Assessment Comments
Assessment remains based on an IDNR investigation of a fish kill in August 2002.
Basis for Assessment
SUMMARY: The Class B(LR) aquatic life uses remain assessed (monitored) as “partially supported" due to occurrence of a fish kill in August 2002. This kill is believed to have been caused by animal waste.
EXPLANATION: The fish kill occurred on August 24, 2002, near the intersection of 255th Avenue and 310th Street; the kill was localized to an approximately 40-meter segment of stream; approximately 100 fish were killed. The kill was believed to be caused by manure.
According to IDNR’s 2006 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 (2002-2004) 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, because this kill occurred within the 2002-2004 assessment period, and because this kill was potentially related to a pollutant impact, this stream segment remains assessed (monitored) as "partially supported" and placed in IR Category 5b.
