Platte River IA 05-PLA-6234
from confluence with tributary (T72N R31W Sec16) to Summitt Lake (T72N R31W Sec3) at Creston Union Co.
- Cycle
- 2018
- Release Status
- Final
- Overall IR
- 4 - Water is impaired or threatened and a TMDL has been completed or is not needed.
- Trend
- Unknown
- Created
- 7/25/2019 2:00:40 PM
- Updated
- 7/25/2019 2:03:33 PM
The presumptive Class A1 (primary contact recreation) uses remain "not assessed" due to a lack of water quality information upon which to base an assessment. The Class B(WW1) aquatic life uses remain assessed as "partially supported" based on results of an DNR fish kill investigations in 2007 and 2008.
The fish kill occurred on or before November 2, 2007 and was attributed to Zyglo, a green dye that was discharged by a local industry and passed through the Creston Wastewater Treatment Plant. Approximately 2,583 fish were killed in a 4.5 mile stretch of the river near Creston. The estimated value of the fish was $5,924. Because this discharge occurred through a facility with a discharge permit this assessment was placed in IR Category 5b for the 2008 assessment/listing cycle and had remained in Category 5b throughthe 2012assessment/listing cycle. 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. Fish kills attributed to authorized discharges (i.e., a wastewater discharge meeting permit limits) are considered for Section 303(d) listing (IR subcategory 5a) as the existing, required pollution control measures are not adequate to address this impairment, and a TMDL is needed. Thus, this assessment segment was placed in, and remained in, Category 5 of Iowa’s Integrated Report through the 2012 IR cycle. Also according to DNR's assessment/listing methodology, if a consent order has been issued to the party responsible for the kill and if monetary restitution has been sought for the fish killed, the affected waterbody should be placed in IR Category 4d (impaired but TMDL not required). New information showed that DNR sought and received restitution for the value of the fish kill and for the cost of the DNR investigation of the fish kill. This impairment was moved from IR Category 5b to Category 4d (impaired but TMDL not needed) for the 2014 IR cycle. Thus, this impairment will remain in IR Category 4d (impaired but TMDL not needed) for the current IR cycle. An additional kill occurred on or before September 2, 2008 and was attributed to natural causes (low flow). Approximately 1000 fish were killed. There was no evidence of contamination and the wastewater treatment facility that caused the 2007 fish kill was ruled out.