Assessment Comments
Assessment is based on results of IDNR investigations of fish kills in August 2001 and August 2009.
Basis for Assessment
[Note: Prior to the 2008 Section 305(b) cycle, this stream segment was classified only for general uses. Due to changes in Iowa’s surface water classification that were approved by U.S. EPA in February 2008 (see http://www.iowadnr.com/water/standards/files/06mar_swc.pdf), this segment is now presumptively designated for Class A1 (primary contact recreation) uses and for Class B(WW1) aquatic life uses. According to the Iowa Water Quality Standards, all perennial rivers and streams and all intermittent streams with perennial pools that are not specifically listed in the Iowa surface water classification are designated as Class A1 and Class B(WW1) waters. Thus, for the current (2010) assessment, perennial flow is presumed, and the available water quality monitoring data will be compared to the applicable Class A1 and Class B(WW1) water quality criteria.]
SUMMARY: The presumptive Class A1 (primary contact recreation) uses are "not assessed" due to the lack of information upon which to base an assessment. The presumpitve Class B(WW1) aquatic life uses remain assessed (monitored) as "partially supported" based on reports of a fish kills in August 2001 and August 2009.
EXPLANATION: The most recent fish kill on this stream segment occurred on August 7, 2009. Small numbers of dead minnows were observed in the 2 miles of this stream, sections 28 and 34 of Hazleton Township. The exact cause of the kill could not be determined. No ammonia was detected and the water appeared clear or slightly turbid. The operator of a local campgroud reported that the stream had become cloudy that afternoon following several inches of rain. Two farmers in the watershed noted that the ag chemical, Headline, had recently been applied to most of the surrounding crop fields. No dead fish were found in Otter Creek.
According to IDNR’s assessment/listing methodology, 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 (2005-2007) 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 is identified, and the cause is either known, or suspected, to be a “pollutant”, the assessment type is considered “monitored” and the affected waterbody is a candidate for Section 303(d) listing. Fish kills attributed to a pollutant, but where a source of the pollutant was not identified and/or where enforcement actions were not taken against the responsible party, will be placed into Integrated Report subcategory 5b. The intent of placing these waterbodies into Category 5 is not to necessarily require a TMDL but to keep the impairment highlighted due to the potential for similar future kills from the unaddressed causes and/or sources. Thus, this assessment segment will be placed in Category 5b of Iowa’s 2010 Integrated Report.
A fish kill also occurred on this stream segment on August 18, 2001. The kill affected 1 mile of this unnamed tributary to Otter Creek in sections 33 and 28 to T90N, R9W, Buchanan County approximately 3 miles south of Hazleton. The kill was caused by movement of land-applied hog manure and waste milk to this unnamed creek. This kill was not related to rainfall runoff. The responsible party was identified and restitution was sought.
