Rio Grande Creek IA 06-BSR-6458
from mouth (T98N R44W Sec2) to headwaters (T99N R44W Sec25 NE)
- Cycle
- 2016
- Release Status
- Final
- Overall IR
- 4 - Water is impaired or threatened and a TMDL has been completed or is not needed.
- Trend
- Unknown
- Created
- 9/6/2016 8:29:28 AM
- Updated
- 9/6/2016 10:03:44 AM
The Class A1 (primary contact recreation) uses are "not assessed" (IR 3a) based on a lack of information upon which to base an assessment. The Class B(WW1) aquatic life uses are assessed (monitored) as "partially supported" (IR 4d) based on results of a fish kill investigation in April 2011.
The fish kill occurred on April 1, 2011 and was attributed to the release of liquid nitrogen from an above ground storage tank. The kill affected 0.8 miles of Rio Grande Creek in the town of George. Approximately 1,370 fish were killed. No information on the species of fish killed was provided. The value of these fish was estimated to be $404.88. IDNR sought an received restitution from the party responsible for this kill.
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 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. Thus, this assessment segment was placed in Category 4d of Iowa’s Integrated Report and remains in Category 4d.