Assessment Comments
Assessment remains based on results of an IDNR investigation of a fish kill in April 2000.
Basis for Assessment
[Note: Prior to the 2008 Section 305(b) cycle, this stream segment was designated only for Class B(LR) aquatic life uses. Due to changes in Iowa’s surface water classification that were approved by U.S. EPA in February 2008, this segment is now presumptively designated for Class A1 (primary contact recreation) uses. The stream remains designated for aquatic life uses (now termed Class B(WW2) aquatic life uses). Thus, for the current (2012) assessment, the available water quality monitoring data will be compared to the applicable Class A1 and Class B(WW2) water quality criteria.]
SUMMARY: The presumptive Class A1 (primary contact recreation) uses remain "not assessed" due to the lack of information upon which to base an assessment. The assessment of the Class B(WW2) aquatic life uses is changed from “partially supporting” (evaluated) to “not assessed”.
EXPLANATION: A fish kill occurred on this stream segment on April 6, 2000. The kill affected 6.5 miles of Deer Creek beginning at the Iowa/Minnesota state line and extending downstream at the west line, S35, T100N, R19W, Worth County; an estimated 59,000 fish were killed. The kill was caused by a fertilizer spill at an ag-chemical dealer in Myrtle, MN.
Prior to the 2012 cycle, this segment was assessed (evaluated) as "partially supported" based on the fish kill report from April 2000. Because IDNR identified the responsible party for the kill and sought restitution for the value of the fish killed, this impairment was placed in Category 4d of Iowa’s 2004 Integrated Report (impaired but TMDL not required). Due to the absence of kills in the three years subsequent to that kill, this assessment segment was considered “evaluated” and thus was moved from Category 4d to Category 3b (water in need of further investigation) of Iowa's 2006 Integrated Report. Because no additional kills have been reported for this stream for over 10 years, this segment is now being moved to IR Category 3a (not assessed) for the 2012 cycle.
