Pike Run IA 02-CED-485

mouth (SW 1/4 S19 T77N R3W Muscatine Co.) to confluence with unnamed tributary in S9 T77N R3W Muscatine Co.

Open Data Collection Period Modal

For purposes of developing stream/river water quality assessments for integrated reporting, three years of water quality data are typically used for both conventional pollutant parameters (e.g., indicator bacteria) and the less frequently monitored toxic parameters (e.g., toxic metals). Since the 2004 IR cycle, DNR has used a three-year data gathering period for streams, rivers, and beaches. For most assessments, the use of three years of data increases the number of samples upon which the decision on use support is based and helps address the problem of weather-related year-to-year fluctuations in water quality.

Due to the lower sampling frequency in Iowa’s ambient lake, biological, fish kill, and fish tissue monitoring programs, five years of data are used for developing IR assessments and for identifying Section 303(d) listings.

Data Type	Data Timeframe
Beach Sampling Data	CY 2014 - 2016
Stream/River Water Quality Data	CY 2014 - 2016
Lake Water Quality Data	CY 2012 - 2016
Biological Sampling Data	CY 2012 - 2016*
Fish Kill Data	CY 2012 - 2016
Fish Tissue Sampling Data	CY 2012 - 2016
Continuous Dissolved Oxygen Sampling Data	CY 2012 - 2016
*Biological sites sampled in both 2011 and 2015 were also assessed.

Open Segment Map
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Cycle: 2018
Release Status: Final
Overall IR: 5 - Water is impaired or threatened and a TMDL is needed.
Trend: Unknown
Created: 5/13/2019 11:02:42 AM
Updated: 8/2/2019 1:25:53 PM

Use Support

Class A1

Presumptive Use

Recreation - Primary contact

Not Assessed

Class BWW1

Aquatic Life - Warm Water Type 1

Partially Supported

Biological: low aquatic macroinvertebrate IBI

Support Level

Partially Supported

Impairment Code

5b-v - Biological - verified

Cause Magnitude

Moderate

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

Low

Cycle Added

2006

Impairment Rationale

Low Biotic Index

Data Source

Biological monitoring: Iowa DNR WQMA

TMDL Priority

Tier IV

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 B(WW1) aquatic life uses are assessed (monitored) as “partially supporting” based on DNR/SHL biological sampling conducted in 2012 and 2016. The presumptive Class A1 (primary contact recreation) and Class HH (human health/fish consumption uses) uses remain "not assessed" due to the lack of information upon which to base an assessment.

Assessment Explanation

The Class B(WW1) aquatic life uses are assessed (monitored) as “partially supporting” based on data collected in 2012 and 2016 as part of the DNR/SHL stream biocriteria project. A series of biological metrics which reflect stream water quality and habitat integrity were calculated from the biocriteria sampling data. The biological metrics are based on the numbers and types of benthic macroinvertebrate taxa and fish species collected in the stream sampling reach. The biological metrics were combined to make a fish community index of biotic integrity (FIBI) and a benthic macroinvertebrate index (BMIBI). The indexes rank the biological integrity of a stream sampling reach on a rising scale from 0 (minimum) to 100 (maximum). The 2016 FIBI score was 20 (poor) the and 2016 BMIBI score was 52 (fair). The 2012 FIBI score was 31 (fair) and the 2012 BMIBI score was unavailable. The aquatic life use support was assessed as partially supporting (=PS), based on a comparison of the FIBI and BMIBI scores 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 FIBI BIC for this ecoregion is 36 and the BMIBI BIC for this ecoregion is 51. This segment passed the FIBI BIC 0/2 times and passed the BMIBI BIC 1/1 times in the last five years.

This aquatic life use assessment is considered "monitored" because there were two or more samples collected in multiple years in the most recent five year period (2012-2016).

The presumptive Class A1 (primary contact recreation) and Class HH (human health/fish consumption uses) uses remain "not assessed" due to the lack of information upon which to base an assessment.

Monitoring and Methods

Assessment Key Dates

8/2/2016

Biological Monitoring

8/20/2012

Biological Monitoring

Methods

315

Regional reference site approach

320

Benthic macroinvertebrate surveys

330

Fish surveys

380

Quantitative physical habitat assessment