000 by IDNR Fisheres. These data are now considered too old (greter than 10 years) to accurately characterize current biological conditions. Fish consumption uses remain assessed (monitored) as "fully supported" (IR 2a) based on results of fish contaminant monitoring in 2002. The sources of data for this assessment are (1) an IDNR investigation of a fish kill in February 2004 and (2) results of U.S. EPA/IDNR fish contaminant (RAFT) monitoring near Algona in July 2002 and September 2008.
EXPLANATION: The occurrence of a fish kill in February 2004 suggests that the Class B(WW1) aquatic life uses should remain assessed (evaluated) as "partially supported". This kill occurred on or before February 10, 2004; the kill was attributed to natural causes (winterkill). An estimated 100 fish were killed. No information on the species killed was provided; no estimate of the value of the fish killed was provided. The kill affected approximately 10 miles of river. According to the IDNR investigation, dead fish were observed at three riffle sites. Dissolved oxygen readings on February 10th were extremely low (less than 1ppm) at all the riffle sites (Patterson Recreation Area, Plum Creek Dam, and Veteran’s Park). The continuance of the IR Category 2b listing is based on IDNR's assessment methodology that states the following: the occurrence of a single pollutant-caused fish kill, or a fish kill of unknown origin, on a waterbody or waterbody reach during the most recent assessment period indicates a severe stress to the aquatic community and suggests that the aquatic life uses should be assessed as “impaired”. If a cause of the kill was not identified during the IDNR investigation, or if the kill was attributed to non-pollutant causes (e.g., winterkill), the assessment type will be considered “evaluated” and will be placed in IR subcategories 2b or 3b and will be added to the state list of waters in need of further investigation. Thus, this assessment segment will remain in Category 2b of Iowa’s Integrated Report.
In contrast to the assessment of the Class B(WW1) uses based on the February 2004 fish kill, results of biological monitoring in 2000 suggested "full support" of these uses. This monitoring was conducted as part of an IDNR Fisheries stream sampling project: Manchester research station. A series of biological metrics which reflect stream water quality and habitat integrity were calculated from the Fisheries sampling data. The biological metrics are based on the numbers and types of fish species that were collected in the stream sampling reach. The biological metrics were combined to make a fish community index of biotic integrity (FIBI). The index ranks the biological integrity of a stream sampling reach on a rising scale from 0 (minimum) to 100 (maximum). The 2000 evaluated FIBI score was 39 (fair). The aquatic life use support was assessed (evaluated) as fully supporting (=FS), based on a comparison of the FIBI score with biological assessment criteria established for previous Section 305(b) reports. The biological assessment criteria were determined from a statistical analysis of data collected at stream ecoregion reference sites from 1994-2004. The non-riffle FIBI BIC for this ecoregion is 32 and this segment passed it once in 2000. [Note: previous assessments of the aquatic life uses in this segment were based on results of biological monitoring conducted in 2000. These biological data are now considered too old to be useful for characterizing current water quality or biological conditions. As water quality data age, they are less able to represent current water quality conditions. As data age beyond ten years, their ability to represent current water quality conditions is increasing suspect. Additional monitoring is needed in this assessment segment to update status of its aquatic communities.
Fish consumption uses remain assessed (monitored) as “fully supported” based on results of U.S. EPA/IDNR fish contaminant (RAFT) monitoring near Algona in 2002 and 2008. The composite samples of fillets from channel catfish and walleye in 2002 had low levels of contaminants. Levels of primary contaminants in the composite sample of channel catfish fillets were as follows: mercury: 0.069 ppm; total PCBs: <0.09 ppm; and technical chlordane: <0.03 ppm. Levels of primary contaminants in the composite sample of walleye fillets were as follows: mercury: 0.154 ppm; total PCBs: <0.09 ppm; and technical chlordane: <0.03 ppm. Follow-up sampling of walleye was conducted in 2008. The level of mercury in the composite sample of walleye fillets in 2008 was 0.14 ppm. The existence of, or potential for, a fish consumption advisory is the basis for Section 305(b) assessments of the degree to which Iowa’s lakes and rivers support their fish consumption uses. The fish contaminant data generated from the 2008 RAFT sampling conducted at this river show that the levels of contaminants do not exceed any of the advisory trigger levels, thus indicating no justification for issuance of a consumption advisory for this waterbody.
