Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Mississippi River IA 01-NEM-62

from Lock &Dam 15 at Davenport (Scott Co.) to Lock & Dam 14 at Le Claire (Scott Co.) (= Pool 15) (Davenport water supply intake is located near river mile 484.)

Assessment Cycle
1996
Result Period
1992 - 1994
Designations
Assessment Type
Monitored
Integrated Report
Category 0
Legacy ADBCode
IA 01-NEM-0010_2
Overall Use Support
Not supporting
Aquatic Life Use Support
Threatened
Fish Consumption
Not supporting
Primary Contact Recreation
Not assessed
Drinking Water
Not assessed
Documentation
Assessment Comments

Five fish contaminant monitoring sites for ALCOA at Davenport.

Basis for Assessment

Monitoring conducted in fall 1994 continues to show levels of PCBs in carp and carpsuckers from stations along the Iowa side of Pool 15 the exceed the FDA action level (i.e., the upper 95% CI exceeds the FDA action level).   Thus, fish consumption advisory remains and the assessment of fish consumption uses = NS.   Sediment study finalized in July 1996 shows PCB levels up to 7.4 mg/kg in subsurface sediments in a relatively narrow discontinuous band 50 to 150' wide along the Iowa shore adjacent to the ALCOA facility; no PCBs detected in surface water of Pool 15.   No surface water WQ monitoring data for assessing support of the Class C (drinking water uses) for the city of Davenport.

Monitoring and Methods
Assessment Key Dates
7/20/2000 Fixed Monitoring End Date
1/30/1998 Fixed Monitoring Start Date
Methods
230 Fixed station physical/chemical (conventional plus toxic pollutants)
260 Fish tissue analysis
Monitoring Levels
Biological 0
Habitat 0
Physical Chemistry 4
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
Arsenic Drinking Water High
  • Source Unknown
  • High
Metals Drinking Water High
  • Source Unknown
  • High