Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Simpson Creek IA 01-TRK-214

mouth (S30 T95NR10W Fayette Co.) to headwaters in S36 T96N R12W Chickasaw Co.

Assessment Cycle
2004
Result Period
2000 - 2002
Designations
Assessment Methodology
Assessment Type
Monitored
Integrated Report
Category 4d
Legacy ADBCode
IA 01-TRK-0445_0
Overall Use Support
Partial
Aquatic Life Use Support
Partial
Documentation
Assessment Comments

Assessment is based on the results of an IDNR investigation of a fish kill that occurred in July 2001.

Basis for Assessment

SUMMARY:  The general aquatic life uses remain assessed  (monitored) as "partiallly supported" due to a fish kill in July 2001.   This assessment is the same as that developed for the 2002 reporting cycle.

EXPLANATION:  The general aquatic life uses are assessed (monitored) as "partially supported" due to occurrence of a fish kill.   A fish kill occurred on this stream segment on July 23, 2001.   The kill affected approximately 4 miles of Simpson Creek in Sections 16, 17, 21, 22, and 27 of T95N, R11W, Chickasaw Co.   The kill was caused by discharge of hog manure; the responsible party was identified and restitution was sought.   An estimated 32,700 fish were killed.   According to DNR's assessment methodology for Section 305(b) reporting, occurrence of a single pollution-caused fish kill during the most recent three-year period indicates "partial support" of the aquatic life uses.   Thus, the general aquatic life uses of this stream were assessed as "partially supported."

Monitoring and Methods
Assessment Key Dates
7/23/2001 Fishkill
Methods
140 Incidence of spills and/or fish kills
Monitoring Levels
Biological 0
Habitat 0
Physical Chemistry 0
Toxic 0
Pathogen Indicators 0
Other Health Indicators 0
Other Aquatic Life Indicators 0
# of Bio Sites 0
BioIntegrity N/A
Causes and Sources of Impairment
Causes Use Support Cause Magnitude Sources Source Magnitude
Organic enrichment/Low DO Aquatic Life Support Moderate
  • Intensive Animal Feeding Operations
  • Moderate
Unionized Ammonia Aquatic Life Support Moderate
  • Intensive Animal Feeding Operations
  • Moderate