Assessment Comments
Assessment remains based on occurrence of a fish kill on an unnamed tributary of the Little Volga River in September 2002. The Little Volga River was not affected by this kill.
Basis for Assessment
SUMMARY: The Class B(WW) uses of this stream are assessed (monitored) as “partially supported” due to a fish kill in September 2002. The kill was caused by animal waste. The party responsible for the kill was identified, and IDNR has sought restitution for the value of the fish killed and the costs incurred by IDNR during investigation of the kill. This impairment is appropriate for Category 4d of Iowa’s 2006 Integrated Report. Note: this assessment differs from the previous (2004) assessment: the 2004 assessment did not account for the restutution sought (and paid) by the reponsible party for the fish killed and the costs of the investigation of the kill. Thus, this waterbody is moved to IR Category 4d for the 2006 assessment/listing cycle.
EXPLANATION: The fish kill occurred on September 3, 2002, and resulted from the discharge liquid manure when a pipe failure occurred. The manure flowed to this tributary of the Little Volga River; the Little Volga River was not affected by this kill. Approximately 1.2 miles of this unnamed tributary was affected killing an estimated 12,700 fish. According to IDNR's assessment methodology for Section 305(b) reporting, occurrence of a single pollution-caused fish kill within the most recent three-year period indicates ongoing impairment of the aquatic life uses.
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 (2002-2005) 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. If, however, a consent order has been issued to the party responsible for the kill and monetary restitution has been sought for the fish killed, the affected waterbody will be placed in IR Category 4d (impaired but TMDL not required). IDNR feels that (1) TMDLs should not be required for kills caused by a one-time illegal or unauthorized release of manure or other toxic substance where enforcement actions were taken and (2) enforcement action is more appropriate, efficient, and effective for addressing a spill-related impairment than is the TMDL process.
