Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Boone River IA 04-UDM-1257

Otter Cr. to M Br Boone R Wright Co.

Cycle
2016
Release Status
Final
Overall IR
2 - Some of the designated uses are met but there is insufficient data to determine if remaining designated uses are met.
Trend
Unknown
Created
9/20/2016 2:34:06 PM
Updated
9/20/2016 2:34:06 PM
Use Support
Class A1
Recreation - Primary contact
Not Assessed
Class BWW1
Aquatic Life - Warm Water Type 1
Fully Supported
Class HH
Human Health -
Not Assessed
General Use
General Use water -
Not Assessed
Impairment Delistings
No delistings for this assessment cycle.
Documentation
Assessment Summary

The Class A1 (primary contact recreation) and Class HH (human health/fish consumption) uses remain "not assessed" (IR 3a) due to the lack of information upon which to base an assessment. The Class B(WW1) aquatic life uses remain assessed (evaluated) as “fully supported” (IR 2a) based on biological data collected in 2003 as part of the IDNR/SHL stream REMAP project

Assessment Explanation

[Note: Prior to the 2008 Section 305(b) cycle, this stream segment was designated only for Class B(WW) aquatic life uses, including fish consumption uses. Due to changes in Iowa’s surface water classification that were approved by U.S. EPA in February 2008 and due to the results of an Use Attainability Analysis in 2007, this segment is also now designated for Class A1 (primary contact recreation) uses. This segment remains designated for warmwater aquatic life use (now termed Class B(WW1) uses), and for fish consumption uses (now termed Class HH (human health/fish consumption uses).]

The aquatic life uses remain assessed (evaluated) as “fully supported” based on biological data collected in 2003 as part of the IDNR/SHL stream REMAP project. A series of biological metrics which reflect stream water quality and habitat integrity were calculated from the biological sampling data. The biological metrics are based on the numbers and types of fish species collected in the stream sampling reach. The biological metrics were combined to make a fish community index of biotic integrity (FIBI). The indexes rank the biological integrity of a stream sampling reach on a rising scale from 0 (minimum) to 100 (maximum). The 2003 FIBI score was 32 (fair). The aquatic life use support was assessed (evaluated) as fully supporting (=FS), based on a comparison of the FIBI score with biological impairment criteria (BIC) established for previous Section 305(b) reports. The biological impairment criteria were determined from a statistical analysis of data collected at stream ecoregion reference sites from 1994-2008. The non-riffle habitat FIBI BIC for this ecoregion is 32.

This aquatic life assessment is considered "evaluated" because there were not two or more samples collected from this segment in multiple years over a five-year period. Additionally, because these data are now considered too old (greater than five years) to accurately characterize current water quality conditions, the assessment category is considered “evaluated” (indicating an assessment with relatively lower confidence) as opposed to "monitored" (indicating an assessment with relatively higher confidence). However, despite this change in assessment methodology and type, this waterbody remains in IR Category 2a.

Monitoring and Methods
Assessment Key Dates
8/20/2003
Biological Monitoring
Methods
150
Monitoring data more than 5 years old
315
Regional reference site approach
330
Fish surveys
380
Quantitative physical habitat assessment