East Branch Blue Creek IA 02-CED-1880

Three fish kills occurred on this stream during the 2003-2005 period. The first of these kills occurred on or before August 1, 2003; the cause of the kill was attributed to fertilizer. An estimated 3,296 fish were killed with an estimated value of $516. Approximately one-half mile of stream was affected. The kill occurred when an ag-chemical dealer in the city of Walker drained a pit where chemicals are mixed. The water from the pit entered a ditch which is a tributary to East Branch Blue Creek. DNR indentified the party responsible for this kill and sought and received restitution.

The second of these kills occurred on or before July 10, 2004. Similar to the August 2003 kill, the cause of the kill was attributed to the accidental discharge of 4,000 gallons of water from a fertilizer tank from the same ag-chemical dealer in Walker, IA, that caused the kill in August 2003. An estimated 7,744 fish were killed with an estimated value of $1,341. Approximately 1.5 miles of stream was were affected by the kill; the kill began in Section 4 of T86N, R8W and ended in Section 9 of T86N, R8W. Restitution was also sought and received for this fish kill.

The third of these kills occurred on or before August 14, 2005. Despite a thorough investigation by DNR field staff of the potential causes and sources of the kill—especially due to the previous kills in August 2003 and July 2004—no definitive cause or source of the kill was identified. A new tile line had recently been installed. Based on conversation with the installer of the line, a hypothesis was developed that recent rains had flushed contaminated water from a low spot in the new tile line into the stream, thus causing the kill. An estimated 15 fish were killed; no estimate of valuation was calculated. The kill occurred on the south side of Walker; approximately 0.25 miles of stream were affected.

According to DNR’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 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). DNR 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. However, due to the repeated occurrence of fish kills, this segment is assessed (evaluated) as impaired and was placed in Category 5b of Iowa’s 2008 Integrated Report where it remains.